Scientific Consensus Statement on Marine Reserves and Marine Protected Areas

At the 1997 Annual Meeting of the American Association for the Advancement of Science (AAAS), a symposium on marine protected areas reviewed the state of the oceans, raised a number of unresolved critical scientific issues and identified research priorities. In response, an international team of scientists was convened at the National Center for Ecological Analysis and Synthesis (NCEAS) and charged with developing better scientific understanding of marine protected areas and marine reserves.Conclusions from the two-and-a-half-year efforts of this working group are in press in a special issue of the journal Ecological Applications. This Scientific Consensus Statement is based upon those results and other research already published elsewhere. The Statement is a joint effort of the NCEAS scientists and the academic scientists participating in a meeting on marine reserves convened by COMPASS (Communication Partnership for Science and the Sea). This Statement was drafted in response to repeated requests by many fishermen, marine resource managers, governmental officials, conservation activists, interested citizens and others for a succinct, non-technical but scientifically accurate summary of the current scientific knowledge about marine reserves. Additional information on the history of this Statement, NCEAS and COMPASS appears after the Statement.

New Approaches Are Needed:

The declining state of the oceans and the collapse of many fisheries have created a critical need for new and more effective management of marine biodiversity, populations of exploited species and overall health of the oceans.Marine reserves are a highly effective but under-appreciated and under-utilized tool that can help alleviate many of these problems.At present, less than 1% of United States territorial waters and less than 1% of the world’s oceans are protected in reserves.

What are Marine Reserves?

Marine Reserves (MRVs) are areas of the sea completely protected from all extractive activities.Within a reserve, all biological resources are protected through prohibitions on fishing and the removal or disturbance of any living or non-living marine resource, except as necessary for monitoring or research to evaluate reserve effectiveness.Marine reserves are sometimes called “ecological reserves,” “fully-protected marine reserves,” or “no-take areas.”MRVs are a special category of Marine Protected Areas (MPAs).MPAs are areas designated to enhance conservation of marine resources.The actual level of protection within MPAs varies considerably; most allow some extractive activities such as fishing, while prohibiting others such as drilling for oil or gas.A Network of Marine Reserves is a set of MRVs within a biogeographic region, connected by larval dispersal and juvenile or adult migration.

The first formal marine reserves were established more than two decades ago.

Recent analyses of the changes occurring within these MRVs allow us to make the following conclusions:

Ecological effects within reserve boundaries:

1. Reserves result in long-lasting and often rapid increases in the abundance, diversity and productivity of marine organisms.

2. These changes are due to decreased mortality, decreased habitat destruction and to indirect ecosystem effects.

3. Reserves reduce the probability of extinction for marine species resident within them.

4. Increased reserve size results in increased benefits, but even small reserves have positive effects.

5. Full protection (which usually requires adequate enforcement and public involvement) is critical to achieve this full range of benefits.Marine protected areas do not provide the same benefits as marine reserves.

Ecological effects outside reserve boundaries:

1. In the few studies that have examined spillover effects, the size and abundance of exploited species increase in areas adjacent to reserves.

2. There is increasing evidence that reserves replenish populations regionally via larval export.

Ecological effects of reserve networks:

1. There is increasing evidence that a network of reserves buffers against the vagaries of environmental variability and provides significantly greater protection for marine communities than a single reserve.

2. An effective network needs to span large geographic distances and encompass a substantial area to protect against catastrophes and provide a stable platform for the long-term persistence of marine communities.

• Reserves conserve both fisheries and biodiversity.

• To meet goals for fisheries and biodiversity conservation, reserves must encompass the diversity of marine habitats.

• Reserves are the best way to protect resident species and provide heritage protection to important habitats.

• Reserves must be established and operated in the context of other management tools.

• Reserves need a dedicated program to monitor and evaluate their impacts both within and outside their boundaries.

• Reserves provide a critical benchmark for the evaluation of threats to ocean communities.

• Networks of reserves will be necessary for long-term fishery and conservation benefits.

• Existing scientific information justifies the immediate application of fully protected marine reserves as a central management tool.