Sushi Parasite Has Increased 283x in Nearly 40 Years
The population of a marine parasite that sometimes worms its way into sushi has increased by 283 times in the last nearly 40 years, a University of Washington (UW)-led study has found.
The study, published in Global Change Biology Thursday, reviewed the literature and found a significant rise in the abundance of the parasite Anisakis, or "herring worm." This isn't especially concerning for humans, who experience the worm as a nasty bout of food poisoning that then resolves, but it could have serious consequences for marine mammals, who play host to the parasites for years.
"One of the important implications of this study is that now we know there is this massive, rising health risk to marine mammals," study coauthor and UW School of Aquatic and Fishery Sciences assistant professor Chelsea Wood said in the UW press release. "It's not often considered that parasites might be the reason that some marine mammal populations are failing to bounce back. I hope this study encourages people to look at intestinal parasites as a potential cap on the population growth of endangered and threatened marine mammals."
The next time you eat sashimi, nigiri or other forms of raw fish, consider doing a quick check for worms. 🍣😳 https://t.co/juL5dW2NDu— UW SAFS (@UW SAFS)1584649387.0
The researchers looked at a total of 123 papers published between 1967 and 2017 to assess how the abundance of two marine parasites had changed over time: Anisakis and another parasite known as Pseudoterranova, or "cod worm." Anisakis abundance rose 283-fold from 1978 to 2015, while Pseudoterranova abundance did not change. This means that Anisakis has risen from less than one for every 100 hosts caught to more than one in every host caught, ScienceAlert explained.
Ironically, while Anisakis might threaten the health of marine mammals, its rise may have been triggered by their success.
"My gut is that this is about the improvements we've made in marine mammal conservation," Wood told ScienceAlert. "The time frame of our study directly overlaps with when a bunch of really important marine mammal legislation went into effect like the Marine Mammal Protection Act in 1972 and the international whaling commission moratorium on commercial whaling which came in the 1980s."
The one wrinkle in this theory is which mammals usually play host to the worm. Anisakis hatches in the ocean and first infects small animals like shrimp, the UW explained. They then make their way up the food web as the shrimp are eaten by fish, who are eaten by bigger fish, until they end up in the intestines of Cetaceans like whales or dolphins. Here they can live and reproduce for years, reentering the ocean in the animals' feces to start the cycle again.
While Anisakis abundance has risen, Pseudoterranova, which typically infects fish, sea lions and seals, has not. However, seals and sea lions have done much better than whales, Wood told ScienceAlert, which means one would expect Pseudoterranova abundance to have increased instead. However, she speculated it was possible the parasite was actually increasing because it had fewer hosts to pass through.
Other factors that could have caused the rise include the climate crisis and increased runoff from fertilizers, according to the press release.
So what happens if humans happen to ingest one of the worms? Nausea and vomiting that is unpleasant, but temporary.
"When they enter the intestine of a human, it's a great disappointment to the worm. They're not going to be able to complete their life cycle there," Wood told New Scientist.
Wood said that sushi lovers shouldn't worry, as chefs were expert de-wormers.
"I still eat sushi all the time," she told New Scientist.
However, if you are concerned, just cut your nigiri in half and look for worms yourself, she advised in the press release.
EcoWatch Daily Newsletter
New York State Attorney General Letitia James announced Thursday that she will attempt to dismantle the National Rifle Association (NRA), arguing that years of corruption and mismanagement warrant the dissolution of the activist organization, as CNN reported.
<div id="7eb49" class="rm-shortcode" data-rm-shortcode-id="83819841e380a7072ec66d3186c160e8"><blockquote class="twitter-tweet twitter-custom-tweet" data-twitter-tweet-id="1291705003984510977" data-partner="rebelmouse"><div style="margin:1em 0">🚨RESPONSE to #Mauritius #OILSpill 🚨 “Once again we see the risks in oil: aggravating the #ClimateCrisis, as well as… https://t.co/PBLioZat6X</div> — Greenpeace Africa (@Greenpeace Africa)<a href="https://twitter.com/Greenpeaceafric/statuses/1291705003984510977">1596801446.0</a></blockquote></div><p>"There is no guaranteed safe way to extract, transport and store fossil fuel products. This oil leak is not a twist of fate, but the choice of our twisted addiction to fossil fuels. We must react by accelerating our withdrawal from fossil fuels," Greenpeace Africa Senior Climate and Energy Campaign Manager Happy Khambule said in a <a href="https://www.greenpeace.org/africa/en/press/11864/greenpeace-africa-response-to-mauritius-oil-spill/?utm_campaign=oil&utm_source=t.co&utm_medium=post&utm_content=single-image&utm_term=mauritius-oil-spill-reactive" target="_blank">statement Friday</a>. "Once again we see the risks in oil: aggravating the <a href="https://www.ecowatch.com/tag/climate-crisis" target="_self">climate crisis</a>, as well as devastating oceans and <a href="https://www.ecowatch.com/tag/biodiversity" target="_self">biodiversity</a> and threatening local livelihoods around some of Africa's most precious lagoons."</p>
- Which Country Will Be First to Go Completely Underwater Due to ... ›
- Overfishing Starts Here - EcoWatch ›
By Gianna-Carina Grün
While the first countries are easing their lockdowns, others are reporting more and more new cases every day. Data for the global picture shows the pandemic is far from over. DW has the latest statistics.
What's the Current Global Trend?<p>The goal for all countries is to make it to the blue part of the chart and stay there. Countries and territories in this section reported zero new cases both this week (past seven days) and the week before.</p><p>Currently, that is the case for 14 out of 209 countries and territories. </p>
How Has the Covid-19 Trend Evolved Over the Past Weeks?<p>The situation has improved slightly: 87 countries report more cases this week than last week. </p>
- Coronavirus Has Infected More Than 60,000 Worldwide, New ... ›
- Apple Fire Forces 7,800 to Seek Shelter in Coronavirus-Ravaged ... ›
- CDC Expands List of Those With Higher COVID-19 Risks - EcoWatch ›
- The South Isn't Prepared for a COVID-19 Surge - EcoWatch ›
- Until Teachers Feel Safe, Widespread In-Person K-12 Schooling ... ›
- Teens and Tweens Are Fastest COVID-19 Spreaders, New Study ... ›
- How Other Countries Reopened Schools During the Pandemic ... ›
- Young Children May Have Higher Coronavirus Levels, Raising ... ›
- COVID-19: What Experts Think About Reopening Schools - EcoWatch ›
Hurricane forecasters predict the 2020 hurricane season will be the second-most active in nearly four decades.
Three years ago, scientists predicted it would happen. Now, new NASA satellite imagery confirms it's true: two ice caps in Canada's Nunavut province have disappeared completely, providing more visual evidence of the rapid warming happening near the poles, as CTV News in Canada reported.
- Climate Explained: What the World Was Like the Last Time Carbon ... ›
- Polar Bears Could Be Nearly Gone by 2100, Study Finds - EcoWatch ›
- Greenland's Ice Sheet Is Melting at Rate That Surpasses Scientists ... ›
By Katell Ané
The European Commission launched a new Farm to Fork strategy in an effort to reduce the social and environmental impact of the European food system. It is the newest strategy under the European Green Deal, setting sustainability targets for farmers, consumers, and policymakers.