Biodiversity of air-borne microorganisms at Halley station, Antarctica

A study of air-borne microbial biodiversity over an isolated scientific research station on an ice-shelf in continental Antarctica was undertaken to establish the potential source of microbial colonists. The study aimed to assess: (1) whether microorganisms were likely to have a local (research station) or distant (marine or terrestrial) origin, (2) the effect of changes in sea ice extent on microbial biodiversity and (3) the potential human impact on the environment. Air samples were taken above Halley Research Station during the austral summer and austral winter over a 2-week period. Overall, a low microbial biodiversity was detected, which included many sequence replicates. No significant patterns were detected in the aerial biodiversity between the austral summer and the austral winter. In common with other environmental studies, particularly in the polar regions, many of the sequences obtained were from as yet uncultivated organisms. Very few marine sequences were detected irrespective of the distance to open water, and around one-third of sequences detected were similar to those identified in human studies, though both of these might reflect prevailing wind conditions. The detected aerial microorganisms were markedly different from those obtained in earlier studies over the Antarctic Peninsula in the maritime Antarctic.     

Sources,impacts and trends of pharmaceuticals in the marine and coastal environment

There has been a significant investment in research to define exposures and potential hazards of pharmaceuticals in freshwater and terrestrial ecosystems. A substantial number of integrated environmental risk assessments have been developed in Europe, North America and many other regions for these situations. In contrast, comparatively few empirical studies have been conducted for human and veterinary pharmaceuticals that are likely to enter coastal and marine ecosystems. This is a critical knowledge gap given the significant increase in coastal human populations around the globe and the growth of coastal megacities, together with the increasing importance of coastal aquaculture around the world. There is increasing evidence that pharmaceuticals are present and are impacting on marine and coastal environments. This paper reviews the sources, impacts and concentrations of pharmaceuticals in marine and coastal environments to identify knowledge gaps and suggests focused case studies as a priority for future research.     

Phylogeography of Padina boryana (Dictyotales,Phaeophyceae) around the Thai-Malay Peninsula

The Indo-Pacific Ocean is a biodiversity hotspot for marine organisms. In this area, most of the research has focused on marine animals, such as reef fish, molluscs and other associated coral fauna, but very little has been done on macroalgae. The Thai-Malay Peninsula is an important north–south barrier in this area, which faces two different oceans – the Indian Ocean and the Pacific Ocean. This study aims to investigate genetic distribution patterns of Padina boryana Thivy around the Thai-Malay Peninsula, where it is common. Three DNA marker regions, the mitochondrion-encoded cytochrome c oxidase subunit 3 gene (cox3); the plastid rbcL, and the nuclear internal transcribed spacer 2 (ITS2) were used to evaluate genetic diversity and the relationships within and between populations. Samples were collected from both the Andaman Sea and Gulf of Thailand sides of the peninsula. Parsimony networks and maximum likelihood and Bayesian analyses showed clearly that there are two separated P. boryana lineages, one restricted to the Gulf of Thailand and the other to the Andaman Sea and other areas of the Indo-Pacific. The effect of different ocean currents along the Andaman Sea and Gulf of Thailand may have shaped these populations of P. boryana. This phylogeographic separation, based on persistent currents in the area, may affect other marine organisms along the Thai peninsula.     

Selected contribution: a three-dimensional model for assessment of in vitro toxicity in balaena mysticetus renal tissue.

This study established two- and three-dimensional renal proximal tubular cell cultures of the endangered species bowhead whale (Balaena mysticetus), developed SV40-transfected cultures, and cloned the 61-amino acid open reading frame for the metallothionein protein, the primary binding site for heavy metal contamination in mammals. Microgravity research, modulations in mechanical culture conditions (modeled microgravity), and shear stress have spawned innovative approaches to understanding the dynamics of cellular interactions, gene expression, and differentiation in several cellular systems. These investigations have led to the creation of ex vivo tissue models capable of serving as physiological research analogs for three-dimensional cellular interactions. These models are enabling studies in immune function, tissue modeling for basic research, and neoplasia. Three-dimensional cellular models emulate aspects of in vivo cellular architecture and physiology and may facilitate environmental toxicological studies aimed at elucidating biological functions and responses at the cellular level. Marine mammals occupy a significant ecological niche (72% of the Earth's surface is water) in terms of the potential for information on bioaccumulation and transport of terrestrial and marine environmental toxins in high-order vertebrates. Few ex vivo models of marine mammal physiology exist in vitro to accomplish the aforementioned studies. Techniques developed in this investigation, based on previous tissue modeling successes, may serve to facilitate similar research in other marine mammals.     

