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Washington Department of Fish and Wildlife:
Marine Mammal Investigations Department Internship
WDFW/MMI Internship June 2011-Sept.2011
Robert Harvey
Western Washington University
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Table of Contents
Section One: Marine Mammals Worked With
Harbor Seal (Phoca Vitulina)…………………………………………………….……3
Gray Whale (Eschrichtius robustus)……………………………………………….….3
California Sea Lion (Zalophus californianus)……………………………………..…..3
Northern Sea Lion/Stellar Sea Lion (Eumetopias jubatus)…………………………....4
Guadalupe Fur Seal (Arctocephalus townsendi)……………………………….……...4
Harbor Porpoise (Phocoena phocoena)……………………………………………….4
Northern Elephant Seal (Mirounga angustirostris)……………………………………4
Northern Fur Seal (Callorhinus ursinus)………………………………………………4
Sea Otter (Enhydra lutris)……………………………………………………………...4
Section Two: Harbor Seal (Phoca vitulina) Necropsy Procedure
Introduction……………………………………………………………………………5
External Examination…………………………………………………………….......6-7
Internal Examination………………………………………………………...………7-11
Section Three: Gray Whale Necropsy………………………………………………………..12
Section Four: Captures……………………………………………………………..…...…13-14
Section Five: Major Study Sites………………………………………………………..….15-16
Section Six: Bibliography/ Resources……….………………………………………………..17
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Marine Mammals Worked With
Harbor Seal (Phoca vitulina):
Harbor seals come in variety of shades of color from white, to grey, to black and
everything in between. They generally have spotted coats with contrasting or matching colors to
their fur (Fig. 51). Males reach a maximum weight of 370 lbs. and can be 6'3" in length, with a
maximum life expectancy of 25 years. Females reach a maximum weight of 200 lbs., reaching
5'7" in length, with a maximum life expectancy on 35 years. Copulation of these animals usually
takes place in late December in shallow water, which brings about a significant amount of
fighting amongst the males. The gestation period last about 10 months (Sheffer & Slipp).
Females give birth to one pup a year, ranging from early spring to late summer, with the peak of
the pupping season being dependent on the specific geographical location.
In the Puget Sound, the major sites for haling out and giving birth include Woodard Bay,
Gertrude Island, and Eagle Island. The peak of the birthing season in the PS is mid-July, but
there are pups being born as late as early September each year. The pups remain with their
mothers for 4-6 weeks before they are abruptly weaned and abandoned. During this time the pup
is fully capable of doubling its initial birth weight due to the extremely high fat content in the
mother’s milk. The survival rate of pups in their first year is right around 50%. Factors that
contribute to their high death rate include abandonment from mothers, malnourishment,
predation (killer whales, dogs, and bear), infection from a wound, and detrimental human
interaction (Lambourn).
Harbor seals are very skittish animals, with the tendency to spook extremely easy. A hall
out of several hundred animals can all simultaneously panic and head into the water from just a
seagull flying overhead. Harbor seals can aggregate at hall outs in numbers up to 450 strong.
Hall outs include beaches, log booms, large rocks, and buoys. They prefer to hall out on beaches
that offer as much access to the water as possible, such as a spit. They prefer this type of
environment because it allows easy access to the water if they feel threatened, as they will not
venture more than a few yards from the waters’ edge.
Gray Whale (Eschrichtius robustus):
They grey whale is one of the more abundant whales in the Pacific Northwest. They have
a grey to dark grey color on their generally rough, barnacle crusted skin (Fig. 16). The barnacles
are the densest around the head of the animal, with whale lice being distributed all over the body.
They are characterized by their molted grey bodies, dorsal bumps, and upon diving have a
distinguishable raised fluke. Grey whales can grow upward of 49 feet, and weight over 80,000
lbs. They can live well over 40 years, as long as 75. They are a species of baleen whales, with
130-180 baleen plates in their mouth (Lambourn).
California Sea Lion (Zalophus californianus):
California sea lions are just one of the many species of sea lions. They are distinguishable
by their small ears, lighter colored flippers, and a narrow pronounced snout. Males are very
robust at the shoulders, chest, and neck, with a slender hind part. They have a very pronounced
forehead with an exaggerated sagital crest. They are capable of reaching up to 860 lbs., and
usually are a brown to light brown in color. Females are much smaller than males with slenderer
bodies. Their fur color is tan to yellow, and they can reach a max weight of 240 lbs. (Lambourn).
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Northern Sea Lion/Stellar Sea Lion (Eumetopias jubatus):
Stellar sea lions (or northern sea lion) are the largest of the eared seal family, with a
notable robust head and body. They have a short blunt and broad snout, contrary to the California
sea lion. They have broad, dark brown to black fore flippers with short and slim, lighter colored
hind flippers (Fig. 50). Males are often lighter in color than males. Males can reach a max weight
of 2,400 lbs. and be 11 feet long. Females can weigh up to 770 lbs. and reach 9'6" in length
(Lambourn).
Guadalupe Fur Seal (Arctocephalus townsendi):
Guadalupe fur seals are characterized by their narrow pointed snout, particularly males,
and their short, dark hind flippers. They have a uniformly dark fur, usually really thick around
male’s neck. Males can weigh up to 490 lbs. and reach 7'3" in length. Females weigh up to 121
lbs. and can reach 6'3" in length (Lambourn).
Harbor Porpoise (Phocoena phocoena):
These porpoises have the name that they do because they prefer the sanctuary of harbors
and inlets, as opposed to open waters. They are relatively difficult to spot, as they have a very
quick roll with little or no splashing when they surface to breath. Their backs are dark gray, with
lighter color on the sides and belly. They have small body, being one of the smaller porpoise
species, with a triangular dorsal fin at the top. Males reach a maximum weight around 134 lbs.
and a length of 5'2". Females reach a maximum weight of 168 lbs. and a length of 5'6"
(Lambourn).
Northern Elephant Seal (Mirounga angustirostris):
Elephant seals are characterized by the large inflatable air sack that sits on adult males
noses, primarily used to ward off potential threats on a males stretch of beach. These seals have a
very robust torso, which tapers down to narrow hips and short fore flippers. Males can weigh up
to 4,400 lbs. and reach 13'6" in length. Females are considerably smaller, reaching a maximum
weight of 1,300 lbs. and a length of 10' (Lambourn).
Northern Fur Seal (Callorhinus ursinus):
These fur seals are distinguishable by their small heads, short snouts, and blunt noses.
Their bodies are small and stocky, with relatively long hind flippers that have long digit tips.
Males develop massive chest and shoulders that act as extra protection in territorial disputes with
other males. Males reach a maximum weight of 600 lbs. and reach 6'11" in length. Females are
much smaller, weighing up to 132 lbs. and have a length of 4'11" (Lambourn).
Sea Otter (Enhydra lutris):
Sea otters are very large in size compared to other members of the otter family, as males
can weigh up to 100 lbs., and be over 4' in length. They have extremely dense fur, essential to
maintain their body temperature in cold water. They have short broad heads and short blunt
snouts. Sea otters spend a significant amount of their time floating and swimming on their backs,
where they feed and rest (Lambourn).
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Harbor Seal (Phoca vitulina) Necropsy Procedure
Necropsies are performed in order to gain further insight into the cause of death,
specifically with marine mammals. A properly performed necropsy creates a series of internal
and external observations that all contribute to reaching a diagnosis. By consistently performing
necropsies, trends in overall population health of a species can be monitored.
About one fourth of the 300 hours spend this summer working with Washington
Department of Fish and Wildlife in the Marine Mammal Investigations department was
dedicated to performing necropsies on dead pinnipeds ( which includes both eared, and earless
seals). The majority of the animals that necropsied were harbor seals (Phoca vitulina), as they
are the most abundant marine mammal in the Puget Sound. Due to their large numbers, there is a
constant flow of calls coming into the department during the summer months of animals
stranded, dead, or on the verge of death. Unfortunately there is a very high death rate amongst
pups during the summer months. I took part in roughly 25 different harbor seal necropsies over
the course of my internship.
There are several different ensuing investigations and sampling methods used to narrow
down the cause of death. These investigations are made from testing different samples of body
parts from the necropsied animal.
They include histopathology, which is “…the microscopic examination of tissue in order
to study the manifestations of disease” (Pugliares). Another is cytology, which are impression
smears that are taken from an open wound or any surface that are died and stained, and can be
examined on site. Virology is a common analysis performed, with samples most frequently being
taken from the lungs, serum, brain, liver, spleen, and lymph nodes. Sampling for microbiology
with sterile swabs is very common, as well as sampling for parasitology, which is the collection
of parasites from the animal. Sampling for toxins includes sampling for contaminants, which are
any toxins of or chemicals present in the marine environment that are potentially consumed by
marine mammals, thus integrated into their tissues (Pugliares). Samples for biotoxins are taken,
which are “naturally occurring toxins produced by dinoflagellates and other marine algae that
accumulate in animals as they are passed through the food web” (Pugliares). Finally, life history
and genetics are considered. Compilations of teeth, skin, stomach contents, reproductive organs,
and skeletons all can be used to determine, “age estimation, genetics, trophic position, habitat
usage, and reproductive status” (Pugliares).
Samples would be taken from all animals and sent to several different labs across the
country and in Canada. We would take a portion of each sample and place it them in formalin for
WDFW analysis and record keeping. The following is the process of a typical necropsy in
sequential order for a small pinniped.
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External Exam
Condition Code:
Prior to starting any necropsy, the carcass condition must be accessed to determine to
what extent sampling should be conducted on the animal. Ideally, necropsies are performed
within the first 48 hours of death but this is often not case. There is a five scaled system that
correlates to the condition of the animal. Code 1 means that the animal is still alive. Code 2 is a
fresh carcass, meaning the animal has been dead for roughly 24 hours. Code 3 is moderate
decomposition, which might include bloating, sloughing skin, and some scavenging. Code 4
implies advanced decomposition, meaning the skin is completely sloughing, there is a strong
odor, considerable scavenging, liquefied internal organs, and lose muscle around the bones. Code
5 includes mummification of just skeletal remains. A code 5 is relatively useless except for
extracting specific pieces of the skeleton (Pugliares).
Nutritional Condition:
The nutritional condition of a pinniped is dictated by looking at the pelvic and neck
region of the animal, creating 3 classes: robust, thin, and emaciated. A robust animal will have a
nice round shape, with no visible bone structure. In a thin animal, the pelvic and neck bones will
be slightly noticeable. An emaciated animal will have obvious protruding pelvic bones, visible
neck bones, and an outline of the rib cage as well. (Pugliares)
Most dead animals we encountered were in the thin to emaciated range, with the
exception of harbor seal pups. Dead pups were usually either very robust, appearing fat and
healthy, or very emaciated with little to no blubber. This always raised the question to what is
worse: a dead pup that was abandoned and extremely malnourished that never really had a
chance, or a healthy fat pup that had a lot of it mothers time and energy put into its success, yet it
still failed to make it?
Sex Determination
In order to determine the sex of a pinniped, the ventral surface of the animal must be
examined. Males will have a penile opening below the umbilical scar, with the penis bone being
visible through the skin in some cases. Females will have two horizontally spaced teats below the
umbilicus. You can also examine the perianal region of the animal, as males will only have an
anal opening, while females with have an anus and vagina.
Integument Observation
A further external inspection of the animal should include a description of the eyes, ears,
mouth, nostrils, genital area, umbilicus (mainly for pups), anus, fur, and skin (Fig.4). Any
abnormalities seen should be noted and possibly examined further. Open wounds or abrasions
are noted, as well as any fungal disease or obvious external parasite or infection.
Skin and Teeth Sampling
A portion of skin is removed between the digits of the left rear flipper. The upper left and
right canine tooth is also removed. The teeth serve as vital clues to determine the age of the
animal, as well as possible infection of the mouth.
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Skin and Blubber Removal
With the animal ventral side up, an incision is made under the jaw that runs parallel down
the animal to the anus. Perpendicular cuts are then made off the main incision a few inches apart
down the length of the animal, creating a series of panels. The blubber is then removed with the
skin in each panel, exposing muscle and the internal body cavity. During this process it is
important to look for any bruising, parasites, or signs of hemorrhaging. Samples of blubber are
almost always taken.
Skeletal Muscle Removal
After the blubber has been removed, the exposed muscle should be examined closely for
any signs of hemorrhaging or bruising. The color and texture of the muscle is examined, as well
as any signs of disproportion of muscle mass. Muscle is usually taken for samples, and in doing
this I learned the hard way it is important not to cut open the internal body cavity until muscle
has been removed.
Internal Examination
Scapula and Prescapular Lymph Node
With the animal still ventral side up, cut away the connective tissue holding the front
flippers and scapula to the body wall. You locate the prescapular lymph node, which should be
somewhere between the scapula and body on the cranial side of the bone (Pugliares). A normal
lymph node should appear round or oval shaped, have a firm consistent texture, and be light
brown to purple in color. Any abnormality in the size, shape, color, or texture of the lymph node
should be noted, which is usually correlative to a reaction. (Fig. 10)
Thyroid
The thyroids are located on either side of the trachea of the animal. They usually appear
dark purple, have flat circular shape, and have a texture resembling that of smooth muscle. They
usually are taken for sampling.
Thymus
Found most commonly in neonates (up to 4 weeks old) and juveniles, the thymus is large
lymphoid organ. This organ is unique, in that as time passes, it is absorbed after weaning and is
not usually found in adult pinnipeds (Pugliares). Its primary function is to produce T-cells, which
is critical in development of immune cells during early development with pups.
Opening the Rib Cage
To open the thoracic cavity and rib cage, trim away any connective muscle attached to
the rib cage. Starting with the top rib, find the cartilaginous “sweet spot” (Pugliares) in the
middle of the ribs. This flexible spot is what allows for deep inhalation and exhalation. Continue
to open and spread the rib cage until the entire thoracic cavity is open, exposing all of the
internal organs. Note for any obvious abnormalities such as discolorations, excess fluid
accumulation, or lesions. (Figs. 5, 6)
Lungs
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The lungs occupy the most space within the thoracic cavity, with tissue that’s usually
bright to dark pink in color with a spongy texture. To detach the lungs, severe their connection to
the trachea, then remove from the cavity (Fig. 7). Normal lungs should be relatively firm and air
filled, which can be tested by applying pressure with a finger and seeing if they bounce back, or
placing in formalin and seeing if they float. To internally examine, begin with an incision in the
trachea and work your away posterior into the bronchioles of each lung (Pugliares). Look for and
note any present parasites, froth, or fluids. Emphysema is common in dead animals.
Trachea
The trachea is a long, flexible, tubular organ connected to the lungs. Cut open the trachea
slowly with scissors all to the apex of the throat. Look for mucus build up, froth, blood, or any
abnormal discoloration.
Heart Muscle and Valves
Prior to removing the heart, note any abnormality in size, color, and texture of the right
and left atria and ventricles, aorta, and pulmonary valves. Remove the heart by cutting
transversely across the aorta and pulmonary artery, making sure to leave ~5.0 cm of each vessel
attached to the heart muscle (Lambourn). To open the heart, take scissors and “…make a small
opening in the right atrium and cut down along the peripheral edge of the right ventricle to the
down the apex. Continue cutting along the right ventricle side of the septum until this chamber
joins the pulmonary artery and cut up through this vessel. Next, snip the left ventricle side of the
apex cut through the muscle along the septum, and continue through the aorta” (Pugliares). This
will result in the heart being fully open and intact. Inspect each chamber carefully for any worms
or other foreign material. The left ventricle should be considerably thicker than the right.
Diaphragm
The diaphragm is a thin, dark colored, smooth muscle attached to the rib cage. It
separates the thoracic and abdominal cavities. Look for any tears or adhesions to the diaphragm,
and note any unusual texture or color found throughout it. Trim away the diaphragm enough to
have access to the abdominal organs.
Liver
The liver should be found lying across the stomach, and should occupy a significant
amount of space in the abdominal cavity. It is usually purple in color and “multi-lobular”
(Pugliares). Note any color patterns or blotches of color, as well as any variation in texture
throughout. Take a thin slice of the liver from the midsection and note any abnormalities in the
cross section. (Fig. 9)
Gall Bladder
The gall bladder can be found tucked between the livers lobes. It is dark green to
green/brown in color, fairly thick walled, and round. Bile is almost always collected here to
check for contaminants by a sterile syringe and needle, and upon removal it can be opened up
further for examination. Waiting to remove the gall bladder before opening it up is important
because it stops other organs from being contaminated by bile once it is opened. Check for and
note any small stones or parasites found (Lambourn).
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Spleen
The spleen is mottled purple to white, flat, thin organ located underneath the stomach
against the left side of the body. It is common for pinnipeds to have uneven jagged spleens.
Remove the spleen, and on both the surface and interior of the spleen, note shape, size, color, and
texture. (Fig. 9)
Pancreas
The pancreas is usually peach colored, inconsistently shaped, relatively soft and attached
to the mesentery and rest along the small intestines (Pugliares). Remove it from the cavity by
detaching it from the mesenteric tissue. Note the size, shape, color, and texture of the surface.
Then cut a cross section and look for any changes in color or texture.
Mesentery and Mesenteric lymph node
The mesentery is an extremely thin connective tissue band that is attached to the
intestines. This tissue should be translucent and be difficult to initially cut, as it should be pretty
tough to tear. Examine the mesentery for any abnormal adhesions, thickening in places, or any
noticeably thin portions. The mesenteric lymph node is a banana shaped, dark tan to gray
colored, lymph node that is suspended in place by the mesentery. Cut the mesenteric lymph node
out of the mesentery and examine the interior and exterior for any changes in color or texture
(Lambourn).
Adrenal Glands
The left and right adrenal glands are located anterior to the base of the kidneys, attached
to the abdominal wall. They are small, oblong, light purple, with irregular grooves covering the
surface. Always remove the adrenals before the kidney, because the kidney serves as an
important reference point. Remove the adrenals by severing the connective tissue holding them
to the body wall. Examine the exterior, then slice in half and note the inside of them. The cross
section should show a dark center, gradually getting lighter outward. Note abnormal sized
adrenals always (Pugliares).
Kidneys
The left and right kidneys purple to maroon in color, egg shaped, covered in cluster of
“reniculi” (miniature kidneys) and are attached to the dorsal abdominal wall” (Pugliares). There
is a thin capsule surrounding the kidneys, examine this for any fluids or abnormal bumps, noting
its color and thickness. Cut the kidney out, observing the size, shape, color, and texture of each
kidney individually. Cut a cross section and examine the inside of each kidney. Look for any
difference in the size of the two kidneys. (Fig. 8)
Urinary Bladder
The urinary bladder is relatively small, light red to light pink in color, located anterior to
the pelvic bone against the ventral body wall (Pugliares). It is usually thick walled, but if it is
enlarged with urine it is thin walled and can be semi-translucent. Before the bladder is removed,
a sterile syringe and needle is used to extract urine. With extracted urine, we would routinely
perform ‘in house’ domoic acid test. After urine extraction, remove the bladder and examine it
internally by cutting along the length of the organ. Note the color and texture of the inside, and
look for any signs on infection.
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Female-Ovaries and Uterus
The uterus and ovaries can be recognized by tracing the reproductive tract starting at the
vagina, working your way to the uterus where it splits to the left and right, with both ends ending
at the ovaries (Pugliares). The uterus is usually tan in color with varying size and thickness,
which is correlated to the sexual maturity and size of the animal. The size of the uterus is also an
indicator of the animal’s sexual history. Note the size, shape, and color of the uterus. If a fetus is
present and is too small or an individual necropsy, open up the abdomen and collect sterile swabs
and preserve the fetus in formalin.
The ovaries are attached to the end of each uterine horn, usually a grey to yellow white in
color. Detach the ovaries from the uterus and exam the external side, noting its size, shape, and
color. A mature animal’s ovary will have random, dark scars, indicating it has had previous
ovulations. A pregnant female will have a large yellow mass attached to the ovary. Examine each
ovary individually, counting its scars and compare the size of the two (Lambourn).
Male-Testes
The testes are spindled shaped, light gray to tan in color, and located outside of the
abdominal cavity, along the ventral wall next to the hip bones. Remove the testis, taking
measurements of both, noting any difference in size, color, or texture between the two. Cut at
least one open and examine internally as well.
Stomach
Prior to removing the stomach, both ends need to be tied off with zip ties. This is done in
order to so no material inside is lost during the extraction process. Once tied off, remove the
stomach and examine the exterior for and significant discolorations or lacerations. Weight the
stomach while it is still tied off, then open the stomach and empty its contents into sieves. Note
the composition of the stomach contents including, fish bones, fully or partially digested food,
rocks, seaweed, parasites, shells, or any foreign trash. If any foreign objects are found,
photograph and document it under human interaction. Once the stomach is empty, examine the
lining of it, noting the color and texture of the internal folding, look for any ulcers, parasites, or
discoloration. Finally, weight the stomach when it is empty.
Esophagus
Follow the esophagus from the posterior end to the mouth. Open by making slow cuts
with scissors, starting posterior. Note the internal lining, looking for any froth, abnormal texture
or color, and any other contents.
Small Intestines
The intestines are always done toward the end of the necropsy in order not to contaminate
other organs with its insides. Look for areas of hemorrhaging or any parasites of the surface. The
inside is usually not examined, but in the case it was we would randomly spot check it by
making 5-10 random incisions, evenly spaced (Lambourn). Any abnormalities should be noted.
(Fig. 9)
Large Intestines
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The large intestines is examined in the exact manner as the small intestines, and in many
cases the time was not taken distinguish between the two.
Colon
Examine the surface for any areas of discoloration. Opening the posterior end of the
colon, place a whirl pack bag on the open end and squeeze out any feces remaining in the animal.
Note color and texture of the feces.
Removal and Examination of the Brain
The brain is the most delicate and easily disrupted organ the body, so extreme care must
be taken in the removal process. It took me two botched attempts, resulting in mangled brain
samples until I was able to master the technique.
The head must first be detached from the body. Once it is remove all of the excess skin,
fat, and muscle from the back of the skull. Using a bone saw make two parallel cuts along the
sides of the skull starting at the back and working forward till the sagittal crest. Then make a
perpendicular cut along the crest, intersecting the two prior cuts at their ends. This should result
in a squared off U shape. It is important to fully penetrate the bone without penetrating the brain.
Slowly pry open the back of the top of the skull upward, exposing the brain. Slide your finger
along the base of the now open skull, severing any small connections still held on the side of the
skull. If done correctly, it should pop off with no damage inflicted to the brain. Note the external
surface of the brain for color, texture, any parasites, or lesions (Fig 11).
In the case sterile brain samples were requested for a specific animal, extra steps were
taken in removal. Prior to opening the skull, a torch is lit to sterilize a clean scalpel for removing
a top piece of brain that is immediately placed in cultured falcon tube. Once the brain is exposed,
the scalpel and base of the falcon tube are heated, and the brain sample it immediately placed
inside and sealed off.
Skull Cleaning
Many of the heads taken off the seals were flensed down to remove as much muscle,
skin, and blubber as possible. They would then be placed in mesh bags and boiled in a bleach
solution, until the remaining scraps had fallen off completely or were cooked enough to be cut
off (Fig. 12). The skulls and sets of teeth were sent off to different laboratories, and a good
number of them stayed with WDFW for record keeping.
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Gray Whale Necropsy
On July 27, 2011 a Gray whale (Eschrichtius robustus) was alive and stranded at Erlands
Point in Bremerton, WA. It was a juvenile male, 3 to 5 years in age, 30 feet long, and an
estimated 25,000lbs (Fig 16). The animal was beached on an outgoing tide, apparently too weak
to swim out with it. WDFW responded and monitored the animal, doing our best to keep it alive.
Unfortunately the animal remained beach, and since the massive animal was no longer buoyant
in the water, it suffocated under its own weight.
We arrived on site the next morning on July 28, around 7 AM to begin the necropsy
procedure. The animal was lying on its ventral side in several feet of water in the outgoing tide.
With 15 individuals we tried to roll the animal on its side for easier access to its organs, but to
avail. It was decided the necropsy would be performed with the whale on its stomach. The
animal was covered in lacerations and sea lice, with a substantial amount of barnacles located
around the head (Fig. 52).
The process began with flensing away sections of blubber on the whale’s side. Being
such a malnourished and small gray whale, its blubber depth was relatively shallow (Figs. 18,
20). Once opened, the necropsy process for the most part follows that of a pinniped (i.e. harbor
seal) necropsy. Several samples were taken of all body parts (Fig. 22) including, blubber, skin,
baleen plates, muscle, brain, kidneys (Figs. 26, 27), testes, lungs, intestines, pancreas, spleen,
liver, lungs, and heart. These samples are highly desired, as fresh whale samples are not that
common. Samples were sent to labs across the country, to Canada, and kept for WDFW records.
The initial cause of death was assumed to be from malnourishment. The whale was
extremely thin for its length, leading us to conlclude it had beached itself in shallow water and
lacked the strength necessary to swim off. It will be several months before the reports come back
to WDFW as to what other problems the animal was experiencing internally.
The carcass disposal process was taken care of by a local Native American tribe, who
voluntarily towed the whale away at an ensuing high tide.
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Captures
WDFW conducts several large scale harbor Seal (Phoca vitulina) captures annually in the
south Puget Sound area. The main purpose of this is to monitor the population for diseases,
evaluate individual and overall health, and to track individual animals. Working with NOAA,
Cascadia Research Collective, veterinarians from around the state and assisted by the McNeil
Island Fire Department, mass captures are conducted on Gertrude Island every September during
several different days.
September is chosen because the animals are usually done giving birth, and are in a
relaxed recuperation state. The capture site is at the end of a long spit, surrounded by 270º of
water, where the animals are located (Fig. 29). The process is very rehearsed and tactical, as
hauling in up to 40 harbor seals at once is quite the task.
A 300 foot long, twelve foot wide, lead lined bottom, buoyed topped net is used to
capture the animals. There are three boats involved in the process of throwing the net, each with
its own responsibility (Fig 30). The lead boat holds the pre stacked net, the hook boat follows,
and the ‘scare’ boat makes up the rear. The lead boat accelerates in a slingshot manner around
the spit, throwing one of the buoyed ends at the starting place of where the animals are hauled
out.
The hook boat follows, hooking the end of the thrown net with a gaff and pulling it to
shore, while the lead boat hooks around the end of the spit. During this process, my position was
front man on the hook boat. It was my job to gaff the end of the net thrown, jump off the boat
and run it to shore.
The scare boat stays in the water at the center of the net, revving the engine, yelling, and
slapping the water with paddles to scare the animals. This commotion is aimed at panicking the
animals back toward shore and stopping as many as possible from slipping under the net. The
lead and hook boats are at this point both on shore, and with several individuals at each end, they
begin pulling in the net. The net is pulled to the sides of the beach, concentrating the animals
toward the middle.
Being my second year participating in captures and being comfortable with handling
seals, I was assigned one of the three positions of pulling the animals one by one out of the net.
We would target the pups and smaller females first, followed the larger adults. This part in the
process is considered the most dangerous; being that an angry harbor seal can inflict significant
damage to a person if given the chance. Pulling the seals by their hind flippers, we drag them up
the beach and throw a “hoop net” over individual animals to secure them (Fig.33). Spacing the
animals apart so they are not fighting amongst themselves, the beach is at this point littered with
about 25 captured seals (Fig 31). One individual is assigned the job of checking on each animal
periodically and cooling them with seawater.
A portable weight station is set up (Fig. 34), along with two tagging/ branding areas, a
portable stove to head the branding irons, and a and tagging prep. station (Fig. 35). After being
weighed, sexed, and measured, my job was to move individual animals from hoop nets to the
tagging/ branding station and restrain them during the process (Fig. 36). To minimize stress on
the animals we always point their head in the direction of the water and lay a wet cloth over their
eyes (Fig. 38). I would then straddle the animals, pinching them with my knees and holding the
top of the head, all while trying to use the least amount of necessary force. Occasionally, there
are seals weighing in the order of 200 lbs. that require several people to hold down. I learned this
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the hard way when I rode a large adult male several yards down the beach before help came to
restrain him (Fig. 44).
Once controlled, blood is drawn from each animal which goes into the centrifuge back at
the lab to obtain serum. The blood is also used to check for different diseases. Blubber, fur, and
whisker samples are also taken at this time (Fig. 40). Each animal is then assigned a combination
of color coded ribbons that are tagged to their hind flippers, which are recognizable for re-sight
and tracking purpose (Fig. 42). Each animal is then assigned a specific 3 digit number for adults,
or a 2 digit number for healthy pups. A scuba tank of compressed air is used to completely dry
fur prior to branding. The branding process does not hurt the animals, as it just chars the fur,
never getting close to their blubber or bare skin (Fig. 43). A few pups we catch that are in good
health are not branded, and have a satellite tracking devices adhered to their backs. The devices
do not hurt the animal and usually fall off with the seals first full molt.
When each animal has been fully processed through, the eye cover is removed, and the
animal is released. For the most part they head straight for the water; however the occasional
irritated animal will turn around and snap at you. These individuals usually just require a gentle
nudge in the rear.
