The Clams of Drought:

Eastern Ontario field work in the summer of 2001

Frederick W. Schueler


Selections from field notes, and links to photographs, from excursions in search of native Unionid Mussels, Crayfish, Amphibians and reptiles, and Zebra Mussels in Eastern Ontario during the drought summer of 2001.

[eastern Ontario showing selected sites mentioned in the text]
modified from the
Eastern Ontario Model Forest map.


TABLE OF CONTENTS

Introduction
Unionids of the Jock River @ the Dwyer Hill Rd -28 July
Alasmigona marginata near the margins of Quebec - Galetta area 11 August
Zebra Mussels in the lowermost Mississippi Galetta - 11 August
Crayfish, drought, and Unionids in Kemptville Creek - 14 August
More Kemptville Creek Mussel News - 31 August
circum- navigation & perambulation around Glen Isle Mississippi R - 18 Sept.
South Nation River at Ventnor & Indian Creek at the Limerick Forest Access Rd - 21 Sept.
South Nation River: Casselman High Falls - 3 October
South Nation River: Zebras below the Lemieux landslide - 3 October
South Nation River: Zebras and new-to-the SNR Unionids at Jessups Falls - 3 October
South Nation River: Scotch River - Riceville and the mouth - 3 October
Zebra Mussels in Mississippi Lake - 4 October
Unionids of the Jock River @ the Dwyer Hill Rd - 4 October


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INTRODUCTION: Pulling this series of reports together as a webpage began when I'd sorted the specimens and gotten the field notes into the computer from two trips I'd taken with Bev Wigney - in pursuit of Unionids on my part, and furthering her plan of canoeing all the accessible waters of Eastern Ontario on hers. I advertised this composite document on the Unionid List, and received so many requests that I felt obliged to hang it on our website. The following accounts are edited from the output of my biographic field notes database, in the form of messages sent to the EOBM's Eastern Ontario Natural History list-serve (a venue for discussion and reporting of all aspects of natural history, to which one can subscribe by sending "subscribe eobm-nat" in the body of a message to majordomo@mail2.storm.ca ). In the following accounts, I've put links to the next account after the summary of the results at the head of each account, so you can skip the species-by-species details. Our identifications of Lampsilis and Pyganodon are tentative. Now that we are in the Bishops Mills Natural History Centre, we are moving toward having enough space to spread them out and assess variation and compare with reference material. Isabelle Picard and I are working on a formal report on this fauna, tentatively titled "The Unionid Fauna of the Ottawa River and its tributaries" - but I don't advise anyone to hold their breath until this comes out.

Lamont Cole contended (in the 1960's) that ecology is the science of the occurrence of organisms at particular times and places. While this understates the range of phenomena natural historians study, it's centrally true that we have to know where organisms are before we can say anything more about them, and that the more detailed our knowledge of their distribution, the more we can infer about their lives. Since I began working with Unionids in 1995 it has been my ambition to improve our knowledge of their distributions by visiting every bridge in eastern Ontario (and of as much of the adjacent central and northern parts of the province as I can find time for, as well as nearby Quebec and New York). Each stretch of stream or lakeshore may have a different mix of species, depending on substrate, water flow and hardness, phytoplankton, movements of host fish, and disturbance or interrupted flow over past decades. Most of our 18 species are rare, and those present in a stream may only occur at some of the sites along it. Bridges are the quickest sites to visit (though canoeing gives more thorough coverage), and a drought, since it reduces the depth of water that obscures the bottom, is the ideal season.

The eastern lobe of the province of Ontario, between the Ottawa and St Lawrence Rivers, is drained northward into the Ottawa by three major streams (counting from west to east): the Mississippi River (originating on the Canadian Shield, and running along the edge of the Shield through Lanark County), the Rideau River (draining limestone terrain, man-handled into a canal in the 1830's and over-run, in the 1990's, in the lower reaches, by Zebra Mussels), and the South Nation River (a vast agricultural basin of Champlain Sea post-glacial clay, interrupted by limestone sills - Zebra Mussels have been in the lower stretches since 1999). A series of much smaller streams and rivers drain south to the St Lawrence, which has been dominated by Zebra Mussels since the late 1980's.

Most of the Unionid species of the Ottawa area were documented by collections made by J.B. Tyrrell and F.R. Latchford in 1881-1882. H.M. Ami made 10 dated collections along the Ottawa River from 1885-1906, and there was some collecting through the first three decades of the 20th century. In the 1930's there was more collecting, still mostly in Ottawa, led by A. LaRocque. There was almost no more collecting until A.H. Clarke came to the National Museum (now the Canadian Museum of Nature as curator of malacology in 1959. He collected fairly actively in the area until 1967, ranging more widely than his predecessors, but still concentrating on the Ottawa and Rideau Rivers and the larger lakes. This activity was not directed towards a systematic survey of the Unionids of the area, and resulted in few or no collections from many drainages.

I've reported on my search for Unionids in Eastern Ontario in the Triannual Unionid Reports for the 1995 and 1996 field seasons (these take a while to load, you may have to scroll down to find the link to the individual accounts). The Canadian Museum of Nature has posted a brief summary of their exhaustive survey of Unionids of the lower Rideau River.

So in the extreme summer drought of 2001 I was out, not as often as I'd have liked, to numerous bridges, some that I monitor more or less regularly, and some where the Unionid collector can say - "Nobody's ever been here before." Isabelle Picard, Jean-Francois Desroches, Eric Snyder, Jhil Kar, Matthew Scott, Jennifer Schueler, and Aleta Karstad have been with me on some of these trips, and Tim Haxton, Bev Wigney, Peggi Calder, and the South Nation drainage assessment project have brought in shells from other sites. Two of the trips were taken with Bev Wigney, as part of her survey of all the canoe-able streams of Eastern Ontario.

In addition to the visits reported here, we visited the Mississippi River at the Dwyer Hill Rd (no Zebras), Almonte (Two-lined Salamanders, Eurycea bisleneata, persist), and Ferguson Falls (confirming the introduced crayfish, Orconectes obscurus). and the Jock River at Munster Side Road (Crayfish hybrids between the native Orconectes propinquus and the invading Orconectes rusticus), Richmond (Unionids not much affected by low water, hybrid Crayfish present), and Greenbank Road (diverse Unionids and Orconectes rusticus persist). In the Rideau River at Kilmarnock, Burritts Rapids, and Andrewsville Zebras continue to be rare or absent, while at the Old Hwy 16 bridge north of Kemptville they cover all hard substrates, though Elliptio and Lampslis radiata survive, and a little downstream at rideau Provincial Park we added Utterbackia imbecillis to the Rideau list. We found only native Orconectes virilis and Orconectes propinquus in these Rideau sites, though in little Brassils Creek (which enters the Rideau just above Burritts Rapids and in its lower stretches doesn't have any flow in most summers) we found dwarfed Orconectes rusticus at Paden Road.

Also the Indian River at Clayton & at Co Rd 9, Payne Creek at Berwick, the Carp River at its mouth & at Galetta Sideroad, Bear Creek at Pierrepont Manor (NY), Rideau Creek & its north branch at Richardson Road, White, Westport, Crowe, and Upper & Lower Beverley lakes at municipal parks, Mill Creek at Delta, and the Tay River at Co Rd 36. We made the first surveys of Unionids in the North Branch of the South Nation (at Co Rd 20 & Inkerman), and in the Little Castor River. In the free-running section of the Ottawa River at Portage du Fort, and north of Ile du Grand Calumet and Ile des Allumettes, we found an excitingly diverse Unionid fauna (including the first Ottawa drainage sites where the compactly graceful Olivaria obovaria is abundant), and the first Quebec records of Orconectes obscurus.. On the course of my annual trip to my Anuran monitoring site in northeastern Ontario, I confirmed reports of the introduced Chinese Mystery Snail, Cipangopaludina chinensis, in the Ottawa at Pembroke, and the Mattawa River above the Mattawa dam, and sampled Unionids at numerous sites in northeastern Ontario and northwestern Quebec. For further details about any of the trips, or about particular specimens, email me at bckcdb@istar.ca. Since posting field notes like these is a lot of work, and a bit of a novelty, I'd also like to hear from anyone who finds them instructive or useful.

fred schueler, Bishops Mills, Ontario, 29 October 2001. - skip back to contents


Subject: [NatureList] Unionids of the Jock River @ the Dwyer Hill Rd
Date:Thu, 02 Aug 2001 17:34:03 -0400
To: Eastern Ontario NatureList

Everyone,

On Saturday, after a ramble through a North Goulbourn wetland treatened by quarry drainage water, Eric Snyder and I stopped at the upper Jock River at the Dwyer Hill Road, to see how much flow remained in the stream, and to see how the Unionids there were doing. We found seven species, many preyed on by Raccons due to low water level. We picked up every shell, but didn't collect any living animals. The water is so low that there is no surface flow between pools, and the muddy riffle above the bridge is dry. We sampled under the bridge span (ES) and about 100 m upstream of the bridge (FWS), but didn't follow the shore downstream, which is likely a Castor impoundment.

Many of the shells have strikingly distinct beak sculpture, and some of the series include very small shells. 'Coons seem to have cleaned out all the Unionids in the dry riffle above the bridge, muching and puncturing the shells much more than Muskrats do. We found the same species as in 1996, with the addtion of Lasmigona costata, and many more Lasmigona compressa - this is roughly half of the entire local fauna, an impressive showing for such a small stream, and a real incentive to the Friends of the Jock River to insist that Unionids be given some recognition in the forthcoming watershed plan. The species are listed here in order of decreasing abundance. skip to contents - skip to next


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Field notes of Frederick W. Schueler -- 28 July 2001
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Canada: Ontario: Ottawa-Carleton Region: Goulbourn: Jock R/Dwyer Hill Rd. 31G/4, UTM 18TVF 233.6 0.2 45.15151N 75.97453W. TIME: 1430-1502. AIR TEMP: 26, sunny, breezy. HABITAT: rocky muddy slow creek in ungrazed pasture, no flow, water turbid, 22 C. OBSERVER: Frederick W. Schueler, Eric Snyder.

2001/144/adb, Elliptio complanata (Eastern Elliptio) (Mollusca). 56+many adult, shell, specimen, seen. many alive, 48 pairs, 8 valves, largest 100 mm. Many with very distinct beak sculpture.

2001/144/adf, Strophitus undulatus (Squaw-Foot) (Mollusca). 21+few adult, shell, specimen, seen. 2 alive, 19 pairs, 3 valves, largest 86 mm, many small. Mostly upstream of the bridge, some with Procyon tooth holes.

2001/144/ade, Anodontoides ferussacianus (Cylindrical Floater) (Mollusca). 16+few adult, shell, specimen, seen. few alive, 9 pairs, 7 valves, largest 60 mm, many small. Mostly upstream of the bridge, some with Procyon tooth holes, a nice series showing the transition btween the compressed juvenile shell to the cylindrical adult shell.

2001/144/adc, Pyganodon grandis (Common Floater) (Mollusca). 11+few adult, shell, specimen, seen. few alive, 3 pairs, 8 valves, largest 84 mm. Low umbos, crimped/nodulous beak sculpture.

2001/144/add, Lasmigona compressa (Brook Lasmigona) (Mollusca). 9+2 adult, shell, specimen, seen. 2 large inflated ads alive, 5 pairs, 4 valves, largest 68 mm, most small. All with crisply distinct beak sculpture - most under the bridge span.

2001/144/ada, Lampsilis radiata (Eastern Lamp-Mussel) (Mollusca). 5+several adult, shell, specimen, seen. sev M & F alive, 2 pairs, 2 valves females, largest 91 mm, 88 mm male pair.

2001/144/adg, Lasmigona costata (Fluted Shell) (Mollusca). 2 adult, shell, specimen. 98 mm pair, 1 fragment.

2001/144/adh, Sphaerium simile (Mollusca). 4 shell, specimen. collected with Unionids.