HSP70 heat shock proteins and environmental stress in Antarctic marine organisms: A mini-review

The ability to understand and predict the effects of environmental stress on biodiversity is becoming increasingly important in our changing environment. Antarctic marine species are some of the most stenothermal on the planet and many inhabit the waters off the Antarctic Peninsula which is one of the areas where there is rapid regional climate change. Therefore these animals are highly vulnerable to changing environmental temperatures and clearly we need to understand the complexities of their response, not just at the individual species level, but also the implications for the ecosystem as a whole. Heat shock proteins have a long history of use in studies of organism stress responses and have frequently been proposed as potential universal molecular biomarkers, especially for non-model species. In this mini-review, the heat shock response and heat shock proteins (specifically the HSP70 family) are examined in Antarctic marine species alongside their physiological capabilities and limits to answer a series of questions: do these animals have a heat shock response which includes the expression of HSP70 genes? What is the relationship between their heat shock response and physiological capabilities? Can HSP70 genes be used as molecular biomarkers for these species?     

Minimum population size estimates demonstrate an increase in southern elephant seals (Mirounga leonina) on Livingston Island, maritime Antarctica

Southern elephant seals (Mirounga leonina) are apex predators of marine Antarctic food webs, and variations in their populations have been linked to environmental changes. Consequently, measuring and reporting the status of elephant seal populations provide insights into the environmental status of Antarctica. Here, we present new information on the size of the elephant seal subpopulation on Byers Peninsula (Livingston Island, South Shetland Islands, maritime Antarctica). Based on a total count of 1,510 pups, we estimated a total subpopulation size of 5,530 individuals by using a conversion factor of 3.5. This represents an increase of 150 % since the subpopulation was first counted 30 years ago. Based on this finding, we hypothesize that the overall South Georgia stock, to which the subpopulation we estimated on Byers Peninsula belongs, could be increasing instead of remaining stable as previously thought.     

原绿球藻对环境胁迫的生理和分子响应机制

原绿球藻(Prochlorococcus)作为海洋丰度最高的浮游植物,对海洋生态系统的物质循环和能量流动起着重要的驱动作用。原绿球藻生长和光合作用活性容易受到环境胁迫的影响,进而影响整个海洋生态系统的稳定性。因此,研究原绿球藻应对环境胁迫的响应机制具有重要的生态意义。原绿球藻主要通过分化出不同的生态型来适应不同光照和营养盐的海洋环境,但仍然会很难快速适应各种突如其来的海洋环境变化。本文从原绿球藻应对环境胁迫的角度,探讨了其生理和分子响应机制的最新研究进展,包括光系统I循环电子传递在光照变化时发挥的重要作用,通过RNA快速响应而调控基因表达应对环境胁迫,以及在辅助异养细菌的保护下应对活性氧的胁迫等。本文也展望了原绿球藻对环境胁迫响应的生理和分子机制的未来研究方向,旨在为原绿球藻抗逆机制的深入研究提供参考。     

Influence of seasonal environmental variables on the distribution of presumptive fecal Coliforms around an Antarctic research station

Factors affecting fecal microorganism survival and distribution in the Antarctic marine environment include solar radiation, water salinity, temperature, sea ice conditions, and fecal input by humans and local wildlife populations. This study assessed the influence of these factors on the distribution of presumptive fecal coliforms around Rothera Point, Adelaide Island, Antarctic Peninsula during the austral summer and winter of February 1999 to September 1999. Each factor had a different degree of influence depending on the time of year. In summer (February), although the station population was high, presumptive fecal coliform concentrations were low, probably due to the biologically damaging effects of solar radiation. However, summer algal blooms reduced penetration of solar radiation into the water column. By early winter (April), fecal coliform concentrations were high, due to increased fecal input by migrant wildlife, while solar radiation doses were low. By late winter (September), fecal coliform concentrations were high near the station sewage outfall, as sea ice formation limited solar radiation penetration into the sea and prevented wind-driven water circulation near the outfall. During this study, environmental factors masked the effect of station population numbers on sewage plume size. If sewage production increases throughout the Antarctic, environmental factors may become less significant and effective sewage waste management will become increasingly important. These findings highlight the need for year-round monitoring of fecal coliform distribution in Antarctic waters near research stations to produce realistic evaluations of sewage pollution persistence and dispersal.     

