Site icon Conservation news

Managing fish stock –and fishermen– along Brazil’s Canaticu River

  • Over the past ten years, though, fish and crustacean stocks have fallen dramatically along the Canaticu River.
  • Data on Canaticu’s ichthyofauna helped build a fisheries agreement, which would regulate the use of the river’s resources.
  • Although they lack scientific backing, the residents of the Canaticu River say that some species are showing up in bigger sizes since the project began.
Ribeirinhos setting out to fish along the Canaticu River. Photo courtesy of Naiana Thiely.
Ribeirinhos setting out to fish along the Canaticu River. Photo courtesy of Naiana Thiely.

For decades, the Canaticu River on Marajó Island —the world’s largest fluvial island, located in the Amazon river delta— provided the main source of livelihood for its local population. Over the past ten years, though, fish and crustacean stocks have fallen dramatically along the Canaticu, and important fish species, such as the aracu (Leporinus friderici), the dourada (Spondyliosoma cantharus), the filhote (Brachyplathystomafilamentosum), the piracuru (Arapaima gigas) and the pescada (Cynoscion microlepidotus) have become scarce.

There is no data, but the anecdotal reality of the river’s inhabitants paints a picture of ​​the situation. “In the past, we ate fish almost every day. Now we have to buy chicken to consume animal protein,” says Marcio dos Santos, who learned how to fish when he was sixteen, with his parents. Brought from other parts of Brazil, the frozen poultry is sold in a supermarket in Curralinho, the county where the river flows, in Pará state.

The Canaticu River basin has an area of about 12,000 hectares. Historically, local fishing has been essentially for subsistence, with the exception of the camarão canela (Macrobrachium amazonicum), sold by the so-called ribeirinhos, or river people, to wholesale merchants. They, in turn, resell the product to other states. Over time, the population of this type of shrimp has declined and its size has even decreased to something no bigger than a human fingernail (adult males can reach three inches in length).

“Many people have moved from the city and inland to the Canaticu River in the last decade,” says Manoel Potiguar, project manager of Peabiru Institute, a nonprofit focused on the development of the central Amazonian communities of Pará, Amapá and Maranhão states. Curralinho has 30,000 inhabitants and about 25 percent of them live in the river and along its banks.

“We started to watch the river because we were concerned about the fish stock reduction. That was when we realized that the problem was being caused by ourselves. The only thing we cared about was to fish in big quantities,” admits Assunção Novaes, president of the Curralinho fishermen colony. In 2012, he and other ribeirinhos got in touch with Peabiru Institute, which had conducted a socio-economic survey of the Marajó population some years before. “Our intention was to confirm that the fish shortage was due to overfishing and, from there, try to find solutions,” says Novaes.

The organization was also commissioned the Center for Genomics and Systems Biology of Pará Federal University (UFPA) to study Canaticu’s ichthyofauna. The data would help build a future fisheries agreement in order to regulate the use of the river’s resources.

“The preparation of the fisheries agreement would be mediated by the NGO, but it was the fishermen themselves who would be responsible for the definition of the rules, out of their long coexistence with the river,” said Potiguar.

Mapping the Canaticu River. Photo courtesy of Instituto Peabiru.
Mapping the Canaticu River. Photo courtesy of Instituto Peabiru.

Between 2013 and 2015, representatives of the 29 river communities gathered a total of 23 times to discuss the problems at Canaticu River. During the same period, a team of UFPA biologists headed out on expeditions across the river –referred to as high, medium and low Canaticu. “The idea was to acquire scientific knowledge of the species in the region,” says project coordinator Patricia Schneider.

In the beginning, as the team approached, the ribeirinhos would run and disappear into the forest. “After a while we understood the reason: they thought we wanted to vaccinate them. Since then, we began to wear t-shirts with the logo of the project,” says Schneider.

Unlike classic ichthyofauna research —which involves taking whole fish to the laboratory for analysis—, the UFPA team chose to follow the fishermen on the river and back to the locals’ homes, writing down the characteristics of the species, such as weight and size. “It was the best solution given the lack of fish and shrimp,” says Schneider. “We only extracted a small piece of skin from each sample for later identification, including genetical details.”

For ten days every month, the five biologists divided themselves into smaller groups to cover the three areas of the river, and usually hired extra people who knew the region to drive them around in small boats.

“It takes eight hours of travelling just to get to high Canaticu, one of the most important areas of fish breeding and where there’s an extractive reserve (RESEX Terra Grande Pracuúba),” says Schneider. The site is used as a nursery for some fish species, from where they leave to run along the river’s course. Because it’s a spawning area, there is huge concern for its preservation.

The researchers also conducted interviews, examined fishing equipment, and talked about environmental protection. Their project would go on to gather two years’ worth of data during the flood season (from December to May) and the dry season (from June through September).

