Detailed Clinical and Pathological Characteristics
|
General |
- Oil causes the barbules of feathers to stick together. (J30.51.w1)
- Oiled birds lose waterproofing, insulation and buoyancy and have reduced
ability to fly, swim, dive, feed or escape. There are also the toxic effects of ingested
oil (encountered when preening, drinking contaminated water or eating contaminated food)
and the effect on embryos of oil contamination of egg shells.
- Ingested oil also acts as a
non-specific stressor and increases susceptibility to infectious
diseases.
- Oil may have
long-term effects on reproduction. (B334.w3)
- Oiling may have effects on annual cycles such as moulting and nesting
dates. (B334.w3)
(B15,
B18, B20.13.w10, B36.42.w42,
B334.w3, J30.51.w1, P9.1.w3, P4.1990.w1,
D32) |
Clinical
Characteristics
|
BIRDS |
Oiled birds have reduced water repellency of feathers and reduced
insulation. Their metabolic rate and food requirements increase; at the
same time oiled birds tend to spend large amounts of time not foraging but
attempting to preen the feathers. Affected birds become starved and
emaciated, hypothermic, and stresses, in addition to which are the toxic
effects of ingested oil. (P3.1961-1970.w1)
Birds which are found on the shore and brought in for rehabilitation
are generally in poor condition. (P3.1961-1970.w1)
General and Plumage:
- Birds may appear wet and chilled. (B20.13.w10)
- Oiled birds out on the water may be seen splashing a lot due to
flapping their wings in attempts to stay floating on the surface. (D160.App4.w12)
- Affected animals may be beached or perched, being forced to leave
the water because they are chilled (to reduce heat loss). (B20.13.w10,
B36.42.w42, J318.24.w1)
- Oiled birds tend to leave the water and preen "incessantly".
(J320.8.w1)
- Note: Birds stranded on shore, and perhaps weak, are at
increased risk of predation. (J318.24.w1)
- Oiled birds have reduced buoyancy; birds still in the water may be noted to float lower
in the water than normal. (B36.42.w42,
J320.8.w1)
- It may be possible to smell oil contamination on the affected
casualty. (B20.13.w10)
- Oil may be visible on the feathers; particularly on individuals in which the plumage is normally pale in
colour the individual may appear discoloured, dirty or unkempt. This
is particularly obvious if the petroleum product involves is dark in
colour. (B20.13.w10,
B36.42.w42)
- With light oiling, there may be a thin film of
oil on the feathers. (J30.51.w1)
- With heavy oiling both the buoyancy and mobility of the affected
bird may be visibly affected. (J30.51.w1,
J320.8.w1,
P62.14.w1)
- Heavily oiled birds may struggle to swim and find it impossible
to fly. (B284.18.w18,
J320.8.w1)
- In Anas
platyrhynchos - Mallard experimentally oiled by
being placed onto water to which oil had been added, thermal
conductance increased, indicating reduced insulation from the
plumage. With higher levels of oiling, the resting heat production
increased by about 37.5%, from about 80 to 110 kcal/kg/day, and
the lower critical temperature shifted from about 12 °C to about
25 °C. Oiling of scaup (Aythya - (Genus);
Aythya marila or Aythya affinis not specified)
showed similar changes in resting heat production and a similar
shift in lower critical temperature. The increase in thermal
conductance, i.e. decrease in insulation, in the scaup was greater
than that of the mallard: about 50% high for the heavily oiled
scaup. Oiled scaup "may survive in oily water for a
relatively short time." (J30.51.w1)
- The external appearance may vary depending on the type of oil
involved: in a spill involving a fish oil mixture, penguins were
observed to be covered with a sticky, white, foul-smelling coat of
oil, and were shivering. (N15.62.w1)
In addition to the effects on the plumage other signs may include:
- Lethargy. (B20.13.w10)
- Dermatitis. (B20.13.w10)
- Skin may be reddened. (P4.1990.w1)
- Conjunctivitis. (B284.18.w18)
- Corneal ulcers (B284.18.w18,
P4.1990.w1)
- These may be caused by the irritant effects of oil
and/or from sand irritation in birds becoming beached on sandy shores.
(P4.1990.w1)
- Respiratory distress. (B20.13.w10)
- Dehydration: eyes appear oval and sunken, skin is tight and
inelastic, PCV
may be over 60%. (B11.35.w3)
- Loss of weight and body condition, malnutrition. (B20.13.w10)
- Thermoregulatory disturbance: (B20.13.w10)
- Anaemia (pale mucous membranes) due to toxic effects of some
petroleum oils; PCV may be below 30%. (B11.35.w3)
- Diarrhoea due to gastrointestinal irritation from ingested oil.
(B11.35.w3)
- Neurological abnormalities such as disorientation and coma. (B20.13.w10)
- Oiled individuals may be easier to catch than their non-oiled
counterparts. (B20.13.w10)
- NOTE: Many clinical signs and findings may be related to
stress, dehydration, hypothermia (See: Chilling - Hypothermia)
and starvation (See: Starvation in Waterfowl and Seabirds (with notes on hedgehogs)).
(B20.13.w10, D183.w3)
- A small amount of oiling may reduce insulation and
water-repellency, leading to increased heat loss, shivering
and, if adequate food is not available, use of body reserves.
This decreases the bird's average density, leading to reduced
dive length and depth, making it more difficult for diving
birds to get food, leading to increased use of energy reserves
and a "spiral" leading to death from exposure and
starvation. (J313.11.w2)
- Dehydration may occur due to decreased consumption of food, increased
metabolic demands, loss of fluids from diarrhoea and decreased fluid
absorption due to gastro-intestinal tract irritation by oil. (D183.w3)
Experimental data:
- Nestling Larus argentatus - Herring gull
and Fratercula arctica - Atlantic puffin,
dosed with Prudhoe Bay crude oil at 10 or 20 mg/kg bodyweight orally,
ate less than controls and those given lower doses of oil, and lost
weight. The gulls passed oil in their droppings within 10 minutes of
being given the oil. Some birds became weak on the fourth or fifth
days of being given the oil, including two gulls which were moribund
on the fifth day and one puffin which was weak on day four and died
during the night. (J26.23.w1)
- Body mass and body temperature, as well as water flux, plasma sodium
and chloride, and food intake, significantly decreased in Larus glaucescens -
Glaucous-winged
gulls (Larus
(Genus)) experimentally oiled with about 150 ml
of Marine Bunker fuel (approximately No. 6 grade), despite their being
fed and given free access to fresh drinking water. (J30.68.w1)
Clinical pathology:
- NOTE: It is important to recognise that findings may be
related not only specifically to toxic effects of oiling but to
oil-related stress and, in birds which have been caught and brought
into care, stress related to capture, handling etc. (B20.13.w10, D183.w3,
J4.187.w1)
- Larus argentatus - Herring
gull adults brought into captivity, housed outside in
individual cages within sight and sound of conspecifics, and which
showed apparent behavioural adaptation (no apparent behavioural
signs of stress after three days in captivity), showed marked and
significant (P <0.05) leucocytosis, heterophilia and anaemia,
which developed by as early as four days of captivity and did not
return to base-line values by 28 days; the leucocytosis was due to
the heterophilia; total and differential leucocyte
counts varied
widely between individuals and between days in a given individual.
