LOS ANGELES, CA (Catholic Online) - Scientists say that approximately 15 percent of coral trout in Australia's Great Barrier Reef have cancerous lesions on their scales. This likens the fish to the fate of human Australian humans, where two in three people there will be diagnosed with skin cancer before the age of 70, the highest rate in the world.

The cancerous fish has come as a most unwelcome surprise for all concerned. Scientists from the Australian Institute of Marine Science were near the Great Barrier Reef conducting a survey of shark prey when they kept seeing strange dark patches on the normally bright orange fish. Another research team from the University of Newcastle in England was also studying coral disease in the area.

Michael Sweet, a coral disease expert said that "We can check for microbial pathogens quite easily. So we designed an experiment, screened for them, and couldn't find anything. So we had to look deeper."

The research team's first guess was that the patches were caused by an infection. Sweet and his colleagues cut the fish tissue into slices and put them under a microscope. "We basically stumbled onto these tumor formations," he said.

The team then compared them with samples from fish that had been given melanoma, the deadliest form of skin cancer - as part of a laboratory experiment. They looked nearly identical.

It is unlikely the phenomenon is new, Michelle Heupel, a researcher at the Australian Institute of Marine Science who wrote the study with Sweet and others.

"When I talk to people who have been fishing for a long time, they tell me they've seen this since back in the 1980s," she said.

It's not yet known why the incidence of melanoma was so high in these fish. Sweet points out that the reef sits under the outer reaches of the ozone hole centered over Antarctica. That greatly increases the area's exposure to harmful ultraviolet radiation, which can lead to cancer-causing mutations in DNA.

The Great Barrier Reef's location at the edge of the coral trout's range also increases its vulnerability to cancer.

"They are at the extreme of their habitat," Sweet said. "They are struggling to cope, which means they will be more susceptible to more diseases."

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