Mystery giant grouper deaths

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A three-year, $930,000 research programme is under way to try to discover what is behind a recent spate of deaths of Giant groupers, Epinephelus lanceolatus, around Queensland, Australia.

More than 80 of the giant fish have been found dead or dying on local beaches in the past two years and post mortem investigations have discovered that many of the fish were suffering from bacterial septicaemia and meningitis, caused by the bacteria Streptococcus agalactiae.

The new research will look at how groupers become infected with the bacteria and how it is spread between fish as well as the development of diagnostic tests to detect the disease in fish and link it to deaths in both wild fish populations and aquaculture.

The Giant grouper is a protected species in Australia, and considered iconic in Queensland where it helps attract many dive tourists to the area. It is hoped the research can help prevent further losses.

Also known as the Banded rockcod, it is the largest reef dwelling bony fish in the world. Growing to over 3m/10ft and weighing in at around 400kg/880lb, they feed on spiny lobsters, crabs, fish and juvenile marine turtles.

They are protogynous hermaphrodites starting life as females with larger fish becoming males as they mature. Epinephelus lanceolatus is listed as 'vulnerable' on the IUCN red list.