Hi Tweets! Here's an interesting little bit of information.

Peggi
>>
>>>From "C-paper" Updates at <http://www.linkny.com/~civitas> January
>>>18,
>1998
>
>WAR DECLARED ON CORMORANTS
>
>A triple pincer movement threatens
>>>to roll back population gains made by
>double-breasted cormorants since
>>>they were almost wiped out in the early
>1900's and suffered serious
>>>setbacks to their recovery from water pollution
>in the 60's and
>>>70's.
>
>Human fishers regard these aquatic, fish-eating birds as
>>>serious
>competitors for their finned prey. Many human hunters look
>>>forward to
>being granted a new species on which to test their
>>>marksmanship while at
>the same time performing a service for fishers.
>>>Fish farmers, commercial
>fishers, charter boat captains and state game
>>>agencies that stock fish to
>enhance the success of those who buy fishing
>>>licenses all take a dim view
>of birds who gobble up their product. The
>>>result is pressure to remove
>these prehistoric birds from their protected
>>>status under the Migratory
>Bird Treaty Act.
>
>There is no doubt that
>>>cormorants, also known as shags, catch and eat a
>lot of fish, but it is
>>>necessary to consider the number of fish they catch
>in relation to the
>>>number of fish taken by humans and other species.
>According to the U.S.
>>>Fish & Wildlife Service (USFWS), worldwide studies
>have shown that
>>>cormorants consume "generally less than 5 percent of the
>quantity caught
>>>by commercial or sport anglers". Most of the fish they
>catch are "rough"
>>>fish as opposed to the species coveted by human fishers.
>Analysis of
>>>stomach contents of cormorants in Arkansas found that
>"sport-fish"
>>>comprised 1 percent of their diet.
>
>A Lake Ontario survey placed the
>>>percentage of trout and salmonids consumed
>by cormorants even lower -- at
>>>3 tenths of 1 percent (.003). In response
>to concern that cormorant
>>>catches would deprive "sport-fish" of food, a
>survey in Western Lake Erie
>>>found that the number of fish caught by
>cormorants was "only about 1
>>>percent of the prey-fish biomass needed to
>support populations of the
>>>walleye, a valuable ''sport-fish'." Similar
>results were obtained in
>>>studies conducted on Lake Superior.
>
>The USFWS report concluded: "Based
>>>on a review of the best scientific
>evidence, it does not appear that a
>>>strategy of reducing cormorant
>populations to benefit "sport-fish"
>>>populations is biologically warranted."
>
>The National Audubon Society
>>>agrees. In a letter dated January 12, 1998,
>Greg clouser wrote on
>>>Audubon's behalf: "There is absolutely no science to
>back their (sport
>>>fishing groups') claims.
>
>Cornell University conducted a study of the
>>>cormorants on Oneida Lake, near
>Syracuse, New York, where their
>>>population had soared from none as recently
>as 1982 to 250 nesting pairs
>>>in 1997. By mid or late September, there were
>an estimated 2,500
>>>cormorants on the lake as the resident cormorants and
>their offspring
>>>were joined by migrating birds from farther north.
>
>Graduate students
>>>engaged in the study estimated that residents and
>migrants combined
>>>consume 40 metric tons of Oneida Lake fish a year. This
>seems like a
>>>vast amount until you compare it with the 207 metric tons
>consumed by
>>>walleyes, a favorite catch of sport fishers. Competition
>between the two
>>>species did not appear to be intense. The dietary staple
>of both species
>>>was yellow perch but the walleyes consumed mostly fry and
>fingerlings
>>>while the cormorants preferred larger, year-old fish. These
>preferences
>>>have the effect of giving the walleyes first crack at this
>preferred
>>>species in Oneida while the cormorants dine on their leftovers
>after they
>>>have grown to a larger size.
>
>These modern studies confirm a 1915
>>>assessment by the Canadian Geological
>Survey that showed cormorants were
>>>not eating young salmon as feared by
>commercial and sport fishers, but
>>>rather "coarse fish" like sculpins,
>cunners, gunnels and eels, i.e. fish
>>>with little or no commercial value.
>
>In spite of the lack of evidence
>>>that cormorants have an unfavorable impact
>on sportfishing, and
>>>considerable evidence that they do not,
>Representatives John McHugh
>>>(R-NY) and Rep. Collin Peterson (D-MN)
>announced their intention to
>>>introduce legislation establishing hunting
>seasons for double-crested
>>>cormorants in order to reduce loss of fish
>stocks and interference with
>>>recreational and commercial fishing.
>
>New York State Assemblyman Michael
>>>Bragman convened a cormorant management
>meeting in Syracuse on October
>>>16, 1997. Participants "almost uniformly
>described the devastating
>>>ecological, economic, and social impacts of
>cormorant predation on Lake
>>>Ontario and Oneida Lake fisheries, local
>businesses, and surrounding
>>>communities." Their testimony led Bragman to
>call for a cormorant
>>>management plan to be formulated before the 1998
>spring migration. He
>>>voiced the opinion that New York's fishing-related
>tourism deserves as
>>>much consideration as southern fish farms, which can
>get permission to
>>>shoot cormorants.
