The first comprehensive description of the biodiversity and biogeography of Antarctic and Sub-Antarctic intertidal communities

Aim To describe the distribution of biodiversity and biogeographical patterns of intertidal organisms in southern temperate and polar waters. We hypothesized that there would be differences in community structure between the Antarctic, which is most affected by ice, and the sub-Antarctic and other neighbouring regions. We also hypothesized that rafting and West Wind Drift will be the significant drivers of biogeographical patterns. Additionally, the size, age, isolation, volcanic or glacial history of a region and the presence of large, beach dwelling, mammals and birds would all play a role in determining the level of biodiversity observed. Location South Atlantic, Indian and Pacific Oceans and the Southern Ocean. Methods We examined all available intertidal records from the Antarctic and sub-Antarctic with additional data from neighbouring regions for comparison and context. We compiled 3902 occurrences of 1416 species of high southern latitude intertidal organisms from 229 locations and used PRIMER 6 to perform multivariate statistical analyses. Results The Antarctic and sub-Antarctic are shown to be distinct biogeographical regions, with patterns driven by a small number of widely distributed species. These wide-ranging molluscs and macroalgae dominate the biogeographical structure of the Southern Ocean intertidal, most likely as a result of rafting in the Antarctic Circumpolar Current. East Antarctic intertidal habitats are potentially isolated by the Ross and Weddell Sea ice shelves but represent a great unknown in this biogeographical scheme. Main Conclusions The view that the Antarctic intertidal is a lifeless desert does not hold true, with Antarctic Peninsula intertidal communities being richer and more diverse than those in southern South America and the sub-Antarctic islands. Changing conditions in the Antarctic and sub-Antarctic intertidal mean that a representative baseline is needed (acquired through standardized and quantitative sampling) to assess future changes and to detect any invasive species

Zoogeographic and Richness Patterns in Southern Ocean Benthos

This thesis describes the large scale biogeographic patterns found in the Southern Ocean benthos. Using SOMBASE and SCAR-MarBIN, the two most comprehensive, georeferenced databases of Antarctic marine biodiversity ever compiled, a range of taxa were investigated but focusing on the Mollusca, Bryozoa and Pycnogonida. Over 8,000 species of marine invertebrates from over 5,000 sites constituting -34,000 records were used in the analyses. The strong faunal links between the Antarctic and South America were confirmed but I found little evidence for a biogeographical relationship between the Antarctic or South America and New Zealand or Tasmania. Regional levels of Southern Ocean endemism proved the influence of the Antarctic Circumpolar Current upon the distribution of Southern Ocean benthos. My study shows the Southern Ocean as a ‘single functional unit’ with no evidence for an earlier proposed biogeographical split between East and West Antarctica. Some general rules on Antarctic benthic biogeography are viable, including species endemism rates of around 50% and a definite distinction between the sub-Antarctic islands influenced by either South America or by New Zealand. In the context of potential shifts in species distribution with climate change I investigated the current ranges of selected Southern Ocean taxa (Mollusca, Amphipoda, Ophiuroidea and Hexacorala), and looked for hotspots of coinciding northern and southern geographic range limits. Southern Patagonia, South Georgia and Kerguelen had the greatest range-limit hotspots. Monitoring range shifts in these key places and taxa will enable us to track the influence and effects of climate change on benthic species distributions in the Southern Ocean

First report of Laternula elliptica in the Antarctic intertidal zone

Many Antarctic marine invertebrates are considered to be highly stenothermal, subjected to loss of functionality at increased temperatures and so at high risk of mortality in a rapidly warming environment. The bivalve Laternula elliptica is often used as a model taxon to test these theories. Here, we report the first instance L. elliptica from an intertidal site. Genetic analysis of the tissue confirms the species identity. A total of seven animals ranging in length from 6 to 85 mm were collected from 3 × 0.25 m2 quadrats of intertidal sediments at St Martha Cove on James Ross Island, Eastern Antarctic Peninsula. Ambient temperatures of 7.5 °C within the sediment and 10 °C (air) were recorded. This raises questions as to the current perception that “many Antarctic marine invertebrates cannot adapt to higher temperatures”

Ostracoda (Crustacea) of Lake Uluabat (Apolyont Gölü) (Bursa Province, Turkey)

AbstractLake Uluabat (Apolyont Gölü), an important bird conservation area, was sampled in summer, autumn, winter and spring, and ostracod species' seasonal and spatial distributions were investigated; many of the taxa collected are useful indicator species for monitoring within-basin conditions. The findings suggest that the Lake Uluabat ecosystem is already substantially degraded. Pollution, coupled with extensive water abstraction for irrigation, have the potential to damage the value of the lake, both commercially (as an inland waters fishery), and as an important site for wetland birds. We suggest that ostracod faunal analysis has value in the ecological study of such sites, particularly where more formal physicochemical monitoring methods are inappropriate or unavailable

