Northeast Marine Introduced Species (NEMIS) - Print Edition

Pathways and Prevention : Live Seafood Releases

What is the Problem?

A street vendor in Dalian China selling live seafood and algae is similar to those found in Asian live seafood markets in New York City and Boston.
Photo: J Pederson, MIT

In Korea, sea squirts are grown for food and sold in the fresh seafood markets throughout the city. The sea squirts are used in a Korean dish [ Recipe ].
Photo: J Pederson, MIT

Slider turtles are used to make turtle soup. This species, Trachemys scripta elegans is the red-eared slider and has been introduced throughout the U.S. It is locally established in Connecticut, Massachusetts, and New York and collected in Maine.
Photo: Greg Hume

The grass carp or white amur (Ctenopharyngodon idella) is used to graze plants that grow in waters with other aquaculture carp species. Because it is considered invasive, it is prohibited from being sold in most New England states including Massachusetts, Maine, Connecticut, and New Hampshire.
Photo: J Mathieu, UC Berkeley

One pathway that introduces invaders into the environment, but has not received significant attention, is the live and fresh seafood industry. The live and fresh seafood vector involves both consumers and commercial vendors. Imported seafood enters the U.S. through 18 ports throughout the U.S., six of which are in the East Coast.

Seafood refers to both freshwater and marine fish, invertebrates, and algae. Thus, live seafood is primarily fish, shellfish, and other organisms in tanks or water, bivalves on ice, and live algae, which if discarded into bodies of water may result in an introduction of that species (Weigle et al. 2005).

We conducted a survey of species available in the live seafood markets in Boston and New York City, excluding species on ice in seafood stores and lobsters kept in tanks (supermarkets and seafood stores). Our limited survey indicated over 20 known non-native species, many of which have the potential to survive in the region if released.

What are we concerned about?

Released non-native seafood may become invasive in its new ecosystem, altering community structure and species composition, facilitating the introduction of hitchhikers, and spreading disease and parasites. Two examples of recently released food fish are the snakehead fish (Channa sp.) and the Chinese mitten crab (Eriocheir sinensis) (USDA APHIS 2006; USFWS 2002). The snakehead fish is a voracious predator that feeds on native fish populations. The Chinese mitten crab has the potential to destabilize levies and river banks, adding to flooding threats.

Of particular concern are the discard of live or fresh seafood, such as oysters, mussels, and clams and other fish and shellfish from seafood markets along the coast. These species may have hitchhikers such as algae, small animals, larvae, and juvenile species associated with shells and carapaces as well as carry diseases that may infect new areas.

What are the solutions?

One way to minimize the introduction of introduced species via the live seafood trade is to create outreach materials that raise public awareness on proper seafood handling and disposal and provide commercial dealers with information about the risks of introductions. However, many live seafood species are frequently purchased by populations who do not speak English fluently.

To reach live seafood consumers who are not fluent in English, we have developed outreach brochures in a number of relevant languages, including Chinese, Khmer, Viet Namese, and Korean to reach the majority of Asian populations that purchase live seafood in the Northeast as well as English and Spanish. These are available at

If you purchase fresh or live seafood from seafood markets and supermarkets, do not discard anything into the waters. Of particular concern are oysters (they carry live organisms even after they have been sitting on ice for several days), bivalves that may carry parasites and diseases, crustaceans that are non-native (e.g. Dungeness crabs collected from Massachusetts Bay), and any live fish species.


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