Distribution of soft-bottom polychaetes in two coastal areas of the Tyrrhenian Sea (Italy): Structural analysis

Multidimensional statistical analysis was used to study the polychaete distribution in soft-bottoms of two coastal areas of the Tyrrhenian Sea (Italy), which are influenced by the discharges of the rivers Tiber and Ombrone. In both areas the distributional patterns of these organisms are determined mainly by sediment types and related factors such as hydrodynamics, river input, and sedimentation. The grain-size gradient from the coast to the open sea affects not only species composition, but also species richness, diversity and abundance.In both areas three main communities have been identified: a sandy biocoenosis, a mixed-sediment biocoenosis and a muddy biocoenosis. The sandy coastal community is characterized by only a few species, while the intermediate zone of sandy-mud sediments presents the highest species richness and diversity. At the mouth of the River Tiber the influence of the river is more evident than at the mouth of the River Ombrone. This is due to the Tiber's greater river flow, which determines an environmental uniformity and a ‘cenotic continuum’ from sandy to muddy communities. This does not occur at the mouth of the Ombrone, where the river flow is less important and the polychaete communities are better defined.     

A STUDY ON THE PLANKTON COMMUNITIES IN THE SOUTH HUANGHAI SEA AND THE EAST CHINA SEA

The South Huanghai Sea and the East China Sea lie on the east continental shelf ofChina. These areas are generally under the effects of river, coastal currents, and coldwater in the Huanghai Sea, as well as the branches of Kuroshio. Therefore, obviously, thephysical oceanography, chemical elements and plankton distribution in these areas areconsiderably complicated. As for plankton composition, there are temperate neriticspecise, brackish water and estuarine species, coastal species and also tropical pelagicspecies. Each community of the plankton occupies a distributional area of its own.Among the communities there exists a transitional area caused by horizontal andvertical mixing of water masses which effect this area in different degrees. All commu-nities and the transitional area are more or less relatively stable, except for seasonal varia-tion.     

Short-term variability of the phytoplankton community in coastal ecosystem in response to physical and chemical conditions' changes

The short-term dynamics (time scale of a few days) of phytoplankton communities in coastal ecosystems, particularly those of toxic species, are often neglected. Such phenomena can be important, especially since these very species can endanger the sustainability of shellfish farming. In this study, we investigated the short-term changes in phytoplankton community structure (species succession) in two coastal zones in parallel with physical and chemical conditions. Mixing events with allochtonous waters could thus be distinguished from local processes associated with population growth when it was associated with a change in light or nutrient limitation. Mixing events and water advection influenced fluctuations in total phytoplankton biomass and concentration of dominant species, while local processes influenced delayed changes in community structure. The estuarine species Asterionellopsis glacialis increased in concentration when the water mass mixed with the nearest estuarine water masses. The biological response, measured as photosynthetic capacity, occurred after a time-lag of a few hours, while the changes in community structure occurred after a time-lag of a few days. Finally, the coastal water mass was constantly mixed with both the nearest estuarine and marine water masses, leading in turn to delayed changes in phytoplankton community structure. These changes in species composition and dominance were observed on a time scale of a few days, which means that some toxic species may be missed with a bi-weekly sampling strategy.     

厦门及其邻区海岸高等植物的分布

本文研究了厦门及其邻区海岸高等植物的种类组成、分布规律和植物群落概貌。鉴定了该区海岸高等植物325种,隶属于228属79科,其中沙生和盐生植物有43种。据海岸基质类型的不同,可分为沙生、盐生、基岩和广生境4个生态类群。有15个主要植物群落,如海边月见菜、红树林、草海桐群落等。     

Long-term changes in fish communities of the Ria Formosa coastal lagoon (southern Portugal) based on two studies made 20 years apart

Fish communities of the Ria Formosa coastal lagoon (south Portugal) were sampled on a monthly basis with a beach seine at 4 sites, during two different time periods: 1980–1986 and 2001–2002. Community indices, species ranking and multivariate analysis were used in order to identify changes in the fish community between the two time periods. A total of 153,511 fish representing 57 taxa were recorded. Although species composition was very similar for both sampling periods, multivariate analysis performed on annual species abundance in number and weight revealed differences in fish community structure between the two periods. Structural changes in fish community were related mostly to a sharp decrease in the abundance of Mugilidae from 1980–1986 to 2001–2002. These changes were probably associated to a decrease in organic matter contents and nutrients concentrations due to improvements in sewage treatment and better water circulation inside the lagoon. The changes in fish community structure are more evident in the inner areas of the lagoon than near the inlet. The association between changes in sewage patterns and changes in the ichthyofaunal community structure reinforces the importance of fish communities as a biological indicator of human induced changes in marine systems.     