2001/144/aaa, Rana clamitans (Green Frog) (herp). many adult, juvenile, call, seen, heard. many ad & new-trans juvs in weedy stream shallows, few calls.
2001/144/aab, Rana pipiens (Leopard Frog) (herp). many adult, juvenile, seen. ad & new-trans juvs jumping to shore from weedy shallows.
2001/144/aac, Rana catesbeiana (Bull Frog) (herp). several adult, juvenile, seen. ca 80 mm SVL ads in weedy shallows.

2001/144/aba, Castor canadensis (Beaver) (Mammal). present food, tracks. 2 3 cm-diameter Ash branches in stream above bridge. The stream above the bridge isn't impounded, though the pool under and below the bridge may be (we didn't go downstream of the bridge), and Beavers are clearly coming upstream of the bridge to forage.
2001/144/abb, Procyon lotor (Raccoon) (Mammal). present adult, juvenile, food, tracks. ad & juv tracks all over mud, tooth holes in Unionids. The riffle just upstream of the bridge was completely dry - no flow - and trampled by these 'coons, with broken-open pairs of Unionid shells, many with tooth holes, scattered around. There were lots of tracks elsewhere as well, but it was obvious that the 'coons had cleaned out the Unionids exposed by the drying of the riffle, as well as others along the shores of the pools where the water continues 50 cm deep.

2001/144/ac, Orconectes propinquus (Crayfish). several adult, under cover, captured, seen. und stones above bridge, too turbid to hunt properly.

2001/144/ae, cf Catostomidae (Sucker) (fish). 1 adult, skeleton, specimen. large Webberian apparatus.


Subject:[NatureList] Alasmigona marginata near the margins of Quebec
Date: Sun, 12 Aug 2001 00:35:24 -0400
To: Eastern Ontario Natural History List

Everyone,

After an EOBM programme at Fitzroy Park, Jennie and I did the trip-justifying poking around - at least I poked around, she sat in the car and read. This is an area where 3 streams with distinctive Unionid faunas - The Carp, the Mississippi, and the Madawaska, draining an area that extends from the outskirts of Ottawa to the heart of Algonquin Park, enter the Ottawa River in one 10 km stretch, so it's bound to be interesting, but until last month, I'd never been downstream of Hwy 17 on any of these rivers.

First we checked out Morris Island - a 14 sq km wooded peninsula between Fitzroy Harbour and the Mississippi, defined by the Mississippi Snye. The Snye proved, where the road crosses it, to be a tranquil marshy stream, popping with the common frog species, but unrelieved by any signs of Unionids, and made hazardous to the visitor by exceedingly steep slopes of crushed rock on the sides of the culvert causeway. Then we followed the road out to a point on the north of the island, where the shores of a shallow, quiet, gneiss-boulder bay of the Ottawa River were strewn with Muskrat or Beaver shell piles - small fast-grown shells of the typical Ottawa River mussel species - Elliptio complanata and Lampsilis radiata. Isabelle Picard and I fret about the species limits of our Lampsilis - 2, 3, 4, or 5 species? - and these will be a nice sample for studying shell shape and colour. But then, how does the shape and coloration of these shiny-new quick-growing small shells relate to the old, eroded, patternless shells that are the most perplexing to identify?

Then to the Mississippi River at Galetta. The Mississippi below Almonte has a marvelously diverse Unionid fauna, including Alasmidonta marginata, a species not yet recorded from Quebec (Isabelle Picard has since found it in Quebec streams - 29 Oct 2001). But above the dams at Almonte the fauna is reduced to the few commonest species, so I've long wondered if the diverse fauna is equally limited by the Hydro dam at Galetta, or if it persists in the 3 km of the Mississippi below this dam.

The dam at Galetta proved to be old and shabby looking, though the new signage of the Ontario Power Generation Corp proclaimed it to be a source of 'green' power (but how green can it be if it prevents the migration of fish that would transport the larvae of a regionally unique fauna of Unionids?). The emptied falls, bare limestone deeply grooved and scored by glacial ice, are east of the spillway, and the area below (on the west side) is a coarse cobble bottom, grading to boulders in the centre, 70-100cm deep at the shallowest crossing now, but obviously a metre or more deeper in a wet year. I waded across this, and then crossed a stoney bar into a silt-banked backwater on the east side, and circled this to where the glacially grooved limestone emerged on the shore above the Galetta Side Road bridge.

The cobble channel confirmed that the Mississippi fauna occurs downstream of the dam - living Lasmigona costata and their ruffled shells, large and juvenile, were common, and there were several heavy long dark Ligumia recta, huge quohog-like Lampsilis ovata, and shells, at least, of both Alasmidonta marginata and A. undulata.

The silty basin on the east side was something else altogether. There were few if any living clams, but immense numbers of old big dead shells, many still embedded in the bottom as if in life - when I reached for the first several of these I in fact thought they were alive, but they all proved to contain only mud. Cascades of smaller shells were eroding from the banks. I've never seen such a scene of in situ death of Unionids elsewhere in eastern Ontario - perhaps some change in flow, and increase in sediment load, sometime after the first dam was built here in 1824, smothered and buried an active mussel bed on this side of the stream, and an excavation of a few square metres in the centre might give us an idea of size and species composition of a pre-settlement mussel bed.

But in terms of living species, the big finding is that A. marginata is here, only 3 km from the Ottawa River at Lac des Chats, and only 6 km from the Quebec shore - so we may only have to search through an immense number of Elliptio and Lampsilis in muskrat piles on the Quebec side to find a few specimens that will add A. marginata to the Quebec list (Isabelle's compiling the first modern list of Quebec Molluscs, and it just doesn't seem right to have two species of Unionids known from the Ontario side of the Ottawa River, but not from the Quebec side). - fred. skip to contents


Subject:[NatureList] Zebra Mussels in the lowermost Mississippi
Date: Sun, 12 Aug 2001 19:54:44 -0400

"Frederick W. Schueler" wrote:

Then to the Mississippi River at Galetta... The dam at Galetta proved to be old and shabby looking, the area below is a coarse cobble bottom, grading to boulders in the centre, 70-100cm deep at the shallowest crossing now, but obviously a metre or more deeper in a wet year.

* while I was there, I met a fellow from Peterborough, related to local families, who told me that Zebra Mussels had been abundant there some years ago. I turned a fair number of rocks, but found neither Zebras nor Crayfish - only Goniobasis Horn Snails all over the rocks.

...but this morning I found one tiny (6mm) Zebra mussel on one of the Unionid shells I'd collected - so they are present at Galetta. I suppose there must be larvae coming down from Mississippi Lake all the way through the lower Mississippi (Pitsiuk Vachon gave me some small Zebra Mussels from the north shore of Mississippi Lake - the first year she's noticed them - and I've got to get out to her place and record their abundance). Does anyone know who's 'responsible for' Zebra Mussels at the Mississippi Valley Conservation Authority? - fred. skip to contents


Subject: [NatureList] Crayfish, drought, and Unionids in Kemptville Creek [south Branch of the Rideau River]
Date:Wed, 15 Aug 2001 22:47:44 -0400
To: Eastern Ontario Natural History List

Everyone,

The ecological interruptions dams impose on the ecology of streams is nowhere more clearly seen than in the changes in the reduction in the number of species of Unionid mussels above dams. In Kemptville Creek this is especially abrupt - since there are 7 species just below the dam in Oxford Mills, and only two species, Pyganodon grandis and Elliptio complanata, above it. But I'm always keen to check another stretch of the upstream creek for more species (where's Anodontoides ferrusacianus for goodness' sake?), and the current drought has nearly or completely emptied many streches of the creek.

So yesterday I went down to Bob Woolham's where the Diamond Road crosses the South Branch to look for freshly drought-exposed Unionids. I didn't find any - the remaining water was too weedy and murky to search effectively, and no predator has been leaving shells behind - but I did find Crayfish burrowed and barricaded under rocks on the dry creekbed. Our Crayfish, Orconectes virilis, isn't supposed to be a burrowing species, but in droughts they hole up under rocks, and are evidently prepared to spend weeks without any water.

I append my notes... I'd be interested in any other accounts of Crayfish under drought-exposed rocks (and any errors Bob catches in what I've written). - fred. skip to contents - skip to next


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Field notes of Frederick W. Schueler --- 14 August 2001
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Canada: Ontario: Grenville Co: Augusta: Kempville Crk@Diamond Rd. 31B/13, UTM 18TVE46 465 638 44.82760N 75.67638W. TIME: 1829-1947. AIR TEMP: circa 23C, sunny, calm. HABITAT: slow, nearly dry creek, creekside meadows, Ash forest, adjacent farms. OBSERVER: Frederick W. Schueler. 2001/155/a, visit. nat.hist., wade. The Creek here is as low as Bob Woolham has seen it - Some of the things he's noticed are: after a good Turtle nesting season he only sees 2 Painted Turtles in the persisting pools below the bridge - kids get Unionids out of deep (60 cm) hole above his Cattle crossing (which is dry now rather than usual 70 cm). Kingfishers doing really well with prey concentrated in isolated shallow pools. He's seen no Otters since last spring - There are few Coons and NO:Mephitis after MNR Raccon Rabies trapping but the few surviving Raccoons are execptionally destructive of Corn and captive Ducks. There are 2 Muskrats living in burrows near the bridge, but he doesn't see any fresh Unionid shells. I worked upstream from the bridge a bit beyond where the creek approaches Co Rd 18. The first stretch is 20 cm deep over bedrock, and dominated by with Hydrocharis morsus-ranae, murky and clotted with dark algae. Standing-up Nuphar leaves lines what are now the shores of muck.

The remaining water is swarming with little fish and the banks are writhing with hordes of unidentifiable Rana. Above the Nuphar is a dense stand of low white-flowered Polygonum below tall grass. There are no signs of recent Unionid mortality from the low water, and living ones would be hard to see in the murky water. Above an old crossing site the bottom is sandy mud over the bedrock - which crops out across the botom at one point. No water here, completely dry, and Oorconectes restricted to burrows under rocks - as recorded. All along there are scattered Bulimnaea, Lymnaea, Helisoma trivolvus shells, small Helisoma, Sphaerium, etc. shells in small depressions and patches on the bottom, and under stones, but no great numbers. Trees all green here - a scene of great tranquility as I leave, and to which the macro inverts, at least are well adapted.

I finished up at the bridge again - Rana pipiens suddenly identifiable, Crayfish carapaces doubtless Procyon prey under the bridge -

2001/155/ac, Orconectes virilis (Northern Crayfish) (Crayfish). 4+4+1 adult, prey of predator, captured, specimen. shells under bridge, prey of Procyon, 5 alive under dry stones. Four carapaces (38, 37, 38, 38 ca mm) and some chelipeds - doubtless Procyon prey - under the bridge. In the completely dry stretch of the creek, 5 (4 collected) were found in little burrows under flat rocks - just as Tom Cook found them in the North Branch in the droughts of the early 1980's. These were little chambers in the sandy mud of the dry creekbed.

1) in shallow burrow under 40 x 50 x 6 cm rock, ca 20 m from the nearest water.

2) Two Crayfish were together - one above the other - in an 8 cm deep burrow just under the edge of a 40 x 60 x 20 cm rock, with

3) another under a 20 x 25 x 3 cm rock just 15 cm away from these two

4) another (not collected), in a trilobed burrow, 5 cm deep, under a bigger flat rock. this is clearly walled off by a 25 mm wall of disturbed sandy mud.

...colour of all these dark and shiny (from an anoxic bacterial layer?), captives held alive for AKS to select for painting.

2001/155/ad, Circus cyaneus (Northern Harrier) (Bird). 1 adult, drive. F-plumaged, flew overhead.

2001/155/ae, Rana pipiens (Leopard Frog) (herp). 4 adult, seen. 1st identifiable at 1937 hr, ca 80 mm SVL ads near bridge. These were the first Rana seen during the visit that could be identified - an astonishing circumstance considering that the vegetation on the banks were writhing, and the weedy water churned, with hordes of unidentifiable Rana (doubtless including all four species that would be expected). All of a sudden (just at the time when Ardea showed up), these four adult Rana pipiens were quite out in the open. The number of frogs was as astonishing as their ability to keep hidden enough to evade identification - stands of Grass or Polygonum rustled and shook as I passed, and while there weren't as many in the water, there were quite a few. I saw few Insects around or under rocks, which isn't surprising considering the number of Frogs.

