Tazi Pillips, Global Animal
August 2012
Read on to find out how the depletion of ozone in the earth’s atmosphere is not only harmful to terrestrial beings, but animals in the oceans as well.
A new discovery shows that coral trout in the waters of Australia’s Great
Barrier Reef have developed skin cancer, similar to melanoma in humans.
Scientists have related the symptoms to UV rays passing through the largest
hole in the ozone. This finding is the first case of skin cancer in fish
outside of laboratory tests, in the natural environment.
Read on to find out how the depletion of ozone in the earth’s atmosphere is
not only harmful to terrestrial beings, but animals in the oceans as well.
— Global Animal
From Discovery News, LiveScience Staff
The first case of skin cancer in a wild marine fish population looks eerily
similar to the melanoma that plagues humans, researchers report today (Aug.
1).
Coral trout living on Australia’s Great Barrier Reef are directly beneath
the Antarctic ozone hole, the world’s largest, which is the result of the
depletion of ozone in the atmosphere that normally protects humans from
harmful UV rays.
“Further work needs to be carried out to establish the exact cause of the
cancer, but having eliminated other likely factors such as microbial
pathogens and marine pollution, UV radiation appears to be the likely
cause,” study researcher Michael Sweet, of Newcastle University in the
United Kingdom, said in a statement.
Sweet and his colleagues examined 136 common coral trout (Plectropomus
leopardus), and found 20 individuals, or 15 percent, showed dark skin
lesions. The lesions ranged in size from small (covering just 5 percent of
the skin) to large, covering the fish’s full body, they report online in the
journal PLoS ONE.
“The individuals we looked at had extensive — but only surface — melanomas,”
Sweet said. “This means the cancer had not spread any deeper than the skin,
so apart from the surface lesions, the fish were basically healthy.”
The lesions looked nearly identical to skin cancer found in humans, he said.
Once the melanoma spreads, Sweet added, fish would likely show signs of
sickness, becoming less active and maybe feeding less. As such, the sick
fish would be less likely to get caught. “This suggests the actual
percentage affected by the cancer is likely to be higher than observed in
this study,” Sweet said in the statement.
While the diseased fish were caught around Heron Island and One Tree Island,
the researchers do not know how many coral trout living elsewhere on the
reef have skin cancer.
Until now, researchers had reported melanoma caused by UV exposure in fish
only in lab conditions; these fish have been used as a model for studying
human skin cancer.
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