Life Sciences Commons^™

Evaluation Of The Effectiveness Of Ventless Trap Survey In Capturing Sublegal American Lobster Abundance In The Inshore Gulf Of Maine, Shiyue Zhao

Electronic Theses and Dissertations

The stock assessment of American lobster (Homarus americanus) plays an important role in managing the fishery in the Gulf of Maine (GOM). Various fishery-dependent and fishery-independent data are required in the stock assessment to estimate key fisheries parameters that define the population dynamics of American lobster. In the 2015 benchmark stock assessment, ventless trap survey (VTS) data were included for the first time to provide information about the sublegal lobster (carapace length < 83 mm) dynamics. However, the effectiveness of VTS data in monitoring sublegal lobsters has not been evaluated and we have little information on whether the VTS sampling design can capture sublegal lobster dynamics. The primary goal of this thesis research was to evaluate and determine whether the data collected from the Maine VTS provide robust estimation of design-based sublegal lobsters abundance index in the inshore GOM. To achieve this goal, I (1) estimated and evaluated variations in catch rates derived, respectively, from the first, second, and third ventless trap per site; 2) predicted sublegal lobster population at a high spatial resolution using generalized additive models (GAMs); (3) sampled the simulated sublegal lobster population following the sampling protocol used in the VTS program to derive a simulated VTS abundance index; and 4) compared the simulated VTS abundance index with the

predicted population abundance index in the simulated sublegal lobster population. The spatial scale of the study was defined by the National Marine Fisheries Service (NMFS) statistical areas in …

The Impacts Of Climate Change On The Gulf Of Maine Northern Shrimp (Pandalus Borealis) Distribution, Reproduction, And Life, Hsiao-Yun Chang

Electronic Theses and Dissertations

The Gulf of Maine northern shrimp (Pandalus borealis) once supported a significant winter fishery for the Gulf of Maine (GOM). Although the shrimp fishery is not comparable to the lobster business, it provided fishermen and many coastal communities jobs and incomes in winters after lobster seasons. However, a moratorium has been put on the shrimp fishery since 2014 due to record low population abundance and perceived recruitment failures. The recruitment failures have been correlated with warming water temperatures over the past decade. The GOM has been recognized as experiencing rapid warming as a result of global climate change. …