Carlos Duarte is director of the Oceans Institute at the University of Western Australia. This is an edited version of a piece he wrote for theconversation.com/au
THE article titled ‘‘The ocean is broken’’ by sailor Ivan Macfadyen, reporting the lack of fish and marine life and loads of garbage at sea in a sailing trip across the Pacific, and concluding that the ocean is broken, made waves on social media.
I understand his feelings, as I too have sailed many ocean miles as a researcher and a sailor.
He touches on overfishing and plastic pollution, which are real problems, as three-quarters of the ocean’s fish stocks have been depleted, some beyond recovery.
Fortunately, Australia’s fisheries are well managed and most of our fish stocks are healthy and strong.
The ocean also contains large amounts of plastic debris, which is harmful to marine life.
Yes there are plenty of problems in the ocean, but it is not yet broken. Depicting it so makes the problem seem boundless and deters society from engaging.
The conventional narrative extends from plastic pollution and overfishing to a litany of plagues including the proliferation of impacts associated with climate change, including ocean acidification, increase in marine pests and loss of habitat. Many of these are happening, but their severity and immediacy are sometimes exaggerated.
Let’s focus on Ian Macfadyen’s evidence: two snapshots of the Pacific, 10 years apart, suggesting a depletion of marine life and huge plastic pollution.
The ocean is a dynamic ecosystem, showing broad fluctuations over time in almost all properties. These fluctuations often deceive the casual observer, and high-quality data involving systematic long-term observations are necessary to detect real changes.
For instance, my co-workers and I conducted analyses of global changes in jellyfish to find that there is no basis to support the claim that they are increasing globally, one of the plagues of an allegedly broken ocean. Our results showed that jellyfish experience broad fluctuations of 20-year cycles that misled scientists into the perception that the most recent rising phase of this cycle (late 1990s to 2008) was an unprecedented event signalling the oceans being broken.
Our analysis showed that such fluctuations happened in the past, but very few scientists were watching and they lacked channels to share their results.
Likewise, we also now know that many changes that are portrayed as symptoms of a broken ocean – coral bleaching, outbreaks of populations such as the crown of thorns starfish or toxic algae – may represent symptoms of global oscillations, which we do not understand and where human drivers may play little or no role.
Separating natural process from human impacts is a daunting task, so we should not be too quick to jump to conclusions and blame humans for all changes we see in the ocean.
Australia has a model system to observe its oceans – the Integrated Marine Observation System – including tools to observe ocean properties with an emphasis on detecting change. It has set the benchmark with its scale, scope and thoroughness, and its data is freely available to all.
Its Achilles heel is likely to be its sustainability, against a landscape of increasing austerity of public expenditure.
But we cannot monitor the oceans just with buoys, gliders and satellites; we need to go to sea and take samples to verify what our instruments indicate.
Australia is grossly under-resourced for research at sea, with a capacity for seagoing research across 40,000kilometres of coast.
A milestone in addressing this problem will soon come to fruition with the launch of the R/V Investigator, the world’s most modern research vessel, an oceanic class 94-metre vessel being built in Singapore and soon to be sailing our oceans under CSIRO management.
Research capacities at sea allow us to build and verify models to grasp ocean dynamics. Soon after the tsunami of March 2011 that triggered the Fukushima accident in Japan, the National Oceanic and Atmospheric Administration (NOAA) published models that predicted how the huge patch of debris washed into the ocean by the retreating waves would take three years to travel across the ocean to strand, in March 2014, on beaches in California, Oregon and Washington.
Had Ian Macfadyen checked NOAA’s web page, he might have been prepared to meet the garbage patch he encountered.
The tsunami was not a human-driven impact, so we should moderate the guilt felt about so much debris. But it did provide brutal exposure to the reality of our lives – consuming and disposing of too many objects.
Likewise, do we ask ourselves how and where the fish we consume is captured? Does it come from a sustainable fishery? Do we enjoy seafood, but complain about the impacts of aquaculture?
Do we drive a 4WD car contributing carbon dioxide that will further acidify oceans? Did we vote to have our carbon tax removed because we say we can’t afford it?
Responsible consumers will not break the ocean; those who choose to ignore the consequences of their day-to-day decisions as consumers will. The arena where the struggle to spare the oceans from breaking is fought every day at our local shops.