Assessment of the likely sensitivity to climate change for the key marine species in the southern Benguela system

Climate change is altering many environmental parameters of coastal waters and open oceans, leading to substantial present-day and projected changes in the distribution, abundance and phenology of marine species. Attempts to assess how each species might respond to climate change can be data-, resource- and time-intensive. Moreover, in many regions of the world, including South Africa, species may be of vital socioeconomic or ecological importance though critical gaps may exist in our basic biological or ecological knowledge of the species. Here, we adapt and apply a trait-based sensitivity assessment for the key marine species in the southern Benguela system to estimate their potential relative sensitivity to the impacts of climate change. For our analysis, 40 priority species were selected based on their socioeconomic, ecological and/or recreational importance in the system. An extensive literature review and consultation with experts was undertaken concerning each species to gather information on their life history, habitat use and potential stressors. Fourteen attributes were used to estimate the selected species’ sensitivity and capacity to respond to climate change. A score ranging from low to high sensitivity was given for each attribute, based on the available information. Similarly, a score was assigned to the type and quality of information used to score each particular attribute, allowing an assessment of data-quality inputs for each species. The analysis identified the white steenbras Lithognathus lithognathus, soupfin shark Galeorhinus galeus, St Joseph Callorhinchus capensis and abalone Haliotis midae as potentially the most sensitive species to climate-change impacts in the southern Benguela system. There were data gaps for larval dispersal and settlement and metamorphosis cues for most of the evaluated species. Our results can be used by resource managers to determine the type of monitoring, intervention and planning that may be required to best respond to climate change, given the limited resources and significant knowledge gaps in many cases.     

海洋生态系统健康评价的底栖生物指数法研究进展

海洋大型底栖无脊椎动物能对自然和人为活动导致的水和沉积物质量变化做出可预测的响应,因此利用底栖生物作为海洋生态环境监测的生物指标和进行系统健康度量的生物指数已经得到了广泛的认可.本文比较分析了几种常用的和正在发展的海洋生态系统健康和生态环境质量状况评估的底栖生物指数,包括指示生物法、Shannon-Wiener多样性指数、BI指数、AMBI指数和Bentix指数,总结了这几种生物指数的应用和特性,探讨了底栖生物指数在实际应用中可能存在的问题和解决的办法,以期为我国海洋生态系统健康评估工作提供参考.     

The role of the stress proteins response in physiological adaptation of marine molluscs

Organisms have evolved a highly conserved cellular response called the heat-shock or stress proteins response (SPR) that increases their tolerance to adverse environmental conditions. We have tested the hypothesis that the tissues of two molluscs, Mytilus edulis and Collisella pelta, respond to stressful situations by eliciting this response. We found that both heat-shock and Cd can induce the SPR in both species and are presently carrying out experiments to correlate the induction of stress proteins with an increased capacity to tolerate subsequent stressful conditions. These experiments should help us determine if the SPR plays an important role in the physiological adaptation of these species to their environment.     

造礁石珊瑚共生藻的分子分类研究

通过nlsrDNA(nuclear large-subunit ribosomal DNA)及nssrDNA(nuclear small-subunit ribosomal DNA)的PCR-RFLP研究广东徐闻地区8科15属25种62个造礁石珊瑚样本的共生藻。结果表明,共生藻nlsrDNA的RsaI酶切基因型只存在一种,属于C系群共生藻;而nssrDNA的MobⅠ和TaqⅠ两种酶切都存在两种基因型。实验进一步通过PCR直接测序法得到62个造礁石珊瑚样品的共生藻ITS序列,与GenBank上的4种虫黄藻ITS序列构建Neighbor-Joining系统发育树,结果表明该区的造礁石珊瑚共生两种不同种类(亚系群)的共生藻,分别为C1亚系群与C15亚系群共生藻,两个亚系群间的遗传距离为0.019。广东徐闻地区造礁石珊瑚共生藻多样性偏低,暗示该地区珊瑚礁生态系统应对环境变化的能力可能较弱。     

