The Coral Sea of the southwestern Pacific Ocean is located off the northeastern coast of Australia, bounded by Queen Island to the west, Vanuatu and New Caledonia to the east, and the Solomon Islands to the north. It is about 1,400 miles (2,250 km) north–south and 1,500 miles east–west and covers an area of 1,849,800 square miles (4,791,000 square km). To the south it merges with the Tasman Sea. The South Solomon Trench reaches depths of 24,002 feet (7,316 m), and the New Hebrides Trench plunges to 25,134 feet.
Located off the east coast of Queensland, in the western part of the Coral Sea, the Great Barrier Reef ecosystem is one of the world’s seven natural wonders and a prized UNESCO World Heritage Area. At 344,400 square km (the size of Japan), it is the largest coral reef system and the biggest living structure on the planet, and millions of people travel across the world every year to marvel at this treasure trove of marine life. It is home to 1,600+ species of fish, 133 sharks and rays, 30 varieties of whales and dolphins, and six of seven marine turtle species.
The Reef is under threat
The Reef has a global reputation for its crystal clear waters, kaleidoscopic corals, and more than 900 picturesque islands. This network of marine sanctuaries holds unparalleled ecological importance, serving as a haven for thousands of plants and animals. It creates jobs for 60,000 people and contributes $6.4bn annually to the local economy. But it is under threat from climate change, coral bleaching (in 2024 it suffered the fifth and worst event in 8 years), pollution and overfishing.
The Australian Marine Conservation Society (AMCS) is the only national charity dedicated exclusively to protecting ocean wildlife and its homes. The key focus of AMCS is to create large marine national parks (marine sanctuaries) and sustainable fisheries and to protect and recover threatened ocean wildlife, such as sharks, seals and whales. AMCS also works to protect Australia’s coasts from inappropriate development, including along the Great Barrier Reef. In recent years it has concentrated on the main threats to the Reef described above.
Turtle’s eye view
Take a turtle’s eye view of the reef with The World Wildlife Fund (WWF) Australia, who also give considerable support to its conservation. In 2016, they purchased and retired two commercial gill-net fishing licences to help create a haven for threatened marine wildlife. They later purchased two more licences, establishing a 100,000 square km safe haven for dugongs, dolphins and turtles in the northern Great Barrier Reef.
In 2023, the Australian and Queensland governments announced their commitment to permanently phase out commercial gill net fishing from the Great Barrier Reef World Heritage Area by June 2027.
In 2019, WWF Australia issued a state of plastics report detailing how each state was coping with the threat of plastic pollution in its oceans.
Coral bleaching
One of the greatest challenges is gradual coral bleaching. Solutions developed in Australia are applicable to other coral reefs worldwide. Let us first understand what coral bleaching is and the results of research into the scope of the problem by James Cook University. Before we review the solutions that are just beginning to show some success in halting and reversing the bleaching, we need to take a closer look at the wide diversity of marine life that inhabits this fragile paradise.
Coral restoration techniques now being applied are:
- Underwater coral nurseries for propagation of coral fragments to be replanted in damaged areas. By early 2025 more than 110,000 corals had been planted over 30 sites with 85% success. This has been a joint venture for scientists and tourists.
- Coral in vitro fertilisation (IVF) involves managing coral larvae and planting them in suitable environments to enhance their survival. This option shows promise in restoring reefs damaged by cyclones and severe storms.
- Stress testing experiments to understand how corals respond to stress, such as rising water temperatures. Coral fragments are heated in a controlled environment to study their resilience and adaptability.
Overfishing is a worldwide problem
It is unreasonable to expect people living close to any sea apparently abundant with stocks of a nutritious and healthy source of food not to take advantage of it to feed their families and create business opportunities. In the 1960s, the average person ate 9.9 kg of fish every year. By the 2020s, this has risen to over 22 kg, and the population is rising. The demand for seafood could double by 2050, and despite the imposition of quotas for threatened species, 38% of worldwide fishing grounds are still overfished, including 17.5% of Australian fishing grounds.
In Australia, the most threatened species are school sharks, orange roughy, bluefin tuna, coral trout and red throat emperor.
Commercial fishing is worth an average A$200m per annum but is controlled to ensure it is sustainable. All commercial fishing vessels are fitted with a satellite tracking system and specific restrictions applied to defined zoning areas. Recreational fishing is allowed but also with detailed regulations, including the number of lines and hooks per person.
Coral harvesting
Believe it or not, harvesting of coral for personal aquariums is still a thriving business despite all the other threats to the Reef. The AMCS wants this to be banned completely, and the EU and UK banned import of corals from Queensland in 2022. There is a debate that the business should adapt to aquaculture to grow appropriate species of coral in tanks.
Do you still want to visit the Reef?
If so, here are some tips on choosing the best option for you and your family. If you’re staying in Cairns, I suggest you combine it with a trip to the Kuranda resort high above the rain forest. You can travel there by steam train or sky rail over the treetops.
What have I missed?
Only the most important single element of the oceans – the water itself. Our oceans are interconnected to form a single, powerful engine driven by sunlight and affected by changes in water temperature, salinity, gravity and tectonic plate movements. From the ocean floor to tropical coral reefs, estuaries and Arctic ice floes, it redistributes energy from the equator to the poles, affecting the global climate. It plays a vital part in supporting all marine life, from tiny plankton to massive whales. This is the science of oceanography, which will be my topic for a future article.
