shellfish

Mollusks And Microplastics | Earth Wise

January 26, 2021 By EarthWise Leave a Comment

Plastic debris comes in all different shapes and sizes, but pieces that are less than five millimeters in length are called microplastics. Microplastics are everywhere, including in the food we eat, the water we drink, and the air we breathe.

Much of the oceanic microplastic pollution comes from the breakdown of plastic litter. Another source of microplastic pollution is microbeads. Microbeads, which are sometimes added to cleansing and exfoliating personal care products, pollute the environment when they get flushed down the drain.

According to a new study by researchers at Hull York Medical School and the University of Hull in the U.K., mussels, oysters and scallops have the highest levels of microplastic contamination among seafood. The research team examined 50 studies between 2014 and 2020 to determine the levels of microplastic contamination globally in fish and shellfish. The team found that microplastic content was 0-10.5 microplastics per gram in mollusks, 0.1-8.6 microplastics per gram in crustaceans, and 0-2.9 microplastics per gram in fish.

The researchers found that mollusks collected off the coasts of Asia were the most heavily contaminated with microplastics. China, Australia, Canada, Japan and the United States are among the largest consumers of mollusks, followed by Europe and the U.K.

While the human health implications of consuming microplastics are not well understood, early evidence from other studies suggest they do cause harm.

According to the research team, more data is needed from different parts of the world in order to better understand how microplastics vary between different oceans, seas, and waterways.

**********

Web Links

Highest levels of microplastics found in molluscs, new study says

Photo, posted September 3, 2007, courtesy of Andrew Malone via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Restoring Seagrass In Virginia | Earth Wise

December 10, 2020 By EarthWise Leave a Comment

Seagrass is found in shallow waters in many parts of the world. They are plants with roots, stems, and leaves, and produce flowers and seeds. They can form dense underwater meadows that constitute some of the most productive ecosystems in the world. Seagrasses provide shelter and food to a diverse community of animals including tiny invertebrates, fish, crabs, turtles, marine mammals and birds.

In the late 1920s, a pathogen began killing seagrasses off the coast of Virginia. In 1933, a hurricane finished them off completely. For nearly 70 years thereafter, the bay bottoms of the Virginia coast were muddy and barren, essentially devoid of fish, shellfish, mollusks and other creatures that inhabit seagrass meadows. The local scallop industry was no more.

The largest seagrass restoration project ever attempted has changed all that. During the past 21 years, scientists and volunteers have spread more than 70 million eelgrass seeds within four previously barren seaside lagoons. This has spurred a natural propagation of meadows that have so for grown to almost 9,000 acres, the largest eelgrass habitat between North Carolina and Long Island Sound.

The long-term research conducted by the team from the University of Virginia shows that the success of the seagrass restoration project is improving water quality, substantially increasing the abundance of fish and shellfish in the bays, and capturing carbon from the water and atmosphere and storing it in the extensive root systems of the grasses and in the sediment below.

The study shows that marine restorations are possible on scales that contribute directly to human well-being.

**********

Web Links

Some Good News: Seagrass Restored to Eastern Shore Bays is Flourishing

Photo, posted May 17, 2019, courtesy of Virginia Sea Grant via Flickr. Photo credit: Aileen Devlin | Virginia Sea Grant.

Earth Wise is a production of WAMC Northeast Public Radio.

We’re Still Eating The Wrong Things

August 23, 2019 By EarthWise 1 Comment

A new study published in the Journal of the Academy of Nutrition and Dietetics has found that despite efforts to increase public awareness of health issues related to diet, the amount of processed meat consumed by Americans has remained unchanged in the past 18 years. Furthermore, our intake of fish and shellfish has not increased. One quarter of US adults are still eating more unprocessed read meat than the recommended level, and less than 15% meet the current guidelines for fish and shellfish consumption.

About the only positive note is that Americans are eating less beef and more chicken than they did 18 years ago and, in fact, for the first time, the consumption of poultry exceeds that of unprocessed red meat.

Accumulating evidence has linked excessive consumption of processed meat to increased risk of obesity, diabetes, cardiovascular diseases, and some cancers. The study’s authors speculate that public awareness of these linkages is not widespread enough to affect change and, in any case, factors other than health – social, cultural, and economic – have greater influence over Americans’ food choices. The top five consumed processed meats are luncheon meat, sausage, hot dogs, ham, and bacon.

The low consumption of fish and shellfish among U.S. adults could be due to high retail prices, lack of awareness of the health benefits, and concerns about mercury contamination in certain types of fish.

Future research is needed to identify barriers to reducing processed meat consumption and increased seafood consumption. Policies such as nutrition quality standards, excise taxes, health warning labels, and other interventions need to be explored.

**********

Web Links

Americans still eat too much processed meat and too little fish

Photo, posted January 28, 2014, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Climate Change And Global Fisheries

April 12, 2019 By EarthWise Leave a Comment

A Rutgers University-led study published in the journal Science has shown that climate change has taken a toll on many of the world’s fisheries and that over fishing has magnified the problem.

Seafood has become an increasingly important source of nourishment as the global population grows, especially in coastal, developing countries where it provides as much as half of the animal protein eaten. More than 50 million people worldwide work in the fisheries industry or subsist on fisheries.

Scientists at Rutgers and the National Oceanic and Atmospheric Administration studied the impact of ocean warming on 235 populations of 124 species in 38 ecological regions around the world. Species included fish, crustaceans such as shrimp, and mollusks such as scallops. They combined data on fisheries with ocean temperature maps to estimate temperature-driven changes in the sustainable catch over 8 decades. The data covered about one-third of the global catch.

According to the study, ocean warming has led to an estimated 4.1% drop in sustainable catches, on average around the world, for many species of fish and shellfish from 1930 to 2010. In five regions that include the East China Sea and the North Sea, the estimated decline was 15 to 35%.

The researchers recommend that fisheries managers eliminate over fishing, rebuild fisheries, and account for climate change in fisheries management decisions. Over fishing provides a one-two punch to fisheries facing warming waters. It not only makes fisheries more vulnerable to ocean warming but continued warming will also hinder efforts to rebuild over fished populations.

**********