Assessment of Invasive Quagga Mussel Populations and Forced Circulation Devices on Lake Water Temperature in Otsego Lake, NY

Abstract

Aquatic invasive species pose a threat to our local ecosystems and can have economic impacts. Quagga mussels (Dreissena bugensis) and Zebra mussels (Dreissena polymorpha) are two types of invasive bivalves from Ukraine that have infiltrated Otsego Lake, in Otsego County, New York. Quagga mussels were recently identified in the Northern end of the lake on August 22, 2020. Both Quagga and Zebra mussels can be transported from water body to water body via watercrafts, fishing gear and other recreational equipment. Quagga mussels can survive and reproduce in deeper waters compared to zebra mussels. This poses a problem as reproductive females of Quagga mussels were observed in Lake Erie at a depth of 37 and 55 m, with temperatures ranging from 6 and 4.8°C respectively (Roe and MacIsaac 1997). Therefore, it can be expected that Quagga mussels could potentially colonize Otsego Lake all the way to the bottom. Additionally, several forced air circulation devices are found around Otsego Lake, including at the SUNY Oneonta Biological Field Station boathouse. These devices known as “ice eaters” prevent the formation of ice on the surface as it runs continuously through the winter. The artificial loss of ice at the surface, eliminates the natural “reverse stratification” where deeper water (4 to 5°C in Otsego Lake) is well protected from decreasing temperatures due to the less dense water and ice at the top. However, if more shoreline artificially loses ice, there could be faster “lake-wide-ice-out” in the spring when solar radiation and warmer air heat the surface of the water faster in the absence of snow or ice. Mussel sample traps will be deployed at several locations around Otsego Lake including locations near an “ice eater” and in deeper parts of the lake. In May, the traps will be collected and both Quagga and Zebra mussels will be tallied, sized, and estimated for age using the ridges located on the surface of the shell. Temperature loggers will be deployed by a rope attached to an anchor at strategic locations around the “ice eater” at BFS Boathouse. This will then capture data from the area affected by the artificial circulation as well control sites that have otherwise similar bathymetric and shoreline characteristics. This research aims to evaluate the ability of Quagga mussels to survive and grow during the winter of 2021, and this will be compared to the established Zebra mussel. This study also aims to determine the effects of continuous forced air circulation on lake water temperature. The results will aid in predicting the possible consequences of continued forced circulation on lake-wide thermal dynamics and how this may influence water quality. Additionally, the results from the mussel traps may reveal potential effects of ice eaters on the population dynamics between Zebra mussels and the recently introduced Quagga mussels.