A traditional fisherman heads out at dawn. Photo courtesy of Naiana Thiely.
A traditional fisherman heads out at dawn. Photo courtesy of Naiana Thiely.

 

Many fishermen told the biologists that not only had the quantity of fish diminished, but also the species’ size had shrunk. The ribeirinhos thought that another kind of shrimp –other than ‘camarão canela’– had shown in the river, since it was much smaller in size. Later on, the team discovered that the species were actually being caught at a young age, before reaching sexual maturity, so they couldn’t grow and reproduce. “We found seventy types of species and, fifteen of them, the most favored ones (because they had more meat), were in a state of overfishing,” says Schneider.

According to Santos, locals know they can’t fish during the closed season from January to April. But they do it anyway, because it’s easier to catch them when they swim upriver to spawn.

Since the 1980s, traditional fishing methods —done with traps and hook-and-line, among others)– began to be replaced by longer range equipment in the Canaticu River. Gillnets made of nylon and up to 330 feet long (or sometimes longer) are some of the new ways used to catch all kinds of species and in all sizes. Overfishing had reduced stocks, and fishermen decreased the amount of time between nodes to capture the fish that were left. “Many still cover the river banks with a net right before the spawning, which is illegal,” says Potiguar.

Equally unsustainable is the use of the popular ‘timbó’ (Ateleia glazioviana), a toxic plant from which the ribeirinhos extract a liquid that is thrown into the river. The poison spreads in the water and intoxicates and kills the fish, which become easier to catch. “That substance contaminates the environment, not to mention the health of the people [who consume the fish],” says Schneider.

In the coming months, the findings collected by the team of biologists during their two years of research will be published in the Journal of Applied Ichthyology.

Besides aiding the scientific research, the ribeirinhos‘ meetings have also helped to raise environmental awareness. “There has been a lot of debate and, at the end of each meeting, the representatives have brought the information to their respective communities, and then discussed the proposals among themselves,” says Potiguar.

It was through this process that the fisheries rules were created. The document has 16 rules: the use of gillnets and other fishing tools are only allowed in accordance with the limits established by the river communities and indicated by warning signs; the catch, slaughter, transportation and sale of alligators and turtles is prohibited for an indefinite period; it’s forbidden to use fishing gear such as explosives, diving spear and trawls; the use of line and rods is only allowed in river heads and nurseries areas.

Because the Marajó archipelago is considered an environmentally protected area by the Pará state constitution, the Canaticu agreement must be approved by ordinance of the Forest Development and Biodiversity Institute (IdeflorBio), an agency that manages the state conservation units. The fisheries agreement was filed by IdeflorBio in March 2015.

A great part of the riverside community believes that compliance with the fisheries’ rules will improve their situation in the long term. “There are already successful fisheries agreements in the Amazon, and ours was done based on our local conditions,” says Novaes. The supervision will be carried out by the competent environmental authorities, but the ribeirinhos will help monitor fishing in the river. “Everyone will have to follow the rules, and those who defy them will be subject to the penalties provided by law: fines, fishing suspension, confiscation of equipment, and even imprisonment.”

Not everybody, however, agrees with the rules. According to the president of the fishermen’s association, about 30 percent of the riverside population is against them. Santos, of the Peabiru Institute, estimates that 30 to 40 percent of the ribeirinhos still continue to fish during the spawning period (“they are usually older and retired,” he explains). According to Potiguar, the disagreement represents a minority, “but our fear is that they end up influencing others.” Born in Ourém, Pará, and with a degree in sociology, Potiguar believes that this stance has to do, in part, with a so-called “trickster mentality”: “Some people think: ‘I’ll just abide by the rules if my neighbor does the same’ or ‘if the fisheries monitoring is well executed’. That’s why is so important environmental education.”

Although they lack scientific backing, the residents of the Canaticu River say that some species have been showing up again in bigger sizes since the project began, more than two years ago. “The first was the camarão canela. It’s faster for its shoals to recover because they spend two to three days reproducing every two weeks,” says Novaes. The pescada, the aracu and the tucunaré are also returning, albeit more slowly, to the fishermen’s tables. “Now that the ribeirinhos see how the river is changing, respect [for our project] is greater now,” says Santos.

A biologist with the Instituto Peabiru team examines the size of fish caught along the Canaticu River. Photo courtesy of Patricia Schneider.
A biologist with the Instituto Peabiru team examines the size of fish caught along the Canaticu River. Photo courtesy of Patricia Schneider.
The samples are taken to the genetics lab. Photo courtesy of Patricia Schneider.
The samples are taken to the genetics lab. Photo courtesy of Patricia Schneider.
Exit mobile version