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1.
Ecological succession has been scarcely investigated on sublittoral rocky cliffs. The few relevant studies deal with the structure of the developing community and are limited to higher taxa or sessile forms. The objective of the present study was to examine succession patterns on algal‐dominated rocky cliffs both at the structural (species composition) and functional (feeding guild composition) level, using Polychaeta, a dominant taxon in this marine habitat, as a reference group. Cement panels were seasonally installed on the rocky substratum (25–30 m depth) and sampled every 3 months over a 1‐year period. Twenty‐nine polychaete species were recorded, previously reported from the surrounding benthic community, and classified into eight feeding guilds. Most species were assigned as sessile filter‐feeders; this guild dominated in abundance and biomass. A strong effect of the length of immersion and of the seasonal onset of succession on the developed communities was assessed: species composition analyses suggested convergence into a similar organization as succession proceeds, whereas the impact of starting season on succession was stronger when analysing feeding guilds. In both cases succession was faster on panels installed in winter. The main emerging patterns were in agreement with relevant surveys of the entire benthic fauna, thus supporting the efficacy of polychaetes as a surrogate group for studying ecological succession in the benthic marine environment.  相似文献   

2.
A field experiment was carried out in Hong Kong to study the patterns of recolonization and succession of subtidal macrobenthos in defaunated sediment contaminated with petroleum hydrocarbons and to determine the time required for benthic recovery from petroleum contamination. A total of 31 species was found and 83 animals/tray and 14 species/tray on an average were recorded after one month. Initial colonization was dominated by polychaetes in both abundance and species number (accounting for 69.1% and 64.5%, respectively). Abundance of macrobenthos came to a small crest (308 animals/tray) after three months, reached a sharp peak (1257 animals/tray) after six months, and then declined to a steady level. Abundance, species number and diversity in the petroleum-contaminated sediment were significantly lower than those in the control sediment in the early successional stages, indicating deleterious effects of petroleum hydrocarbons on recolonization and succession of macrobenthos. Petroleum hydrocarbons in sediment significantly altered species composition of macrobenthos in recolonization and succession. No significant differences in community parameters and species composition between the petroleum-contaminated and the control communities were found after 11 months, indicating that macrobenthic community had recovered from petroleum contamination.  相似文献   

3.
Understanding species distributions and their community structure is increasingly important when taking an ecosystem‐based approach to conservation and management. However, knowledge of the distribution and community structure of species in mid‐range trophic levels (e.g. macroinvertebrates) is lacking in most marine ecosystems. Our study aimed to examine the spatial distribution and community‐level biogeographic patterns of common kelp forest–rocky reef macroinvertebrates in Southern California and to evaluate the effects of environmental gradients on these communities. Quantitative SCUBA surveys were used to estimate macroinvertebrate densities at 92 sites from 2008–2012. Non‐metric multidimensional scaling was used to evaluate spatial patterns of macroinvertebrate communities among Regions. We found that kelp forest–rocky reef macroinvertebrate communities are distinct among different island and mainland regions, and their community patterns exhibited a strong relationship with an environmental gradient (i.e. sea surface temperature) even after controlling for geographic distance between sites. High abundances of urchin species (Strongylocentrotus purpuratus and Strongylocentrotus franciscanus) were strong drivers of regional differences. Macroinvertebrate community patterns were driven by characteristic species that were typically more prevalent at warmer or colder sites. Our results provide the first quantitative analysis of macroinvertebrate community structure within the California kelp forest ecosystem. We also describe the distribution and abundance of 92 conspicuous kelp forest‐rocky reef macroinvertebrates among nine pre‐defined Regions. This study provides important preliminary information on these macroinvertebrate species that will be directly useful to inform management of invertebrate fisheries and spatial protection of marine resources.  相似文献   

4.
Marine sessile communities developing on stainless steel test panels set 10 and 20 m deep in False Bay over periods ranging from a month to a year were examined. The establishment of communities was characterized by seasonal succession, colonization rates being lowest during winter. Community development differed between depths. At 10 m, barnacles appeared first but numerous mussels settled on them, eventually smothering them. Later, secondary settlement of barnacles on the mussels increased the bulk of the layer. Initial development was slower at the 20 m site, progressing from barnacle dominance to a more complex community including barnacles, serpulids, hydrozoans and compound ascidians. The settlement of solitary ascidians during summer led to their final dominance alongside barnacles. It is suggested that solitary ascidians and barnacles would normally dominate at sublittoral depths up to 20 m in False Bay, except where mussel dominance develops first.  相似文献   

