The American eel (Anguilla rostrata) has a catadromous life
cycle, that is, it spawns in the ocean and migrates to fresh
water to grow to adult size. As adult eels mature, they leave
the brackish/freshwater growing areas in the fall (August to
November), migrate to the Sargasso Sea and spawn during the
late winter. The Sargasso Sea is a large area of the western
North Atlantic located east of the Bahamas and south of
Bermuda. After spawning, the adult eels die. The eggs hatch
after several days and develop into a larval stage (leptocephalus)
which is shaped like a willow leaf. The larvae drift in the
ocean for several months and then enter the Gulf Stream current
to be carried north toward the North American continent. As
they approach the continental shelf, the larvae transform into
miniature transparent eels called “glass eels”. As glass
eels leave the open ocean to enter estuaries and ascend rivers
they are known as elvers. This migration occurs in late winter,
early spring, and throughout the summer months. Some elvers may
remain in brackish waters while others ascend rivers far
inland. Eels may stay in growing areas from 8-25 years before
migrating back to sea to spawn.
There are three distinct
fisheries for eels in Maine which relate to three different
life stages. The glass eel/elver fishery harvests small eels
returning to rivers from their ocean spawning areas. This
fishery utilizes fine mesh fyke nets (a funnel shaped net) or
dip nets to collect elvers as they ascend to fresh water. The
yellow eel fishery occurs for eels which are growing in
brackish and fresh waters. These eels are typically more than
2-3 years old, but not yet mature. Harvesting gear in this
fishery includes baited eel pots and fyke nets. The silver eel
fishery occurs in late summer and fall and consists of weirs
across streams and rivers to collect out migrating sexually
mature eels that are moving downstream to go to the Sargasso
Sea to spawn. Fisheries for yellow and silver eels have a long
history in Maine, having occurred since the earliest colonial
settlements. The elver fishery is relatively recent, having
begun in the early 1970’s to 1978 and recommenced in the
early 1990’s. The fishery was nonexistent from 1979 to the
early 1990’s due to a collapse in market demand for elvers.
In the past three years, market demand has increased
dramatically. Elvers are highly valued in the far east (Japan,
China, Taiwan, and Korea) where they are cultured and reared to
adult size for the food fish market. Due to recent intense
market demand, elvers have now become the most valuable marine
resource in terms of price per pound which varies from $25 to
$350. The fishing season for elvers is restricted to March 22
through May 31. Harvest methods are restricted to hand dip net
and fyke nets with no more than two fyke nets allowed per license
holder, depending on the license holder's history. Concerns about elver fishing relate to impacts
of fyke nets on other species migrating and spawning (smelt,
alewives, trout and salmon) in Maine rivers, potential over
harvest of eels, and the significance of eels to the ecosystem.
Dr. Gail Wippelhauser and George Zink Jr. are monitoring the Maine elver fishery to collect information on the harvest and fishing effort, bycatch of other species in elver nets, and the impact of this fishery on adult eel abundance in Maine waters. In addition, DMR has funded a number of eel research projects with the University of Maine at Orono to investigate various life history aspects of the American eel.
For more information on the eel and elver fishery,
Dr. Gail Wippelhauser may be contacted at: (207)624-6349
-or-
E-mail at:
