The world's biodiversity is in peril. The major threats to biodiversity globally are habitat change, overexploitation, climate change, invasive species and pollution. Not only do these stressors impact free-living organisms, but they affect parasitic ones as well. Herein, this perspective examines the potential consequences of these anthropogenic perturbations on helminth populations and communities, with emphasis on significant developments over the past decade. Furthermore, several case studies are examined in more detail for each of these threats to biodiversity. While effects are widespread and diverse, for the most part all these environmental stressors have negative effects on parasite populations and communities. Those parasites with complex life cycles that are trophically transmitted are often more at risk, although larval parasites with a wide host spectrum, and directly transmitted ectoparasites, appear less threatened and may even benefit. However, differential effects on hosts and parasites, on parasite life cycle stages and on host–parasite interactions made specific predictions difficult and context-dependent. Experimental laboratory and mesocosm studies on specific parasites that test effects on the different life cycle stages, hosts and host–parasite interactions, permitting the determination of net effects of an environmental stressor, yield insightful and sometimes counterintuitive results, although they remain a simplification of real-world complexity. Recent advances in the use of parasites as bioindicators of effects also are discussed.

Schistosoma mansoni is the most common species causing schistosomiasis. It has a complex life cycle involving a vertebrate definitive host and a snail intermediate host of the genus Biomphalaria. Each stage encounters a plethora of environmental stresses specially heat stress. Another sort of stress arises from repeated exposure of the parasite to praziquantel (PZQ), the only drug used for treatment, which leads to the development of resistance in the fields and the labs. Heat shock protein 70 (Hsp70) is found in different developmental stages of S. mansoni. It is immunogenic and regulate cercarial invasion besides its chaperone function. In the Biomphalaria/S. mansoni interaction, epigenetic modulations of the Hsp70 gene underscore the susceptibility phenotype of the snail. Hsp70 is up-regulated in adult S. mansoni with decreased sensitivity to PZQ. This could be due to the induction of oxidative and endoplasmic reticulum stress, induction of apoptosis, exposure to the stressful drug pressure and increase influx of calcium ions. Up-regulation of Hsp70 might help the worm to survive the schistosomicidal effect of the drug mainly by dealing with misfolded proteins, inhibition of apoptosis, induction of autophagy, up-regulation of the P-glycoprotein transporter and attenuation of the signalling from G protein coupled receptors.

Oregon’s Willamette Valley is the major cool-season, grass-seed-production area in the world. Roughstalk bluegrass (RB) is a weed in waterlogged, grass-seed-crop fields. Growth chamber and greenhouse studies were conducted to determine the influence of waterlogging on the germination and establishment of RB and tall fescue (TF). Oxygen deficiency resulted in a germination delay in both species, but was greater for TF. Oxygen deficiency at 20 and 30 C was greater for TF compared to RB. Simulated waterlogging for 28 d reduced aboveground biomass more for RB (58%) than for TF (46%), but did not influence seedling survival. Compared to TF, the influence of waterlogging on RB was greater during early establishment. These responses may help RB maintain its germination rate while reducing the damage caused by the accumulation of toxic fermentation-metabolites during waterlogging which benefits RB in competition with TF, especially under high temperatures.

Field experiments were conducted in Alabama during 1999 and 2000 to test the hypothesis that any glyphosate-induced yield suppression in glyphosate-resistant cotton would be less with irrigation than without irrigation. Yield compensation was monitored by observing alterations in plant growth and fruiting patterns. Glyphosate treatments included a nontreated control, 1.12 kg ai/ha applied POST at the 4-leaf stage, 1.12 kg/ha applied DIR at the prebloom stage, and 1.12 kg/ha applied POST at 4-leaf and postemergence directed (DIR) at the prebloom cotton stages. The second variable, irrigation treatment, was established by irrigating plots individually with overhead sprinklers or maintaining them under dryland, nonirrigated conditions. Cotton yield and all measured parameters including lint quality were positively affected by irrigation. Irrigation increased yield 52% compared to nonirrigated cotton. Yield and fiber quality effects were independent of glyphosate treatments. Neither yield nor any of the measured variables that reflected whole plant response were influenced by glyphosate treatment or by a glyphosate by irrigation interaction.

