A Parks Australia-led voyage to monitor island health in the Coral Sea Marine Park has uncovered a surprising array of marine species and recovered 10 cubic metres of marine debris.

The voyage to assess islands, sea bird populations and diversity, vegetation, invasive species and marine debris in the marine park was made in June by a team from Parks Australia, Queensland Parks and Wildlife, Tangaroa Blue and volunteer botanists.

These marine park expeditions help build our understanding of island health in this remote but incredibly rich and diverse part of Australia. They include assessments of sea bird species and their breeding levels, vegetation, pest species and marine debris in the region.

At over 900,000 square kilometres—or three times the size of the adjacent Great Barrier Reef Marine Park—the Coral Sea Marine Park is one of the largest marine parks in the world. We work together with other partners within and beyond government to understand and protect this pristine environment.

Marine debris was collected for analysis to understand the type of debris accumulating on these islands, the level of build-up over time and where the debris is from.

Around 10 cubic metres of marine debris was collected which included 240 meters of plastic bottles, placed end to end, for recycling.

The marine debris recovered is consistent with previous voyages, where everything from plastic bottles and fishing nets to thongs and shipping ropes has been collected.

Highlights during the voyage included some pleasant discoveries:

• 10 per cent of the global population of endangered New Caledonia fairy terns nesting at one island
• A globally significant nesting area for red tailed tropic birds (more than 690 breeding pairs)
• Globally significant nesting populations of sooty terns (one island with more than 40, 000 nesting pairs of birds)
• No evidence of invasive rodents at any of the islands.

These significant outcomes demonstrate the importance of remote islands as a wild and relatively unimpacted refuge for bird colonies—and the need for ongoing monitoring of their health and continued prevention of the potentially devastating effects of invasive species.

The data will be used to help better understand the dynamic nature of these special places - including climate change effects and erosion on islands.