D. Anthropogenic Impacts on American Eel
1. Upstream Passage at Dams
Female American eels spend most of their lives in freshwater habitat along
the Atlantic seaboard prior to returning to the Sargasso Sea to give birth.
Safe and efficient access for juvenile eels to their freshwater habitat
is essential to the survival of the American eel. Coastal river systems
along the Atlantic seaboard are the sole migratory pathways for female American
eels to gain access to their required freshwater habitat.
ASMFC (2000) states: "By region, the potential habitat loss [for American
eel] is greatest (91 percent) in the North Atlantic region (Maine to Connecticut)
where stream access is estimated to have been reduced from 111,482 kilometers
to 10,349 kilometers of stream length. Stream habitat in the Mid Atlantic
region (New York through Virginia) is estimated to have been reduced from
199,312 km to 24,534 km of unobstructed stream length (88 percent loss).
The stream habitat in the South Atlantic region (North Carolina to Florida)
is estimated to have decreased from 246,007 km to 55,872 km of unobstructed
stream access, a 77 percent loss."
The Maryland Department of Natural Resources, MBSS Newsletter March 1999,
Volume 6, Number 1 states:
"The most dramatic example of the decline of American eel abundance
is dam construction on the Susquehanna River. Prior to the completion of
Conowingo and three other mainstem dams in the 1920's, eels were common
throughout the Susquehanna basin and were popular with anglers. To estimate
the number of eels lost as a result of construction of Conowingo Dam, we
used MBSS data on American eels from the Lower Susquehanna basin and extrapolated
it to the rest of the basin above the dam. Our best conservative guess is
that there are on the order of 11 million fewer eels in the Susquehanna
basin today than in the 1920s.
"The magnitude of this loss is corroborated by the decline in the
eel weir fishery in the Pennsylvania portion of the Susquehanna River. Before
the mainstem dams were constructed, the annual harvest of eels in the river
was nearly 1 million pounds. Since then, the annual harvest has been zero.
Given the longevity of eels in streams (up to 20 years or more) and their
large size, the loss of this species from streams above Conowingo Dam represents
a significant ecosystem-level impact. Because adult eels migrate to the
Sargasso Sea to spawn and die -- transporting their accumulated biomass
and nutrient load out of Chesapeake Bay -- the loss of eels has increased
nutrient loads in the basin and reduced them in the open ocean where they
are more appreciated."
2. Downstream Passage at Dams
Female American eels spend 20 to 50 years in freshwater habitat along the
Atlantic seaboard before returning to the Sargasso Sea to give birth. Safe
and efficient access for pregnant female American eels from their freshwater
habitat to the Atlantic Ocean is essential for female American eel to give
birth in the Sargasso Sea. Coastal river systems along the Atlantic seaboard
are the sole migratory pathways for female American eels to gain access
to their oceanic spawning grounds.
Records of severe kills of female American eels by the turbines of hydro-mechanical
and hydroelectric dams exist since as early as the 1880s. A corporate history
of the S.D. Warren Paper Company describes severe kills of female American
eels at the company's dam at Ammoncongin Falls on the Presumpscot River,
Maine during the 1880s. The Presumpscot River is the outlet of Sebago Lake,
the second largest lake in Maine. The dam at the outlet of Sebago Lake has
long been called the Eel Weir Dam. The S.D. Warren corporate history states
at page 46:
"Water power had its peculiar troubles: every cold winter morning
anchor ice would clog in the intakes, and the mill would be down. Then
when warm weather came, the water would be full of eels and eels are fish
with tough hides. The blades of the water wheels would not chew them up
and there are frequent entries in the record stating the water supply had
failed and the mill was down, because the eels had stopped the wheels."
One hundred years later, a similar report was made in 1996 by the operator
of the Damariscotta Mills hydro-electric dam on the Damariscotta River in
Newcastle, Maine to Lewis Flagg of the Maine Department of Marine Resources.
A telephone record by Alex Hoar of the U.S. Fish and Wildlife Service, dated
March 30, 1996 states:
"Subject: Eels
Telephone Record.
Lew Flagg told me in a telephone conversation on Saturday night that eels
had stopped the project at Damariscotta Mills from operating and set off
the alarm. He was told this by the plant operator. The event happened in
October. He said the eels clogged the project as they were migrating downstream.
Alex Hoar."