2001/155/afa, Procyon lotor (Raccoon) (Mammal). present adult, food, tracks. sparse tracks in mud along creek, 4 Orconectes carapaces are presumeably prey.
2001/155/afb, Odocoileus virginianus (Whitetail Deer) (Mammal). present adult, tracks. sparse tracks in mud along creek.

2001/155/ag, Pyganodon grandis (Common Floater) (Mollusca). 1+1 adult, shell, specimen, captured. 106 mm pair und.bridge, ca 120 mm ad alive in 20 cm water above bridge.

2001/155/ah, Elliptio complanata (Eastern Elliptio) (Mollusca). 4 adult, shell, captured. old rotten-shell pairs, 94, 85, 74, 77 mm, not saved.
2001/155/ai, Bulimnea megasoma (Showy Pond Snail) (Mollusca). 3+ adult, shell, captured. shells scattered on bottom, 1 alive und.bridge, largest 46 mm. Not saved.
2001/155/aj, Lymnaea stagnalis (Great Pond Snail) (Mollusca). 3+ adult, shell, captured. shells scattered on bottom, largest 53 mm of 3 picked up. Not saved.

2001/155/ak, Helisoma trivolvus (Larger Eastern Ramshorn) (Mollusca). 3+ adult,shell, captured. shells scattered on bottom, 45 mm picked up. Not saved.
2001/155/al, Sphaerium simile (Striated Fingernail Clam) (Mollusca). 3+ adult,shell, captured. shells scattered on bottom, 18 mm picked up. Not saved.

(same location) TIME: 1937. AIR TEMP: 20, clear, calm, sunset. 2001/155/am, Ardea herodias (Great Blue Heron) (Bird). 1 adult, seen, heard. in nearly-dry creek.


Subject: [NatureList] More Kemptville Creek Mussel News
Date: Fri, 31 Aug 2001 22:14:07 -0400
To: Eastern Ontario Natural History List

Everyone,

Where the Patterson Corners Rd crosses Kemptville Creek, the bottom is a mosaic of nearly abutting limestone slabs - one of the natural wonders of the area, and a site it always refreshes me to visit (as one of the natural wonders of the area, it is of course conspicuously absent from the local tourism literature, which seems to assume that the spirit of visitors will be maximally refreshed by the messages - "We're selling stuff here, too," or "People have been selling stuff here for 210 years.") I've never set out to systematically turn a lot of the rocks in this slab-field to see what rare snails or Insects might be living beneath them, but I do know it's a good place to find predator-opened Unionid shells during a drought.

...and so it turned out today - a second site in a week for the third species of Unionid I've found above the dam at Oxford Mills - Lasmigona compressa, the Brook Lasmigona, a clam of understated elegance and headwaters distribution, which seems to be most frequently encountered right in the shadow of bridge spans. I suppose the fact that I've just started to find them means that they live tucked in deep among rocks, and the Coons were only able to reach them during the drought - and down among rocks they wouldn't be evident to a human observer. skip to contents - skip to next


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Field notes of Frederick W. Schueler --- 31 August 2001
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Canada: Ontario: Grenville Co: Oxford-on-Rideau: Kemptville Crk@Patterson Corners Rd Bridge. 31B/13, UTM 18TVE47 463 771 44.94730N 75.68032W. TIME: 1745-1909. AIR TEMP: 21.5, light overcast, Beaufort light air. HABITAT: shallow flat-slab riffle in brown-water creek/deciduous forest. OBSERVER: Frederick W. Schueler. 2001/164/ca, Lasmigona compressa (Brook Lasmigona) (Mollusca). 1 shell, prey of predator, specimen. broken shell near bridge.

2001/164/cb, Elliptio complanata (Eastern Elliptio) (Mollusca). many shell, prey of predator, specimen. opened shells from slabfield, few seen alive. I gathered all the fresh Unionid shells in my path in wandering around the slabfield to the open water above and below the bridge. A few of this species were alive on the shore and the extreme shallows.

The water level is down below the tops of the field of grooved slabs of limestone that crosses the creek both above and below the bridge - there's a pool under the bridge, perhaps due to damming by fill resulting from the bridge. These slabs are spaced about 5-15 cm apart, and the little water that is flowing runs around and among them in trickles. The higher slabs above the bridge are swathed in a whiteish-grey blanket of dried (cf Cladophora) algae. Predators have been active here, but one imagines that most of the Unionids and other macroinverebrates are safe beneath the slabs. No rock that I turned on the shore showed signs of Crayfish burrows beneath it, but I didn't turn many rocks in the water.

Pyganodon grandis (Common Floater) (Mollusca). many shell, prey of predator, specimen. opened shells from slabfield, most broken. Because these shells were so often broken they may be under-represented in the sample.

2001/164/cd, Bulimnea megasoma (Showy Pond Snail) (Mollusca). few shell,

prey of predator, specimen. dead shells -.

TIME: 1758. AIR TEMP: 21.5, light overcast, Beaufort light air. 2001/164/ce, Hyla versicolor (Tetraploid Gray Treefrog) (herp). 1 call, heard. single burst of hesitant calling.


Subject: [NatureList] circum- navigation & perambulation around Glen Isle

Everyone,

This is an account of Bev Wigney and me paddling, lining, and carrying her canoe around Glen Isle in the Mississippi River below Carleton Place. There's plenty of introductory material in the first records, that you can choose to read only that, or go on to the full account of the trip. Bev has posted a slideshow of her photographs from this trip - I've included direct links to the .jpgs in my accounts, but they may malfunction as the Yahoo server sometimes knocks out direct links made to images. If you want to (fairly reliably) access the photos, this link to the slideshow should always be the most dependable.

My interest in pre-settlement sub-fossil Unionid shells is from the hope of finding some of the species that now occur only downstream of the dams in Almonte (Ligumia recta, Alasmidonta marginata, Alasmidonta undulata, & Strophitus undulatus) on the hypothesis that these species are kept out of the upper river by restrictions on the movement of their fish hosts.

Our conclusions about what's distinctive about this stretch of the Mississippi:

1) Dreissena is present but not yet in big numbers - only about 1/sq m or less under the rocks turned - we'll have to wait to see how this turns out - whether an equilibrium like that at Andrewsville on the Rideau - a few Zebras present, but no great numbers - is established or whether Mississippi Lake becomes an overwhelming source of veliger larvae, paving the Mississippi over with Zebras.

2) Lasmigona costata is present in good numbers - the first concentration of shells (i.e. population) known from the upper Mississippi. The other species are the characteristic upper Mississippi forms - though the two big Pyganodon shells may represent a second species (e.g. actual P. grandis ) distinct from the dwarfed ones.

3) Native Orconectes Crayfish and Viviparus Mystery Snails are in place - so none of their congeneric invasives have arrived. We found NO:Necturus, so if they're here, they must be under stones different from the ones we turned.

4) The bottom alternates between two types - bedrock and Vallisineria/Viviparus on mud - though in places the mud is still tempered by a substantial amount of sawdust, and in places scattered or piled rotten slabwood, decades (how many?) since such dumping must have ceased (since writing this, I've realized that perhaps the only way to find pre-settlement subfossil Unionids will be to dig in the these fetid beds of rotten sawdust around the shores of Glen Isle - 29 Oct 2001).

5) The bedrock flats, where they include ultra-thin corroded-away slabs of limestone, are a distinctive habitat - remarkable for the frequency of Hellgrammites, the clustered Caddis tubes, and the little dark Physa beneath them. This fauna should be inventoried before Dreissena completely takes over.

6) The shores, where not cottaged, are dense Soft Maple-dominated forest, right down to the water's edge, though Salix nigra takes up some of the actual shoreline. The shore is also riddled with Castor tunnels. Floating patches of Vallisineria and edge-bitten Unionid shells suggest off-shore feeding, while felled Maple trees suggest an incentive for this.

7) The soil these forests grow on is shallow over the flat bedrock, and there's no signs of pre-settlement sub-fossil Unionids. skip to contents - skip to next


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Field notes of Frederick W. Schueler --- 18 September 2001
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(at home) TIME: 1005. AIR TEMP: 16.5, light rain, calm. ROUTE: DHR, Hwy 7. OBSERVER: Frederick W. Schueler, Bev Wigney. 2001/184, departure . nat.hist., drive. in Bev's Car to Carleton Place. Bev wrote:

My usual trips are to put in somewhere, travel upstream and then return downstream to my truck. I'm assuming that we're taking my canoe, but would you rather take your truck and canoe? This canoe is very light in weight (a Carbonlite), but also tends to be a bit sensitive..as in tippy-feeling...

* The best thing to do might be to put in at the Glen Isle bridge, and then circum-navigate the island, with excursions up and downstream in the main channel. If we can't get up the downstream side of the west channel (marked with a lot of rapids [now doubtless riffles] on the map) we could walk back to get the truck on the road across the island. It would seem a pity to drive a second vehicle all that way just in order to shuttle 5 km, when we could come back to the launch site or only walk a couple of km. We'll look at the map before we leave. As far as choice of vessel goes, we want minimum draft, but if yours is narrower than ours and draws a little more water it will be lighter to carry, line, or whatever. I don't think stability is likely to be a concern - I imagine most of the clamming will be done while wading or on shore - if we find subfossils we'll be digging them out of the bank.

I can probably be down your way as early as you like so don't hesitate to say 7 or 8 or whatever. I'm not actually too worried about the water depth around my friend's place, but I'll ask him today. His wife has a small rowboat which she rows up and down through that section of river catching fish, so I suspect it's not that bad most of the time.. just not really a place that motor boats can get into without doing some damage on random large rocks. Also, I'm not too worried about scratching the bottom of this canoe as it rides high..but never loaded it down with clams before, so we'll see...

Canada: Ontario: Lanark Co: Beckwith: Mississippi R/1.5 km SW Glen Isle bridge. 31F/1, UTM 18TVF 103.8 0.4 45.15011N 76.13969W. TIME: 1115-1136. AIR TEMP: 18 ca, overcast, calm. HABITAT: Acer/Populus/Salix trampled river shore@parking area & bridge, clearwater river. 2001/184/a, Onoclea sensibilis (Sensitive Fern) (p). codominant herb, dead, seen. WAYPT/079, crisp and dead among shore shrubs near parking area. We launched and left the truck here, planning to go down the Mississippi and circum-navigate Glen Isle, after paddling a couple of 100 m upstream towards Carleton Place. We're looking for Unionids, sub-fossil Unionids that might antedate the Almonte dams, Crayfish to see if Orconectes rusticus might be here, and to search for Dreissena. At the bridge the scattered old broken shells on shore were
LIST:
Elliptio complanata, most frequent;
Lampsilis, typical small Upper Mississippi siliquoidea-like shells;
Pyganodon, a few small Lake Nipissing-like shells.

As we went downstream from the bridge we had our first experience of the stretches of bare flat bedrock that we would be paddling and lining over all day, and then into an area of flat water with a Castor lodge and 2 'basking' Chrysemys picta.

moved 0.5 km ENE.

Mississippi R/1.1 km SSW Glen Isle bridge. UTM 18TVF 108.1 2.3 45.15187N 76.13427W. TIME: 1156-1250. AIR TEMP: 18 ca, overcast, calm. HABITAT: clearwater river, limestone bedrock shallows, water 17.5 C, Acer/Populus/Salix shores. 2001/184/ba, Elliptio complanata (Eastern Elliptio) (Mollusca). 2 adult, under cover, photo. WAYPT/080, small ads und rock, photographed. Bev's photo of the typical upper Mississippi Unionids (left to right) Lampsilis radiata, Elliptio complanata, and Pyganodon sp.

(same location) TIME: 1156-1250. 2001/184/bb, Lampsilis radiata (Eastern Lamp-Mussel) (Mollusca). 3 adult, under cover, photo. small ads und rock, photographed.

