Unadilla River Pearly mussels survey1 Solomon Maricle2

ABSTRACT

As part of an ongoing survey of pearly mussel populations in the watershed, 13 sites on the Unadilla River were examined. The purpose of this survey was to assess the status of mussel species currently populating the river and determine if any species of greatest conservation need (SGCN) were present. Sites were chosen based on ease of access. We searched visually, by use of snorkel and mask, or glass bottomed buckets. We conclude that pearly mussel species previously found are stable and that there might be population expansion Pyganodon cataracta, and Lasmigona subviridis. As expected, Alasmidonta varicosa was not present.

INTRODUCTION The current status of pearly mussel species in the Unadilla River, (UR) is in question. As part of an on-going survey (Lord, et al., 2010), the focus of this survey is to assess the status of mussel species currently populating the UR and determine if and what specieds of greatest concern need (SGCN) are present. Of particular concern, because of the UR’s placement within the Susquehanna watershed, are the following four pearly mussel species: Alasmidonta varicosa (Brook floater), Alasmidonta marginata (Elktoe), Lasmigona subviridis (Green floater) and Lampsilis cariosa (Yellow lampmussel). These species are deemed SGCN by the New York Department of Environmental Conservation, because of their endangered, threatened or special concern status; funding for the needs of these species, and their conservation, depends on their current status. Researchers of past surveys (Strayer and Fetterman 1999) conclude that, despite obvious affliction of both water quality and habitats from 1965 to 1997, there was little change in mussel communities and richness. In 2006, heavy flooding of the Susquehanna watersheds occurred, removing and relocating enormous quantities of soil and debris (Susquehanna River Basin Commission 2007). This may have had a detrimental effect on UR unionid species. This was the only known flood within the watershed since 1997.

FIELD SITE DESCRIPTION The Unadilla River, 71 miles in length, runs from south of Utica to the Village of Sidney, where it empties into the Susquehanna River, the largest freshwater provider for the . The river winds through a mixture of wooded, agricultural and suburban settings with a majority of its length winding through agricultural fields, used both actively and lying fallow.

1 For a complete version of this redacted report, contact Mr. Thomas Bell,Project Manager and State WildlifeGrant’s Biologist, 1285 Fisher Ave. Cortland, NY 13045. 2 BFS volunteer intern, summer 2010. METHODS We chose search locations based on their ease of access: locations close to a road or path that allowed easy access to the river. Google Earth TM and Google Maps TM were used to find these search locations. Altogether, twenty-eight sites were chosen. Primarily, searches were conducted by means of mask and snorkel at each site although, if water was one foot or less in depth, searches were conducted by scanning the river bottom with a glass bottomed bucket while wading. On average, 80-100 m lengths of river were searched upstream of an access point in a 2 to 3 hour period. The riverbed was scanned thoroughly, swimming from one shoreline to the other, unless conditions did not permit it (e.g., too strong of a current, depth of water greater than 2m). Moving 1-1.5m upstream and then swimming back to the original shoreline 1-1.5m upstream of the previous crossing point was the search pattern used. The chances of overlooking mussels were reduced using this pattern repeatedly, and it allowed for a thorough examination. Using a handheld GPS device, I took UTM coordinates at the start and end of each area surveyed (Table. 1).

I did not identify spent valves on location, but bagged, labeled, and later positively identified each. I removed each live mussel from the river bottom for examination and identified all of them on site. The number of each species was recorded in a notebook and later transferred to a Microsoft® Excel® spreadsheet. Live mussels removed from the river bottom were replaced in the same spots from which they were removed and, if needed, this was done by excavating a small hole in the river bed and pushing the point on the mussel where the anterior and ventral sides converge, down into the riverbed and pointing the posterior end upstream. I identified mussels found, using a copy of Strayer and Jirka’s (1997), if there was any uncertainty as to the species. If any doubt remained as to the identity of the specimen, digital photos were taken from multiple angles and sent via e-mail, for consultation. Finally, spent valves were shown to Lord to validate my identifications.

