Monday, October 3, 2016

Twilight of the Sawfish

JORI LEWIS

When French oceanographer Anita Conti first journeyed to Senegal in the 1940s, she found ocean waters teeming with giant animals. “The sea,” she later wrote, “is a river of beasts.” Large sharks with heads like hammers or with faded stripes like tigers glided through the water. Giant sawfish, close relatives of sharks, hunted in the shallows. One male sawfish reached seven meters long and likely weighed some three-quarters of a tonne. Another had a face, Conti recalled, like “a pallid nightmare.” Each tooth on the animal’s sawlike snout, or rostrum, she observed, “is a weapon that can penetrate flesh and even wood.”

Before I moved to Senegal five years ago, I knew nothing about these marine giants. But almost as soon as I set foot in Dakar, the country’s capital, I made the acquaintance of the sawfish. As I traded in my US dollars for West African francs, swapping greenbacks for currency that came in a rainbow of colors, I noticed a curious figure on each of the bills and coins. It had a swooping tail and a branch-like nose, and it reminded me of a traditional mask. I eventually learned that it was a representation of a traditional African bronze weight depicting a marine animal—a sawfish. The creature is part of every cash transaction in Senegal, every act of commerce that takes place in the country’s flourishing markets. 

The real sawfish, however, has all but vanished from the country’s coastal waters, though populations can be found elsewhere in the world. Today, fewer than 80 years after Conti’s initial study, overfishing and habitat loss have taken a heavy toll on Africa’s sawfish, reducing populations by more than 80 percent, according to an estimate from the International Union for Conservation of Nature. When Irish researcher Ruth Leeney recently interviewed West African fishers, showing them a picture of a real sawfish, young men were unable to identify it. “They’d turn it around and they’d try to get their heads around what this thing was,” says Leeney, a marine biologist and ecologist at Simon Fraser University in British Columbia. “But if you’ve never seen something like that, then you don’t have any clue what you’re looking at.”

Now researchers struggle to find even lone survivors in areas where the fish once abounded. As I thought about this, I began wondering about the disappearance of the sawfish and what it says about the lives of the people who live along the West African coast. So I set off south in search of answers, leaving the banks and markets of Senegal to meet researchers working in the mangroves and swamps of Guinea-Bissau. In that country of rivers and islands, people have reported sightings of sawfish in recent years.

On a sunny afternoon, I board a small boat and head out with Cécile Brigaudeau along the calm, clear waters of Guinea-Bissau’s Rio Cacine. Brigaudeau works for Des Requins et des Hommes, an international organization devoted to the study and conservation of sharks. A maritime economist by training, Brigaudeau has a no-nonsense manner, something that comes in handy when roping reluctant people into action. She came here to talk with local fishermen about biodiversity and shark fishing, and to investigate reports of sawfish catches in Rio Cacine. She is evaluating sawfish populations for a project known as AfricaSaw.

Rio Cacine is almost as far as far goes in Guinea-Bissau, winding along the country’s southern border. The road to the town of Cacine is all red dirt, green trees, and fields studded with white blossoms. The town sits on the shores of the river and is surrounded by mangrove swamps. From a distance, the mangrove looks monotone. It is only up close that you see the chaos of its tangled limbs; some trees reach to the sky and others to the water as the mangrove expands, breathing and growing.  

These mangroves, says Brigaudeau, serve as nurseries for many marine animals. The brackish waters and labyrinthine channels supply both food and safe shelter for juvenile fish. It looks like a promising place for young sawfish, which are territorial in nature. They “will stay in the same area for probably a year,” Brigaudeau says, so if a local fisher caught a juvenile here last year, other young sawfish could still be around.

Brigaudeau has never seen a sawfish in the wild in West Africa. But other researchers have filled in much of their biology by studying museum specimens, as well as healthier, though still vulnerable, sawfish populations in places such as Florida and Australia.

Sawfish, Brigaudeau explains, belong to the same animal subclass as sharks and rays—the elasmobranchs. While sawfish swim like sharks and serve as top predators in the ocean food chain, they are rays. All sawfish have mouths situated on the underside of their distinctive flat bodies. They usually frequent the sandy bottoms of shallow coastal waters and use their rostra (which are covered with special pores that help sense the movements of prey) to hunt smaller fish and invertebrates, such as shrimp and crabs. A blow from a sawfish rostrum can stun a prey or cut it in two; either way, the sawfish sucks up the wounded and swallows it whole.     

