{"id":{"repo_id":"uhi-uk","oai_identifier":"oai:pure.atira.dk:studenttheses/6424ee46-8646-4c7f-8a62-7408b741d522"},"canonical_url":"https://search.dev.ndltd.org/etd/uhi-uk/oai:pure.atira.dk:studenttheses/6424ee46-8646-4c7f-8a62-7408b741d522","repository":{"repo_id":"uhi-uk","name":"University of the Highlands and Islands","base_url":"https://pureadmin.uhi.ac.uk/ws/oai"},"display":{"title":"Investigating the importance of different sources of organic matter as food for the benthos on three Arctic shelves","abstract":"Benthic communities on Arctic shelves are a key component of food webs, nutrient
cycling, and carbon burial. In ice-covered waters, they are fuelled by a complex assemblage
of organic matter from different sources, especially primary production from overlying
pelagic and sympagic (ice-associated) algae, and from terrestrial inputs in areas of high river
run-off. As the Arctic system is undergoing rapid changes, the relative contributions of these
sources of organic matter to benthic food webs are also changing. It is therefore crucial to
understand what fuels the Arctic benthos, to understand how resilient it can be to these
shifting food sources. Three Arctic shelves were studied: the Barents Sea, the Northeast
Greenland Shelf, and the Beaufort Sea Shelf, representing the often-described inflow,
outflow, and interior shelves, respectively. Highly branched isoprenoids – lipid biomarkers
produced with distinct structures in sea ice and the water column – were used to calculate
the ratio of sympagic-to-pelagic organic matter assimilated by the benthos in the Barents Sea
and Northeast Greenland Shelf. In the Barents Sea, the proportion of organic matter from
sympagic sources ranged from 0.4% to 95.8%. In the summer, a strong spatial pattern
(r2=0.754) associated with sea ice duration was found, with the benthic community feeding
on more sympagic organic matter in areas with longer ice cover. In the winter, the benthos
of the Barents Sea fed mostly on pelagic organic matter. On the Northeast Greenland Shelf,
where sea ice cover is much longer (~10 months) sympagic carbon constituted a larger
portion of diets (90%) throughout the study area, and sea ice duration had very little effect.
In the fjords, assimilation of sympagic carbon was higher (93.7%) than on the open shelf
(83.3%), due to the different type of sea ice (land-fast vs drift ice) and nutrient availability.
On the Beaufort Sea Shelf, stable isotopes were used to investigate seasonal and spatial
trophic structure change and terrestrial influence. Benthic trophic structure remained
seasonally quite stable but changed spatially with the strength of pelagic-benthic coupling.
Stronger pelagic-benthic coupling was found in shallower regions and an area of upwelling
and higher primary productivity. Terrestrial influence did not show many spatial or seasonal
variations in the benthos. The results here indicate that sympagic organic matter can be a
temporally and spatially important food source, and that the delivery of different sources of
organic matter to the Arctic benthos is not controlled by the same environmental factors on
different Arctic shelves. There are still gaps in our understanding of Arctic benthic food
webs, with different methods often showing inconsistent results. Future research should
focus on combining these methods within the same studies, in order to better understand the
roles of different sources of organic matter to the Arctic benthos.","abstract_html":"Benthic communities on Arctic shelves are a key component of food webs, nutrient<br/>cycling, and carbon burial. In ice-covered waters, they are fuelled by a complex assemblage<br/>of organic matter from different sources, especially primary production from overlying<br/>pelagic and sympagic (ice-associated) algae, and from terrestrial inputs in areas of high river<br/>run-off. As the Arctic system is undergoing rapid changes, the relative contributions of these<br/>sources of organic matter to benthic food webs are also changing. It is therefore crucial to<br/>understand what fuels the Arctic benthos, to understand how resilient it can be to these<br/>shifting food sources. Three Arctic shelves were studied: the Barents Sea, the Northeast<br/>Greenland Shelf, and the Beaufort Sea Shelf, representing the often-described inflow,<br/>outflow, and interior shelves, respectively. Highly branched isoprenoids – lipid biomarkers<br/>produced with distinct structures in sea ice and the water column – were used to calculate<br/>the ratio of sympagic-to-pelagic organic matter assimilated by the benthos in the Barents Sea<br/>and Northeast Greenland Shelf. In the Barents Sea, the proportion of organic matter from<br/>sympagic sources ranged from 0.4% to 95.8%. In the summer, a strong spatial pattern<br/>(r2=0.754) associated with sea ice duration was found, with the benthic community feeding<br/>on more sympagic organic matter in areas with longer ice cover. In the winter, the benthos<br/>of the Barents Sea fed mostly on pelagic organic matter. On the Northeast Greenland Shelf,<br/>where sea ice cover is much longer (~10 months) sympagic carbon constituted a larger<br/>portion of diets (90%) throughout the study area, and sea ice duration had very little effect.