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Jason M. Robinson

Publications and source records attributed to Jason M. Robinson.

4 recordsLinked to original sources

Mixed-stock analysis in the age of genomics: Rapture genotyping enables evaluation of stock-specific exploitation in a freshwater fish population with weak genetic structure

Mixed-stock analyses using genetic markers have informed fisheries management in cases where strong genetic differentiation occurs among local spawning populations, yet many fisheries are supported by multiple spawning stocks that are weakly differentiated. Freshwater fisheries exemplify this problem, with many harvested populations supported by multiple stocks of young evolutionary age and that are isolated across small spatial scales. As a result, attempts to conduct genetic mixed-stock analyses of inland fisheries have often been unsuccessful. Advances in genomic sequencing now offer the ability to discriminate among populations with weak population structure, by providing the necessary resolution to conduct mixed-stock assignment among previously indistinguishable stocks. We demonstrate the use of genomic data to conduct a mixed-stock analysis of Lake Erie's commercial and recreational walleye (Sander vitreus) fisheries and estimate the relative harvest of weakly differentiated stocks (pairwise FST < 0.01). We used RAD-capture (Rapture) to sequence and genotype individuals at 12,081 loci that had been previously determined to be capable of discriminating between western and eastern basin stocks with 95% reassignment accuracy. An outcome not possible in the past with microsatellite markers. Genetic assignment of 1,075 fish harvested from recreational and commercial fisheries in the eastern basin indicated that western basin stocks constituted the majority of individuals harvested during peak walleye fishing season (July – September). Composition of harvest changed seasonally, with eastern basin fish comprising much of the early season harvest (May – June). Clear spatial structure in stock-specific harvest existed; more easterly sites contained more individuals of east basin origin than did westerly sites. Our study provides important stock contribution estimates for Lake Erie fishery management and demonstrates the power of genomic data to facilitate mixed-stock analysis in exploited fish populations with weak population structure or limited existing genetic resources.

Michigan, New York, Ohio, Pennsylvania

Tradeoff between assessment and control of aquatic invasive species: A case study of sea lamprey management in the St. Marys River

Allocating resources between the gathering of information to guide management actions and implementing those actions presents an inherent tradeoff. This tradeoff is evident for control of the Sea Lamprey Petromyzon marinus in the St. Marys River, connecting Lakes Huron and Superior and a major source of parasitic Sea Lampreys to Lake Huron and northern Lake Michigan. Larval Sea Lampreys in the St. Marys River are controlled through the application of Bayluscide, which is applied to areas of high larval density. Bayluscide applications are guided with an annual deepwater electrofishing survey to estimate larval Sea Lamprey density at relatively fine spatial scales. We took a resampling approach to describe the effect of sampling intensity on the success of the larval Sea Lamprey management program and explicitly incorporated the economic tradeoff between assessment and control efforts to maximize numbers of larvae killed in the St. Marys River. When no tradeoff between assessment and control was incorporated, increasing assessment always led to more larvae killed for the same treatment budget. When the tradeoff was incorporated, the sampling intensity that maximized the number of larvae killed depended on the overall budget available. Increased sampling intensities maximized effectiveness under medium to large budgets (US \$0.4 to \$2.0 million), and intermediate sampling intensities maximized effectiveness under low budgets. Sea Lamprey control actions based on assessment information outperformed those that were implemented with no assessment under all budget scenarios.

St. Marys River

Comparing methods for estimating larval sea lamprey ( Petromyzon marinus ) density in the St. Marys River for the purposes of control

The St. Marys River is a major producer of parasitic sea lampreys ( Petromyzon marinus ) to Lake Huron making it an important area for larval control. Bayluscide treatments are conducted in areas of high larval density requiring density estimation at fine spatial scales to inform treatment decisions. We evaluated six methods of estimating spatially specific density including the currently used sampling-based estimates, a generalized linear model (GLM) based on mean larval density per plot, a GLM based on larval density per sample, a generalized additive model based on mean larval density per plot, a spatial age-structured population model, and a hybrid approach, which averaged the best performing sampling- and model-based methods. Methods were evaluated based on accuracy in matching independent validation data. Specifically, the methods were evaluated based on their ability to project plot-level larval density, identify high density plots for treatment, and rank plots in order based on density resulting in high numbers of sea lampreys killed per hectare treated. Performance was variable, and no single method outperformed the others for all metrics. Although the sampling-based estimation method and the GLM based on catch data performed adequately for estimating density and identifying high density plots, the hybrid approach was identified as the best method to inform sea lamprey control decisions in the St. Marys River due to its consistent performance. Incorporating model-based approaches should lead to a more efficient and effective treatment program in the St. Marys River and aid in making decisions about the allocation of control resources.

St. Marys River

A spatial age-structured model for describing sea lamprey ( Petromyzon marinus ) population dynamics

The control of invasive sea lampreys ( Petromyzon marinus ) presents large scale management challenges in the Laurentian Great Lakes. No modeling approach has been developed that describes spatial dynamics of lamprey populations. We developed and validated a spatial and age-structured model and applied it to a sea lamprey population in a large river in the Great Lakes basin. We considered 75 discrete spatial areas, included a stock-recruitment function, spatial recruitment patterns, natural mortality, chemical treatment mortality, and larval metamorphosis. Recruitment was variable, and an upstream shift in recruitment location was observed over time. From 1993–2011 recruitment, larval abundance, and the abundance of metamorphosing individuals decreased by 80, 84, and 86%, respectively. The model successfully identified areas of high larval abundance and showed that areas of low larval density contribute significantly to the population. Estimated treatment mortality was less than expected but had a large population-level impact. The results and general approach of this work have applications for sea lamprey control throughout the Great Lakes and for the restoration and conservation of native lamprey species globally.

Great Lakes