Hydro-electric dams located on the coastal watersheds of the Atlantic seaboard
are a major source of mortality for female American eel as they attempt
to migrate from freshwater to the Sargasso Sea to give birth. Of 15,570
dams blocking American eel habitat in the United States, Busch et al. (1998)
reported that 1,100 of these dams are used for hydroelectric power. To Petitioners'
knowledge, virtually none of these 1,100 hydroelectric dams provide safe
passage for migrating female American eel. As a result, downstream passage
by female American eels at these dams is via the project turbines, which
results in the death of virtually all female eels attempting to migrate.
Radio tagging studies of migrating female American by the Maine Department
of Marine Resources at two hydro-electric dams in Maine indicate nearly
100 percent of adult female eels entering project turbines are killed or
severely injured and, therefore, unable to complete their spawning migration
(MDMR 2002).
ASMFC (2000) states: "Downstream passage to the American eel's historic
habitat is just as important as successful upstream access. Therefore, turbine
induced mortality during downstream passage needs to be resolved since it
impacts prespawning adult silver eel."
A summary of two meetings held with Maine commercial eel fishermen in December,
1994 written by State of Maine fisheries biologist Frederick W. Kircheis
states:
"Many eel harvesters commented on the loss of large numbers of
migrating eels at power generating turbines on rivers. Apparently eels are
attracted to the current drawn by the turbines while migrating at night.
One eel weir operator has, as result of legal action, an agreement with
a dam operator to cease generating after dark from mid-August to mid-October,
the prime time for migrating eels."
Petitioners have direct experience with the magnitude of mortality to female
American eel caused by hydro-electric dam turbines.
In recent years, severe kills of migrating adult American eel have been
repeatedly documented by the Petitioners and the Maine Department of Marine
Resources at the American Tissue hydro-electric dam on Cobbosseecontee Stream
in Gardiner, Maine. This stream is a major tributary of the Kennebec River
located 25 miles below the confluence of the Sebasticook and Kennebec Rivers.
Spillway passage is available for American eel at the American Tissue Project.
However, annual fish kills of female American eel demonstrate that most
migrating American eel select the American Tissue Dam turbine intake as
their migration route, rather than the dam spillway. This has caused significant
annual entrainment and death of American eel in the project turbines since
the dam was redeveloped for hydroelectric power in 1978. In 2002 and 2003,
American eel kills at this dam were only stopped after protests by the Petitioners
and others forced the dam owner to institute dusk to dawn turbine shutdowns
at the American Tissue Project during the fall silver eel migration season.
Reconstruction of the Pumpkin Hill hydro-electric dam on the Passadumkeag
River in Lowell, Maine was documented to cause severe kills of migrating
adult American as soon as the project began operation in 1987. Commercial
silver eel harvests in the Passadumkeag River below the dam declined from
a 16-year average of 10,000 pounds per year to 2,500 pounds upon activation
of the Pumpkin Hill project turbines in 1987. The commercial eel fisherman,
Mr. Gerald Crommett of Passadumkeag, Maine, stated in a Nov. 4, 1987 letter
to the Maine Department of Marine Resources: "I feel the only eels
we caught [this year] were from the waters of Cold Stream Ponds, which are
below the dam." Mr. Crommett further stated: "We were never notified
of the building of this dam in Lowell. The way to overcome this problem
would be to close the power dam down from Aug. 15 to Oct. 15. We expect
to be compensated for our loss from someone responsible for this."
After threats of legal action by Mr. Crommett, the dam owner began evening
turbine shutdowns at the Pumpkin Hill project during the fall eel migration
season.
Radio-tracking of adult American eels by the Maine Department of Marine
Resources just above the Lockwood hydro-electric project on the Kennebec
River during fall 2002 indicates that 40 percent or more of the adult American
eel attempting to migrate past the Lockwood Project each fall are entrained
and killed in the Lockwood Dam turbines, despite the availability of the
project spillway for passage (MDMR 2003).
Radio-tracking of adult female American eels by the Maine Department of
Marine Resources (Maine DMR) at the Benton Falls Project in 2000 and 2001
indicate more than 50 percent of the migrating eels attempting to pass the
Benton Falls project are entrained and killed in the project turbines. The
studies also found that 100 percent of the eels entrained in the Benton
Falls project turbines were killed by them. In fall 2001, Maine DMR staff
used an underwater videocamera at the Benton Falls Project turbine outfall
to attempt to locate two radio-tagged eels which had passed through the
Benton Falls Project turbines. The videocamera revealed large numbers of
dead eels and eel carcasses resting on the river bottom at the turbine outfall.
