Man-made oil rigs, cables, pipelines used by Australian fur seals as feeding grounds: research

A new Australian research into the feeding behavior of local fur seals has determined the animals benefit from man-made structures such as pipelines and shipwrecks.

Often given bad publicity for their apparent environmental impact, artificial structures including cables and oil rigs have been found to act as a generous food source for seals.

The study, led by Melbourne's Deakin University in association with the University of Tasmania and University of California Santa Cruz, used GPS tracking and "seal-cam" video feeds which uncovered the animals' foraging routes.

The study found that seals were often attracted to artificial reefs, as they attract fish and other marine life, providing the seals with a happy hunting ground.

Professor John Arnould from Deakin University said the initial GPS data revealed the seals were following an unusually straight pattern, which led to uncovering the "artificial reef," or as it is known to local energy workers, the Basslink power pipeline.

"In one case we looked at the GPS track and it was a straight line, which made us think that the seal might be following fishing vessels," he told Fairfax Media on Thursday.

But the "seal-cam" vision showed that fur seals followed pipelines, cables and underwater wrecks, as they attract fish and other seal food, such as octopus and squid.

Arnould said the seals stayed almost exclusively within 100 meters of the underwater infrastructure.

"Structures can influence currents and therefore nutrient transport, so even if seals aren't always feeding on the pipeline, the pipeline is influencing where they forage," he said.

"The amount of fish around this structure was unbelievable."

Arnould told the Australian Broadcasting Corporation that underwater structures not only provide ample food for fur seals, but they could also play a vital role in improving the recovery rate of the animals, which were hunted almost to extinction throughout Australia during the 18th and early 19th centuries.

"Fur seal populations are increasing at just 2 percent a year and still sit at population levels below 60 percent of what they were before the commercial sealing era," he said.

"Man-made structures can provide a range of benefits, from predator avoidance, thermoregulation, and breeding sites, to acting as important foraging areas."

The research will be published in the next edition of scientific journal PLOS One. Endi