Characterizing Community Structure of Benthic Infauna From the Continental Slope of the Southern California Bight

Infauna are an ecologically important component of marine benthic ecosystems and are the most common faunal assemblage used to assess habitat quality. Compared to the shallower waters of the continental shelf, less is known about the benthic fauna from the continental slope, especially how the commu...

Full description

Bibliographic Details
Main Authors: David J. Gillett, Lisa Gilbane, Kenneth C. Schiff
Format: Article
Language:English
Published: Frontiers Media S.A. 2021-01-01
Series:Frontiers in Marine Science
Subjects:
Online Access:https://www.frontiersin.org/articles/10.3389/fmars.2021.605858/full
_version_ 1818603237992824832
author David J. Gillett
Lisa Gilbane
Kenneth C. Schiff
author_facet David J. Gillett
Lisa Gilbane
Kenneth C. Schiff
author_sort David J. Gillett
collection DOAJ
description Infauna are an ecologically important component of marine benthic ecosystems and are the most common faunal assemblage used to assess habitat quality. Compared to the shallower waters of the continental shelf, less is known about the benthic fauna from the continental slope, especially how the communities are structured by natural gradients and anthropogenic stressors. The present study was conceived to rectify these data gaps and characterize the natural, baseline structure of the benthic infauna of the upper continental slope (200–100 m) of the Southern California Bight. We aggregated benthic infauna, sediment composition, and sediment chemistry data from different surveys across the Southern California Bight region (750 samples from 347 sites) collected between 1972 and 2016. We defined 208 samples to be in reference condition based upon sediment chemistry and proximity to known anthropogenic disturbances. Cluster analysis of the reference samples was used to identify distinct assemblages and the abiotic characteristics associated with each cluster were then used to define habitat characteristics for each assemblage. Three habitats were identified, delineated by geography, depth, and sediment composition. Across the habitats, there were detectable changes in community composition of the non-disturbed fauna through time. However, the uniqueness of the habitats was persistent, as the fauna from each habitat remained taxonomically distinct from irrespective of the decade of their collection. Within each habitat, subtle, assemblage-scale responses to disturbance could be detected, but no consistent patterns could be identified among the component taxa. As with the non-disturbed samples, there were compositional changes in the fauna of the disturbed samples through time. Despite the changes, fauna from disturbed and non-disturbed samples remained taxonomically distinct from each other within each decade of the dataset. After considering both the spatial and temporal patterns in the fauna of slope ecosystem, it became apparent that there was a high degree of stochasticity in the taxonomic organization of all three habitats. This would suggest that the benthic fauna from these communities may be neutrally organized, which in turn poses interesting challenges for future development of condition assessment tools based upon the benthic fauna in these habitats.
first_indexed 2024-12-16T13:19:59Z
format Article
id doaj.art-1c4a14b2a3b74f229a6229b27e88ad76
institution Directory Open Access Journal
issn 2296-7745
language English
last_indexed 2024-12-16T13:19:59Z
publishDate 2021-01-01
publisher Frontiers Media S.A.
record_format Article
series Frontiers in Marine Science
spelling doaj.art-1c4a14b2a3b74f229a6229b27e88ad762022-12-21T22:30:22ZengFrontiers Media S.A.Frontiers in Marine Science2296-77452021-01-01810.3389/fmars.2021.605858605858Characterizing Community Structure of Benthic Infauna From the Continental Slope of the Southern California BightDavid J. Gillett0Lisa Gilbane1Kenneth C. Schiff2Southern California Coastal Water Research Project, Costa Mesa, CA, United StatesEnvironmental Analysis Section, Bureau of Ocean Energy Management, Camarillo, CA, United StatesSouthern California Coastal Water Research Project, Costa Mesa, CA, United StatesInfauna are an ecologically important component of marine benthic ecosystems and are the most common faunal assemblage used to assess habitat quality. Compared to the shallower waters of the continental shelf, less is known about the benthic fauna from the continental slope, especially how the communities are structured by natural gradients and anthropogenic stressors. The present study was conceived to rectify these data gaps and characterize the natural, baseline structure of the benthic infauna of the upper continental slope (200–100 m) of the Southern California Bight. We aggregated benthic infauna, sediment composition, and sediment chemistry data from different surveys across the Southern California Bight region (750 samples from 347 sites) collected between 1972 and 2016. We defined 208 samples to be in reference condition based upon sediment chemistry and proximity to known anthropogenic disturbances. Cluster analysis of the reference samples was used to identify distinct assemblages and the abiotic characteristics associated with each cluster were then used to define habitat characteristics for each assemblage. Three habitats were identified, delineated by geography, depth, and sediment composition. Across the habitats, there were detectable changes in community composition of the non-disturbed fauna through time. However, the uniqueness of the habitats was persistent, as the fauna from each habitat remained taxonomically distinct from irrespective of the decade of their collection. Within each habitat, subtle, assemblage-scale responses to disturbance could be detected, but no consistent patterns could be identified among the component taxa. As with the non-disturbed samples, there were compositional changes in the fauna of the disturbed samples through time. Despite the changes, fauna from disturbed and non-disturbed samples remained taxonomically distinct from each other within each decade of the dataset. After considering both the spatial and temporal patterns in the fauna of slope ecosystem, it became apparent that there was a high degree of stochasticity in the taxonomic organization of all three habitats. This would suggest that the benthic fauna from these communities may be neutrally organized, which in turn poses interesting challenges for future development of condition assessment tools based upon the benthic fauna in these habitats.https://www.frontiersin.org/articles/10.3389/fmars.2021.605858/fullmacrobenthosstressor responseneutral community organizationreference conditionsbioassessment
spellingShingle David J. Gillett
Lisa Gilbane
Kenneth C. Schiff
Characterizing Community Structure of Benthic Infauna From the Continental Slope of the Southern California Bight
Frontiers in Marine Science
macrobenthos
stressor response
neutral community organization
reference conditions
bioassessment
title Characterizing Community Structure of Benthic Infauna From the Continental Slope of the Southern California Bight
title_full Characterizing Community Structure of Benthic Infauna From the Continental Slope of the Southern California Bight
title_fullStr Characterizing Community Structure of Benthic Infauna From the Continental Slope of the Southern California Bight
title_full_unstemmed Characterizing Community Structure of Benthic Infauna From the Continental Slope of the Southern California Bight
title_short Characterizing Community Structure of Benthic Infauna From the Continental Slope of the Southern California Bight
title_sort characterizing community structure of benthic infauna from the continental slope of the southern california bight
topic macrobenthos
stressor response
neutral community organization
reference conditions
bioassessment
url https://www.frontiersin.org/articles/10.3389/fmars.2021.605858/full
work_keys_str_mv AT davidjgillett characterizingcommunitystructureofbenthicinfaunafromthecontinentalslopeofthesoutherncaliforniabight
AT lisagilbane characterizingcommunitystructureofbenthicinfaunafromthecontinentalslopeofthesoutherncaliforniabight
AT kennethcschiff characterizingcommunitystructureofbenthicinfaunafromthecontinentalslopeofthesoutherncaliforniabight