March/April 1997
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March/April 1997 |
by Alfred L. Meister and Lewis N. Flagg
The American eel (Anguilla rostrata) supports a small but valuable fishery along the East Coast of North America. Eel harvests in the State of Maine and maritime provinces have risen and fallen at different times this century. While not certain, the lower harvests in recent years may be the result of overfishing of young and adult eels in the mid-1970s.
Adult eels are air freighted to markets in Europe and young eels, called elvers, are shipped in water and oxygen filled containers to aquaculturists in the Far East. A small domestic market for adult eels exists in both Canada and the United States.
In North America, the species is a single breeding population whose offspring inhabit fresh water streams and rivers, lakes and ponds, estuaries, bays and the open ocean. Spawning occurs in the Sargasso Sea of the Atlantic Ocean in winter or early spring. Eggs hatch in about two days as a long-lived larval stage that swims or drifts in the upper 300 meters (300 yards) of the ocean for several months. They undergo a metamorphosis and now resemble miniature transparent eels called "glass eels." These transparent juveniles enter estuaries and ascend the streams during the late winter and early spring, 12-14 months after hatching. Glass eels and pigmented juveniles soon develop into the "yellow" eel stage with a dark back and a yellowish under surface. After eight-24 years in the nursery area, they approach reproductive maturity and become white or silvery on the under surface and migrate seaward.
Traditionally only the yellow and silver stages of the eel were fished, primarily for food, using such gear as baited pots, hooks, spears, traps and weirs. Historically annual eel landings in the State of Maine ranged from a few pounds to a high of 180,000 kilograms (400,000 pounds) in 1912. By 1935 annual landings had declined below 45,000 kilograms (100,000 pounds). For the period 1950-1970, average annual landings were 16,000 kilograms (36,000 pounds -- see Chart, page 26). From 1971-1980, eel landings increased dramatically averaging 52,000 kilograms (116,000 pounds) annually. Landings have remained at substantially lower levels since 1980. Silver and yellow eel landings for the Maritime Provinces of Canada, based on market demand and economic values of the fishery, were assumed to be at least one-third of the Maine landings for comparable time periods.
From 1972 to 1978 a large fishery developed for elvers, mostly the unpigmented glass eels. Using small meshed seines, fyke net and hand held dip nets, this fishery collapsed in 1978 and only a small elver fishery persisted until 1994. State landing data did not separate the larger eels from elvers until 1994. However, based on limited data on elver landings, the estimated harvest was 10,000 kilograms (23,000 pounds) in 1977 and 7,600 kilograms (17,000 pounds) in 1978. This represents an enormous number of individuals since there may be 5,500 elvers per kilogram compared to about two adult eels per kilogram. The recent decline in eel landings, with 1981-1994 average annual landings of 12,000 kilograms or 27,000 pounds, may have resulted from a combination of overfishing of the adult stocks (yellow and silver eels) and a reduction in recruitment due to the heavy elver harvest in the mid-1970s. Considering that eels require a growing period of eight-24 years to reach sexual maturity, the significant time lapse that occurred is consistent with what one would expect before the symptoms of over exploitation become apparent. The harvesting of multiple life stages also increases the probability of over exploitation.
| Year | Landings (kg) | Value ($US) | |||
|---|---|---|---|---|---|
| Canada | Maine | Total | Av./Kg | Total | |
| 1989 | 26 | * | |||
| 1990 | 174 | ||||
| 1991 | 65 | ||||
| 1992 | 227 | ||||
| 1993 | 713 | ||||
| 1994 | 1574 | 3333 | 4907 | 110 | $ 539,770 |
| 1995 | 3238 | 7529 | 10767 | 507 | $5,458,869 |
| 1996 | 2862 | 4617 | 7479 | 353 | $2,640,087 |
Commercial quantities of elvers first arrive in the estuaries in late March, peak in May and decline to a negligible abundance by mid-June. The landings for Canada, primarily New Brunswick and Nova Scotia, and the State of Maine are presented in the accompanying table. Canadian figures for the elver fishery show a rise from 26 kilograms in 1989 to 3,200 kilograms in 1995, dropping to 2,900 kilograms in 1996. State of Maine landing were 3,300 kilograms harvested in 1994 and 4,600 kilograms in 1996. Combined elver landings peaked in 1995 with 11,800 kilograms harvested.
The economic impact for coastal areas has been significant. Prices ranged from $100-300 (US) per kilogram in 1994 with an average price of $110. In 1995 the average price escalated to $500 per kilogram with some early catches bringing over $800 (US)per kilogram. Total value of the elver fishery in 1995 and 1996 estimated at $5.5 million and $2.6 million respectively.
It may be noted that in the table approximately one-half of the landings reported are from Maritime Canada. This figure may increase as areas outside the Bay of Fundy and eastern Nova Scotia are opened to fishing. There is interest in the Miramichi area of New Brunswick and concern on the part of Quebec over the apparent precipitous decline in the number of eels entering the St. Lawrence. The fishery is not expected to show a major increase in harvest or effort in Maine. Overharvest of the American eel resources of Canada and the United States may or may not be a reality. Recruitment for species consisting of one population is poorly understood.
It is apparent that the harvest of silver and yellow eels has declined in recent years. Is this decline due to exploitation, or, is it a natural cyclic phenomenon? Time will tell!
Fortunately for the eel, most commercial species are not harvested to extinction. It becomes a purely economic situation where costs per unit harvested dictates the landings and effort expended. Our boundary waters and common ecosystems are complex biological entities. Eels eat and are eaten by a host of organisms ranging from man and the majestic eagle to a multitude of finned, furred and feathered creatures. What happens to one member of an ecosystem frequently has a ripple effect whose consequences are difficult to project.
sommaire
La pêche à l'anguille dans le Maine et au Canada atlantique a connu des hauts et des bas au cours du XXe siècle. Il est possible que la baisse des prises au cours des dernières années soit causée par une surpêche des anguilles jeunes et adultes au milieu des années 70.
La pêche aux anguilles jaunes et argentées est moins productive depuis quleques années. Cette diminution est-elle causée par l'exploitation, ou s'agit d'un phénomène cyclique naturel? Seul le temps nous le dira!
Alfred L. Meister is a fishery scientist and member of the International Joint Commissions Pollution Advisory Board for the St. Croix River. Lewis N. Flagg is the director of Stock Enhancement Division, Maine Department of Marine Resources. Brian M. Jessop of the Department of Fisheries and Oceans in Halifax, Nova Scotia contributed the Canadian catch data used in this article. For more information, contact Alfred L. Meister, 19 Sewall Drive, Old Town, ME 04468.
Revised: April 14, 1997
Maintained by Kevin McGunagle,
mcgunaglek@ijc.wincom.net