Fisho’s shock at study revealing dramatic shark decline
A CAIRNS fishing charter operator is in disbelief after learning of a new study which reports the number of oceanic sharks and rays worldwide has fallen by 71 per cent since 1970.
James Cook University's Professor Colin Simpfendorfer and Dr Cassandra Rigby were part of an international team of authors that found dramatic declines after they calculated two biodiversity indicators for oceanic sharks and rays worldwide.
The paper was a project of the Global Shark Trends Project and found "the risk of extinction to marine species is primarily caused by overfishing".
"The authors (of the study) attribute this decline to an 18-fold increase in relative fishing pressure - a measure of the proportion of sharks and rays caught relative to their global population - over the period," the research read.
Of the 31 species tested, it found 24 were now threatened with extinction, and three species (the oceanic whitetip, the scalloped and great hammerhead sharks) had declined so sharply that they were now classified as critically endangered.
Prof Simpfendorfer said despite the bad news, great white sharks and the great hammerhead shark populations in the Northwest Atlantic appeared to be recovering due to strict US laws now protecting them.
"Fishing limits are needed immediately to prevent shark and ray population collapses. Governments should adopt, implement, and enforce - at domestic and regional levels - science-based catch limits and other protective measures," professor Simpfendorfer said.
He said scientists were also warning of the consequences of doing nothing.
"There is a moment when depletion of a species reaches a point of no return. If nothing is done and we reach that point then we are gambling on what a future without sharks and rays in our oceans will be like.
Cairns Fishing Adventures owner Carlo Ferrara said if numbers had fallen by 71 per cent, he knew "where the other 29 per cent were."
"It's extreme out here. The trend is going the other way round here," Mr Ferrara said.
After 15 years in the charter fishing game, Mr Ferrara said on Tuesday he returned with seven sharks to one Spanish mackerel and on another recent trip from 30 hooks, he hauled in only five fish.
Originally published as Fisho's shock at study revealing dramatic shark number decline