Though “marine conservation” feels like a recent concept, the protection of coastal and ocean ecosystems can be traced far back in humanity’s history. Many island societies, such as those of Palau, had the notion of personal stewardship of the ocean incorporated into their beliefs and daily practices^[1]Wells, S. et al. Building the future of MPAs – lessons from history: Building the Future of MPAs. Aquat. Conserv. Mar. Freshw. Ecosyst. 26, 101–125 (2016).. They could impose a temporary ban on the take of certain fish species that became scarce. Historical records from the 9th century indicate that community elders in Madagascar were similarly responsible for overseeing the management of marine resources in their territories^[2]Rakotoson, L. R. & Tanner, K. Community-based governance of coastal zone and marine resources in Madagascar. Ocean Coast. Manag. 49, 855–872 (2006).. Although modern marine protections may be operationally different, they have the same ideological foundation, which recognizes the ocean as a source of life and prosperity that is worthy of preservation and respect.

What are MPAs?  

The term “Marine Protected Area” is credited to the International Union for Conservation of Nature (IUCN) during their 1962 World Congress on National Parks, and was largely inspired by protected intertidal habitats in Australia, South Africa, and Malaysia^[3]Humphreys, J. & Clark, R. W. E. Chapter 1 – A critical history of marine protected areas. in Marine Protected Areas (eds. Humphreys, J. & Clark, R. W. E.) 1–12 (Elsevier, 2020). … Continue reading. A handful of definitions exist, but NOAA’s classification of them as “regions designated and managed for the long-term conservation of marine resources, ecosystem services, or cultural heritage^[4]What is a marine protected area (MPA)? : Ocean Exploration Facts: NOAA Office of Ocean Exploration and Research. https://oceanexplorer.noaa.gov/facts/mpas.html..”

It is thought the first MPAs arose from traditions in Australia, South Africa, and Malaysia that protected intertidal habitats for wildlife in the 19th century^[5]Wells, S. et al. Building the future of MPAs – lessons from history: Building the Future of MPAs. Aquat. Conserv. Mar. Freshw. Ecosyst. 26, 101–125 (2016).. 

MPA’s Around the World

MPAs are not uniform in their protections: the level and nature of restrictions depend on local laws, policies, and objectives . Of course, there are several systems to categorize MPAs.  Protected Planet, a database of marine protected areas, has a straightforward system that sorts them into three categories^[6]The MPA Guide. https://mpa-guide.protectedplanet.net/explore/levels-of-protection/by-level.:

• Minimally protected: though designated as an MPA, this category applies to areas that either allow some industrial activity or lack the enforcement or implementation (such as physical boundaries, education of the community/staff, etc.) needed. They usually allow recreation, but common restrictions include commercial fishing and the discharge of waste from ships. Some minimally protected MPAs include: Monterey Bay, CA and Cape Cod, MA^[7]MPA Guide Marine Protection. https://mpatlas.org/mpaguide/?. 
• Lightly protected: This category has a lot of variation, but mostly prohibits industrial activities like mining and drilling for oil, and can regulate the entry and movement of some vessels like cruise ships or large fishing trawlers. In many cases, lightly protected MPAs allow commercial fishing, but regulation is variable and dependent on the area. Some examples: Great Barrier Reef in Australia and the Everglades in Florida^[8]MPA Guide Marine Protection. https://mpatlas.org/mpaguide/?. 
• Highly/Fully protected: As the name suggests, these MPAs have heavy restrictions in place, and minimal, if any, resource extraction (such as fishing, hunting, seabed mining, and oil drilling) is allowed. These often are “no-take” reserves, meaning no or very limited fishing is allowed. Examples include: Palau and Marianas Trench^[9]MPA Guide Marine Protection. https://mpatlas.org/mpaguide/?.

Other iconic MPAs include the Florida Keys, U.S.A., the Galapagos Islands, Ecuador, and the Cook Islands. To explore the full extent of the world’s marine protected areas, check out the Marine Protected Area Atlas, a database launched in 2012 by the Ocean Conservation Institute^[10]Marine Protection Atlas » Marine Conservation Institute. Marine Conservation Institute https://marine-conservation.org/mpatlas/..

 Figure 1: Map of global marine fishing protection^[11]Marine Protection Atlas » Marine Conservation Institute. Marine Conservation Institute https://marine-conservation.org/mpatlas/..

Where Do They Work and Where Do They Fall Short?

The benefits of being a highly protected marine area are significant. One study conducted in 124 fully protected, “no-take” marine reserves in 29 countries reported an average average increase in biomass (organic material) of 400%^[12]Lester, S. E. et al. Biological effects within no-take marine reserves: a global synthesis. Mar. Ecol. Prog. Ser. 384, 33–46 (2009).. MPAs also increase resilience to dramatic climatic events, as the organism populations within them are typically more stable: they provide a safe space for populations to develop and recuperate when vulnerable, and eventually, they leave the reserve to repopulate other areas^[13]Micheli, F. et al. Evidence That Marine Reserves Enhance Resilience to Climatic Impacts. PLOS ONE 7, e40832 (2012).. Designating a space as a marine protected area also can prohibit damaging mining and oil extraction that can pollute the water and cause high mortality^[14]Earth Day: Upping Ocean Protection and Putting a Pause on Seabed Mining. Esri https://www.esri.com/about/newsroom/blog/upping-ocean-protection-pausing-seabed-mining/ (2022).. For example, the system of MPAs in California now takes up 16% of state waters and has noticeable results, sporting larger fish in greater numbers than in unprotected areas. The Channel Islands, CA have been protected for 10 years now and report recovery in overfished species, as well as a positive spillover effect, as the fish move out of the boundaries of the MPA into unprotected areas^[15]Monroe, R. Early Results Suggest California Marine Protected Areas are a Success. Scripps Institution of Oceanography … Continue reading. 

