When communities along the coast of Kenya and Mozambique pull fish from the sea, many assume the most nutritious catch comes from colorful coral reefs. A new study reveals a surprising truth: fish from humble seagrass meadows may actually be better for you.
Researchers at Project Seagrass and Stockholm University studied fish from 40 locations along a 3,000-kilometer stretch of coastline between Kenya and Mozambique. They examined 20 seagrass meadows and 20 coral reefs, looking at six nutrients that people need to stay healthy: calcium, iron, zinc, selenium, vitamin A, and omega-3 fatty acids.
The results, published in the journal Cell Reports Sustainability, show that fish from seagrass meadows were 1.6 times more nutritionally rich than fish from coral reefs. The difference was even more striking when looking at the fish species that local fishers actually catch and eat. For the three most important food fish species in the region, nutrient support was more than eight times higher in seagrass meadows.
"Fish don't nourish people one nutrient at a time," said Dr. Benjamin Jones, who led the research as a PhD student at Stockholm University and now serves as chief conservation officer at Project Seagrass. "They come as a package. A single fish contains iron, zinc, calcium, selenium, vitamin A and omega-3s. We wanted to understand which habitats produce fish with the best mix of these nutrients."
Two fish especially prized by coastal communities thrive in seagrass. Rabbitfish were five times more abundant in seagrass meadows than on coral reefs, while parrotfish were a remarkable 65 times more common. A single average fish from seagrass could provide about 5 percent of a young child's daily iron needs, 70 percent of their selenium needs, and 21 percent of their zinc needs.
The findings challenge how people think about ocean conservation. Coral reefs grab headlines and funding because they are home to dazzling marine life. But the research shows seagrass meadows, though less flashy, play a crucial role in feeding coastal communities. Millions of people in tropical coastal regions rely on fish for food and income, and many of these areas struggle with poverty and malnutrition.
"We know that coral reefs have more fish overall, but seagrass meadows had more of the fish that really matter for local food," said Jones. "This changes how we should think about these habitats. Seagrass isn't just a fish nursery, nor just a carbon stock, it's food infrastructure, nature's own supermarket."
Both habitats face serious threats. Coral reefs suffer from climate change, warming waters, and overfishing. Seagrass meadows are disappearing too, damaged by pollution, coastal construction, and dirty water running off from land. Yet seagrass gets far less attention and protection.
The researchers argue that saving seagrass for food security means more than drawing boundaries in the ocean. Better sewage treatment and cleaner rivers flowing into the sea would help these underwater meadows survive. "If we lose seagrass meadows, we are not just losing habitat," said Jones. "We may be losing a source of nutrition for millions of people who need it most."