For decades, the Canaticu River on Marajó Island – the largest river island in the world, located in the delta of the Amazon River – provided the main source of livelihood for the local population.
In the last ten years, however, fish and crustacean stocks have fallen drastically in the Canaticu River, and important fish species such as the aracu ( Leporinus friderici ), the bream ( Spondyliosoma cantharus ), the piracucu ( Brachyplathystomafilamentosum ), the (Arapaima Gigas) and hake ( Cynoscion microlepidotus ) have become scarce.
There is no data to prove it, but the anecdotal reality of the inhabitants of the river demonstrates the real situation.
“In the past, we ate fish almost every day. Now we have to buy chicken to consume animal protein”, says Márcio dos Santos, who learned how to fish when he was sixteen, from his parents.
Brought in from other parts of Brazil, the frozen chicken is sold in a supermarket in Curralinho, a municipality where the river flows, in the state of Pará.
The Canaticu River basin has an area of about 12,000 hectares. Historically, local fishing has been essential for subsistence, with the exception of cinnamon shrimp ( Macrobrachium amazonicum ) sold by the so-called Ribeirinhos, river people, and wholesale traders.
They, in turn, resell the product to other states. Over time, the population of this type of shrimp has declined and its size has decreased to something smaller than a human fingernail (in adult males it can reach up to three inches in length).
“A lot of people have moved from the city and countryside to the Canaticu River in the last decade,” says Manoel Potiguar, project manager at the Peabiru Institute, a non-profit organization focused on developing central Amazonian communities in the states of Pará, Amapá, and Maranhão.
Curralinho has 30,000 inhabitants and about 25 percent of the residents live on the banks of the river.
“We started watching the river because we were concerned about the reduction of fish stocks. That’s when we discovered that, the problem was being caused by ourselves.
The only thing we were worried about was fishing in large quantities”, admits Assunção Novaes, president of the Curralinho fishermen’s colony. In 2012, he and other riverside dwellers approached the Peabiru Institute, which had conducted a socioeconomic survey of the Marajó population a few years earlier.
“Our intention was to confirm that the shortage of fish was due to overfishing and, with that, try to find solutions”, says Novaes.
The organization also hired the Center for Genomics and Systems Biology at the University of Pará (UFPA) to study the ichthyofauna of the Canaticu River.
The data would help build a future fisheries agreement to regulate the use of the river’s resources.
“The preparation of the fishing agreement would be mediated by the non-governmental organization, but the fishermen would be responsible for defining the rules, in accordance with their long coexistence with the river”, said Potiguar.
Between 2013 and 2015, representatives from 29 river communities met a total of 23 times to discuss the problems of the Canaticu River. During that same period, a team of biologists from UFPA went on expeditions along the river – which refers to the upper, middle, and lower Canaticu.
“The idea was to obtain scientific knowledge of the species in the region”, says the project’s coordinator, Patrícia Schneider.
At first, as the team approached, the riverside people would run and disappear into the forest. “After some time, we understood why: they thought we wanted to vaccinate them. Since then, we started wearing t-shirts with the project’s logo”, says Patrícia Schneider.
Different from the classic ichthyofauna study – which consists of taking all the fish to the laboratory for analysis – the UFPA team chose to follow the fishermen in the river and the local residents, noting characteristics of the species, such as weight and size.
“It was the best decision we made, given the scarcity of fish and shrimp,” says Schneider. “We only extract a small piece of skin from each sample for future identification, including genetic details.”
For 10 days each month, the five biologists split into small groups to cover the three areas of the river and usually hired extra people who knew the area to drive them around in small boats.
“It takes eight hours of travel just to reach the top of Canaticu, one of the most important areas for fish reproduction and where there is an extractive reserve (RESEX Terra Grande Pracuúba)”, says Schneider.
The site is used as a nursery for some species of fish, from where they come out to run along the course of the river. As it is a spawning area, there is a great concern for its preservation.
The researchers also conducted interviews, examined fishing equipment, and talked about protecting the environment.
