scholarly journals Distribution of Vulnerable Marine Ecosystems at the South Sandwich Islands: Results From the Blue Belt Discovery Expedition 99 Deep-Water Camera Surveys

2021 ◽  
Vol 8 ◽  
Author(s):  
Anna-Leena Downie ◽  
Rui P. Vieira ◽  
Oliver T. Hogg ◽  
Chris Darby
Keyword(s):  
Marine Protected Area ◽  
Benthic Communities ◽  
Marine Ecosystem ◽  
Latitudinal Gradients ◽  
The South ◽  
Indicator Taxa ◽  
Scotia Sea ◽  
Benthic Environment ◽  
South Sandwich Islands ◽  
A Chain

The South Sandwich Islands (SSI) are a chain of volcanic islands located to the east of the Scotia Sea, approximately 700 km south-east of South Georgia. To date, knowledge of the SSI benthic environment remains limited. In this context, the Blue Belt Programme conducted a scientific survey in the SSI Marine Protected Area (MPA) during February/March 2019 to examine the biodiversity and distribution of benthic communities and their potential vulnerability to licensed longline research fisheries. Here we report results from analysis of multibeam echosounder (MBES) data and drop camera imagery data collected in selected locations around the SSI. A total of eight vulnerable marine ecosystem (VME) indicator morphotaxa were mapped along the slopes of the SSI, showing a substantial variation in taxon composition and frequency of occurrence, both along bathymetric and latitudinal gradients. Our results suggest that VME indicator taxa are mostly restricted to waters shallower than 700 m. As such, based on our present understanding of the region’s benthic environment the MPA, as currently established, offers effective protection for the majority of the VME indicator taxa.

scholarly journals Macrobenthic Assessment of the South Sandwich Islands Reveals a Biogeographically Distinct Polar Archipelago

2021 ◽  
Vol 8 ◽  
Author(s):  
Oliver T. Hogg ◽  
Anna-Leena Downie ◽  
Rui P. Vieira ◽  
Chris Darby
Keyword(s):  
Marine Protected Areas ◽  
Marine Protected Area ◽  
Benthic Fauna ◽  
Biodiversity Hotspot ◽  
The South ◽  
South Georgia ◽  
The World ◽  
Benthic Environment ◽  
South Sandwich Islands ◽  
Neighbouring Island

The sub-Antarctic South Sandwich Islands forms part of one of the largest marine protected areas (MPAs) in the world. Whilst the neighbouring island of South Georgia is known to be a biodiversity hotspot, very little was known about the benthic biodiversity or biogeography of the South Sandwich Islands. Here we present findings from the first biophysical assessment of this polar archipelago. Using open-access datasets, alongside results from a recent UK Government-funder Blue Belt expedition to the region, we assess how the island’s biodiversity is structured spatially and taxonomically and how this is driven by environmental factors. The South Sandwich Islands are shown to be both biologically rich, and biogeographically distinct from their neighbouring provinces. A gradient forest approach was used to map the archipelago’s benthic habitats which, based on the functional composition of benthic fauna and environmental characterisation of the benthic environment, demonstrated a distinct biogeographical north-south divide. This faunal and environmental discontinuity between the South Sandwich Islands and the rest of the MPA and between the different islands of the archipelago itself, highlights the importance of the zoned protection across the South Georgia and South Sandwich Islands Marine Protected Area.

Volcanic features and the hydrological setting of Southern Thule, South Sandwich Islands

2008 ◽  
Vol 20 (3) ◽  
pp. 301-308 ◽  
Author(s):  
Claire S. Allen ◽  
John L. Smellie
Keyword(s):  
High Resolution ◽  
Warming Trend ◽  
Hydrothermal Activity ◽  
The South ◽  
Scotia Sea ◽  
Ice Caps ◽  
Low Salinity ◽  
Salinity Data ◽  
South Sandwich Islands ◽  
Salinity Water

AbstractThis paper provides new observations of volcanic features and hydrological characteristics in and around Southern Thule, the southernmost group of islands in the South Sandwich Islands, including the first high-resolution bathymetric image of the Douglas Strait caldera. The South Sandwich Islands are the summits of several very large subduction-related volcanoes constructed at the eastern boundary of the Scotia Sea. Observations of the islands are scarce owing to their remote location and they are only rarely visited, yet the area is an active volcanic arc that is rapidly changing as a result of eruptions, including one (on Montagu Island) that has been ongoing for six years and is creating new land. The three islands that make up Southern Thule are morphologically different, and they illustrate different stages in the construction and evolution of islands in the South Sandwich group. We present the results of an acoustic and hydrographic survey that resulted in the first high-resolution, multibeam ‘swath’ image of the submarine Douglas Strait caldera. The results confirm the presence of a large sediment mound (c. 1000 m3 in volume) on the floor of the Douglas Strait caldera related to a flank collapse of Thule Island. The image also shows an extensive arcuate fault structure, interpreted as evidence that the caldera is nested, and its geomorphological freshness suggests that it is a very young feature that formed conceivably in the last few decades or centuries. The bathymetric image also reveals at least three cone- or mound-like structures within the caldera that may relate to renewed post-caldera volcanism (as pyroclastic cones and/or pillow mounds). Recently formed cones and faults associated with caldera rims are often associated with hydrothermal activity. However, temperature and salinity data collected within the caldera do not yet show any evidence of hydrothermal venting. The ocean surrounding Southern Thule has a prominent surface layer of low salinity water that is probably caused by a high meltwater flux derived from ice caps on the islands. This flux may have been enhanced by the recent warming trend observed in the Antarctic Peninsula, although volcano-related geothermal melting in the ice-filled Thule Island caldera may also contribute to the meltwater flux.

scholarly journals The influence of environmental setting on the community ecology of Ediacaran organisms

2019 ◽  
Author(s):  
Emily G. Mitchell ◽  
Nikolai Bobkov ◽  
Natalia Bykova ◽  
Alavya Dhungana ◽  
Anton Kolesnikov ◽  
...  
Keyword(s):  
Community Ecology ◽  
Shallow Water ◽  
Deep Water ◽  
Benthic Communities ◽  
Bedding Plane ◽  
Depositional Environments ◽  
Time Interval ◽  
Benthic Environment ◽  
A Chain ◽  
Broad Scale

AbstractThe broad-scale environment plays a substantial role in shaping modern marine ecosystems, but the degree to which palaeocommunities were influenced by their environment is unclear. To investigate how broad-scale environment influenced the community ecology of early animal ecosystems we employed spatial point process analyses to examine the community structure of seven bedding-plane assemblages of late Ediacaran age (558–550 Ma), drawn from a range of environmental settings and global localities. The studied palaeocommunities exhibit marked differences in the response of their component taxa to sub-metre-scale habitat heterogeneities on the seafloor. Shallow-marine palaeocommunities were heavily influenced by local habitat heterogeneities, in contrast to their deep-water counterparts. Lower species richness in deep-water Ediacaran assemblages compared to shallow-water counterparts across the studied time-interval could have been driven by this environmental patchiness, because habitat heterogeneities correspond to higher diversity in modern marine environments. The presence of grazers and detritivores within shallow-water communities may have promoted local patchiness, potentially initiating a chain of increasing heterogeneity of benthic communities from shallow to deep-marine depositional environments. Our results provide quantitative support for the “Savannah” hypothesis for early animal diversification – whereby Ediacaran diversification was driven by patchiness in the local benthic environment.Author ContributionsE. Mitchell conceived this paper and wrote the first draft. N. Bobkov, A. Kolesnikov, N. Sozonov and D. Grazhdankin collected the data for DS surface. N. Bobkov and N. Sozonov performed the analyses on DS surface. N. Bykova, S. Xiao, and D. Grazhdankin collected the data for WS, KH1 and KH2 surfaces and E. Mitchell performed the analyses. A. Dhungana and A. Liu collected the data for FUN4 and FUN5 surfaces and A. Dhungana performed the analyses. T. Mustill and D. Grazhdankin collected the data for KS and T. Mustill and E. Mitchell performed the analyses. I. Hogarth developed the software for preliminary KS surface analyses. E. Mitchell, N. Bobkov, N. Bykova, A. Dhungana, A. Kolesnikov, A. Liu, S. Xiao and D. Grazhdankin discussed the results and prepared the manuscript.