Macroecological study of Centropages typicus in the North Atlantic Ocean

Centropages typicus is a temperate neritic-coastal species of the North Atlantic Oceans, generally found between the latitudes of the Mediterranean and the Norwegian Sea. Therefore, the species experiences a large number of environments and adjusts its life cycle in response to changes in key abiotic parameters such as temperature. Using data from the Continuous Plankton Recorder (CPR) survey, we review the macroecology of C. typicus and factors that influence its spatial distribution, phenology and year-to-year to decadal variability. The ecological preferences are identified and quantified. Mechanisms that allow the species to occur in such different environments are discussed and hypotheses are proposed as to how the species adapts to its environment. We show that temperature and both quantity and quality of phytoplankton are important factors explaining the space and time variability of C. typicus. These results show that C. typicus will not respond only to temperature increase in the region but also to changes in phytoplankton abundance, structure and composition and timing of occurrence. Methods such as a decision tree can help to forecast expected changes in the distribution of this species with hydro-climatic forcing.     

Cytochrome P450 in seals: monooxygenase activities, immunochemical cross-reactions and response to phenobarbital treatment

Cytochrome P450 monooxygenase activities, reflecting the expression of various subfamilies of P450, were measured in liver samples of harp and hooded seal. Differences in some of the investigated parameters were observed between the two species, between sexes, and between pups and adults. Treatment of single female pups from each species with phenobarbital (i.v. 45 mg/kg), resulted in increased levels of EROD and estradiol 2-hydroxylase activities in both species, whereas MCOD, ECOD and PROD activities were induced only in the harp seal sample. Antibodies against a dog P450 2B form (anti-dog PBD-2 IgG) gave a single band around 52kD in both species, strongest in male pups. This band seemed elevated in the PB-treated harp seal pup. Based on the single treated pup of each species, the results suggest that seals respond to PB-type treatment with a weaker response, and with different enzyme patterns, that most terrestrial mammals. Antibodies against cod P450 IAI cross-reacted with two bands in liver samples from adult seals of both species (about 54 and 52kD), but this was strongest in the hooded seal. The intensity of the bands reflected the EROD activities in the samples, suggesting the application of immunodetection in screening marine mammals for effects of environmental contamination.     

Changes of macrofaunal functional composition at sedimentary habitats in the vicinity of fish farms

The relationship of functional diversity and composition was studied in gradients of organically enriched sediments from four Mediterranean fish farms. Within-functional trait diversity was also used to examine the functional redundancy of specific functional traits. Characteristics considered to respond to different geochemical conditions of the sediment were chosen for the traits list of that organism and were classified into ecological and morphological traits. Each trait was split up into several categories chosen to encompass the range of possible attributes of all species. The abundance of species possessing the same code was summed for each sample. Functional codes analyses differentiated between the sediment types and the TOC states, confirming the sensitivity of the functional characteristics to the geochemistry of the sediment. Changes in species number and abundance in the compared sites determined the shifts of the functional processes and not the presence or absence of individual traits. The important functional codes for the homogeneity within the examined habitats were fewer in the disturbed areas indicating that the functioning of these ecosystems is significantly reduced.     

中日海洋鱼类与分布的比较研究

论文资料表明中日两国海区共出现４３５１种鱼类，分属３２９科。其中中国分布为３０４８种，日本为３２５４种，两国共有种为１９５１种，占海区鱼类总数的４４．８４％。文中并对上述鱼种依不同海区作了比较分析，其中有上百种鱼种是两国渔业的主要对象。论文指出，中日海洋鱼类的高度多样性是同源扩布的产物；同时，又由于区维与海流系统的差异，导致鱼种在共性基础上的分异。保护海洋鱼类多样性是持续渔业生产的基础，我们应共同努力为建立资源管理型渔业而努力     

Calcidiscus quadriperforatus and Calcidiscus leptoporus as oceanographic tracers in Lisbon Bay (Portugal)