This project would go on to collect data for two years during the flood season (from December to May) and the dry season (from June to September).
Many fishermen told biologists that not only were the numbers of fish decreasing but also the size of the species had shrunk.
The riverside people thought that another type of shrimp – other than the cinnamon shrimp – had appeared in the river since the size was much smaller.
Later, the team discovered that the species were actually being fished at a young age, before reaching sexual maturity, preventing growth and reproduction.
“We found seventy types of species and fifteen of them, the most favored ones (for having more meat), were in a state of overfishing”, says Schneider.
According to Santos, residents know that they cannot fish during the closed season, from January to April. But, they do it anyway, as they are easier to catch when they swim upstream to spawn.
Since the 1980s, traditional fishing methods – using traps and hooks, among others – began to be replaced by longer-range equipment on the Canaticu River.
Nylon gillnets up to 330 feet long (or sometimes longer) are some of the new ways used to catch all kinds of species of all sizes. Overfishing had reduced stocks and fishermen had shortened the amount of time between nodes to catch the fish that were left.
“Many still cover the banks of the river with nets well before spawning”, says Potiguar.
Equally unsustainable is the use of the popular “timbó” ( Ateleia glazioviana ), a toxic plant from which the riverside people extract a liquid that is thrown into the river. The poison spreads in the water and intoxicates and kills the fish, which becomes easier to catch.
“This substance contaminates the environment, not to mention the health of people (who consume the fish),” says Schneider.
In the coming months, the results collected by the team of biologists during their two years of research will be published in the Journal of Applied Ichthyology.
In addition to helping the research investigation, the ribeirinho meetings have also helped to raise environmental awareness.
“There has been a lot of debate and, at the end of each meeting, the representatives bring the information to their respective communities, and then discuss the proposals among themselves”, says Potiguar.
It was through this process that the fishing rules were created. The document has 16 rules: the use of gillnets and other fishing instruments is only allowed in accordance with the limits established by the river community and indicated by warning signs; fishing, slaughter, transport, and sale of alligators and turtles are prohibited for an indefinite period.
The use of fishing gear such as explosives, diving spears, and trawls is prohibited; the use of lines and rods is only allowed at the tops of the river and in nursery areas.
Since the Marajó archipelago is considered an environmentally protected area by the Constitution of the State of Pará, the Canaticu agreement must be approved by decree of the Instituto Florestal do Desenvolvimento e Biodiversidade (Ideflor-bio), the body that manages state conservation units. The fishing agreement was filed by Ideflor-bio in March 2015.
A large part of the Ribeira community believes that compliance with fisheries regulations will improve their situation in the long term.
“Successful fishing agreements already exist in the Amazon, and ours was made based on our local conditions”, says Novaes. Supervision will be carried out by the competent environmental authorities, but the riverside people will help to monitor the fishery in the river.
“Everyone will have to follow the rules, and those who defy them will be subject to penalties provided by law: fines, suspension of fishing, confiscation of equipment, and even imprisonment”.
Not everyone, however, agrees with the rules. According to the president of the fishermen’s association, around 30 percent of the riverside population is against them.
Santos, from the Peabiru Institute, estimates that 30 to 40 percent of riverside dwellers still continue to fish during the spawning period (“they are generally 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, with a degree in sociology, Potiguar believes that this stance has to do, in part, with a so-called “cheating mentality”:
“Some people think: ‘I’ll just follow the rules if my neighbor does the same ‘ or ‘if fisheries control is well executed’. That is why environmental education is very important”.
Although there is a lack of scientific backing, residents of the Canaticu River say that some species have reappeared in larger sizes since the project began more than two years ago.
“The first was cinnamon shrimp. It is faster for their schools to recover, as they spend two to three days reproducing every two weeks”, says Novaes.
Hake, aracu, and peacock bass are also returning, albeit more slowly, to fishermen’s tables. “Now, that the riverside people are seeing the river change, the respect (for our project) is even greater”, says Santos.