scholarly journals Developing UAV Monitoring of South Georgia and the South Sandwich Islands’ Iconic Land-Based Marine Predators

2021 ◽  
Vol 8 ◽  
Author(s):  
John Dickens ◽  
Philip R. Hollyman ◽  
Tom Hart ◽  
Gemma V. Clucas ◽  
Eugene J. Murphy ◽  
...  
Keyword(s):  
Marine Mammals ◽  
Marine Protected Area ◽  
Austral Summer ◽  
Elephant Seal ◽  
Southern Elephant Seal ◽  
The South ◽  
Breeding Sites ◽  
South Georgia ◽  
Marine Predators ◽  
South Sandwich Islands

Many remote islands present barriers to effective wildlife monitoring in terms of challenging terrain and frequency of visits. The sub-Antarctic islands of South Georgia and the South Sandwich Islands are home to globally significant populations of seabirds and marine mammals. South Georgia hosts the largest breeding populations of Antarctic fur seals, southern elephant seals and king penguins as well as significant populations of wandering, black-browed and grey-headed albatross. The island also holds important populations of macaroni and gentoo penguins. The South Sandwich Islands host the world’s largest colony of chinstrap penguins in addition to major populations of Adélie and macaroni penguins. A marine protected area was created around these islands in 2012 but monitoring populations of marine predators remains a challenge, particularly as these species breed over large areas in remote and often inaccessible locations. During the 2019/20 austral summer, we trialled the use of an unoccupied aerial vehicle (UAV; drone) to monitor populations of seals, penguins and albatross and here we report our initial findings, including considerations about the advantages and limitations of the methodology. Three extensive southern elephant seal breeding sites were surveyed with complete counts made around the peak pupping date, two of these sites were last surveyed 24 years ago. A total of nine islands, historically recorded as breeding sites for wandering albatross, were surveyed with 144 fledglings and 48 adults identified from the aerial imagery. The UAV was effective at surveying populations of penguins that nest on flat, open terrain, such as Adélie and chinstrap penguin colonies at the South Sandwich Islands, and an extensive king penguin colony on South Georgia, but proved ineffective for monitoring macaroni penguins nesting in tussock habitat on South Georgia as individuals were obscured or hidden by vegetation. Overall, we show that UAV surveys can allow regular and accurate monitoring of these important wildlife populations.

scholarly journals Detection of Ecological Thresholds and Selection of Indicator Taxa for Epibenthic Communities Exposed to Multiple Pressures

2021 ◽  
Vol 8 ◽  
Author(s):  
Laurie Isabel ◽  
David Beauchesne ◽  
Chris McKindsey ◽  
Philippe Archambault
Keyword(s):  
Benthic Communities ◽  
Marine Ecosystem ◽  
Anthropogenic Pressures ◽  
Eastern Canada ◽  
Management Tools ◽  
Indicator Taxa ◽  
Multiple Pressures ◽  
Concentration Threshold ◽  
The Impact ◽  
Epibenthic Communities

