Our tropical sea treasures are under threat. Despite increasing pressures from the oil and gas industry and some kinds of fishing, less than 7% of these regions waters are fully protected in marine sanctuaries.
Oil and gas
Rapid expansion of the oil and gas industry across the Ningaloo–Pilbara, Kimberley, Top End and Gulf pose a major threat to this unique marine environment.
Petroleum exploration and drilling not only disturbs underwater habitats and interrupts whale migration routes, it has caused disastrous oil spills such as the 2009 Montara incident, which spewed millions of litres of oil into the Timor Sea over a ten week period. The rapid expansion of the industry across these regions increases the risk of another spill, potentially even more damaging.
In the Top End a new petroleum lease was released in 2011 directly adjoining the Coburg Peninsula marine protected area, threatening sensitive marine life safeguarded by the region’s only underwater sanctuary.
In the Ningaloo–Pilbara and Kimberley, new oil and gas leases in the Carnarvon and Browse Basin pose real dangers to critical marine habitats including the Rowley Shoals, Ningaloo Reef and Shark Bay. Only recently, drilling started in deep water just off World Heritage-listed Ningaloo Reef.
The 180,000km2 of sea floor released for petroleum exploration in 2011 which filled gaps between existing leases is particularly concerning as it will increase the risks and impacts associated with this industry. More sensitive areas were released to the oil and gas industry in 2012.
There are many ways to catch a fish, but some kinds of fishing impact upon the marine environment more than others.
Each year, thousands of kilometres of sea floor across northern Australia are trawled to catch a range of prawns, fish and shellfish.
Trawlers catch prawns and other fish by dragging weighted nets across the seabed, but in doing so they can damage sea floor habitats like sea grass meadows and sponge gardens.
Trawlers also accidentally catch (or ‘by-catch’) non-edible fish and other marine life that swim along, or attach to, the sea floor. By-catch is often thrown overboard as waste.
The welcome introduction of Turtle Exclusion Devices has reduced by-catch of sea turtles by 98%, however vulnerable sawsharks, dwarf lionfish, wobbegongs, sea snakes and porcupine rays are still being caught by trawlers in the Top End and Gulf.
In the Pilbara, there are efforts to reduce the by-catch of dolphins however, there is still a serious problem while by-catch reduction devices have reduced the amount of overall by-catch, uncertainty remains over the survival of wildlife released from the devices.
The need to reduce sea floor damage and further reduce by-catch impacts, remain serious sustainability challenges for the trawling industry across the Ningaloo–Pilbara, Kimberley, Top End and Gulf.
Australia’s tropical seas are home to many rare and endangered shark species but existing fishing regulations may be insufficient to protect them.
Sharks need our protection because they play a critical role as a top predator in our oceans, keeping populations of other marine life in check. Yet shark numbers continue to decline dramatically worldwide.
While developing countries like Palau, the Maldives and Honduras have declared large marine sanctuaries to protect sharks in their tropical waters, Australia needs to do more to ensure a healthy future for our magnificent tropical sharks.