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Holiday Treats Become Invasive Species and Threatens Biodiversity in the U.S. and China

Oct 07, 2021
  • Karen Mancl

    Professor Emerita of Food, Agricultural & Biological Engineering, The Ohio State University, and Fellow, Woodrow Wilson Center for International Scholars

Operation Mitten Catcher” may sound like a military operation, but rather it is an equally important international law enforcement effort that has prevented the importation of over 15,000 invasive Chinese mitten crabs into the U.S. The U.S. Fish and Wildlife Service inspectors are committed to protecting wild ecosystems and agricultural production by stopping the import of invasive species. While Chinese mitten crabs are considered a delicacy served for the New Year and other holiday events in East Asia, the International Union for Conservation of Nature has the mitten crab on their “100 Worst Invaders” list

Mitten crabs are native to the Pacific coast of China and Korea, but once in North America and Europe, the crabs threaten both humans and the natural environment. They outcompete native crabs for food and space, hurting commercial fishing. The crabs also undermine river levees and create bank erosion. As a carrier of the Oriental lung fluke, mitten crabs can also spread a parasitic disease to people who eat their meat undercooked. In the past, the crabs invaded the San Francisco Bay, the Chesapeake and Delaware Bays, and the St. Lawrence Seaway. The U.S. National Oceanic and Atmospheric Administration now has a Mitten Crab Rapid Response Plan to react when mitten crabs are spotted. 

Within the U.S., the Lacey Act authorizes the U.S. Fish and Wildlife Service to regulate and ban the import and transportation of animals and plants. The Service publishes a list of injurious species and listed the mitten crab in 1989 when they were found in San Francisco Bay. At the state level, governments limit the import, possession, transport, and sale of non-native species through a permit system. Some states already prohibit some species that cause a great risk to human and environmental health. For instance, New York, California, Oregon, and Washington all have state laws prohibiting the importation and possession of mitten crabs. 

Invasive Species in China 

In contrast to the U.S., concern about invasive species is relatively new to China, and there is still little to no regulation. In 2003, China’s Ministry of Agriculture established an Office for the Management of Invasive Alien Species and they began collecting and cataloging information on major invasive species. However, China needs to implement plans, laws, and regulations to prevent damage from non-native species. Currently, non-native aquatic species remain under the jurisdiction of 4 agencies: Ministry of Ecology and Environment, Ministry of Natural Resources, Ministry of Agriculture, and the General Administration of Customs.  

Stricter controls of invasive species are seriously needed as China has extensive problems with ecosystem and agricultural damage. Both the red swamp crayfish and the apple snail were imported from America and are now invasive species in China. Crayfish burrow into the banks of streams and rice paddies, causing leaks and erosion. Invasive crayfish are even damaging the banks of the Three Gorges Dam. Apple snails are voracious eaters, consuming the roots of aquatic plants, so they are a huge threat to taro, lotus, water chestnut and especially rice, causing significant damage to crops and waterways.   

Convention on Biological Diversity 

Along with most countries, China ratified the Convention of Biological Diversity (CBD) in 1992, which requires passing new laws to “conserve biodiversity, use its components in a sustainable way, and share the various benefits of genetic resources fairly.” For nearly twenty years U.S. Senators have refused to ratify the CBD, stating U.S. environmental laws are sufficiently strong. China will host the rescheduled CBD 15th Convention of the Parties in Kunming this month. As host, China assumed the Convention presidency and has the opportunity to show global environmental leadership. 

While China is making progress in protecting terrestrial environments, non-native aquatic species remain a huge biodiversity threat. The estimated damage from China’s 544 invasive species is more than 200 billion RMB each year according to the Center for Management of Invasive Alien Species. Of these, 179 non-native aquatic species have been introduced.

As a sign of China’s serious intent, in Article 18 of the 2020 Biosecurity Law calls for cataloging information on the major invasive species. Encouragingly, in January 2021, China’s Ministry of Agriculture and other key ministries have set a goal to complete the cataloging and shape actions by 2025, and to control the risk of invasive species by 2035, including the apple snail.

Customs officials in both China and the U.S. continue to serve on the front lines and to protect the world from environmental threats, and are constantly on the lookout for invasive species, like the mitten crab. For example, nearly 4000 different species were intercepted by Chinese customs in 2020. In 2017, U.S. customs intercepted 352 pests, and in a large-scale effort, U.S. Customs seized 3400 pounds of invasive Chinese mitten crabs sent in 51 separate shipments from China and Hong Kong into the Cincinnati, Ohio airport in 2019. Each crab would sell in the retail market for 50 USD. With high demand and price, attempts to smuggle in mitten crabs will continue, along with their extensive threat to the environment and biodiversity.

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