Incorporating Environmental Variables to Improve Assessment and Predictive Capacity for American Lobster in a Changing Gulf of Maine and Southern New England

Yong Chen, Jie Cao and Kisei Tanaka School of Marine Sciences, University of Maine

Abstract

The American lobster, a bottom-dwelling crustacean distributed along the coast of northeastern United States, support the most valuable fishery in the USA. Many coastal communities heavily depend on the lobster fishery, leaving the coupled natural and human system vulnerable to environmental changes. Studies suggest that the population dynamics of American lobster experience strong bottom-up (e.g., climate and temperature) controls. For sustainable management of this species, it is critical to (1) evaluate the relative importance and synergistic impacts of these drivers, (2) maximize the efficiency and accuracy of the existing stock assessment program, and (3) develop the capacity for predicting spatio-temporal changes in the biogeography of lobster stock. This has become increasingly important because water temperatures in northeast USA have increased over the last 40 years and now seasonally exceeds the thermal tolerance of lobsters in some portions of SNE. As the rate of climate change is predicted to accelerate in the future, there is a growing need to assess changes in lobster habitat condition and consider them in stock assessment.
 
The overarching goal of this study is to develop a modeling framework that can improve our predictive capacity of lobster stock dynamics in an altered environment driven by climate change. To this end, the coupled biophysical modeling framework developed in the PI (Chen) Lab can provide ideal hind-, now-, and forecasting tools to study the impact of climate change on lobster population dynamics and phenology. Building on the previous work conducted in the Chen Lab, we want to achieve the following two specific objectives: Objective I: Project possible spatio-temporal changes in suitable habitat, molting and abundance of American lobster in changing SNE and GOM; Objective II: Incorporate key environmental variables into the lobster stock assessment model to better assess the SNE and GOM lobster stocks.
 
Our work will provide predictive capacity for improving our understanding of potential changes in the lobster biogeography and impacts on the lobster assessment and management to better deal with the uncertain future in the SNE and GOM ecosystems. The approach developed will be applicable to other fishery resources (e.g., Atlantic Sea Scallop) in this rapidly changing environment. This project addresses the following NOAA goals by incorporating temperature and predator abundance in the northern shrimp stock assessment: (1) Healthy Oceans: Marine fisheries, habitats, and biodiversity sustained within healthy and productive ecosystems; and (2). Climate Adaptation and Mitigation: An informed society anticipating and responding to climate and its impacts
 
We plan to complete the project in two years. We will finish the 1st objective in the first year and the 2nd objective in the 2nd year. In the 2nd year, we will also prepare all the software and data to incorporate the results derived in this study in the next lobster stock assessment.