Biotic variation in coastal water bodies in Sussex, England: Implications for saline lagoons

Coastal water bodies are a heterogeneous resource typified by high spatial and temporal variability and threatened by anthropogenic impacts. This includes saline lagoons, which support a specialist biota and are a priority habitat for nature conservation. This paper describes the biotic variation in coastal water bodies in Sussex, England, in order to characterise the distinctiveness of the saline lagoon community and elucidate environmental factors that determine its distribution. Twenty-eight coastal water bodies were surveyed for their aquatic flora and invertebrate fauna and a suite of exploratory environmental variables compiled. Ordination and cluster analyses were used to examine patterns in community composition and relate these to environmental parameters. Biotic variation in the coastal water body resource was high. Salinity was the main environmental parameter explaining the regional distribution of taxa; freshwater and saline assemblages were evident and related to sea water ingress. Freshwater sites were indicated by the plant Myriophyllum spicatum and gastropod mollusc Lymnaea peregra, while more saline communities supported marine and brackish water taxa, notably a range of chlorophytic algae and the bivalve mollusc Cerastoderma glaucum. Site community differences were also related to bank slope and parameters describing habitat heterogeneity. A saline lagoon community was discerned within the matrix of biotic variation consisting of specialist lagoonal species with associated typically euryhaline taxa. For fauna, the latter were the molluscs Abra tenuis and Hydrobia ulvae, and the crustaceans Corophium volutator and Palaemonetes varians, and for flora they were the algae Ulva lactuca, Chaetomorpha mediterranea, Cladophora spp. and Enteromorpha intestinalis. One non-native polychaete species, Ficopomatus enigmaticus, also strongly influenced community structure within the lagoonal resource. The community was not well defined as specialist and associated taxa were distributed throughout the spectrum of sites surveyed. Implications for the identification and conservation of saline lagoons are discussed.     

Ecological thresholds of phytoplankton community across environmental gradients in the harmful algal blooms-frequently-occurring,subtropical coastal waters,East China Sea

Phytoplankton communities can response immediately and directly to environmental changes,and thus have been applied as reliable biotic indicators in aquatic systems.This study provided insights into the relationships concerning ecological thresholds of phytoplankton communities and individual taxon in response to environmental changes in coastal waters of northern Zhejiang Province,East China Sea.Results demonstrated that there existed seasonal variations of phytoplankton community ecological thresholds of which spring being higher than those in summer.As for individual species,Prorocentrum donghaiense and Noctiluca scintillans were identified as the most tolerant and sensitive indicator species in spring and summer,respectively.They exhibited strong indications in response to environmental changes.These findings highlighted that phytoplankton community structure in this region was stable when environmental gradients were below the thresholds of sensitive species,whereas potential harmful algal blooms may occur when environmental gradients exceeded the thresholds of tolerant species.     

东海西南近岸海域污损生物群落特征

于2013年12月~2014年11月在东海西南近岸海域进行污损生物周年挂板试验,全年共记录污损生物10门49科69属84种,群落组成以近岸暖水种为主,为典型的亚热带内湾型群落,附着盛期为4–9月,夏季污损生物的附着强度最高。固定生活类型的悬浮物食者是该近岸海域污损生物群落的附着主体,网纹藤壶（Amphibalanus reticulatus）是最主要的优势种和代表种,其它优势种还有长鳃麦杆虫（Caprella equilibra）、中胚花筒螅（Ectopleura crocea）、太平洋侧花海葵（Anthopleura nigrescens）、今岛柄涡虫（Stylochus ijimai）、克氏无襟毛虫（Spirobranchus kraussii）、近江牡蛎（Crassostrea rivularis）、翡翠贻贝（Perna viridis）、廉形叶钩虾（Jassa falcata）、强壮板钩虾（Stenothoe valida）、光辉圆扇蟹（Sphaerozius nitidus）和大室别藻苔虫（Biflustra grandicella）等。污损生物群落个体间因附着空间和食物竞争而存在着相互依存或互相制约的关系,又依照对环境因子的适应性而存在着一定的时空分布规律。温度是决定污损生物地理分布的最主要环境因素,物种的温度属性是不同气候带污损生物群落组成差异的本质体现,污损生物的种类数、附着期和附着量与水温有着密切的关系;另外,盐度、水流、光、水产养殖等自然环境或人为因素也是影响污损生物附着的重要影响因子。     

Differences in spatial and seasonal patterns of macrophyte assemblages between a coastal lagoon and the open sea

