Leandro Castello from Virginia gave a fascinating talk regarding the degradation of Amazon fisheries, and focused largely on three main threats: deforestation, hydrological alteration, and overfishing. He discussed overall migratory behaviour of these Amazonian fishes, which only consists of migrating to and from flood plain lakes in relation to annual droughts, and how deforestation negatively affects the catch rate and quality of fishes themselves. He touched upon the 100’s of dams present throughout the amazon, with 100’s more being planned for that region, and then discussed the Arapaima, a large species of fish that is considered a sedentary, obligate air-breather that can get up to a couple of metres in length.
I enjoyed this talk largely because it is very different from the topics of the other colloquiums, focused on a really neat fish species in the Amazon, and it had a core of community-based knowledge and the benefits of local, fisher knowledge. It was great to be able to connect his discussion of the importance of local knowledge, with topics that we have been discussing in NRES 700 of late, the incorporation of traditional ecological knowledge. He emphasized the importance of incorporating local fishers into the data collection to provide them with a role in the conserving their main source of income and food. When locals are part of a study, and take part in data collection, they feel like they’re in involved and in charge, and are more interested in the outcomes of these fishes. Also, they are better at counting the species as they have decades of knowledge based on the fish’s behaviour.
In relation to my study, the mark-recapture aspect of the methods can correlate to my banding of the chickadees. I place colour and numbered bands on the birds, so if they are caught or seen again I will know each individual and will be able to look up their life history traits. Additionally, his methods included a large amount of observations of individuals and behaviours, as will my work with the chickadees.
His PowerPoint slide was filled with relevant imagery and figures, and he explained most of them quite well. He was able to answer questions well, and clearly knew his topic after many years of studying the Amazon fisheries. The question I had was, considering the Arapaima now need to be placed under a strict fishing quota, and kept only if they reach certain measurements in length, what new source of food can the Amazonians rely on? His answer to this was that based on the economic value of the Arapaima, they can now make more money off of the larger fish, which they can then put back into purchasing other food for their families.
All in all, it was a well-planned and organized colloquium talk, and a very interesting subject.