Aumento demográfico del erizo de mar Centrostephanus sylviae en la isla Robinson Crusoe del archipiélago Juan Fernández: Una aproximación biofísica y ecológica.
Loading...
Date
2024
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Universidad de Concepción
Abstract
El aumento de la población de erizos de mar de espinas largas (Centrostephanus sylviae) ha adquirido una atención significativa en la última década debido al aumento del número de individuos reportados como fauna acompañante en las trampas de langosta de Juan Fernández (Jasus frontalis). Además, los riesgos asociados a los cambios en la estructura del ecosistema debido al aumento del blanqueamiento de los arrecifes en el Archipiélago Juan Fernández (JFA) han generado preocupación. En esta investigación se estudió el aumento demográfico de la población de C. sylviae en las islas Robinson Crusoe y Santa Clara (RC-SC) a través de cambios en la abundancia relativa de erizos adultos durante los años 2015-2022. Para abordar esta investigación se se estudió la contribución de erizos en sus primeras etapas de vida a la población adulta a través de modelos biofísicos. Se realizaron simulaciones de patrones de dispersión larvaria y conectividad entre las zonas de liberación y reclutamiento para tres años de estudio (2013, 2015 y 2018). Los resultados de las simulaciones de deriva larval combinados con los datos de observación del programa de monitoreo de la pesca de crustáceos ayudaron a identificar las potenciales zonas de reclutamiento (principalmente ubicadas en las áreas este, sureste y suroeste de RC-SC). Además, se estudió la relación entre la abundancia relativa de erizos de mar adultos y los rasgos asociados a la pesquería de las langostas debido a la relación predador-presa evidente en otros ecosistemas semejantes (tal como son el ejemplo del erizo langosta en Tasmania-Australia y Nueva Zelanda). Se exploró, a través de un modelo lineal generalizado la relación entre la abundancia relativa de erizos adultos y la talla de las langostas capturadas junto a otras variables predictoras (zonas alrededor del AJF, meses de la temporada de la langosta, los años de la series de tiempo, la profundidad de las trampas). Los resultados mostraron que, una vez combinadas todas las zonas, existía una correlación inversa entre la abundancia relativa de erizos de mar y la presencia de langostas de mayor tamaño encontradas en las trampas alrededor de las islas. Este trabajo pone de relieve la compleja dinámica ecológica resultante del aumento de la población de C. sylviae en el sistema JFA, subrayando la importancia de abordar esta preguntamediante enfoques ecosistémicos y socioecológicamente integrados.
The large increase in the population of long-spined sea urchins (Centrostephanus sylviae) has gained significant attention in the past decade due to the rise in the number of individuals reported as bycatch in Juan Fernandez rock lobster traps (Jasus frontalis) and the risks associated with changes in the ecosystem structure due to the increase in bleaching of reefs in the Juan Fernandez Archipelago (JFA). We explored the demographic surge of the C. sylviae population on Robinson Crusoe and Santa Clara islands (RC-SC) through changes in the relative abundance of adult sea urchins during the years 2015-2022. To seek an explanation for this phenomenon, we explored the potential contributions of early life stages of sea urchins to the adult population via biophysical modeling. We performed simulations of larval dispersal patterns and connectivity between release and recruitment zones for three study years (2013, 2015, and 2018). The results from larval drift simulations combined with observation data from the crustacean fishery monitoring program helped identify recruitment zones (primarily located in the eastern, southeastern, and southwestern areas of RC-SC). Also, we explored the relationship between the relative abundance of adult sea urchins and traits associated with lobsters due to the predator-prey relationship evident in other ecosystems (i.e., in Tasmania and New Zealand). We explored the potential control by lobsters of the sea urchin population size through generalized linear models by analyzing several predictor variables. The results showed that once all zones were combined there was an inverse correlation between the relative abundance of sea urchins and the largest lobsters found in the traps around the islands. This work highlights the complex ecological dynamics resulting from the increase in the C. sylviae population in the JFA system, emphasizing the importance of addressing this issue through ecosystemic and socio-ecologically integrated approaches.
The large increase in the population of long-spined sea urchins (Centrostephanus sylviae) has gained significant attention in the past decade due to the rise in the number of individuals reported as bycatch in Juan Fernandez rock lobster traps (Jasus frontalis) and the risks associated with changes in the ecosystem structure due to the increase in bleaching of reefs in the Juan Fernandez Archipelago (JFA). We explored the demographic surge of the C. sylviae population on Robinson Crusoe and Santa Clara islands (RC-SC) through changes in the relative abundance of adult sea urchins during the years 2015-2022. To seek an explanation for this phenomenon, we explored the potential contributions of early life stages of sea urchins to the adult population via biophysical modeling. We performed simulations of larval dispersal patterns and connectivity between release and recruitment zones for three study years (2013, 2015, and 2018). The results from larval drift simulations combined with observation data from the crustacean fishery monitoring program helped identify recruitment zones (primarily located in the eastern, southeastern, and southwestern areas of RC-SC). Also, we explored the relationship between the relative abundance of adult sea urchins and traits associated with lobsters due to the predator-prey relationship evident in other ecosystems (i.e., in Tasmania and New Zealand). We explored the potential control by lobsters of the sea urchin population size through generalized linear models by analyzing several predictor variables. The results showed that once all zones were combined there was an inverse correlation between the relative abundance of sea urchins and the largest lobsters found in the traps around the islands. This work highlights the complex ecological dynamics resulting from the increase in the C. sylviae population in the JFA system, emphasizing the importance of addressing this issue through ecosystemic and socio-ecologically integrated approaches.
Description
Tesis presentada para optar al grado académico de Magíster en Ciencias con mención en Oceanografía
Keywords
Erizos de mar, Biofísica, Biodiversidad marina