RESEARCH at Ningaloo Reef has found fish species targeted by fishermen, such as trevally and north west snapper, as well as some non-target species tend to be larger and more abundant if they reside in sanctuary zones in the region.
The research, which was collated in 2006 and 2007 across four separate locations, provides strong evidence to suggest protected areas can increase the abundance of overall fish assemblages in the ocean.
Oceanwise Australia director and lead author Dr Ben Fitzpatrick says the study found fish in protected fish assemblages were more abundant than in areas that were regularly fished.
“We found that both target species and some non-target species can benefit from sanctuary zones,” Dr Fitzpatrick says.
“Protected locations provide more opportunities for more individuals to participate in an ecosystem.
“Much like a city provides for more jobs than a small town, an intact ecosystem provides more opportunities for greater numbers of individuals.”
Dr Fitzpatrick says throughout the study, which involved scientists from The UWA Oceans Institute, Curtin University and CSIRO, the number of each species of fish remained similar.
However, fish abundance and biomass seemed to be greater in sanctuary zones, which have been in place since 1987, he says.
“It seems more abundant and larger target fish facilitate more opportunities for other fish in the ecosystem,” he says.
Leftover meal a smorgasbord for smaller fish
“The target fish will leave scraps of food for smaller scavengers, they also need more cleaning from cleaner wrasse, they also stir up the rubble and sand on the seafloor meaning that more food is uncovered for smaller fish.
“Finally, they eat more hence they poo more, again increasing the resources available to the rest of the ecosystem.”
Dr Fitzpatrick says they collected the data using stereo baited remote video cameras.
“These camera systems attract the fish in the immediate area, which can subsequently be identified and measured from the footage back in the computer lab,” he says.
“We recorded all fish attracted to the baited video cameras—at least a few hundred different species—of these just a small percentage of them are targeted by fishers.
“These included north west snapper [Lethrinus nebulosus], trevally [Carangidae] and cod [Serranidae].”
Dr Fitzpatrick says the findings can help marine life researchers gain a better understanding of how coral reef fish ecosystems work.
“It can be used to provide information for managing fisheries resources and the design of marine protected areas to achieve conservation of marine ecosystems,” he says.