RESULTS Out of thirteen sites examined (Fig. 1), eight living species of mussels were found in the UR (Fig. 2 and Table. 1 and 2). Site 12 contained no spent valves. In the sites containing no live mussels, the substrate consisted mostly of large rounded cobblestone as well as artificial stone, typically cement. River clarity at these points was extremely low; mainly because of sediment remaining suspended due the slow movement of the water created by the meandering course of the river.

At most of the sites surveyed, mussel numbers were meager, especially in areas where water was flowing at a rapid rate, creating turbid water conditions. In the sites containing the great number and richness of species, water clarity was excellent, a noticeable current was present, and the water depth did not exceed 1 m. Locations near the headwater of the UR contained the largest number of mussels in any area surveyed (Table. 2). Alasmidonta undulata (Triangle floater) and Strophitus undulatus (Creeper) were the most numerous of all species found. Distribution was fairly even for all species but numbers for most were sparse. Yellow lampmussel and Lampsilis radiata (Eastern lampmussel) were the least numerous and the least distributed. All Elktoe at Site 5, were found directly under the bridge where water depth was the deepest at 1 – 1.5 m and where the current was strongest. No traces of live or dead Brook floater were found in the UR. Additionally, Dreissena polymorpha (Zebra mussels) were not found at any of the sites searched.

Table 1. Date, UTM coordinates, description of location of each site, time spent in the water and depth of the water for all sites in the Unadilla River for pearly mussels for 2010.

Site/Waypts Date Site/Waypts UTM'S Site Water Depth

1/001 - 002 03-Jul-10 1/001 - 002 Redacted Redacted 30cm – 1.2m 2/003 - 004 03-Jul-10 2/003 - 004 Redacted Redacted 12.7cm – 61cm 3/005 -006 11-Jul-10 3/005 -006 Redacted Redacted 15.2cm – 1.2m 4/007 -008 11-Jul-10 4/007 -008 Redacted Redacted 30.5cm – 1.5m 5/009 -010 12-Jul-10 5/009 -010 Redacted Redacted 12.7cm- 91.4cm 6/011 - 012 14-Jul-10 6/011 - 012 Redacted Redacted 12.7cm-61cm 7/013 - 014 16-Jul-10 7/013 - 014 Redacted Redacted 12.7cm – 61cm 8/015 - 016 16-Jul-10 8/015 - 016 Redacted Redacted Highly Variable 9/017 - 018 20-Jul-10 9/017 - 018 Redacted Redacted 61cm– 1.8m 10/019 -020 27-Jul-10 10/019 -020 Redacted Redacted 30.5cm– 91.4cm 11/021 -022 2-Aug-10 11/021 - 022 Redacted Redacted 15.3cm – 45.7cm 12/023 -024 7-Aug-10 12/023 - 024 Redacted Redacted 15.2cm – 1.8m 13/025 -026 7-Aug-10 13/025 - 026 Redacted Redacted 15.2cm – 91.4cm

Table 2. Numbers of live and dead mussels found at each Unadilla River site surveyed for pearly mussels in 2010. L. cariosa = Lampsilis cariosa; A. marginata = Alasmidonta marginata; A. varicosa = Alasmidonta varicosa; L. subviridis = Lasmigona subvirdis; E. complanata = Elliptio complanata; L. radiata = Lampsilis radiata; A. undulata= Alasmidonta undulata; S. undulatas = Strophitus undulatus; P. cataracta = Pyganadon cararacta; and M. margaritifera= Margaritifera margaritifera

L. cariosa A. marginata A. varicosa L. subviridis E. complanata L. radiata A. undulata S. undulatus P. cataracta M. margaritifera

Sites Live Dead Live Dead Live Dead Live Dead Live Dead Live Dead Live Dead Live Dead Live Dead Live Dead 1 0.5 9 15 19 9.5 42 2 57 18.5 37 22 43.5 1 3 1 4 0.5 1.5 5 12 2 1 4 6 8 5 13 5 30+ 32 13 1 5 15 2 30+ 5 30.5 7 4 8 7 31 12 8 2 29 31.5 2 2 3.5 84.5 0.5 9 1.5 110 1 1.5 10 4 7 5 32 0.5 31.56 0.5 932 11 4 10 13 9 21.5 31311 2 6111 12 13 1 5.5 1 212 5.5 1 2 3.5 1

