Reef fish functional composition and metrics reveal spatial differences in three protected islands in the Eastern Pacific

Abstract

Reef fish assemblages in the Eastern Pacific (EP) represent an interesting system to understand how areas with lower diversity respond to multiple factors and their effect on ecosystem functions and services. Among the multiple approaches that have emerged, the evaluation of functional metrics provides an initial comprehension of these relationships. In this context, to better understand reef fish variability in the EP, we evaluated spatial differences in ecological metrics, the composition of fish assemblages, and their relationship with habitat structure in coral communities at 3 islands in Mexico (Marietas, Isabel, and Cleofas). To include a functional approach, we created a functional entity (FE) matrix using species abundance and 6 categorical functional traits; specifically, we calculated ecological metrics that reflect the representation or under-representation of species in the functions or FEs (redundancy and vulnerability) and the rarity in FEs and species and their relationship with habitat structure. Overall, most of the fish FEs in the EP were represented by 1 species (i.e. high vulnerability and low functional redundancy). Despite the low redundancy recorded in the islands, reef fish performed multiple key functions; however, many functions remained rare. Furthermore, both metrics and fish composition showed high variability among sites and islands, but this variability was only partially explained by a few variables of habitat structure (i.e. rugosity). These results, in combination with the unique characteristics of coral communities in the EP, highlight the need to identify the drivers of fish assemblages and their effect on the ecosystem processes and services in order to implement unique management strategies for each island.

The biodiversity of fishes at the Islas Marías Biosphere Reserve, Mexico, as determined by baited remote underwater video

“…In particular, it is necessary to assess the effect of global change and local-scaled anthropogenic threats including but not limited to legal and illegal fishing, sportfishing, and other tourism activities. Additionally, future studies should assess the seasonal and long-term annual variability of fishes at Islas Marías, in relation to seasonal upwelling events, interannual El Niño/Southern Oscillation events, and other oceanographic factors, which may impact fish community assemblages and functional composition (Lopez-Sandoval et al 2009, Morales-de-Anda et al 2020.…”

“…En particular, es necesario evaluar el efecto del cambio global y las amenazas antropogénicas a escala local que incluyen, pero no se limitan a, la pesca legal e ilegal, la pesca deportiva y otras actividades turísticas. Además, los estudios futuros deben evaluar la variabilidad estacional y anual de largo plazo de los peces en las islas Marías, en relación con los eventos de surgencia estacional, los eventos interanuales de El Niño/Oscilación del Sur y otros factores oceanográficos, los cuales pueden afectar la agrupación de las comunidades de peces y la composición funcional (Lopez-Sandoval et al 2009, Morales-de-Anda et al 2020.…”

“…The region is also home to many iconic species such as migratory sharks and sea turtles which are groups of conservation concern (CONANP-SEMARNAT 2010). In recognition of the importance of biodiversity in this region, several islands and archipelagos within the TEP have been the subject of recent conservation efforts (Ketchum and Reyes-Bonilla 1997, Jones 2013, Friedlander et al 2019, Morales-de-Anda et al 2020, while others remain virtually unstudied.…”

“…La región también alberga muchas especies icónicas, como tiburones y tortugas marinas migratorias, que son grupos de interés para la conservación (CONANP-SEMARNAT 2010). En reconocimiento a la importancia de la biodiversidad en esta región, varias islas y archipiélagos dentro del POT han sido el objeto de esfuerzos de conservación recientes (Ketchum y Reyes-Bonilla 1997, Jones 2013, Friedlander et al 2019, Morales-de Anda et al 2020, mientras que otros sitios permanecen prácticamente sin estudiar.…”

Contrasts in ecological assessment and tourism sector perceptions of coral reefs: a case study at Islas Marietas National Park

“…The present study represents a multi-disciplinary approach to address this gap in knowledge at Islas Marietas National Park by investigating changes in live coral cover (LCC) from 2012 to 2022 and whether tourists' and tourism operators' perceptions of the natural environment coincide with the results of ecological monitoring. Live coral cover was selected as a commonly used metric of reef health that can also serve as a proxy for other ecological variables, including the presence of key organisms such as reef fish [21]. Insights about the natural environment from those who work at, visit, or otherwise interact with protected areas are also necessary to understand gaps in understanding and awareness, which can inform management actions and education initiatives.…”