Invertebrate communities associated with hard bottom habitats in the South Atlantic Bight

Epibenthic invertebrates associated with nine hard bottom areas in the South Atlantic Bight between South Carolina and northern Florida were collected with dredge, trawl, suction and grab samplers to evaluate species composition, biomass, abundance, diversity, spatial distributions, and seasonality (winter and summer). Species composition changed noticeably with depth and season. Inner and outer shelf stations were least similar in species composition. Middle shelf areas were transitional and contained taxa characteristic of both inner and outer sites. Bryozoa (88 taxa), Cnidaria (85 taxa), Porifera (67 taxa), Annelida (261 taxa) and Mollusca (203 taxa) represented the richest taxonomic groups of the 1175 taxa collected. Both diversity (1175 total taxa) and biomass (1995 kg total) of invertebrates from hard bottom areas exceeded those reported in the literature for sand bottom communities. Sponges accounted for >60% of the total invertebrate biomass collected by dredge and trawl during both seasons. High diversity values were attributed primarily to habitat complexity and did not exhibit any discernible pattern with depth or latitude.     

珠江口浮游动物的群落动态及数量变化

根据2002年4月至2003年6月珠江口10个航次的调查资料,分析了丰水期(4—9月)和枯水期(10—3月)浮游动物的种类组成、优势种、群落结构、丰度和生物量的时空变化。经鉴定共有终生浮游动物71种和阶段性浮游幼虫7个类群。刺尾纺锤水蚤Acartia spinicauda是丰水期和枯水期皆出现的优势种。调查区的浮游动物可划分为河口类群、近岸类群、广布外海类群和广温广盐类群。丰水期浮游动物的平均丰度(1 131 ind.m-3)高于枯水期(700 ind.m-3),枯水期浮游动物的平均生物量(382 mg.m-3)高于丰水期(203 mg.m-3),浮游动物的丰度和生物量呈明显的斑块状分布。盐度是影响浮游动物种类、丰度和生物量分布的主要因素。     

The zooplankton community of the Mpenjati Estuary, a South African temporarily open/closed system

The aim of this study was to examine spatial and temporal variability in zooplankton abundance and biomass, both during the closed (dry season) and open (wet season) phases of the Mpenjati Estuary, South Africa. On average, nighttime abundance values were 1–3 orders of magnitude higher than daytime values. A total of 51 and 36 zooplankton taxa were identified during the open and closed phases, respectively. The estuarine species Pseudodiaptomus hessei, Acartia natalensis and Gastrosaccus brevifissura dominated the assemblage during both phases. During the open phase marine zooplankton species entered the estuary and increased the zooplankton species diversity. At the same time, the biomass of the estuarine zooplankton species decreased substantially due to scouring of the sediment, increase in salinity and turbulence, and possibly also in grazing pressure. Conversely, during the closed phase the zooplankton diversity decreased, since no marine organisms entered the estuary, but the biomass of typical estuarine species increased due to the stability of the estuary. The fluctuations in the zooplankton community structure between the closed and the open phases suggest that the opening and the closing of the estuary are very important processes in determining the food web of the estuary.     

Distribution of the plankton assemblages during the winter and summer along the southern coast of the Kerkennah Islands (Tunisia,Eastern Mediterranean Sea)

We studied the distribution of microphytoplankton, ciliates and mesozooplankton in relation to environmental factors in the coastal waters around the Kerkennah Islands. Diatom species were more abundant in winter, representing 74% of the total microphytoplankton abundance, whereas dinoflagellate abundance was higher in summer (58%). Naked ciliates dominated during the winter (73%) and loricate ciliates dominated during the summer (67%). Copepods were the most abundant mesozooplankton group present during the entire period of study, comprising 93%–98% of the total mesozooplankton community. The results indicate that (i) species distribution differed significantly between winter and summer, (ii) environmental factors such as temperature, salinity and nutrients influenced plankton assemblages; and (iii) the highest abundance of several pollution indicator species was due to direct exposure to the polluted coast of Sfax and the effect of tidal asymmetries generating nutrient‐rich inputs from the city.     