5.
In shallow sublittoral rocky habitats of the Southeast Pacific, two conspicuous ecological systems exist; kelp beds dominated by large Laminariales algae, and barren grounds dominated by crustose coralline algae and sea urchins. The aim of this study was to examine the successional development of micro‐periphyton communities in both ecological systems using a colonization experiment conducted in Northern Chile. In both ecological systems, we installed replicated ceramic plates at 10 m depth and samples were taken after 1, 2, 4, 6, 8 and 14 days of exposure. Bacteria, diatoms, protozoans and small eukaryotes were identified, quantified and analysed. The succession of micro‐periphyton communities in both ecological systems followed a common pattern consisting of a net accumulation of functional groups and taxa over time; however, the total density of all groups was significantly higher in the kelp beds. In addition, the community structure of the developing micro‐periphytons was different and specific for each ecological system. Although previous studies have suggested that kelp beds and barren grounds are capable of switching from one state to the other without substantial changes in biodiversity, our results show that each of these ecological systems promotes its own successional development, suggesting that they are unique, self‐organized entities. This study is the first step towards an understanding of these ecological systems operating independently at this scale of organization.  相似文献   

6.
The effect of test panel submersion season on the colonization of biofouling communities in a tropical coast revealed that the effects of panel submersion time should be taken into consideration for modelling fouling community recruitment dynamics in coastal systems or during the field trials of antifouling coatings. Wooden test panels fitted onto a raft were submerged during pre-monsoon, monsoon and post-monsoon seasons for the development of the biofouling community. Results showed considerable variation in the colonization of fouling communities on test panels submerged during different seasons. Barnacles, tubeworms, ascidians and seaweeds were the major fouling communities that colonized the test panels. The total biomass of the fouling communities that settled on the post-monsoon season panels varied from the initial value of 2.72 g dm−2 to a maximum of 44.5 g dm−2. On the panels submerged during monsoon season, the total biomass of fouling communities varied between 0.78 g dm−2 and 69.9 g dm−2. The total fouling biomass on the pre-monsoon season panels varied between 2.95 and 33.5 g dm−2. Barnacles were the initial colonizers on the panels submerged during pre-monsoon and post-monsoon seasons. Soft-bodied organisms such as ascidians dominated the monsoon season-initiated panel series during the initial period.  相似文献   

7.
A 31/2‐year succession of wharf‐pile fauna is described from communities of different known ages on piles at Lyttelton, New Zealand. Intertidal regions of the piles were initially colonised by the barnacle Elminius modestus; these populations developed to form a subclimax community which was subsequently replaced by a climax community of the mussel Modiolus neozelanicus after 21/2 years. The stability of this climax is discussed. In the infratidal region initial settlement of the tubicolous amphipod Corophium acherusicum and an erect bryozoan Bugula sp. was followed after 5 months by colonisation by solitary tunicates. These tunicates became dominant only after H years and provided numerous niches for superficial foulers, crevice dwellers, and motile organisms. This succession is compared and contrasted with a terrestrial succession of plants. Four vertical zones were recognised: supralittoral zone, midlittoral zone, in‐fralittoral fringe, and infralittoral zone. Species additional to those recorded by Skerman (1958) are appended.  相似文献   

8.
Abstract. The distribution and abundance of the hyperiid amphipods collected during April–May 1986 was analysed in order to study their relationship to mesoscale features in the southern Gulf of Mexico. Hyperiids were represented by 79 species, Lestrigonus bengalensis (65% of total hyperiids), Primno abyssalis (4.3%), Anchylomera blossevillei (2.3%) and Lestrigonus schizogeneios (2.3%) being the most abundant. Several mesoscale features (two cyclonic and three anticyclonic eddies, two upwelling areas) were active in the surveyed area. Cluster analysis of density and composition produced five groups of stations that were found to be related to some of these features. Overall, the mesoscale features that most influenced the local hyperiid community were the upwelling areas; they were related both with the highest and the lowest hyperiid densities and with high and low diversity figures. Overall day/night variations were normal, with highest night‐time densities; this pattern was not consistent in the different mesoscale features studied. Reverse migrations were possibly occurring, or migration patterns were lacking, at some of these systems. The hyperiid community structure related to the anticyclonic eddies differed somewhat among the eddies; however, the oceanographic exchange with the surrounding gulf waters probably obscured sharper faunistic differences between the communities.  相似文献   