<br/>In the fjords, assimilation of sympagic carbon was higher (93.7%) than on the open shelf<br/>(83.3%), due to the different type of sea ice (land-fast vs drift ice) and nutrient availability.<br/>On the Beaufort Sea Shelf, stable isotopes were used to investigate seasonal and spatial<br/>trophic structure change and terrestrial influence. Benthic trophic structure remained<br/>seasonally quite stable but changed spatially with the strength of pelagic-benthic coupling.<br/>Stronger pelagic-benthic coupling was found in shallower regions and an area of upwelling<br/>and higher primary productivity. Terrestrial influence did not show many spatial or seasonal<br/>variations in the benthos. The results here indicate that sympagic organic matter can be a<br/>temporally and spatially important food source, and that the delivery of different sources of<br/>organic matter to the Arctic benthos is not controlled by the same environmental factors on<br/>different Arctic shelves. There are still gaps in our understanding of Arctic benthic food<br/>webs, with different methods often showing inconsistent results. Future research should<br/>focus on combining these methods within the same studies, in order to better understand the<br/>roles of different sources of organic matter to the Arctic benthos.","abstract_has_math":false,"creators":["Cautain, Ivan"],"institution":"University of the Highlands and Islands","degree_name":"Doctor of Philosophy (awarded by UHI)","degree_level":"Doctoral Thesis","degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":["Narayanaswamy, Bhavani","Last, Kim"],"committee_chairs":[],"committee_members":[],"year":2024,"date_issued":"2024-5-9","date_published":"2024-5-9","updated_at":"2026-07-24T05:12:10Z","subjects":[],"languages":["eng"],"rights":[],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["oai:pure.atira.dk:studenttheses/6424ee46-8646-4c7f-8a62-7408b741d522"],"render_values":[{"text":"oai:pure.atira.dk:studenttheses/6424ee46-8646-4c7f-8a62-7408b741d522","href":null,"code":true}]}]},"links":{"outbound_url":"https://pure.uhi.ac.uk/en/studentTheses/6424ee46-8646-4c7f-8a62-7408b741d522","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Narayanaswamy, Bhavani","Last, Kim"]},{"key":"dc:creator","label":"Author","values":["Cautain, Ivan"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2024-5-9"]},{"key":"dc:date.issued","label":"Date","values":["2024-5-9"]},{"key":"dc:publisher.department","label":"Dc Publisher Department","values":["The Scottish Association for Marine Science, Scottish Marine Institute"]},{"key":"dc:publisher.institution","label":"Dc Publisher Institution","values":["University of the Highlands and Islands"]},{"key":"dc:relation.isreferencedby","label":"Dc Relation Isreferencedby","values":["https://pure.uhi.ac.uk/en/studentTheses/6424ee46-8646-4c7f-8a62-7408b741d522"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"dc:type.qualificationlevel","label":"Dc Type Qualificationlevel","values":["Doctoral Thesis"]},{"key":"dc:type.qualificationname","label":"Dc Type Qualificationname","values":["Doctor of Philosophy (awarded by UHI)"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["eng"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["oai:pure.atira.dk:studenttheses/6424ee46-8646-4c7f-8a62-7408b741d522","https://pure.uhi.ac.uk/en/studentTheses/6424ee46-8646-4c7f-8a62-7408b741d522"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["https://pure.uhi.ac.uk/files/56971586/Ivan_Cautain_final_thesis.pdf"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Benthic communities on Arctic shelves are a key component of food webs, nutrient
cycling, and carbon burial. In ice-covered waters, they are fuelled by a complex assemblage
of organic matter from different sources, especially primary production from overlying
pelagic and sympagic (ice-associated) algae, and from terrestrial inputs in areas of high river
run-off. As the Arctic system is undergoing rapid changes, the relative contributions of these
sources of organic matter to benthic food webs are also changing. It is therefore crucial to
understand what fuels the Arctic benthos, to understand how resilient it can be to these
shifting food sources. Three Arctic shelves were studied: the Barents Sea, the Northeast
Greenland Shelf, and the Beaufort Sea Shelf, representing the often-described inflow,
outflow, and interior shelves, respectively. Highly branched isoprenoids – lipid biomarkers
produced with distinct structures in sea ice and the water column – were used to calculate
the ratio of sympagic-to-pelagic organic matter assimilated by the benthos in the Barents Sea
and Northeast Greenland Shelf. In the Barents Sea, the proportion of organic matter from
sympagic sources ranged from 0.4% to 95.8%. In the summer, a strong spatial pattern
(r2=0.754) associated with sea ice duration was found, with the benthic community feeding
on more sympagic organic matter in areas with longer ice cover. In the winter, the benthos
of the Barents Sea fed mostly on pelagic organic matter. On the Northeast Greenland Shelf,
where sea ice cover is much longer (~10 months) sympagic carbon constituted a larger
portion of diets (90%) throughout the study area, and sea ice duration had very little effect.
In the fjords, assimilation of sympagic carbon was higher (93.7%) than on the open shelf
(83.3%), due to the different type of sea ice (land-fast vs drift ice) and nutrient availability.