Records show that sawfish inhabit tropical coastal waters from Florida to Bangladesh, and from Africa to Australia. But today, all five species are endangered, and West Africa’s two species—the largetooth and smalltooth sawfish—are critically endangered, meaning they are at a high risk of becoming extinct. So Brigaudeau and her colleagues are trying to establish an alert network in West Africa. They ask fishers who catch a sawfish by accident to take a picture and release it or, if the animal dies, to preserve the carcass. In either case, the fisher is asked to contact AfricaSaw so that it can add the sighting to its database. The goal is to learn where the remaining sawfish live and what their populations look like genetically.  

Sawfish, says marine biologist Armelle Jung, team leader of AfricaSaw, “are still extremely rare” throughout West Africa. But the team’s work is revealing a few “sawfish hot spots,” such as in the protected areas of the Bijagós archipelago and in the winding and twisting estuaries of Guinea-Bissau.

Brigaudeau and Jung hope that Rio Cacine may be one of these hot spots. In a small river channel, Brigaudeau and I clutch mangrove branches to stabilize the little boat. Then the researcher leans over and scoops up a water sample for an experimental project. If a sawfish has frequented this small channel within the past year, it may have shed tiny fragments of skin and tissue, something biologists refer to as environmental DNA (eDNA). By identifying this genetic material in the lab and recording the location of sawfish eDNA, researchers could glean new clues about the animal’s distribution in the region. And by combining these clues with data from local fishers and from other field studies, team members could begin mapping sawfish breeding grounds and seasonal migration patterns—important information for conservation. Research from Florida and Australia suggests that younger sawfish stay in the rivers or close to shore, but adults may wander further offshore.

As the afternoon passes, Brigaudeau hunts for other places in the estuary to sample. Some spots she investigates because a local fisher said he caught a sawfish there; others she chooses by instinct. She watches for grit and twigs floating on the surface, signaling places where the water is stagnant—the very places where samples may reveal the most detailed stories about the life in its depths.

But until Brigaudeau has the lab reports in hand, she has no way of knowing whether she has come even close to these legendary animals.

On a Skype call to Canada, I talk to Leeney, the marine biologist at Simon Fraser University, about her research on the impact of modern fishing practices on West Africa’s sawfish. Baseline data on the historical populations has been hard to come by, but Leeney has gleaned vital clues by combing the studies of early naturalists and scientists, and by heading into the field to collect reports of sightings by local fishers. Her study shows that these massive animals once lived in close proximity to humans along the West African coast, sometimes swimming up estuaries and freshwater rivers where they could tolerate the lower salinity. In the Gambia, for example, an account from 1899 recounted the capture of sawfish hundreds of kilometers upriver.  

But that picture changed dramatically with the advent of the modern fishing industry. As Africa’s population boomed, so, too, did the number of fishers capturing sawfish in their nets. And as industrial fishing trawlers arrived off the African coast, they began raking up enormous quantities of fish. The sawfish often became collateral damage. “They are extremely vulnerable to getting entangled in any kind of fishing net,” says Leeney. “Once they are hooked, they just can’t get out.”

At the same time that the fishery was expanding, the mangrove forests sheltering young sawfish were contracting. Farmers cleared the forest to make way for rice fields, and opportunistic entrepreneurs logged mangroves to obtain lumber for new houses or wood to make charcoal. Dams, wastewater pollution, and industrial accidents such as oil spills have also taken a toll. Between 1980 and 2006, West African mangroves are estimated to have declined by 25 percent.

In addition, new global markets opened up for sawfish fins at the end of the past century. In Guinea-Bissau, fisher Idrissa Conté wishes he could catch a sawfish, as he once did nearly 30 years ago. Back then, his family ate the sawfish meat and he displayed the rostrum on the wall of his house. But today, he says, it would be different. “I would sell the fins!” he exclaims. Asian diners pay high prices for soup made from shark and sawfish fins, which can sell for nearly US $100 per kilogram.

And the practices of trawling and logging, coupled with the fact that the sawfish matures slowly and produces relatively few offspring, now add up to a population crisis. “Of all the places in the world where sawfishes have traditionally lived, I would say that the west coast of Africa is one of the hardest hit in terms of the decline of the sawfish,” says George Burgess, a marine biologist at the Florida Museum of Natural History. “And that’s saying a lot.”