9.
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10.
The spatial and temporal patterns within the surf zone epibenthic assemblages were studied in a coastal fringe of Argentina to determine whether assemblage compositions, abundance, species richness and diversity vary spatially and temporarily. Sampling was conducted seasonally in two sandy beaches over 2 years with a benthic sledge used to collect the fauna in the upper centimeters of soft bottom sediments and the epifauna on the sediment surface. Physical variables were measured in the same coastal sites where biological sampling was conducted. A total of 58 morphospecies were collected. Peracarid crustaceans were the most abundant group. The mysid Pseudobranchiomysis arenae (new genus–new species) (29.73 ± 17.79 ind. per sample) and the isopod Leptoserolis bonaerensis (51.54 ± 22.35 ind. per sample) were the most abundant and common species and were present regularly throughout the sampling period. Differences in the surf zone community composition were found between the beaches; these differences could be related to variation in physical parameters such as sand grain size and wave climate, indicating the possible influence of the morphodynamic state of the beaches on the epibenthic assemblages. A seasonal abundance trend was detected, reflecting the changes in abundance of the two dominant species; the richness pattern was not easily detectable due to the sporadic appearance of non‐resident species in the surf zone, probably due to different causes, including dispersion by entry of water from surrounding areas, littoral currents and storms. The surf zone studied presents a complex and dynamic epibenthic community that appears to be influenced by the morphodynamic state of the beach and the dynamic of non‐resident species.  相似文献   

11.
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12.
In the weeks following the 2011 Rena oil spill, a series of surveys was initiated on eight rocky intertidal reefs to describe the distribution of oil and to assess the impacts of oil on ecological communities. Consistent but relatively low cover of oil occurred at two sites (Mt Maunganui and Moturiki). The area covered by oil had decreased by c. 90% after 5 months due to natural weathering processes. There were immediate effects of oil fouling on the mussel Limnoperna pulex and its associated fauna, with reductions in the number of mussels and infaunal taxonomic richness. However, no ecological effects on any of the communities were detectable after 1 month. Overall, the ecological effects of the Rena oil spill on rocky shore intertidal communities were small and not long-lasting, but we stress that this does not consider potential sublethal effects and their consequences on organisms.  相似文献   

13.
Lately, across‐shore zonation has been found to be more important in structuring the nematode community of a tropical macrotidal sandy beach than microhabitat heterogeneity. To evaluate whether this zonation pattern applies to a temperate beach, a macrotidal ridge‐and‐runnels sandy beach in the North Sea was studied. We investigated whether a similar zonation occurs in sandbar and runnel microhabitats, and whether the runnels harbour a different community from the subtidal. Our results indicate that nematode communities from runnel and sandbar habitats are significantly different. In addition, horizontal zonation patterns for nematode communities differ between both habitats. Nematode assemblages from sandbars are divided to lower, middle and upper beach while upper and middle runnels cluster together. The subtidal and upper runnels showed dissimilar nematode assemblages, although runnels showed the same dominant species (Daptonema normandicum), which increases its abundance towards the upper runnels. This study illustrates the importance of microhabitat heterogeneity, which resulted in different zonation patterns across the sandy beach examined. The divergent zonation between sandbars and runnels in the macrotidal temperate sandy beach, compared with the pattern observed for a subtropical sandy beach with similar morphodynamics, indicates that generalizations about nematode distribution patterns should be made with caution.  相似文献   

14.
Abstract. Episodic events have been shown to strongly affect structure and function of marine benthic ecosystems. Severe storms can have profound effects on the distribution of marine sediments which could, in turn, influence the development of benthic communities. The rich and diverse epibenthic communities on the United States mid-Atlantic continental shelf owe their existence to the presence of a complex sequence of rocky outcrops. An unusually strong storm struck this shelf system in March 1993. Two of these carbonate platforms had been characterized by moderate sediment cover for at least the previous two years, but bottom water velocities generated by this storm removed considerable amounts of sediment from these upper flat hardbottom habitats. Macroalgal cover on these platforms dramatically increased between 1992 and 1993 with the increased exposure of hard substrate for attachment. The edges of the outcrops (scarps and rubble ramps), which are usually free of sediment, maintained their dense algal cover. Settlement blocks placed in various sub-habitats showed little variation in algal cover among flat hardbottom and scarp areas during both years, indicating that available hard substrate habitat may be the primary limiting factor for algal growth on the North Carolina continental shelf. Since macroalgal meadows provide food and shelter for juvenile fish, the increase in critical habitat following these storms may have implications for recruitment of economically important fish species. Thus, indirect effects of episodic storms, i.e ., redistribution of sand bodies leading to algal meadow development over large spatial scales, may have important consequences for benthic community development and persistence in temperate reef systems.  相似文献   