(same location) TIME: 1156-1250. 2001/184/bg, Pyganodon grandis (Common Floater) (Mollusca). 3+1 shell, adult, prey of predator, under cover, photo, specimen. small.ad und rock, 2 predator-broken, perforate ad, largest 62 mm. The shells were on the roots of a big Acer saccharinum at the water's edge, and the adult with the perforate shell (collected) was in 15 cm water nearby.

(same location) TIME: 1156-1250. 2001/184/bc, Orconectes virilis (Northern Crayfish) (Crayfish). 4 dead, adult, female, under cover, photo. 1 ad F fd dead, 3 small adult F alive und rocks. This is an incredible habitat - hectares of flat limestone with 10-30 cm of water flowing over it at about 1 m/sec, and scattered 30-80 cm pitted slabs of very thin limestone that has obviously weathered in place, most 2-3 cm thick, and some only 1 cm thick, with holes in them through which the water bubbles when the slab is turned up on edge. (Bev's photo of me and the canoe on shore in the area where the thin sheets of limestone were found ). There are a few old rounded slabwood pieces on the bottom as well. Not many Crayfish under the rocks - the most conspicuous life is masses of Caddis tubes, made of coarse grains of sand, welded to the undersides of the slabs. Bev's photos of Orconectes virilis in water at edge of a stone, dorsal view, and ventral view of a female.

(same location) TIME: 1156-1250. 2001/184/bd, Orconectes propinquus (Crayfish). 1 adult, female, under cover, photo. 1 ad F und thin slab.

(same location) TIME: 1156-1250. 2001/184/be, Corydalus cornutus (Dobsonfly) (entomological). 6 larva, under cover, photo. und thin slabs, 5 ca 70 mm TL, 1 ca 40 mm TL. We spent almost an hour here, turning the thin slabs, and Bev photographing the animals we found - especially this species: "This is probably the best photo of it, but still not great. There might have been some that would have been better, but its head was always under the algae pieces. The ones that I took of it swimming around in the orange bucket look like something out of a cheap sci-fi flick."

(same location) TIME: 1156-1250. 2001/184/bf, Dreissena polymorpha (Zebra Mussel) (Mollusca). 5 adult, under cover, specimen. und thin slabs, largest 16 mm, boldly striped. Most slabs did not shelter any of these, which are all we found in the almost an hour we spent turning rocks.

(same location) TIME: 1156-1250. 2001/184/bh, Viviparus georgianus (Banded Mystery Snail) (Mollusca). 1/common adult, shell, under cover, specimen. fairly common und thin slabs, 1 shell preserved. The other Gastropods under the slabs were small dark Physa.

(same location) TIME: 1156-1250. 2001/184/bi, Ameiurus nebulosus (Brown Bullhead) (fish). many juvenile, under cover, seen, photo. und thin slabs, 4-8 cm TL. There were often 4-12 of these under a single slab.

Mississippi R, abv Arklan Rapids, 1.4 km SSW Glen I.bridge. UTM 18TVE 109.8 998.5 45.14853N 76.13207W. TIME: 1310. AIR TEMP: 18, overcast, breezy. HABITAT: clearwater river, limestone bedrock shallows, water 17.5 C, Acer/Populus/Salix shores. 2001/184/ca, Orconectes virilis (Northern Crayfish) (Crayfish). 1 adult, male, under cover, seen, photo. WAYPT/081, und 70 x 80 x 5 cm slab, large pink & blue ad.

(same location) TIME: 1310. 2001/184/cb, Orconectes propinquus (Crayfish). 5-6 juvenile, under cover, seen. und 70 x 80 x 5 cm slab.

(same location) TIME: 1310. 2001/184/cc, Pyganodon grandis (Common Floater) (Mollusca). 1 shell, under cover, specimen. und 70 x 80 x 5 cm slab, compact 55 mm Nipissing-like pair.

(same location) TIME: 1310. 2001/184/cd, Dreissena polymorpha (Zebra Mussel) (Mollusca). 3 shell, under cover, specimen. und 70 x 80 x 5 cm slab, largest 16 mm, boldly striped. On the basis of this rock, then, there are 1.7 Dreissena/square metre.

(same location) TIME: 1310. 2001/184/ce, Hyla versicolor (Tetraploid Gray Treefrog) (herp). 1 call, heard. calling briefly. From here we lined the canoe down the rapids past the still standing masonry wall of the old mill sluice - it might have been easier in the millrace itself, and then down to the calm water SE of Arklan Island.

we moved 0.3 km E - past the sluiceway between Arklan Island and mainland shore, and the mill ruins on Arklan Island at the lower end of sluiceway.

Arklan Island/1.3 km S Glen Isle bridge. UTM 18TVE 112.7 998.6 45.14859N 76.12836W. TIME: 1345. AIR TEMP: 18, overcast, breezy. HABITAT: mossy seepage or spring in flat limestone alg Mississippi R. 2001/184/da, (p). dominant herb, specimen. WAYPT/082, in seepage. NO:Eurycea under rocks turned.

(same location) TIME: 1345. 2001/184/db, Nasturtium officinale (Water Cress) (p). codominant herb, in bloom, forage. clumps along flow into river. On the wide stretches of flat bedrock here, there are few Unionids in the river, and no shells on the shore.

Mississippi R/.9 km SSE Glen Isle bridge. UTM 18TVF 116.7 3.4 45.15301N 76.12332W. TIME: 1410. AIR TEMP: 18, overcast, breezy. HABITAT: clearwater river, sawdust shore, Acer/Populus/Salix forest. 2001/185/aa, Elliptio complanata (Eastern Elliptio) (Mollusca). many shell, prey of predator, specimen, Muskrat shell pile. WAYPT/083, many fresh shells und roots of Acer, largest 93 mm. This was a spreading root canopy with several square metres of sheltered space - and shells under quite a wide area. The shore is all rotten sawdust, to a depth of about 70 cm in places - with pieces of slabwood embedded in it.

(same location) TIME: 1410. 2001/185/ab, Lampsilis radiata (Eastern Lamp-Mussel) (Mollusca). 9 shell, prey of predator, specimen, Muskrat shell pile. und roots of Acer, 6 valves, 3 pairs, largest 70 mm.

(same location) TIME: 1410. 2001/185/ac, Pyganodon grandis (Common Floater) (Mollusca). 2 shell, prey of predator, specimen, Muskrat shell pile. und roots of Acer, large fragmentary valves.

(same location) TIME: 1410. 2001/185/ad, Rana clamitans (Green Frog) (herp). many juvenile, seen, heard. many along shore but hard to identify. All that were seen clearly were this species.

(same location) TIME: 1410. 2001/185/ae, Pseudacris crucifer (Spring Peeper) (herp). 1 call, heard. calling briefly, alternating with a Bird. Once again, strikingly few of this species are heard.

(same location) TIME: 1410/1745. AIR TEMP: 18, overcast, breezy. 2001/185/am, Pandion haliaetus (Osprey) (Bird). 1 adult, seen, heard. flying between trees here both on our way out & back.

moved 1.0 km E.

Glen Isle, Mississippi R/1.5 km ESE Glen Isle bridge. UTM 18TVF 126.9 5.2 45.15474N 76.11035W. TIME: 1450. AIR TEMP: 18, overcast, breezy. HABITAT: 1 m deep Vallisineria/Castor dominated stretch of river. 2001/185/ba, Vallisineria americana (Water-celery) (p). dominant herb, prey of predator, seen. WAYPT/084 & 085, covers most of bottom, patches of cut plants. ...floating on surface, as if a by-product of Beaver(?) herbivory. There are lots of Ceryle alceon along the river here, and Wolffia drifted against the shore - the predominant floating duckweed.

(same location) TIME: 1450. 2001/185/bb, Viviparus georgianus (Banded Mystery Snail) (Mollusca). dominant herb, prey of predator, seen. all over the bottom whereever it's clear >50/sq metre.

(same location) TIME: 1450. HABITAT: rocky bar, on shore of 1 m Vallisineria/Castor dominated stretch of river. 2001/185/bc, Elliptio complanata (Eastern Elliptio) (Mollusca). 20 shell, prey of predator, Muskrat shell pile, specimen. crunched & littered rock bar, 14 pairs, 6 valves, largest 85 mm. We landed on this bar of rock jutting out from the Glen Isle shore - after a run across 1 m depth Vallisineria flats - and found lots of these crunched & littered on the bedrock bar. There are Castor cut trees in the woods behind, and a Beaver swam out from the shore vegetation and under the canoe soon after we left here.

(same location) TIME: 1450. 2001/185/bd, Rana clamitans (Green Frog).. many juvenile, seen, many juvs on shore.

(same location) TIME: 1450. HABITAT: 1 m deep Vallisineria/Castor dominated stretch of river. 2001/185/be, Pyganodon grandis (Common Floater). 1 shell, specimen, big pair, in 1 m water among Vallisineria. About 100m downstream fr waypoint.

moved 1.0 km N.

Mississippi R/1.4 km ENE Glen Isle bridge. UTM 18TVF 126.6 15.3 45.16385N 76.11101W. TIME: 1527. AIR TEMP: 18 ca, overcast, breezy. HABITAT: Sparganium/Scirpus/Pontederia deepwater clay river shore, Salix along bank. 2001/185/ca, Lasmigona costata (Fluted Shell) (Mollusca). 3 shell, prey of predator, shell pile, specimen. WAYPT/086, old pair, 2 valves, largest 85 mm, among many Elliptio.

(same location) TIME: 1527. 2001/185/cb, Elliptio complanata (Eastern Elliptio) (Mollusca). many shell, prey of predator, shell pile, seen. predominant species in old Castor(?) shell pile.

(same location) TIME: 1527. 2001/185/cc, Pyganodon grandis (Common Floater) (Mollusca). 1 shell, prey of predator, shell pile, seen. old pair among many Elliptio, not saved.

(same location) TIME: 1527. 2001/185/cd, Aix sponsa (Wood Duck) (Bird). 2 pair, seen, heard. flew off.

(same location) TIME: 1527. 2001/185/ce, Rana catesbeiana (Bull Frog) (herp). 1+several pair, seen. 115 mm SVL F dead on shore, several jumped in. This carcase was sort of crusty and half-dry - it looked like it had been dead for a week. As usual it was hard to determine the jump-in frogs, but several were clearly this species.

(same location) TIME: 1527. 2001/185/cf, Castor canadensis (Beaver) (Mammal). present adult, tracks. burrows, peeled sticks, and trails conspicuous. Obviously there are a lot of bank-dwelling Castor here, and the Unionids are bitten around the edges in the way I associate with Beaver predation.

Mississippi R/.8 km NNE Glen Isle bridge. MAP:31F/1, UTM 18TVF 116.3 022. TIME: 1626. AIR TEMP: 18 ca, overcast, breezy HABITAT: marshy stretch of clearwater shallow river FWS0109181626/a, Decodon verticillatus (Swamp Loosestrife). dominant shrub, seen. pink-foliaged colonies in little round midstream islands. Bev's photo of a stand of Decodon verticillatus, and the roots growing from the stems into the water. The roots of these were very pink, and Bev finds (11 Oct) that this seems to be unusual since she's been checking the root systems of other colonies of these while out paddling and hasn't encountered any with the same brilliant colouring. Is this is related to water pH levels or something like that (similar to the colouring in hydrangeas for example).

Mississippi R/.8 km NNE Glen Isle bridge. UTM 18TVF 114.9 19.9 45.16784N 76.12594W. TIME: 1638-39. AIR TEMP: 18 ca, overcast, breezy. HABITAT: clearwater river shallows of jagged limestone bedrock. 2001/185/da, Lampsilis radiata (Eastern Lamp-Mussel) (Mollusca). 9 adult, shell, specimen. WAYPT/087, 3 taken alive, 1 fresh, 5 old pairs, largest 65 mm. The bottom here, on the sill between two strecthes of flat water behind Glen Isle, is corroded into incredibly jagged and sharp points along closely spaced joints in the rock - and these clams live in the depressions. Needless to say, we had to carry the canoe over the shallowest of the sill.

(same location) TIME: 1638-39. 2001/185/db, Elliptio complanata (Eastern Elliptio) (Mollusca). 3 adult, shell, specimen. 2 taken alive, 1 old pair, largest 95 mm.