Although benthic macrophytes must be considered in monitoring programs to establish the ecological status of transitional and coastal waters in the European Union, the patterns of variability in species composition of macrophyte assemblages in Mediterranean coastal lagoons has scarcely been studied. In this work the spatial (both vertical and horizontal) and seasonal dynamics of macrophyte assemblages in a coastal lagoon (Mar Menor) are compared with those of open coastal assemblages in the SW Mediterranean to analyze any biological variability in lagoon assemblages and the factors that determine such variability. Different assemblages, characterized by well defined groups of species, can be described according to their isolation from the open sea and the type of substratum; at the same time, a vertical zonation pattern, similar to that found in all marine communities but more compressed, exists. This implies that when applying the EU Water Framework Directive or assessing environmental impact, a lagoon should not be considered spatially uniform and unique unit but as a mosaic of assemblages.     

中国亚热带-热带3个海区微型鞭毛虫群落优势种和稀有种的分布特征和建群机制

海洋微型鞭毛虫是海洋微型真核浮游生物中非常重要的一大类群,在构成和维持海洋生态系统的结构和功能中扮演着重要角色。微生物群落通常由少数优势种和大量稀有种组成,这种分布模式在海洋微型鞭毛虫群落中也极为常见,并且二者的内在特征可能对群落生物地理分布格局以及生态系统功能产生不同影响。然而在多数研究中并未将两种不同亚群落进行区分,对二者的分布特征、对环境和空间因子的响应以及在总体群落中的生态地位等的认识十分有限。本研究利用高通量测序技术,调查了中国近海亚热带 热带3个自然海区微型鞭毛虫群落中优势种和稀有种的分布特征,并探讨了环境因子和空间因子与不同亚群落之间的关系,利用中性模型揭示了中性过程在群落构建中的作用,最后通过共现网络分析解析了两种不同亚群落在总体群落中的生态地位。结果表明：3个海区微型鞭毛虫群落中的优势类群和稀有类群在多样性和物种组成上具有不同的特征,表现出一定的生物地理分布格局;这与它们受到不同程度环境因子和空间因子的驱动作用有关;中性模型的结果体现了随机过程在两种亚群落中的重要作用;最后,共现网络关系反映出不同丰富程度的生态类群具有重叠但又相异的生态位,从而在同一环境中形成物种的共存,维持了群落结构的稳定,而稀有类群以较高的连接度和更高比例的关键种数目,在网络关系中起到重要的连接作用。本研究初步揭示了中国近海微型鞭毛虫优势种和稀有种的分布特征和建群机制,为深入认识海洋微型鞭毛虫的群落结构、分布格局以及影响其群落构建的生态过程提供理论依据。     

虾池浮游植物群落特征及其与虾病的关系

１９９１年６月至９月对大连地区３个虾场养殖的中国对虾及虾池浮游植物群落进行了调查，研究了虾池浮植物群落的组成结构、数量分布、演替特征及其与虾病之间的关系。结果表明，虾池浮游植物群落组成和数量分布具有较大的突发性；优势种单一，多为赤潮生物种类，有些种类原本为底栖生物；群落演替时间短，变化快；养殖对虾发病症状为红腿和黄鳃，严重出现死亡。浮游植物的总量尤其是赤潮种类的总量与对虾的发病程度有正相关性；群     

Structure of Mesozooplankton Communities in the Coastal Waters of Morocco

Mero- and holoplanktonic organisms from 23 large taxa have been detected in the coastal waters of Morocco. Seven Cladocera species and 164 Copepoda species were identified. Copepod fauna mostly consisted of oceanic epipelagic widely tropical species, but the constant species group (frequency of occurrence over 50%) included neritic and neritic–oceanic widely tropical species. The neritic community that formed a biotopic association with coastal upwelling waters and the distant-neritic community associated with Canary Current waters were the two major communities detected. The former community was characterized by a high abundance and biomass (5700 ind./m³ and 260 mg/m³) and predominance of neritic species. The trophic structure was dominated by thin filter feeders, mixed-food consumers, and small grabbers; the species structure was dominated by Paracalanus indicus, Acartia clausi, and Oncaea curta; the indices of species diversity (3.07 bit/ind.) and evenness (0.63) were relatively low. The latter community was characterized by low abundance and biomass (1150 ind./m³ and 90 mg/m³); variable biotopic, trophic, and species structure; and higher Shannon indices (3.99 bit/ind.) and Pielou (0.75). Seasonal variation of the abundance of organisms was not detected in the communities. Anomalous mesozooplankton states were observed in summer 1998 and winter 1998–1999.     