海洋固氮微生物与环境因子关系综述

海洋微生物的固氮作用是海洋氮素循环中一个关键的环节,对海洋生态系统的氮素供给和初级生产力的提高有着重要的意义。本文从海洋生物固氮的研究历史着手,详述了海洋固氮微生物的多样性及固氮活性研究方法,同时从环境因子的角度,总结了CO2浓度、季节变化、营养盐浓度、污染物及生物物种等环境因子对固氮微生物固氮活性的影响,并对海洋固氮微生物的研究前景进行了展望。     

海洋外来物种入侵生态学研究

海洋外来物种入侵已成为最为严重的全球性环境问题之一。海洋生态系统类型多样、环境复杂,其生物入侵的监测、控制与管理难度相对较大。我国对陆地外来生物的入侵已开展了较为深入的研究,但对于海洋外来生物的入侵研究仍处于起步阶段,对其入侵监测、入侵机制、入侵危害的程度以及防治等问题缺乏基础数据。本文在分析国内外海洋外来生物入侵现状的基础上,概述其入侵生态学研究形势及相关成果,包括海洋外来物种的入侵途径、入侵过程、入侵生态效应以及全球变化对入侵的影响等。海洋外来生物的入侵可能对海洋生态系统造成直接或间接的影响,如种间竞争破坏生态环境、与土著种杂交造成遗传污染、病原生物及有毒藻类导致海洋生态灾害加剧等。此外,从政策和法规、入侵风险评估、监测和公共宣传教育、生物信息系统和有效管理机制等方面提出对我国海洋外来物种入侵的防治策略。本研究为我国海洋外来物种的进一步研究提供了参考。     

Influence of Seasonal Environmental Variables on the Distribution of Presumptive Fecal Coliforms around an Antarctic Research Station

Factors affecting fecal microorganism survival and distribution in the Antarctic marine environment include solar radiation, water salinity, temperature, sea ice conditions, and fecal input by humans and local wildlife populations. This study assessed the influence of these factors on the distribution of presumptive fecal coliforms around Rothera Point, Adelaide Island, Antarctic Peninsula during the austral summer and winter of February 1999 to September 1999. Each factor had a different degree of influence depending on the time of year. In summer (February), although the station population was high, presumptive fecal coliform concentrations were low, probably due to the biologically damaging effects of solar radiation. However, summer algal blooms reduced penetration of solar radiation into the water column. By early winter (April), fecal coliform concentrations were high, due to increased fecal input by migrant wildlife, while solar radiation doses were low. By late winter (September), fecal coliform concentrations were high near the station sewage outfall, as sea ice formation limited solar radiation penetration into the sea and prevented wind-driven water circulation near the outfall. During this study, environmental factors masked the effect of station population numbers on sewage plume size. If sewage production increases throughout the Antarctic, environmental factors may become less significant and effective sewage waste management will become increasingly important. These findings highlight the need for year-round monitoring of fecal coliform distribution in Antarctic waters near research stations to produce realistic evaluations of sewage pollution persistence and dispersal.     

