Drivers of reef fish assemblages in an upwelling region from the Eastern Tropical Pacific Ocean

Abstract

Reef fish assemblages are exposed to a wide range of anthropogenic threats as well as chronic natural disturbances. In upwelling regions, for example, there is a seasonal influx of cool nutrient‐rich waters that may shape the structure and composition of reef fish assemblages. Given that climate change may disrupt the natural oceanographic processes by altering the frequency and strength of natural disturbances, understanding how fish assemblages respond to upwelling events is essential to effectively manage reef ecosystems under changing ocean conditions. This study used the baited remote underwater video stations (BRUVS) and the traditional underwater visual census (UVC) to investigate the spatiotemporal patterns of reef fish assemblages in an upwelling region in the North Pacific of Costa Rica. A total of 183 reef fish species from 60 families were recorded, of which 166 species were detected using BRUVS and 122 using UVC. Only 66% of all species were detected using both methods. This study showed that the upwelling had an important role in shaping reef fish assemblages in this region, but there was also a significant interaction between upwelling and location. In addition, other drivers such as habitat complexity and habitat composition had an effect on reef fish abundances and species. To authors’ knowledge, this is the first study in the Eastern Tropical Pacific that combines BRUVS and UVC to monitor reef fish assemblages in an upwelling region, which provides more detailed information to assess the state of reef ecosystems in response to multiple threats and changing ocean conditions.

Comparación de cuatro métodos para contar peces en una bahía tropical: el caso del Área Marina de Manejo Bahía Santa Elena en el Pacífico de Costa Rica

“…La Bahía Santa Elena (BSE), ubicada en el Pacífico Norte de Costa Rica, fue declarada un AMM en el 2018 debido a que posee una gran variedad de hábitats esenciales para peces y otros organismos, incluyendo arrecifes coralinos y rocosos, planicies arenosas y lodosas y desembocaduras de ríos rodeados por bosque de manglar (Cortés, 1997;Espinoza et al, 2020;Wehrtmann & Cortés, 2009). A pesar de su importancia ecológica, los estudios de la ictiofauna en el AMM-BSE se han limitado a observaciones puntuales o se han enfocado en otras zonas del Pacífico Norte de Costa Rica (Angulo et al, 2021;Arias-Godínez et al, 2019;Eisele et al, 2020;Espinoza & Salas, 2005;Suárez et al, 2021). Además, el AMM-BSE se encuentra en una región de afloramiento costero, en la cual se dan cambios estacionales en la productividad y condiciones ambientales, producto de los fuertes vientos alisos, lo cual a su vez puede influir en la composición de especies a lo largo del año (Eisele et al, 2020;Fiedler, 2002;Stuhldreier et al, 2015a).…”

“…A pesar de su importancia ecológica, los estudios de la ictiofauna en el AMM-BSE se han limitado a observaciones puntuales o se han enfocado en otras zonas del Pacífico Norte de Costa Rica (Angulo et al, 2021;Arias-Godínez et al, 2019;Eisele et al, 2020;Espinoza & Salas, 2005;Suárez et al, 2021). Además, el AMM-BSE se encuentra en una región de afloramiento costero, en la cual se dan cambios estacionales en la productividad y condiciones ambientales, producto de los fuertes vientos alisos, lo cual a su vez puede influir en la composición de especies a lo largo del año (Eisele et al, 2020;Fiedler, 2002;Stuhldreier et al, 2015a).…”

Synopsis of global fresh and brackish water occurrences of the bull shark Carcharhinus leucas Valenciennes, 1839 (Pisces: Carcharhinidae), with comments on distribution and habitat use

“…Possibly, C. leu cas temporarily and occasionally reaches as far north as the Californian waters of the United States. The distribution of C. leucas in the eastern Pacific includes the coastal waters of Mexico, Guatemala, El Salvador, Honduras, Nicaragua, Costa Rica, Panama, Colombia, Ecuador, and Peru (chirichiGno 1974;lóPez & BussinG 1982;díaz 1984;BussinG & lóPez 1993;martinez 1999;meJía-falla et al 2007;Jacquet et al 2008;erisman et al 2011;meJíafalla & navia 2019;eisele et al 2021;González-acosta et al 2021). This distribution corresponds exactly to the eastern Pacific Tropical (Panamanian) Faunal Region as defined by BriGGs (1961).…”

The devastating duo: bycatch and climate change hit the Atlantic wolffish Anarhichas lupus

“…The catastrophic effect of climate change on marine life has been recognised by scientists internationally and is supported by a burgeoning peer reviewed evidence base (Wepener, 2020). In 2021, the Journal of Fish Biology published its largest number of climate change related manuscripts, topics including reef fish assemblages (Eisele et al, 2021), thermal strategies of epaulette shark (Hemiscyllium ocellatum) (Nay et al, 2021) and growth rate of Japanese Spanish mackerel (Scomberomorus niphonius) (Jin et al, 2021), to name a few.In September 2020, growing concern over the impact of climate change on aquatic environments culminated in the 'World Aquatic Societies Statement On Climate Change'. A staggering 111 aquatic scientific societies, representing more than 80,000 scientists, issued the statement, with a plea to mitigate against further degradation caused by man-made climate change (Bonar, 2021).…”

“…The catastrophic effect of climate change on marine life has been recognised by scientists internationally and is supported by a burgeoning peer reviewed evidence base (Wepener, 2020). In 2021, the Journal of Fish Biology published its largest number of climate change related manuscripts, topics including reef fish assemblages (Eisele et al, 2021), thermal strategies of epaulette shark (Hemiscyllium ocellatum) (Nay et al, 2021) and growth rate of Japanese Spanish mackerel (Scomberomorus niphonius) (Jin et al, 2021), to name a few.…”