PCV was lowest at day 12 and remained at this level to day 20 then
began to rise, but had not returned to base-line by 28 days. (J4.187.w1)
- Haemolytic anaemia was noted in a number of Uria aalge - Common murre
oiled with Bunker C or Bunker C mixed with other oils, with an
average haematocrit of 37.7%, indicating a 25 to 30% reduction in red
blood cells, but with considerable variation, some birds having a loss
of more than 80% of their red blood cells, with a PCV of under 10%.
Recovery from this anaemia was noted to be slow. (J311.10.w2)
- Severe haemolytic anaemia with Heinz-body formation was noted in
nestling Larus argentatus - Herring gull
and Fratercula arctica - Atlantic puffin
following experimental administration of Prudhoe Bay crude oil at 10 or
20 mg/kg bodyweight orally. PCV and
haemoglobin levels were
significantly (P<0.05) reduced in these birds, while the percentage
of reticulocytes and the percentage of cells containing Heinz-bodies
were significantly increased. In gulls dosed with 4 ml/kg bodyweight,
the only significant change was a decrease in PCV (P <0.05); with 1
ml/kg there were no measured effects. (J22.220.w1)
- Abnormalities noted in blood smears from nestling Larus argentatus - Herring gull
and Fratercula arctica - Atlantic puffin,
following experimental administration of Prudhoe Bay crude oil at 10
mg/kg bodyweight orally, included anisocytosis, poikilocytosis,
reticulocytosis and formation of Heinz bodies. Transmission electron
micrographs revealed both intracytoplasmic and intranuclear Heinz
bodies, various abnormal cytoplasmic vesicles, degenerate
mitochondria, lack of circumferential microtubules, abnormal shape
and crenulation of the plasma membrane of the cells. Injecting gulls
with phenylhydrazine (a known oxidant) resulted in similar lesions,
while gulls made anaemic by haemorrhage showed reticulocytosis but
not the other abnormalities. The findings further supported the
hypothesis that the toxicity of the oil was due to oxidant
chemicals. (J26.22.w1)
- Increased percentage heterophils and decreased percentage lymphocytes
were found on day five in nestling Larus argentatus - Herring gull
and Fratercula arctica - Atlantic puffin,
following experimental administration of Prudhoe Bay crude oil at 10
mg/kg bodyweight orally. (J26.22.w1)
- In Larus glaucescens - Glaucous-winged
gulls (Larus
(Genus)) experimentally oiled with about 150 ml
of Marine Bunker fuel (approximately No. 6 grade) and left oiled for
four to five days, plasma sodium and plasma chloride decreased.
(J30.68.w1)
- Hyperproteinaemia (5.0-8.0 g/dL) at about 1-2 weeks after oiling has
been described in Uria aalge - Common murre and found to be associated with an
increase in acute phase proteins. (P4.1990.w1)
WATERFOWL
- Oil may be grossly visible from a distance, particularly on pale-coloured
birds. Feathers may be matted with oil and it may be possible to smell the oil. Oil may be
found around the vent (cloaca). Eyes and nares may be matted with oil. The whole bird may
be covered with oil, or only certain areas.
- Birds may float lower in the water than usual due to loss of buoyancy,
and may leave the water for any available islands, rocks etc.
- Lethargy, dermatitis, conjunctivitis, respiratory distress may be noted,
also disorientation and coma.
- Often anorexic, even if food available.
- Loss of condition may be noted (prominent breastbone) and can be severe
after only 48 hours.
- Diarrhoea may occur due to gastrointestinal irritation from ingested oil.
- Dehydration (sunken eyes, tight inelastic skin, packed cell volume over
60%) may result from diarrhoea.
- Hypothermia is common.
- Corneal irritation and ulceration may be seen.
- Deaths may occur due to hypothermia (see: Chilling/Hypothermia), Starvation, Drowning, or
combinations of these.
- Eggs (contaminated with oil from plumage of adult) may fail to hatch.
- Ducks experimentally dosed with high doses of certain petroleum oils
(diesel and a cutting oil) showed ataxia, incoordination, tremors and
pupillary constriction. The oils contained organic phosphates, and
cholinesterase inhibition was suspected. (J40.30.w2)
Clinical pathology:
- Anaemia is common and may be severe: packed cell volume below 10% may be
recorded. N.B. the PCV of a
dehydrated bird may appear normal, despite
anaemia. Low total proteins (total solids) is also common (0.3-1.9g/dl may be seen).
- Haemolytic anaemia was found in wild seaducks (Melanitta fusca - White-winged scoter,
Melanitta nigra - Black scoter
and Clangula hyemalis - Long-tailed duck)
during rehabilitation following oiling with Bunker C oil. Affected birds
had reduced erythrocyte
count, haemoglobin
concentration and haematocrit.
There were numerous immature erythrocytes visible in blood smears. (J1.32.w6)
- Anaemia was noted two days after ducks were experimentally dosed with
2 g/kg bodyweight of fuel oil by stomach tube. (J40.30.w2)
- Elevated non-protein nitrogen concentrations were noted after ducks
were given diesel oil or fuel oil by stomach tube. (J40.30.w2)
- Plasma cholinesterase levels were significantly depressed in ducks
experimentally dosed with high doses of certain petroleum oils (diesel
and a cutting oil); these oils contained organic phosphates. (J40.30.w2)
Chronic effects:
- Reproductive effects - decreases in egg laying, fertilization rates and
hatchability of eggs have all been reported in waterfowl following ingestion of oil.
- Reduced growth and development.
- Sea ducks Histrionicus histrionicus - Harlequin duck
and Bucephala islandica - Barrow's goldeneye,
sampled in 1996-1998 from areas of Prince William Sound, Alaska, which
were heavily oiled during the Exxon Valdez oil spill in 1989, had
significantly raised cytochrome P450 1A (known to be induced by
oil-derived PAHs) compared to ducks of the same species from non-oiled
areas, indicating probable exposure to oil. Certain polychlorinated
biphenyl (PCB) congeners can also induce P450 1A, but were not
detected in the ducks' tissues. The enzyme induction may be due to
foraging on benthic invertebrates, which do not rapidly metabolise
PAHs.
It is possible that the remaining oil may have individual and population
level effects, particularly for ducks like Histrionicus histrionicus - Harlequin duck
which are at the lower end of the body mass range for sea duck survival
in the subarctic. Records show that populations of some bird species,
including Histrionicus histrionicus - Harlequin duck,
have not fully recovered since the spill. (J313.40.w2)
N.B. secondary infections may be seen, associated with
immunosuppressive effects of ingested oil. Aspergillosis is a
common secondary problem in waterfowl (particularly seaducks such as eiders) being treated
following oiling. Other problems including pododermatitis (Bumblefoot), hock
swelling (Gout (with special reference to waterfowl)),
keel sores (Keel Lesions) and feather damage
(e.g. Feather Rot) also may be seen in birds during rehabilitation.
(J1.32.w6, J4.187.w1,
J22.220.w1, J26.22.w1,
J40.30.w2, J313.40.w2,
B11.35.w3, B15,
B16.18.w1, B20.13.w10,
B36.42.w42, D183.w3, P4.1990.w1,
P9.1.w3,
P10.28.w1,
P14.5.w7)
|
| MAMMALS |
Effects of oil on marine mammals may include "physical fouling,
thermal imbalance, changes in enzymatic activity in the skin,
interference with swimming, eye irritation and lesions, contamination
of young, and occasional mortality." (B369.w5)
Pelage & Skin:
- It may be possible to smell oil contamination on the affected
casualty. (B20.13.w10)
- Particularly on individuals in which the pelage is normally pale in
colour the individual may appear discoloured, dirty or unkempt. This
is particularly obvious if the petroleum product involved is dark in
colour. (B20.13.w10)
- Oil may cover the whole body or may be found in patches, such as on
the top of the head, the head and neck, or the head, neck and anterior
body, indicating probable rising out of the water through oil, or in
patches on the belly, sides or back. All these patterns were seen in harbour seals (Phoca vitulina - Common seal)
following oil exposure in Prince William Sound (Exxon Valdez spill).
(B377.12.w12)
- Dermatitis may be noted. (B20.13.w10,
D183.w3,
P14.2.w1)
- Some harbour seals (Phoca vitulina - Common seal)
following oil exposure in Prince William Sound (Exxon Valdez spill)
showed dry, scaly skin. (B377.12.w12)
- Chemical burns were reported in two oiled Galapagos sea lions Zalophus
wollebaeki (Otariidae - Sea lions (Family))
following the Jessica oil spill in 2001; this was presumed to
be caused by solar heating of oil exposed on skin. (J313.47.w1)
- Experimental exposure of patches of the skin of Tursiops truncatus - Bottlenose dolphin,
Grampus griseus
- Risso's dolphin and a Physeter macrocephalus
- Sperm whale showed temporary decreases in circulatory perfusion in the contact area and transient damage
(detected in skin biopsies) to cells in the epidermis, with the stratum germinativum and dermis affected only by longer exposures. there
appeared to be an inhibition of phospholipid synthesis activity following exposure to crude oil or
gasoline; wound healing was not affected. (B378.7.w7)
- Oiled individuals may concentrate on grooming more than normal. (J17.20.w1,
J30.52.w1, B368.10.w10)
- Ursus maritimus - Polar
bears, exposed to oil by being placed in an oil-covered pool, groomed
their paws and forelegs intensively and also tried to remove oil
by means such as rubbing on the bars of the cage, or in snow.
Grooming decreased over a period of five days despite the
continuing presence of oil on the coat. (B368.10.w10)
Thermoregulatory:
- Mammals which depend on their pelage rather than on a blubber layer
for insulation may appear wet and chilled. (B20.13.w10)
- Body temperature may be unstable (B20.13.w10);
either hypothermia or hyperthermia may occur due to the effects
of oil on the pelage causing clumping of the fur and removing the insulating air layer. (D183.w3,
J30.60.w1, P14.2.w5)
- In Enhydra lutris - Sea otters, pelt studies have shown a
two- to four-fold increase in thermal conductance when oiled pelts
are immersed in sea water. (J30.66.w2)
- Oiled Enhydra lutris - Sea otters
have an increased energy
requirement in order to maintain body temperature in cold or even
cool (15 °C) water. (J30.60.w1)
- Increased thermal conductance, energy expenditure and food
intake has been demonstrated for the muskrat Ondatra zibethica
(Muridae - Rats, mice, voles, gerbils etc. (Family))
after experimental oiling. (J30.52.w1)
- Decreased core body temperature was observed in an Ursus maritimus - Polar
bear when oiled by being placed in an oil-covered pool and then exposed
to windy conditions at -16 to -24°C. (B368.10.w10)
- Compared to before oiling, subcutaneous temperature rose
from 34.8 to 35.7 °C and core body temperature decreased from
36.8 °C to 36.5 °C; in the presence of wind, temperatures
decreased by approximately 1 °C. It was calculated that
although the increase in subcutaneous temperature was only
1°C, overall heat loss was considerable and bears would need
1.5 times normal food energy intake. (B378.7.w7)
- Additionally, in running bears, temperatures, particularly
core body temperature, increased proportionately more in oiled
bears, suggesting that oiled bears could risk hyperthermia
while running. (B378.7.w7)
General:
- Weight loss and loss of body condition, probably due to increased metabolic
demand, hypoglycaemia, lethargy and anorexia. (B20.13.w10)
- Dehydration. (B20.13.w10)
- Anaemia (pale mucous membranes); (B20.13.w10)
Locomotion/Exercise effects:
- Affected animals may be beached (B20.13.w10)
or avoid entering the water. (J30.52.w1)
- Swimming ability may be impaired; (D183.w3,
P14.2.w1)
individuals in the water may float lower in the water than normal
due to loss of buoyancy. (B20.13.w10)
- Harp seals (Phoca groenlandicus - Phoca - (Genus))
covered with Bunker C oil had difficulty in swimming and may have died of exhaustion.
Halichoerus grypus - Grey seal pups off the coast of
Wales may also have had difficulties swimming due to heavy oiling. (B378.7.w7)
- North American river otters (Lontra canadensis
- Canadian otter) experimentally
exposed to oil (Prudhoe Bay crude, weathered for two weeks) in food,
at 0.1 g oil every other day or 1.0 g oil every other day, showed
reluctance to bound rather than walk on a treadmill and showed higher
oxygen consumption when walking than did control otters. Oil-exposed
otters also showed reduced numbers of dives when chasing fish,
compared with control animals; this could reduce prey capture rates.
(J30.78.w1)
Gastro-intestinal signs:
- Diarrhoea may occur. (B20.13.w10)
- Both oil toxicity and stress are believed to have
contributed to gastrointestinal haemorrhage (resulting in melaena) and
chronic gastric erosion. (B20.13.w10)
- Ingestion of oil may cause gastrointestinal haemorrhage in Lutra lutra - European otter.
(P14.2.w1)
- Spraints (faeces) may visibly contain oil. (J17.20.w1)
- In three Ursus maritimus - Polar
bears exposed to oil by being placed in an oil-covered pool, and which
ingested oil while grooming their contaminated fur, vomiting and
diarrhoea were noted. (B368.10.w10)
Respiratory signs:
- Respiratory distress may be noted. (B20.13.w10,
D183.w3)
- Inhalation may lead to pneumonia. (D183.w3)
- Dyspnoea in Enhydra lutris - Sea otters, with
resultant interstitial pulmonary emphysema. (B20.13.w10)
- Inhalation of volatile hydrocarbons may result in
mucous membrane inflammation, pulmonary oedema, pulmonary haemorrhage
and pneumonia. (P24.327.w4)
Ocular lesions:
- Ocular irritation appears to be a common feature of oiling in
pinnipeds. (J320.8.w1)
- Conjunctivitis is recognised as a common sign. (B20.13.w10,
D183.w3,
P14.2.w1)
- Excessive lachrymation,
acute conjunctivitis, swollen nictitating membranes, opacity of
the cornea, corneal abrasion and even corneal ulceration may be
noted; these may be common findings in oiled seals. (B335.15.w15,
B378.7.w7)
- Harbour seals (Phoca vitulina - Common seal)
following oil exposure in Prince William Sound (Exxon Valdez spill)
sometimes appeared to have difficulty in keeping their eyes open.
(B377.12.w12)
- Conjunctivitis and corneal ulceration have been seen in oiled seals. (D183.w3)
- Corneal lesions attributable to oil exposure were observed in
harbour seals (Phoca vitulina - Common seal)
oiled in the Exxon Valdez spill in Prince William Sound,
Alaska, in 1989. (D162.5.w5)
- Ringed seals Phoca hispida (Phoca
- (Genus)) experimentally exposed to water covered in crude oil
quickly started excessive lachrymation and after a while had difficulty in keeping their eyes open. Severe conjunctivitis, swollen nictitating
membranes and corneal abrasions and ulceration were noted within 24 hours, but the
inflammation reduced once the seals were placed in clean water. (B368.4.w4,
B378.7.w7)
- Ocular problems may be exacerbated by highly viscous weathered oil
due to the tenacity of the substance and its ability to trap debris such as sand and
sticks. (B368.4.w4)
CNS signs:
- CNS signs
seen in oiled mammals may include weakness, lethargy, muscle
fasciculations, ataxia, paralysis and seizures. These may be due to
petroleum toxicity, particularly after contact with volatile agents,
or may be related to secondary effects of oiling: hypoglycaemia,
hypothermia or hyperthermia, electrolyte imbalances, or trauma. (D208.5.w5)
- CNS signs may also be due to other illness present at the time
of oiling. (D208.5.w5)
- Lethargy has been noted. (B20.13.w10,
B377.12.w12)
- Neurological abnormalities such as disorientation and coma. (B20.13.w10)
- Reduced reactions to humans. (B377.12.w12,
D183.w3)
- Oiled individuals may be easier to catch than their non-oiled
counterparts. (B20.13.w10)
- Some harbour seals (Phoca vitulina - Common seal)
following oil exposure appeared sick, lethargic and tame (allowing
close approach). Behavioural changes were thought to be associated
with damage to brain neurons due to hydrocarbon toxicity. (B377.12.w12,
D183.w3)
- In harbour seals (Phoca vitulina - Common seal)
following oil exposure in Prince William Sound (Exxon Valdez spill),
deaths occurred probably due to neuronal damage thought to be related
to inhalation of short-chain aromatic hydrocarbons. (B377.17.w17)
- In Mustela vison - American mink
experimentally exposed to oil externally (either a 1.5 cm-thick slick
of Alaskan North Slope crude oil on seawater for one minute, or a 1.5
cm-thick slick of bunker C fuel oil on seawater for one minute) or
internally by being fed diets containing 500 µg of Alaskan North
Slope crude oil or of bunker Coil per gram of food, behavioural
changes were seen in the externally-exposed mink for five to 15 days,
including lethargy or stupor, lateral or dorsal recumbency and
blindness. The signs were compatible with hepatic toxicosis leading to
hepatic insufficiency and thereby CNS abnormalities. (J13.61.w1)
Examples of clinical signs in different species:
- In Enhydra lutris - Sea otters
oiled in the Exxon Valdez
spill, depression, respiratory distress (associated with interstitial
emphysema) and diarrhoea were noted. Animals which did not survive
after being taken into care for rehabilitation died from stress and shock. (B368.8.w8)
- Skin ulceration,
gastro-intestinal tract bleeding, respiratory distress and respiratory
tract bleeding have been seen in oiled seals. (D183.w3)
- Subadult crabeater seals Lobodon carcinophagus (Phocidae - Seals (Family))
oiled by diesel from the Bahia Paraiso in Antarctica were observed listless and with blood-tinged nasal
discharge and blood-tinged
faeces. (B368.4.w4)
- Some harbour seals (Phoca vitulina - Common seal)
pups had elevated blood hydrocarbon levels and "appeared
unhealthy" for a time following the Exxon Valdez
spill in Prince William Sound, Alaska, in 1989, but all recovered. (D162.5.w5)
- Enhydra lutris - Sea otters
which died after being oiled in the Sea Empress spill and taken for
rehabilitation, most commonly showed a terminal shock syndrome with hypothermia, lethargy and commonly haemorrhagic
diarrhoea. This was more common (72% versus 22%), and occurred more rapidly, in heavily oiled otters versus lightly oiled otters, indicating that oiling was an important contributing factor in development of the condition, although there may also have been a role or reaction to confinement and handling. In heavily or moderately oiled otters, shock was present at the time
of presentation or developed within 48 hours, while in lightly oiled
otters it developed during the second week in captivity. Anorexia was
common in the otters and convulsions were often seen terminally. (J26.32.w1)
- In domestic cattle calves given "sweet" (low sulphur)
crude oil, "sour" (high sulphur) or kerosene, by stomach
tube, clinical signs included anorexia, significant weight loss, mild
depression and in most cases decreased plasma glucose. Oil was visible
in the faeces of all individuals given multiple doses of oil, and
those of some individuals given kerosene or sweet crude became rather
dry. Vomiting and moderate to extreme bloating were noted with the
crude oils, particularly the volatile sweet crude oil, but not with
the kerosene. Clinical signs of pneumonia and pleuritis (due to
aspiration pneumonia) with shallow rapid respiration, increased heart
rate, lowered head and neck, reluctance to move, anorexia, depression,
weakness, constipation, oil-stained mucous discharge, a dehydrated
appearance, and in some animals also shivering, slight incoordination,
head bobbing and mental confusion were noted in some calves given kerosene
or sweet crude oil. (J4.162.w1)
IN BEARS
- In three Ursus maritimus - Polar
bears exposed to oil by being placed in an oil-covered pool, and which
ingested oil while grooming their contaminated fur, abnormal (excessive) grooming, vomiting, diarrhoea,
depression and anorexia were noted. One bear died, a second was
euthanased, due to renal failure, and the
third required extensive treatment. (B378.7.w7,
B368.10.w10, P1.1980.w9)
Clinical pathology:
- Note: Haematological and biochemical data can be very
important for clinical decisions regarding treatment of oiled animals,
however in clinical oiling situations it is generally not possible to
distinguish between direct (toxic and/or stress) effects of the oil
and those related to stress of capture, handling and rehabilitation
procedures. (J13.61.w1)
- In Enhydra lutris - Sea otters
oiled following the Exxon Valdez spill and taken in for rehabilitation, common haematological abnormalities were lymphopaenia and leucopaenia, often with a
left shift and anaemia. Biochemically, azotaemia (probably prerenal in most cases, associated with shock or dehydration), hyperkalaemia (probably related to diarrhoea and gastrointestinal haemorrhage), hypoglycaemia (probably due to anorexia), elevated serum transaminases (indicating hepatocellular leakage and probably associated with anorexia) and hypoproteinaemia/hypoalbuminaemia (probably related to diarrhoea and gastrointestinal haemorrhage)
were recorded. Heavily oiled otters showed more clinical pathological abnormalities than did lightly oiled otters.
