Aquaculture for all

Spanner Crab Catch May Increase in Cooler Waters

Crustaceans Sustainability Economics +5 more

AUSTRALIA - New research as found that fishermen can catch more spanner crab in cooler waters. Previous studies thought catch rates were connected to warmer temperatures or had no relationship at all.

Lucy Towers thumbnail

PhD research David Spencer from Griffith University found that upwelling events that cause the water to become cooler could enhance catchability of spanner crabs.

The work has seen Mr Spencer awarded the prestigious Peter Holloway Oceanography Prize from the Australian Marine Sciences Association.

Mr Spencer went out offshore the Gold Coast between May and November last year, working with local spanner crab fishermen Richard and Mondo to investigate whether oceanographic processes play a role in variable day-to-day catches.

"Essentially what I found was that spanner crab appeared to prefer cooler temperatures but it was interesting because two previous studies found different results - one found they liked warmer temperatures and another that there was no relationship," he said.

"I took my research a bit further to find out what was happening using 2011-2014 data from a larger number of fishing vessels."

The spanner crab fishing season closes at the end of each year while they are spawning.

"The most interesting conclusion is that short-term fluctuations tend to have the greatest influence when considering the effect temperature has on spanner crab catches," he said.

"It will certainly help fishermen if they're running low on their quota. Sometimes it's best to wait for certain periods of the year and quota management is a big thing for local fishermen.

"Fishermen would greatly benefit from knowing which days/periods of the year to not go out too, because if there are warm temperatures expected, causing a drop in catch, then they may wait for a change in temperature.

"This will help them plan a highly efficient fishing week/month with respect to both time and cost of running the boat."