15.
Modes of colonization, the successional trajectory, and trophic recovery of a macrofaunal community were analyzed over 19 months in the Friendship marsh, a 20-acre restored wetland in Tijuana Estuary, California. Traditional techniques for quantifying macrofaunal communities were combined with emerging stable isotopic approaches for evaluation of trophic recovery, making comparisons with a nearby natural Spartina foliosa habitat. Life history-based predictions successfully identified major colonization modes, although most taxa employed a variety of tactics for colonizing the restored marsh. The presence of S. foliosa did not seem to affect macrofaunal colonization or succession at the scale of this study. However, soil organic matter content in the restored marsh was positively correlated with insect densities, and high initial salinities may have limited the success of early colonists. Total macrofaunal densities recovered to natural marsh levels after 14 months and diversity, measured as species richness and the Shannon index (H′), was comparable to the natural marsh by 19 months. Some compositional disparities between the natural and created communities persisted after 19 months, including lower percentages of surface-feeding polychaetes (Polydora spp.) and higher percentages of dipteran insects and turbellarians in the Friendship marsh. As surficial structural similarity of infaunal communities between the Friendship and natural habitat was achieved, isotopic analyses revealed a simultaneous trajectory towards recovery of trophic structure. Enriched δ13C signatures of benthic microalgae and infauna, observed in the restored marsh shortly after establishment compared to natural Spartina habitat, recovered after 19 months. However, the depletion in δ15N signatures of macrofauna in the Friendship marsh indicated consumption of microalgae, particularly nitrogen-fixing cyanobacteria, while macroalgae and Spartina made a larger contribution to macrofaunal diets in the natural habitat. Future successional studies must continue to develop and employ novel combinations of techniques for evaluating structural and functional recovery of disturbed and created habitats.  相似文献   

16.
The ecological impacts of introduced seaweeds have been relatively understudied. Current research suggests that seaweed invasions often result in alterations of native marine communities and disruptions of normal ecosystem functioning, but the effects on native communities can vary among invasive seaweed species, among habitats and over small and large spatial scales. In this study, the impacts of Sargassum muticum, a non‐native brown alga introduced into southern California, USA, several decades ago, were examined by comparing community structure in rocky inter‐tidal pools with and without the seaweed. Sargassum muticum appeared to have little impact on the native community despite measures revealing changes in the abiotic conditions of pools, with S. muticum presence reducing light penetration and ameliorating pool temperature changes during low tides. In other regions and habitat types, S. muticum presence often, but not consistently, resulted in declines in macrophyte diversity and/or abundance and increases in faunal assemblages. The lack of effects of S. muticum in this study, combined with variable impacts by S. muticum and other invasive seaweeds worldwide, suggests that predicting the effects of introduced seaweeds is problematic and warrants further research. Regardless of the effects on native communities, there is often a desire to eradicate or control the spread of non‐native seaweeds. In this study, localized S. muticum eradication attempts, including manipulations of a native canopy and herbivorous urchins, proved unsuccessful as full recovery occurred in ~9 months. While eradication efforts conducted worldwide have resulted in mixed success, there is a trend that early detection and rapid response can increase success, highlighting a need for systematic monitoring and establishment of regional rapid response plans.  相似文献   

17.
The colonization features of periphytic diatoms were studied in coastal waters of the Yellow Sea, northern China from May to June 2010, using glass slides as an artificial substratum. Samples were collected at a time interval of 1, 3, 7, 10, 14, 21 and 28 d from two depths of 1 and 3 m. The dynamics of diatom colonization process had a similar pattern in community structure and fitted the logistic model in growth curve at both depths. The maximum abundance and the time for reaching 50% maximum abundance （10 d） showed no significant differences （P〉0.05） between two depths 1 and 3 m. Although the diatom communities repre- sented similar taxonomic composition, they differed in the temporal pattern of structural parameters and in succession dynamics of dominant species between the two layers. The species richness showed significantly higher values during the colonization period more than 14 d, while the species diversity and evenness rep- resented a higher variability with significantly different values （P〈0.05） at a depth of 1 m than at a deeper layer. The results suggest that the diatom colonization follows the logistic model growth curve and differs in colonization features between different depths in the coastal waters, and that the sampling strategy at i m is more effective to detect the ecological features for bioassessment in marine ecosystems.  相似文献   