(J26.32.w1)
- Note: severe leukopaenia and a left shift seen in oiled Enhydra lutris - Sea otters, indicating a severe inflammatory response, may be partly due
to severe stress and use of corticosteroids. (B20.13.w10)
- Levels of various liver enzymes such as AST and ALT
may be increased. (B20.13.w10)
- In harbour seal (Phoca
vitulina - Common seal) pups oiled following the Exxon
Valdex oil spill and taken in for cleaning and rehabilitation,
blood LDH (lactate dehydrogenease) levels were high initially and then
fell rapidly; the high levels were thought to be related to the "stresses
associated with oiling, capture and handling." (B377.13.w13)
- Anaemia was noted in some Enhydra lutris - Sea otters
during
rehabilitation following the Exxon Valdez oil spill. (P14.3.w28)
- Reduced PCV was noted in two harbour seal (Phoca
vitulina - Common seal) pups captured early during the Exxon
Valdez spill, and which did not survive. The exact cause of the
reduction in PCV was not clear; factors which were considered to have
contributed to the deaths of the pups included contamination with oil
early in the spill, multiple transfers between facilities and
inconsistencies in feeding and rehabilitation protocols. (B377.13.w13)
- Anaemia may result from absorption of volatile hydrocarbons. (P24.327.w4)
- In North American river otters (Lontra canadensis
- Canadian otter)
experimentally exposed to oil (Prudhoe Bay crude, weathered for two
weeks) in food, at 0.1 g oil every other day or 1.0 g oil every other
day, haemoglobin levels declined compared to control otters. (J30.78.w1)
- In Mustela vison - American mink
experimentally exposed to oil externally (either a 1.5 cm-thick slick
of Alaskan North Slope crude oil on seawater for one minute, or a 1.5
cm-thick slick of bunker C fuel oil on seawater for one minute) or
internally by being fed diets containing 500 µg of Alaskan North
Slope crude oil or of bunker Coil per gram of food, changes were seen
in a wide variety of haematological and biochemical parameters. (J13.61.w1)
- In samples taken one week after exposure, red blood cell count,
white blood cell count, segmented neutrophil counts and relative
frequencies and fibrinogen levels showed significant variances between groups; differences were greatest for those externally
exposed to Bunker C fuel oil. The increase in red cell count may
have indicated a stress response causing splenic contraction and
rbc release; leucocytosis in mink exposed to bunker C fuel oil but
not to Alaska North Slope crude may indicate a higher
physiological stress associated with the bunker C oil.
Biochemically, individuals exposed externally had significantly
altered values compared with control mink, with alterations in
sodium (decreased), chloride (decreased), calcium (decreased),
creatinine (increased), total protein (decreased), alanine
transaminase (ALT) (increased), creatine kinase (CK) (decreased),
alkaline phosphatase (AP) (increased) and gamma-glutamyltransferase
(GGT) (increased); alterations were greatest for the mink exposed
to the crude oil. Changes in sodium, chloride and calcium may have
been associated with GIT disturbances including anorexia and
diarrhoea, while decreased sodium and chloride may also have been
associated with toxic effects of oil ingested by grooming. The
decreased CK in externally exposed mink relative to the other
groups was probably because these animals were relatively
lethargic and inactive, therefore showed less resistance to
capture. The increased ALT, AP and GGT, and reduced total protein,
were consistent with liver toxicity; the increased creatinine
indicated direct toxic effects on the kidneys with possibly
decreased glomerular filtration. (J13.61.w1)
- In samples taken after the mink had weaned their pups, while all
mean values for haematological parameters were within reference
ranges for this species, mean reticulocyte counts were decreased
and segmented neutrophil counts were lower, while the number of
leucocytes was increased. Effects were most severe in individuals
exposed to bunker C fuel oil in the diet; those exposed to Alaska
North Slope crude in their diet showed similar changes of a lesser
degree while mean reticulocyte values in externally exposed mink
were also lower than in controls. The reduced number of
neutrophils in mink following ingestion of oil may indicate
reduced neutrophil production, possibly due to toxic effects on
haematopoietic stem cells. Biochemically, differences from controls
were seen in aspartate transferase (AST) (higher), alkaline
phosphatase (higher), gamma-glutamyltransferase (higher), lactate
dehydrogenase (higher) and cholesterol (higher). Raised AST, AP,
LDH and cholesterol in externally exposed mink, raised GGT in mink
internally exposed to bunker C fuel oil, and raised LDH all
indicated mild hepatic damage. (J13.61.w1)
- "An animal that has truly recovered would be expected to
have serum LDH activity and values for other hepatic enzymes within
reference ranges at the time of release." (J13.61.w1)
- In domestic cattle calves given "sweet" (low sulphur)
crude oil, "sour" (high sulphur) or kerosene, by stomach
tube, some calves developed a reduced plasma glucose content; this was
a consistent finding in those given the sour crude. In calves
developing aspiration pneumonia due to the oil, findings included mild
to moderate haemoconcentration (increased PCV, haemoglobin, total
proteins and BUN), together with transient hyperglycaemia (108 to 168
mg/100 mL) and initial leucopaenia (reduced neutrophils,
lymphocytes
and eosinophils) followed over two to three days by a relative
increase in neutrophils while the total WBC count either remained
lowered, returned to normal, or became elevated. (J4.162.w1)
- Note: Changes in blood parameters can be complex, with
interactions between components of responses, and associated with
other factors such as season and diet, which may give misleading
results if only one parameter is measured. (J1.37.w3)
IN BEARS
- In Ursus maritimus - Polar
bears exposed to oil by being placed in an oil-covered pool, peripheral
haemolysis, erythropoitic dysfunction and renal abnormalities were
notable: microcytic hypochromic anaemia, elevated serum
bilirubin, urea, creatinine, uric acid and inorganic phosphate were
detected as well as hyponatraemia; increased cholesterol and plasma
cortisol indicated an exposure-related stress response. (B378.7.w7,
P1.1980.w9)
- Urine was dark, specific gravity 1.012, and contained blood and a
small amount of protein. (P1.1980.w9)
Long-term & population effects:
- Enhydra lutris - Sea otters,
sampled in 1996 to 1998, in areas
of Prince William Sound, Alaska, that were heavily oiled by the Exxon
Valdez oil spill in March 1989, showed significantly higher
induction of phytochrome P450 1A (an indicator of exposure to PAHs)
than did otters from unoiled areas, indicating continued exposure to
oil. Sea otter populations in the oiled area have also shown a slower
population recovery than expected and analysis of carcass collection
data indicates that sea otters in the oiled area have had reduced
survival. Reduced survival was greatest for animals born prior to the
spill but was still evident in young animals born after the spill.
