Marine Protected Areas (MPAs) can be valuable tools for ocean conservation; however, they are not a cure-all, and, in some cases, they can have far ranging negative effects. 

Calls to lock up 30 percent of the ocean by 2030 make a good slogan, but would doing that actually be beneficial for the environment? 

MPAs come in all sizes and in various degrees of conservation. There are small or large coastal MPAs, and there are closures of very big tracts of ocean that are called Large Open Ocean MPAs, or LOOMPAS. 

Let’s bust some myths on MPAs. 

Myth: The more open ocean you prevent any fishing in, the better for the planet. 

Fact: LOOMPAS are indiscriminate closures of ocean based on square kilometres, or a percentage of the world’s whole ocean area, as opposed to closures to protect specific marine life. Closing such a large area to any fishing just moves fishing to adjacent parts of the ocean that are not closed.  There are no borders to keep fish in a particular area. And, by only preventing fishing, they do not address other important ocean issues such as climate change and ocean acidification.  

Myth: If you close off ocean areas to fishing, it benefits fish populations inside and outside the MPA. 

Fact: A 2023 paper by scientists is the latest research to show this is not the case. In the study, Hampton et al 2023, recently published in Frontiers in Marine Science, they look at the case of Kiribati’s Phoenix Islands Protected Area (PIPA), which in 2015 banned all fishing and became the world’s largest MPA, covering 408,250 square kilometres of ocean in the Southern Pacific Ocean.  

Before PIPA was established, an average of 22,000 metric tonnes (MT) of skipjack and 1900 MT of bigeye tuna were caught in the area. The paper’s authors have exemplary credentials in Pacific tuna and they found that the PIPA MPA did not improve the overall population of tuna, beyond a moderate increase inside and on the outskirts of the closed ocean space and offers further proof that MPAs simply move fishing pressure elsewhere, and often to more sensitive and pressured areas of the ocean.  

Myth: The fishing industry is just opposed to all MPAs. 

Fact: Untrue. The fishing industry globally has a vested interest in protecting the ocean, but they would prefer it was based on science. Small coastal MPAs, if well enforced, are invaluable for protecting specific marine life that may be at threat, such as corals, seagrass, and kelp, which can be damaged by fishing gear. Seagrass and kelp forests are vital in sequestering carbon. 

Myth: MPAs are only effective if they ban all fishing. 

Fact: Marine protection should be targeted at the specific risk using the appropriate tool. Sometimes that will be a prohibition on fishing, but other times the required management will be different to address the risk (e.g. managing sedimentation or forestry slash). There are many types of MPAs and mostly they all have their uses if they are targeted at a specific problem. Some of these MPAs only limit certain fishing methods, not ban fishing completely. For example, Benthic Protection Areas (BPAs) ban fishing within 100 metres of the seafloor. This protects the seafloor but still allows fishers to catch fish in the waters above.  

The New Zealand fishing industry approached the government in 2007 to propose 17 areas of seafloor that could be protected from dredging and bottom trawling through BPAs, and the government instigated them that year. That brought the area of New Zealand’s EEZ protected from bottom trawling up to 32 percent. Before that, only two percent was protected. 

Myth: Banning all fishing is much better for the planet. 

Fact: There are some significant impacts on small coastal nations when all fishing is banned. The marine environment is often the only source of food and income of indigenous peoples, and despite a switch to tourism being promoted as an alternative, this is unproven to be better for revenue generation or the environment. If the problem were fishing, fishing management measures to control how much fish is taken out are a better solution.  

Myth: MPAs are the only way to protect the ocean. 

Fact: Sometimes, MPAs are exactly the right tool, but frequently other measures are better for food production and the planet. For example, robust fisheries management promotes healthy and sustainable fish populations. Encouraging fisheries management systems in parts of the world suffering from fish stock depletion through overfishing must be more of a priority, according to the United Nations. Sustainable fishing is an environmental imperative, but it should not be forgotten that it is also a social and economic one. 

Myth: New Zealand is lagging behind other countries in marine protection. 

Fact: New Zealand is leading the world in marine biodiversity protection with 30 percent of our waters afforded protection in some form. Overall, MPAs cover 7 percent (26.3 million km2) of the world’s ocean with New Zealand contributing around 5 percent (1.2 million km2) of this total. Over 90 percent of New Zealand’s EEZ has never been contacted by bottom trawl and over 30 percent of the EEZ is closed by law to bottom trawling. Where we do need to improve is protecting our coastal areas from land-based effects, and MPAs aren’t the right tools for that.