18.
Soft‐bottom macrobenthic communities of Manukau Harbour,New Zealand   总被引：1，自引：1，他引：0  
A survey of the macrobenthos at 42 stations in the channels and subtidal sandflats in Manukau Harbour, Auckland, revealed four biotic associations; although referred to as communities, they are not equivalent to Peterson‐type communities since they are not particularly discrete and there is some overlap in species composition. The similarity in species between stations was measured by percentage similarity coefficients using Jaccard's coefficient for presence‐absence data and Czekanowski's coefficient for log‐transformed quantitative data. Stations were grouped in dendrograms by group‐average sorting which allowed re‐arrangement of the similarity matrices into trellis diagrams.

Dominant species in each of the four groups of stations were ranked by calculating a ‘community score’ for each, based on its abundance, fidelity, and bioindex value within the group. Each of the four groups was found to support a unique group of species and these are considered as representing four communities. Two indicator species in each community were identified from the highest community scores: Group 1, the Microcosmus/Nolomithrax community — associated with a coarse sediment of dead bivalve shells and small rocks in shallow water. It has high species diversity indices; Group 2, the Halicarcinus/Bugula community— associated with a relatively coarse sediment of dead shells, grit, and little sand in deep water in the main channels; Group 3, the Amalda/Myadora community—associated with fine sand with mud or shell grit in shallow parts of the channels; and Group 4, the Fellaster/Pagurus community — associated with ironsand in shallow water in the outer harbour. It has low species diversity indices.  相似文献   

19.
洋山港海域大型污损生物生态特点   总被引：4，自引：2，他引：2  
洋山港是上海国际航运中心的枢纽港。为了解该海域污损生物的群落结构及演变趋势,2009年3月至2010年3月在洋山港海域进行了周年污损生物挂板调查研究。洋山港海域污损生物种类较少,共记录污损生物19种,隶属于5个类群,优势种为僧帽牡蛎(Ostrea cucullata)、网纹纹藤壶(Balanus reliculatus) 、大室膜孔苔虫(Membranipora grandicella)、厦门华藻苔虫(Sinoflustra amoyensis)、双钩楯琥珀苔虫(Aspidelectra bihamata)、中胚花筒螅(Tubularia mesembryanthemum)、曲膝薮枝螅(Obelia geniculata)和亚洲帚毛虫(Sabellaria ishikawai),种类组成以广布种为主,同时部分具有河口低盐种的特征;污损生物的附着高峰期是6—10月份,除冬季月份外,其余月份均有生物附着;受盐度、水流及泥沙含量的影响,洋山港污损生物的生物量变化较大,月板、季板及年板的平均附着生物量分别为9.20,127.20和774.04 g/m2。另外,通过对洋山港海域污损生物周年的物种组成和群落结构变化分析,发现该海域污损生物群落受季节变化和盐度的升高影响较大,群落结构不稳定,物种演替明显。  相似文献   

20.
The spatial and temporal biomass distribution of Chaceon affinis and its vulnerability to fishing activity in Gran Canaria (Canary Islands) were investigated. The first goal was to assess the influence of the slope steepness and substrate on the size of crab patches, size of the crabs, and crab biomass. The second goal was to evaluate spatial and temporal variation in the biomass over a 15‐month period. The last goal was to assess the influence of fishing activity upon the reduction in the biomass over the same 15‐month period. Only two or three locations in the sampling area generated high‐biomass contour patches. When these patches were superimposed on the isobath lines, they were coincident with the main depth range described for the species in the area. The map of the biomass values clearly showed three structures with cores of the highest biomass in both muddy and rocky‐muddy areas. The biomass was higher on muddy than on rocky‐muddy bottoms. Biomass was twice as high when steepness was reduced to one third between isobaths of 500 and 900 m. The size of crab patches increases linearly with the decrease in slope steepness. The spatial structure of crabs remained fairly stable over time, showing that biomass changes with depth over time. Maps of the estimated biomass values over the 15‐month period showed the same two main patches over time with the cores of highest biomass separated by a distance of between 4.2 and 4.5 km. Although the bathymetric distribution by sexes showed temporal changes, with a displacement to deeper areas made by both sexes over the studied period, only a partial temporal segregation between males and females was observed. During the study period, crabs underwent a significant decline in biomass and this was consistent with the combined catches of both commercial and experimental fishing in the area. Due to its low mobility, C. affinis is highly vulnerable to local depletion by intensive fishing efforts.  相似文献   

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