The estuary and the Gulf of St. Lawrence (EGSL), eastern Canada form a vast inland sea that is subjected to numerous anthropogenic pressures. Management tools are needed to detect and quantify their effect on benthic communities. The aims of this study are to analyze the spatial distribution of epibenthic communities in the EGSL and quantify the impact of important pressures on them to identify indicator taxa. Epibenthic communities were sampled at 1314 EGSL sites between 2011 and 2018 by bottom trawling. Cluster analyses revealed the presence of six distinct epibenthic communities that seem to be strongly influenced by oxygen concentration. Threshold analyses confirm that oxygen is an important predictor of epibenthic community composition and distribution. A major oxygen threshold is observed around 50–100 μmol O2 L–1, resulting in a shift of community type. At these concentrations and below, opportunistic taxa dominate the community while sensitive taxa are absent or present at very low abundance. Biomass of the latter only starts to increase when oxygen concentrations reach 150 μmol O2 L–1. The species Actinostola callosa, Actinauge cristata, Ctenodiscus crispatus, and Brisaster fragilis were identified as good indicators for detecting this impact threshold forepibenthic communities. This study provides threshold-based indicator species that help to establish and monitor the ecological state of epibenthic communities in a marine ecosystem exposed to multiple pressures.

scholarly journals Combined Abundance of All Vulnerable Marine Ecosystem Indicator Taxa Inadequate as Sole Determiner of Vulnerability, Antarctic Peninsula

2021 ◽  
Vol 8 ◽  
Author(s):  
Susanne J. Lockhart ◽  
John Hocevar
Keyword(s):  
At Risk ◽  
Southern Ocean ◽  
Fisheries Management ◽  
Cold Water ◽  
Benthic Communities ◽  
Marine Ecosystem ◽  
Precautionary Approach ◽  
Indicator Taxa ◽  
Vulnerable Communities ◽  
Antarctic Marine

In order to achieve conservation objectives and preserve the biodiversity of the Southern Ocean, a variety of ecosystems must be protected. This holds especially true for the benthic communities of this region that are characteristically mosaic in their spatial distributions. As such, disparate communities cannot be comprehensively assessed by a single blanket methodology. Herein, evidence appropriate to the diverse characteristics of the communities encountered during a submarine expedition demonstrates the particular vulnerability of four sites that exemplify VMEs as defined by the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) and the UN’s Fisheries and Agriculture Organization (FAO). Three sites are identified as VMEs based on highly significant abundances of indicator taxa. A fourth is identified based on a high density of cold-water coral taxa, many of which were not observed in abundance at the sites that were triggered as vulnerable by a significantly high abundance of all indicator taxa. The VME at this latter site was richly diverse in coral taxa, many of which are considered particularly vulnerable to climate change, as well as critical for their potential for genuine blue carbon sequestration. As of November, 2018, all four sites are now registered with CCAMLR as VMEs and thus, are afforded protection from all bottom fishing activities. However, if consideration isn’t given to the composition and/or diversity of VME indicator taxa present, in addition to overall abundance/density, some of the most vulnerable communities are left at risk. A blanket threshold for all VME taxa adhered to in fisheries management of the Southern Ocean, and other high seas areas, is grossly insufficient. Without taking a more precautionary approach to identifying and protecting VMEs, CCAMLR will not be able to meet its conservation objectives and may even be putting Antarctic fisheries at risk.

Late glacial to Holocene climatic and oceanographic record of sediment facies from the South Scotia Sea off the northern Antarctic Peninsula

2007 ◽  
Vol 54 (21-22) ◽  
pp. 2367-2387 ◽  
Author(s):  
H.I. Yoon ◽  
B.K. Khim ◽  
K.-C. Yoo ◽  
Y.S. Bak ◽  
J.I. Lee
Keyword(s):  
Antarctic Peninsula ◽  
Late Glacial ◽  
The South ◽  
Scotia Sea

scholarly journals Tourists’ perception of marine ecosystem conservation in the Nha Trang Bay Marine Protected Area, Vietnam

Tropics ◽  
2016 ◽  
Vol 24 (4) ◽  
pp. 187-194 ◽  
Author(s):  
Naoko Kaida ◽  
Nguyet Anh Dang
Keyword(s):  
Protected Area ◽  
Marine Protected Area ◽  
Marine Ecosystem ◽  
Ecosystem Conservation ◽  
Nha Trang Bay
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