DISCUSSION

The pearly mussel species we found in the UR compared favorably with past survey results, and indicated that the mussel species Eastern lampmussel, Elktoe, Triangle floater, Elliptio complanata (Eastern elliptio), Pyganodon cataracta (Eastern floater), Green floater, Creeper, and Yellow lampmussel were still abundant; Eastern floater and Green floater appeared to have expanded slightly, compared to Harman’s survey (Harman 1970). Sediment deposition could have harmful effects on mussels (Strayer and Fetterman 1999). Perhaps, due to a decrease in agricultural practices, which would have decreased the amount of sediment deposition in the UR, these particular species were able to expand their populations. Artificial substratum and water conditions in parts of the river where the water moves slower, allows for an increase in suspended particles, which may be harmful for pearly mussels.

Harman’s survey of the Susquehanna watersheds (Harman 1970) showed stable populations of Margaritifera margaritifera (Eastern pearlshell), now a SGCN, and Brook floater. Strayer’s survey yielded neither Freshwater pearly mussel nor Brook Floater in the Unadilla River (Strayer and Fetterman 1999). Based on the 1999 survey, we expected that neither would be present in the UR. One spent valve of what was believed to be an Eastern pearlshell was discovered a short distance from the uppermost part of the UR. There were expectations that Zebra mussels would be present, due to their current status in New York State’s waterways, but none were found. Additionally, we noted that at Sites 8 and 9, there were heavy deposits of calcium on nearly all the spent valves of Eastern elliptio found, and these valves were noticeably thicker than Eastern elliptio found without traces of calcium. The reasons for the increase of calcium at these sites are unknown. Our search pattern was irregular and lack of data may have led to erroneous conclusions based on the pearly mussels found, particularly Eastern floaters and Green floaters. Additionally, water temperatures, in areas that appeared to be prime areas for pearly mussels but which yielded few or none, were notably elevated and felt warm to the touch. The water at sites 2, 6, 7, and 8, which yielded the highest number of pearly mussels, was extremely cold. These sites were located in more remote areas with dense tree coverage on both banks. The combination of my irregular search, with the potential that the SGCN, Eastern Pearlshell, and Brook floater may be present in the UR, and that large portions of the UR have yet to be surveyed, leads to this conclusion; that this pearly mussel survey should be followed by a more comprehensive survey of the UR, particularly before Zebra mussels expand into it.

Figure. 1. Outline of all of Unadilla River. Black dots represent sites surveyed. Otsego and Chenango County, as well as the state border included to give frame of reference. See Tables 1 and 2.

Figure. 2. Black dots represent presence of individual live mussel species in the Unadilla River sites searched for pearly mussels in 2010. Images labeled with species of mussels located there.

ACKNOWLEDGEMENTS

I am thankful to Paul Lord who was my teacher throughout this project, facilitating my work. I am also thankful to Tim Pokorny, who provided me with a profuse stream of support and knowledge throughout the duration of this project. Lastly, I offer my thanks and regards to all of those who supported me in any respect during the completion of my project.

LITERATURE CITED

Harman, W. N. (1970). New distribution records and ecological notes on central New York Unionacea. The American Midland Naturalist , 84, 46-58.

Harman, W. N., & Lord, P. H. (2010, May 10). Year 2: Susquehanna freshwater mussel surveys. Retrieved August 22, 2010, from Biological Field Station for SUNY Oneonta.

Strayer, D. L., & Fetterman, A. R. (1999). Changes in the distribution of freshwater mussels (Unionidae) in the upper Susquehanna River basin, 1955-1965 to 1996-1997. American Midland Naturalist , 142, 328-339.

Strayer, D. L., & Jirka, K. J. (1997). The Pearly Mussels of New York State. Fort Orange Press Incorporated.

Susquehanna River Basin Commission. (2007, July 27). June 2006 Flood Summary. Retrieved August 26, 2010, from Susquehanna River Basin Commission.