Investigating interconnected fisheries: a coupled model of the lobster and herring fisheries in New England

Abstract

Ostensibly separate fisheries are often linked through ecological, environmental, and human mediated processes that can impact their productivity, profitability, and resilience; however, managers rarely explicitly account for these linkages. We present a coupled bioeconomic model of the American lobster (Homarus americanus) and Atlantic herring (Clupea harengus) fisheries in the northeast United States. The model builds upon existing stock assessment models and includes key characteristics of both fisheries including size- or age-structured populations, seasonal patterns of lobster exploitation, and seasonal-spatial patterns of herring exploitation. The lobster and herring models are linked through a bait market module that drives behavior of the herring fleet and affects catches, costs, and revenues in both fisheries. The model illustrates how changes in management or ecosystem conditions in one fishery can propagate to another. The model suggests that the lobster fishery is robust to declines in herring recruitment and limited changes in the spatial allocation of the herring total allowable catch. However, herring catches and stocks are affected by changes in lobster management that impact effort levels.