The new canary in the coal mine could be a giant squid.
Conservation efforts often rally around charismatic species like the African elephant or the bald eagle. Popular affection for these "flagship" animals can be leveraged into funding and political will. But who speaks for the 95 percent of Earth's inhabitants without a backbone? No worm has the rock-star appeal of a Bengal tiger.
Enter the giant squid. Ángel Guerra, a research professor at CSIC (the National Research Council of Spain), makes the case for turning this unusual animal, the largest invertebrate in the world, into a flagship for its marine peers. His enthusiasm for the giant squid has led him to write a book, El Calamar Gigante, containing advice on how to promote ocean conservation with the giant squid.
Given their global distribution throughout the deep sea — Earth's least explored ecosystem — giant squid could be that proverbial canary in the coal mine, a warning of environmental change. But despite their size and range, little is known about the animal known to science as Architeuthis — including whether this canary is even in peril.
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Guerra first had the idea of linking the giant squid to conservation in 2002, when a cacophony of oil-prospecting airgun explosions was followed by nine giant squid deaths in the Bay of Biscay. "One of the specimens was practically destroyed by a direct impact," he says.
He had heard that similar numbers of dead giant squid were sometimes found across the Atlantic, on the beaches of Newfoundland. Thus began an investigation into human impacts on giant squid around the world, culminating in Guerra's flagship species proposal in the July issue of the journal Biological Conservation.
In addition to their susceptibility to noise pollution, which Guerra considers validated by recent laboratory studies on other squid species, giant squid may also suffer from the accumulation of chemical toxins such as heavy metals.
And it's unlikely that Architeuthis will be immune to the effects of climate change. The Newfoundland story told by Guerra and his colleagues links warmer ocean bottom water to more giant squid strandings. In this case, "warm" doesn't mean bathtub temperature. It's the difference between freezing and a few degrees above freezing, which might be enough to disorient the squid.
Like all marine creatures, giant squid face the double whammy of warming water and ocean acidification (more carbon dioxide in the atmosphere drives a decrease in seawater pH). This can make it harder for all cephalopods — squid and their relatives — to breathe. "When you decrease pH for cephalopods just a little bit, most of them quickly begin to struggle to carry oxygen in their bloodstream," says Roger Hanlon, senior scientist at the Marine Biological Laboratory, who has been culturing these animals in captivity for decades. "[A pH measure] is the single most important water quality parameter you look for."
But to Guerra, the greatest threat to the giant squid is fishing. No one catches giant squid on purpose — their flesh is unpalatable — but trawl nets bring them up anyway. Discarded at sea, these carcasses may later be washed ashore. "In the northeast Atlantic there is a total correspondence between fishing and strandings," says Guerra. "When the trawl fishery was closed there were no animal records. In 2009-2010, when the fishery was re-opened, there were seven animals."
If 10 or even a hundred giant squid are killed annually by fisheries, that number pales in comparison with the thousands of unintended deaths endangering species like sea turtles. Could giant squid really be affected by relatively small losses?
It depends on how many squid are out there, and "nobody knows the size of the populations of Architeuthis," admits Guerra.
"From a scientific point of view, all of these arguments are highly speculative," Hanlon points out. Data are so limited that no one can be sure what effects pollution, climate change and fishing might have on giant squid. "Out of all the invertebrates," says Hanlon, "I am surprised that they would pick a species for which so little is known."
Research on giant squid has been limited by necessity — nearly all specimens are found dead or dying, floating at the sea surface or stranded on beaches. Japanese researcher Tsunemi Kubodera filmed the first live giant squid in 2006, and scientists are still a long way from being able to capture and keep them in aquariums.
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Whether or not the giant squid is an ecological canary may be irrelevant to its potential as a flagship species, argues Diogo Verissimo at the Durrell Institute of Conservation and Ecology. The biologist says a flagship species is, after all, a marketing concept, not an ecological one. In a recent review in Conservation Letters, Verissimo and his co-authors urge conservation scientists to embrace marketing principles in selecting flagships. They believe that confusing the marketing "product" of a flagship species with the biological nature of the species itself hurts conservation.
Guerra, who focused his proposal on the biology of the giant squid, disagrees. Verissimo declined to comment directly on Guerra's work, as he is currently leading a group of scientists in composing a written reply.
Both researchers, however, highlight the lack of unconventional flagship species in the world of conservation, noting that the same familiar vertebrates tend to be used and re-used. The giant squid may not rival the giant panda in popularity, but, in standing for marine invertebrates, it represents a much greater diversity of life.
And, as Verissimo points out, popularity can be influenced through marketing.
A useful first step would be to discover the audience's innate preferences in "spokes-animals." In North America and Europe, says Verissimo, "One thing that really drives people is body size." As the largest invertebrate in the world, the giant squid has a clear advantage in this realm. Architeuthis grows up to 60 feet long, and although most of that length comprises the spidery tentacles, the main body can reach a still-impressive 16 feet.
In a place like Tanzania, on the other hand, people prefer herbivores to carnivores. The giant squid, certainly no grass-eater, may lose traction here. The villain of 20,000 Leagues under the Sea doesn't attack humans outside of fiction, but the reputation lingers.
Even in the industrial world, carnivores can draw a schizophrenic public reaction. Look at wolves. "It's exactly the same species, the wolves are exactly the same," says Verissimo. "And one audience is willing to invest time, money and effort to conserve them, and a different audience does exactly the opposite, investing time, money and effort to kill them."
But in addition to its enormous size, the giant squid holds a trump card: the very mystery that makes assessing its vulnerability so difficult. The plethora of unanswered questions about this animal draw fascinated crowds to giant squid exhibits around the world.
The Centre for the Giant Squid in Luarca, Spain, is the world's only museum entirely devoted to Architeuthis. The 11 specimens on display attract a constant stream of visitors and are periodically rented out to other museums. "Giant squid are very good moneymakers," comments Guerra, who has dissected and studied all of the center's animals.
One point on which Guerra and Verissimo would surely agree is the value of applying their academic research to the practical world of conservation.
"One of the great problems with academia is everyone talking to each other inside, not going outside and seeing if their research is having an impact," says Verissimo. "Any time I can see my research going out into wider society, that's great."