Fishing with Pesticides Affects River Fisheries and Community Health in the Indio Maíz Biological Reserve, Nicaragua

Abstract

The practice of harvesting fish and crustaceans by using pesticides is understudied and under-reported in tropical inland fisheries yet poses a significant threat to freshwater biodiversity and community health. This research provides a brief review of the practice and an in-depth case study from southeast Nicaragua. In 2019, 86 interviews and 5 focus groups were conducted in remote communities in the Indio Maíz Biological Reserve (IMBR) and nearby surrounding area and combined with 4 years of local Indigenous Rama and Afrodescendent Kriol community forest ranger data. Forest rangers and 74% of interviewees reported that fishing with pesticides occurs in their communities, including both inside the IMBR and in the nearby surrounding area. The practice is primarily used by illegal settlers, and not by Rama and Kriol communities who have rights to the land in the IMBR. It entails the release of liquid pesticides in water or mixing powdered pesticides with corn flour and using the mixture as bait. Of seven chemicals reported, Cypermethrin, Deltamethrin, and Aluminum Phosphide were most common. The use of ichthyotoxic woody plants was more rarely reported. Habitats targeted ranged from swift headwaters to slow pools in small creeks to larger rivers, depending on target species. Main uses reported for the catch were food for family, bait to catch larger fish, and for sale. The main motivation was increased catch efficiency. Many interviewees attributed stomach issues, diarrhea, cough, convulsions, and miscarriage to exposure to poisoned river water. Twenty-five interviewees blamed poisoned rivers for livestock miscarriages or death. Severe local losses of fish and shrimp populations were reported. Rama and Kriol interviewees describe the practice as a threat to their river-based food security. Despite its illegality, no study participant knew a case of pesticide fishing that had been prosecuted. This destructive fishing practice has significant implications for conservation of the intact river systems of the primary rainforests of southeast Nicaragua, and to the local traditional fisheries they support.

Re-evaluation Survey of Fish Composition, Abundance and Distribution in Agbokim Waterfalls, Nigeria

“…Similar studies Olele et al [25] followed the same pattern on the composition, abundance and distribution of fishes in Onah Lake, Asaba, Nigeria, showed that site C was the most abundant with 1009 fish species followed by site A with 880 individuals and site B with the least abundance. The number of individuals in the present study, is far lower than that of the previous study Ikpi, [9] which has supports the possibility of a negative impact of anthropogenic activities, faulty agricultural practices leading to soil erosion and runoff of chemicals such as pesticides and fertilizers into the waterfalls, which is similar to the findings of Betts et al [4] that pesticides generally reduce the abundance and diversity of fish and aquatic invertebrates in rivers and streams that receive polluted runoffs [5] [6]. The present study is also higher than Ndome et al [26] on the ichthyofauna of the upstream and downstream reaches of the Kwa Falls, Oban, Cross River State, Nigeria with a total of 562 fish representing 12 species belonging to 11 genera from 10 families and 6 orders; and also higher [27] in the investigation of Otamiri River, with a total of 129 benthic fish fauna belonging to 5 species and 4 families with Chrysichthys nigrodigitatus (32.65%) as the most dominant fish species and Synodontis soloni (2.18%) as less dominant.…”

“…The effects of these changes on aquatic systems are severe especially where there is increasing demand for freshwater resources generated by continued growth in human population, urbanization, industrialization, irrigation and agricultural development, which cause serious alterations of the aquatic communities [3]. For example, in aquatic systems, it is well known that pesticides generally reduce the abundance and diversity of fish [4] and aquatic invertebrates and cause changes in community composition in rivers that receive polluted runoff [5] [6]. In extreme cases, pesticide runoff from agriculture can result in large fish kills [7].…”

Assessment of Fish Quality Based on the Content of Heavy Metals

“…Organic substances like pesticides are harmful to fish, which can be said to reduce the health properties of fish meat [ 15 ]. According to Betts et al [ 16 ], the practice of using pesticides is a threat not only for inland fisheries, but it is a global problem, because as a consequence, it can be harmful for human health.…”

Rates of tree cover loss in key biodiversity areas on Indigenous Peoples’ lands

“…From the advent of colonialism to the present, Indigenous Peoples have a history of disempowerment in states that have asserted ownership of their traditional lands. Many Indigenous Peoples often have no legal ownership or tenure rights over their traditional lands and, for many of the countries where losses of forest have been greatest on IPL outside PAs, disenfranchisement has been strongly manifest in recent decades (e.g., Cameroon, Beckline et al., 2022; Bryan, 2019; Nicaragua, Betts et al., 2020). Even where IPL are managed by Indigenous Peoples with a conservation aim, governance and contextual factors, such as incentives for mining and access and use of IPL, might also lead to deforestation.…”