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Major Study Sites
Gertrude Island
One of my favorite jobs was observing and studying beached seals at several of the major
Puget Sound hall outs. The purpose of these observation periods was to collect as many re-sights
of branded and tagged animals, get a pup count, get a total head count, look for injured or sickly
animals, and to monitor behavior. Everything seen or heard is meticulously written down and
transferred to the WDFW data base. All of this information summed up results in a relatively
accurate representation of the animals migration around the Sound, their overall health, total
numbers, and pup mortality rate.
The major study site and the breeding ground for harbor seals (Phoca vitulina) in the
Puget Sound are on Gertrude Island. Gertrude is a 10 acre island, located within Still Harbor on
the northwest side of McNeil Island. The south end of Gertrude Serves as the major hall out area,
as it offers a ~300ft long, east curving sand spit with 15-25° slopes of both sides (Fig 45)
(Babson & Skidmore). The spit serves as perfect resting, mating, birthing site for seals, due to its
270° encirclement of water, allowing for quick escape if they feel threatened. Gertrude serves as
an ideal study site because it falls within the parameters of the former McNeil Island
Penitentiary, and the currently operating Special Corrections Facility.
There is a 100 yard security limit that circles McNeil, including Gertrude (Fig. 46). This
allows wildlife to exist almost completely undisturbed, as I encountered raccoons, bald eagles,
and deer on every single outing that had little fear of humans. I was fortunate enough to be
cleared to visit the island via ferry as a WDFW intern, and once on McNeil we had a state truck
used to get to where we needed to go. There were two methods for observations: pack a bag for
the day and cross the low tide land bridge (Fig. 47), or sit in one of our two blinds with a spotting
scope and study the seals from a distance (Figs. 48, 49). These surveys were conducted several
times a week at Gertrude across the summer months, with all of the counts and re-sights being
cataloged for study.
Woodard Bay
Woodard Bay is located in South Puget Sound, branching off to the south west of
Henderson Inlet. The bay was a former area for major log transport out of the south sound, which
shut down operations in the mid-1980s (Lambourn). Left behind were a series of log booms that
quickly developed into a major harbor seal (Phoca vitulina) hall out area. This is an ideal hall out
in that it offers a 360° encasement of water, allowing for easy escape for the seals in threatened.
Being that I lived 5 minutes away, I frequented Woodard with a spotting scope. Several
times a week I recorded and re-sights, pup counts, etc. What I observed were an increasing
number of animals leading up to the peak of pupping season, followed by a drastic decline in
consistent numbers of hauled out animals. The reason for this local immigration, followed by
emigration is centered on females hauling out just to give birth. Once birth has taken place, the
animals would remain in the area for a while, giving the pup the opportunity to fatten up and for
the mother to regain its weight. During this period the mother provides massive amounts of milk
to the pup, and therefore must constantly be in search of food.
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Following the pupping season, the majority to the seals leave Woodard Bay as their
major hall out, but there are still animals present year round in this area.
Eagle Island
Eagle Island is a small island located in the South Sound, north of Anderson Island and
south of McNeil Island. It once was a major harbor seal haul out (Phoca vitulina) in the Puget
Sound, but after it was declared a state park, the numbers of animals that frequent the island has
significantly decreased (Lambourn). Constant human visitors to the island contributed mostly to
this, as well as increased noise and boat traffic in the area.
Still, up to 100 animals can at times be seen hauled out on the northeast corner of the
island. Counts can be taken from the south shore of McNeil island, but to get re-sights we would
approach with a small boat to get as close as possible.
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Bibliography
Babson, John W., Skidmore, James. “A Conservation Plan for a Colony of Harbor Seals (Phoca
vitulina) Gertrude Island, WA.” Washington Department of Game (1981)
Lambourn, Dyanna. Personal Interviews. June 23-September 12 2011
Pugliares, Katie R., Bogomolni, Andrea., Touhey, Kathleen M., Herzig, Sarah M., Harry,
Charles T., Moore J. Michael. 2007 Sept. “Marine Mammal Necropsy: An introduction
guide for stranding responders and field biologist”. Buzzards Bay, MA., Woods Hole,
MA: Woods Hole Oceanographic Institution. National Oceanic and Atmospheric
Administration. WHOI-2007-06: 29-52
Scheffer, T.H., Slipp, J.W. “The Harbor Seal in Washington State.” Am. Midl. Nature
32 (1944): 373-416