Gulf of Maine, New England, USA

• Marine protected areas that prohibit bottom fishing, such as the closures in the Gulf of Maine, can have positive effects on target species. 
• Fishing boats have concentrated their effort along the borders of closed areas in the Gulf of Maine, attracted by spillover and higher catches of bottom-dwelling fishes.
• 42% of the U.S. catch of haddock was taken within 0.6 miles of the closed areas.
• Inside the closed areas on Georges Bank, the number of scallops increased 25 times by 2003 and was 4 to 5 times greater than in fully fished areas outside. 

Replenishment of Bottom-dwelling Fishes

For centuries, the Gulf of Maine has been among the world's premier fishing grounds. By the early 1990s, however, catches of cod and other bottom-dwelling fishes had decreased dramatically. In response, fisheries managers closed 5 areas to any gear capable of catching bottom fishes: 3 areas on Georges Bank along the southern edge of the Gulf of Maine (1994), the western Gulf of Maine closed area (1996), and the central Gulf of Maine closed area (1998).

These areas are not marine reserves because they do not exclude all types of fishing. However, these areas have been closed to some types of fishing for a decade, offering a unique opportunity for scientists to study them and learn how closed areas may benefit target species. 

Scientists found that some bottom-dwelling fish species have increased in biomass inside the closed areas and are spilling over into surrounding waters. Now fishing boats concentrate along the closure edges, where catch rates of haddock and yellowtail flounder are higher. From 2001 to 2003, 42% of the total U.S. haddock catch was taken within 0.6 miles of the Gulf of Maine closed areas, and 73% was caught within 3.1 miles.

Rapid Increases in Scallops

Scallops have increased dramatically inside the Georges Bank closed areas along the southern edge of the Gulf of Maine. In 2003, scallop biomass inside the closures reached 25 times the pre-closure biomass. When compared to fully fished areas outside, biomass was 4 to 5 times greater inside the closed areas a decade after the protection began. However, the number of young scallops has fluctuated on Georges Bank, both inside and outside the closed areas. Scientists are still developing techniques to track the movements of these young scallops. It is not yet certain that offspring of the large, abundant scallops inside the closed areas are sustaining scallop fishing outside.

Choose another case study

1. Link J, et al. (2005) American Fisheries Society Symposium 41:345-368

2. Murawski SA, et al. (2005) ICES Journal of Marine Science 62:1150-1167

3. Murawski SA, et al. (2000) Bulletin of Marine Science 66:775-798

4. Hart DR, Rago PJ (2006) North American Journal of Fisheries Management 26:490-501

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