Estimation of the Magnitude and Distribution of Fishing Effort in the Gulf of Mexico Shrimp Fishery

Revised estimates of offshore fishing effort (nominal days fished) for the Gulf of Mexico penaeid shrimp trawl fishery are provided for the period of record, 1960 to 2009. The revised estimates are based on a pooled approach and take changes in the fishery, changes in data collection and management approaches, and advancements in technology into account. Within year, effort is estimated for three trimesters (January-April, May-August, September-December) and, within trimester, for four regions (Statistical Areas 1-9, 10-12, 13-17, and 18-21).  Each region is subdivided into three depth zones (0-10 fathoms,>10 to 30 fathoms, > 30 fathoms). This approach requires data for 36 time/space cells as compared to 2,628 cells requiring data in the historical approach. Offshore effort levels were low in the 1960’s (~ 118,000 nominal days fished) but increased to levels on the order of 200,000 nominal days fished by the late 1970’s.  Offshore effort remained high and relatively stable from this time through about 2002, but plummeted over the period 2003-2009.