(same location) TIME: 1638-39. 2001/185/dc, Viviparus georgianus (Banded Mystery Snail) (Mollusca). many adult, shell, specimen. fairly common.

moved 0.4 km SSE.

Mississippi R/.6 km NNE Glen Isle bridge. UTM 18TVF 115.9 16.6 45.16483N 76.12459W. TIME: 1659. AIR TEMP: 18 ca, light overcast. HABITAT: clearwater river, very flat bedrock shallows & riffles/wooded shores. 2001/186/aa, Lampsilis radiata (Eastern Lamp-Mussel) (Mollusca). common adult, seen. WAYPT/088, scattered on bedrock in shallows. We pulled the canoe along this stretch, which is strikingly flat, with dense woods on each shore.

(same location) TIME: 1659. 2001/186/ab, Elliptio complanata (Eastern Elliptio) (Mollusca). common adult, seen. under rocks in shallows.

(same location) TIME: 1659. 2001/186/ac, Orconectes virilis (Northern Crayfish) (Crayfish). 1 adult, seen. under rock in shallows.

moved 0.6 km SSW.

Glen Isle bridge, Mississippi R. UTM 18TVF 112.9 11.7 45.16046N 76.12831W. TIME: 1659. AIR TEMP: 18 ca, light overcast. HABITAT: bedrock river riffles@bridge. 2001/186/ba, Pyganodon grandis (Common Floater) (Mollusca). 1 shell, specimen. WAYPT/088, picked up as we lined the canoe along.

(same location) TIME: 1659. 2001/186/bb, Orconectes propinquus (Crayfish). 1 dead, male, adult, specimen. dead M picked up as we lined the canoe along.

(same location) TIME: 1659. 2001/186/bc, Butorides striatus (Green Heron) (Bird). 1 adult, seen, heard. flew overhead.

(same location) TIME: 1659. 2001/186/bd, Ardea herodias (Great Blue Heron) (Bird). 1 juvenile, seen. perched on branch over stream, very unafraid of us. This was on a Salix branch that extended out from the shore, and it was strikingly clear-cut in appearance as it calmly watched us go past. Had we taken a photograph it would have been striking even among the many striking images of this species. The fluffy plumage seemed to indicate a hatching-year bird.

moved 0.2 km S.

Mississippi R/.2 km S Glen Isle bridge. UTM 18TVF 112.6 9.4 45.15838N 76.12871W. TIME: 1731. AIR TEMP: 18 ca, light overcast. HABITAT: Rhamnus cathartica-dominated woods@head of shallow bedrock riffles. 2001/186/caa, Castor canadensis (Beaver) (Mammal). present adult, food, tracks. WAYPT/089, very active, felling Elms in riverside woods.

(same location) TIME: 1731. HABITAT: head of shallow bedrock riffles blw bedrock & marshy reach. 2001/186/cab, Gyrinidae (Whirligig Beetle) (entomological). 1000 s mature, seen, active. covering the river from shore to shore above the riffle.

(same location) TIME: 1731. 2001/186/cb, Elliptio complanata (Eastern Elliptio) (Mollusca). 1 shell, specimen. 99 mm pair.

(same location) TIME: 1731. 2001/186/cc, Lampsilis radiata (Eastern Lamp-Mussel) (Mollusca). 6 shell, specimen. 4 pairs, 2 valves, largest 62.5 mm.

(same location) TIME: 1731. 2001/186/cd, Viviparus georgianus (Banded Mystery Snail) (Mollusca). many shell, specimen. many old shells. A handful of gravel and shells from the bottom, to preserve a record, however scrappy, of the pre-Dreissena fauna. Sample needs to be sorted.

moved 0.9 km SSE.

Canada: Ontario: Grenville Co: Mississippi R, 1.1 km SSE Glen Isle bridge. UTM 18TVF 115 0.4 45.15032N 76.12545W. TIME: 1804-1830. AIR TEMP: 17, cloudy, calm. HABITAT: shallow bedrock river/cottagy shore. OBSERVER: Frederick W. Schueler. 2001/186/d, Unionidae (Unionid Mussel) (Mollusca). shell, specimen. WAYPT/090, many more shells than previous 15 yr. We pulled in here, where friends of Bev's were doing some yard work, after pulling through some soupily dense marshes where the channels diverge around Glen Isle. This is the lowest water levels the residents, Frank and Jane Yam, can recall, and they've noted the large number of shells below their low retaining wall and dock. NO:Dreissena noted.

(same location) TIME: 1804-1830. 2001/186/da, Pyganodon grandis (Common Floater) (Mollusca). 1 shell, specimen. low-beaked, ripply scupture, 76 mm fresh valve.

(same location) TIME: 1804-1830. 2001/186/db, Lasmigona costata (Fluted Shell) (Mollusca). 5 shell, specimen. 3 freshvalves, 2 not-fresh pairs, largest 86.5 mm.

(same location) TIME: 1804-1830. 2001/186/dc, Lampsilis radiata (Eastern Lamp-Mussel) (Mollusca). 15 shell, specimen. 11 pair, 4 valves, largest 64.5 mm, fairly fresh, almost all rayless.

(same location) TIME: 1804-1830. 2001/186/dd, Elliptio complanata (Eastern Elliptio) (Mollusca). 15 shell, specimen. 10 pairs, 5 valves, largest 95.5 mm, fairly fresh.

(same location) TIME: 1804-1830. HABITAT: cottagy shore of shallow bedrock river. 2001/186/e, Branta canadensis (Canada Goose) (Bird). 100 ca adult, flock, seen, heard. overhead.


Subject: [NatureList] Re: South Nation at Ventnor & Indian Creek at the Limerick Forest Access Road
Date: Fri, 21 Sep 2001 21:18:27 -0400
To: Eastern Ontario Natural History List

"Frederick W. Schueler" wrote:

> bev wrote:
Re: the South Nation around Ventnor- I have never paddled there, I take it that you meant as a place for a future trip, in which case I would say, sure... why not?.. it's worth a try.

* first I'm thinking about just checking for clams around the bridge, which I think I'll do tomorrow. Naomi indicated that there wasn't much flow, so paddling might be more a matter of dragging the canoe, which would be less fun in South Nation clay than it was over Mississippi limestone.

Well that just shows how little I knew. There's no clay in the South Nation at Ventnor, which is just downstream from Spencerville, but there's lots of limestone, and with enough water to float a canoe you'd have a whitewater event rather than clamming. The South Nation there now consists of a vast flat expanse of damp limestone, blanketed in diverse algae and aquatic moss, and dotted with the yellow flowers of little dwarfed(?) Bidens plants. There are scattered stones and bars of stones, but the extensive substrate is bedrock. For the whole extent of the village (ca 400m) the stream consists of one long riffle, which is barely dampened by a trickle of flow. I worked upstream from the present bridge to old bridge abutments, doing my usual superficial evalauation of the site: Amphibians, reptiles, clams, and crawdads.

A bunch of kids told me there were big Crayfish in the 35cm deep water under the bridge (this represented the deepest water in the whole riffle), but the dusting of fine algal/detrital muck on the bottom made it impossible to turn stones and see what had been under them. Something hard bumped into my hand as I turned one, but I didn't see any Crayfish. Nor were there any clams or shells, and most of the frogs were just unidentifiable swirls and jumps.

But I kept going upstream, "just a little bit further," and after a while it began to be interesting to see how far this interminable riffle would extend. Then a scattering of freshly opened Unionid shells began to relieve the tedium, and by the time I reached the head of the riffle at the old bridge (shown as functional on the topo map, but obviously removed long ago) I'd found Elliptio complanata (vastly predominant), Pyganodon grandis, Lasmigona compressa, Strophitus undulatus, Lampsilis radiata, and Anodontoides ferrusacianus. Most of the shells were pulled up on shore and opened by predators during the current low water. I saw Raccoon tracks, but not a lot of sign of Muskrats.

I saw one juvenile Crayfish under a stone (Orconectes virilis), despite turning about 30 stones on my way up the riffle - but most of the water was 'new water' so it's hard to say whence the crayfish may have retreated when the water was the lowest, or how fast one would expect them to reoccupy the entire riffle. Above the sill at the head of the riffle there's placid water seething (when disturbed) with aquatic Rana, likely mostly Bull Frogs. About 100m below the present bridge the water becomes deeper and still, but I didn't check that area.

Then on the way home, I stopped at Indian Creek where it crosses the Limerick Forest Access Road, north of Roebuck. I've often wondered if any Unionids lived this far upstream, where the creek flows from a brushy area into a Cattle pasture beside a Corn field, and since the stream was completely dry, except for a shallow green-algal pool on the bedrock right below the culverts, I stopped to check it out.

Sure enough there were a few big (150mm) fragmentary Pyganodon grandis shells below the culverts, so I scooped them up into my trusty popcorn bag, and then ducked under the barbed wire that keeps the Cattle on their side of the road, and went under the road and upstream. The bed of the creek is completely dry - scattered stones on limestone bedrock, with a rusty-chestnut coating of algae over everything, contrasting with the green of the grass and shrubs. But there were scattered not-fresh Pyganodon shells every few metres, so I was decoyed farther and farther upstream. None of the shells were fresh, and most looked like they had died in the 1999 drought. But then there was a Lasmigona costata shell among the Pyganodon (by now the bottom was sandy mud rather than bedrock), and soon a damp place where the Pyganodon were freshly opened among Raccoon tracks. So I continued upstream, and then found first an old, and then a fresh, Elliptio complanata shell. Big, compressed, purple, heavy-shelled specimens, similar in some ways to what Isabelle is calling Elliptio cf crassidens from the Ottawa River & St Lawrence.

About 100m farther, as the creek twisted up towards Co Rd 18 (I could hear the traffic, and it sounded pretty close-by), there was actual water, again seething with Frogs, and with lots of freshly opened shells on the margins. But one presumes that some adult mussels must survive in the water, and that if we ever have a series of wet years again the creek will be repopulated. By the time I was coming back the 7 L popcorn bag was overflowing with shells. So here's a nearly dry no-flow creek only about 2-3m wide, only a km or so from its source in a wetland, with three big Unionids in it, and one of the species really abundant. No Crayfish under the few stones I turned.

At both of these sites Hawthorns were fruiting prolifically right along the stream edge (ours at home on the limestone plain don't have any fruit at all), and Sphaerium Figernail Clam shells were scattered on the dry stream bed like sprinkles on a cake, and I obtained a sample of Snail shells that had been swept up by the higher water after one of the recent rains. - fred. skip to contents


Subject: [NatureList] South Nation 3 Oct(I): Casselman High Falls

Everyone,

I suppose that it's because I was brought up on granitic & metamorphic terrain, but vast expanses of limestone bedrock always excite me - and I accordingly consider the High Falls of the South Nation one of the great natural spectacles of Eastern Ontario. Here are the field notes from a visit there, finding that Zebra Mussels haven't increased much since last year. Bev has posted her photos from the whole 3 October trip as a slideshow - I've included direct links to the .jpgs in my accounts, but they may malfunction as the Yahoo server sometimes knocks out direct links made to images. If you want to (fairly reliably) access the photos, this link to the slideshow should always be the most dependable. - fred. skip to contents - skip to next


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Field notes of Frederick W. Schueler --- 3 October 2001.
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(at home) TIME: 1128. AIR TEMP: 19, cloudy, breezy. OBSERVER: Frederick W. Schueler. hondalog, departure . nat.hist., drive. 239057.7 km, to Bev Wigneys, Osgoode, and South Nation River for clams. Clearing after an overcast drizzly morning.

moved 4.7 km N.

Co Rd 18, 1.4 km SSE Hutchins Corner. UTM 18TVE46 453 733 44.91302N 75.69259W. TIME: 1135. AIR TEMP: 19 ca, cloudy, breezy. HABITAT: small marshy creek, pastures. 2001/193/g, Rana pipiens (Leopard Frog) (herp). 100 s adult, DOR, drive. DOR grease-spots from last night's movement.