Smoking out carcinogens

Smoked foods are becoming increasingly popular and are being produced by large and small food operations, artisan producers, chefs and consumers themselves. Epidemiological studies conducted over a number of decades have linked the consumption of smoked foods with various cancers and these findings have been supported by animal testing. Smoke contains a group of dangerous carcinogens that are responsible for lung cancer in cigarette smokers and implicated as causative agents for colorectal and other human cancers resulting from the consumption of smoked and barbequed food products. This article describes a new innovation in smoke filtration technology that can significantly reduce the presence of carcinogens in aerosol smoke used to produce smoked food products and hence largely remove a group of dangerous chemicals from the food supply

A new methodology for network scale simulation of emerging power line communication standards

This paper presents the development of a new methodology for the simulation of Power Line Communication (PLC) within the popular Electromagnetic Transients Programme-Alternative Transients Programme (EMTP-ATP). As a first application, the comparative performance of the emerging Orthogonal Frequency Division Multiplexing (OFDM) based Prime and G3-PLC narrowband standards is investigated. Models of both standards have been created within the EMTP-ATP and simulations performed using frequency dependent line models and realistic transformer models as terminations. It is observed that both standards are severely affected by the highly frequency selective nature of the MV power line channel and a more considered choice of OFDM parameters may be necessary for optimal performance on MV networks

Multi-indicator conductivity transfer functions for Quaternary palaeoclimate reconstruction

Diatoms (Bacillariophyceae; single-celled algae) and ostracods (Ostracoda; shelled microcrustacea) are known for their sensitivity to salinity. In palaeolimnology, the potential has yet to be tested for quantifying past salinity, lake level, and by inference, climate change, by application of multiple-indicator transfer functions. We used weighted averaging techniques to derive diatom (n=91; r 2 =0.92) and ostracod (n=53; r 2 =0.83) conductivity transfer functions from modern diatom, ostracod and water chemistry data collected in lakes of central, western and northern Turkey. Diatoms were better represented across the full gradient than ostracods, at intermediate levels of conductivity in particular, but both transfer functions were statistically robust. Because transfer functions are not infallible, we further tested the strength and simplicity of salinity response and the potential for identifying characteristic associations of diatom and ostracod taxa in different parts of the salinity gradient, to improve palaeoclimate reconstruction. We identified a subset of 51 samples that contained both diatoms and ostracods, collected at the same time from the same habitat. We used Two-Way Indicator Species Analysis of a combined diatom-ostracod data set, transformed to achieve numerical equivalence, to explore distributions in more detail. A clear ecological threshold was apparent at ~3gl-1 salinity, rather than at 5gl-1, the boundary used by some workers, equating to the oligosaline-mesosaline boundary. Other salinity boundaries were poorly defined, indicating lack of a simple, well-defined salinity response. We did, however, define characteristic associations of taxa, to facilitate the distinction to be drawn between a hydrologically open, fresh lake and an oligosaline lake, in palaeoenvironmental reconstruction. Over the rest of the salinity gradient, we highlighted the potential for the multi-proxy approach to strengthen ostracod-based reconstruction in particular, to overcome the problem of broad apparent tolerance ranges in common halophilic taxa such as Limnocythere inopinata, which often dominate in low-diversity fossil assemblages. The combination of multi-proxy quantitative reconstruction, complemented by qualitative understanding of ecological responses generated by the analysis, remains a powerful tool in Quaternary palaeoclimate research

Biogeography of cephalopods in the Southern Ocean using habitat suitability prediction models

Our understanding of how environmental change in the Southern Ocean will affect marine diversity, habitats and distribution remain limited. The habitats and distributions of Southern Ocean cephalopods are generally poorly understood, and yet such knowledge is necessary for research and conservation management purposes, as well as for assessing the potential impacts of environmental change. We used net-catch data to develop habitat suitability models for 15 of the most common cephalopods in the Southern Ocean. Using modeled habitat suitability, we assessed favorable areas for each species and examined the relationships between species distribution and environmental parameters. The results compared favorably with the known ecology of these species and with spatial patterns from diet studies of squid predators. The individual habitat suitability models were overlaid to generate a “hotspot” index of species richness, which showed higher numbers of squid species associated with various fronts of the Antarctic circumpolar current. Finally, we reviewed the overall distribution of these species and their importance in the diet of Southern Ocean predators. There is a need for further studies to explore the potential impacts of future climate change on Southern Ocean squid