Cargando…
Macrofaunal Patterns in and around du Couedic and Bonney Submarine Canyons, South Australia
Two South Australian canyons, one shelf-incising (du Couedic) and one slope-limited (Bonney) were compared for macrofaunal patterns on the shelf and slope that spanned three water masses. It was hypothesized that community structure would (H1) significantly differ by water mass, (H2) show significan...
Autores principales: | , , , , |
---|---|
Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Public Library of Science
2015
|
Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4664417/ https://www.ncbi.nlm.nih.gov/pubmed/26618354 http://dx.doi.org/10.1371/journal.pone.0143921 |
_version_ | 1782403421140156416 |
---|---|
author | Conlan, Kathleen E. Currie, David R. Dittmann, Sabine Sorokin, Shirley J. Hendrycks, Ed |
author_facet | Conlan, Kathleen E. Currie, David R. Dittmann, Sabine Sorokin, Shirley J. Hendrycks, Ed |
author_sort | Conlan, Kathleen E. |
collection | PubMed |
description | Two South Australian canyons, one shelf-incising (du Couedic) and one slope-limited (Bonney) were compared for macrofaunal patterns on the shelf and slope that spanned three water masses. It was hypothesized that community structure would (H1) significantly differ by water mass, (H2) show significant regional differences and (H3) differ significantly between interior and exterior of each canyon. Five hundred and thirty-one species of macrofauna ≥1 mm were captured at 27 stations situated in depth stratified transects inside and outside the canyons from 100 to1500 m depth. The macrofauna showed a positive relationship to depth in abundance, biomass, species richness and community composition while taxonomic distinctness and evenness remained high at all depths. Biotic variation on the shelf was best defined by variation in bottom water primary production while sediment characteristics and bottom water oxygen, temperature and nutrients defined biotic variation at greater depth. Community structure differed significantly (p<0.01) among the three water masses (shelf-flowing South Australian current, upper slope Flinders current and lower slope Antarctic Intermediate Water) (H1). Although community differences between the du Couedic and Bonney regions were marginally above significance at p = 0.05 (H2), over half of the species captured were unique to each region. This supports the evidence from fish and megafaunal distributions that the du Couedic and Bonney areas are in different bioregions. Overall, the canyon interiors were not significantly different in community composition from the exterior (H3). However, both canyons had higher abundance and/or biomass, increased species dominance, different species composition and coarser sediments near the canyon heads compared to outside the canyons at the same depth (500 m), suggestive of heightened currents within the canyons that influence community composition there. At 1000–1500 m, the canyon interiors were depauperate, typical of V-shaped canyons elsewhere. The large number of species captured, given the relatively low sampling effort and focus on the larger macrofauna, support previous studies that identify the South Australian coast as a high biodiversity area. |
format | Online Article Text |
id | pubmed-4664417 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2015 |
publisher | Public Library of Science |
record_format | MEDLINE/PubMed |
spelling | pubmed-46644172015-12-10 Macrofaunal Patterns in and around du Couedic and Bonney Submarine Canyons, South Australia Conlan, Kathleen E. Currie, David R. Dittmann, Sabine Sorokin, Shirley J. Hendrycks, Ed PLoS One Research Article Two South Australian canyons, one shelf-incising (du Couedic) and one slope-limited (Bonney) were compared for macrofaunal patterns on the shelf and slope that spanned three water masses. It was hypothesized that community structure would (H1) significantly differ by water mass, (H2) show significant regional differences and (H3) differ significantly between interior and exterior of each canyon. Five hundred and thirty-one species of macrofauna ≥1 mm were captured at 27 stations situated in depth stratified transects inside and outside the canyons from 100 to1500 m depth. The macrofauna showed a positive relationship to depth in abundance, biomass, species richness and community composition while taxonomic distinctness and evenness remained high at all depths. Biotic variation on the shelf was best defined by variation in bottom water primary production while sediment characteristics and bottom water oxygen, temperature and nutrients defined biotic variation at greater depth. Community structure differed significantly (p<0.01) among the three water masses (shelf-flowing South Australian current, upper slope Flinders current and lower slope Antarctic Intermediate Water) (H1). Although community differences between the du Couedic and Bonney regions were marginally above significance at p = 0.05 (H2), over half of the species captured were unique to each region. This supports the evidence from fish and megafaunal distributions that the du Couedic and Bonney areas are in different bioregions. Overall, the canyon interiors were not significantly different in community composition from the exterior (H3). However, both canyons had higher abundance and/or biomass, increased species dominance, different species composition and coarser sediments near the canyon heads compared to outside the canyons at the same depth (500 m), suggestive of heightened currents within the canyons that influence community composition there. At 1000–1500 m, the canyon interiors were depauperate, typical of V-shaped canyons elsewhere. The large number of species captured, given the relatively low sampling effort and focus on the larger macrofauna, support previous studies that identify the South Australian coast as a high biodiversity area. Public Library of Science 2015-11-30 /pmc/articles/PMC4664417/ /pubmed/26618354 http://dx.doi.org/10.1371/journal.pone.0143921 Text en © 2015 Conlan et al http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are properly credited. |
spellingShingle | Research Article Conlan, Kathleen E. Currie, David R. Dittmann, Sabine Sorokin, Shirley J. Hendrycks, Ed Macrofaunal Patterns in and around du Couedic and Bonney Submarine Canyons, South Australia |
title | Macrofaunal Patterns in and around du Couedic and Bonney Submarine Canyons, South Australia |
title_full | Macrofaunal Patterns in and around du Couedic and Bonney Submarine Canyons, South Australia |
title_fullStr | Macrofaunal Patterns in and around du Couedic and Bonney Submarine Canyons, South Australia |
title_full_unstemmed | Macrofaunal Patterns in and around du Couedic and Bonney Submarine Canyons, South Australia |
title_short | Macrofaunal Patterns in and around du Couedic and Bonney Submarine Canyons, South Australia |
title_sort | macrofaunal patterns in and around du couedic and bonney submarine canyons, south australia |
topic | Research Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4664417/ https://www.ncbi.nlm.nih.gov/pubmed/26618354 http://dx.doi.org/10.1371/journal.pone.0143921 |
work_keys_str_mv | AT conlankathleene macrofaunalpatternsinandaroundducouedicandbonneysubmarinecanyonssouthaustralia AT curriedavidr macrofaunalpatternsinandaroundducouedicandbonneysubmarinecanyonssouthaustralia AT dittmannsabine macrofaunalpatternsinandaroundducouedicandbonneysubmarinecanyonssouthaustralia AT sorokinshirleyj macrofaunalpatternsinandaroundducouedicandbonneysubmarinecanyonssouthaustralia AT hendrycksed macrofaunalpatternsinandaroundducouedicandbonneysubmarinecanyonssouthaustralia |