Canada: Ontario: Prescott & Russell Co: Cambridge: High Falls, above lower dam, South Nation R, Casselman. 31G/6, UTM 18TVF 926.7 182.7 45.31990N 75.09314W. TIME: 1318. AIR TEMP: 22, sunny, windy. HABITAT: 40 cm bedrock river shallows between old dams, algal slop on bottom, water 18 C. OBSERVER: Frederick W. Schueler, Bev Wigney. 2001/194/a, Dreissena polymorpha (Zebra Mussel) (Mollusca). many juvenile, adult, under cover, seen. WAYPT/013, crust of juvs & scattered 25 mm ads und rocks. None visible from above, but a crust of juveniles and scattered adults under some turned rocks - others just throw up a cloud of black muck, and don't support any Dreissena.

Above the lower dam, a pale green alga is rolled up in floating corrugated folds beside the drift corner - where there's nothing fresh except 2 Pyganodon shells. Lots of Larus around, but not closely observed. - Bev's photos of High Falls dam as seen from above, and ruins of a gate in the dam looking downstream onto flats.

moved 0.4 km NNW.

foot of High Falls, South Nation R, Casselman. UTM 18TVF 925.2 186.8 45.32362N 75.09501W. TIME: 1343. AIR TEMP: 22, sunny, windy. HABITAT: 30-50 cm deep rocky bedrock flats@foot of shallow bedrock falls. 2001/194/ba, Dreissena polymorpha (Zebra Mussel) (Mollusca). 13/many juvenile, adult, specimen. WAYPT/014, scattered or dense und rocks, largest 32.5 mm. The largest one was on 2001/194/bb Lasmigona costata - only large ones collected. Last year I noted the water as 'turbid, ' while this year I seem (9 Oct) to recall that it was clear - but I'm not sure. Bev's photos of limestone flats looking upstream towards dam ruins, and geometric slab formations on limestone flats below dam.

(same location) TIME: 1343. 2001/194/bb, Lasmigona costata (Fluted Shell) (Mollusca). 2 shell, specimen. paucicostate 96 mm fairly fresh pair with Dreissena und rock. ...and a fairly fresh fragment. Bev's photo of the Lasimagona costata with Zebra Mussels.

(same location) TIME: 1343. 2001/194/bba, Elliptio complanata (Eastern Elliptio) (Mollusca). 1 shell, captured. fairly fresh 104.5 mm valve, not saved.

(same location) TIME: 1343. 2001/194/bbb, Lampsilis radiata (Eastern Lamp-Mussel) (Mollusca). 1 shell, captured. fairly old 73.5 mm valve, not saved.

(same location) TIME: 1343. 2001/194/bc, Orconectes virilis (Northern Crayfish) (Crayfish). 5 adult, prey of predator, under cover, specimen. 1 alive(eascaped)+4 shells left by predators, largest chela 45 mm.

(same location) TIME: 1343. HABITAT: bedrock flats@foot of shallow bedrock falls. 2001/194/bd, Rana pipiens (Leopard Frog) (herp). 4 adult, prey of predator, seen. all green, 1 ca 55 mm SVL noted on algal mat among Butomus. Bev's photo of a kettle formation in a slab of limestone.

moved 0.2 km SSE.

High Falls, South Nation R, Casselman. UTM 18TVF 926.1 185.4 45.32229N 75.09394W. TIME: 1402. AIR TEMP: 22, sunny, windy. HABITAT: limestone slabs on flats of shallow bedrock falls. 2001/194/c, Marmota monax (Woodchuck) (Mammal). 1 juvenile, seen, heard, photo. WAYPT/015, whistling from 8-10 cm space und 2 x 2 x.5 m slab. This Woodchuck gave a shore-bird like whistled call, and we walked toward it, thinking it might be a Bird until the calls came from underfoot. After we had puzzled around for a bit, I looked under the slab, saw a Mammal pressed between the bedrock and the slab, and guessed it was a Muskrat because of the semi-aquatic habitat (dead Dreissena in the now-dry bottom).

Bev pushed her camera under the rock and took a photograph of what was then clearly seen to be a juvenile Marmota, which was hopefully on a voyage of dispersal rather than planning on spending the fall and winter at the site.

moved 0.3 km SSE.

High Falls, above lower dam, South Nation R, Casselman. UTM 18TVF 926.7 182.7 45.31990N 75.09314W. TIME: 1417. AIR TEMP: 22, sunny, windy. HABITAT: 40 cm bedrock river shallows between old dams, algal slop on bottom, water 18 C. 2001/194/d, Lampsilis radiata (Eastern Lamp-Mussel) (Mollusca). 1 juvenile, specimen. 38.3 mm fresh pair found on shore among dead Dreissena. Bev's photo of Hypsizygus ulmarius (Manitoba Maple Knothole Oyster), and a cluster of Mycena here.


Subject: [NatureList] South Nation 3 Oct(II): Zebras below the Lemieux landslide

Everyone,

Neither Bev nor I had ever been to the site of the great Lemieux landslide, and she was interested in the possiblity of launcing a canoe there, and I was of course obsessively interested in finding clams of Zebra Mussels. As we drove across the bridge, we saw what looked like a limestone sill beneath the bar - which we hadn't heard of - but when we slid down the clay walls, we could see that the limestone' was really stiff clay, presumeablely residuals from the slump of the 1993 landslide. These are Bev's photos of a long section of the new bridge at Lemieux, and cracking concrete support under the Lemieux. bridge. We found lots of Zebras, and no live Unionids, as recounted in the field notes. From there we went to the Co Rd 9 bridge, 1.9 km NNW Franklins Corners, and again found blankets of Zebras. - fred. skip to contents - skip to next


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Field notes of Frederick W. Schueler --- 3 October 2001.
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Canada: Ontario: Prescott & Russell Co: South Plantangenet: South Nation R/Moose Crk, blw Lemieux bridge. UTM 18TVF 950.1 267.4 45.39617N 75.06342W. TIME: 1507. AIR TEMP: 22 ca, sunny, windy. HABITAT: Tussalago/Equisetum arvense stiff clay shore of clayey river. WAYPT/017, reference (cartigraphic reference) . nat.hist., walk. WAYPT/017, walked along E bank from here to bridge. We walked down here from the road via a fairly driveable track which came to an Acer negundo -bowered end at the mud cliff above the mouth of the creek - and from then on footing was precarious all the way. Bev's photos of me working on field notes on a clay shoal at Lemieux, and the faux limestone sill - a small rock sitting in clay slip puddle at Lemieux, slumped Leda clay below the Lemieux bridge, and another view.

There were highly interesting sprawling weeds - cf Amaranthus graecizans - along the bank, but we were so concerned with staying upright and looking for Molluscs, that we didn't divert the attention they deserved. There are bars of twisted bedded clay out in the river, which we take to be the remenants of the great Lemieux landslide, and which, from the road, we at first took to be a limestone sill across the river. But they're all stiff clay, which, with the steepness of the shore, gives very much the same feeling - hard slippery clay, nutrient & water lush scattered weeds, and the danger of slipping into invisible depths - as walking along the foot of the Scarborough Bluffs.

moved 0.2 km WSW.

South Nation R/Lemieux bridge. UTM 18TVF 948.5 266.7 45.39549N 75.06545W. TIME: 1508-1550. AIR TEMP: 22 ca, sunny, windy. HABITAT: stiff clay shore of clayey river along Tussalago/Equisetum arvense. 2001/195/ea, Dreissena polymorpha (Zebra Mussel) (Mollusca). 100's/abundant juvenile, adult, specimen. WAYPT/016, blanketing all hard substrates, largest 27 mm. Since we can't see into the water, we have no idea how extensive the mussel mats may be - the sample includes a stone and mats torn off an old bridge girder. There are dead Dreissena on rocks to 20 cm above the current water level. Bev's photo of a handful of Zebra Mussels from encrusted rock at Lemieux.

(same location) TIME: 1508-1550. 2001/195/eb, Elliptio complanata (Eastern Elliptio) (Mollusca). 1 shell, specimen. 112 mm old(subfossil)pair near bridge.

(same location) TIME: 1508-1550. 2001/195/ec, Lampsilis radiata (Eastern Lamp-Mussel) (Mollusca). 6 shell, specimen. old(subfossil)valves near bridge, largest 99 mm. Also picked one Macoma and one Hiatella shell out of the clay of the bank.

(same location) TIME: 1508-1550. 2001/195/ed, Rana pipiens (Leopard Frog) (herp). 2/few juvenile, adult, seen, captured. few along the shore, 2 captured.

NUMBER/COLOUR/SEX/SVL
1)green, j, ca 48 mm, among Equisetum arvense on shore
2).5 green, ?, ca 58 mm, on shore with broken femur

(same location) TIME: 1508-1550. 2001/195/ee, Rana clamitans (Green Frog) (herp). 2 juvenile, adult, seen, captured. 1)ca 60 mm SVL, bron, on land, 2)smaller, in river. A couple more unidentified Rana may have been this species.

(same location) TIME: 1508-1550. 2001/195/ef, Ondatra zibethicus (Muskrat) (Mammal). present adult, scat, tracks. many tracks in mud along shore - no shell piles. One wonders if Dreissena will decline (or be confined to under-rock spaces) if (when?) Muskrats begin to forage on them here.

Lemieux South Nation R bridge. UTM 18TVF 949 265. TIME: 1600. AIR TEMP: 22 ca, sunny, windy. HABITAT: grassy roadside bank. 2001/195/f, Phragmites australis (Reed) (p). 1 stand herb, in fruit, seen. noted, S of intersection. Also a DOR Mephitis mephitis on the road here.

South Nation R/Co Rd 9, 1.9 km NNW Franklins Corners. UTM 18TWF 45.4 333 45.45516N 74.94153W. TIME: 1608-1617. AIR TEMP: 21 ca, sunny, windy. HABITAT: clay-bank muddy river@bridge/boatlaunch ramp. 2001/195/aa, Dreissena polymorpha (Zebra Mussel) (Mollusca). 17/abundant juvenile, adult, specimen. WAYPT/020, all over concrete, sample is small stone, largest 21 mm. At the south bank, there is a complete dense blanket of small mussels on vertical bridge concrete, and also on below the water level on all stones associated with the boat launch - as well as other stones along the bank. Bev's photos of The steel bridge over the South Nation on Cty. Rd. 9 and a concrete support under the bridge

(same location) TIME: 1608-1617. 2001/195/ab, Elliptio complanata (Eastern Elliptio) (Mollusca). 1 shell, fd. old fairly heavy 99 mm valve on bank, not saved.

(same location) TIME: 1608-1617. 2001/195/ac, Lampsilis radiata (Eastern Lamp-Mussel) (Mollusca). 2 shell, fd. fragments of old fairly heavy valves on bank, not saved.

(same location) TIME: 1608-1617. 2001/195/ad, Zonitidae (Mollusca). 1 shell, fd. on Elliptio valve on bank.


Subject: [NatureList] South Nation 3 Oct(III): Zebras and new-to-the SNR Unionids at Jessups Falls.

Everyone,

I hadn't been to Jessups Falls, just above the mouth of the South Nation, since before the Zebra Mussels arrived, so I was prepared to be depressed by the situation there. Accordingly, the afternoon's theme, "No live clams, but lots of Zebras" was replayed for us here, but while sorting through the broken Unionid fragments Bev & I dredged out of the Zebra-swathed river I found one valve of Potamilus alatus or Pink Heelsplitter. This species was known from the Ottawa River on the basis of a very few old specimens, and remained the only species unrediscovered in the Ottawa drainage until Andre Martel found a single shell on the Duck Islands this summer. I'd set this shell aside as an undecipherable fragment, but the distinctive teeth, the hint of coloured nacre under the weathered surface, and the large size suggested Potamilis, and on checking against the books, that's what it was. There was also a small Ligumisa recta shell, which seems to be the first specimen from the South Nation.

It's sad to rediscover Potamilus at a site so thoroughly taken over by Dreissena, but one can hope that 1) Unionids persist in the main channel, where they can't be found by visual methods (i.e. shore searches or scuba - we'll have to use dredges or brails), and 2) that Potamilus may persist in the Ottawa River where the water doesn't have so much calcium as it does in the SNR. One of next summer's projects for me is going to be to map the area of the Ottawa downstream of the SNR where Dreissena can be found - presumeablely there's a plume of calcium-rich SNR water which will support them, even if the Ottawa as a whole is too soft for them. Isabelle found a few at Plaisance in the course of her survey of the Quebec side, and on my way to Montreal next week I'll check the shell piles at Hawksbury.

