Scientists call for protection of Australia’s subtropic seas

Leading scientists and marine managers have called for a greater national effort to protect vital 1000-kilometre stretches in the middle of Australia's eastern and western coastlines.

In a major statement entitled The Coffs Harbour Subtropical Reefs Declaration, they urge increased focus and better management for reefs south of the Great Barrier Reef and WA tropical coral zone, explaining that these more southerly areas are expected to become critical refuges for northern tropical marine life under global warming.

The declaration follows a workshop by researchers and marine managers at the National Marine Science Centre in Coffs Harbour in September which concluded that the subtropics will play a key role in safeguarding Australia's tropical marine life as ocean warming drives it southwards – especially if northern coral reefs die off, as some scientists fear.

The Coffs Harbour Declaration was made by a new expert group called the Sustainable Subtropical Reefs Alliance (SuSRA), which has been established to advocate for greater ocean research and conservation on coastal areas between Sydney and Bundaberg on the east coast and Perth and Shark Bay on the west coast.

Among its signatories are scientists from five of Australia's east coast universities – Southern Cross University, Tasmania, Sydney, Queensland and James Cook, marine park managers, and the CSIRO (Queensland and Western Australia).

Professor Peter Harrison, director of Southern Cross University’s Marine Ecology Research Centre, said the region from south-east Queensland to the Solitary Islands Marine Park in NSW, was a biodiversity hotspot.

“The important thing about this region is there is a unique overlap of tropical species at the southern limits of their distribution, some sub-tropical species that are found only in this region, and some cooler water temperate species which are at their northern limit,” Professor Harrison said.

“Increasing sea temperatures, ocean acidification and the rapidly expanding human population and associated development of these coastal environments will have a significant impact on marine life in this region.”

The Coffs Harbour Declaration states that the eastern and western coasts of Australia are amongst the longest latitudinal tracts of subtropical coastal marine habitat in the world, encompassing beaches, rocky foreshores, offshore islands, shoals and reefs.

Changes in fish and coral distribution now being observed by scientists have made it imperative to re-evaluate conservation plans for the central coasts and strengthen them where necessary, it states.

The declaration highlights seven priorities for improving the management of Australia subtropical marine environment:

1. Integrate science and resource management across federal, state and local agencies to ensure better planning and management of subtropical marine areas;
2. Study how social, economic and political factors affect the management of coastal resources and the services they in turn provide to coastal communities;
3. Understand the existing ecology and map existing coastal habitat;
4. Evaluate threats to marine resources from land-based activities, benchmark their past and current status and monitor changes;
5. Determine pathways for tropical marine ‘invaders' moving into the subtropics due to climate change, and the impact on local species;
6. Determine which sites (refugia) are critical to preserving subtropical marine fish, corals and other species in the event of profound environmental change;
7. Investigate natural variability of existing subtropical marine areas (so as to detect unusual changes).

The declaration says: “We call upon practitioners, managers, researchers, funding bodies and governments to recognise that these priority areas require urgent attention and investment to enable effective and efficient decision making for the future of subtropical reefs.”

The full text of the Coffs Harbour Declaration is available at: www.coralcoe.org.au

Photo: Professor Peter Harrison.