This study was carried out in the lab to identify species that were collected from three sites (Cape Smellie, Past Clark and Nunatak) on Byers peninsula, Livingston Island South Shetland Islands. The study was to investigate whether the length of time a site had been ice free affected community structure. It was found that Cape Smellie had the highest species richness with sixteen more species than Past Clark and twenty-nine more species than Nunatak. Cape Smellie also had the highest of species and was the site that had been ice free for the longest time period +50 years and the Nunatak samples showed a higher diversity than the other two site samples and is the site that has been ice free for less than 10 years. All of the sites sampled were found to have high numbers of Laevilltorina calignosa, Donacidae, Spinonid, Plathyhelminthe and Amphipods, all of which are highly adaptive species to different stress gradients and are all found worldwide in different types of ecosystems. The main findings in this study suggest that glacial retreat could be a possible cause for the increase in species as the data shows that glacial retreat over time co-insides with the increase in species abundant richness and diversity found on the different sites. There is a good possibility that there are different stages of colonisation by different species being seen in this study, and that location of the sites and the different stress gradients, substrata and exposure are possible controlling factors in the type of species and their found at the different sites. All three study sites had ten of the same species present; amphipods two, three, four, six, and nine, Terrebellida, Nephtyidae, Donacidae, Plathyhelminthe one and two and Enchytraeidae, but as likely, the substrata and different stress gradients i.e. wave intensity tolerance to freezing, the dominant species found on the study sites at Byers peninsula also correspond with the majority of studies carried out on other islands in and around the Antarctic region.
Table of Contents
1. Abstract
2. introduction
3. Methods and materials
3.1. Collection method in the field
3.2. site descriptions
3.3. Method used in lab
3.4. Statically analysis used
3.5. Hypothesis
4. Results
4.1. ANOVA on species richness abundant’s and diversity
4.2. MDS analysis
4.3. ANOSIM
4.4. SIMPER Species that define the communities
5. Discussion
5.1. conclusion
Research Objectives & Key Themes
The study investigates the impact of the duration of ice-free conditions following glacial retreat on the community structure, species richness, and diversity of benthic intertidal assemblages on the Byers Peninsula, Livingston Island. The research aims to determine if there are significant differences in these community parameters across three distinct study sites and whether environmental stress gradients and substrate types act as primary controls for species colonization.
- Analysis of species richness and diversity in relation to glacial retreat time periods.
- Taxonomic identification and community structure comparison across three sites (Cape Smellie, Past Clark, Nunatak).
- Assessment of environmental stress gradients (wave exposure, substrate, temperature) on benthic assemblages.
- Statistical evaluation of feeding strategies and colonization success of Antarctic intertidal species.
Excerpt from the Book
3.3 Method used in lab
The collected Specimens were preserved in 70% ethanol on arrival to the lab. The specimens were empted into trays taking judicial care not to mix the different sites. The specimens were then separated out by eye into workable categories (morphospecies) i.e. amphipods, worms, shells and so on, once this was achieved the different groups were then thoroughly examined under a CETI dissection microscope. Identification of the different species was achieved by a number of identification resources which can be viewed in appendix 3. The specimens were identified to family not genus, this was due to difficulty in finding information on the taxa due to the lack of in-depth information on species from the Antarctic region. Photos were taken of all species for recording purposes. Amphipods were photographed with accompanying notes. This was done because of the wide variety of specimens found, full species list can be viewed in appendix 4. Specimens were then placed in a specimen pot which was labelled with the site where it was found and filled with 70% ethanol for the purpose of preserving the specimen for future work. For those specimens that had excusably large numbers, the count was achieved by sub-sampling the group, counting them then multiplying the rest.
Summary of Chapters
1. Abstract: A brief overview of the research findings, noting that Cape Smellie exhibited the highest species richness and had been ice-free for the longest duration, suggesting a correlation between glacial retreat and colonization.
2. introduction: Explores the harsh environmental conditions of the Antarctic intertidal zones and reviews the existing literature on environmental stress gradients and species dispersal.
3. Methods and materials: Details the field collection processes on Livingston Island, the specific characteristics of the three study sites, and the laboratory protocols used for species identification and data analysis.
4. Results: Presents the statistical findings of the study, including ANOVA, MDS, and SIMPER analyses, demonstrating variations in community composition across the sampled locations.
5. Discussion: Synthesizes the results by linking glacial retreat history, site-specific physical factors, and biological traits like dispersal capability to explain observed community structures.
Keywords
Antarctic, Livingston Island, Byers Peninsula, Benthic, Intertidal, Glacial retreat, Species richness, Community structure, Amphipods, Polychaeta, Donacidae, Environmental gradients, Biodiversity, Colonization, Substrate
Frequently Asked Questions
What is the primary objective of this research?
The research investigates whether the length of time a site has been ice-free due to glacial retreat influences the species richness, diversity, and community structure of intertidal organisms on Livingston Island.
Which specific sites were examined?
The study collected samples from three sites on the Byers Peninsula: Cape Smellie, Past Clark, and the Nunatak site.
What methodology was applied to analyze the species?
The study used taxonomic identification of collected specimens in the lab, followed by statistical methods including ANOVA for richness/diversity, MDS for visual clustering, and SIMPER to define the species contributing most to community similarities.
Did the length of ice-free time affect species richness?
Yes, the results indicate that the site with the longest ice-free duration (Cape Smellie, >50 years) had the highest species richness, whereas sites with more recent glacial retreat showed lower richness.
What are the dominant feeding strategies found in the study?
The intertidal communities observed were dominated by suspension feeders and deposit feeders, which allow species to adapt to the challenging Antarctic conditions.
Why were barnacles and mussels absent from the samples?
The study suggests that the extreme environmental stressors, specifically freezing temperatures and high salinity fluctuations, may prevent these typical coastal colonizers from establishing a presence in this region.
How were amphipods processed in this study?
Amphipods were identified using a dissection microscope, photographed for documentation, and categorized by morphospecies to assess their diversity, which was found to be the highest among all collected groups.
What role does the substrate play in this environment?
The research concludes that the substrate type, ranging from coarse rocks to fine sand, acts as a primary control factor in determining which species can colonize and inhabit a specific coastal area.
- Quote paper
- Andrew Thirdborough (Author), 2011, Community structure and species abundant’s in Antarctic Community’s on Livingston island Byers Peninsula, Munich, GRIN Verlag, https://www.grin.com/document/276442