Many substitutions in the herbicide target enzyme acetohydroxyacid synthase (AHAS) confer whole-plant resistance and may reduce plant fitness. This study was done to determine the impact of different watering and temperature regimes on the germination, growth, and seed production of eastern black nightshade populations resistant (R) to AHAS inhibitors as conferred by an Ala205Val substitution in their AHAS. Growth and reproductive ability of four R and four susceptible (S) populations were determined in growth-cabinet and greenhouse studies. The R populations had lower total berry and viable seed production per plant than S under optimal conditions because of slower berry maturation. Seed production of both S and R populations decreased under lower or higher than optimal watering regimes; however, this reduction was more pronounced for the S populations so that seed production was comparable across S and R. The R populations had significantly higher germination and vegetative growth under cooler alternating temperature regimes. Although there were no differences between R and S plants under stress conditions, under optimal growth conditions, the Ala205Val substitution comes at a significant cost in eastern black nightshade. Under optimal growth conditions and in the absence of herbicide selection, S populations should eventually dominate over R; however, the lack of fitness differences under stress conditions could enhance the persistence of the R individuals.

The members of the heat shock protein 70 ( HSP70) family are among the most conserved and widely studied stress proteins. The transcription and translation levels of HSP70 genes have also been studied in several marine and freshwater sponges as molecular markers to characterize the response of sponges to various types of physiological or environmental stress conditions. Furthermore, HSP70 protein sequences have been used in phylogenetic analysis of prokaryotes and eukaryotes. In this study, the expression of HSP70 genes in the marine sponge Thenea muricata during long-term cultivation under laboratory conditions was described at the protein and mRNA levels. Though there are many studies about distribution and morphology of T. muricata, few biochemical and molecular data can be found in the literature. HSP70 gene data for several sponge species have been deposited in the NCBI database, however, those for T. muricata are not available. Therefore, HSP70 genes were characterized in this sponge. Several proteins of the HSP70 superfamily which might be induced by stress, were present in T. muricata.

Ciliates are a primary component of the periphyton microfauna and play a crucial role in the functioning of microbial food webs. Seasonal variation in community structures of periphytic ciliate communities was studied, using glass slides as an artificial substratum, during a 1-year cycle (August 2011–July 2012) in coastal waters of the Yellow Sea, northern China. Samples were collected monthly at a depth of 1 m from four sampling stations. A total of 144 ciliate species representing 78 genera, 43 families, 17 orders and eight classes were recorded. Among these species, 31 distributed in all four seasons, while 11, 11, 13 and two forms occurred only in spring, summer, autumn and winter season, respectively. The species number and total abundance peaked in spring and autumn, with minimum values in winter. Ciliate community structures differed significantly between seasons, and were significantly correlated with the changes in environmental variables, especially temperature, pH, dissolved oxygen (DO) and the nutrients. Of 36 dominant species (top 15 ranked contributors in each season), nine (e.g. Pseudovorticella paracratera, Trochilia minuta and Zoothamnium sp.) were significantly correlated with pH, DO or nutrients. Species richness, evenness and diversity measures were significantly correlated with temperature, pH, DO or soluble reactive phosphates. Results demonstrated that periphytic ciliates exhibited a clear seasonal variation in community structures in response to environmental conditions and potentially might be used as a robust bioindicator for assessing environmental quality status in coastal waters.

