Browsing by Author "Subida, Maria Dulce"

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    Effects of harvesting on subtidal kelp forests (Lessonia trabeculata) in central Chile
    (2022) Bularz, Bryan; Fernandez, Miriam; Subida, Maria Dulce; Wieters, Evie A.; Perez-Matus, Alejandro
    The systematic degradation of marine ecosystems is a global phenomenon that has important and diverse consequences including biodiversity loss and reduced ecosystem service provisions. In temperate regions, subtidal kelp forests are dominant ecosystems in rocky coasts, subjected to the influence of local-scale stressors and regional environmental variation. For example, kelps within the Humboldt Current System are at risk of degradation from live-harvesting by fisheries. However, limited information exists regarding the long-term consequences of kelp harvesting, which, in turn, limits the ability to provide effective management and conservation efforts. Here, we examined the ecosystem-level consequences of the artisanal subtidal Lessonia trabeculata fishery along the coast of central Chile during a 2-year period, assessing (1) the change in adult and juvenile L. trabeculata density within harvested and nonharvested (control) plots (similar to 90 m(2)), (2) the impact of L. trabeculata harvesting on reef fish and macroinvertebrate assemblages, and (3) the change in density of the most abundant L. trabeculata-associated species. The experiment was conducted over a 2-year period, from December 2016 to May 2019. Approximately 90% of L. trabeculata was removed by an experienced kelp fisherman in experimental plots. After 2 years, L trabeculata and its associated community showed a lack of recovery in the harvested plots. Within these plots, the average abundance of the rock shrimp, Rhynchocinetes typus, and the herbivorous snail, Tegula tridentata, was greater than in nonharvested plots and the pattern persisted over the study period. The difference in abundance of associated species may be key to the (lack of) recovery of L. trabeculata forests. Our study highlights the impact of L. trabeculata harvesting on associated fauna; however, significant knowledge gaps remain regarding the capacity and time frame to reestablish the original biomass of L trabeculata, as well as its associated fauna. The management of L. trabeculata fisheries needs to account for ecosystem-wide impacts in order to better manage and protect vital coastal ecosystems.
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    Multidimensional data analysis to guide the sustainability of a small-scale fishery affected by poaching
    (2022) de Juan, Silvia; Subida, Maria Dulce; Ospina-Alvarez, Andres; Aguilar, Ainara; Fernandez, Miriam
    The substantial increase in poaching within the fisheries' management areas (MA) system in central Chile is likely driven by an interplay of socio-economic factors. To assess this problem, the exploitation state of an important benthic resource in the MAs (i.e., keyhole limpet) was related to socio-economic drivers of the fishery. The potential drivers of poaching included the level of formal and informal enforcement and distance to sur-veillance authorities, a rebound effect of fishing effort displacement by MAs, wave exposure and land-based access to the MA, and alternative economic activities in the fishing village. A Bayesian-Belief Network approach was adopted to assess the effects of potential drivers of poaching on the exploitation state of limpets, assessed by the proportion of the catch that is below the minimum legal size and by the relative median size of limpets fished within the MAs in comparison with neighboring open access areas. Results showed the important role of socio-economic (e.g., alternative economic activities in the village) and context variables (e.g., fishing effort displacement or distance to surveillance authorities) as drivers of poaching in the study area. Scenario analysis explored variables that are susceptible to be managed, evidencing that an integrative ecological and socio-economic approach can offer solutions to the unsustainable exploitation of marine resources.
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    Temperate rocky subtidal reef community reveals human impacts across the entire food web
    (2017) Pérez Matus, Alejandro A.; Ospina Alvarez, Andrés; Camus Contreras, Patricio A.; Carrasco, Sergio A.; Fernández, Miriam; Gelcich, Stefan; Godoy Salinas, Natalio; Ojeda Rossi, Federico Patricio; Pardo, Luis Miguel; Rozbaczylo Narvaez, Nicolás; Subida, Maria Dulce; Thiel, Martin; Wieters Buchanan, Evie Ann; Navarrete C., Sergio
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    The use of fishers' knowledge to assess benthic resource abundance across management regimes in Chilean artisanal fisheries
    (2021) Garmendia, Vladimir; Subida, Maria Dulce; Aguilar, Ainara; Fernandez, Miriam
    Globally, marine fisheries remain largely unassessed, particularly small-scale fisheries in developing countries. Fishers' knowledge has proven to be valuable to help fill gaps of information in otherwise unassessed fisheries. This study tested the reliability of fishers' knowledge to estimate the abundance of two benthic resources, locos (Concholepas concholepas) and keyhole limpets (Fissurella spp.), across two management regimes, territorial user rights for fisheries (TURF) and open access areas (OAA), over similar to 500 km of coastline in central Chile. Fishers' knowledge (FK) was quantified using systematic interviews and compared to direct assessments (DA). Additionally, resource abundance was compared between the fishing regimes, considering regions with different concentration of TURFs (and consequently different availability of OAAs). The results show that abundances estimated by the two methods were highly consistent for the most valuable resource (the loco) and quite reliable for the keyhole limpet (for 67% of the comparisons). Abundances of both resources were higher in TURFs than in OAAs, a pattern detected by both FK and DA. The results clearly show the potential of this approach to be applied for the Chilean benthic fisheries over large scales. Interestingly, the results also show significantly lower abundance of locos in OAAs than in TURFs at coves immersed in zones with low availability of open access fishing grounds, suggesting the influence of effort displacement after the implementation of TURFs. This ancillary result highlights the need for seascape management plans that consider the potential, unintended effects of TURFs on resources beyond their boundaries. These findings are of both local and global interest, supporting the use of FK to inform management in unassessed small-scale fisheries.