Bev has posted photos at her magic canoe site Just go to this link and click on "Photo Album" and you'll see an album entitled "Jessups Falls". There will be thumbnails in it and you should be able to click on the first one and then page through the album. - fred. skip to contents - skip to next


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Field notes of Frederick W. Schueler --- 3 October 2001.
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Canada: Ontario: Prescott & Russell Co: North Plantagenet: South Nation R/Hwy 17@Jessups Falls. 31G/11, UTM 18TVF 951 448.5 45.55917N 75.06238W. TIME: 1640-1737. AIR TEMP: 20, sunny, sunset, breezy. HABITAT: lawnpark, muddy river, fisher-trampled/bedrock shore near bridge. 2001/195/ba, Leptodea fragilis (Fragile Paper-Shell) (Mollusca). 21 shell, specimen. old shells, 20 valves & fragments, 1 pair, largest 94 mm. Most of these were from a pile on the E shore about 20 m above the bridge - all are old and most are broken. No living Unionidae were seen,

It's sad that this site is so thoroughly taken over by Dreissena, and that I found no living Unionidae, and only Anodontine fresh shells. But it was hard to see the bottom under the clay-turbid water because of a dark algal slurry and abundant plants. One can hope that Unionids persist in the main channel, where they can't be found by visual methods (i.e. shore searches or scuba - and we'll have to use dredges or brails).

(same location) TIME: 1640-1737. 2001/195/bb, Elliptio complanata (Eastern Elliptio) (Mollusca). 2 shell, specimen. crassidens-like pair, complanata-like valve, lgr 113.5 mm. Fairly fresh shells, decorated with Dreissena.

(same location) TIME: 1640-1737. 2001/195/bc, Ligumia recta (Black Sand-Shell) (Mollusca). 1 shell, specimen. fairly old heavy, narrow, broken 71 mm pair. This seems to be the first record of this species for the south Nation drainage - though actually this is so close to the Ottawa River as to not represent a population in the South Nation.

(same location) TIME: 1640-1737. 2001/195/bd, Utterbakia imbecillis (Mollusca). 1 shell, specimen. fresh broken valve.

(same location) TIME: 1640-1737. 2001/195/be, Pyganodon grandis (Common Floater) (Mollusca). 3 shell, specimen. old valves, intact 1 100 mm, lgr 1 broken, fresh fragment.

(same location) TIME: 1640-1737. 2001/195/bf, Potamilus alatus (Pink Heelsplitter) (Mollusca). 1 shell, specimen. old broken valve, greatest dimension 96 mm, purple-pink nacre.

(same location) TIME: 1640-1737. 2001/195/bg, Dreissena polymorpha (Zebra Mussel) (Mollusca). 100 s/abundant adult, juvenile, specimen. largest 26 mm, clustered on most stones, alive to 10 cm from surface. Flat areas of bedrock are free of this species, but piled stones and other hard substrate are densely clustered. Samples represent different size classes. The fact that the water level is above the drought-killed mussels here, while they're still exposed upstream, suggests that the water level is controlled by Ottawa River hydro dams.

The South Nation must now be injecting a plume of Dreissena larvae into the soft-water Ottawa River. One of next summer's projects for me will have to be to map the area of the Ottawa downstream of the SNR

where Dreissena can be found.

(same location) TIME: 1640-1737. 2001/195/bh, Bithynia tentaculata (European Faucet snail) (Mollusca). abundant adult, juvenile, under cover, specimen. clustered und most stones. Specimens will need to be extracted from the sample...

(same location) TIME: 1640-1737. 2001/195/bi, Rana pipiens (Leopard Frog) (herp). 1 juvenile, seen. ca 55 mm green, on waters edge.


Subject: [NatureList] South Nation 3 Oct(IV): Scotch River - Riceville and the mouth

Everyone,

As dusk began to fall, Bev and I checked a few sites along the lower Scotch River. The mouth of the river was an architypical scene of South Nation violence: steep sticky clay banks, and huge quantities of flood-washed vegetation drifted in piles many metres above the level of the rivers. The South Nation was crusted with Zebra Mussels wherever there was a bit of hard substrate, but these extended only a few metres up the Scotch River. At Riceville it was so dark I could see Unionid shells only when they were stuck in the ruins of the log-crib dam below the bridge, but one was a very striking big heavy-shelled Lampsilis, and a random handful of substrate included old Horn Snail shells - suggesting that there's a lot more than mud in this stream. Under the bridge on the way back up from the river it was so dark that I tripped over a wire basket, momentarily congratulated myself on recovering my balance, and then immediately slammed my face into the concrete beam of the bridge (fortunately without either breaking my glasses or drawing any blood). - fred. skip to contents - skip to next


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Field notes of Frederick W. Schueler --- 3 October 2001.
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Canada: Ontario: Prescott & Russell Co: South Plantangenet: Scotch R/.3 km NNW Riceville. 31G/7, UTM 18TWF 32.4 313.2 45.43740N 74.95823W. TIME: 1759. AIR TEMP: 19 ca, clear, calm, sunset. HABITAT: small muddy river in steep wooded ravine/gully valley. WAYPT/021, visit. nat.hist., seen. WAYPT/021, looking ard for canoe launch site - not here.

moved 2.9 km NW.

South Nation R/Scotch R. UTM 18TWF 8.8 330.8 45.45325N 74.98836W. TIME: 1807. AIR TEMP: 19, clear, calm, sunset. HABITAT: clay bank of clayey river/riverine thickets/Cornfields. 2001/195/ca, Elliptio complanata (Eastern Elliptio) (Mollusca). 23 shell, specimen. WAYPT/022, subfossil, 15 pairs, 8 valves, largest 118 mm. I dug these out of the bank at and below water level, from the S shore of the South Nation just above the confluence of the Scotch River. No sign of any fresh Unionidae.

(same location) TIME: 1807. 2001/195/cb, Lampsilis radiata (Eastern Lamp-Mussel) (Mollusca). 11 shell, specimen. subfossil, 2 pairs, 9 valves, largest 105 mm.

(same location) TIME: 1807. 2001/195/cc, Dreissena polymorpha (Zebra Mussel) (Mollusca). 100 s/abundant juvenile, adult, specimen. covering all hard substrates, sample a branch, largest 19 mm. Going up the steep bank of the Scotch River, the coverage of Dreissena goes from 'heavy' to 'sparse' in the few metres above the old bridge footings (the old bridge was just above the new bridge). Above this is an outlet for a new tile drain, but while no extensive hard substrate is accessible below this a branch in the water has no Dreissena on it - so one presumes this is the upstream limit of South Nation eddys that bear Zebra larvae into the mouth of the Scotch River.

There is an incredible amount of drift along the banks here - I climbed up between the bridge footings on a 6 m cliff of old Corn stalks and other drift, where only scattered Polygonum and Urtica had managed to take root - and above that there were heaps and windrows on fences and trees. Yet last spring there was no particular spate.

(same location) TIME: 1807. 2001/195/cd, Campeloma decisum (Brown Mystery Snail) (Mollusca). 1 juvenile, adult, specimen. 27.3 mm ols shell with intact spire.

(same location) TIME: 1807. 2001/195/ce, Castor canadensis (Beaver) (Mammal). present adult, tracks. many burrows & tracks along SNR, lots of Salix cut. There's a good canoe-launch site here where a small streamlet flows across a gravel pad, which one supposes is artificial - though its purpose isn't apparent.

(same location) TIME: 1807. 2001/195/cf, Rana pipiens (Leopard Frog) (herp). 1 juvenile, seen. green, on SNR bank.

moved 3.2 km SE.

Scotch R/Riceville bridge. UTM 18TWF 33.8 310.8 45.43525N 74.95639W. TIME: 1844-1900. AIR TEMP: 19, clear, calm, sunset. HABITAT: steep wooded banks of clay river in village@old wooden dams. 2001/196/aa, Pseudacris crucifer (Spring Peeper) (herp). few call, heard. few calling steadily.

(same location) TIME: 1844-1900. 2001/196/ab, Matteuccia struthiopteris (Ostrich Fern) (p). dominant herb, dead, seen. W side of valley covered with died-back leaves. The stream above the dams is heavily covered with floating leaves, including in a random handful, Basswood, Manitoba Maple, Ash, Elm, Viburnum sp. and Red Maple.

(same location) TIME: 1844-1900. HABITAT: clay/sand river in village@old wooden dams, steep wooded banks. 2001/196/ac, Lampsilis radiata (Eastern Lamp-Mussel) (Mollusca). 4 call, specimen. fairly fresh 117 mm heavy pair, 3 ca 70 mm valves. Waded around 2 broken-down wooden dames just upstream of the modern bridge - finding, in the failing light, only the shells lodged in the timbers and rocks of the dams.

(same location) TIME: 1844-1900. 2001/196/ad, Pyganodon grandis (Common Floater) (Mollusca). 1 call, specimen. fairly fresh 101 mm pair.

(same location) TIME: 1844-1900. 2001/196/ae, Campeloma decisum (Brown Mystery Snail) (Mollusca). 5 call, specimen. old shells, largest 27 mm, spires intact.

(same location) TIME: 1844-1900. 2001/196/af, cf Goniobasis livescens (Great Lakes Horn Snail) (Mollusca). 6 shell, specimen. old(subfossil?)shells, largest 14 mm, spires. May be some other Pleuocentrid? The incidental sandy bottom sample that came along with the Campeloma and Unionidae also includes LIST:

Physa, 1 gyrina-like shell;

Fossaria cf exiqua, 1 shell;

Sphaerium, few shells.

Canada: Ontario: Ottawa-Carleton Region: Osgoode: Reg Rd 6, Bev Wigney's/2.4 km SW Enniskerry. 31G/4, UTM 18TVF 537.9 32 45.18273N 75.58782W. TIME: 2029. HABITAT: brushy organic homestead surrounded by turf farms. WAYPT/023, reference (cartigraphic reference) . drive. WAYPT/023, arrived here and then drank coffee with Don until Aleta was appalled at how late I got home..


Subject: [NatureList] Zebra Mussels in Mississippi Lake

Everyone,

Pitsulak Vachon brought some Zebra Mussels into the EOBM this summer, and this is an account of my visit there to check them out. There aren't many, and I hope it remains that way - I'm not sure how much of the water in the Upper Mississippi comes off the Shield and is calcium-deficient, but it's possible that the Zebra populations will be limited by lack of calcium - and then there's the question of the damage that may be done to the diverse Unionid fauna downstream of Almonte (the endangered River Redhorse population there shouldn't be threatened, since Moxostoma are mollusivorous). I haven't had any reply to my attempt to interest the Mississippi Valley CA in our discovery of Zebras in their watershed. skip to contents - skip to next


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Field notes of Frederick W. Schueler --- 4 October 2001
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(at home) TIME: 1413. AIR TEMP: 20, sunny, windy. ROUTE: Bolton Rd, DHR, Roger Stevens, Hwy 43, Hwy 7, Miss.W Shore, Hwy 7, DHR.... OBSERVER: Frederick W. Schueler. hondalog, departure . nat.hist., drive. 239155 km, to Mississippi Lake to check out Zebra Mussels. I saw 2 AOR Thamnophis sirtalis on the southern part of Bolton Road, but didn't stop for them, as I was closely pursued by a school bus.

moved 43.7 km WNW.

Canada: Ontario: Lanark Co: Drummond: Mississippi L, Mac Culloughs Landing. 31F/1, UTM 18TVE 40.6 854.8 45.01828N 76.21728W. TIME: 1543-1728. AIR TEMP: 20 ca, sunny, windy. HABITAT: treed-lakeshore lawn campsite, clear water, sand/flat bedrock bottom, water 17 C. OBSERVER: Frederick W. Schueler, Pitsulak Vachon. 2001/196/baa, Dreissena polymorpha (Zebra Mussel) (Mollusca). common juvenile, specimen. WAYPT/024, from flat plastic bottom offshore floating dock. These little mussels at a density of about 150/sq m on big flat plastic undersides of the campsites multisegmented 24 m dock - but denser (now scraped off) along the edges - few under the float that abutted the shore, and more in the deeper segments (sample from penultimate segment). This is the first year they have seen them here.

