Marine protected areas (MPAs) are a source of pride, ire and debate in coastal communities the world over.

Later this year, NOAA fisheries and the New England Fishery Management Council will make an important decision about MPAs in New England. It has been 16 years since NOAA and the council established fisheries habitat protection areas in our region as required by federal law. After ten years of research, planning and negotiation, decisions will be made this fall about the future of these areas.

A public comment period will open this fall to inform decisions about whether current MPAs will stay or go, and whether new ones will be established.

So, are MPAs working? Could they be improved? What have we learned by studying the environment and organisms inside and outside our local MPAs? Or MPAs around the world?

Long story short, it is complicated.

The complication arises from the variety of MPAs and the wide range of management measures they use. MPAs range in size from a few square miles to thousands of square miles. They are designated for all types of resource protection purposes: cultural—like shipwrecks; natural resources—like marine mammal breeding areas; and resource extraction—like fisheries spawning protection areas. MPAs range from “no-go” or no-take areas (marine reserves) to multi-use areas with few restrictions. Some MPAs have been highly successful in meeting locally defined goals for which they were designed. Others have not.

Whether MPAs help fisheries management has been particularly complicated and controversial.

Globally, there has been a fair amount of experience with marine protected areas. In a recent paper published in the scientific journal Nature, Graham Edgars and 24 co-authors analyzed research conducted at 87 marine protected areas around the world. Their results provide important insight for the decisions we face today in our region. They compared data collected via dive surveys inside and outside MPAs to compare key ecological factors—including the number and biomass of species—with a focus on large fish.

They identified five features of MPAs that correlated with more fish, particularly larger fish: no-take, well-enforced, ten-plus years as a protected area, those larger than 100 square kilometers and those isolated by deep water or sand. MPAs with three or more of these features saw increases. MPAs with only one or two of these features were “ecologically indistinguishable” from unprotected areas.

NOAA fisheries is one of several federal agencies that establishes and enforces MPAs. By far the most restrictive marine protected areas in our region are the fisheries habitat protection areas established in 1998. These relatively large areas on George’s Bank, in the western Gulf of Maine, and south of Cape Cod were originally created to help struggling populations of ground fish rebuild, and were later designated as habitat protection areas. Because the intention was to protect the sea floor habitat, some fishing gear has been banned in these areas, while other fishing has been allowed, including herring, lobster and fishing for groundfish recreationally and under special fishery access programs.

A few of the current fisheries habitat MPAs come close to meeting the characteristics identified as working, but we do not have any areas in New England that are closed to all types of fishing, so none are “no-take.” With four of the five identified characteristics, the global study indicates these areas would be likely to see increased biomass of large fish.

Have they led to such increases? A number of studies looked at the differences inside and outside the protected areas in our region. Researchers towed underwater cameras, conducted experimental fish sampling and surveys via scuba diving, and mapped the seafloor with high-resolution sonar and documented substantial differences. Underwater video and still photographs show a rich array of seafloor organisms, such as seapens, soft corals and tubeworms, creating complex sea floor habitat within the habitat protection areas. By comparison, areas of similar bottom outside the protected areas contain many fewer habitat forming organisms. Fish collection studies also show the size and number of some commercially fished species are larger within protected areas.

So what do we do next? What will we decide to do about these MPAs? NOAA and the council face difficult decisions about whether to continue protection and are looking for public input this fall. 

Dr. Heather Deese is an oceanographer and the Island Institute’s vice-president for strategic development. Dr. Susie Arnold is an ecologist and marine scientist with the organization.