Biodiversity Biological oceanography Conservation Ecology Fisheries Human impacts

Marine Protected Areas need more than just a name

The Paper: GILL D.A., MASCIA M.B., AHMADIA G.N., GLEW L., LESTER S.E., BARNES M., CRAIGIE I., DARLING E.S., FREE C.M. & GELDMANN J. 2017. Capacity shortfalls hinder the performance of marine protected areas globally. Nature 543: 665-669.

Why the ocean needs our protection

The fact that you have taken an interest in this article, and in general, means you care about the ocean. You want to know more about the physical, chemical, biological, and geological processes that make this an ocean planet. You understand that without healthy oceans, we don’t have a healthy planet, and since we have nowhere else to go, our continued existence on this little blue marble is at risk.

Figure 1. Tuna at auction. Tuna are among the family Scombridae, which has declined nearly 75% since 1970. (source:

Nearly 60% of the world’s population (about 4.5 billion people) live within 60 miles (100 kilometers) of the ocean and 3 billion people rely on marine and freshwater fish as their primary source of protein. Additionally, 12% of the global population rely on fisheries as a livelihood, and this vital resource is under threat. A 2015 study by the World Wildlife Fund (WWF) (World Wide Fund for Nature in the UK) concluded that there has been a 49% global decline in populations of all marine species since 1970. This includes a 50% population reduction in all fish species where 29% of commercial fish stocks are classified as overexploited and 61% as fully exploited. Additionally, species in the family Scombridae (which includes tuna and mackerel) have declined nearly 75%!

It isn’t just fish that are affected. The ocean is a massive ecosystem that exists in delicate balance with all species, and actions that affect local populations can have a global impact. Fifty percent of the oxygen we breathe comes from the oceans, mostly from microscopic organisms called phytoplankton, and without the balance of nutrient cycling from all levels of organisms, these phytoplankton cannot survive. It is because of the biological depletion of the sea, and subsequent global impacts, that our oceans need our protection.

What is an MPA?

A Marine Protected Area (MPA) is a broad term used to describe any number of marine sanctuaries, estuarine research preserves, ocean parks, and marine wildlife refuges (Fig. 2). They are established and managed by all levels of government and may be used to protect ecosystems, preserve cultural heritage and archaeological sites, or to sustain fisheries. While some may think of an MPA only as a place where fishing is not allowed (no-take MPA), this is not the case. Only about 3% of US waters are no-take MPAs, or marine reserves, where the rules are in place to help a very damaged ecosystem return to normal or to protect rare organisms.

Figure 2. Marine Protected Areas of the United States. (source:

In the United States MPAs were expanded and strengthened by a presidential executive order in 2000 for the purpose of protecting “…the significant natural and cultural resources within the marine environment for the benefit of present and future generations.” In 2011, the International Convention on Biological Diversity set one of its strategic goals to conserve, through equitable and effective management, 10% of coastal and marine areas by 2020. This agreement was signed by 193 countries and further strengthened international MPAs. However, agreeing to fulfill this commitment and executing the plan are two very different things. Last month, an international group of investigators led by Dr. David Gill gathered information on these international MPAs to evaluate their impact and effectiveness.

The Study

Dr. Gill and his team collected management data from 433 MPAs and ecological data from 218 MPAs to “…document and examine linkages between MPA management processes and conservation outcomes.” These MPAs represent every tropical and temperate ocean basin and span diverse social, political, and biophysical regions. Once the data was collected, the researchers analyzed three main areas of interest: management effectiveness based on management and social theory, biological impacts by comparing data inside and outside the MPAs, and the relationship between management and ecological impacts.

Figure 3. Staff capacity data for 433 International Marine Protected Areas. (source: Gill et al., 2017)

Because of the rather loose definition of an MPA, it should be no surprise that one of the greatest inconsistencies across all MPAs is effective management. Of the 433 studied, only 79% were legally documented as an MPA and only 69% had regulations regarding resource use. Even more striking is that 65% of the MPAs reported that their budget could not support basic management and a whopping 91% reported that they were understaffed (Fig 3). Even in cases where there was full-time management, only 13% of the MPAs actively used scientific results as part of their management and policy decisions.

With regard to ecological impact, the results were a little brighter. On average, MPAs had a positive impact on fish biomass with a value 1.6 times higher than similar ecological areas not protected under an MPA. This assessment includes both the multi-use MPAs and the ones that prohibit removing wildlife (no-take), clearly showing that proper regulation can have a positive impact without the need for a moratorium on fishing (Fig. 4). When the researchers combined the management and ecological data, they found adequate staff capacity to be the main driver in MPA effectiveness with budget capacity coming in a close second. Fish biomass in MPAs with proper staffing and funding was 2.9 times higher than those without, showing that effective biodiversity is not simply a function of environment.

Figure 4. Biomass data for 218 International MPAs. Blue indicates positive impact. (source: Gill et al., 2017)

The Significance

Although steps such as the 2000 presidential executive order and the International Convention on Biological Diversity decision are heading in the right direction, it takes more than intent to effect change. Proper funding and management are the key drivers to not only sustain the ocean ecosystem, but to reverse many of the disastrous policies that have led us to this point. It takes people and resources to effectively support monitoring, enforcement, administration, community engagement, and sustainable tourism activities of the designated MPAs. A previous WWF study concluded that every dollar invested in MPAs could triple the benefits through employment, coastal protection, and fisheries with a return of between $490 billion and $920 billion over a period of 35 years. More importantly than the bottom line, the future habitation of our planet depends on the oceans and their resources, and without responsible stewardship, this cannot occur.

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