Humpback whales passing Coffs Coast up since hunting bans
WHALES migrating along the Coffs Coast may indicate bans on whaling have paid off for Australia's humpback population.
But a lack of data on most of the other 57 marine mammal species may be hindering efforts to ensure their ongoing survival.
A comprehensive review has found Australia's mammal extinction rate is the highest in the world.
Co-authored by Professor Peter Harrison, director of Southern Cross University's Marine Ecology Research Centre, the review found more than 10 per cent of the country's endemic mammal species have become extinct since European settlement.
A further 20 per cent of land mammals should now be recognised as threatened.
"The good news is Australia's humpback whale populations are increasing rapidly and are recovering as a result of the ban on commercial whaling," Professor Harrison said.
"The east coast population currently migrating along our coastline is likely to exceed 20,000 whales this year.
"Unfortunately, other great whales such as blue, fin, sei and sperm whales have not recovered from commercial whaling and remain threatened, and subantarctic fur seals and endemic Australian sea lions are also threatened.
"What the review also highlighted, however, was that for most marine mammal species it was impossible to assign a conservation status, because so little is known about their population size and trends, threats or ecology.
"There are some dolphin species found mainly in-shore, for example, that are facing significant threats to their environment from entanglement in fishing nets and coastal development, but we don't know enough about their population size and trends to focus management action where it is most needed."
Professor Harrison said this lack of data was severely limiting the ability to effectively manage or conserve Australia's marine mammals.
"We need a renewed focus on monitoring Australia's diverse marine mammal species to determine their conservation status and prevent catastrophic losses such as have occurred for terrestrial mammals," he added.