Spatially Extensive Standardized Surveys Reveal Widespread,Multi-Decadal Increase in East Antarctic Adélie Penguin Populations

Seabirds are considered to be useful and practical indicators of the state of marine ecosystems because they integrate across changes in the lower trophic levels and the physical environment. Signals from this key group of species can indicate broad scale impacts or response to environmental change. Recent studies of penguin populations, the most commonly abundant Antarctic seabirds in the west Antarctic Peninsula and western Ross Sea, have demonstrated that physical changes in Antarctic marine environments have profound effects on biota at high trophic levels. Large populations of the circumpolar-breeding Adélie penguin occur in East Antarctica, but direct, standardized population data across much of this vast coastline have been more limited than in other Antarctic regions. We combine extensive new population survey data, new population estimation methods, and re-interpreted historical survey data to assess decadal-scale change in East Antarctic Adélie penguin breeding populations. We show that, in contrast to the west Antarctic Peninsula and western Ross Sea where breeding populations have decreased or shown variable trends over the last 30 years, East Antarctic regional populations have almost doubled in abundance since the 1980’s and have been increasing since the earliest counts in the 1960’s. The population changes are associated with five-year lagged changes in the physical environment, suggesting that the changing environment impacts primarily on the pre-breeding age classes. East Antarctic marine ecosystems have been subject to a number of changes over the last 50 years which may have influenced Adélie penguin population growth, including decadal-scale climate variation, an inferred mid-20th century sea-ice contraction, and early-to-mid 20^th century exploitation of fish and whale populations.     

Extracellular enzymes in terrestrial, freshwater, and marine environments: perspectives on system variability and common research needs

Extracellular enzymes produced by heterotrophic microbial communities are major drivers of carbon and nutrient cycling in terrestrial, freshwater, and marine environments. Although carbon and nutrient cycles are coupled on global scales, studies of extracellular enzymes associated with terrestrial, freshwater, and marine microbial communities are not often compared across ecosystems. In part, this disconnect arises because the environmental parameters that control enzyme activities in terrestrial and freshwater systems, such as temperature, pH, and moisture content, have little explanatory power for patterns of enzyme activities in marine systems. Instead, factors such as the functional diversity of microbial communities may explain varying patterns of enzyme activities observed in the ocean to date. In any case, many studies across systems focus on similar issues that highlight the commonalities of microbial community organization. Examples include the effective lifetime of enzymes released into the environment; the extent to which microbial communities coordinate enzyme expression to decompose complex organic substrates; and the influence of microbial community composition on enzyme activities and kinetics. Here we review the often-disparate research foci in terrestrial, freshwater, and marine environments. We consider the extent to which environmental factors may regulate extracellular enzyme activities within each ecosystem, and highlight commonalities and current methodological challenges to identify research questions that may aid in integrating cross-system perspectives in the future.     

海洋微塑料污染的生态效应研究进展

海洋微塑料污染已成为全球性环境问题。微塑料粒径小,易与海洋生物发生相互作用,可通过多种途径进入海洋生物体内,并在其组织和器官中蓄积和转移,对机体产生毒害。微塑料可沿食物链进行传递,威胁海洋生态系统的健康与稳定。因此,海洋生物与微塑料的相互作用以及海洋微塑料污染的生态效应成为当前研究的热点。综述微塑料的生物附着、生物摄入、对海洋生物的毒性效应及其与化学污染物的复合毒性效应研究的基础上,提出未来微塑料生态效应研究应重点关注我国海洋环境中微塑料的污染现状及生物摄入状况、微塑料的生物效应及其毒理学机制研究、微塑料与其他污染物的复合效应、以及微塑料在海洋生态系统中的作用及其生物地球化学行为等。     

Marine reserves along the Sinai Peninsula (northern Red Sea)

The coral world of the northern Red Sea, situated along the shallow waters of the Sinai Peninsula, has been intensively investigated by Israeli scientists during the last decade. Many aspects of these investigations revealed the presence of unique ecosystems which developed mainly after the last postglacial period less than 10,000 years ago! At this time the cooling of the ambient waters swept out most of the neopleistocenic coral formations, and all the richness and diversity of species observed today evolved after those profound events. At present, typical ecoformations, in which the corals comprise the main part, are found in the northern part of the Gulf of Aqaba, around the southern tip (Tiran Straits) of the Sinai Peninsula, and in the shallow parts of the Gulf of Suez. In 1967 teams of our scientists investigated the marine habitats, and a number of marine parks and sanctuaries, protected by law, have been established. Thus destruction of unique faunal elements is being prevented. Today, with the withdrawal of Israel and the return of Egypt to its territories, such parks should receive much attention and remain protected habitats for the benefit of nature and mankind.     