The contribution of non-loricate ciliate assemblage to the ecological pattern of a ciliated protozoan community was studied based on a 1-year (June 2007–May 2008) dataset collected from Jiaozhou Bay, northern China. Samples were collected biweekly from five sampling sites. Results showed that: (1) the non-loricate ciliate assemblages were the primary components and significantly correlated with the total ciliate communities in terms of species number, abundance and biomass; (2) the ecological pattern of non-loricate ciliate assemblages was significantly related to that of both total ciliate communities and variations in environmental variables; and (3) spatio-temporal variations in biodiversity (richness, diversity and evenness of species) indices of non-loricate ciliate assemblages were significantly correlated with those of total ciliate communities and the environmental conditions, especially nutrients nitrate nitrogen, nitrite nitrogen and soluble reactive phosphorous. These results suggest that the non-loricate ciliates are a primary contributor to the ecological pattern of total ciliate communities and might be used as a potential bioindicator for bioassessment in marine ecosystems.

This study explores the use of an individual's genetic (IGFS) and environmental factor score (IEFS), constructed using genetic model fitting of a multivariate strength phenotype. Maximal isometric and dynamic strength measures, one maximal repetition load (1RM) and muscle cross-sectional area (MCSA) were measured in 25 monozygotic and 16 dizygotic twin pairs. The use of IGFS and IEFS in predicting the sensitivity to environmental stress was evaluated by the association of the scores with strength training gains after a 10-week high resistance strength training programme. Results show a high contribution of genetic factors to the covariation between maximal strength and muscle cross-sectional area (84–97%) at pre-training evaluation. Individual factor scores explained the largest part of the variation in 1RM and other strength measures at pre-training and post-training evaluation respectively. Genes that are switched on due to training stress (gene–environment interaction) could explain the decrease in explained variation over time. A negative correlation was found between IGFS and strength training gains (−0.24 to −0.51, P < 0.05); individuals with a high IGFS tend to gain less strength than individuals with low IGFS. Individual environmental factor scores have lower differential power. The predictive value of the IGFS has potential utility in identifying an individual's susceptibility to environmental stress in a variety of multifactorial characteristics, eg diseases and impairments, and for selection of sib pairs for QTL analyses. Twin Research (2000) 3, 99–108.

The hypothesis tested in this study is that changes in benthic ecosystem components interrelationships may mirror the degree of environmental stress in the Mediterranean coastal lagoons. Multivariate matrices deriving from four benthic components (macrophytes, zoobenthos, epibenthic decapods and demersal fish) from four lagoonal stations along a well-defined disturbance gradient were compared by means of second-stage non-metric multidimensional scaling (MDS). The resulting inter-matrix distances were used as a proxy for the identification of the degree of disturbance. The approach followed is novel in that it uses information from higher levels of the biological organization by taking into account more than a single benthic component, thus representing broad categories of functional groups. The second-stage MDS plots depict differences between inter-component distances in the sampling stations according to the degree of disturbance they experience and the BIOENV analysis demonstrates that certain components are correlated with the environmental variables at a higher degree in the most disturbed stations.

