Seagrass fish provide vital nutrients for coastal diets

Marine surveys across 40 coastal locations spanning Kenya to Mozambique indicate that seagrass meadows supply fish with higher nutritional value than neighboring coral reefs. While coral systems shelter greater overall numbers and diversity of marine wildlife, the fish gathered from underwater grass beds provide a richer blend of essential dietary elements, according to a paper in the journal Cell Reports Sustainability.

The investigation evaluated six critical nutrients, including vitamin A, calcium, zinc, iron, omega-3 fatty acids, and selenium. After adjusting for depth and animal biomass, scientists determined that seagrass habitats were 1.6 times more nutritionally diverse than reefs. A typical fish taken from these meadows can supply roughly seventy percent of daily selenium requirements, along with significant portions of necessary zinc and iron.

Nutritional differences were even more pronounced among staple food varieties. For target species like rabbitfish and parrotfish, the availability of micronutrients was over eightfold greater in meadow environments. Study lead author Benjamin Jones explained that marine management often focuses strictly on harvest volume, yet dependable access to nourishing catches is equally critical for vulnerable coastal families.

Outside experts noted that habitat conditions and fish maturity might influence the comparison. Marine ecologist Tim McClanahan observed that researchers examined shallow waters containing mostly juvenile four-inch fish, suggesting that broader sampling across depths could narrow the gap. Scientists also pointed out that the study omitted edible invertebrates such as crabs and octopuses, and did not examine whether catches directly reduce human malnutrition.

Beyond feeding nearby communities, seagrass meadows protect shorelines from storms and capture substantial amounts of carbon. However, agricultural runoff, sewage discharge, coastal construction, and unregulated netting continue to degrade these underwater fields. Researchers emphasized that marine protection strategies must recognize the vital connection between healthy seagrass ecosystems and regional nutritional security.