New research shows that some fish species in Western Australia's (WA) Ningaloo Marine Park spend most of their time close to home, staying on the reef rather than travelling significant distances, as was previously thought.
Since November 2007, scientists from Australia's Commonwealth Scientific and Industrial Research Organisation's (CSIRO) Wealth from Oceans National Research Flagship have tagged over 300 fish in the Ningaloo area off WA's North West Cape as part of a Western Australia Marine Science Institution (WAMSI) project.
CSIRO's Dr Richard Pillans told the 8th Indo-Pacific Fish Conference held recently in Perth that around 40 percent of tagged spangled emperor (a sport fish also known as nor-west snapper) remained within hundreds of metres of where they were originally captured.
"This is really exciting information as it provides evidence of a resident population," Dr Pillans said. "Data from the tags also showed that highly mobile species like gold spot trevally and grey reef sharks spent the majority of time within just a few kilometres of where they were tagged."
The research aims to identify what influences the movement patterns and habitat use of fishes in the park, which encompasses the majority of Ningaloo Reef, the largest fringing reef in Australia.
The new data on the long-term movement patterns of sharks and other fish in the park will have important implications for future management decisions on the size and placement of sanctuary zones.
Currently, 34 percent of the park is reserved as sanctuaries designed to protect marine animals and their habitat from human disturbance.
To better understand fish movement patterns and habitat use within the park, the Ningaloo Reef Ecosystem Tracking Array (NRETA) was established in 2007 as part of the integrated marine observing system's Australian acoustic tracking and monitoring system. NRETA consists of 104 acoustic receivers along the Ningaloo coastline and is Australia's largest array of acoustic receivers.
Fish tagged with internal ultrasonic tags are then able to be accurately tracked around the study site. Over time, the information collected builds up a picture of the individual's movement patterns.
Project leader, CSIRO's Dr Russ Babcock, said many other previously unknown aspects of the lives of fish on Ningaloo, such as where and when different species spawn, are being revealed.
"We're working on gathering information that will inform management to assist protection of individual species and groups of species," Dr Babcock said. "At the end of the study, we will be able to give the WA Department of Environment & Conservation a really good idea how fish and sharks use the marine park."
