Complex-Systems Approach to Simulating the Sea Urchin Ecology

Stocks of the native sea urchin (Strongylocentrotus droebachiensis) dropped dramatically during the peak of the urchin fishery in the early 1990’s and have not recovered. The current regulatory regime is based on analytic population models and two monolithic zones. Analytic models are insufficiently complex to capture many features that cause demise or survival of an urchin population. Scale, or granularity size, is too coarse. In contrast, a complex-systems-based model is able to capture these features. Presented here is a fine-scale simulation of a sea urchin fishery in the Gulf of Maine which behaves like a complex system, i.e. exhibits patchiness and nonlinear dynamics. Also presented is an alternative harvesting scheme which fosters sustainability. The model presented here is merely a hypothesis. Its predictions may not be verifiable until it either (1) becomes a part of a larger project, or (2) is paired with fine-scale data