Maine DMR's 2001 study reported stated:
"DMR personnel attempted to recover these eels on five occasions (10/22,
10/26, 10/31, 11/2, 12/7). An underwater camera revealed a deep hole below
the tailrace that contained many portions of eel carcasses in various states
of decay. It was apparent these eels had been killed by turbine blades ....
Based on two years data, the surface bypass at Benton Falls is not efficient
at passing eels."
In October 2004, Petitioners documented a large and severe kill of migrating
female American eel at the Benton Falls hydro-electric dam on the Sebasticook
River in Benton, Maine. The Sebasticook River is a large (970 square mile)
tributary of the Kennebec River.
The kill was first observed and documented by Douglas Watts of Friends
of the Kennebec Salmon at 6:45 a.m. on October 14, 2004. Mr. Watts observed
and photographed 25-30 large female American eels in various states of decomposition
on the river bottom immediately below the Benton Falls Project turbine outfall.
All of the eels bore wounds and injuries indicative of turbine blade strike
(ie. decapitation, severed and partially severed torsos). Most of the eels
observed were 3-4 feet in length. Four bald eagles were observed directly
below the dam actively feeding on decapitated eels. Mr. Watts collected
two large freshly killed eels to display for officials of the Maine Department
of Environmental Protection and the Maine Department of Marine Resources.
During these collection efforts, two employees of Benton Falls Associates
working at the dam were shown the eels by Mr. Watts. Mr. Watts informed
the employees the decapitated eels had been killed by the dam turbines and
were just a small fraction of those he had just observed lying dead on the
river bottom below the dam. One Benton Falls Associates employee told Mr.
Watts the eels were killed by seagulls, not the dam turbines. One employee
informed Mr. Watts that he was trespassing. Project turbines were running
at the time of Mr. Watts' visit to the site and there was no spill at the
dam. All river flow was exiting through the project turbines and the surface
bypass for juvenile alewives and shad. Despite that the surface bypass was
in operation at the time of his visit, Mr. Watts observed and photographed
numerous freshly decapitated juvenile alewives below the dam as well.
All photographs taken can be viewed at www.kennebecriver.org.
On Friday, October 15, 2004 Mr. Nathan Gray of the Maine Department of
Marine Resources accompanied Mr. Watts to the Benton Falls project to perform
a more thorough survey of the project tailrace for dead and injured American
eel. Using chest waders and dip nets, Mr. Gray and Mr. Watts surveyed the
wadeable portions of the Sebasticook River for a distance of approx. 300
yards below the Benton Falls Project. The survey lasted approximately 90
minutes with visibility hampered by dark, overcast skies. During the October
15 survey, Mr. Gray and Mr. Watts captured several very large eels that
had been struck by the dam turbines the previous evening and were still
barely alive but so wounded they could not avoid being captured or swim
correctly. These were eels that would not have been killed had Mr. Calvin
Neal of Benton Falls Associates shut down the project turbines when first
alerted to the killing of eels at the dam by Mr. Watts at 8 a.m. the day
before.
Mr. Gray's October 15, 2004 report to his superiors reads as follows:
"-----Original Message-----
From: Gray, Nate
Sent: Friday, October 15, 2004 4:09 PM
To: Squiers, Tom; Wippelhauser, Gail; Glowa, John M
Subject: Benton Eel kill
Returned to the tailrace of Benton Fall Hydroelectric facility this PM with
Doug Watts after he reported a significant eel kill having happened sometime
prior to 10/14/04. Using chest waders we inspected the tailrace outfall
and found there were at least a few hundred eels killed over the past few
weeks. Eels ranged from highly decomposed to cripples unable to
swim. A bald eagle was noted taking off with eel remains. Nearly all sections
of the tailrace that were wadeable contained the remains of adult eels that
appeared to have been killed by turbine blade strike. Calvin Neal, the
station operator had reduced flows to the turbine in order to more efficiently
utilize water resources in generating electricity. This may account for
the eels that were found that appeared whole but were nevertheless dead.
On 10/14/04 I performed a routine downstream inspection of the site and
was informed by Mr. Neal that a certain person in the form of Douglas Watts
had come to the site and was very upset that there were dead eels below
the project. I asked Mr. Neal to accompany me on an inspection walk down
in the tail waters to see if there were any eels or alewives that had been
entrained and killed by the turbine. Viewing conditions were less than ideal
but I did note that there appeared to be a few dead eels in the tailrace.
