Quantitative ecology reveals scale-dependent structural processes of the Antarctic benthos through time
type: CreativeWork
description: Modern day benthic community composition and distribution in the Southern Ocean are influenced by a variety of environmental and evolutionary factors across different spatial scales. Depth, temperature, salinity, and sea ice impact community structure at large spatial scales (e.g., > 60 km). Far less is known about the interactions between taxa and environment at smaller scales, particularly due to the difficulties in collecting polar data. The study of biodiversity typically requires the direct collection of material, including at the larval stage. However, benthic sampling in the Southern Ocean is extremely challenging, and traditional sampling methods also cannot be deployed in regions of high topographic complexity. Advances in camera technology, such as towed camera systems, have now allowed for extensive observation in previously under-sampled areas. While photographs are single snapshots in time, ecological inferences can be made of the community as a whole, allowing us to make in situ observations of these otherwise difficult to sample ecosystems. In this thesis I explored ecosystem structure in the Weddell Sea across a number of spatial and temporal scales using seabed photographs and fossil collections. I first investigated coexistence mechanisms and competition for two solitary scleractinian cup coral populations at the centimetre scale on the rocky slopes of Powell Basin (~2000 m depth). Using Spatial Point Process Analyses I found that these corals likely produced larvae that settle near their parents, and that the one coral morph changed its reproductive behaviour when sympatric to the other morph. This dispersal plasticity likely allowed for the coexistence of ecologically similar taxa at small spatial scales, thereby enhancing alpha diversity. Next, I examined benthic function at the ecosystem level in two habitats in the Weddell Sea: the rocky slopes of Powell Basin and the shallow muddy bottoms (~450 m water depth) near the Antarctic Peninsula. On …
abstract: Modern day benthic community composition and distribution in the Southern Ocean are influenced by a variety of environmental and evolutionary factors across different spatial scales. Depth, temperature, salinity, and sea ice impact community structure at large spatial scales (e.g., > 60 km). Far less is known about the interactions between taxa and environment at smaller scales, particularly due to the difficulties in collecting polar data. The study of biodiversity typically requires the direct collection of material, including at the larval stage. However, benthic sampling in the Southern Ocean is extremely challenging, and traditional sampling methods also cannot be deployed in regions of high topographic complexity. Advances in camera technology, such as towed camera systems, have now allowed for extensive observation in previously under-sampled areas. While photographs are single snapshots in time, ecological inferences can be made of the community as a whole, allowing us to make in situ observations of these otherwise difficult to sample ecosystems. In this thesis I explored ecosystem structure in the Weddell Sea across a number of spatial and temporal scales using seabed photographs and fossil collections. I first investigated coexistence mechanisms and competition for two solitary scleractinian cup coral populations at the centimetre scale on the rocky slopes of Powell Basin (~2000 m depth). Using Spatial Point Process Analyses I found that these corals likely produced larvae that settle near their parents, and that the one coral morph changed its reproductive behaviour when sympatric to the other morph. This dispersal plasticity likely allowed for the coexistence of ecologically similar taxa at small spatial scales, thereby enhancing alpha diversity. Next, I examined benthic function at the ecosystem level in two habitats in the Weddell Sea: the rocky slopes of Powell Basin and the shallow muddy bottoms (~450 m water depth) near the Antarctic Peninsula. On …
author: Khan, Tasnuva Ming
language: eng
keywords: antarctica, community ecology, mass extinction, metacommunity analyses, network analyses, photographic survey, scleractinian corals, Spatial Point Process Analyses
license: https://www.repository.cam.ac.uk/bitstreams/5b6106c6-a175-47d8-b47e-a966626b5f53/download
license: http://purl.org/NET/rdflicense/allrightsreserved
date published: 2025-03-20
date modified: 2026-07-22T22:24:25Z
provider: Cambridge University
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University of Cambridge

PropertyValue
property ID: DOI
value: 10.17863/CAM.122105