Papers by Josymar Torrejón-Magallanes
Journal of thermal biology, Jun 1, 2024
Regional studies in marine science, Jul 1, 2024
bioRxiv (Cold Spring Harbor Laboratory), Dec 6, 2023
Anthropogenic climate warming will change the thermal habitats of marine species worldwide. Speci... more Anthropogenic climate warming will change the thermal habitats of marine species worldwide. Species are expected to migrate to higher latitudes as warming intensifies since behavioral and physiological mechanisms have been adapted to maximize fitness under a specific range of temperatures. However, given the possible intensification of upwelling ecosystems, they may act as potential thermal refugia under climate warming, which could protect the diversity of the marine ecosystems, making them important regions for marine resource management. This research aimed to predict the effects of climate warming on commercial and non-commercial marine species (vertebrate and invertebrates) reported in official Mexican documents (> 300 species) based on a thermal niche characterization with the objective to observe if the upwelling regions can act as potential thermal refugia. For this, we considered Representative Concentration Pathway (6.0 and 8.5) scenarios for the present and the future (2040-2050 and 2090-2100). Current and future patterns of suitability, species distribution, richness, and turnover were calculated via ecological niche models using the minimum volume ellipsoids as an algorithm. The results in this study highlight that beyond migration to higher latitudes, some upwelling regions (not all) could be potentially used as some type of "oasis" by marine species refuging from environmental pressure or zones of higher stability of species. Specifically, the upwelling systems in western Baja California and north of Yucatan may be essential regions for future management in Mexico. Nevertheless, it is important to note that climate change acts on numerous ecosystem features, such as trophic relationships, phenology, and other environmental variables not considered here. Future research could test our hypothesis under more realistic simulations. However, migration toward upwelling regions seems to be the most logical selection from all the available ecosystems as climate refugia for marine species beyond movement to higher latitudes or depths.
PeerJ, Apr 19, 2021
How to cite this article Torrejón-Magallanes J, Morales-Bojórquez E, Arreguín-Sánchez F. 2021. Im... more How to cite this article Torrejón-Magallanes J, Morales-Bojórquez E, Arreguín-Sánchez F. 2021. Improving the gnomonic approach with the gnomonicM R-package to estimate natural mortality throughout different life stages.
Deep Sea Research Part II: Topical Studies in Oceanography, 2018
Temporal changes in mesoscale aggregations and spatial distribution scenarios of the Peruvian anc... more Temporal changes in mesoscale aggregations and spatial distribution scenarios of the Peruvian anchovy (Engraulis ringens),
PeerJ
Natural mortality (M) is defined as the rate of loss that occurs in a fish stock due to natural (... more Natural mortality (M) is defined as the rate of loss that occurs in a fish stock due to natural (non-fishing) causes and can be influenced by density-dependent or density-independent factors. Different methods have been used to estimateM, one of these is the gnomonic approach. This method estimatesMrates by dividing the life cycle of a species into subunits of time that increase as a constant proportion of the time elapsed from birth up to the initiation of each subdivision. In this study, an improved gnomonic approach is proposed to estimate natural mortality throughout different life stages in marine stocks using thegnomonicMpackage written in R software. This package was built to require data about (i) the number of gnomonic intervals, (ii) egg stage duration, (iii) longevity, and (iv) fecundity. With this information, it is possible to estimate the duration and natural mortality (Mi) of each gnomonic interval. ThegnomonicMpackage uses a deterministic or stochastic approach, the ...
Boletin Instituto del Mar del Perú, Dec 10, 2018
Se estimaron valores de la talla de madurez gonadal (L50) de la caballa (Scomber japonicus peruan... more Se estimaron valores de la talla de madurez gonadal (L50) de la caballa (Scomber japonicus peruanus) para los anos 1994 – 2017 en el litoral peruano. El analisis se realizo para el periodo noviembre - marzo donde ocurre la mayor actividad reproductiva. La proporcion de hembras maduras en relacion a la talla se ajusto mediante un modelo logistico binomial, para ello se utilizaron modelos lineales generalizados con efectos mixtos (MLGM) que asumieron efectos aleatorios asociados a los periodos. El ajuste con el MLGM, mediante sus efectos fjos estimo una L50 de 24.8 cm de longitud a la horquilla (LH) (24.69 cm – 24.9 cm), mientras que con cambios entre periodos, mediante sus efectos aleatorios, los valores oscilaron entre 20.4 cm y 27.0 cm de LH en promedio. Se observo que un aumento en la temperatura causo la disminucion de la L50 en los periodos 1997 – 1999 y 2015 – 2016, los cuales coinciden con la presencia de eventos El Nino. Una correlacion positiva fue encontrada entre las L50 y...
Estuarine, Coastal and Shelf Science
Deep Sea Research Part II: Topical Studies in Oceanography
Revista Peruana de Biología, 2016
En este trabajo se presenta la estimación del descarte por exceso de captura en la pesquería indu... more En este trabajo se presenta la estimación del descarte por exceso de captura en la pesquería industrial de cerco del stock Norte-Centro de anchoveta peruana. Se define el descarte por exceso de captura, como la porción de captura que se arroja al mar cuando se ha capturado más de lo que la capacidad de bodega de la embarcación puede almacenar. El análisis de estimación para el periodo 2005 - 2014, se realizó a partir del “Programa de observadores a bordo de la flota de cerco” que ejecuta el Instituto del Mar del Perú (IMARPE), en donde 5 837 viajes, que representan el 1.6% de los viajes totales, fueron muestreados. Las metodologías utilizadas en la estimación fueron: Modelo Lineal Generalizado (GLM) y el Modelo Delta. Las estimaciones por el Modelo Delta y el GLM fueron diferentes en magnitudes pero similares en tendencias, sin embargo la evaluación del funcionamiento del Modelo Delta, indica que este modelo se ajusta mejor a los datos. El Modelo Delta estimó que la pesquería descar...
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Papers by Josymar Torrejón-Magallanes