One in particular was quite visible. Having no chest waders with me I
told Mr. Neal that I would return on 10/15/04 to confirm the presence of
the eel(s) in the project tailwaters. Mr. Watts visited the office on the
morning of 10/15/04 and told what he had seen below the Benton facility
so I asked him to accompany me to show me what he had seen. He did so.
There were more than he had seen the previous day. Below the rapids there
is a large fall-out pool and the bottom here showed eels in various states
of decay from very fresh to weeks old."
Immediately after this October 15, 2004 inspection, Mr. Gray informed Mr.
Calvin Neal, the dam operator, that the river bottom below the dam contained
several hundred dead eels which had been recently killed by the project
turbines. Despite being provided with this information, Mr. Neal did not
offer to shut down the project turbines.
On August 20, 2004 Petitioners filed a motion before the Federal Energy
Regulatory Commission requesting the Commission require the Benton Falls
Dam owner to provide safe passage for female American eels at the dam during
the fall 2004 eel migration season. The Commission refused.
On October 16, 2004 Petitioners and Friends of Merrymeeting Bay filed complaints
before the Federal Energy Regulatory Commission of an ongoing severe kill
of female American eels at the dam and requested the Commission require
the Benton Falls dam owner provide safe passage for female American eels
for the remainder of the fall eel migration. The Commission refused.
On October 18, 2004 the State of Maine informed Petitioners it had no legal
authority to stop the ongoing killing of female American eel at the Benton
Falls dam.
On October 19, 2004 the State of Maine asked the Benton Falls dam owner,
Arcadia Energy of Atlanta, Georgia, to conduct voluntary evening turbine
shutdowns at the dam for the remainder of the fall 2004 American eel migration
season. The dam owner refused.
The website of the Benton Falls dam owner, Arcadia Energy, (www.arcadia-energy.com)
states:
"We are committed to developing renewable hydroelectric power and
green power while responsibly guarding and maintaining precious natural
resources."
The turbines of the Benton Falls dam have remained operating and killing
pregnant female American eels during the entire fall 2004 eel migration
season, as they have annually each fall since the Benton Falls dam went
on-line in 1987.
Petitioners have been informed by staff of the U.S. Fish & Wildlife
Service that large kills of migrating female American eel have been documented
in recent years by USFWS staff at the Holyoke Dam, the lowermost hydro-electric
dam on the Connecticut River (Alex Haro, USFWS, personal communication to
Timothy A. Watts, October 2004). The Connecticut River is the largest watershed
in New England. To the Petitioners knowledge, no provision for safe passage
of migrating female eels is provided at the Holyoke Dam or any other hydro-electric
dam in the Connecticut River watershed.
3. Toxic Contaminants
ASMFC (2000) states:
"American eel are benthic, long-lived and lipid rich. Therefore, American
eel can accumulate high concentrations of contaminants, potentially causing
an increased incidence of disease and reproductive impairment as is found
in other fish species (Couillard et al. 1997). An analysis of the contaminants
in migrating silver eel in the St. Lawrence River showed that the highest
concentrations of chemicals were in the gonads. Concentrations of PCB and
DDT were found to be 17% and 28% higher in the gonads than in the carcasses.
The chemical levels in the eggs could exceed the thresholds of toxicity
for larvae. Also, since the migrating females are not feeding, the chemical
levels in the eggs could be even higher at hatching, increasing the likelihood
of toxicity to the larvae (Hodsdon et al. 1994)."
4. Human Harvest
Throughout their range in North America and the United States of America,
American eel are intensively harvested at all life stages (glass eel, elver
eel, yellow eel and silver eel) upon their entering coastal and freshwater
habitats in the United States of America.
ASMFC (2000) states:
"Since the early 17th century, Native Americans have harvested eel
for food and cultural sustenance. Today, commercial and recreational fisheries
for American eel are seasonal, but remain economically important by providing
both direct and indirect employment ... Since the fishery's peak in the
mid 1970s at 3.5 million pounds, commercial landings have declined significantly
to a near record low of 868,215 pounds in 2001. Recreational data concerning
eel harvest appears to indicate a decline in abundance. According to the
NMFS Marine Recreational Fisheries Statistics Survey, recreational harvest
in 2001 was 10,805 eel, a significant decrease from the peak of 106,968
eel in 1982."
Geer (2004) stated: "U.S. landings on the Atlantic Coast are down
about 64 percent of the long-term average back to 1950, almost 44 percent
below the 20-year average and about 30 percent below the five year average.
This is based on 2002 landings reports."
NEXT