Search

Marine finfish landings in Cuba have decreased during the last 30 years. However, in Cuba's most productive fishing region, certain species, including rays, herrings, and snappers, have had increased landings over the past decade. Despite these anomalies, no comprehensive analysis of the interactions among multispecies landing dynamics, environmental factors, and fishing efforts has been carried out. This study estimates the dynamics of multispecies finfish landings between 1981 and 2017 on the southeastern coast of Cuba. A log-normal generalized additive model (GAM) was fit to evaluate the effects of various environmental and effort-related variables on the total landings. During the period analyzed, the finfish landings and fishing effort decreased by 46% and over 80%, respectively. Despite concerns about overfishing, landings per unit of effort (LPUE) increased by 2.8 times. The total fish landings were significantly related to changes in the fishing effort, coastal vegetation, rainfall, chlorophyll-a, and the Southern Oscillation Index (SOI). This study highlights the changing relationship between the landings and fishing effort, suggesting that LPUE may not accurately reflect true stock abundance. The findings of this study will assist in integrating the dynamics of finfish species, ecosystem status, and management actions for Cuba's most productive fishing zone. [ABSTRACT FROM AUTHOR]

Simple Summary: We investigated the ecological role of the squat lobster (Munida gregaria) and the Fuegian sprat (Sprattus fuegensis) in the food web of the Francisco Coloane Marine Area in the Magellan Strait, Chile. We analyzed the ecosystem impacts of biomass changes in the squat lobster and Fuegian sprat. Food web indicators and simulations were estimated using the Ecopath with Ecosim software. Both species were located in the second trophic level. The squat lobster was preyed upon by 12 functional groups, which highlighted its role as an important prey in the ecosystem and its positive impacts on predators such as red cod, whales, and penguins. As prey, the Fuegian sprat presented a direct interaction with 10 functional groups, which exerted positive impacts on predators such as penguins, seabirds and whales. In summary, the Francisco Coloane Area is an immature ecosystem with productivity and energy flows values within those reported for productive ecosystems; the role of the squat lobster seems to be related to the structure of the food web, while the Fuegian sprat plays a role in the energy transfer to top predators. Although the study area is currently a Marine Protected Area, monitoring squat lobster and Fuegian sprat populations might ensure the conservation of this ecosystem. The structure and functioning of the food web of the Francisco Coloane Marine Area in the Magellan Strait, Chile, was quantified, with an emphasis on identifying the ecological role of the squat lobster (Munida gregaria) and the Fuegian sprat (Sprattus fuegensis). Food web indicators, the trophic level, and centrality indices were estimated using Ecopath with Ecosim. Dynamic simulations were carried out to evaluate the ecosystem impacts of biomass changes in squat lobster and Fuegian sprat. The model calculated a total ecosystem biomass of 71.7 t km−2 and a total primary production of 2450.9 t km−2 year−1. Squat lobster and Fuegian sprat were located in specific trophic levels of 2.3 and 2.7, respectively. Squat lobster reduction produced a decrease in the biomass of red cod (42–56%) and humpback whales (25–28%) and Fuegian sprat reduction a decrease in penguins (15–37%) and seabirds (11–34%). The Francisco Coloane Area is an immature ecosystem with productivity and energy flows values within those reported for productive ecosystems; the role of the squat lobster seems to be related to the structure of the food web, and the role of the Fuegian sprat seems to be related to the functioning of the ecosystem and to the energy transfer to top predators. [ABSTRACT FROM AUTHOR]

The present study assessed the effect of sea surface temperature (SST) on the individual growth performance of the thread herring Opisthonema libertate in the southern Gulf of California. For the period from 1988 to 2017, based on monthly length-frequency information, the von Bertalanffy equation's growth parameters (L∞, K, and t0) were estimated annually. Annual values of the growth performance index Φ' were inversely related to the SST (P < 0.05). The values of K and L∞ corresponding to the modal value of the distribution of Φ' were taken as representative of the species, and the temperature change pattern function over time was incorporated as a forcing of the growth coefficient, K, in the growth model. Thus, it was possible to represent the yearly effect of SST on growth performance. These estimates are considered of great interest for future research because they directly influence the variability in allocating the number of individuals at different ages. [ABSTRACT FROM AUTHOR]