WASHINGTON (Saving Seafood) 18 March 2013 — After nearly 20 years, there is little evidence that the habitat area closures off the New England coast benefit groundfish stocks. In addition, recent seabed mapping suggests that they are not even in locations best suited for habitat protection. Yet, the Sylvia Earle Alliance’s web-story, “New England Fisheries Face Serious Setbacks (2/27),” misleads readers with the argument that the New England Fishery Management Council’s (NEFMC) proposals to change the closures puts New England’s Georges Bank seabed “at risk of serious ecological setback,” when multiple studies prove otherwise.
The Council’s proposed Omnibus Amendment, which recommends changing access to these New England closures, was developed using advice from their Habitat Plan Development Team (PDT), which determined that keeping the locations closed to fishing is ultimately more detrimental to the New England seabed.
Academic sources used in the preparation of this response are linked throughout and listed in the bibliography at the end of this story.
The Truth About Trawling In New England
The Alliance’s allegations about the ecological effects of trawling in New England do not appear to be informed by relevant scientific findings.
A significant portion of the Georges Bank seabed is a sandy, soft-bottom ecosystem. This type of benthic environment shifts frequently due to strong tidal changes and storms. These areas are considered “highly dynamic,” meaning that they are accustomed to natural disturbances. A 2012 study by scientists from the Alaska Pacific University and the School of Marine Science and Technology (SMAST) at the University of Massachusetts Dartmouth found that tidal forces were strong enough to shift seafloor habitats every two weeks. Much of Georges Bank is subject to tidal forces so strong (roughly equivalent to or greater than 70 mph winds on land*) and shifts so much that very little permanent life can grow.
Multiple studies demonstrate that trawling in dynamic environments has minimal effects on the seabed’s ecosystem and productivity. A 2001-2002 federal survey evaluating the effects of trawls on soft-bottom New England habitat concluded that the effects of trawls were comparable to the effects of natural disturbances. The study found no great ecological difference between seabeds in areas that have been trawled for over 50 years and areas that have only been disturbed by natural events. A later 2006 academic study reached a similar conclusion about the effects of trawling on Georges Bank, concluding that a “short-term sea scallop fishery” alters the environment “less than the natural dynamic environmental conditions of Georges Bank.”
Managing Our Management
The Council’s recommendations are mislabeled by the Alliance as “shortsided,” when, in fact, the proposal attempts to increase overall habitat protection by accounting for new management practices and updated science.
In 2010, the Northeast abandoned a system of effort controls — which managed the fishery by limiting when, where, and how fishermen could fish — and switched to allocation-based management. Under this new regulatory system, only a pre-determined quota of fish can be taken from the ocean.
Currently, large areas of the closures remain as vestiges of the outdated effort controls from the early 1990s. This creates complications when managed alongside the new allocation system. By excluding fishermen from productive fishing grounds, these effort controls force fishermen to increase their overall fishing efforts to reach quota, ultimately affecting more habitat.
The comprehensive analysis backing the Amendment concludes that opening areas of the outdated closures to commercial fishing — including trawling — will minimize total adverse effects:
“We find that for nearly all area and gear type combinations, opening existing closed areas to fishing is predicted to decrease aggregate adverse effects. For mobile bottom tending gears, which comprise nearly 99% of all adverse effects in our region, allowing fishing in almost any portion of the area closures on Georges Bank is estimated to substantially decrease total adverse effects from fishing.” (pg. 16)
This analysis has been praised by the NEFMC’s Science and Statistical Committee.
Research Transformed Into Action
Since the late 1990s, when habitat areas considered important to groundfish were closed as part of the Magnuson-Steven Fishery Conservation and Management Act, the science behind the boundaries has become outdated. When the areas were designated, scientists had limited information (charts with over 100 hand-drawn habitat samples compared to the 70,000 video sample points from a ten-year study available today) about the New England seabed. The areas were chosen based largely on the locations of the previous effort control closures from earlier in the decade that were intended to limit fishing ability, not protect specialized habitat.
This ten-year study, which between 1999-2009 mapped the Georges Bank seabed using underwater video, indicated that the current closures are not in locations that would best protect important habitats. The closure boundaries appear to be geographically arbitrary and do not include many of the rocky habitats that are most susceptible to fishing disturbances. These rocky areas are also most likely to harbor juvenile groundfish and feature unique habitats. This creates a no-win situation for both the fishermen and the fish.
*70mph winds are the rough equivalent to the 1 newton-per-meter-squared amount of force the seabed faces twice a month.
Read the full story from the Sylvia Earle Alliance
Bibliography
Harris, Bradley; Cowles, Geoffrey; Stokesbury, Kevin, “Surficial sediment stability on Georges Bank, in the Great South Channel and on eastern Nantucket Shoals,” Continental Shelf Research, Volume 49, September 23, 2012, p. 65-72
Harris, Bradley; Stokesbury, Kevin, “The spatial structure of local surficial sediment characteristics on Georges Bank, USA,” Continental Shelf Research, Volume 30, Issue 17, October 15, 2010, p. 1840–1853
NOAA/NMFS Unallied Science Project, Cooperative Agreement, "Bottom Net Trawl Fishing Gear Effect on the Seabed: Investigation of Temporal and Cumulative Effects,” December 2005
Stokesbury, Kevin; Harris, Bradley, “Impact of limited short-term sea scallop fishery on epibenthic community of Georges Bank closed areas,” Marine Ecology Progress Series, Volume 307, January 24, 2006, p. 85-100