A new study finds that seagrass meadows could help feed millions
Underwater seagrass fields could play an important role in combating malnutrition among vulnerable coastal communities, according to new research published in the journal Cell Reports Sustainability.
The study was conducted by scientists from Stockholm University and the Seaweed Project. It found that fish caught in seagrass meadows provide a stronger mix of essential nutrients than fish collected from nearby coral reefs.The research team studied fish populations across 20 seagrass meadows and 20 coral reefs along a 3,000-kilometre stretch of East Africa’s coast, covering the areas between Kenya and Mozambique.
Millions of people living in these tropical regions rely heavily on fishing for food and income, while many communities still face poverty and nutritional challenges.Instead of looking at nutrients separately, the researchers examined the overall nutritional value of fish as a whole food source. They measured six important nutrients essential to human health: calcium, iron, zinc, selenium, vitamin A and omega-3 fatty acids.
The results showed that after adjusting for fish weight, fish communities living in seagrass meadows were on average 1.6 times more nutritionally dense than those around nearby coral reefs.“Fish don’t feed people one nutrient at a time,” said Dr. Benjamin Jones, chief conservation officer at the Seagrass Project, who led the research during his doctoral studies at Stockholm University. “They come as a package.
“One fish contains iron, zinc, calcium, selenium, vitamin A and omega-3. We wanted to understand which habitats produce fish that contain the best combination of these nutrients.”
Seagrass meadows act like a natural supermarket
The difference became even clearer when the researchers looked at the most common fish species caught and eaten by local communities.For the three most important fish species in the region, the nutritional support provided by seagrass meadows was eight times higher than that provided by coral reefs.Species such as rabbitfish and parrotfish, which are important sources of food for coastal residents, were more common in seagrass areas. Rabbitfish were found to be five times more abundant in seagrass meadows than coral reefs, while parrotfish were 65 times more common.“We know that coral reefs contain more fish overall, but seagrass meadows contain more fish that are important to local food,” Jones said.
“This changes the way we have to think about these habitats. Seagrasses are not just a nursery for fish, nor just a carbon storehouse, they are food infrastructure, nature’s own supermarket.”The health benefits can be significant for coastal families. The study found that eating a medium-sized fish caught from a seagrass meadow can provide a young child with about 5% of his daily iron needs, 21% of his zinc needs, and 70% of his selenium needs.
Protect more than just coral reefs
The findings challenge the traditional focus of marine conservation, which often places coral reefs at the center of global conservation efforts. Coral reefs remain critically important and are under serious pressure from overfishing and rising ocean temperatures.However, seagrass meadows are also rapidly disappearing due to coastal construction, industrial waste, damage from human activity, and pollution carried by rivers from farms and cities.The researchers argue that conservation efforts need to consider both ecosystems because they support human communities in different ways.“If we lose seagrass meadows, we don’t just lose their habitat,” Jones warned. “We may be losing a source of nutrition for millions of people who desperately need it.”The study does not suggest replacing coral reef protection with seagrass conservation. Instead, researchers say both environments need support because they play different roles.Coral reefs produce a greater quantity of fish overall, while seagrass meadows provide greater access to some food fish that contain valuable combinations of nutrients.“Coral reefs and seagrass meadows work together,” Jones said. “If we want coastal fisheries to be able to feed people, we have to protect the entire marine landscape.”
Human activity protection of seaweeds
Saving these underwater meadows will require action beyond the ocean itself. Many of the biggest threats to seagrass start on land, researchers say.They recommend stronger investment in wastewater treatment systems, cleaning up rivers, reducing agricultural pollution, and managing fisheries more equitably to protect ecosystems and the people who depend on them.The study also discusses a potential problem associated with the growing interest in blue carbon markets, where companies invest in ecosystems such as seagrass because they store carbon. The researchers warn that conservation projects should not prevent local communities from accessing traditional fishing grounds.The authors stress that protecting seagrasses must include the people who depend on them for food and livelihoods.“Seagrass conservation has to be about people and nature as well,” Jones concluded. “These meadows store carbon, support biodiversity and help feed millions. This makes them one of the most important ecosystems on Earth.”
