Coral reef ecosystems support diverse small-scale fisheries – and the fish they catch are rich in micronutrients vital to the health of millions of people in the tropics, a new Lancaster University-led study reveals

Peer-Reviewed Publication

LANCASTER UNIVERSITY

Researchers studying coral reefs damaged by rising sea temperatures have discovered an unexpected ‘bright spot’ of hope for communities who depend upon them for food security.

Coral reef ecosystems support diverse small-scale fisheries – and the fish they catch are rich in micronutrients vital to the health of millions of people in the tropics, a new Lancaster University-led study reveals.

And, counter-intuitively, following bleaching events that kill off coral and can transform the composition of reef ecosystems, reef fisheries can remain rich sources of micronutrients, even increasing in nutritional value for some minerals.

The findings, published today in the journal One Earth, show that the availability of micronutrients from coral reef small-scale fisheries may be more resilient to climate change than previously thought. This increased understanding is critical as continued global warming means coral bleaching events are becoming more frequent and more severe, placing greater stress on these vulnerable ecosystems.

Dr James Robinson, who led the study, said: “Our findings underline the continuing importance of these fisheries for vulnerable coastal communities, and the need to protect against over-fishing to ensure long-term sustainability of reef fisheries.”

The researchers also caution that while these fisheries have proved more resilient to climate change disturbance than expected, continued understanding of the long-term impacts of climate change to coral reef fisheries, and more data from other regions, are urgent priorities.

More than six million people work in small-scale fisheries that rely on tropical coral reefs. Their catches help to feed hundreds of millions of coastal people in regions with high prevalence of malnourishment, causing stunting, wasting and anaemia. However, until now, the nutritional composition of coral reef fish catches, and how climate change might affect the nutrients available from reef fisheries, was not known.

This study, led by scientists from Lancaster University and involving an international team of researchers from the Seychelles, Australia, Canada and Mozambique, benefitted from more than 20 years of long-term monitoring data from the Seychelles, where tropical reefs were damaged by a large coral bleaching event in 1998, killing an estimated 90% of the corals.

Following the mass-bleaching event, around 60% of the coral reefs recovered to a coral-dominated system, but around 40% were transformed to reefs dominated by seaweeds. These differences provided a natural experiment for the scientists to compare the micronutrients available from fisheries on reefs with different climate-driven ecosystem compositions.

The scientists, who used a combination of experimental fishing, nutrient analysis, and visual surveys of fish communities in the Seychelles, calculated that reef fish are important sources of selenium and zinc, and contain levels of calcium, iron and omega-3 fatty acids comparable to other animal-based foods, such as chicken and pork.

They also found that iron and zinc are more concentrated in fish caught on reefs that have been transformed after coral bleaching and are now dominated by macroalgae such as Sargassum seaweeds. These seaweeds have high levels of minerals, which, researchers believe, is a key reason why the algal-feeding herbivorous fishes found in greater numbers on transformed reefs contain higher levels of iron and zinc.

Dr Robinson said: “Coral reef fish contain high levels of essential dietary nutrients such as iron and zinc, so contribute to healthy diets in places with high fish consumption. We found that some micronutrient-rich reef species become more abundant after coral bleaching, enabling fisheries to supply nutritious food despite climate change impacts. Protecting catches from these local food systems should be a food security priority.”

The researchers believe the results underline the need for effective local management to protect the sustainability of reef fisheries, as well as policies that retain more of reef fish catches for local people and promote traditional fish-based diets. These can help reef fisheries to best contribute to healthy diets across the tropics.

Professor Christina Hicks, a co-author on the study, said: “Fish are now recognised as critical to alleviating malnutrition, particularly in the tropics where diets can lack up to 50% of the micronutrients needed for healthy growth. This work is promising because it suggests reef fisheries will continue to play a crucial role, even in the face of climate change, and highlights the vital importance of investing in sustainable fisheries management.”

The findings are outlined in the paper ‘Climate-induced increases in micronutrient availability for coral reef fisheries’.

The study’s authors include: James Robinson, Eva Maire, Nick Graham and Christina Hicks from Lancaster University; Nathalie Bodin from Seychelles Fishing Authority and Sustainable Ocean Seychelles; Tessa Hempson from James Cook University and Oceans Without Borders; Shaun Wilson from the Department of Biodiversity, Conservation and Attractions in Australia, and Oceans Institute, Australia; and Aaron MacNeil from Dalhousie University.

DOI: 10.1016/j.oneear.2021.12.005              

JOURNAL

One Earth

DOI

10.1016/j.oneear.2021.12.005 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Animal tissue samples

ARTICLE TITLE

Climate-induced increases in micronutrient availability for coral reef fisheries

ARTICLE PUBLICATION DATE

6-Jan-2022

From EurekAlert!

From ClimateREALISM

By James Taylor -January 8, 2022

The New York Times published an article yesterday attempting to frighten skiers into becoming climate activists by claiming snow cover is diminishing throughout the country. “Skiing is an endangered sport,” claims the Times. In reality, objective data show that snow cover has been increasing during the past 30 years and current snowfall in the nation’s best ski country is setting new records this ski season. “All the news that’s fit to print” appears a lot more like “all the propaganda that’s fit to print.”

The Times’ article asserts, “Skiing is an endangered sport, caught between a warming planet and a global pandemic.” Moreover, according to the article, “In recent years, with snow cover diminishing and untouched powder increasingly difficult to reach, skiers like Ms. Backstrom have been pushed onto groomed trails more often.”

Utilizing satellite measurements, the Rutgers University Global Snow Lab (GSL) keeps precise data on global, hemispheric, and continental snow cover dating back to the 1960s. According to the GSL data, the past 30 years have seen no decline in global or North American snow cover. Instead, there has been a modest increase in snow cover during the past three decades.

Even compared to the 1960s, which fell in the middle of the 1945-to-1977 global cooling period, recent North American snow cover is only marginally less than what was the case during that cold era 60 years ago. That small decline is due entirely to snow cover retreating somewhat earlier in the spring. Even so, Northern Hemisphere snow extent has enjoyed long-term growth during the past 60 years during the fall and winter seasons.

The Times’ article is particularly ironic considering the many snowfall records that have been set in prime ski regions during the past year. North Lake Tahoe, which is home to several of the best ski slopes in the country, enjoyed a record 18 feet of snow last month. Yosemite National Park set a snowfall record, also, last month. Even further south, Mammoth, California set snowfall records as recently as May, 2019.

Sorry, New York Times, skiing is not endangered and objective scientific data show powdered ski slopes are increasingly easy to reach.

James Taylor is the President of the Heartland Institute. Taylor is also director of Heartland’s Arthur B. Robinson Center for Climate and Environmental Policy. Taylor is the former managing editor (2001-2014) of Environment & Climate News, a national monthly publication devoted to sound science and free-market environmentalism.