TY - JOUR
T1 - Deep-reef fish communities of the Great Barrier Reef shelf-break
T2 - Trophic structure and habitat associations
AU - Sih, Tiffany L.
AU - Daniell, James J.
AU - Bridge, Thomas C.L.
AU - Beaman, Robin J.
AU - Cappo, Mike
AU - Kingsford, Michael J.
PY - 2019/2/1
Y1 - 2019/2/1
N2 - The ecology of habitats along the Great Barrier Reef (GBR) shelf-break has rarely been investigated. Thus, there is little understanding of how associated fishes interact with deeper environments. We examined relationships between deep-reef fish communities and benthic habitat structure. We sampled 48 sites over a large depth gradient (54-260 m) in the central GBR using Baited Remote Underwater Video Stations and multibeam sonar. Fish community composition differed both among multiple shelf-break reefs and habitats within reefs. Epibenthic cover decreased with depth. Deep epibenthic cover included sponges, corals, and macro-algae, with macro-algae present to 194 m. Structural complexity decreased with depth, with more calcified reef, boulders, and bedrock in shallower depths. Deeper sites were flatter and more homogeneous with softer substratum. Habitats were variable within depth strata and were reflected in different fish assemblages among sites and among locations. Overall, fish trophic groups changed with depth and included generalist and benthic carnivores, piscivores, and planktivores while herbivores were rare below 50 m. While depth influenced where trophic groups occurred, site orientation and habitat morphology determined the composition of trophic groups within depths. Future conservation strategies will need to consider the vulnerability of taxa with narrow distributions and habitat requirements in unique shelf-break environments.
AB - The ecology of habitats along the Great Barrier Reef (GBR) shelf-break has rarely been investigated. Thus, there is little understanding of how associated fishes interact with deeper environments. We examined relationships between deep-reef fish communities and benthic habitat structure. We sampled 48 sites over a large depth gradient (54-260 m) in the central GBR using Baited Remote Underwater Video Stations and multibeam sonar. Fish community composition differed both among multiple shelf-break reefs and habitats within reefs. Epibenthic cover decreased with depth. Deep epibenthic cover included sponges, corals, and macro-algae, with macro-algae present to 194 m. Structural complexity decreased with depth, with more calcified reef, boulders, and bedrock in shallower depths. Deeper sites were flatter and more homogeneous with softer substratum. Habitats were variable within depth strata and were reflected in different fish assemblages among sites and among locations. Overall, fish trophic groups changed with depth and included generalist and benthic carnivores, piscivores, and planktivores while herbivores were rare below 50 m. While depth influenced where trophic groups occurred, site orientation and habitat morphology determined the composition of trophic groups within depths. Future conservation strategies will need to consider the vulnerability of taxa with narrow distributions and habitat requirements in unique shelf-break environments.
KW - BRUVS
KW - Deep reefs
KW - Fish-habitat associations
KW - Multibeam bathymetry
KW - Shelf-break habitats
KW - Trophic structure
UR - http://www.scopus.com/inward/record.url?scp=85062719983&partnerID=8YFLogxK
U2 - 10.3390/d11020026
DO - 10.3390/d11020026
M3 - Article
AN - SCOPUS:85062719983
VL - 11
JO - Diversity
JF - Diversity
SN - 1424-2818
IS - 2
M1 - 26
ER -