A study of the Calcidiscus genus in Lisbon Bay has revealed the presence of Calcidiscus quadriperforatus and Calcidiscus leptoporus. Samples were collected continuously on a weekly basis for four years (July 2001–May 2005) and on a cruise carried out in summer 2005, covering Lisbon Bay. Calcidiscus quadriperforatus and C. leptoporus developed in the same range of temperature and salinity, 11.5–21.5 °C and 26.9–36.3, respectively. The two species seemed to respond independently but had a co-occurring seasonal pattern nearshore, developing in different concentrations throughout the seasons. The maxima of both species occurred in low turbulent and nutrient enriched waters, which was also favourable for the development of larger coccospheres of C. quadriperforatus. The concentrations of both species decreased from 2001 until 2005, due to the intensification and persistence of upwelling and rainy periods.From late autumn until winter, mixed populations were observed nearshore, largely dominated by Calcidiscus quadriperforatus, in colder and nutrient enriched waters, while during spring, when temperatures begin to increase, only Calcidiscus leptoporus was observed, in mature upwelled waters. Calcidiscus quadriperforatus was considered more opportunistic than C. leptoporus. The availability of nutrients seemed to have influenced the size increase of C. quadriperforatus coccospheres. Both species developed offshore during summer, when the shelf is occupied by colder turbulent upwelled waters. A short downwelling episode in summer 2005, associated with two counter-rotating mesoscale eddies, responsible for a strong north-eastward flow of warm oceanic waters into the bay, allowed the development of C. quadriperforatus nearshore. Contemporary satellite images revealed the presence and onshore displacement of these waters and C. quadriperforatus and C. leptoporus distribution highlighted these conditions. The development of each species nearshore also gave indications of local oceanographic changes during winter and spring.     

Seasonal and interannual variability of the planktic foraminiferal flux in the vicinity of the Azores Current

Planktic foraminiferal (PF) flux and faunal composition from three sediment trap time series of 2002–2004 in the northeastern Atlantic show pronounced year-to-year variations despite similar sea surface temperature (SST). The averaged fauna of the in 2002/2003 is dominated by the species Globigerinita glutinata, whereas in 2003/2004 the averaged fauna is dominated by Globigerinoides ruber. We show that PF species respond primarily to productivity, triggered by the seasonal dynamics of vertical stratification of the upper water column. Multivariate statistical analysis reveals three distinct species groups, linked to bulk particle flux, to chlorophyll concentrations and to summer/fall oligotrophy with high SST and stratification. We speculate that the distinct nutrition strategies of strictly asymbiontic, facultatively symbiontic, and symbiontic species may play a key role in explaining their abundances and temporal succession. Advection of water masses within the Azores Current and species expatriation result in a highly diverse PF assemblage. The Azores Frontal Zone may have influenced the trap site in 2002, indicated by subsurface water cooling, by highest PF flux and high flux of the deep-dwelling species Globorotalia scitula. Similarity analyses with core top samples from the global ocean including 746 sites from the Atlantic suggest that the trap faunas have only poor analogs in the surface sediments. These differences have to be taken into account when estimating past oceanic properties from sediment PF data in the eastern subtropical North Atlantic.     

泉州潮间带贝类的生态分布

报道了泉州市潮间带贝类的种类、数量及其生态分布。经记录整理、鉴定共得标本125种,隶属于3纲、46科和84属。其中,多板纲3种,双壳纲63种,腹足纲59种。根据它们对温度的适应性质可分为4个类群:暖温带种占5.6%;亚热带种占40.8%;广温广布种占48.0%;热带种占5.6%。     

Effects of morphodynamic state on macrofauna community of exposed sandy beaches on Galician coast (NW Spain)

It is known that the fauna of the exposed sandy beaches are primarily controlled by physical variables; but how these variables operate along and across the beach still remains fairly under discussion. In our study, we sampled a range of exposed sandy beaches along the Northwest coast of Spain to determine the relationship between the principal physical variables of the beaches (including beach morphodynamic state), and the macrofaunal community. The fauna of these beaches comprise truly marine species along the intertidal zone as well as semi-terrestrial species in the upper and supratidal environments. These two groups respond in a different manner to the physical environment. The first group is directly controlled by the morphodynamic state of the beach, and variations in the physical environment; the second group is not clearly affected by these physical conditions. In this case, other variables such as food availability and the human uses of the upper limits of the beach seem to be more relevant in explaining the patterns observed in the macrofaunal community.     