As sawfish numbers falter, so, too, does the cultural memory of the animal. Decades ago, people in Cameroon had proverbs about sawfish, and merchants along the Gold Coast measured quantities of gold dust with bronze weights shaped like these marine animals. Now few people remember the sayings or why metalworkers once cast weights resembling little sawfish. Trying to reconstruct the once-powerful cultural meaning of the animal is like attempting to assemble a puzzle when two-thirds of the pieces are missing. Today, the sawfish seems like a whisper from the African past in a language only a few people remember how to speak. So in Guinea-Bissau, I search for someone who can still conjure up a memory of it.

In the capital, I meet Emanuel Ramos at a popular outdoor cafe where patrons sip espressos and order Portuguese beer. Ramos is a technical assistant with Tiniguena, a local organization that promotes conservation and civic development. His organization has worked with local fishermen in the Bijagós archipelago for more than 20 years.

The old men of Bijagós, Ramos says, sometimes tell stories about how their forefathers set up circular fish traps made of stone in the intertidal zone. “When the tide was high, the fish came into the circle,” Ramos says. “But at low tide, the fish could no longer get out.” The traps made fishing easier, but they also created a kind of aquarium, allowing people to observe sawfish in action as they swam.

Listening to Ramos, I find it easy to imagine other early African communities building similar traps and gathering round to watch the huge creatures caught inside. Seeing a massive sawfish swim over the sand may have inspired myths and sacred stories that helped people make sense of the world and their place in it, and may have given rise to ancient rituals and celebrations. In the remote Bijagós islands, says Ramos, some communities still perform those ancient rites. 

On a hot and humid Friday, I board an early morning ferry to Bubaque, the largest town in the Bijagós archipelago. A friend had advised me to pay a few extra dollars for an air-conditioned cabin with a choice of several long benches for sleeping during the journey. But at 9:00 a.m., the people next to me are drinking red wine and listening to loud music. I flee to the top deck: there’s music pounding there, too, but the sound of the wind, the water, and the engines help to drown it out.

On the four-hour journey, the ferry navigates past islands of mangrove forests and palm trees, and around frequent sandbars that may plague unwary sailors. Only a fraction of the 88 islands in the archipelago are inhabited. Some islands still serve as sacred spaces, where strangers are unwelcome.  

As we pull into port, a crowd gathers on shore—children, market women, and merchants. The ferry sails to Bubaque only once a week, when the tides permit, and people are happy to see it. Although the farmers on the island produce rice, chickens, and palm fruits, many in town look forward to the ferry’s cargo—imported food, drinks, medicines, and phone cards.

My destination for the day is the village of Bijante, where a traditional mask maker, Preto Gomis, lives. His home is a short hike from the port of Bubaque, along a narrow trail that winds past rice paddies, palm trees, and pigs, and I arrive as the day’s oppressive heat begins to dissipate. Gomis, a septuagenarian, sits next to his mud-brick house, mending a basket. Like most of the older men in the village, he wears a length of cloth wound around his body like a toga, a traditional look only slightly marred by the weather-beaten black Crocs that peak out from underneath.  

Gomis makes masks for the many traditional ceremonies and rites of passage held for boys and men in the Bijagós. These events knit together the local society. During early rites, young men offer an important payment of food, labor, and time to the community’s elders. Then as the young men grow older and pass through a series of ceremonies, the male elders share their knowledge bit by bit, passing on vital information about plants, forest animals, and fish.   

For some ceremonies, young men may ask Gomis to make them a hammerhead shark headpiece, with lizards emerging from each edge. Others request the bull mask, with its sharp horns and little bird perched on top. But no matter what they wear, the young men need to show how strong they can be—and dance like the animals depicted on the masks.

Nearly a half-century ago, Gomis picked the sawfish for the mask in one of his own early rites of passage. “I liked how it swam in the water,” he says. Before the ceremony, he went out to sea and caught a sawfish, then sliced off its rostrum with his machete. “When you cut off its nose, it loses its strength,” he says. But as the sawfish weakened, Gomis found new strength of his own. “When I danced the sawfish, I had a lot of courage and a lot of energy. I could dance for hours.” He even brought this sawfish carcass to the ceremony as a sign of his prowess.

