Polar Biology最新文献

Ship voyage to Antarctica under stressful conditions impacts the health of expedition members. Measures can be taken to prevent adverse physical and psychological effects. Compared with minimally stressed control subjects in Delhi (India), these effects were investigated in a placebo-controlled study with multi-species probiotics intervention on selected anthropometric, body physiological and biochemical parameters. Total 39 participants volunteered for the study, of which 19 participated in the Antarctic expedition by ship voyage and 20 were the control subjects at Delhi. Participants were randomly divided into two groups and received daily either a probiotic or placebo for 24 days. The results suggest that probiotic intervention during the Antarctic ship voyage reduced sea sickness in probiotic group (10% cases) compared to the placebo group (44% cases). After completion of the ship voyage and intervention, body anthropometric parameters were maintained in the probiotic group. In contrast, significant alterations were observed in the placebo group with respect to their body composition and biochemical parameters as compared to the control group in Delhi. This allows the conclusion that multi-species probiotic intervention may benefit anthropometric and biochemical parameters and reduce the negative influence of stress during the ship voyage. These findings may be useful in improving expedition members’ physiological health and body homeostasis during stressful conditions.

Since the Antarctic continent is not exempt from human disturbances, it is necessary to generate information on the residues of anthropogenic origin in these environments. The main aim of our study was to determine the presence and abundance of anthropogenic residues found around the pygoscelid penguin colony of the Antarctic Specially Protected Area No. 132 "Potter Peninsula" (25 de Mayo/King George Island, South Shetland Islands, Antarctica), in order to contribute with information on the distribution of anthropogenic residues that have been recorded in different regions of the Antarctic Peninsula and the Scotia Arc. A total of 37 anthropogenic elements (821.73 g) were collected between September 2021 and March 2022. According to the type of material, the most abundant were 'various plastic residue' (54.05%) and 'consumer plastic residue' (35.14%). Regarding size, most of the elements had a length between 15 and 30 cm, followed by those with a length < 5 cm, while regarding color, white residues were the most common (n = 9), followed by transparent ones (n = 7). The origin of these residues could be found in fishing, tourism, logistics and scientific activities. It is important to continue monitoring residues to assess potential impacts on biota and the environment.

The Western Antarctic Peninsula supports a diverse assemblage of > 100 described macroalgal species that contribute to the base of coastal food webs, but their contribution to local nearshore food webs is still uncertain across larger spatial scales. The analysis of biomarkers, specifically fatty acids and stable isotopes, offers a tool to clarify the trophic role of Antarctic macroalgae. The aim of this study was to describe the fatty acid profiles and stable isotope values of 31 algal species from three divisions (Chlorophyta—1, Ochrophyta—8, Rhodophyta—22) collected at the same sites for both biomarkers. Of these, 13 species had no previously published fatty acid profiles. Most species were rich in polyunsaturated fatty acids (PUFAs), suggesting they are highly nutritious and could be a resource of essential fatty acids for consumers. This was specifically noticeable in the overall low PUFA ratio (∑ω6/∑ω3 ratio), with low ratios being an indicator of high nutritional quality for consumers. Fatty acid profiles of macroalgae grouped strongly by phylogeny (at the levels of division, order, and family), while stable isotope groupings were more driven by the physiological properties of the species. Specifically, some closely related red algal species exhibited very different stable isotope values based on their carbon concentrating mechanisms, with highly ¹³C-depleted values in several Rhodophyta species. The fact that the two biomarker approaches created different groupings of Antarctic macroalgae collected at the same locations emphasizes that their combined application can be a powerful tool in Antarctic coastal food web studies.

Copepod Boeckella poppei was first recorded in a freshwater body of the Wilhelm Archipelago (Kyiv Peninsula, Maritime Antarctica) in 2008. This crustacean is one of the main consumers of filamentous algae in freshwater Antarctic bodies and is used as an indicator species in freshwater ecosystems. This work aimed to research the current distribution of B. poppei within the Argentine Islands of this archipelago. The second population of this crustacean species was discovered on the Nob Island at the beginning of this research in 2010. Boeckella poppei was also recorded in 33 freshwater bodies of eight other islands in 2020. During the final stage was analyzed the adaptation of B. poppei to the extreme conditions of existence in the freshwater reservoirs of Antarctica and the main ways of the spread of this species over short and long distances in this region of the planet.

Although knowledge of Arctic benthic biodiversity has increased considerably in recent decades, some regions, such as Northeast Greenland, remain poorly studied. The aim of this study was to complement a previous macrofaunal inventory carried out in Young Sound, a High-Arctic fjord in this region (74°N). We sampled shallow benthic assemblages along a small inner/outer fjord gradient, including one station previously prospected two decades ago and three new stations. This sampling strategy revealed highly diversified benthic assemblages (166 species identified on a total sampling area of 1.32 m²), which considerably increases the number of species recorded for the fjord (i.e. 225 species vs 100 previously recorded). The outermost station was dominated in abundance by various assemblages of bivalves, while the middle stations showed greater species evenness, including numerous species of polychaetes, bivalves and crustaceans. The innermost station was dominated by ostracods, gammarid amphipods and tube-dwelling polychaetes. Overall, benthic assemblages varied little between the four stations and the transect as a whole exhibited characteristics typical of outer fjord habitats, reflecting the rather moderate impact of meltwater inputs in this part of the fjord. Finally, trophic plasticity and omnivory were observed in most of the recorded macrobenthic species, highlighting the adaptability of these species to low trophic availability in the ecosystem. Future biodiversity studies will need to explore the innermost and deepest areas to provide a more comprehensive inventory and understanding of the influence of environmental conditions on the structure and functioning of Young Sound benthic habitats.

