Ocean conservation is not simply environmentalism, it’s medicine.
Australians have always had a special relationship with the ocean. The ocean is central to Australia’s cultural, environmental, economic and social wellbeing.
For our First Nations people, it has long been a source of food, culture, and spirituality, with people from saltwater clans having totemic relationships with different sea creatures. We boast the world’s largest coral reef system and the world’s largest fringing reef.
Increasingly, the rest of the world is waking up to what ordinary Australians have long known: the ocean matters.
David Attenborough recently celebrated his 99th birthday by releasing a new (and captivating) documentary, Ocean. This film was released ahead of the third ever UN Ocean Conference taking place this month, which aims to “support further and urgent action to conserve and sustainably use the oceans, seas and marine resources for sustainable development”.
As the anthropogenic devastation of our oceans edges ever closer towards the point-of-no-return, the public and scientific momentum to steer the course towards a different future for humanity has never been stronger.
So there has never been a better time to discuss the intrinsic relationship between the ocean and human health.
The ocean is a vital regulator of the world’s climate. When phytoplankton die, some of the carbon they absorb through photosynthesis sinks to the ocean depths, where it is sequestered from the atmosphere. This process makes the ocean the earth’s largest carbon sink.
In fact, oceans have absorbed approximately 40% of all the carbon dioxide humans have put into the atmosphere since the Industrial Revolution.
Some climate models project that warming temperatures will result in fewer phytoplankton. Climate change is the single biggest health threat facing humanity.
Microplastics in our oceans are a significant cause for concern.
Globally, about 400 million tonnes of plastic waste is produced each year, of which up to 10 million ends up in our oceans. Plastic waste comprises 80% of all marine pollution and by 2050, plastic will likely outweigh all fish in the sea. After entering the ocean, plastic can undergo degradation into smaller particles called microplastics.
Although acquisition occurs from a variety of sources, including bottled and tap water (water is the predominant source of ingestion), meat, and even the air, the amount of microplastics present in seafood is alarming.
A recent American study found that 99% of samples of fish contained microplastics. Microplastics have been found in human tissues as diverse as the placenta, brain, and hip and knee joints.
Although this field of research is still an evolving space and so the precise health consequences are not yet fully understood, microplastics have been linked to various cancers, autoimmune disorders, heart disease, fertility problems, and neurodegenerative diseases.
There has been much discourse in the health sector over the past few years about green spaces and “green scripts”, but the notions of blue spaces (bodies of water including oceans, lakes, and rivers) and “blue scripts” are slowly gaining traction.
A systematic review and meta-analysis found that being in more contact with blue space was significantly associated with higher levels of restoration (markers of which include stress, anxiety, depressed mood and psychological wellbeing).
And being able to experience the biodiversity of the ocean is important.
A key study done on the relationship between scuba diving and mental health found positive effects, particularly among subjects on regular medication for a chronic or psychiatric illness. One recent study found that scuba diving was a transformative experience for people with physical impairments, raising the potential for scuba diving as a prospective rehabilitation intervention. A pilot study of cancer patients undertaking blue prescriptions, which involved beach walking, sea swimming, and snorkelling, found improvements in mental health and wellbeing.
Any ocean lover who has ever visited one of Australia’s various spectacular reefs, or been swimming with sea lions, or whale sharks, or whales, will be wholly unsurprised by these findings. Awe-inspiring experiences like these can not simply lift one’s spirits but change the way people see the world.
A healthy aquatic ecosystem is important for food security and household income.
More than three billion people in the world rely on wild-caught and farmed seafood as a significant source of animal protein. At present, a staggering 85% of marine fish stocks are either fully exploited or overfished. Research has found that investment into marine-protected areas mostly increases both fisherfolk’s income and access to nutrient-rich aquatic food.
The marine conservation/human diet relationship is poorly researched, but one study from the Philippines found an association between increased dietary fish secondary to marine conservation and a decrease in stunted growth in children. Aquatic foods have the potential to play a meaningful role in global food insecurity and malnutrition, if the countries that these foods are sourced from have equitable access to them, described so perfectly by Attenborough as “modern colonialism at sea”.
Like the natural environment on land, our oceans hold the key to so many exciting medical discoveries.
Recent research found that antimicrobial proteins isolated from oyster haemolymph can kill certain bacteria responsible for a variety of infections, which is a significant finding in a time of widespread antimicrobial resistance.
Medical discoveries from the ocean have already been in use for decades, however. Intrathecal analgesic ziconotide originated from the venom of the marine cone snail, while ara-A, an antiviral drug, and ara-C, the first marine-derived anticancer agent, came from marine sponges on Caribbean reefs. The same reefs are predicted by UNESCO to disappear at the end of this century under a “business as usual” emissions scenario.
“Thirty by 30” is a worldwide initiative for governments to designate 30% of Earth’s land and oceans as protected areas by 2030. It was agreed at the 2022 COP15 meeting of the UN Convention on Biological Diversity and became a target of the Kunming-Montreal Global Biodiversity Framework. The Australian Government adopted this target in 2024. The clock is loudly ticking.
But it’s not just politicians and conservationists who have a role to play here.
As doctors, we can advocate for ocean health to be integrated into public health frameworks. We can use our authority as trusted health professionals to advocate for meaningful action on marine pollution. We can advocate for sustainable seafood systems. We can recommend “blue prescriptions”.
As I hope I have clearly shown through this article, ocean conservation is not simply environmentalism, it’s medicine.
Dr Brooke Ah Shay is a rural generalist working in Yarrabah, far north Queensland, and a senior lecturer at James Cook University.
