Octopuses outsmart marine scientists

ct fish55 done WHATS UP? A sevengill shark (Notorynchus cepedianus) inspects the bait canister in front of the underwater video camera, with a young panga (Pterogymnus laniarius) shoal in the background. The underwater cameras run continuously for an hour at a time. The UCT reasearch team drops four cameras at a time about 250m apart. Photo: University of Cape Town/SAEON

Melanie Gosling

Environment Writer

WHEN UCT researchers lowered a specially-designed “baited” camera into False Bay to film life underwater, they had not reckoned on the wiliness of the bay’s octopuses.

Not only did one manage to open the bait canister and eat its fill of the pilchards inside, but some of its mates made off with bits of equipment.

UCT research assistant Lauren de Vos said yesterday: “We were flummoxed by how clever they are, smart enough to unclip the bait canister which is not easy, and we’ve had several pieces of equipment stolen. We’ve got it all on film.”

The underwater cameras, which run continuously for an hour at a time, have also captured curious seals peering at the bait canister, a great white gliding up above, and a seldom-seen St Joseph’s shark, or elephant fish.

“What we were really excited to see were the baby red steenbras, because that means we have not lost them from the system. Their population has been in decline, so it’s good to see them. And the red roman too. We were also surprised to see a tiny pipefish, unusual because we did not expect to pick up such small species – and a cormorant. We didn’t expect to see birds underwater.”

The project, funded by Save Our Seas Foundation, is headed by Colin Attwood, an associate professor at UCT, with De Vos and Albrecht Gotz from the SA Environmental Observation Network helping.

Albrecht and his doctoral student Anthony Bernard initiated the work a few years ago with underwater filming in the Tsitsikamma marine protected area, while De Vos did her masters in Stillbaai. The BRUVs – Baited Underwater Video Stations – were developed first in Australia and have been used on reefs there for 10 years.

“South Africa’s inshore fishery has been exploited for over 200 years and as a result many of the coastal species, from sharks and rays to bony fish, are in peril,” De Vos said.

“We need information about what’s in the water… to get an understanding of the conservation status of these species.

“We’re wanting to make this equipment cost-effective, so that it is realistic for fishery and marine protected area managers to use on their budgets,” she said.

The BRUV concept is simple: fish are attracted by the bait to move into the field of view of the video camera. It runs for an hour then is raised and footage analysed. The team drops four cameras at a time about 250m apart.

“We’re trying to develop an internationally standard method, so that we can compare data from oceans on a global level,” De Vos said.

“The False Bay project is to assess how many fish and shark species are in the bay, in what numbers, and to see the abundance of the commercially-exploited species.

“It’s also to provide educational videos. All our videos are online so it allows the public to join the research and see what we’re doing.”

l To see the videos and get more information visit http://saveourseas.com/projects/bruvs_false_bay


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