There aren't a lot Dreissena here. This summer Pitsulak checked Greig I, in the middle of the lake and fd no Dreissena, and even down near her house, where she found the ones she brought to Fitz Roy this summer, she couldn't find them predictablely. The water was lower during the summer (30 cm?) and is lowered by MVCA in the winter, about the same amount. Now full to normal levels.

At Pitsulak's place whence the August sample 18 TVE 042 852 it was rare to find many under a stone - many of the boat launchers don't care if they're carrying Dreissena.

(same location) TIME: 1543-1728. 2001/196/bab, Dreissena polymorpha (Zebra Mussel) (Mollusca). few juvenile, specimen. on Unionid shells.

(same location) TIME: 1543-1728. 2001/196/bb, Elliptio complanata (Eastern Elliptio) (Mollusca). few adult, shell, specimen. commonest sp, many broken, many leaving tracks in shallows. This was the predominant Unionid, though never hugely abundant. Live ones had come up to the 8 cm shallows with the rising water, and are leaving tracks in the sand.

I waded 300 m of shore, out to 50 cm depth much of the shore - vegetation is submerged sedge and Potomogeton, but every where sparse. There were scattered Unionids and shells, and many of the shells broken, probably mostly by campers...

(same location) TIME: 1543-1728. 2001/196/bc, Pyganodon cf grandis (Common Floater) (Mollusca). few adult, shell, specimen. small, scattered fresh shells, 2 alive, 1 taken.

(same location) TIME: 1543-1728. 2001/196/bd, Lampsilis radiata (Eastern Lamp-Mussel) (Mollusca). few juvenile, shell, specimen. fewest shells, small 1 alive.

(same location) TIME: 1543-1728. 2001/196/be, Orconectes virilis (Northern Crayfish) (Crayfish). 1 adult, dead, specimen. dead on shore only Crayfish seen.

(same location) TIME: 1543-1728. 2001/196/bf, Lemna trisulca (Star Duckweed) (p). abundant herb, dead, seen, drift. most of the sparse vegetative drift on shore.

(same location) TIME: 1543-1728. 2001/196/bg, Viviparus georgianus (Banded Mystery Snail) (Mollusca). many shell, specimen, specimen. sunken drifts of shells-handsfulls taken with other spp..

moved 0.3 km N.

Mississippi L, Mac Culloughs Landing. UTM 18TVE 40.2 857.8 45.02093N 76.21789W. TIME: 1712. AIR TEMP: 20 ca, sunny, windy. HABITAT: treed-lakeshore lawn campsite, clear water, sand/flat bedrock bottom, water 17 C. OBSERVER: Frederick W. Schueler. WAYPT/025, visit. -. WAYPT/025, as far along the lake as I searched.

moved 4.4 km NW.

Hwy 7/Mississippi R, Innisville. UTM 18TVE 15 894 45.05320N 76.25052W. TIME: 1746-1810. AIR TEMP: 19 ca, sunny, windy. HABITAT: shallow bedrock rapids of clear river with cottages. 2001/196/ca, Pandion haliaetus (Osprey) (Bird). 1 adult, seen, heard. flying over river shallows.

(same location) TIME: 1746-1810. 2001/196/cb, Lampsilis radiata (Eastern Lamp-Mussel) (Mollusca). several adult, shell, seen. scattered on the bottom, sev out from und cover, few shells. ...waded down to #26 rocky island just at head of pooled Mississippi Lake. NO:Orconectes and NO:Dreissena polymorpha seen in turning numerous rocks - but sun low, and water recently higher than it has been though lower than at crest. Lots of rocky damlets put up by cottagers in midstream, and other re-arrangements of the rocks. Typical (small, compact) Upper Mississippi representatives of the genus.

(same location) TIME: 1746-1810. 2001/196/cc, Pyganodon cf grandis (Common Floater) (Mollusca). several adult, shell, seen. scattered on the bottom, sev out from und cover, few shells. Typical (small, compact) Upper Mississippi representatives of the genus.

(same location) TIME: 1746-1810. 2001/196/cd, Elliptio complanata (Eastern Elliptio) (Mollusca). several adult, shell, seen. a few shells & a few und rocks. Typical (small, compact) Upper Mississippi representatives of the genus.

(same location) TIME: 1746-1810. 2001/196/ce et seq, Sphaerium (Mollusca). several adult, shell, specimen. from a handful of bottom gravel.

moved 0.2 km ESE.

head of Mississippi L, blw Innisville bridge. UTM 18TVE 16.5 893.4 45.05271N 76.24867W. TIME: 1755. AIR TEMP: 19 ca, sunny, windy. HABITAT: rocky islet in shallow bedrock rapids of clear river with cottages. WAYPT/026, visit. nat.hist., wade. WAYPT/026, waded here from bridge, at head of still lakewater.


Subject: Re:[NatureList] Unionids of the Jock River @ the Dwyer Hill Rd

Everyone,

On the way back from Mississippi Lake, I stopped at the Jock River to see how things had changed since Eric Snyder and I found drought-exposed Unionid shells here on 28 July... skip to contents


==========================================================
Field notes of Frederick W. Schueler --- 4 October 2001
==========================================================

Canada: Ontario: Ottawa-Carleton Region: Goulbourn: Jock R/Dwyer Hill Rd. 31G/4, UTM 18TVF20 233 0.5 45.15180N 75.97535W. TIME: 1845-1903. AIR TEMP: 17 ca, clear, sunset, windy. HABITAT: dry riffle of rocky muddy slow creek in ungrazed pasture, no flow. 2001/196/d, Unionidae (Unionid Mussel) (Mollusca). 170 shells, prey of predator, specimens. stopped to see if stream was flowing & fd many new shells. ...still no flow though water higher than it was at lowest - several big (40 cm) fish along the shore of the under-bridge pool, and many Rana tadpoles among pebbles and sparse weeds at its shallow upstream edge. Gathered almost all of the freshly opened shells between the pools on the surface of the gravelly riffle - about 10 m of riffle. An astonishing number of un-munched clams, most with fairly wide periostracum fringes beyond the calcified shell - a few shells with single puncture holes, appropriate for a Raccoon canine, in each valve as if found by Procyon by smell after the Unionids died in the substrate. Gathered a full 7 litre popcorn bag - a late drought mortality sample. (These specimens now deposited in the New Brunswick Museum - 26 October 2001).

In comparison with the sample of 120 shells found here on 28 July, Elliptio (56, 62), Lampsilis radiata (5, 10), Pyganodon (11, 12), and Lasmigona costata (9, 10) haven't changed in abundance (p=0.05 2 x 2 G tests of each species vs the rest of the sample), while Anodontoides ferrusacianus (16, 0, G=23) seems to have decreased, and Lasmigona costata (2, 13, G=5.9), and Strophitus undulatus (21, 63, G=13) seem to have increased - but it's not clear what this means. Does decreased abundance mean that only those individuals that were on the surface when the water receeded were vulnerable to predation, and others are successfully estivating through the drought, or that they were wiped out early so that there were none available to predators during August and September? And have the species that increased been more resistant to drought, only dying or falling to predation at the last extremity, or were they, once surface-living individuals were picked off, the more vulnerable. I suppose the question could only be answered now by digging up the whole riffle to see which species, if any survive, or by a cm-by-cm survey of the riffle once the water returns to find and identify living individuals.

It's too bad we didn't get a sample here during the 1999 drought, because I'm sure that the age structure and species composition of the sub-populations in this riffle will be strongly influenced for years by this mortality, and it's possible that the large number of young indiduals suggests that bigger ones died in 1999.

(same location) TIME: 1845-1903. 2001/196/da, Elliptio complanata (Eastern Elliptio) (Mollusca). 62 shell, prey of predator, specimen. 53 fresh, 9 not-fresh, largest 115 mm. Fresh pairs: 78, 83.5, 69, 78.5, 67.5, 65, 62.5, 75.5, 82, 79, 75.5, 78.5, 83.5, 71.5, 68, 73.5, 71.5, 50, 76.5, 74, 79, 72.5, 77, 66, 76, 65.5, 76.5, 68, 79.5, 75.5, 79, 70.5, 65.5, 69.5, 66, 57, 56, 47.5, 65.5, 60.5, 67, 58, 61, 86, 84, 87, 72.5, 71, 78, 72, 55 mm.
fresh valves: 82, 67 mm.
fresh: n=53 mean=71.25 (47.50 - 87.00) st.dev.=8.95
not-fresh pairs: 71, 84, 77, 72, 79.5, 115, 72, 73, the big one is very thick-shelled and anteriorly inflated.
not-fresh valves: 70 mm
not-fresh: n=9 mean=79.28 (70.00 - 115.00) st.dev.=13.35

(same location) TIME: 1845-1903. 2001/196/db, Pyganodon grandis (Common Floater) (Mollusca). 12 shell, prey of predator, specimen. 11 fresh, 1 not-fresh, largest 100.5 mm. Fresh pairs: 63, 65, 71.5, 68.5, 65, 62, 67, 59.5 mm.
fresh valves: 63.5, 60 ca, 66 ca mm.
fresh: n=11 mean=64.64 (59.50 - 71.50) st.dev.=3.42
old valve: 100.5

(same location) TIME: 1845-1903. 2001/196/dc, Lampsilis radiata (Eastern Lamp-Mussel) (Mollusca). 10 shell, prey of predator, specimen. fresh, largest 97 mm. No clear sexual dimorphism - nacres white - larger shells unrayed.
male-like fresh pairs: 97, 70.5, 63, 79.5, 95 mm. n=5 mean=81.00 (63.00 - 97.00) st.dev.=13.33
female-like fresh pairs: 86.5, 82.5, 88, 89, 85.5 mm. n=5 mean=86.30 (82.50 - 89.00) st.dev.=2.25
pooled - n=10 mean=83.65 (63.00 - 97.00) st.dev.=9.92

(same location) TIME: 1845-1903. 2001/196/dd, Lasmigona costata (Fluted Shell) (Mollusca). 13 shell, prey of predator, specimen. fresh, largest 98.5 mm. Fresh pairs: 98.5, 86.5, 84.5, 82, 74, 69.5, 57, 58.5, 59, 49, 65, 58, 70 ca mm. n=13 mean=70.12 (49.00 - 98.50) st.dev.=13.83

(same location) TIME: 1845-1903. 2001/196/de, Lasmigona compressa (Brook Lasmigona) (Mollusca). 10 shell, prey of predator, specimen. fresh, 8 pairs, 2 valves, largest 76.5 mm. Fresh pairs: 76.5, 63, 63, 59.5, 62.5, 55, 45, 45 mm.
fresh valves: 59, 64 mm.
fresh: n=10 mean=59.25 (45.00 - 76.50) st.dev.=8.85

(same location) TIME: 1845-1903. 2001/196/df, Strophitus undulatus (Squaw-Foot) (Mollusca). 63 shell, prey of predator, specimen. 52 fresh pairs, 11 fresh valves, 1 not-fresh pair, largest 80.5 m. Fresh pairs: 68, 61, 63.5, 53, 67, 77, 66.5, 75, 66.5, 80.5, 68, 64.5, 62, 62, 58, 56.5, 53, 70, 70.5, 56.5, 52, 76.5, 63, 70, 58.5, 60, 56, 61, 64, 67, 70.5, 64, 54, 46, 52, 68.5, 64, 57, 56.5, 52, 45, 60.5, 50.5, 52.5, 52, 60, 49, 61.5, 56, 73.5, 70.5 mm.
fresh valves: 70, 70.5, 65, 61, 65.5, 61.5, 61.5, 62, 60.5, 59.5, 61.5 mm.
fresh: n=62 mean=61.95 (45.00 - 80.50) st.dev.=7.63
not-fresh pair: 73 mm.
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