Animals from young cohorts at the time of the spill (e.g. yearlings at
the time of the spill) showed substantially higher mortality rates in
the first years after the spill and improved annual survival later,
while mature breeding animals (five years and older) have shown
strongly increasing mortality rates with time. (J135.97.w2)
|
| REPTILES |
- Sea turtles may float unevenly. (B20.13.w10)
- In sea turtles, dermatological damage, respiratory effects, decreased
digestive efficiency, haematological damage and associated immune
reaction and decreased salt gland efficiency may occur. (B369.w6)
- Tar may be present caked in the mouth, oil may be present on the
animal and locomotion may be impaired (particularly in hatchlings. Oil
may also be found in the nares, eyes and faeces. (D228.4.w4)
- Chelonia (Testudines - Turtles and Tortoises (Order))
soiled with diesel have shown ocular irritation, dermatitis
and lethargy soon after oiling, followed by development of respiratory
distress and sloughing of skin, later broken nails and chipped beaks,
also secondary bacterial cutaneous ulcerative disease with Citrobacter
freundii. (P14.4.w3)
- Lesions on the plastron developed initially as pinpoint pale
yellow spots, which developed to a network of fine yellow
striations and in some animals continued to reddening of the
plastron and ulcerative lesions of the shell. (P14.4.w3)
- Skin and exposed mucous membranes:
- Caretta caretta - Loggerhead
turtles experimentally
exposed to oil showed sloughing of mucous membranes (periorbital
conjunctiva, nasal and oral mucosa) and skin, particularly the
skin of the neck, inguinal region and axillae. Under the slough,
the skin was soft and light red in colour; it lacked the normal
leathery texture of turtle skin. Skin was grossly normal by 40
days after exposure to oil. (P14.3.w29)
- Note: the nature of the inflammatory response could
break the integumentary barrier and allow entry of pathogenic
organisms, resulting in localised bacterial infection and even
septicaemia. (P14.3.w29)
- Young sea turtles may die as a result of eating tar balls. (B369.w6)
Clinical pathology:
- Up to a four-fold increase in leucocyte count, 50% reduction in red
blood cell count and polychromasia were noted in Caretta caretta - Loggerhead
turtles experimentally
exposed to oil. Glucose levels were also reduced, but other serum
chemistry values were less affected. (D228.4.w4,
J52.28.w1)
|
| AMPHIBIANS |
-- |
Incubation |
BIRDS |
- Effects may be acute or chronic (B20.13.w10,
B36.42.w42).
|
| MAMMALS |
--
|
Mortality / Morbidity |
BIRDS |
- Mortality can be very high in the vicinity of oil spills.
- Detected mortality is probably lower than actual mortality, as only birds
reaching the shore are counted in marine oil spills and small numbers of birds affected by
minor spills may not be noticed.
- Long-term effects e.g. on reproduction, are difficult to quantify.
- Mortality may also occur due to predation of affected birds. (P62.14.w1)
(B20.13.w10,
B36.42.w42)
- Individuals which are already under stress, for example due to other
pollutants, may be less able to cope with the effects of oiling. (B369.w4)
- In the Exxon Valdez oil spill, Prince William Sound, Alaska,
1989, about 100,000-300,000 birds were estimated to have been killed,
or some 10%-30% of the population. (J9.342.w1)
|
| MAMMALS |
Recorded mortality of mammals
following oil is variable.
- Nearly 1,000 Enhydra lutris - Sea otters
died following the Exxon Valdez oil
spill. (B368.8.w8)
- Enhydra lutris - Sea otters
have been found dead associated
with various oil spills (more than 100 in a spill in the Kuril Islands
in 1946), while oil has also been considered as a reason for
population declines in this species. (B368.8.w8)
- Thirteen Lutra lutra
- European otter were found dead following the Esso
Bernicia spill at the Sullom Voe oil terminal, Shetland in 1978.
Estimated mortality was at least 15% of the population, possibly up to
50% (depending on the estimated initial size of the population). (J17.20.w1)
- Morbidity and mortality associate with oiling in pinnipeds appears to be very variable. In some instances, and sometimes despite visible evidence of heavy oiling, effects have been
inapparent or negligible. In others, some ill-effects have been seen and/or a few individuals have been recorded dying due to the oiling, but in a few cases a number of animals have been found oiled and dead. Heavy oiling of harp seal
(Phoca groenlandicus - Phoca - (Genus))
pups with Bunker C oil in the Gulf
of St Lawrence was associated with increased mortality in the pups. Halichoerus grypus - Grey seal pups have been observed drowning after being covered with thick oil and unable to swim due to their flippers being stuck to their bodies.
(B368.4.w4)
- Harbour seals (Phoca vitulina - Common seal)
were found dead following oil exposure in Prince William Sound (Exxon Valdez spill)
with visible oiling and/or pathological lesions indicating mortality
was associated with oil exposure. (B377.17.w17)
IN BEARS
- Of three Ursus maritimus - Polar
bears exposed to oil by being placed in an oil-covered pool, one died twenty
six days after oiling and another required euthanasia three days
later. The effects of oiling may have been exacerbated by stress due
to the experimental conditions. The third bear survived but required
several months of treatment to regain normal health. (B368.10.w10,
B378.7.w7, P1.1980.w9)
|
Pathology |
BIRDS |
There are no consistent organ lesions indicative of oil exposure. (P14.2.w6)
- NOTE: It is important to recognise that findings may be
related not only specifically to toxic effects of oiling but to
oil-related stress and, in birds which have been caught and brought
into care, stress related to capture, handling etc. (B20.13.w10, J4.187.w1)
- Larus argentatus - Herring
gull adults brought into captivity, housed outside in
individual cages within sight and sound of conspecifics, and which
showed apparent behavioural adaptation, showed a 33% decrease in
pectoral muscles after 28 days in captivity (microscopically
consistent with atrophy), and multi-organ amyloidosis, with severe
amyloid infiltration of the splenic arterial walls, sometimes by
as early as four days after capture and in nearly all (six of
seven) birds by 20 days; Amyloid was noted in other sites from
eight days onward and was found in vessel walls in the liver,
kidney, thyroid, pancreas and gonads. Adrenals also showed
lesions, characterised by "moderate to severe diffuse
vacuolar degeneration of catecholamin-producing cells." (J4.187.w1)
Gross lesions:
General:
- Oil may be visible externally or found on examination of the inside
of the ears, the vent, the trachea or the gastro-intestinal tract. (B20.13.w10)
- The carcass may be dehydrated (loss of skin
elasticity, skin difficult to reflect from underlying musculature). (J3.132.w)
- Emaciation is a common finding. (B36.42.w42,
J7.19.w1)
- Larus argentatus - Herring
gull nestlings dosed with Prudhoe Bay crude oil at 10 or 20
mg/kg bodyweight orally daily, had greatly reduced subcutaneous fat;
this was not seen in Fratercula arctica - Atlantic puffin
nestlings given the same oil doses. (J26.23.w1)
- Dehydration, with tissue that were dry, sticky and dark, were found
in one of 103 Podiceps cristatus - Great crested grebe
and five of 86 Podiceps nigricollis - Black-necked grebe
necropsied after being oiled in the Arabian Gulf spill in 1991.
