Are the oceans really dying?
- Ivo Vegter
- 16 Feb 2015 11:27 (South Africa)
It may not surprise you to learn that I have a lot of conversations about the supposedly disastrous impact on the planet of human civilisation. As a defender of said civilisation, I’m often at the receiving end of disdain and even hatred from those who believe humans are a plague ravaging the planet.
Often, once the most obvious myths, exaggerations and misconceptions are exhausted, my interlocutor retreats to the water. That is, they point at the sea as the final proof of humanity’s depravity and guilt. After all, what is more obvious than the collapse of fish stocks, and the fact that this time next year, the ocean will be vinegar?
It is a matter of record, if you’re a regular reader of my columns, that exaggeration is common among green-minded people. There are good reasons for this. People tend to believe environmentalists because they appear well-intended, despite the fact that green groups have a marketing job to do. Their careers, like those of any company staffer, depend on meeting revenue targets.
Environmentalists are not immune to using hyperbole, lies of omission, red herrings, and appeals to sentiment, fear, guilt, reward or empathy. These are the exact same techniques that a corporate spin doctor would use in advertising. True, many environmentalists are motivated by a genuine belief that they have science on their side, and that they are doing something good for society (or, if they are more misanthropic, for the earth). However, this is also true for many corporate employees.
Few people knowingly spend their lives doing what they consider to be evil, but motives and good intentions don’t matter half as much as facts and consequences.
If green exaggeration is so common, what about the claims about places most people don’t actually go, like the ocean? Are they real concerns, or are they mere bogeymen to scare us onto the straight and narrow path of green religion?
It is easy to believe that the crises are real. After all, the sea, unlike land, is for the most part not owned by anyone. That means that it is subject to the tragedy of the commons. Because everyone has to look after it, nobody does.
I’ve cited the decline of major fisheries myself as an example of a serious environmental issue that needs to be addressed. (Of course, I believe that the best solution is to establish and trade property rights in fish stocks, and that individual transferrable quotas go some way towards doing so. Disconcertingly, environmentalists agree.)
But, if the media are to be believed, things are much worse than having to order tuna-friendly dolphin at the sushi bar.
No lesser authority than the New York Times warned that “ocean life faces mass extinction”.
All this sounds terribly serious. However, a bit further into the story, we discover this: “Compared with the continents, the oceans are mostly intact, still wild enough to bounce back to ecological health… Until now, the seas largely have been spared the carnage visited on terrestrial species.”
Well, are the oceans on the brink of a mass extinction event, or are they mostly intact because they’ve been spared carnage? Pick one.
Another typical newspaper account, from the Seattle Times, read: “Ocean acidification, the lesser-known twin of climate change, threatens to scramble marine life on a scale almost too big to fathom.”
The idea of humanity’s disastrous effects on marine ecosystems is far from new. In one of the most cited papers in the field, Jackson (2001), one can find this alarming line: “Synergistic effects of habitat destruction, overfishing, introduced species, warming, acidification, toxins, and massive runoff of nutrients are transforming once complex ecosystems like coral reefs and kelp forests into monotonous level bottoms, transforming clear and productive coastal seas into anoxic dead zones, and transforming complex food webs topped by big animals into simplified, microbially dominated ecosystems with boom and bust cycles of toxic dinoflagellate blooms, jellyfish, and disease.”
Ouch. If true.
The panic of popular science writers (and some scientists) notwithstanding, it appears many of the scares related to the oceans have been overblown. That is the finding of a recent study entitled “Reconsidering Ocean Calamities”, by eight scientists led by Carlos Duarte, published in the journal BioScience.
“News headlines convey the notion that the ocean is in [sic] imminent risk of ecological collapse,” they write. However, upon testing the accounts of calamities, it turns out they sometimes lack robust evidence. The authors also point the finger at marine research scientists themselves, who they say “may not have remained sufficiently skeptical”.
The authors consider calamities as events that satisfy three criteria: whether they can be attributed to human activity, whether they have spread to a global scale, and whether they cause severe ecosystem damage.
“An analysis of some of the calamities reported in doom and gloom media accounts shows some – at times, severe – disconnect with actual observations. For instance, there is no evidence that ocean acidification has killed jellyfish predators, nor that jellyfish are taking over the ocean, and predictions that the killer algae, Caulerpa taxifolia, was going to devastate the Mediterranean ecosystem have not been realized, despite claims to the contrary from the media.”
For each criterion, they cite examples of issues for which there is robust evidence, equivocal evidence, and weak evidence.
In the first category, we find that fisheries depletion can be attributed to human impact, as expected, and that this also has a serious impact on marine ecosystems. However, the authors disagree that this means, as one CNN story would have it, that the oceans are “on the brink of collapse”.
Harmful algae blooms like red tides and associated hypoxia (depletion of oxygen), are often attributed to human activity. However, the paper finds that the evidence for this claim, or even that it is a global problem, is ambiguous at best.