胶州湾海岸湿地保护:社区参与原则、方法与程序

在对胶州湾海岸湿地进行分类、湿地退化现状研究基础上,认为相关政府部门应该采取建设海岸湿地自然保护区、海岸湿地公园,发展循环经济和严格管理海岸带和海域利用等胶州湾海岸湿地保护与合理利用措施。同时,社区参与也是推动胶州湾海岸湿地保护与合理利用的重要方面。提出了成立社区参与组织,调查社区对湿地资源利用的需求,推广合理利用湿地资源的社区参与项目,协调地方关系、扩大社区参与的范围和领域,开展湿地保护和合理利用的宣传教育等社区参与胶州湾海岸湿地保护的初步措施。     

Limiting similarity, niche filtering and functional diversity in coastal lagoon fish communities

The fundamental idea behind the study of biodiversity patterns is the presumed connection between the shape of species assemblages and the functional ways in which they are organized, this functional organization referring to how species are related to one another, as competitors or members of a web of interactions and to how species are facing similar environmental constraints. Amongst the different facets of biodiversity, functional diversity is certainly a key for ecosystem processes in coastal areas. However, surprisingly, patterns of functional diversity have received little attention until now. After presenting a common framework linking functional diversity patterns to species coexistence theories, the aim of our study was twofold: (1) to seek assembly rules in brackish lagoon fish communities drove by functional traits. To this aim we used null models to examine the influence of two opposing forces acting on community structure: interspecific competition that might prevent the coexistence of the most similar species, and environmental filters that might result in the most similar species to coexist. (2) To seek relationships between fish functional diversity and environmental gradients, if any. Fish sampling was carried out in two coastal lagoons where stations differ considerably in terms of physicochemical parameters. Using morphological functional traits, functional diversity of fish communities was estimated using two recently published indices as well as a new proposed index. Firstly our study was not able to demonstrate a limitation of similarity in coexisting lagoon fishes due to interspecific competition. Conversely our results support the niche filtering hypothesis preventing species too dissimilar from one another to co-occur at the same station. Secondly, salinity was positively related to the functional diversity of fishes in both lagoons suggesting that within species assemblages near the channel species are less redundant than at stations far from the channel where species tend to be functionally similar (benthic and eating zooplankton).     

南长山岛岩岸潮间带底栖藻类群落结构的季节变化格局

南长山岛岩岸潮间带底栖藻类群落的种类组成存在显著的季节差异,4个季节的群落共有种为8种:孔石莼、海黍子、石花菜、江蓠、叉枝藻、小石花菜、叉枝伊谷草和瘤枝凹顶藻。4个季节群落中生物量的变化为:秋季>夏季>冬季>春季。绿藻和褐藻类群主要为暖温性种类,而红藻类群比较复杂,既有暖温带、温带和亚热带性种类,也有寒温带的冷水性种类。4个季节群落的物种优势度序列存在明显的差异,海黍子在春季、夏季和冬季3个群落为第一优势种,瘤枝凹顶藻在秋季为第一优势种。不同季节群落多样性指数变化如下:物种丰富度指数,春季>秋季>冬季>夏季;物种多样性指数,冬季=秋季>春季>夏季;均匀度指数,冬季=秋季>春季>夏季。群落的多样性由红藻类群控制。     

Sand-mediated divergence between shallow reef communities on horizontal and vertical substrata in the western Indian Ocean

Distinctions are rarely made between vertical and horizontal surfaces when assessing reef community composition, yet physical differences are expected because of hydrodynamic differences and sediment accumulation on flat surfaces. As sand often diminishes biotic cover, we hypothesised that vertical surfaces will support a greater biomass but have lower diversity due to domination by a few species. To test this, we quantified sessile communities on vertical and horizontal surfaces at three sites in the Delagoa Bioregion on the east coast of South Africa. Community composition consistently differed: vertical communities were dominated by various filter feeders, especially the ascidian Pyura stolonifera, whereas those on horizontal reef comprised a mixture of filter feeders and various algae. The total number of species and all diversity metrics were significantly greater for horizontal reef surfaces. Contrastingly, Simpson’s dominance and biomass were significantly greater for vertical reef surfaces. Percentage cover of sand explained much of the variation in community composition whereas depth did not. Small-scale topographic differences in substratum orientation associated with differences in sand inundation will therefore influence both α and β diversity. Coastal developments and activities that alter sand movements and delivery to the coastal zone are therefore likely to have a profound influence on the maintenance and diversity of shallow subtidal communities.     