French oyster farming has been subject to severe mortalities during the summer months.Results from the research program “Morest”, which ran from 2000 to 2006 and examined thepossible causes of these mortalities, led to the construction of a model to explain theinteraction between environmental factors, oyster physiology and different opportunisticpathogens underlying oyster summer mortality. Temperature, food, reproduction and stresswere the main factors required for oyster mortality. Genetically-based resistance (“R”oysters) or susceptibility (“S” oysters) to summer mortality was revealed by divergentselection. Building on these results, a literature search was made in 2007 on themolecular origin of genetic resistance to such a complex mortality risk. The objectiveswere to lay a foundation for the preparation and orientation of future research directionsand to improve understanding of the underlying physiological mechanism leading to summermortality. Three years later, the resulting conceptual analysis reported here waspresented as an introductory lecture to Physiomar 2010, a conference where many newresults contributing to this research field were also reported. The literature reviewhighlighted two major review articles: the first dealing with nutrition and reproduction(Schneider 2004), the second with reproduction,temperature, oxidative stress and mortality (Heineinger 2002). The effect of nutrition level on energy orientation to growth orreproduction is controlled by endocrine factors. Among these, neuropeptide Y (NPY),ghrelin and leptin neuropeptides appeared to be potential candidates involved in germ-somaorientation in relation to trophic conditions. Depending on reproductive effort andtemperature, a metabolic stress resulting from the germ-soma conflict can appear,characterized by mitochondrial reactive oxygen species (ROS) production. Such an excess ofROS induces perturbations in mitochondrial activity leading to cell death. Many organisms,such as annual plants or the Pacific salmon, do not survive their first reproduction. Incontrast, others increase stress resistance by selection of antioxidant processes(superoxide dismutase SOD, catalase, etc.) through evolution, and survive firstreproduction. A similar difference was observed in the comparison made between R and Soysters, which differed in ROS production, SOD and catalase levels. Such factorscontrolling reproduction and ROS detoxification processes could therefore provide newmarkers for selection of oysters with better resistance to non-specific pathogens,complementing other classic selection approaches against specific pathogens or forimproved immunity. This antioxidant defence mechanism is found in many organisms includingvertebrates and in some invertebrates, including oysters. Its role needs to be consideredin pathology events involving other aquaculture species and it may also contribute toexplaining the increase in marine pathologies under anthropogenic environmental changes.

Benthic polychaetes in the largest intertidal mudflat of Hong Kong were analysed for potentially stressed environmental conditions from pollution. Over a two-year period, a total of 14 species were recorded with the species diversity (H′(log2)) ranged from 0.54 to 2.4. The community was dominated by two large polychaetes (Neanthes glandicincta and Potamilla acuminata) and a number of small pollution tolerant species (Tharyx, Capitella capitata and Prionospio cirrifera). It was also characterized by both temporal and spatial variations in terms of abundance and species composition with the lowest species number observed at onshore Station B in August and the highest at offshore Station D in February. Two distinct polychaete communities were formed along the intertidal towards subtidal mudflat, particularly the assemblage at onshore Station B showing a significant difference from those at the other three stations (P < 0.05, N = 32). Results of the abundance–biomass comparison (ABC) indicated a typical impacted community at the whole study area, especially at Station B which was close to the Shenzhen River mouth and mangrove forest. The total organic carbon had a significant positive effect on the abundance of Capitella capitata (P = 0.037, N = 8) while sedimentary compositions were statistically related to the abundance of Potamilla acuminata, Tharyx and total abundance of polychaetes (P < 0.05, N = 8). In conclusion, both the polluted Shenzhen River and nearby mangrove may be responsible for the decline in species richness and diversity as well as changes in community structure. Polychaetes can be used as the appropriate indicators in habitat ecological condition assessment instead of the whole benthic community.

The nurse effect is a positive interaction in which one plant (the nurse) provides conditions that enhance the establishment and growth of another plant species (Callaway 1995). Increased environmental severity appeared to increase the strength of nurse effects (Brooker et al. 2008, Lortie & Callaway 2006). On the one hand, the impact of the nurse effect depends on the magnitude of the environmental changes exerted by the nurse plant. On the other hand, the impact could depend on the number of plant species in the regional pool that respond to such changes. For example, better conditions beneath the crowns of nurse plants might allow the occurrence of species that are sensitive to environmental stress and that occur infrequently in open areas. Thus, if a nurse plant modulates environmental conditions that are critical for the persistence of other plant species, it seems likely that such nurse plants would have greater effects in stressful habitats, where they cause relatively larger environmental mitigation (Badano et al. 2006, Callaway et al. 2002).