Marine protected areas, when managed, integrated, and enforced, are incredibly beneficial, but when they lack sufficient governmental support they can dramatically decrease in effectiveness. Over half of global MPAs are lacking in resources, training, and capacity, making their protections almost impossible to enforce^[16]Understanding Marine Protected Areas (MPAs) – WildAid Marine. https://marine.wildaid.org/understanding-marine-protected-areas-mpas/.. There is also a continued discussion on how to preserve vital ocean ecosystems while balancing the needs of the communities surrounding them. Highly protected areas may prove to be very beneficial in some cases, and others can end up as conflicting with local social or economic practices. Thus, management of marine reserves is a case-by-case process, tailored to work out trade-offs that minimize negative impacts. 

It is also important to address the migratory nature of most marine species. Many of the large macrofauna that benefit from the protection of MPAs easily move out of their bounds. Effective systems of MPAs are needed, establishing protection over key marine spaces and routes that are frequented by migratory species. In these cases, the total area of protected waters is less important than the location and shape. A study delineating a core corridor off of the Australian coast used by flatback turtles (Natator depressus) noted that the nationally protected coastal areas only covered 52% of their route. Other marine species such as humpback whales (Megaptera novaeangliae) (which overlapped by 96% with the turtles’ route) and 20 other marine vertebrates utilized the same corridor for their migration^[17]Pendoley, K. L., Schofield, G., Whittock, P. A., Ierodiaconou, D. & Hays, G. C. Protected species use of a coastal marine migratory corridor connecting marine protected areas. Mar. Biol. 161, … Continue reading. Protecting this stretch of about 31,000 square kilometers could have more significant impacts on the species than a series of separate, large reserves placed in less strategic locations. 

Current Events and Goals for the Future 

A variety of international agreements address and call for the establishment of more MPAs around the world. Notable among them are the Aichi Biodiversity Targets, more specifically target 11 which called for marine protections and conservation practices implemented in at least 10% of the world’s coastal and marine areas by 2020^[18]Unit, B. Aichi Biodiversity Targets. https://www.cbd.int/sp/targets/ (2020).. As of 2022, less than 8% of the world’s oceans are designated as marine protected areas. But, protections have shown to very quickly yield promising results once implemented, boasting increased fish stocks, more biodiversity, and overall survival of various organisms^[19]How Marine Protected Areas Help Fisheries and Ocean Ecosystems. Center for American Progress https://www.americanprogress.org/article/marine-protected-areas-help-fisheries-ocean-ecosystems/.. MPAs also play an integral part in the return of keystone species (one that has a significant effect on the abundance and health of the ecosystem) such as the southern sea otter (Enhydra lutris nereis) in Monterey Bay, California. Since the establishment of the Monterey Bay National Marine Sanctuary in 1995, the number of sea otters has increased by 25%^[20]MBNMS Site Characterization: Marine Mammals – IV. Sea otter. https://montereybay.noaa.gov/sitechar/mamm4.html., resulting in the regrowth of the native kelp forest ecosystem that had previously been overgrazed by purple sea urchins. It now continues to grow at a rate that has scientists hopeful for a full recovery of the ecosystem^[21]Stephens, T. Sea otters maintain remnants of healthy kelp forest amid sea urchin barrens. UC Santa Cruz News https://news.ucsc.edu/2021/03/kelp-forests-monterey.html.. 

The future of our world depends on the protection of our oceans, and the goals behind the Aichi Biodiversity Targets were on the right track. World leaders have started to set goals for their countries, such as President Biden’s move for 30 by 30, which aims to to conserve 30% of terrestrial and marine regions in the United States^[22]Cayton, H. What is 30×30? Conservation Corridor https://conservationcorridor.org/what-is-30×30/.. This policy follows the entry of the U.S. into an agreement of 17 countries that have committed to 100% sustainable management of marine areas under their jurisdiction by 2025, as well as the 30% protection goal^[23]The Agenda. WRI Ocean Panel https://oceanpanel.org/the-agenda/.. These include Canada, Fiji, Japan, Kenya, Australia, and Indonesia (for the full list, check it out here). 

 As the provisions to put in protections increase, the opportunity to conserve your local environment increases too! Local, community based management is the best strategy when it comes to the sustainability of protected areas. As a resident, be mindful of new local protocols, restrictions, or guidelines and as a tourist, practice respect and a ‘leave no trace’ approach. Individual action cannot be discounted in all of this, and know that your support and adaptability helps sustain our oceans and coasts for years to come.

Cate Hogan

Research and Writing Intern

Learn More About Cate