Marine Mammal Strandings
Students learn how to assess a
stranded animal in mock-stranding
Stranding is defined in the dictionary as "leaving in a difficult situation."
This perfectly describes what happens when marine mammals, such as
dolphins and whales, come ashore. These animals are then at risk from
exposure to the wind and sun, which can dry out and damage the skin, as
well as cause the body to overheat. Larger animals are also subject to
respiratory distress because the body weight compresses the chest
cavity. Whenever a marine mammal is on the shore and out of the water,
there is a danger to that animal's very life.
of Stranding Networks
Marine mammals have been coming ashore for ages, but information about
the individual animals was taken only occasionally and without any
organization. In 1972, the United States passed the Marine Mammal
Protection Act, which protects all marine mammals in the wild (in U.S.
waters) and set up the first set of guidelines and regulations for
handling stranded animals.
From this Act, formal Stranding Networks were formed to oversee the
collection of data from the marine mammals that stranded. Data is taken
from animals that are dead or alive, and this data has served as an
invaluable tool in learning about the biology, illness, and mortality
of different species; not only the well-known (such as Tursiops) but
also the little known and even never before seen.
Most stranding networks are made up almost entirely of volunteers. For
those people who wish to help, there are numerous ways to get involved
with a network close to you. Experienced personnel are used to train
volunteers in the correct way to handle any marine mammal in distress.
In addition, these facilities have, in the past, been the areas where
live strandings have been rehabilitated. However, in recent years many
facilities are hesitant to bring in a sick or injured animal due to the
possibility of disease transmission to the healthy facility population.
Several facilities have been developed that only handle the stranded
animals and release or relocate these animals once they are again
There are many theories as to why marine mammals strand. Some of these
include disease, unusual environmental events (El Nino), intensive
fisheries operations, poisoning (both natural, such as algae toxins,
and man-made, such as pollution), and wandering out of normal range.
information that has been gathered since 1972 has allowed scientists to
more and more be able to diagnose a particular cause and then be able
to help an individual animal or population. Some species of animals,
such as pilot whales, will strand in large groups. It is sometimes
believed that they follow the lead animal to shore when that animal
becomes ill. Other animals, such as the harbor porpoise, are not very
social in the ocean and almost always strand as a single animal.
Approach & Action
A stranding team's course of action should a live marine mammal come
ashore depends upon the animal's size, age, health, available support,
environmental conditions, and time on the beach. The options are to tag
and release the animal if it is healthy, transport it to a facility for
medical attention, euthanize it, or let it die naturally. Decisions
should be made quickly and the action be swift to relieve the animal of
further injury and discomfort.
Once a stranded animal is located, its behavior should be observed and
a safe plan made before approaching the animal. When approaching the
stranding, go slowly, calmly and cautiously, avoiding loud or startling
sounds, abrupt movements, or bright lights. This will allow the animal
to gradually become accustomed to your presence. More than likely, it
will not be aggressive but could accidentally bite or hurt someone if
it thrashes around. If a mother and calf strand together, make sure to
always keep them close together.
The first observations to be made are behavioral. Strandings will fall into one of three categories:
- Alert (aware, responsive to stimulation)
- Weakly responsive (responsive only after much stimulation)
- Non-responsive (not responding to noise or touch)
Respirations on the animal can also help to determine condition.
Irregular and increased respiratory rates can indicate respiratory
fatigue and distress. Slower than normal respirations are also a
problem, and flushing water over the blowhole may stimulate breathing.
Heavy bleeding, frothy our foul-smelling fluids from the blowhole are
signs of critically poor health.
The next level of evaluation requires handling the animal and should be
done with caution. Gentle tapping near the eye should cause the animal
to blink. Any attempt to pry open the jaw, pull the tongue or tug the
flipper forward should be met with firm resistance. Once the jaw is
open, a finger pressed firmly on the gums over the teeth causes a
whitish color and should immediately return to a normal pink color-slow
return of color or bluish discoloration is a sign of poor circulation.
blood sample should be taken if possible. The results from this sample
would allow for evaluation of conditions that are not easily apparent
and for treatment if the animal is taken in for rehabilitation.
Measurements for scientific data should be taken while the animal is
Protect & Comfort
Volunteers can use the time between the stranding and the arrival of
the rescue team to help the animal be as comfortable as possible. This
will relieve distress and improve the animal's chance of recovery.
The eyes and blowhole must be protected from blowing sand and kept
moist with clean water. Pouring water around the blowhole area should
only be done when the blowhole is closed, usually best just after a
breath. It is easier to keep the areas clear if the animal is placed on
its belly. This is easily done with smaller animals. Holes can be dug
around the flippers and flukes to allow the stranding to lie in a
natural position. Placing sand or other safe materials next to the body
will keep it from rolling.
Sharp rocks, coral and seashells can have the same effect on marine
mammal skin as a knife. Remove any such objects, place padding around
the animal, or move the victim to a safer place. If the animal is
entangled in netting, line or debris, it should be removed carefully,
avoiding all risks to animal or human. Any skin that is damaged should
be kept moist, shaded and protected with zinc oxide or antibiotic
Students discuss the challenges of caring
for a stranded animal after having
transported Willy The Whale by stretcher
to a care facility.
Once a decision has been made as to release the animal to the ocean or
transport it to a facility for rehabilitation, moving the animal will
be required. This should only be done when supervised by trained
personnel and when enough manpower is available. Remember to have
enough people to safely carry the animal.
Most often the animal will be put into a stretcher especially designed
for marine mammals. These stretchers have specially designed holes for
the flippers. If the animal is going to be in the stretcher for more
than 20 minutes, the flippers should be through the openings to prevent
crushing and overheating. If the move is going to be short, many choose
to tuck the flippers next to the body and put the animal in the
stretcher backwards. This will keep the flippers from being damaged if
it is pulled onto a boat or other vehicle. Make sure that no seams or
creases are pressing into the skin.
an animal is released, it should be tagged if tags are available so
that it can be sighted or identified if it comes ashore again. Try to
release the animal in deeper water that is free of sandbanks or reefs.
Mothers and calves should be released together.
it is determined that the animal needs to be taken to a facility to be
rehabilitated, all decisions for treatment should be made by a
qualified veterinarian. Volunteer staff can still be helpful by
supplying manpower to follow the vet'' instructions. Many times the
care required will be intensive and most facilities appreciate the
help. The rehabilitation process can last a very long time, sometimes
Following these basic guidelines allows us to learn more about marine
mammal biology and can help not only an individual animal, but also an
entire population. The data obtained offers greater possibilities for
preventing future crises along our shorelines.
If you'd like further information on strandings, surf the topic on the Internet or check out the following web sites: