From COSMOS magazine:
First footage of creatures in Perth Canyon
Tuesday, 8 June 2010
by Maria Thuesen Bleeg
SYDNEY: Scientists have captured on video some of the creatures that dwell within the enormous Perth Canyon, providing a new glimpse into the deep-sea ecosystem off the coast of Western Australia.
“We didn’t know what to expect because we haven’t been able to look at these fish assemblages before. I was surprised to see pink snappers at 250 meters, because they are reported to go only 200 meters,” said Jessica Meeuwig, a marine biologist from the University of Western Australia.
Scientists placed cameras at 65 stations around Perth Canyon in the Indian Ocean in mid-March 2010, and both deepwater sharks and rocket squids were caught on tape in the canyon, which Meeuwig calls an “oasis of richness”.
Many species are unique to Australia
“Many of the species we saw, like the bight redfish and a sawtail catshark are only found in Australia. We know that in the shallow waters, many of the fish we see are unique to Australia and potentially, this pattern is holding in the deeper areas as well,” said Meeuwig.
The bight redfish has been identified as one of the vulnerable 8 fish species in Western Australia because it is vulnerable to overexploitation, but despite the footage researches still don’t have enough samples to get an idea of the remaining number of bight redfish.
Perth Canyon was carved millions of years ago by the Swan River but is now submerged deep beneath the waves, 22 kilometres west of Rottnest Island. Scientists placed cameras between 100 and 500 metres beneath the surface, filming underwater life there for the first time.
Perth Canyon: 1.5 km deep
“Canyons drop off so quickly, and you can learn a lot about how the abundance and size of marine life changes with depth,” said Meeuwig, who compares the footage with going into a forest for the first time, and seeing birds you’ve never seen before.
The Perth Canyon is about 1.5 kilometres deep and 15 kilometres wide. It is Australia’s largest submarine canyon and equal in size to the Grand Canyon in Arizona, USA.
It is also one of only two places in Australia that the endangered blue whale comes to feed.
Fish will head south with climate change
“Australia is lucky to have a relatively healthy marine environment, but the human population is growing and the climate is changing so a lot of things could happen,” said Meeuwig.
One of the predictions of climate change and ocean warming is that fish will not only head south to cooler waters, but will also head deeper. In this way, having an understanding of the current wildlife will help scientists to recognise change in the future:
Scientists will continue dropping cameras around Western Australia to get a better understanding of the marine life.
More protection needed
Less than 1% of Western Australia’s oceans has any protection in place, and the video footage could support decisions about where to place large marine sanctuaries to protect species and support recovery from overfishing.
Still, there is a lot of scientific work left for the marine biologists given the general lack of data:
“We have very little information about the ocean, despite its importance and how heavily we use it. We will continue deploying our cameras to ensure we have a baseline understanding of this special place,” said Meeuwig.
Ocean gliders uncover underwater ‘Rivers’ off of Perth, Australia: here.
July 2010: Exploration of the seas around Ullapool in Scotland is underway to confirm the presence of some of the country’s most important marine wildlife features. A team of marine biologists from Herriot Watt University’s School of Life Sciences and Scottish Natural Heritage (SNH) will be charting the quantity, quality and distribution of habitats and species of greatest conservation importance known as Priority Marine Features (PMFs): here.