June 14,
2004
Page: B1 Section: CONNECTICUT Edition: 6 METRO/SPORTS
FINAL Illustration: PHOTO 1: COLOR; MICHAEL MCANDREWS / THE HARTFORD
COURANT
PHOTO 2: (B&W); MICHAEL MCANDREWS / THE HARTFORD COURANT Source: PETER
MARTEKA; Courant Staff Writer
FISH-POPULATION DECLINES ARE NOT EASILY EXPLAINED
For hundreds of years, alewives have returned to
Long Island Sound each spring to swim up the tidal marshes of Rocky Neck State
Park to Bride Brook in East Lyme.
Exhausted by the mile-long brook
swim, the fish wait for nightfall to leap over a small concrete dam and into
the waters of Bride Lake to spawn.
While the annual spring rite,
known as ``a run,'' still involves thousands of fish, it was once
counted in the hundreds of thousands. The population of river herring --
also known as alewives and blueback herring -- has been shrinking
since 1990, with no hint of a rebound.
Since 2000, the state Department
of Environmental Protection has banned river herring fishing in all
state waterways.
The fish-population declines are
not limited to Connecticut. Rhode Island and Massachusetts officials are seeing
similar drops. While they haven't banned fishing for alewives, some runs
have shut down early because of lack of fish. Some runs, such as
streams and rivers, are natural while others have been built to help the fish
reach their spawning areas.
In Rhode Island, fishermen are
limited to a catch of 24 per week with no fishing on Sundays, Mondays and
Tuesdays.
``Every run in the state is
either stable or declining over the past several years,'' said Phil Edwards, a
principal fish biologist with the Rhode Island Department of Environmental
Management. ``Something is going on, exactly what is unclear.''
Mystery Decline
Alewives are considered the field mice of the ocean and rivers. The
fish provide food for striped bass, bluefish, trout, osprey, bald eagles, great
blue herons, whales, porpoises, tuna and other species.
Anadromous fish species, such as
the herrings and alewives, are born in fresh water and migrate to
the sea, where they grow to adulthood. The fish then return to freshwater
streams and rivers to spawn. The alewives appear in April and lay their
eggs in still waters such as coves and pools. The eggs hatch in June or July.
``These fish play a real crucial role
in the ecosystem. Until we know what's going on, hopefully wise management
practices will help bring them back,'' said Justin Davis, a University of
Connecticut graduate student. For the past two springs, Davis has been studying
the herring runs along Bride Brook in East Lyme
and Whalebone Creek in Lyme's Hadlyme
section to figure out why the numbers have been dwindling.
While Davis said he had hoped to
solve the mystery of the decline, he admits there are probably too many
variables affecting the fish to give a clear answer. Many biologists believe
the resurgence of striped bass along the Eastern Seaboard has been a large
factor in the decline of river herring.
``I'd like to say the increase in
striped bass and its voracious appetite is the silver bullet,'' Davis said.
``But you are talking about a fish [herring] that spends most of its
life in the ocean and returns to fresh water only to spawn and die. Their
habitat is so wide and dynamic, there are so many places where things could be
going on.''
Although the fish are in many
freshwater streams statewide, there isn't much information on run sizes
of river herring. Davis said he hopes the study will help others
estimate run sizes and provide current information about the population
characteristics of the fish in coastal streams and tributaries of the
Connecticut River.
One of the critical monitoring
stations, a fishway at a dam in Holyoke, Mass., has
seen dramatic declines over the past 15 years. In 1985, officials said 600,000 herring
were counted there. But by 1999, that number had declined to 2,699, triggering
the Connecticut ban. The total inched up slightly to 11,000 in 2000, the first
year of the ban. But after repeating the number in 2001, figures plunged again
to 1,900 in 2002 and 1,300 last year, a historic low.
The Holyoke dam and fish lift are
owned by Northeast Utilities. As fish travel north along the waterway from
Connecticut and use the lift, each species is counted by graduate students and
naturalists hired by the utility company. The counts allow biologists in
Connecticut to assess how fish species, including Atlantic salmon, shad and
striped bass, are faring.
Stephen Gephard,
a supervising fisheries biologist with the DEP, hopes the information gathered
during the study will provide data for development of river herring
conservation and restoration plans. In an effort to bolster populations, the
DEP transplants adult herring from streams with healthy runs into
waterways where runs have been eliminated or depleted.
``We don't really fully understand
the causes of the decline and we don't believe fishermen are the problem,'' Gephard said. ``But that's one source of mortality we can
control. We are monitoring streams and restoration projects and just hoping
time is on our side.''
Davis began his study in spring
2003 when he set up a homemade fish weir of tubing and fish net in Bride Brook
and Whalebone Creek. The weir is designed to humanely capture each fish making
the jump from the brook to the pond to lay eggs.
Davis visited the weir each day --
sometimes fighting off cormorants looking for an easy snack -- and counted each
fish before releasing them into the pond. On a spring day in May, Davis along
with three assistants from DEP, spent four hours counting 13,026 fish caught in
the weir. Athough it was a new record for a 24-hour
period, the numbers have dropped off quickly ever since.
Last year, Davis counted 117,128
fish from March 13 to June 30. So far this year, Davis has counted more than
80,000 fish. Those numbers included a few fish regurgitated by a cormorant that
had gotten trapped inside the weir.
``They see it as an
all-you-can-eat buffet,'' Davis said. ``It had eaten so many, it couldn't fly
out. And then it got so stressed out it began throwing up the fish. So I went
all around picking up the fish and counting them.''
During the study, Davis has
noticed the fish are sensitive to water and air temperature as well as water
flow. Once the weather warms up, the run starts to increase. Davis is
also studying scales of fish to determine age and rate of growth and
reproduction.
He also tags the fish to determine
how long they spend in the pond. In the end, Davis hopes to figure out some
sort of formula to estimate the number of fish in the run without having
to count each one.
Caption: PHOTO 1: COUNTING ALEWIVES is a painstaking process
for Kelly Starr, a resource assistant with the state Department of
Environmental Protection. She is helping Justin Davis, a University of
Connecticut graduate student, with his two-year study of river herring.
PHOTO 2: TO STUDY ALEWIVES , first you have to
catch them. Justin Davis, a University of Connecticut graduate student, built a
weir of tubing and fish net to detain the fish temporarily during their annual
migration from Long Island Sound to Bride Lake in East Lyme.
He began his study last year.