Gomis is not the only person who regarded the sawfish as a source of power. In southern Senegal, some families took the animal as their totem—a family emblem and a symbolic protector. And, along the Gulf of Guinea, the Akan people regarded the sawfish as a symbol of prosperity and good leadership. Daniel Mato, a professor emeritus of art history at the University of Calgary in Alberta, told me by email that the sawfish, with its dangerous snout, once served “as a metaphor for the ruler’s willingness to fight for his people, armed with the blade.”

So what happens to traditional cultures when an important animal like this begins to vanish? Gomis looks concerned when I ask him that question. He worries, he says, about the young, who may never learn about the sawfish and the place it occupied in the natural and cultural ecosystem of the Bijagós. And he fears that in the years to come, young men may never gain courage from the dance of the sawfish.


For Gomis and the other elders here, the disappearance of this animal is another major challenge, a kick in the stomach when the fighter is already down for the count. That’s because all of the dances and initiations are slowly disappearing. This age-old way of life can’t compete with school, the internet, and the lure of the world outside of the Bijagós. “We are losing [our traditions] because now we could go five or 10 years without dancing,” Gomis says.

“But I cannot tell [the young] to do otherwise. I can’t. Because people would say that I am crazy if I say that I want them to stay here and dance.”

Twelve years ago, Marine Robillard began surveying residents in West African coastal communities about the cultural importance of the sawfish. Now an environmental anthropologist at a French consulting firm called AnthropoLinks, Robillard says that most people could not believe the sawfish was gone for good. “When we were in Senegal, they would say, ‘Oh, there were some sawfish here but now they have migrated north. Go north.’ When we arrived in Mauritania, they would say, ‘Oh, there are no more sawfish here, but go south, go south.’ And when we arrived in Guinea Conakry, they said, ‘Oh, no, up north.’ People think that this is true for the sawfish, for sharks, and for fish, too. People don’t think they can disappear; they think that they have only moved.”

At AfricaSaw, Jung believes there is still hope. She has yet to see a live sawfish in West Africa herself, but she thinks that targeted conservation measures could help the remaining population rebound. If researchers knew exactly where the remnant populations were, they could manage those small areas. “I think we underestimate the resilience of the area,” says Jung.

But as Brigaudeau calls it a day on Rio Cacine, I am not sure what to think. Some of the spots we visit seem primeval, untouched. At times, the mangroves are so quiet that it feels as if we are completely alone with the birds and the crocodiles. It looks like a refuge here, a place where even huge sawfish might go about their lives undisturbed.  

But we also pass a temporary camp, where fishermen from the region have cut back the mangroves and set up a makeshift shelter on the dark-brown sand. The fish from such camps often end up in markets in the country’s capital and elsewhere. Even the boat Brigaudeau has borrowed is from a South Korean fishing company that owns several big boats and a factory that makes ice to preserve their haul. I ask myself, even if there are a few sawfish here, can they compete in this changed world?

As we head back to town, the river turns choppy with the retreating tide, and our boat thrums and bumps across the waves. Then, suddenly, we spot a few fish jumping from the water. And I remember the words of an old man earlier that day: if you see a fish jump, it could mean a sawfish is below, hunting.   

__
De HAKAI Magazine/Coastal Science and Societies, 14/06/2016

Imágenes:
Illustration by Mark Garrison
Cashing in on sawfish: West African traders once carried bronze weights shaped like sawfish. Today, the image of a sawfish weight graces West African francs. Photo by Michele Burgess/Alamy Stock Photo
So acute are the sensory organs on a sawfish rostrum that the animal can detect its prey even in muddy water. But this rostrum also has a major downside: it frequently gets snarled in fishing nets. Illustration by Mark Garrison
Shorn of its huge rostrum, a sawfish lies on an African beach in this historical photo. A sawfish’s rostrum can account for as much as 28 percent of its overall length. Photo by colaimages/Alamy Stock Photo
Although sawfish swim like sharks, they are classified as rays: they have flattened bodies, with gills situated on their underside. Photo by Peter Atkinson/Alamy Stock Photo
With a sawfish mask on his head, a dancer performs in a ceremony in the Bijagós archipelago in Guinea-Bissau. In many traditional cultures along the West African coast, sawfish are symbols of courage and strength. Photo by Simon Wearne
Once relatively common along the coast of West Africa, the smalltooth sawfish is now critically endangered. Some biologists estimate that more than 80 percent of the population has been wiped out since the early 1960s. Photo by Doug Perrine/Nature Picture Library/Corbis


No comments:

Post a Comment