Analysis of harbor porpoise gillnet bycatch, compliance, and enforcement trends in the US northwestern Atlantic, January 1999 to May 2010

Abstract

In 1999 the US National Marine Fisheries Service (NMFS) implemented regulations to limit harbor porpoise Phocoena phocoena incidental bycatch in US waters of the northwestern Atlantic. This effort was called the Harbor Porpoise Take Reduction Plan (HPTRP) and included a mixture of time-area closures, pinger and other gear modification requirements, a pinger training program, and outreach and education efforts. This paper focuses on the plan from January 1999 to May 2010 and examines trends in bycatch patterns, compliance with the plan, enforcement of the plan requirements, and changes in the primary fisheries involved in harbor porpoise bycatch. Over the course of the plan harbor porpoise bycatch dropped in the first few years, increased to unacceptable levels during the middle years, and moderated in the later years of the plan. Changes in fishing effort and distribution of key fisheries played a large role in decreasing the bycatch in much of the Mid-Atlantic and also in increasing bycatch in Southern New England and off the coast of New Jersey. The pattern in compliance levels had an inverse relationship with bycatch levels, with better compliance and lower bycatch in early and late years, though compli- ance was generally poor even when at its best. Enforcement of HPTRP regulations was not well documented, but, from available compliance data, it appears that what enforcement did occur was not sufficient to improve compliance. Given poor compliance with pinger requirements, these requirements have not resulted in the expected reduction in bycatch.