>
>This is true, but only after non-lethal methods to
>>>discourage cormorants
>from preying from fishing in their ponds have
>>>ceased to be effective.
>They have permission to shoot only those
>>>cormorants actually preying upon
>or "about to prey upon" their fish.
>>>Experience has shown that non-lethal
>methods such as noisemakers regain
>>>their effectiveness -- for a time at
>least --after birds have been killed
>>>or wounded there.
>
>It is understandable that fishers, who have observed
>>>cormorants gobbling up
>a school of hatchery fish as soon as it has been
>>>released and even those
>who have watched cormorants dive and come up with
>>>a meal while their hooks
>remain empty, feel that the cormorants are
>>>depriving them of success. It
>might help them to understand if they were
>>>to read some of the studies
>instead of listening to each other's tales
>>>of righteous indignation.
>
>Fish and wildlife officials have already
>>>developed ways of releasing fish
>to avoid cormorant predation. One
>>>method is simply to release the young
>fish in areas removed from
>>>cormorant activity. If this is not possible, as
>in a smaller lake, the
>>>fish can be released after dark when the cormorants
>are sleeping. This
>>>works well for rainbows who have to be released in
>streams. Another
>>>tactic is to make the released before the cormorants
>return north in the
>>>spring.
>
>Another method being pursued by the Oswego Chamber of Commerce
>>>and charter
>boat captains is a "net pen" to keep the cormorants from
>>>getting at the
>young fish. After the fish have had time to acclimate,
>>>the captains tow
>the pen out into the lake away from cormorant-frequented
>>>areas when it is
>time to release the fish.
>
>Cormorant populations, which
>>>have begun to level out in the Great Lakes,
>are controlled to some extent
>>>by the number of nesting sites available to
>them. Adults who are not
>>>successful in commandeering a site either don't
>breed or move
>>>elsewhere.
>
>These communal nesting sites have given fishers reason to
>>>complain
>eloquently about the odor caused by the elimination of digested
>>>fish, which
>does no harm when these sites are not next door to human
>>>habitation as is
>usually the case. Cormorants can be discouraged from
>>>nesting next door by
>clearing away their nesting material.
>
>There is
>>>another side to cormorant excretions, however. On islands off the
>coast
>>>of Peru where 10 million cormorants congregate, their droppings
>>>are
>called guano and are harvested as what horticulturists consider to be
>>>the
>world's finest organic fertilizer. The moister climate of the Great
>>>Lakes
>region does not permit the accumulations found in Peru, but the
>>>nitrates
>and phosphates that wash into the water can help counteract the
>>>effect of
>the zebra mussels by nourishing diatoms and algae that are the
>>>food base of
>all aquatic life.
>
>It has been suggested that the larger
>>>cormorant population may interfere
>with other protected birds. They may
>>>have displaced black-crowned night
>herons in one instance. Should this
>>>become a problem, the cormorants' eggs
>can be addled by shaking them or
>>>dipping them in oil to prevent them from
>hatching. This method will
>>>limit local populations to existing adults
>which seems much more sensible
>>>than shooting cormorants everywhere to make
>a difference on a particular
>>>island. It also has the advantage of
>preventing new birds from moving in
>>>after the original occupants have been
>killed.
>
>Wildlife populations
>>>will generally sort such matters out for themselves,
>however, as they did
>>>eons before modern humans started to interfere with
>their innate
>>>population determinants.
>
>The issue for fish farms is different. Unlike
>>>the perceived loss to
>fishers, theirs is a real one. Ironically they
>>>brought it on themselves by
>laying out a banquet that attracted
>>>fish-eating birds and may well have
>contributed to the rise in population
>>>by increasing their food supply. The
>present policy of USFWS (granting
>>>exemptions to kill cormorants in the act
>of fishing in these ponds after
>>>other aversive methods have become
>ineffective) seems like the best
>>>solution for the present. The ultimate
>solution is for these artificial
>>>enterprises, which contribute to water
>pollution by keeping fish crowded
>>>fin to fin, to be shut down. As that
>will not happen this year or next,
>>>it seems best to separate their needs
>from the needs of those who seek to
>>>establish a sport hunting season on
>cormorants.
>
>>>-30-
>
>Useful addresses:
>Commissioner John
>>>Cahill, Department of Environmental Conservation
>50 Wolf Road, Albany NY
>>>12250;
>
>Paul Schmidt, Chief, Office of Migratory Bird Management, USFWS,
>>>Arlington
>Square,
>4401 North Fairfax Drive, Arlington VA 22204
>
>>
>
>Mary D. Reynolds, Executive Director
>International Wildlife Rehabilitation Council (IWRC)
>4437 Central Place, Suite B-4
>Suisun City, California 94585, USA
>707-864-1761/Fax 707-864-3106
>e-mail: iwrc at inreach.com
>website: iwrc-online.org
>
>
>
>
>
>
>
>
Ben & Peggi Rodgers
Aptos, CA (near Santa Cruz 122 W, 37 N)
USA
woodduck at cruzio.com
http://www2.cruzio.com/~woodduck/


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