Socio-economic drivers and indicators for artisanal coastal fisheries in Pacific island countries and territories and their use for fisheries management strategies

This is the first regional study of artisanal fisheries in Pacific Island countries and territories that demonstrated that the future of the region's artisanal fishery sector and the livelihood of coastal communities will be highly dependent on alternative subsistence and income sources, which are necessary to reduce fishing pressure to a sustainable level to maintain ecosystem services and food security. The overall objective of this study was to identify socio-economic indicators and drivers to improve the understanding of the dynamics between socio-economic conditions and current exploitation levels of finfish and invertebrates of coastal communities in 17 Pacific Island countries and territories. We showed that exploitation rates and thus possible overexploitation are not solely the consequence of a simple demographic growth process but are in fact a result of the choices people have. Our results confirmed a close relationship between resource exploitation rates and economic development at the national level and the availability of alternative income opportunities at the community level. Multivariate analysis results suggest that communities in countries with somewhat unfavourable conditions and limited access to alternatives and fishing households in communities with overall favourable economic conditions are at highest vulnerability as they have the highest dependence on coastal fisheries resources. Alternative economic opportunities at the national scale and availability of alternative income at the community level vary significantly between cultural groups. Based on our results, the development of management strategies with realistic expectations of ensuring livelihood of coastal communities and sustainable resource use in Pacific Island countries and territories requires a hierarchical and integral approach. Major drivers identified at the regional, cultural and local levels should be used to identify priorities, to assess overall advantages and limitations at the different levels as well as the vulnerability of communities targeted, and to develop strategies accordingly.     

Public perception of development issues: Public awareness can contribute to sustainable development of a small island

Many development projects are undertaken in communities where the local inhabitants have little or no input to the planning and implementation of such projects. Encouraging the active participation of local communities in development projects, through capacity-building and environmental education, has become a major objective of sound development programmes. We have successfully included the local community of Holbox Island, Quintana Roo State, Mexico in our programme for long-term monitoring of coastal pollution in and around their Island. Here we report the progress made by different sectors of the Holbox community over a four-year period during which they have become increasingly responsible for the scientific and technical aspects of assessing water quality. A face-to-face, structured survey was used to evaluate attitudes and perceptions with regard to coastal water pollution and other development issues that concern the Holbox Island community. People in Holbox identified coastal pollution, coastal erosion and garbage dumping as major environmental concerns and have acquired a good level of awareness about the causes and consequences of these issues. Our results also indicate that the public has an improved understanding of the interrelationship between their own behaviour, and that of others, and these environmental issues. Our contribution in the Holbox Island has made a positive step towards providing the local community with essential knowledge regarding environmental, development and social issues, thereby enabling them to become actively involved in the environmental conservation of their island. Continuing efforts in capacity-building and environmental education aim to provide the local community with the knowledge and skills that are necessary for making appropriate choices for the preservation and development of Holbox and the surrounding ecosystems. In the long term, the local community will not only be able to contribute directly to on-going development projects, but will also be in a better position to participate with government agencies in the decision-making process.     

Structural and functional shifts in zoobenthos induced by organic enrichment — Implications for community recovery potential

Habitat change induced by organic enrichment is a growing concern for the sustainability of benthic communities in coastal aquatic environments. This case study describes the spatial and temporal response patterns and the recovery potential of low-diversity benthic communities to organic enrichment at two fish farm locations, during the rearing periods (15 and 20 years, respectively) and the following recovery periods (2 years). The spatial extent of disturbance differed depending on the hydromorphological characteristics of the rearing sites, but degraded macrobenthic communities close to both fish farms were recorded soon after the activity started. Continued organic enrichment resulted in high species turnover-rates and in an altered benthic community composition at both locations. After fish farm abatement, a partial recovery was detected in species richness, but abundance and biomass values were reduced and changes in structural composition remained. Alterations in benthic biological traits were observed at both fish farm locations, implying that organic enrichment might cause changes in benthic community function within low-diversity benthic communities.     

Resilience: What is it and what does it mean for marine policymakers?

Marine policymakers are facing increasing calls to consider the resilience of communities that rely on coastal and marine ecosystem goods and services, and the resilience of natural systems themselves. These calls are in response to increasing threats to coastal communities from external factors such as coastal hazards, possibly associated with climate change, reductions in natural capital often caused by over-fishing and invasive species, and drivers that act to change local and regional economic conditions leading to changes in employment and inequality. However, most communities have had little experience in explicitly managing for resilience. Similarly, our understanding of the factors that make a natural or social system resilient is also somewhat limited. Furthermore, there is a lack of consensus-based definitions and performance measures for assessing resilience. These factors, along with other barriers, will need to be overcome before effective resilience-based management can be implemented.