Unexpected hope for millions as bleached coral reefs continue to provide nutritious seafood – Did you know?
A new study led by Lancaster University shows that coral reef ecosystems support a diversity of small-scale fisheries – and the fish they catch are rich in micronutrients essential to the health of millions of people. in the tropics.
LANCASTER UNIVERSITY
Researchers studying coral reefs damaged by rising sea temperatures have discovered an unexpected ‘bright spot’ of hope for communities that depend on them for food security.
A new study led by Lancaster University reveals: Coral reef ecosystems support a diversity of small-scale fisheries – and the fish they catch are rich in micronutrients important to the health of their customers. million people in the tropics.
And, intuitively, after bleaching events that kill corals and can alter the composition of reef ecosystems, reef fisheries can remain a rich source of micronutrients, even increasing their nutritional value. nutrients for some minerals.
The findings, published today in the journal One Earth, suggests that the availability of micronutrients from small-scale reef fisheries may be more resilient to climate change than previously thought. It is important to advance this understanding as continued global warming means coral bleaching events are becoming more frequent and more severe, placing greater stress on ecosystems. this vulnerability.
Dr James Robinson, who led the study, said: “Our findings highlight the continued importance of these fisheries for vulnerable coastal communities and the need to preserve them. protection against overfishing to ensure the long-term sustainability of reef fisheries.”
The researchers also warn that although these fisheries have proven more resilient to the disturbances of climate change than expected, there is continuing to be a better understanding of the long-term impacts of climate change. Climate change for reef fisheries, and more data from other regions, are pressing priorities.
More than six million people are small-scale fishermen who rely on tropical coral reefs. Their catches help feed hundreds of millions of coastal people in areas with high rates of malnutrition, which causes stunting, emaciation and anemia. However, until now, the nutritional composition of reef fish stocks, and how climate change might affect the nutrients available from reef fisheries were unknown.
This study, led by scientists from Lancaster University and involving an international team of researchers from the Seychelles, Australia, Canada and Mozambique, benefited from more than 20 years of long-term follow-up data term from the Seychelles, where tropical reefs were destroyed by a massive coral bleaching event in 1998, which killed about 90% of the coral population.
After the mass bleaching event, about 60% of coral reefs recovered back to the dominant coral system, but about 40% were transformed into algae-dominated reefs. These differences provided a natural experiment for scientists to compare micronutrients available from fisheries on coral reefs with different climate-driven ecosystem compositions.
The scientists, who used a combination of experimental catch, nutrient analysis and visual surveys of fish communities in the Seychelles, calculated that reef fish are an important source of selenium and zinc, copper and copper. Contains comparable levels of calcium, iron and omega-3 fatty acids. to other foods of animal origin, such as chicken and pork.
They also found that iron and zinc are more concentrated in reef fish that have been modified after coral bleaching and are now dominated by macroalgae such as the seaweed Sargassum. The researchers believe that this seaweed has a high mineral content, which is the main reason herbivorous fishes that feed on algae found in greater numbers on modified reefs that contain high levels. higher iron and zinc.
“Coral reef fish contain high levels of essential dietary nutrients such as iron and zinc, so contribute to a healthy diet where fish intake is common,” said Dr. high. We found that some micronutrient-rich reef species became more abundant after coral bleaching, enabling fisheries to provide nutritious food despite the effects of climate change. Protecting the catch from these local food systems should be a food security priority.”
The researchers believe that the results highlight the need for effective local management to protect the sustainability of reef fisheries, as well as policies that retain more of the reef fish catch for people. local and promote traditional fish-based diets. These can help reef fisheries best contribute to healthy diets throughout the tropics.
Professor Christina Hicks, co-author of the study, said: “Fish is now recognized as crucial to reducing malnutrition, particularly in tropical regions, where diets can be up to 50% deficient. essential micronutrients for healthy growth. This work is promising as it shows that reef fisheries will continue to play an important role, even in the face of climate change, and highlights the vital importance of investing in fisheries management. sustainable fish. ”
The findings are outlined in the paper ‘Climate-induced increase in micronutrients for reef fisheries’.
The study’s authors include: James Robinson, Eva Maire, Nick Graham and Christina Hicks from Lancaster University; Nathalie Bodin from Seychelles Fisheries and Sustainable Oceans Seychelles; Tessa Hempson from James Cook University and Oceans Without Borders; Shaun Wilson from the Department of Biodiversity, Conservation and Landscape in Australia, and the Ocean Institute, Australia; and Aaron MacNeil from Dalhousie University.
DOI: 10.1016 / j.oneear.2021.12.005
JOURNEYS
One Earth
DOI
10.1016 / j.oneear.2021.12.005
RESEARCH METHODS
Experimental study
RESEARCH SUBJECTS
Animal tissue samples
ARTICLE TITLE
Climate-induced increase in micronutrient supply for reef fisheries
ARTICLE PUBLICATION DATE
January 6, 2022
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