Wednesday 26 October 2005

Aggregation fishing is a global threat to healthy coral reef ecosystems and food security in the tropics, according to a local fisheries expert.

Great Barrier Reef Marine Mark Authority (GBRMPA) Fisheries Project Manager Martin Russell said globally there was an urgent need to address fishing pressure on places where tropical fish species gather at specific times to spawn.

“Many coral reefs around the world are being seriously affected by intense fishing pressure, and increasing interest in focusing fishing on reef fish spawning aggregations is concerning,” he said.

Mr Russell said this trend was first noticed in the tropical western Atlantic, later spreading to the Indo-Pacific.

“Reef fish must complete their life cycle if there are to be fish for the future, therefore spawning aggregations are highly important to fish and any fishery based on that fish.”

Mr Russell said spawning aggregations couldn’t withstand uncontrolled fishing.

“The increased abundance of fish in localised areas at predictable times makes spawning aggregations particularly vulnerable to overexploitation by fishing.”

Spawning aggregations of about 50 species of fish are reported in the Great Barrier Reef Marine Park to date. More than 80 other species of fish are reported to aggregate to spawn elsewhere within their geographical range.

Mr Russell said there was no simple solution to protecting these spawning sites but some positive steps had been taken.

“In the Great Barrier Reef Marine Park the concern about fishing of spawning aggregations has been greatly alleviated through proactive management by the GBRMPA and Queensland Government,” he said.

“The Queensland Government has introduced size limits and spawning closures, and GBRMPA now has 33 per cent protection of the Great Barrier Reef Marine Park.”

He said including the spawning sites in the design of reserve networks would help to maintain sustainability and resilience of fish stocks. Sites are influenced by seasons, lunar phases and temperature, and fish usually aggregate at places with specific characteristics.