U.S. Fish & Wildlife Service August 2013 American Eel in North Carolina

Anguilla rostrata Class: Actinopterygii Order: Anguilliformes Family: Anguillidae Status: Under review View photos on Flickr: http://www.flickr.com/photos/ usfwsnortheast/sets/72157627551792381

Description The American eel is one of 15 fish species of the genus Anguilla, whose members spawn in ocean waters, migrate to coastal American Eel, by Ellen Edmonson and Hugh Chrisp and inland continental waters to grow, via Wikimedia Commons and then return to ocean spawning areas to reproduce - a life history strategy Diet Juveniles arrival to the coast and known as catadromy. The American eel is a nocturnal species, migrate to mature in rivers or estuaries swimming and eating at night. Eels eat Eel juveniles arrive in coastal waters as The American eel’s slender body is other fish, octopus, shrimps, seaweed, colorless “glass eel” in great numbers, covered with a mucous layer, which makes plankton, crayfish, and other items though with considerable yearly the eel appear to be slimy despite the depending on what is available. With its variation (ICES 2001, p. 2). Glass eels presence of minute scales. A long dorsal relatively weak jaws and many small metamorphose (change) to pigmented fin runs from the middle of the back and teeth, it jerks or pulls on food that cannot “elvers,” that later develop into “yellow is continuous with a similar ventral fin. be consumed whole or readily broken into eels,” which resemble the adults in size Pelvic fins are absent, and a relatively pieces. Holding on with their mouths, and are usually yellow or green in color. small pectoral fin can be found near the adult eels spin their bodies to break apart The timing and duration of yellow eel midline, followed by the head and gill- food, and have been recorded at six to 14 upstream migration depends on latitude covers. Variations exist in coloration; spins per second. In comparison, Olympic and can occur over a broad period of the back may be olive-green to brown ice skaters can spin five times per second. time from January through October. shading to greenish-yellow on the sides Depending on where they cease their and light gray or white on the belly. Eels Wide Distribution upstream migration, some yellow eels from clear water are often lighter than The American eel is found in the Atlantic reach the extreme upper portions of the those from dark, tannic acid streams. Ocean from Greenland to Brazil. Along rivers while others stay behind in the the Atlantic coast of the United States, brackish areas. eels between Maine and Florida are Catadromous? Anadromous? considered part of a single population. Adults reproduce in the sea Something else? American eels begin sexual differentiation The more familiar anadromous Life History at a length of about 20 to 25 centimeters fish, like salmon or striped bass, The American eel begins its life in the (cm) (7.9 to 9.8 inches (in)) and, depending Sargasso Sea near Bermuda within the on eel density, become male or female. are born in freshwater streams, North Atlantic Ocean, where eggs hatch Female eels grow the largest, and any eel travel to the ocean to mature, into larvae that are transported by ocean greater than 33 cm is female. Much later and return to freshwater to currents to the Atlantic coasts of North they make a final change into a mature spawn. Catadromous fish are America and northern South America, stage as “silver eels”, with a distinctive and the Gulf coast. silvery color, and enlarged eyes. Upon born in the ocean, mature in nearing sexual maturity, the eels begin fresh water and return to the American eels are known by several migration back downstream, toward ocean to spawn. American names that describe the coloration of the Sargasso Sea, completing sexual eels are the best example of a progressive stages of development (glass maturation en route. Spawning occurs eel, elver, yellow eel and silver eel) as well in the Sargasso Sea. After spawning, it widespread catadromous fish as changes in where they occur. is assumed that in North American. Other adult eels die. examples include the mountain mullet in the Caribbean. U.S. Fish & Wildlife Service

Habitat in North Carolina The American eel may need federal Some scientists consider the highly protection under the Endangered Species adaptive American eel to have the Act. The US Fish & Wildlife Service broadest diversity of habitats of any fish is conducting a Status Review for the species in the world. In North Carolina, American eel to determine if adding the estuarine areas like the Albemarle- species to the Federal List of Endangered Pamlico Sound provide suitable habitat and Threatened Wildlife is warranted. for the early glass eel and elver stages. Fresh water habitat, including lacustrine Species Contacts in North Carolina areas (lakes and ponds) have historically Elvers, juvenile eels that migrate to brackish R. Wilson Laney, PhD been considered among the most waters and begin to develop gray to greenish- South Atlantic Fisheries Coordinator brown pigmentation. important habitats for eel maturation Credit: Maryland Fishery Resources Office, South Atlantic Fish and Wildlife because eels maturing in such habitats USFWS Conservation Office usually become female. At one time, [email protected] American eels were found throughout 919/515 5019 North Carolina, even described by early Contaminants U.S. Fish and Wildlife Service Toxic substances too, may impair eels, fish collectors as “everywhere abundant” P.O. Box 33683 although which contaminants and how in the upper Catawba River. The Raleigh, North Carolina 27636-3683 American eel finds fresh water habitat much harm they do are as yet largely unknown. Studies have shown American in North Carolina in streams and large Mark Cantrell eels are sensitive to petroleum products, rivers in the Piedmont and Coastal Plain, Fish and Wildlife Biologist and accumulate other contaminants in fat but numbers are reduced upstream of [email protected] cells. many dams. 828/258 3939 x 227 U.S. Fish and Wildlife Service Threats Predation Ashville Field Office Habitat loss and fragmentation In all its life stages, the American eel 160 Zillicoa Street Hydroelectric and other dams block or serves as an important prey species for Asheville, NC 28801 slow movements of elvers and subadult many fish, aquatic mammals, reptiles (e.g., rainbow snakes, snapping turtles) eels to upstream habitats. American eels U.S. Fish and Wildlife Service and fish-eating birds. continue to be distributed throughout Raleigh Field Office the lower areas of watersheds closest to P.O. Box 33726 the sea and sounds. They are prevented Harvest Raleigh, NC 27636-3726 from reaching extreme headwaters where Since the early 17th century, people 919/856 4520 they had historically been reported as have harvested American eel for food www.fws.gov/Raleigh/aeel.html “everywhere common” in 1889 by early and cultural sustenance. American eels scientist D.S. Jordan. continue to support valuable seasonal commercial, recreational and subsistence Turbine mortality fisheries along the Atlantic coast. In the Silver eel females migrating downstream Carolinas, harvest has been greatest for often die in the turbines of hydropower small yellow eels used for bait to catch plants, as a consequence of the eel’s striped bass. Global markets have been long and slender body form, which does volatile, sometimes commanding high not easily pass through turbine blade prices for glass eel exports. openings. Conservation Opportunities Diseases in North Carolina Worm parasites Anguillicolla crassus Eel passage projects have been and Daniconema anguillae may impair completed at the Roanoke Rapids Dam the capacity of the eel to undertake the and similar projects are in different migration to the Sargasso Sea. In one stages of planning and construction. North Carolina study, the percentage of While upstream passage facilities are American eels infected ranged from 10 not present everywhere within the to 100 percent (Moser et al. 2001, p. 1). American eel’s range, more American These worms infest the eel swim bladder. eels are passed into the upper reaches of While it may not be a problem in shallow watersheds now, beginning with renewed water, once the eels mature and begin efforts by fishery scientists in recent their long return swim to the Sargasso, years. a nonfunctioning or even somewhat impaired swim bladder could cause bouyancy and swimming problems in the open ocean, before they have successfully spawned.