Analysis

In the Northeast Multispecies Fishery, vessels fish primarily with otter trawls, sink gillnets, bottom longline (tub trawls), jigs, and handlines. Bottom trawling with otter trawls is the predominant fishing method employed, although many vessels participating in the groundfish fishery switch gears seasonally. Bottom trawling can alter seabed habitat, change biological communities that live within that habitat, and change sediment composition.  Because catch shares might alter the spatial pattern of fishing, and because habitat sensitivity to trawling varies considerably, it is possible that shifts in fishing effort could alter habitat impacts.

To measure a shift in habitat vulnerability related to the catch share program, we would need to understand fine-scale geographic patterns of fishing activity, along with information on types of gear that were used, the footprints of those gears, and the sensitivity of seabed habitats in different areas. The New England Fishery Management Council worked with a wide range of experts to create a Swept Area Seabed Impacts model that can be used to judge the vulnerability of seabed habitats to fishing. However, fine-scale information on fishing locations was not available because vessel monitoring system (VMS) data alone do not reliably indicate when fishing was occurring.

In the future, detailed analysis of VMS data along with vessel trip reports could be used to document the spatial footprint of groundfish trawling and how it may have changed after implementation of the catch share program. Once that analysis is in hand, the Swept Area Seabed Impacts model could be applied to judge shifts in habitat vulnerability.

Updated: August 2018