Ocean acidification is the notion that increased atmospheric carbon dioxide levels causes an increase in carbonic acid, which in turn causes serious damage to ecosystems because it inhibits calcification in creatures such as corals, molluscs and crustaceans.
Duarte et al. acknowledge that there has been a measurable decrease in ocean pH, and that it is widely expected to reach levels at which it may harm some sea life by the end of the century. However, they dispute claims such as those made in the Seattle Times article cited above, that it has already “killed billions of oysters”, mussels and scallops. The scientific evidence they cite points to other causes.
“There is, as yet, no robust evidence for realized severe disruptions of marine socioecological links from ocean acidification to anthropogenic CO2,” they write, “and there are significant uncertainties regarding the level of pH change that would prompt such impacts.”
Even the larger claim, however, that ocean acidification will pose a major threat to marine animals in the future, has been questioned in scientific circles. A review of some 372 papers on the subject finds that even though experimental research has focused on worst-case scenarios, only a minority found that acidification on the scale scientists expect causes a significant response in marine species. They may be “far more resistant to ocean acidification than hitherto believed”.
The paper is paywalled, but the Ocean Acidification International Coordination Centre agrees with its gist. “Recently ocean acidification as a major threat for marine species has moved from a consensus statement into a much discussed and even challenged conception,” the organisation wrote in 2010.
Perhaps the best example of a scary fiction involving the sea is the alarm about “jellygeddon”. Apparently, jellyfish are taking over the oceans, and we had better be afraid.
The story goes back to a major “bloom” – as a steep increase in numbers is known – in the Mediterranean in the early 1980s. The previous 25 years had been a period of unusual quietude for the species, which made this the first bloom in the region since the birth of modern environmentalism. In reality, it was about time they caused some trouble, like they did often before 1965.
It would take some time before the media picked up the story, however. As with the 1969 Santa Barbara oil spill, it started when the beaches of the rich were affected. The Economist led the pack with a piece entitled “Invasion of the holiday-snatchers”.
For sensation-hungry journalists, the story was too good to check, and it got worse with every telling. “Jellyfish blooms creating oceans of slime,” wrote the BBC. “In the last decade enormous plagues of jellyfish have been taking over the seas. And it is our fault.”
The BBC story was typical of the coverage. In it, the delightfully named environmental journalist Gaia Vince wrote: “Marine ecologists are warning of worse to come, and pointing the tentacle of blame at us.”
An NBC reporter concurred, as did one from CNN: “Driven by overfishing and climate change, the dramatic proliferation of jellyfish in oceans around the world is a sign of ecosystems out of kilter, warn experts.”
Even the supposedly sober academic journal Nature ran a piece with a title straight out of b-grade horror cliché: “Attack of the blobs”.
Jellyfish blooms exist, of course, and they are no laughing matter. They can cause serious damage. They clog the water inlets of nuclear reactors and desalination plants, threaten beach tourism, and pose a serious risk to the livelihoods of fishermen. But are they our fault? Do they present a crisis for ocean ecosystems?
A few scientists have been cited in support of the view that the apparent rise in jellyfish blooms is a serious problem, caused by humans. Notable among these is Lucas Brotz, who wrote a thesis on the idea of jellyfish as human food. “We may need to decide now whether or not we want our children to be eating jellyfish burgers. If our behaviour doesn’t change, they might not have a choice,” he wrote on his website.
Like most coverage of this affair, the BBC article cited only a single expert. In this case, it was Anthony Richardson, the author of a scientific paper entitled “The jellyfish joyride: causes, consequences and management responses to a more gelatinous future.”
However, it wasn’t until deep into the story that Vince thought to mention Rob Condon, who said jellyfish blooms are nothing new. He led a team of scientists that found no evidence of a jellyfish invasion.
Vince lamely concludes: “...no one can say for sure whether blooms are increasing or not”. Well, nobody except the BBC, CNN, NBC, and Nature, all of which did say it.
Subsequent research found that jellyfish blooms occur on natural cycles of about 20 years, and that there is little or no evidence that they have anything to do with ocean degradation.
“Reconsidering Ocean Calamities” argues that an over-emphasis on problems may be intended to motivate actions to reverse the harm, but that this may have the opposite effect. “An overly negative message may lead society into pessimism or the belief that the ocean is beyond restoration,” the authors write. “Indeed, recent media reports on problems in the ocean do not leave much room for optimism.”
The scientific community plays an important role in identifying threats to human welfare and the environment, and in researching remedial actions. However, overstating threats or misattributing their causes leads to unwarranted public fear and to the misallocation of the scarce resources dedicated to mitigating these supposed dangers.
If that isn’t enough of a deterrent to alarmism, there is the risk that scientists, and the media through which they often communicate, lose credibility, and become seen as the boy who cried wolf.
Scott Nixon, a co-author of the study wrote: “Science is a social enterprise, we communicate through the scientific literature, and we must do nothing to undermine the integrity of that communication. Both in sending and in receiving information, we must remain skeptical.”
The same ought to be true for the media. DM