Importance of ice algae versus phytoplankton in the diet of megabenthic organisms under contrasting sea ice conditions (Canadian Arctic): a dual biochemical approach (SIA and HBIs)

The effects of global warming are most pronounced at high latitudes and are a threat to primary productivity patterns and, in particular, to sea ice algae. Here, we investigated the importance of ice algae in the diet of megabenthic organisms belonging to several feeding guilds across several locati...

Full description

Saved in:
Bibliographic Details
Main Authors: Thibaud Combaz, Ursula Witte, Thomas A. Brown, Philippe Archambault
Format: Article
Language:English
Published: Frontiers Media S.A. 2025-06-01
Series:Frontiers in Marine Science
Subjects:
Online Access:https://www.frontiersin.org/articles/10.3389/fmars.2025.1574292/full
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1849407219549863936
author Thibaud Combaz
Thibaud Combaz
Ursula Witte
Thomas A. Brown
Philippe Archambault
author_facet Thibaud Combaz
Thibaud Combaz
Ursula Witte
Thomas A. Brown
Philippe Archambault
author_sort Thibaud Combaz
collection DOAJ
description The effects of global warming are most pronounced at high latitudes and are a threat to primary productivity patterns and, in particular, to sea ice algae. Here, we investigated the importance of ice algae in the diet of megabenthic organisms belonging to several feeding guilds across several locations in the Canadian Arctic characterised by different sea ice conditions using two biochemical approaches i.e., stable isotope and highly branched isoprenoid (HBI) lipids analysis. In addition, the short-term ingestion (gut contents) versus mid to long-term assimilation (tissues) of carbon were investigated to depict momentary condition in the present and the recent past. Our results show firstly that, as soon as the ice breaks up, ice algae accounts for a high proportion of the organic matter deposited to the seafloor and can provide a substantial carbon input to benthic communities for a long period of time (up to 79 days after sea ice break up in our case). Overall, organisms responded rapidly and efficiently to this pulse of fresh organic matter but trends in resource utilisation (quality and quantity) were observed based on feeding strategy. Deposit feeders (except those from lasting sea ice cover) and predators/scavengers showed a dominance of ice algae feeding, while suspension feeder showed a stronger reliance on phytoplankton. Finally, the spatial variability in resource utilisation by ophiuroids is likely related to area’s specificities (e.g., primary production, ice break-up timing, grazer abundance) and highlighted their ability to adapt to available food by switching their feeding types. Our data show that sympagic (ice-associated) carbon represents a significant proportion of the carbon ingested by the megabenthic organisms in the Canadian Arctic during spring/summer but appears to be highly variable depending on sea ice conditions and availability (e.g., patchiness, depth) on the seafloor. Overall, the ongoing decline in seasonal sea ice could alter the functioning and dynamic of the benthic food web in the Canadian Arctic if certain feeding types (e.g., deposit feeders) are unable to adapt to a change in primary productivity patterns.
format Article
id doaj-art-e2de283871934723a150e72d4e09b7f1
institution Kabale University
issn 2296-7745
language English
publishDate 2025-06-01
publisher Frontiers Media S.A.
record_format Article
series Frontiers in Marine Science
spelling doaj-art-e2de283871934723a150e72d4e09b7f12025-08-20T03:36:08ZengFrontiers Media S.A.Frontiers in Marine Science2296-77452025-06-011210.3389/fmars.2025.15742921574292Importance of ice algae versus phytoplankton in the diet of megabenthic organisms under contrasting sea ice conditions (Canadian Arctic): a dual biochemical approach (SIA and HBIs)Thibaud Combaz0Thibaud Combaz1Ursula Witte2Thomas A. Brown3Philippe Archambault4Oceanlab, School of Biological Sciences, University of Aberdeen, Cruickshank Building, United KingdomTakuvik International Research Laboratory, CNRS/Sorbonne université/Université Laval, Laval, QC, CanadaOceanlab, School of Biological Sciences, University of Aberdeen, Cruickshank Building, United KingdomBiogeochemistry Research Centre, School of Geography, Earth and Environmental Sciences, Plymouth University, Plymouth, United KingdomTakuvik International Research Laboratory, CNRS/Sorbonne université/Université Laval, Laval, QC, CanadaThe effects of global warming are most pronounced at high latitudes and are a threat to primary productivity patterns and, in particular, to sea ice algae. Here, we investigated the importance of