Geology topics

Amanda Susanne Ackiss

Publications and source records attributed to Amanda Susanne Ackiss.

21 records · Page 2Linked to original sources

USGS2022

Results of the collaborative Lake Ontario bloater restoration stocking and assessment, 2012–2020

Bloater, Coregonus hoyi , are deepwater planktivores native to the Laurentian Great Lakes and Lake Nipigon. Interpretations of commercial fishery time series suggest they were common in Lake Ontario through the early 1900s but by the 1950s were no longer captured by commercial fishers. Annual bottom trawl surveys that began in 1978 and sampled extensively across putative bloater habitat only yielded one individual (1983), suggesting that the species had been locally extirpated. In 2012, a multiagency restoration program stocked bloater into Lake Ontario from gametes collected in Lake Michigan. From 2012 to 2020, 1,028,191 bloater were stocked into Lake Ontario. Bottom trawl surveys first detected stocked fish in 2015, and through 2020 ten bloater have been caught (total length mean = 129 mm, s.d. = 44 mm, range: 96–240 mm). Hatchery applied marks and genetic analyses confirmed the species identification and identified stocking location for some individuals. Trawl capture locations and acoustic telemetry suggested that stocked fish dispersed throughout the main lake within months or sooner, and the depth distribution of recaptured bloater was similar to historic distributions in Lake Ontario and other Great Lakes. Predicted bloater trawl catches, based on modeled population abundance and trawl survey efficiency, were similar to observed catches, suggesting that post-stocking survival is less than 20% and contemporary bottom trawl surveys can quantify bloater abundance at low densities and track restoration.

Lake Ontario↗

USGS2021

Genomic and environmental influences on resilience in a cold-water fish near the edge of its range

Small, isolated populations present a challenge for conservation. The dueling effects of selection and drift in a limited pool of genetic diversity make the responses of small populations to environmental perturbations erratic and difficult to predict. This is particularly true at the edge of a species range, where populations often persist at the limits of their environmental tolerances. Populations of cisco, Coregonus artedi , in inland lakes have experienced numerous extirpations along the southern edge of their range in recent decades, which are thought to result from environmental degradation and loss of cold, well-oxygenated habitat as lakes warm. Yet, cisco extirpations do not show a clear latitudinal pattern, suggesting that local environmental factors and potentially local adaptation may influence resilience. Here, we used genomic tools to investigate the nature of this pattern of resilience. We used restriction site-associated DNA capture (Rapture) sequencing to survey genomic diversity and differentiation in southern inland lake cisco populations and compared the frequency of deleterious mutations that potentially influence fitness across lakes. We also examined haplotype diversity in a region of the major histocompatibility complex involved in stress and immune system response. We correlated these metrics to spatial and environmental factors including latitude, lake size, and measures of oxythermal habitat and found significant relationships between genetic metrics and broad and local factors. High levels of genetic differentiation among populations were punctuated by a phylogeographic break and residual patterns of isolation-by-distance. Although the prevalence of deleterious mutations and inbreeding coefficients was significantly correlated with latitude, neutral and non-neutral genetic diversity were most strongly correlated with lake surface area. Notably, differences among lakes in the availability of estimated oxythermal habitat left no clear population genomic signature. Our results shed light on the complex dynamics influencing these isolated populations and provide valuable information for their conservation.

Wisconsin↗

USGS2021

Genomics reveals identity, phenology and population demographics of larval ciscoes (Coregonus artedi, C. hoyi, and C. kiyi) in the Apostle Islands, Lake Superior

We demonstrate, for the first time, the ability to reliably assign an assemblage of larval coregonines [Salmonidae Coregoninae] to shallow and multiple deepwater species. Larval coregonines from the Apostle Islands, Lake Superior, were genotyped using restriction site-associated DNA sequencing (RADseq) and were assigned to species using reference genotypes from adult corgonines from the same region. Of the 193 genotyped larvae, 101 were assigned as Coregonus artedi (average assignment probability = 97.6%), 57 were assigned as C. kiyi (average assignment probability = 95.5%), and 28 were assigned as C. hoyi (average assignment probability = 89.0%). Coregonus artedi were collected earliest in the season, followed by C. kiyi and then C. hoyi . Estimates of genetic diversity within each species provide a baseline for future monitoring in the Apostle Islands. Our success with species assignment indicates the promise of leveraging genomic data for larval coregonine identification, which could enable assessing and evaluating early life history dynamics and recruitment processes at the species level to the benefit of ongoing coregonine restoration and management efforts.

Wisconsin↗