The Gulf of Guayaquil, the largest estuary on the Pacific coast of South America, provides livelihoods for fishing communities that supply seafood to national markets. Activities like mining and agriculture are major sources of contamination in the estuary, yet their effects on the ecosystem have not been determined. Publicly-available data were compiled to provide an overview of the level of contamination in water, sediment and seafood in this system. Measured concentrations (Cm) were compared with their corresponding permitted levels (Csl) defined in international regulations. Comparison outcomes were classified using a traffic-light color scale: green for ideal conditions (Cm < Csl × 10-1), yellow for alert situations that require precautionary measures (Csl × 10-1 ≤ Cm ≤ Csl × 10), or red for dangerous situations that must be remediated (Cm > Csl × 10). A total of 24 studies were found. Cadmium, mercury and lead were the most commonly analyzed elements. Water samples showed the highest percentage of dangerous levels (> 70 % for Cd, > 80 % for Hg). Extreme concentrations of Hg (1000 times > Csl) were reported for clams (Anadara spp.) and crabs (Ucides occidentalis) collected in the southern zone impacted by gold mining. Studies evidenced the limited use of quality assurance and control procedures on the data-gathering process, resulting in uncertainty. By using orders of magnitude to assess contamination levels, the effects of low precision in the pattern of contamination were reduced. This contribution intends to inform stakeholders about the implications for public health.
The Spermonde Archipelago holds one of the largest artisanal fisheries in Indonesia, providing livelihoods for local communities and many other people involved in international trade networks of seafood. High demand and a lack of enforcement of existing fisheries regulations turn into high pressure for the coral reef ecosystem, contributing to its overall degradation. Estimations on the ecological impacts of different levels of fishing pressure, as well as fisheries stock assessments and marine resource management require precise information of the spatial distribution of fishing effort, which involves great uncertainty when only anecdotal information is considered. We explored the feasibility of applying participatory boat tracking to complement fisheries data during the NW monsoon season 2014-2015. We conducted interviews, measured catch landings, and distributed GPS data loggers among hook and line fishermen to identify fishing grounds by gear-dependent patterns of boat movement. Most of the fishing activities involved two gears (octopus bait and trolling line for live groupers) and three fishing grounds. The mass of catch landings was dominated by Octopoda (CPUE = 10.1 kg boatday −1 ) while the most diverse group was the fish family Serranidae, with Plectropomus leopardus being the main target species. In conclusion, boat tracking combined with interviews and catch surveys has proven a useful tool to reduce uncertainty in information on spatial resource use, while allowing a high level of participation by fishermen.
The decline in wild-caught fisheries paired with increasing global seafood demand is pushing the need for seafood sustainability to the forefront of national and regional priorities. Validation of species identity is a crucial early step, yet conventional monitoring and surveillance tools are limited in their effectiveness because they are extremely time-consuming and require expertise in fish identification. DNA barcoding methods are a versatile tool for the genetic monitoring of wildlife products; however, they are also limited by requiring individual tissue samples from target specimens which may not always be possible given the speed and scale of seafood operations. To circumvent the need to individually sample organisms, we pilot an approach that uses forensic environmental DNA (eDNA) metabarcoding to profile fish species composition from the meltwater in fish holds on industrial and artisanal fishing vessels in Ecuador. Fish identified genetically as present were compared to target species reported by each vessel’s crew. Additionally, we contrasted the geographic range of identified species against the satellite-based fishing route data of industrial vessels to determine if identified species could be reasonably expected in the catch.
Mangroves provide multiple ecosystem services to coastal communities and their fisheries. In the Galapagos, mangroves have been primarily prized for their role as nursery grounds; though, the importance of cultural benefits, including the development of knowledge systems among fishers, needs to be further explored. Fishers’ local ecological knowledge (LEK) has been employed in the past to answer questions about the marine environment; not yet about mangroves. In such regard, this ethnoecological approach can contribute to unveil mangrove habitat-dependence relationships among fishery taxa across the life cycle, connectivity among habitats, and productivity spatial patterns across the archipelago. To access fishers’ LEK, we conducted 35 semi-structured interviews and 2 facilitated community workshops comprising 3 activities. A photo-elicitation method allowed us to extract values given to mangroves (i.e., ecosystem services), from which indirect use values were considered more relevant for fisheries. As such, the accumulation of LEK might have been crucial for the establishment of these values among fishers. By using a species-habitat association method, we revealed a high perceived connectivity between mangroves and other coastal and marine habitats in the Galapagos. Although this suggests an overall weak dependence to the ecosystem, fishers’ anecdotes allowed us to recognize novel species occurrences and exclusive habitat uses (e.g., spawning in Centropomus viridis). By applying Social Network Analysis to species-habitat association results, we learned that certain migratory commercial species (e.g., Lutjanus argentiventris, Seriola rivoliana) might constitute critical links in marine trophic webs and across seascapes. Finally, through scoring and participatory mapping methods, we revealed the prominence of western islands’ mangroves for fishery productivity, which were linked to biophysical attributes, like forest canopy and freshwater. Yet, other locations in central and southeastern islands might also be important, as they hold similar attributes. Interviews to other mangrove users (e.g., naturalist guides, park rangers, scientists; N = 33), and past scientific studies allowed us to triangulate LEK and to find complementarity among knowledge sources. Despite having an explorative focus, our work already showcases the potential of fishers’ LEK in improving mangrove research in the Galapagos, and the arising opportunities for ecosystem-based fisheries management and mangrove protection.
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