ice algae in the diet of megabenthic organisms belonging to several feeding guilds across several locations in the Canadian Arctic characterised by different sea ice conditions using two biochemical approaches i.e., stable isotope and highly branched isoprenoid (HBI) lipids analysis. In addition, the short-term ingestion (gut contents) versus mid to long-term assimilation (tissues) of carbon were investigated to depict momentary condition in the present and the recent past. Our results show firstly that, as soon as the ice breaks up, ice algae accounts for a high proportion of the organic matter deposited to the seafloor and can provide a substantial carbon input to benthic communities for a long period of time (up to 79 days after sea ice break up in our case). Overall, organisms responded rapidly and efficiently to this pulse of fresh organic matter but trends in resource utilisation (quality and quantity) were observed based on feeding strategy. Deposit feeders (except those from lasting sea ice cover) and predators/scavengers showed a dominance of ice algae feeding, while suspension feeder showed a stronger reliance on phytoplankton. Finally, the spatial variability in resource utilisation by ophiuroids is likely related to area’s specificities (e.g., primary production, ice break-up timing, grazer abundance) and highlighted their ability to adapt to available food by switching their feeding types. Our data show that sympagic (ice-associated) carbon represents a significant proportion of the carbon ingested by the megabenthic organisms in the Canadian Arctic during spring/summer but appears to be highly variable depending on sea ice conditions and availability (e.g., patchiness, depth) on the seafloor. Overall, the ongoing decline in seasonal sea ice could alter the functioning and dynamic of the benthic food web in the Canadian Arctic if certain feeding types (e.g., deposit feeders) are unable to adapt to a change in primary productivity patterns.https://www.frontiersin.org/articles/10.3389/fmars.2025.1574292/fullsea ice algaephytoplanktonHBIsstable isotopessympagic-benthic couplingCanadian Arctic
spellingShingle Thibaud Combaz
Thibaud Combaz
Ursula Witte
Thomas A. Brown
Philippe Archambault
Importance of ice algae versus phytoplankton in the diet of megabenthic organisms under contrasting sea ice conditions (Canadian Arctic): a dual biochemical approach (SIA and HBIs)
Frontiers in Marine Science
sea ice algae
phytoplankton
HBIs
stable isotopes
sympagic-benthic coupling
Canadian Arctic
title Importance of ice algae versus phytoplankton in the diet of megabenthic organisms under contrasting sea ice conditions (Canadian Arctic): a dual biochemical approach (SIA and HBIs)
title_full Importance of ice algae versus phytoplankton in the diet of megabenthic organisms under contrasting sea ice conditions (Canadian Arctic): a dual biochemical approach (SIA and HBIs)
title_fullStr Importance of ice algae versus phytoplankton in the diet of megabenthic organisms under contrasting sea ice conditions (Canadian Arctic): a dual biochemical approach (SIA and HBIs)
title_full_unstemmed Importance of ice algae versus phytoplankton in the diet of megabenthic organisms under contrasting sea ice conditions (Canadian Arctic): a dual biochemical approach (SIA and HBIs)
title_short Importance of ice algae versus phytoplankton in the diet of megabenthic organisms under contrasting sea ice conditions (Canadian Arctic): a dual biochemical approach (SIA and HBIs)
title_sort importance of ice algae versus phytoplankton in the diet of megabenthic organisms under contrasting sea ice conditions canadian arctic a dual biochemical approach sia and hbis
topic sea ice algae
phytoplankton
HBIs
stable isotopes
sympagic-benthic coupling
Canadian Arctic
url https://www.frontiersin.org/articles/10.3389/fmars.2025.1574292/full
work_keys_str_mv AT thibaudcombaz importanceoficealgaeversusphytoplanktoninthedietofmegabenthicorganismsundercontrastingseaiceconditionscanadianarcticadualbiochemicalapproachsiaandhbis
AT thibaudcombaz importanceoficealgaeversusphytoplanktoninthedietofmegabenthicorganismsundercontrastingseaiceconditionscanadianarcticadualbiochemicalapproachsiaandhbis
AT ursulawitte importanceoficealgaeversusphytoplanktoninthedietofmegabenthicorganismsundercontrastingseaiceconditionscanadianarcticadualbiochemicalapproachsiaandhbis
AT thomasabrown importanceoficealgaeversusphytoplanktoninthedietofmegabenthicorganismsundercontrastingseaiceconditionscanadianarcticadualbiochemicalapproachsiaandhbis
AT philippearchambault importanceoficealgaeversusphytoplanktoninthedietofmegabenthicorganismsundercontrastingseaiceconditionscanadianarcticadualbiochemicalapproachsiaandhbis