In order to evaluate the environmental status within a mariculture pond, temporal variations of physico-chemical factors, protist community structure and interactions between biota and environmental conditions were investigated during a complete cycle in semi-enclosed shrimp-farming waters near Qingdao, north China. Results revealed that: (1) a total of 54 protist taxa with ten dominant species was present, comprising 4 chlorophyceans, 2 chrysophyceans, 5 cryptophyceans, 10 dinoflagellates, 3 euglenophyceans, 10 diatoms, 18 ciliates and 2 sarcodines; (2) a single peak of protist abundance occurred in October, mainly due to the chlorophyceans, diatoms and chrysophyceans, while the bimodal peaks of biomass in July and October were mainly due to the ciliates, dinoflagellates and diatoms; (3) the succession of protist communities significantly correlated with the changes of nutrients, salinity and temperature, especially phosphate, either alone or in combination with NO3; (4) species diversity and evenness indices were found to be relatively independent of physico-chemical factors, whereas species richness and the ratio of biomass to abundance were strongly correlated with water temperature and abundances of bacteria. It was concluded that planktonic protists are potentially useful bioindicators of water quality in a semi-enclosed mariculture system.

Genomic and proteomic diversity provide the basis of evolutionary change by natural selection under abiotic and biotic stresses, and the human-driven evolutionary process of domestication by artificial selection. Described here are some of the regional and local genomic and proteomic long-term multidisciplinary studies conducted at the Institute of Evolution, University of Haifa, Israel, during 1975–2005 (see publications at http://evolution.haifa.ac.il), involving both wild barley, Hordeum spontaneum, the progenitor of cultivated barley and wild emmer sheat, Triticum dicoccoides, the progenitor of modern tetraploid and hexaploid cultivated wheat. Wild cereals harbour large amounts of as yet untapped adaptive genetic resources for crop improvement (resistances against abiotic and biotic stresses, micronutrient metal deficiencies, storage proteins, amylases and photosynthetic yield, among others). The adaptive genomic diversity of wild cereals, including cryptic beneficial alleles at specific quantitative trait loci of T. dicoccoides and H. spontaneum is the best genomic resource to be conserved in situ and ex situ for utilization by classical and modern biotechnologies, to enrich the genetically impoverished and stress-vulnerable food cultivars, advance crop improvement, and thereby increase and optimize world food production in a second genetic green revolution.

Immunological alterations may be used as ecotoxicological biomarkers to detect and monitor biological effects of chemical contaminants in polluted environments. This study reports on a survey of Pacific oysters from the Atlantic coast of Britanny (France) after the “Erika” oil spill. Reared stocks were sampled twice a year from November 2001 to March 2003 at three impacted sites and at an additional site outside the spill area. A multiparametric diagnosis of the immune system was performed on individual hemolymph samples to identify structural, immunopathological alterations and functional impairment of immunocompetent cells. One year after the spill, severe immunological alterations were observed in a site heavily impacted by oil. Since the oysters there had higher contents of PAH compared to the other sites, it was suggested that chronic contamination, possibly generated by oil trapped in the sediments, had induced immunotoxicity. Moreover, moderate variations in some hemolymph parameters observed at the non-impacted area strongly suggested that natural environmental factors may have generated physiological stress. An immunotoxicological index applied here in order to integrate all measurements of defense-related functions appeared to be an efficient tool to identify samples suffering immunological stress.

Deschampsia antarctica Desv. is one of two vascular plants from the Maritime Antarctic. It is usually exposed to cold, salt, and desiccating winds. We hypothesize that D. antarctica has genes that encode dehydrin proteins and their expression is regulated by low temperature, salt or osmotic stress. To test this hypothesis a fragment of a dehydrin gene from D. antarctica was identified and used as a probe to study dehydrin expression under low temperature, salt, and osmotic stress, and exogenous ABA (abscisic acid) treatments. An anti-dehydrin antibody was also used to study dehydrin protein accumulation under the same treatments. Southern analysis of genomic DNA treated with different endonucleases showed more than four bands recognized by the probe, suggesting that D. antarctica has several dehydrin genes. Northern analysis showed two putative dehydrin transcripts of 1.0 kb accumulated only under exogenous ABA and 1.6 kb under osmotic and salt treatments, suggesting that D. antarctica would have ABA-dependent and - independent pathways for regulation of dehydrin expression. Western analysis showed seven dehydrin proteins (58, 57, 55, 53, 48, 30 and 27 kDa) under the different stress treatments. Cold-accumulated dehydrin proteins were immunolocalized, showing that they are associated with vascular and epidermal tissue, which are preferential ice nucleation zones.

