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Research about Cayuga Lake

Source-linked reports with geographic coverage including Cayuga Lake.

3 recordsLinked to original sources

Nuclear eDNA estimates population allele frequencies and abundance in experimental mesocosms

Advances in environmental DNA (eDNA) methodologies have led to improvements in the ability to detect species and communities in aquatic environments, yet the majority of studies emphasize biological diversity at the species level by targeting variable sites within the mitochondrial genome. Here, we demonstrate that eDNA approaches also have the capacity to detect intraspecific diversity in the nuclear genome, allowing for assessments of population-level genetic diversity and estimates of the number of genetic contributors in a sample. Using a panel of microsatellite loci, we evaluated intraspecific genetic diversity in the round goby (Neogobius melanostomus) using eDNA samples from experimental mesocosms. First, we tested the similarity between eDNA and individual tissue-based estimates of allele frequencies. Subsequently, we used a likelihood-based DNA mixture framework to estimate the number of unique genetic contributors in mesocosm eDNA samples and in simulated mixtures of alleles. Allele frequencies from eDNA accurately reflected allele frequencies from genotyped round goby tissue samples, indicating nuclear markers can be reliably amplified from water samples under controlled conditions. DNA mixture analyses were able to estimate the number of genetic contributors from eDNA samples and simulated mixtures of DNA from up to 58 individuals, with the degree of positive or negative bias dependent on the filtering scheme of low-frequency alleles. This study is the first to document the application of eDNA and multiple amplicon-based methods to obtain intraspecific nuclear genetic information and estimate the absolute abundance of a species in mesocosms. With proper validation, this approach has the potential to advance non-invasive survey methods to characterize populations and broadens the application of eDNA methodologies to inform population-level management objectives.

New York

Seasonal habitat use indicates that depth may mediate the potential for invasive round goby impacts in inland lakes

The round goby ( Neogobius melanostomus ) is among the fastest-spreading introduced aquatic species in North America and is radiating inland from the Great Lakes into freshwater ecosystems across the landscape. Predicting and managing the impacts of round gobies requires information on the factors influencing their distribution in habitats along the invasion front, yet this information is not available for many recently invaded ecosystems. We evaluated the seasonal habitat use and biomass of round gobies in an inland temperate lake to define the spatiotemporal scope of biological interactions at the leading edge of the round goby invasion. Using novel statistical approaches, we combined hierarchical models that control for imperfect species detection with flexible smooth terms to describe non-linear relationships between round goby abundance and environmental gradients. Subsequently, we generated accurate detection-corrected estimates of the standing stock biomass of round gobies. Our results show seasonally differentiated habitat niches, where suitable round goby habitat in summer months is restricted to shallow depths (<18.4 m) with a mixture of vegetative and mussel cover. We found high round goby biomass of 122 kg/ha in occupied habitats during the summer, with a total lake-wide biomass of 766,000 kg. In winter, round gobies migrate to deep offshore habitats and disperse, dramatically altering their scope for biological interactions with resident aquatic species across summer and winter seasons. The results of this study indicate that the scope of biological interactions in inland lakes may be seasonally variable, with potential for high round goby biomass in shallow lakes or at the periphery of deep lakes in the summer months. Such shallow-water habitats may therefore present higher risk of ecological impacts from round gobies in invaded lentic ecosystems. As round gobies expand inland, consideration of seasonal habitat use will be an important factor in predicting the impacts of this pervasive invader.

New York

Radium isotopes in Cayuga Lake, New York: Indicators of inflow and mixing processes

Naturally occurring radium isotopes ( 223 Ra, 224 Ra, 226 Ra, and 228 Ra) were measured in lake and tributary water of Cayuga Lake, New York, during the course of a vernal inflow event in the spring of 2001. A large influx of groundwater, probably from a carbonate aquifer, entered the lake at its extreme southern end early in the vernal inflow event and spread northward, covering an extensive part of the southern end of the lake. The low 228 Ra/ 226 Ra activity ratio of this water mass, compared with bulk lake water, allowed its identification through time. Estimates of mixing with bulk lake water were calculated from changes in the 226Ra content. Groundwater inflow to the lake around the delta of a major tributary was detected on the basis of 223 Ra and 224 Ra activity of lake and tributary water. Inflow of a water mass to the surface of the lake was also detected using 223 Ra and 224 Ra activity. The integrity of this water mass was monitored using short‐lived radium isotopes. Suspended sediment in the lake water is a source of the short‐lived radium isotopes 223 Ra (~2 x 10 −4 dpm L −1 ) and 224 Ra (~3 x x 10 −3 dpm L −1 ), but bottom sediments are a more significant source of 228 Ra. Radium isotopes can be valuable new tools in limnological investigations, allowing detection and monitoring of events and processes such as water inflow and mixing, determining sources of inflowing water, and monitoring introduced water masses as they move within the lake.

New York