Emaciation was noted in 2.9% and 11.6% of the grebes respectively. (P14.3.w20)
- Dehydration, with tissue that were dry, sticky and dark, were found
in 18.3% of 71 Phalacrocorax carbo - Cormorant
and 7% of 57 Phalacrocorax nigrogularis -
Socotra cormorant (Phalacrocorax (Genus))
necropsied after being oiled in the Arabian Gulf spill in 1991.
Emaciation was noted in 4.2% and 15.8% of the cormorants respectively.
(P14.3.w20)
- Birds which die rapidly, for example due to toxic
effects of inhaled petroleum vapours, may be in good or excellent
nutritional condition. (P14.2.w7)
- In auks (mainly Uria aalge - Common murre)
oiled by the Torrey Canyon in 1967, and dying during attempted
rehabilitation, the feathers were badly stained with oil, in poor
condition, and not waterproof. In some individuals the skin appeared
damaged and feathers fell out easily. Practically all birds dying in
the first 11 weeks of attempted rehabilitation were emaciated, with
low body weight (mean only 640 g), complete loss of both subcutaneous
and visceral fat, and marked pectoral muscle atrophy. It was noted
that "the pattern of mortality and pathological changes were
strongly suggestive of severe stress and the presence of powerful
irritants or poisons in the gut." (J315.2S.w2)
- A study of Cerorhinca monocerata - Rhinoceros auklets (Laridae -
Skuas, Terns, Gulls, Puffins, Auks (Family)) in
the Southern Japan Sea found that dead oiled birds had lost one
third of body, muscle and general organ masses, 60% of liver mass,
more than 90% of subcutaneous fat and more than half of all fats
stored in muscles and other organs, including bone marrow, which
was almost entirely replaced with water. It was considered that
these birds died not from the oiling per se but from "emaciation
caused by starvation and nutritional exhaustion, accelerated by
increased energy loss." (J313.40.w3)
- In marine birds oiled in the Prestige spill in 2002 (mainly Uria aalge - Common murre,
Alca torda
- Razorbill, and Fratercula arctica - Atlantic puffin)
also gulls Larus
spp., Morus bassanus - Gannet,
Phalacrocorax
spp., Alle alle - Dovekie,
Gavia immer - Common loon,
Fulmarus glacialus
- Northern fulmar and other birds, the main findings in
birds found dead covered with oil were various degrees of oiling over
the body surface (less than 10% to 100%), dehydration (loss of skin
elasticity, skin difficult to reflect from underlying musculature),
diarrhoea (liquid faeces surrounding the cloaca), and emaciation
(severe pectoral muscle atrophy, absence of subcutaneous fat deposits,
absence of abdominal fat deposits, serous atrophy of pericardial fat).
Birds found dead but not covered in oil showed dehydration, diarrhoea
and emaciation. Birds which had died during rehabilitation had
findings of dehydration and diarrhoea, also broken feathers and skin
erosions, and varying emaciation. (J1.41.w1)
Pulmonary:
- Pulmonary haemorrhage and
oedema may indicate exposure to some volatile
components of oil. (P14.2.w7,
B23.38.w2)
- Pneumonia associated with inhalation of oil is reported sometimes. (B20.13.w10)
- Oil may be present in the trachea and the lungs may be
discoloured if oil has been inhaled. (B36.42.w42)
- Pulmonary oedema may be present due to inhalation of
fumes from oil; pneumonia may occur secondary to this. (P4.1990.w1)
- Aspiration pneumonia may be present due to aspiration
of either oil or gavage food mixtures. (P4.1990.w1,
B23.38.w2)
- Pulmonary haemorrhage was noted in some Phalacrocorax
nigrogularis - Socrata cormorants oiled during the Arabian Gulf
oil spill, January 1991, associated with the First Gulf War. (P1.1991.w1)
- Lung consolidation and oedema was noted in 17 of 30
birds necropsied following the 1991 Fidalgo Bay (Washington) spill of
crude oil. (P14.4.w14)
- Pulmonary congestion and "cloudiness" of
the air sacs was commonly noted in birds
oiled with Kuwait crude following the Torrey Canyon spill. (J7.19.w1)
- Pale watery fluid was noted "occasionally" in the
lungs and airsacs of Podiceps cristatus - Great crested grebe
(12.6%) and Podiceps nigricollis - Black-necked grebe
(15.1%) necropsied after being oiled in the Arabian Gulf spill in
1991. (P14.3.w20)
- In auks (mainly Uria aalge - Common murre)
oiled by the Torrey Canyon in 1967, lungs of birds dying within
the first four days after being found generally showed acute
congestion; pneumonia was noted in some individuals. Air sacs were
often cloudy. In birds which survived four days to three weeks,
changes were similar; additionally, aspergillosis was found in three
birds. In those surviving longer than this, aspergillosis was noted in
11 of 25 birds while lung congestion was noted in seven and cloudy air
sacs in five. Drowning was also noted as a diagnosis in one or a few
birds [data unclear].(J315.2S.w2)
- In marine birds oiled in the Prestige spill in 2002 (mainly Uria aalge - Common murre,
Alca torda
- Razorbill, and Fratercula arctica - Atlantic puffin)
also gulls Larus
spp., Morus bassanus - Gannet,
Phalacrocorax
spp., Alle alle - Dovekie,
Gavia immer - Common loon,
Fulmarus glacialus
- Northern fulmar and other birds, in 28% of birds which
had died during rehabilitation there were multiple small whitish
fungal plaques in the lungs, air sacs, kidney and liver (disseminated Aspergillosis).
