Spatial Changes in the California Groundfish Trawl Fishery 1997 to 2009

Changes in the distribution and intensity of trawling over the past 13 years in the multispecies groundfish trawl fishery, are analyzed here.  Although the extent of trawling in northern California has changed little in that time, the distribution of effort within the area has shifted, mostly into deeper water.  These changes can be traced to a number of management measures made in response to the declaration between 1999 and 2002 of eight groundfish species as overfished. 

Spatial closures, trawl gear restrictions, and differential species landings limits, for different trawl gears and for different depths, have been used together to redirect effort away from areas with overfished species.  In addition, the fleet size was reduced by one third through a buyback program at the end of 2003. 

The trawl Rockfish Conservation Areas are gear specific depth-based closures along the shelf break of the entire west coast.  The dimensions of the trawl closure are dynamic, changing between and within years.  They are set to protect the various overfished species found at different depths along the coast.  Some of the overfished species occur primarily on the middle shelf whereas others occur on the outer shelf and upper slope making it hard to craft a “one size fits all” closure. 

Closures were expanded whenever bycatch of an overfished species threatened to exceed the annual Optimal Yield set by its rebuilding plan.  Closures have been reduced to facilitate fishing for other more abundant species, when the bycatch of overfished species stayed within bounds.  Observers were placed on about 20% of the trawl vessels to monitor the bycatch rates of overfished species.

The trawl fishery is just one of several fisheries, including commercial and recreational hook and line fisheries, that catch some of the overfished species. Despite management coordination by the Council, the sectors have not had separate allocations, so a high catch rate in another sector has often affected the trawl fishery.

After much planning, the trawl fishery has changed to a catch share program with sector allocation in 2011.  Some management measures, such as most trip limits, have been removed, but Rockfish Conservation Areas will remain for now to provide sufficient protection for the rebuilding of overfished species.  This poster relates changes in distribution of trawl catch and effort to changes in regulations before the implementation of the catch share plan.