Time series effects of dissolved oxygen and nitrogen on Long Island Sound lobster harvest

Abstract

The formation of hypoxic water zones in marine ecosystems across the world is a growing concern among marine scientists and regulatory agencies that focus on marine resource management. In the United States, a number of water systems such as the Gulf of Mexico, Long Island Sound, and the Chesapeake Bay experience hypoxic conditions annually. Nutrient rich water with excessive nitrogen content is widely recognized as a key anthropogenic cause that lead to development of hypoxic zones. While the dissolved oxygen level indicates the presence of hypoxic water conditions, at any given time, the aquatic nitrogen concentration indicates the possibility of formation of hypoxic zones in future time periods. Hence, understanding the effects of both these variables on current and future fish population is important for improved water quality management and sustainability of marine resources. In this paper, we estimate the temporal effects of these two key variables on lobster harvest from three contiguous fishing zones in the Long Island Sound that vary in ambient water quality. We find there is no contemporaneous effect of these variables on harvest in both the zone that experience hypoxia and the two zone that do not. While there is some evidence of lagged effects of these variables on harvest, no systematic pattern emerges in these effects that distinguishes the hypoxic fishing zone with non-hypoxic zones.