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PINNIPEDS
CRESLI
Seal Research
Program
The Coastal Research & Education Society of Long Island's (CRESLI) Seal
Research Program monitors seal populations and conducts long term behavioral
studies of seals around Long Island. This includes regular observations at
major haul out sites around Long Island. Population counts over the last 10
years have indicated a dramatic increase in the number of seals utilizing
Long Island's waters, as well as a shift in the species composition of the
region. Historically, Long Island's seal species typically
included
Harbor and
Grey seals, which are relatively abundant in our waters from late fall
until late spring. In recent years, "arctic" species such as
Harp,
Hooded and
Ringed seals
that were once extremely rare for Long Island, have also become more
commonly sighted.
Seal surveys are conducted using aerial and shipboard platforms
concurrently in order to assess the accuracy of each count. During aerial
surveys two population estimates are produced. First a visual estimate is
made by observers in the aircraft. Subsequently, film taken from the
aircraft is developed and examined under a microscope to arrive at an actual
count. Differential counts are made for animals at or above the water's
surface and below the surface, producing an accurate count. The shipboard
surveys produce an estimate by counting and photographing the animals. The
shipboard surveys are subsequently used to assess the sex ratio and age
composition of the animals at these sites. Based upon the studies conducted
by CRESLI's scientists there are 26 sites around Long Island that seals have
been found to occupy. These include sites as unusual as one in the shadow of
Kennedy Airport, and as remote as Fishers and Plum Islands. These surveys
are integral parts of CRESLI's Seal Research Program. Many students and
volunteers assist in these long term studies.
Site monitoring is conducted at one or more specific haul out sites.
Detailed observations are collected as part of a long term behavioral study
to better understand feeding, mating and social organization of seals. This
project includes recording the age and sex structure of a group of seals,
and the specific interactions of particular individuals based upon recurrent
observations of the displays and other interactions. CRESLI's Seal Research
Program will also include remote underwater acoustic monitoring of seal
vocalizations, which is a new area of study for seals worldwide. The seal
research program will also continue the telemetric studies begun in 1993 by
Samuel Sadove of CRESLI and Dr. Daryll Boness of the National Zoo, using
satellite tracking transmitters placed on seals. CRESLI is close to finally
unlocking the mysteries of seal movements in and out of the New York region.
Some
interesting facts about seals
Seals are able to hold their breath for a long time during dives, using
oxygen stored in the blood and muscles as well as the lungs.
Seals have a thick blubber layer which combined with a thick fur coat
protects them from the frigid climates in which they live.
Seal have large eyes which enable them to see quite well both above and
below the water.
Seals have a well developed sense of hearing and sensitive whiskers.
Their keen senses allow seals to be impressive predators.
Seals feed mainly on fish, crustaceans and shellfish. Some, such as the
leopard seal, feed on penguins, and the crabeater seal feeds almost exclusively
on tiny shrimp-like animals called krill
Observing Seals
Stay on the upper part of the beach or bluffs and away from the water's
edge. Remain quiet and calm during the observation.
Wear drab, muted colors.
Never throw objects at the animal or in the water.
If you encounter a seal on the beach stay at least 100 yards away from
the animal. It may well be healthy and just resting. Seals can deliver a nasty
bite and may carry diseases transmittable to humans and dogs.
If seals are spotted from a boat, maintain a distance of about 200
yards in order to avoid disrupting the animals' behavior.
If you find a seal (or other
marine mammal) that appears to be injured, entangled,
or otherwise in distress, do not approach it.
Call the NYS Marine Mammal and Sea Turtle Stranding Program
(631-369-9829) as soon as possible. Be ready to
provide the following information:
- Your name and phone number;
- The location of the animal
(exact or approximate);
- A description of the animal
and its apparent condition.
Long
Island's Seals
Although five species of seal can be found on Long Island's shores, only
the
harbor seal is common on Long Island. Anecdotal stories suggest
that harbor seals were quite abundant on Long Island up to the mid 1900's.
Grey seals used to be uncommon winter visitors, but now are
regularly seen in small numbers, with pups often stranding in March and
April. Until recently Arctic species such as
harp
and
hooded
seals rarely ventured south of northern Maine. Now more of these seals are
stranding on Long Island's beaches every year. In the 1994-5 season the
number of stranded harp seals actually exceeded harbor seals. In addition, a
small number of
ringed seals, another Arctic species, have stranded here.
In the early 1980's harbor seals were seen in small numbers mainly on
remote beaches and islands. Estimates of the total winter population were
thought to be several hundred with less than 15 strandings each year. In
following years more and more sightings were reported and strandings rose
dramatically, with well over 100 seals stranded each year. In 1995 there
were 157 strandings! The elimination of seal hunting in the continental US
and much of Canada may be a factor in the increase of seal populations.
Population increases north of Long Island may mean that these animals are
extending their range southward to Long Island.
CRESLI Seal Cruises
Join CRESLI on a naturalist guided exploration of Long Island's eastern
bays and remote outer islands to view these fascinating pinnipeds in
their natural habitat. Seals are often observed feeding, playing and
hauling out in the sun on their favorite rocks. Many species of seabirds
and ducks are also encountered, and LI's rich natural history is
discussed.
The cruises will begin boarding approximately 30 minutes prior to
leaving the dock. The cruise should take several hours.
Reservations must be made in advance via our seal cruise
reservation page (click
here).
What to bring? Warm clothing (dress in layers); warm, non-skid
shoes; hats; gloves; cameras; binoculars.
Click here for
Seal Cruise
information
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