By Fábio Daura
Time is essential to understand how natural environments work, and sometimes that means a long time. Ecology is a complex science that demands patience, determination and creativity to answer small questions, with which we can solve a huge puzzle. That means, by understanding small parts of a natural ecosystem we can understand it as a whole. So decisions can be taken aiming for adequate resources use and ecosystem services provision. For that to happen we need time and financial support.
Fortunately, since 1999 the National Council for Scientific and Technological Development (CNPq) has established a Long Term Ecological Research program (PELD), which nowaday counts 37 sites from different ecosystems in Brazil. At these sites ecological studies with a long time series of data collection are conducted. In 2021 a new site called Long Term Ecological Research program from the Laguna Estuarine System and adjacent areas (PELD SELA) was implemented.
Although it is a new PELD, numerous studies have been developed at the site during the last decades. That means different research groups are engaged in solving questions from distinct ecosystem’s components. Thus, apart from expanding research efforts, one of PELD SELA’s main goals is to connect research groups. This effort’s integration is essential to set conservation priority goals and also to better understand the ecosystem.
Therefore, our objectives are organized in a logical way so the answer of one question provides essential information for answering the next question and so on. That means our objectives are connected from the first to the last, and our main objective is the icing of the cake.
For example: the Laguna Estuarine System has plenty of ecological components to be studied, some are extremely important for the local community, especially for the fishing community. We know a key feature for this system is the traditional fishery that occurs in cooperation with bottlenose dolphins that inhabit the estuary. During the last few years our group has been systematically investigating the interaction between dolphins and fishers, monitoring the dolphin’s population and the artisanal fishery itself. Now, in the PELD context, we will aggregate what we already know with new data to describe the interaction’s mechanisms in detail and its benefits for both dolphins and fishers (objective 1). Also, we will continue to monitor the dolphin population (objective 2) to evaluate if it is increasing or decreasing, and we will intensify the monitoring efforts on the artisanal fishery (objective 3) to understand its dynamics along time and space. Some of or objectives are theoretical (objectives 4 and 5) and will need to gather the informations of objectives 1, 2 and 3 in order to predict what can happen in the future with the dolphin population and also with the artisanal fishery if the current environmental conditions persists, or even if it worsen (increase of pollution, aquatic traffic and bycatch).
Then, using the results from objectives 4 and 5 combined with a great effort of data collection of other species we will execute both ecosystem modeling (objective 6) and bionomic modeling (objective 8). These modeling will, respectively, help us understand the ecological relationships between species and its economic consequences for fishery. A few questions that we will try to answer: if the dolphin population decreases, what will happen with fishery and with other species of the ecosystem? If the fishery’s dynamic and the abundance of other species changes, what will happen with the fishery’s economic returns?
Anyway, we are organized to answer a lot of questions in the years to come. It is a big challenge but also a quite fascinating one. We will use a great variety of methods to collect and analyze data, plenty of complex modeling and also simple protocols that value background information and empirical knowledge. We are motivated and filled with expectations for the next 4 years, shall we have interesting answers and instigating new questions.
The Laguna Estuarine System is worthy of this PELD.
Lagoon system. Source: Fábio Daura
Interaction History and Search Efforts
By Paulo C. Simões-Lopes
Suddenly, we reached the edge of a lagoon with the shores full of reeds. Fishermen weave their nets made of vegetable fibers or sheep’s guts as they said to refer to animal tendons. Nylon had not yet been invented.On the edge of the lagoon flourished a city in colonial style. There was a market, a mooring, and a newspaper. It was the homeland of Anita Garibaldi, the heroine of two worlds. It was the ancient land of the Carijó ethnicity. But then, a dozen years before the turn of the century, the city newspaper published a curious story of “porpoises that interacted with fishermen.” This was the first record of an event that would be understood only a hundred years later.
In the 1970’s the mouth of rivers and lagoons in southern Brazil would be fixed by rocky treours, facilitating navigation. The navigable channels would be deepened, nylon would be invented, cast nets would become larger and more efficient, however, generations of porpoises and human fishermen would continue their relationship of exchanges and advantages.
The porpoises would gain names and be recognized individually by the fishermen, giving life to an oral tradition that continues to this day. Porpoises and fishermen taking advantages in catching mullets and some other species of fish. In 1995 an award-winning doctoral thesis would test the advantages of this relationship and its weaknesses. For the first time it would be clear that these were bilateral mutualist advantages, as ecology explains: fishermen catching more larger fish and fish that cannot be easily seen in the murky waters of the lagoon; porpoises making use of fishermen to disintegrate the shoals. Each one winning by the other’s presence. For the first time, an extra-human cultural tradition for Laguna porpoises would be described.
This could be studied by counting and measuring fish and more fish in the cast nets, taking thousands of photographs of porpoises, counting the throws of nets, describing behaviors of porpoises and registering each of them, interviewing fishermen, following the porpoises in a small boat with a small engine of 4hp and estimating the population of porpoises that used the system of ponds of what was once the locality of Santo Antônio dos Anjos da Laguna or Laguna. Technology would make new leaps with digital photography, photogrammetry, image editing programs, modern statistical modeling, and the complex networks of relationship between each button. Then a second doctoral thesis in 2011 revealed who was who. Which porpoises interacted the most with the fishermen and how they related to each other, revealed that the porpoise population had remained stable for 30 years and that these ‘cooperative’ porpoises needed to move less to survive there.
Human traditions and fishing gear would be explained in detail, the death and birth of porpoises, carefully monitored, their complex underwater sound, human impacts, the cause of death of these animals, their importance as “environmental service”, high quality environmental education, all studied in so many monographs. So many people dedicating hours on end to counting, calculating, shooting, recording under rain and sun and wind… (see all these scientific publications in https://www.lamaqufsc.com.br/artigos).
UFSC’s Laboratory of Aquatic Mammals (LAMAQ) and the UDESC Department of Fisheries Engineering, fulfilling a research tradition that is already in its good 30s, now successfully embraces a Long-Term Ecological Research Program (PELD). Now more arms and minds combine in a common goal. That’s the science we want. That’s the science we offer!