Immunological function in marine invertebrates: Responses to environmental perturbation

The inception of ecological immunology has led to an increase in the number of studies investigating the impact of environmental stressors on host immune defence mechanisms. This in turn has led to an increased understanding of the importance of invertebrate groups for immunological research. This review discusses the advances made within marine invertebrate ecological immunology over the past decade. By demonstrating the environmental stressors tested, the immune parameters typically investigated, and the species that have received the greatest level of investigation, this review provides a critical assessment of the field of marine invertebrate ecological immunology. In highlighting the methodologies employed within this field, our current inability to understand the true ecological significance of any immune dysfunction caused by environmental stressors is outlined. Additionally, a number of examples are provided in which studies successfully demonstrate a measure of immunocompetence through alterations in disease resistance and organism survival to a realized pathogenic threat. Consequently, this review highlights the potential to advance our current understanding of the ecological and evolutionary significance of environmental stressor related immune dysfunction. Furthermore, the potential for the advancement of our understanding of the immune system of marine invertebrates, through the incorporation of newly emerging and novel molecular techniques, is emphasized.     

Review of stress in marine mammals

There has been a growing concern over the last few decades about theeffects of environmental stress, including anthropogenic impacts, onmarine mammals. This paper provides an overview of the wide range ofanthropogenic stressors that marine mammals may encounter and the levelof understanding on their potential effects. Sources of stress andphysiological responses of the animals are explored. Many of the lifehistory traits of marine mammals (i.e., long-life spans, late maturity,relatively low reproductive potential, and feeding high in the foodchain), make them susceptible to various anthropogenic stressors. Sincemarine mammals are exposed to a diverse array of multiple stressors,this paper focuses on three case studies (acute and chronic effects fromoil spills; chronic effects from environmental contaminants, andfishery-induced stress) to emphasize potential relevant hazards and toprovide a perspective on the use of marine mammals in assessingecosystem health. Additional research to enhance our understanding ofstress on marine mammals and to provide the science needed to guidemanagement decisions is recommended.     

海洋鱼类肠道微生物研究进展及应用前景

肠道微生物在动物体内数量庞大、结构复杂,在宿主生长发育过程中发挥着重要作用.淡水鱼类肠道微生物的研究主要集中于其对鱼类生长代谢、营养吸收及免疫调节等方面的影响,海洋鱼类则研究相对较少,且多集中于肠道微生物多样性及其变动影响因素分析.本文在归纳总结鱼类肠道微生物功能及其研究方法的基础上,着重分析肠道微生物在海洋鱼类生长发...     

Flow cytometry in oceanography 1989--1999: environmental challenges and research trends.

BACKGROUND: The present review is based on the identification of four major environmental crises that have been approached from a biological oceanographic viewpoint. These crises are the release of contaminants in near shore marine waters, the collapse of marine resources that were renewable until recently, the loss of biodiversity, and global climate change METHODS: The review examines the contribution of cytometry-based biological oceanography to the resolution of the four environmental crises. Using a database of 302 papers, flow cytometric (FCM) studies in biological oceanography over the 1989--1999 decade are examined. Future biological oceanographic applications of FCM are discussed. RESULTS: Most of the published FCM oceanographic studies focus on phytoplankton and bacterioplankton. Analysis of our 1989-1999 database shows the predominance of studies dedicated to phytoplankton (77%), followed by heterotrophic bacteria (21%). The latter progressively increased over the last decade, together with the improved understanding of the biogeochemical and trophic roles of marine bacteria. Most studies on these two microorganisms were conducted in vitro until 1996, after which the trend reversed in favor of in situ research. The most investigated areas were those with major international sampling efforts, related to the changing climate. Concerning environmental topics, 62% of papers on phytoplankton and bacterioplankton focused on the structure of microbial communities and fluxes (e.g., production, grazing); this provides the basis for biological oceanographic studies on resources and climate change. CONCLUSIONS: Future progress in the biological oceanographic use of FCM will likely fall into two categories, i.e., applications where FCM will be combined with the development of other methods and those where FCM will be the main analytical tool. It is expected that FCM and other cytometric approaches will improve the ability of biological oceanography to address the major environmental challenges that are confronting human societies.