(J1.41.w1)
Gastro-intestinal tract:
- Gastro-intestinal tract mucosa may be reddened; lumen may contain
blood and/or oil. (B36.42.w42)
- Oil may be present around the vent. (B36.42.w42)
- Haemorrhagic enteritis may occur. (P14.1.w17)
- Severe enteritis with coagulative necrosis and haemorrhage was
noted in many birds (mainly Uria aalge - Common murre)
oiled with Kuwait crude following the Torrey Canyon spill.
(J7.19.w1)
- In grebes (Podicipedidae - Grebes (Family))
impaction of the gizzard with bile-stained feathers may be noted. (P1.1991.w1)
- Oil was found in the intestinal lumen of 11 of 30
birds necropsied following the 1991 Fidalgo Bay (Washington) spill of
crude oil. No associated enteritis was seen. (P14.4.w14)
- Oil was not found in the gastro intestinal
tract of Larus argentatus - Herring
gull nestlings dosed with Prudhoe Bay crude oil at 10 or 20
mg/kg bodyweight orally daily, although Fratercula arctica - Atlantic puffin
nestlings given the same oil doses often had mild oil staining of the
ventricular cuticle and the intestines often contained small globules
of oil. No gross lesions were found in these birds. (J26.23.w1)
- Signs of oil were found in the jejunum, caeca and
colon of 22.3% of Podiceps cristatus - Great crested grebe
and 17.4% of Podiceps nigricollis - Black-necked grebe
necropsied after being oiled in the Arabian Gulf spill in 1991. (P14.3.w20)
- Inflammation of the small intestine, with petechiae
or larger haemorrhages, was seen in 50.5% of Podiceps cristatus - Great crested grebe
and 33.7% of Podiceps nigricollis - Black-necked grebe
necropsied after being oiled in the Arabian Gulf spill in 1991; a few
birds had proventriculitis, one had colitis. (P14.3.w20)
- Cloacal impaction with urinary material was found in seven of
189 Podiceps cristatus - Great crested grebe
and 35% of Podiceps nigricollis - Black-necked grebe
necropsied after being oiled in the Arabian Gulf spill in 1991. (P14.3.w20)
- Gastrointestinal tract inflammation (usually haemorrhagic suffusion
of the walls of the small intestine, but with 12 cases of
proventriculitis and one of colitis) was noted in 63.4% of 71 Phalacrocorax carbo - Cormorant
and 45.6% of 57 Phalacrocorax nigrogularis -
Socotra cormorant (Phalacrocorax (Genus))
necropsied after being oiled in the Arabian Gulf spill in 1991. Signs
of ingested oil were seen in 10% and 28.1% respectively, mainly in the
proventriculus, small intestine and colon. (P14.3.w20)
- In auks (mainly Uria aalge - Common murre)
oiled by the Torrey Canyon in 1967, enteritis was a common
finding in birds dying in the first four days of attempted
rehabilitation, with the most severe lesions in the duodenum.
Enteritis was considered to be simple inflammatory in some birds,
severe haemorrhagic with severe loss of blood in some birds, and in
some there was a coagulative necrotic condition with sloughing of the
mucosa. (J315.2S.w2)
- In marine birds oiled in the Prestige spill in 2002 (mainly Uria aalge - Common murre,
Alca torda
- Razorbill, and Fratercula arctica - Atlantic puffin)
also gulls Larus
spp., Morus bassanus - Gannet,
Phalacrocorax
spp., Alle alle - Dovekie,
Gavia immer - Common loon,
Fulmarus glacialus
- Northern fulmar and other birds, the main findings in
birds found dead covered with oil included diarrhoea (liquid faeces
surrounding the cloaca) while within the ventriculus, proventriculus
and intestines, dark material (similar to that on the skin, consistent
with oil), was found, also petechiation of the mucosa. Birds found
dead but not covered in oil showed diarrhoea and in some birds oil in
the intestines. Birds which had died during rehabilitation had
diarrhoea and a few had ventricular ulcers. (J1.41.w1)
Liver:
- Liver abnormalities, mainly discolouration,
parenchymal swelling and increased fragility, was noted in 24.3% of Podiceps cristatus - Great crested grebe
and 23.5% of Podiceps nigricollis - Black-necked grebe
necropsied after being oiled in the Arabian Gulf spill in 1991. (P14.3.w20)
- In auks (mainly Uria aalge - Common murre)
oiled by the Torrey Canyon in 1967, hepatitis was noted in some
birds. (J315.2S.w2)
- In marine birds oiled in the Prestige spill in 2002 (mainly Uria aalge - Common murre,
Alca torda
- Razorbill, and Fratercula arctica - Atlantic puffin)
also gulls Larus
spp., Morus bassanus - Gannet,
Phalacrocorax
spp., Alle alle - Dovekie,
Gavia immer - Common loon,
Fulmarus glacialus
- Northern fulmar and other birds, in 28% of birds which
had died during rehabilitation there were multiple small whitish
fungal plaques in the lungs, air sacs, kidney and liver (disseminated Aspergillosis).
(J1.41.w1)
Kidneys:
- Nephropathy was noted in 23% of Podiceps cristatus - Great crested grebe
and 10.5% of Podiceps nigricollis - Black-necked grebe
necropsied after being oiled in the Arabian Gulf spill in 1991. (P14.3.w20)
- Nephropathy was noted in found in 29.6% of 71 Phalacrocorax carbo - Cormorant
and 24.6% of 57 Phalacrocorax nigrogularis -
Socotra cormorant (Phalacrocorax (Genus))
necropsied after being oiled in the Arabian Gulf
spill in 1991. (P14.3.w20)
- Kidneys were enlarged in birds following the 1991
Fidalgo Bay (Washington) spill of crude oil. No associated primary
histopathological lesions were found. (P14.4.w14)
- In auks (mainly Uria aalge - Common murre)
oiled by the Torrey Canyon in 1967, kidney lesions were noted
in two of 14 birds dying within a day of being brought for
rehabilitation. In 22 of 33 birds dying at one to four days kidneys
were often paler than usual (light brick red rather than dark red
brown), and "excessive amounts of excretory products"
were found in the tubules and ureters, while one individual showed
fatty change. Renal changes were also noted in five of 11 birds which
survived four days to three weeks and in 13 of 25 birds dying after
this time. (J315.2S.w2)
- In marine birds oiled in the Prestige spill in 2002 (mainly Uria aalge - Common murre,
Alca torda
- Razorbill, and Fratercula arctica - Atlantic puffin)
also gulls Larus
spp., Morus bassanus - Gannet,
Phalacrocorax
spp., Alle alle - Dovekie,
Gavia immer - Common loon,
Fulmarus glacialus
- Northern fulmar and other birds, in 28% of birds which
had died during rehabilitation there were multiple small whitish
fungal plaques in the lungs, air sacs, kidney and liver (disseminated Aspergillosis).
(J1.41.w1)
Musculo-skeletal:
|
