A collaborative research project between the University of Queensland (UQ) and Australia's CSIRO is investigating the biology and ecology of a large, tuna-like predator, the wahoo.
PhD student Mitchell Zischke commenced this full-time project in September 2008, and will spend the next 3 years using various techniques to address the aims of this project. The project will be the first of its kind in Australia, will use many novel techniques for the species and will add valuable information to the currently limited knowledge for wahoo throughout the world.
The specific aims of this rigorous scientific research project are to:
Investigate the biology of wahoo off eastern Australia (e.g. growth, spawning, diet).
Determine the population structure of wahoo both along the east-coast, and between eastern and western Australia.
Estimate the catch and effort for wahoo from all fishing sectors.
Assess the sustainability of current and future fishing effort on wahoo populations and the pelagic ecosystem.
Significance and justification
Commercial fisheries are a major source of economic productivity from our oceans, with the Eastern Tuna and Billfish Fishery (ETBF) being one of Australia's most valuable fisheries. In addition, ocean resources are used for many recreational activities and provide social and economic benefits to the community. Accurate data on species biology, population dynamics, ecosystem relationships and fishing pressure are needed to facilitate sustainable fisheries management.
Current biological and ecological data for wahoo are limited primarily to the Atlantic Ocean. Often many of these parameters (e.g. growth rates and diet) will vary considerably with geographic location. Therefore, this project will provide the first detailed biological and ecological investigation for wahoo in the region, and significantly contribute to the global scientific knowledge for the species. In addition, commercial catch data for Australian fisheries will be collated, and previously unknown recreational catch and effort for the species will be quantified. Finally, this project will attempt the first population assessment for wahoo, as well as provide the first specific ecosystem simulation involving the species. This suite of data will help ensure the long-term sustainability of populations and the integrity of the pelagic ecosystem in which wahoo play a significant role as an apex predator.
Wahoo tagging - Have you recovered a tag?
In August 2009, approximately 150 wahoo were tagged and released in the Coral Sea. Standard yellow plastic dart tags were inserted near the second dorsal fin of fish, and the fish was injected with a fluorescent dye. While this dye is not harmful to humans, it helps us validate the age of wahoo. Therefore if these tagged fish are recaptured, it is essential that you record the tag details, and retain (and freeze) the head of the recaptured fish. You can then contact me to report the recapture and claim the reward that is on offer.
