Seasonal changes in fish assemblage structure at a shallow seamount in the Gulf of California
- Published
- Accepted
- Subject Areas
- Biodiversity, Ecology, Marine Biology
- Keywords
- Seamount, marine ecology, biodiversity, underwater visual census, marine biology, community ecology, oceanography, fish assemblage, Gulf of California, Sea of Cortez
- Copyright
- © 2016 Jorgensen et al.
- Licence
- This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, reproduction and adaptation in any medium and for any purpose provided that it is properly attributed. For attribution, the original author(s), title, publication source (PeerJ Preprints) and either DOI or URL of the article must be cited.
- Cite this article
- 2016. Seasonal changes in fish assemblage structure at a shallow seamount in the Gulf of California. PeerJ Preprints 4:e2303v1 https://doi.org/10.7287/peerj.preprints.2303v1
Abstract
Seamounts have generally been identified as locations that can promote elevated productivity, biomass and predator biodiversity. These properties attract seamount-associated fisheries where elevated harvests can be obtained relative to surrounding areas. There exists large variation in the geological and oceanographic environment among the thousands of locations that fall within the broad definition of seamount. Global seamount surveys have revealed that not all seamounts are hotspots of biodiversity, and there remains a strong need to understand the mechanisms that underlie variation in species richness observed. We examined the process of fish species assembly at El Bajo Espiritu Santo (EBES) seamount in the Gulf of California over a five-year study period. To effectively quantify the relative abundance of fast-moving and schooling fishes in a ‘blue water’ habitat, we developed a simplified underwater visual census (UVC) methodology and analysis framework suitable for this setting and applicable to future studies in similar environments. We found correlations between seasonally changing community structure and variability in oceanographic conditions. Individual species responses to thermal habitat at EBES revealed three distinct assemblages, a ‘summer assemblage’ tracking warmer overall temperature, a ‘winter assemblage’ correlated with cooler temperature, and a ‘year-round assemblage’ with no significant response to temperature. Species richness was greatest in spring, when cool and warm water masses stratified the water column and a greater number of species from all three assemblages co-occurred. We discuss our findings in the context of potential mechanisms that could account for predator biodiversity at shallow seamounts.
Author Comment
This is a submission to PeerJ for review.
Supplemental Information
Microsoft Word - Supplemental Table S1.doc Table S1
Microsoft Word - Supplemental Table S1.doc Supplemental Table S1. Log likelihood and Chi-square statistical probabilities for multiple logistic regression of abundance, using ordinal values on sea surface temperature (SST) and subsurface temperature (T30) for 17 species occurring at EBES.