On the Beaufort Sea Shelf, stable isotopes were used to investigate seasonal and spatial
trophic structure change and terrestrial influence. Benthic trophic structure remained
seasonally quite stable but changed spatially with the strength of pelagic-benthic coupling.
Stronger pelagic-benthic coupling was found in shallower regions and an area of upwelling
and higher primary productivity. Terrestrial influence did not show many spatial or seasonal
variations in the benthos. The results here indicate that sympagic organic matter can be a
temporally and spatially important food source, and that the delivery of different sources of
organic matter to the Arctic benthos is not controlled by the same environmental factors on
different Arctic shelves. There are still gaps in our understanding of Arctic benthic food
webs, with different methods often showing inconsistent results. Future research should
focus on combining these methods within the same studies, in order to better understand the
roles of different sources of organic matter to the Arctic benthos."]},{"key":"dc:title","label":"Title","values":["Investigating the importance of different sources of organic matter as food for the benthos on three Arctic shelves"]}]}],"canonical_facts":{"dc:contributor.advisor":["Narayanaswamy, Bhavani","Last, Kim"],"dc:creator":["Cautain, Ivan"],"dc:date":["2024-5-9"],"dc:date.issued":["2024-5-9"],"dc:description.abstract":["Benthic communities on Arctic shelves are a key component of food webs, nutrient
cycling, and carbon burial. In ice-covered waters, they are fuelled by a complex assemblage
of organic matter from different sources, especially primary production from overlying
pelagic and sympagic (ice-associated) algae, and from terrestrial inputs in areas of high river
run-off. As the Arctic system is undergoing rapid changes, the relative contributions of these
sources of organic matter to benthic food webs are also changing. It is therefore crucial to
understand what fuels the Arctic benthos, to understand how resilient it can be to these
shifting food sources. Three Arctic shelves were studied: the Barents Sea, the Northeast
Greenland Shelf, and the Beaufort Sea Shelf, representing the often-described inflow,
outflow, and interior shelves, respectively. Highly branched isoprenoids – lipid biomarkers
produced with distinct structures in sea ice and the water column – were used to calculate
the ratio of sympagic-to-pelagic organic matter assimilated by the benthos in the Barents Sea
and Northeast Greenland Shelf. In the Barents Sea, the proportion of organic matter from
sympagic sources ranged from 0.4% to 95.8%. In the summer, a strong spatial pattern
(r2=0.754) associated with sea ice duration was found, with the benthic community feeding
on more sympagic organic matter in areas with longer ice cover. In the winter, the benthos
of the Barents Sea fed mostly on pelagic organic matter. On the Northeast Greenland Shelf,
where sea ice cover is much longer (~10 months) sympagic carbon constituted a larger
portion of diets (90%) throughout the study area, and sea ice duration had very little effect.
In the fjords, assimilation of sympagic carbon was higher (93.7%) than on the open shelf
(83.3%), due to the different type of sea ice (land-fast vs drift ice) and nutrient availability.
On the Beaufort Sea Shelf, stable isotopes were used to investigate seasonal and spatial
trophic structure change and terrestrial influence. Benthic trophic structure remained
seasonally quite stable but changed spatially with the strength of pelagic-benthic coupling.
Stronger pelagic-benthic coupling was found in shallower regions and an area of upwelling
and higher primary productivity. Terrestrial influence did not show many spatial or seasonal
variations in the benthos. The results here indicate that sympagic organic matter can be a
temporally and spatially important food source, and that the delivery of different sources of
organic matter to the Arctic benthos is not controlled by the same environmental factors on
different Arctic shelves. There are still gaps in our understanding of Arctic benthic food
webs, with different methods often showing inconsistent results. Future research should
focus on combining these methods within the same studies, in order to better understand the
roles of different sources of organic matter to the Arctic benthos."],"dc:identifier":["oai:pure.atira.dk:studenttheses/6424ee46-8646-4c7f-8a62-7408b741d522","https://pure.uhi.ac.uk/en/studentTheses/6424ee46-8646-4c7f-8a62-7408b741d522"],"dc:identifier.uri":["https://pure.uhi.ac.uk/files/56971586/Ivan_Cautain_final_thesis.pdf"],"dc:language":["eng"],"dc:publisher.department":["The Scottish Association for Marine Science, Scottish Marine Institute"],"dc:publisher.institution":["University of the Highlands and Islands"],"dc:relation.isreferencedby":["https://pure.uhi.ac.uk/en/studentTheses/6424ee46-8646-4c7f-8a62-7408b741d522"],"dc:title":["Investigating the importance of different sources of organic matter as food for the benthos on three Arctic shelves"],"dc:type":["Thesis"],"dc:type.qualificationlevel":["Doctoral Thesis"],"dc:type.qualificationname":["Doctor of Philosophy (awarded by UHI)"]},"updated_at":"2026-07-24T05:12:10Z"}