This paper is based on two articles by the authors that were published in the March and September 2002 issues of the Journal of Japan Institute of Navigation.

The collision risk to multiple targets and identification of feasible evasive manoeuvres can be assessed simultaneously in true motion by judging the tip of own ship's velocity vector in relation to the display of cone-shaped collision danger regions to acquired targets. Simulator test programmes composed of scenarios with various traffic densities and different speed ranges of own ship have been carried out in order to evaluate the performance of this collision avoidance display versus ARPA (true and relative motion) displays. Experienced navigators and maritime university students with license participated as test subjects. It is shown that the proposed display is capable to facilitate more homogeneous, precise and safe evasive manoeuvres than utilising conventional judgement techniques. The superiority increases with the excess speed of own ship, traffic density and complexity.

We examined the roles that seasonal shifts in precipitation and temperature played in the ectomycorrhizal (ECM) colonization of pinyon pine (Pinus edulis Engelm.) at two contrasting sites in northern Arizona. Pinyons growing in ash and cinder soils experienced much greater water and nutrient stress than pinyons growing nearby in sandy-loam soils. Over a one year period, we obtained monthly measurements of ECM colonization, root zone soil moisture and temperature, and air temperature and precipitation. Four major patterns emerged. Firstly, although climate as measured by ambient temperature and precipitation did not vary between the two sites, soil temperature was significantly higher and soil moisture significantly lower at the cinder site than at the sandy-loam site. Secondly, ECM colonization was significantly higher at the cinder site for 5 of 12 months. Thirdly, although nearly 70% of the variation in ECM colonization of pinyons growing in cinder soil was predicted by a combination of soil moisture and soil temperature, these same variables had little predictive power for pinyons growing in sandy-loam soils. Air temperature and precipitation were also significantly correlated with ECM colonization at the cinder site but not the sandy-loam site. Fourthly, a watering experiment showed that ECM colonization significantly increased with supplemental water at the cinder site, but not at the sandy-loam site. Thus, in two sites that did not differ in plant community or climate, ectomycorrhizas in cinder soils were far more sensitive to changes in moisture and temperature than ectomycorrhizas in sandy-loam soils.

Sclerophylly and synthesis of phenolic compounds are active responses of plants subjected to environmental stress (drought, low nutrient supply, u.v.-B radiation, ozone). Here we describe the morphological and histochemical alterations occurring in field-grown leaves of Fagus sylvatica L. from three sites located along an ecological gradient: from a site in cool and protected conditions to one located on a mountain ridge, where the trees grow on a thin layer of soil and are exposed to the wind and to intense solar radiation in summer. The morphological data show that, as the ecological conditions of the stand worsen, individual leaf surface decreases, while the thickness of the leaves and their specific d. wt (i.e. d. wt per unit leaf area) increases. Histochemical and ultrastructural tests show a marked increase of phenolics during the course of the year. These substances, present primarily in the leaves of trees growing in stress conditions, have been identified mainly as tannins. They accumulate in the vacuoles, especially those of the upper epidermal layer and the palisade mesophyll; at a later stage they appear to be solubilized in the cytoplasm and retranslocated, eventually impregnating the outer wall of the epidermal cells amidst the cellulose fibrils, where they cluster together and form an electron-opaque layer between the wall and the cuticle. Observation of the epidermal cells also reveals that the outer cell wall is thicker. The paper discusses the roles of secondary metabolites in protection and detoxification processes; the possible ecological significance of these alterations in the ecophysiology of beech trees.