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
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
Grey seals, which are relatively abundant in our waters from late fall
until late spring. In recent years, "arctic" species such as
that were once extremely rare for Long Island, have also become more
Seal surveys can be conducted using land-based, aerial and shipboard platforms
concurrently (if possible) 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 field. Subsequently,
high resolution digital images taken from the
aircraft and vessels are viewed and counts are taken. 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 also now includesphoto-identification of harbor and grey seals using
high resolution digital SLR cameras connected to telescopes, These are
new areas of study for seals
on Long Island. Contributions to CRESLI from
seal walks and other activities have enabled us to purchase the necessary
equipment to conduct this new research. Thank you.
CRESLI's photo-identification catalog of harbor seals at
Dr. A. Kopelman has been compiling a catalog of harbor
seals that utilize the haul out site at Cupsogue beach (near
Moriches Inlet). As of February 2014, the catalog
contains 70 seals that are identifiable based upon pelage
marking patterns. Several of these seals have returned
every year, since 2006, other have returned less frequently
but stll return to use that site. The catalog is part of an
on-going long term study of site fidelity and population
dynamics. Samples photos from 60 identified and named seals
cab be seen at
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 and a
counter-current heat exchange system which combined with
fur,protects them from the loss of heat to the water and
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
Be a Responsible Seal Viewer
Comply with federal seal watching guidelines
HARASSMENT WARNING SIGNS:
If your presence causes any of the following
reactions, on land or in the water, you are too close.
Increased vocalizations by seals
Movement back into the water (single animal or
All eyes are on you (single animal or several in
Disturbance from normal resting position
(lifting their head to watch you)
STAY AT LEAST 50 YARDS AWAY FROM RESTING
Seals that are continually being approached
never get a chance to rest.
Repeated interaction can exhaust seals, leaving
them vulnerable to predation and illness
Continued disturbance of mother /pup pairs could
lead to abandonment and subsequent mortality of the
Stay on the upper part of the beach or bluffs and away from the water's
edge. Remain quiet and calm during the observation.
NEVER GET IN THE WATER WITH SEALS
Seals are large, wild animals and can be
If they feel threatened they may become
aggressive in order to defend themselves.
NEVER ATTEMPT TO FEED SEALS.
You could get seriously injured.
Feeding seals is against the law; you could be
arrested and/or fined.
Food that isn't a normal part of their diet will
do more harm than good!
Feeding negatively impedes their ability to hunt
and locate food on their own.
Feeding encourages seals to approach boats
looking for handouts.
This behavior has resulted in injuries from boat
LIMIT YOUR VIEWING TIME: TO A MAXIMUM OF 30
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
Your name and phone
The location of the
animal (exact or approximate);
A description of the
animal and its apparent condition.
Although five species of seal can be found on Long Island's shores, only
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
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 - charters for groups of 35 or
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. Send an e-mail requesting further
information about seal cruise group charters to
Dr. Arthur Kopelman