Marine protected areas can benefit people and planet

A study in the journal One Earth examines the links between marine biodiversity conservation, human health and wellbeing. Its findings indicate that marine protected areas can deliver benefits for people as well as the planet.

Governments legally designate these parts of the ocean as important for conserving marine life. Protection is provided by restricting human activities within the area and nearby.

After a government establishes a marine protected area, people generally cannot live there, fish, construct a beach resort, establish a fish farm or drill for oil. Regulations differ between locations, but their shared purpose is to enable nature to thrive by reducing human pressure as far as possible.

As ocean protection is set to grow under the UN-backed biodiversity plan’s "30×30" target, which seeks to safeguard 30% of the world’s land and oceans by 2030, understanding the consequences for people as well as wildlife is essential.

The research was carried out by the conservation charity World Wide Fund for Nature, the Harvard Institute of Public Health and Duke University’s marine laboratory. Led by marine conservation scientist Daniel Viana, the researchers assessed every scientific paper published since 1973 on marine protected areas and their effects on people.

Among 234 closely monitored marine protected areas worldwide, they found that more than 60% recorded improvements in both environmental conservation and human wellbeing.

Marine protected areas and sustainable fishing

The research covered marine protected areas that permit "sustainable use" through controlled, selective fishing. Such approaches include hook-and-line fishing and fish traps, methods that do not physically harm sensitive habitats including coral reefs.

The paper indicates that investment in marine protected areas generally brings direct gains for the health and livelihoods of nearby communities. These advantages usually arise from larger harvests of fish and other aquatic foods, including shellfish and seaweeds. Fisherfolk can earn more, while communities have better access to nutrient-rich food from aquatic sources.

The largest benefits for livelihoods based on fishing occur in small island states with extensive marine protected areas, including Bonnaire, Palau and the Cook Islands. In these places, area-based conservation measures are linked to more than 95% of fish catches.

Although substantial evidence showed that marine protection improved access to aquatic food, the researchers identified remarkably few studies that measured its effects on human nutrition directly.

Of the 237 studies assessed, just three examined how the establishment of marine protected areas changed the diets of people living nearby. Only one, conducted in the Philippines, connected dietary changes to health outcomes: improved access to fish in diets resulting from marine conservation was associated with fewer stunted children in surrounding communities.

Are there more nutrients in the sea?

The seas, lakes, rivers and floodplains around our continents and islands contain edible plants and animals that are rich in vitamins, minerals and fatty acids.

Micronutrients in aquatic foods are highly bioavailable, meaning they are readily absorbed by the body. If these foods are harvested sustainably and supplied to people who are nutritionally vulnerable, they could help prevent malnutrition among millions of people living along coasts.

The new report calculated the micronutrient contribution to human diets made by aquatic foods that prosper after marine protected areas are established. It brings together information on the nutrient content of all aquatic foods harvested within and around marine protected areas, alongside fish-catch data from neighbouring waters.

Existing networks of marine protected areas support 14% of the global supply of six essential micronutrients derived from marine fisheries. This is accomplished while protecting only 8% of the world’s oceans. As marine organisms are allowed to grow in abundance inside protected zones, fish populations in surrounding waters are replenished. Protecting marine wildlife therefore helps maintain stocks of fish and shellfish.

This can produce larger catches, higher earnings from fishing or tourism, and a greater supply of food. More nutrients can lead to improved health. The pattern applies to both marine protected areas containing a strict no-take zone, where all fishing is prohibited, and areas that permit regulated fishing.

Aquatic food, nutrition and growing demand

As the population grows, so does demand for aquatic food. Wild catches are supplemented by aquaculture and mariculture, the freshwater and marine counterparts of raising crops and livestock on land. More than half of the aquatic foods eaten directly by people now come from aquaculture, much of which takes place in inland waters rather than at sea.

Yet collecting wild food from marine ecosystems remains vital in many countries, particularly developing island and coastal nations. It helps feed the more than 3 billion people who obtain over 15% of their animal-source protein from aquatic foods.

Despite their capacity to tackle global micronutrient deficiencies, aquatic foods have until recently received too little attention in policies and programmes aimed at ending hunger and malnutrition.

However, information is now available on the nutritional composition of the world’s fish species. Research such as this can support an approach known as "nutrition-sensitive fisheries and aquaculture": rather than managing fisheries to maximise catches or profits, they could be managed to maximise their contribution to human nutrition.

Connecting ocean conservation with human health is a promising concept, but research gaps remain. It is uncertain who gains when tourism and fishing revenues rise, or whether larger catches reach the people who need them most. In the Maldives, for instance, tourists rather than local residents consume more than 80% of reef fish.

Using marine protected areas to address malnutrition will be difficult. Many of these areas lack effective management. In comparison, 77% of catches from the world’s fisheries are drawn from sustainably managed stocks, although those stocks offer limited scope for expansion as demand increases. Aquaculture could provide that expansion, but the industry is still progressing towards sustainability.

Many major pressures on marine ecosystems and wild fisheries, including climate change and pollution, cannot be adequately addressed through local marine-habitat protection alone. Even so, the study shows that relationships between nature and people can be regenerative rather than exploitative.

Edward H. Allison, Honorary Visiting Professor, Reef Environments (REEFS Group), Lancaster University

This article is republished from The Conversation under a Creative Commons license. Read the original article.