Impacts of climate change on commercial fish stocks in Norwegian waters

The Norwegian fishing areas extend over various marine ecosystems that will respond differently to climate change. In the North Sea the productivity of the boreal fish species are likely to decrease under global warming and new warm-water species are expected to become more abundant. In the arctic marine ecosystem of the Barents Sea the fish productivity is expected to increase and their distributions expand northward and eastward under global warming increasing the importance of the Russian as well as the Norwegian sectors of the Barents. In the past, decadal-scale climate variations have been shown to strongly influence productivity and distributions of fish stocks. The importance of such shorter-term variations are expected to continue also under global warming. Under global warming the optimum temperature for fish farming along the Norwegian coast will be displaced northwards from the northern part of West Norway towards the Helgeland coast.     

Brittlestar Color-Change and Phototaxis (Echinodermata: Ophiuroidea: Ophiocomidae).

Abstract. In the first decisive study of color-change in brittlestars, four Caribbean species, Ophiocoma echinata, 0. paucigranulata, O. pumila, and O. wendti are reported to change color from day to night. Color-change is most striking in O. wendti, which is dark brown during the day, and is banded gray and black from dusk to dawn. The transformation occurs over a 3 to 4 hour period and is effected by chromatorphores which appear to respond to illumination, independently of the central nervous system. Color-change may also be mediated by an endogenous rhythm. Ophiocoma wendti is more responsive to light than the other 3 species tested. It reacts to lower levels of illumination at night than during the day, exhibiting negative phototaxis in moonlight as well as in sunlight. I suggest that color-change may expose (or shield) photosensitive tissues that control the brittlestar's detection of shaded fissures in the reef. Thereby, chromatophore activity may be connected with the brittlestar's chief defense from predators, the ability to detect shadow and escape into darkened crevices. Although experiments to date with predacious fish are equivocal. the color patterns of Ophiocoma species mav provide protective camouflage.     

Responses of macrobenthic communities to patchy distributions of heavy metals and petroleum hydrocarbons in sediments:A study in China's Zhoushan Archipelago

This study conducted four cruises during 2014–2017 to investigate relationships between macrobenthic communities and sediment contaminations in sea area around the Zhoushan Archipelago. Fourteen sites were categorized into three groups: high total heavy metal contamination content(HHMC), high total petroleum hydrocarbon content(HTPH), and low content ratio of heavy metal contamination content to total petroleum hydrocarbon content(HMC/TPH) areas. Four main taxa of macrofauna(polychaetes, bivalves, gastropods, and crustaceans) were determined to respond to environmental factors differently. While tolerant polychaetes being the minimal impact by environmental factors, bivalves were threated by heavy metal pollutions in sediment.Additionally, body size distribution frequency demonstrated that macrofauna in the low HMC/TPH areas were less disturbed by contamination than those in the HHMC and HTPH areas. The result represented the presentation of sensitive species while tolerant species are usually considered as small size organisms. Overall,this study confirmed the hypothesis that the contamination levels of small-scale patches is indicated by the condition of macrobenthic communities.     

2019–2020年夏季舟山海域浮游动物优势种生态位及其生态分化

为了解舟山海域浮游动物种间关系及环境因子变化对优势种生态位分化的影响,根据2019年夏季和2020年夏季舟山海域浮游动物调查资料,利用优势度指数判断该海域浮游动物优势种,运用Shannon公式和Pianka公式分析浮游动物优势种生态位宽度和生态位重叠指数,采用冗余分析方法探究影响舟山海域浮游动物优势种生态位分化的主要环境因子。结果表明,舟山海域2019年、2020年浮游动物优势种更替率为66.67%。根据舟山海域浮游动物优势种生态位宽度值,可将其分为广生态位种、中生态位种、窄生态位种,2019年广生态位种有4种,2020年有6种,分别占浮游动物优势种的66.67%和60.00%,表明广生态位种是舟山海域浮游动物优势种的主要组成成分。2019年浮游动物优势种生态位重叠指数范围为0.11～0.79,2020年生态位重叠指数范围为0～0.98。冗余分析表明,2019年浮游动物优势种生态位分化主要受硅酸盐浓度、化学需氧量、温度和叶绿素a浓度的影响,2020年浮游动物优势种生态位分化主要受硅酸盐和溶解氧浓度的影响。该研究有望进一步了解舟山海域浮游动物群落的种间关系,为阐述浮游动物对环境变化的适应...     