Integration and coordination among monitoring programs are needed to better assess the impacts of climate change on Arctic marine ecosystems. The use of common indicators and methods could facilitate this comprehensive understanding. We completed a systematic review of published marine research in the western Canadian Arctic from 1962 to 2021 to identify the commonalities in methods and indicators present in assessments of coastal and offshore ecosystems. Most abundant in our sample were indicators addressing the environmental context, followed by indicators concerning trophic webs and biological organisms, and finally indicators associated with anthropogenic stressors and threats. Ship-based studies located far offshore were by far the most common and focused on indicators that characterized the physical environment and lower trophic levels. Commonalities in data collection methods suggest possibilities for standardization among programs for some parameters. Differences and data gaps highlighted areas for future coordination and the potential to integrate among indicators, especially as some indicators may span coastal to offshore ecosystems whereas individual monitoring programs may not. The results of this review could be used to identify and gather data into broad-spanning datasets. Overall, this systematic review highlights opportunities to link indicators and methods among coastal to offshore programs and will therefore facilitate connectivity and coordination of ecological research and monitoring in the western Canadian Arctic.

A wide variety of nipple locations and configurations exist among pinnipeds. Like all marine mammals, pinnipeds can have supernumerary nipples that form in utero. Supernumerary nipples have been documented in several species of pinnipeds, the only taxonomic group of marine mammals with variation in nipple number. We document multiple observations (n = 4) of female Weddell seals (Leptonychotes weddellii) with supernumerary nipples in Erebus Bay, Antarctica, including a female Weddell seal with four nipples that was observed nursing two pups. Intraspecific variation in the number of supernumerary nipples observed included both one and two supernumerary nipples. The majority of the observed supernumerary nipples were nursed on by pups, but lactation was unable to be confirmed. These are the first documented observations of supernumerary nipples in Weddell seals.

Spotted wolffish (Anarhichas minor) is a poorly understood species which is often captured as part of mixed demersal fisheries across its range. Abundance has declined in many regions and there is a need for greater knowledge on its biology. To improve our understanding of reproduction of A. minor, we investigated inter- and intra- annual differences in fecundity, the influence of condition on fecundity and time scale of ovary development. From 2006 to 2021, 150 females A. minor were sampled in Icelandic waters. Of these females, 73 were also used to estimate spawning time together with an additional 334 females from commercial catch and surveys from 2006 to 2023. Backwards extrapolation of oocyte size indicates that vitellogenesis begins in December and is likely completed after 8–10 months. There was no evidence of either intra- or inter-annual differences in fecundity, indicating that downregulation is minimal and that fecundity of A. minor is stable between years. A positive relationship between oocytes size and fish length was detected, while body condition and hepatosomatic index had only a small influence on fecundity in comparison with weight. There was a negative relationship between length and relative fecundity and the exponent of the fecundity–length relationship was lower than exponent of the weight–length relationship. Therefore, total egg production is likely not proportional to the spawning stock biomass of A. minor, and unusually, total egg production would decrease with increasing proportion of larger fish in the population. The spawning season was estimated to be from middle of August to middle of October with peak of spawning in September.

Abstract

Due to climate change and human activities, Antarctic shag populations are experiencing shifts in their distribution range, habitat, and population size. To assess their health, we collected hematological and biochemical of male and female South Georgia shags (Phalacrocorax georgianus) during breeding on Laurie Island, South Orkney Island, Antarctica. Leukocyte profile, heterophil/lymphocyte ratio, hematocrit, and concentrations of glucose, total proteins, cholesterol, and triglycerides were measured. None of the measured metrics showed signs of clinical pathology or disease. Overall, the parameters measured were consistent with those previously reported for other cormorant species. Males had higher protein and cholesterol concentrations, indicating differences in nutritional status between the sexes during reproduction. This study is the first report on blood parameters of South Georgia shags in Antarctica and may be useful for future meta-analyzes comparing blood parameters of different species and geographic areas.

Abstract

Microbial communities in the active layer play a crucial role in the biogeochemical cycles of Antarctic pristine ecosystems. Here, 16S rRNA gene sequencing was used to investigate bacterial communities in active layer of five different geological sites related to the compositional variation of the geological bedrock, including Neogene volcanic or Cretaceous rocks and or marine sediments areas of distinct elevation. Local variations in the thickness of the active layer (50–80 cm) were observed on the Ulu Peninsula, James Ross Island, and the southwest coast of Vega Island, Antarctica during sampling in 2019. High bacterial diversity was detected in all sampling sites. Significant site effects on bacterial composition with increased Chloroflexota and decreased Flavobacteriaceae were only observed between the highest elevation Johnson Mesa 2 plateau and coastal areas. The overall effect of the depth was reflected by the increased of e.g., Cyanobacteria, Propionibacterium, Staphylococcus in the upper surface and Chloroflexota, Acidobacteriota, Actinomycetota at depths below 30 cm. The huge number of unassigned bacteria indicated a potential source of new bacterial species and their ecological role in this extreme environment. For the first time, we showed that the effect of depth on bacterial composition was more significant than the effect of geological bedrock from these previously unexplored regions.