The influence of geological, geochemical, and biogenic habitat heterogeneity on seep biodiversity

Cold seeps are among the most heterogeneous of all continental margin habitats. Abiotic sources of heterogeneity in these systems include local variability in fluid flow, geochemistry, and substrate type, which give rise to different sets of microbial communities, microbial symbiont-bearing foundation species, and associated heterotrophic species. Biogenic habitats created by microbial mats and the symbiotic species including vesicomyid clams, bathymodiolin mussels, and siboglinid tubeworms add an additional layer of complexity to seep habitats. These forms of habitat heterogeneity result in a variety of macrofaunal and meiofaunal communities that respond to changes in structural complexity, habitat geochemistry, nutrient sources, and interspecific interactions in different ways and at different scales. These responses are predicted by a set of theoretical metacommunity models, the most appropriate of which for seep systems appears to be the 'species sorting' concept, an extension of niche theory. This concept is demonstrated through predictable patterns of community assembly, succession, and beta-level diversity. These processes are described using a newly developed analytical technique examining the change in the slope of the species accumulation curve with the number of habitats examined. The diversity response to heterogeneity has a consistent form, but quantitatively changes at different seep sites around the world as the types of habitats present and the size-classes of fauna analyzed change. The increase in beta diversity across seep habitat types demonstrates that cold seeps and associated biogenic habitats are significant sources of heterogeneity on continental margins globally.     

Emigrating larvae of koaro,Galaxias brevipinnis Günther (Teleostei: Galaxiidae), from the Otira River,New Zealand

Fish larvae were collected in stream benthic invertebrate drift nets from the Otira River, near Arthur's Pass, New Zealand during a study of benthic drift. They are identified as probably those of koaro (Galaxias brevipinnis Gunther) on the basis of estimates of myomere counts (indicating Galaxiidae or Retropinnidae); by a process of elimination of likely species on the basis of distance up stream, elevation, and habitat characteristics; and by determining fish species in the Otira River tributaries upstream of the sampling location. This comprises the first likely record of emigrating larvae of koaro, a species known to be diadromous by the return migrations from the sea of whitebait juveniles during spring. A newly hatched larva of koaro is described and figured.     

Long-term nutrient variation trends and their potential impact on phytoplankton in the southern Yellow Sea,China

The concentration and composition of nutrients, such as N, P, and Si, respond to biogeochemical processes and in turn, impact the phytoplanktons’ community structure and primary production. In this study, historical data was systematically analyzed to identify long-term variations in nutrient trends, red tide frequency, phytoplankton community abundance, and dominant species succession in the southern Yellow Sea(SYS). Results showed that N/P concentration ratios dramatically increased as a funct...     

Assessing trophic adaptability is critical for understanding the response of predatory fishes to climate change: a case study of Pomatomus saltatrix in a global hotspot

There is a growing need to incorporate biotic interactions, particularly those between predators and their prey, when predicting climate-driven shifts in marine fishes. Predators dependent on a narrow range of prey species should respond rapidly to shifts in the distribution of their prey, whereas those with broad trophic adaptability may respond to shifts in their prey by altering their diet. Small pelagic fishes are an extremely important component of the diet of many marine predators. However, their populations are expected to shift in distribution and fluctuate in abundance as the climate changes. We conducted a comparative study of the seasonal diet of adult Pomatomus saltatrix over two periods (June–December 2006 and 2012) and examined the available data on small pelagic fishes biomass in a global hotspot (the coastal region of southern Angola, southern Africa) to gain an understanding of the tropic adaptability of the species. Despite a drop (630 000 t to 353 000 t) in the abundance of their dominant prey (Sardinella aurita) in the region, it remained the most important prey item during both study periods (Period 1 = 99.3% RI, Period 2 = 85.3% RI, where %RI is a ranking index of relative importance). However, the diet during Period 2 was supplemented with prey typically associated with the nearshore zone. The seasonal data showed that P. saltatrix were capable not only of switching their diet from S. aurita to other prey items, but also of switching their trophic habitat from the pelagic to the nearshore zone. These findings suggest that P. saltatrix will not necessarily co-migrate if there is a climate-driven shift in the distribution of small pelagic fishes (their dominant prey). Accordingly, understanding the trophic adaptability of predators is critical for understanding their response to the impacts of climate change.