珠江口枯水期和丰水期中小型浮游动物群落动态

根据珠江口枯水期(2013年11月)和丰水期(2014年8月) 24个站位调查资料,对中小型浮游动物种类组成、丰度分布、群落结构及其主要影响因子进行了研究.结果表明,枯水期和丰水期分别鉴定浮游动物成体91种和70种,以桡足类最为丰富.浮游动物种类从河口上游向外围逐渐增加.浮游动物丰度时空分布差异显著,丰水期平均值高达11 619. 78 ind/m~3,显著高于枯水期的1 707. 13 ind/m~3.桡足类在珠江口中小型浮游动物中占绝对优势,枯水期和丰水期分别占总丰度的80. 3%和93. 0%,对浮游动物的丰度分布起关键作用.强额孔雀哲水蚤(Parvocalanus crassirostris)、中华异水蚤(Acartiella sinensis)和刺尾纺锤水蚤(Acartia spinicauda)在两个水期均为主要优势种,小拟哲水蚤(Paracalanus parvus)和厦门矮隆哲水蚤(Bestiolina amoyensis)则分别在枯水期和丰水期具有较高的优势度.聚类分析的结果显示,枯水期和丰水期该水域浮游动物均可划分为3个群落.相关性分析表明,珠江口中小型浮游动物群落结构受多个环境因子的影响,但盐度是其中最为关键的非生物因子.     

Trophic structure of zooplankton in the Fram Strait in spring and autumn 2003

The trophic structure of zooplankton was investigated in Fram Strait (north western Svalbard) in spring and autumn of 2003. Depth-stratified zooplankton samples were collected at 12 stations on the shelf (200 m), across the shelf-slope (500 m) and over deep water (>750 m), using a Multiple Plankton Sampler equipped with 0.180-mm mesh size nets.Higher zooplankton abundance and estimated biomass were found in the shelf area. Abundance and biomass were two times higher in August, when sea-surface temperature was higher than in May. Herbivores dominated numerically in May, and omnivores in August, suggesting a seasonal sequence of domination by different trophic groups. Cirripedia nauplii and Fritillaria borealis prevailed in spring, whereas copepod nauplii and Calanus finmarchicus were numerically the most important herbivores in autumn. Small copepods, Oithona similis and Triconia borealis, were the most numerous omnivorous species in both seasons, but their abundances increased in autumn. Chaetognatha (mainly Eukrohnia hamata) accounted for the highest abundance and biomass among predatory taxa at all deep-water stations and during both seasons. Regarding vertical distribution, herbivores dominated numerically in the surface layer (0–20 m), and omnivores were concentrated somewhat deeper (20–50 m) during both seasons. Maximum abundance of predators was found in the surface layer (0–20 m) in spring, and generally in the 20–50 m layer in autumn. This paper presents the first comprehensive summary of the zooplankton trophic structure in the Fram Strait area. Our goals are to improve understanding of energy transfer through this ecosystem, and of potential climate-induced changes in Arctic marine food webs.     

Phytoplankton driven distribution of dissolved and particulate lipids in a semi-enclosed temperate sea (Mediterranean): Spring to summer situation

The relationship between changes in lipid classes and phytoplankton composition and abundance in the northern Adriatic was studied during spring and summer 2008 at two stations with different nutrient levels, i.e. at the western mesotrophic and eastern oligotrophic areas. Changes in the phytoplankton community depended on temporal surface nutrient depletion and bottom accumulation; that is, microphytoplankton, mainly diatoms Pseudo-nitzschia sp., developed at nutrient richer surface layers of the mesotrophic area in spring and at deeper layers of the oligotrophic site in late summer. In other periods nanophytoplankton dominated. Dissolved organic carbon (DOC) and lipid content were comparable for the two stations, while particulate organic carbon (POC) was richer at the mesotrophic side. Total lipid concentrations varied in the range from 8.0 to 92.2 μg l⁻¹ and from 16.9 to 76.9 μg l⁻¹ in the dissolved and particulate fractions, respectively. DOC and POC contents were in the ranges from 0.77 to 1.58 mg l⁻¹ and from 0.06 to 0.56 mg l⁻¹, respectively. Lipid and organic carbon distribution did not follow phytoplankton progression, indicating decoupling between organic matter production and decomposition throughout the investigation period. The main sources of lipids were marine phytoplankton and bacteria. Low nutrient conditions caused increased biosynthesis of lipids. Also, increasing oligotrophy led to an increasing number of phytoplankton taxa. The synthesis and accumulation of glycolipids by the developed taxa were enhanced during nutrient exhaustion, contributing in late summer, on average, 20.2 and 22.0% at the mesotrophic and oligotrophic stations, respectively, in the particulate fraction. The distribution of bacterial lipids and lipid breakdown products implies that bacterial lipid degradation was significant in spring, while very probably lipid abiotic degradation took place during summer.     

Changes in biomass structure and trophic status of the plankton communities in a highly dynamic ecosystem (Gulf of Venice,Northern Adriatic Sea)

The changes in the plankton biomass structure in relation to nutrient inputs were studied in the Gulf of Venice (Northern Adriatic Sea), an area characterized by a very marked trophic state variability. The investigation was carried out at two stations, in March, May and July 2005 and 2006, considering the whole water column. The size structure (from picoplankton to mesozooplankton) of both autotrophs and heterotrophs was analysed. Signals of diluted waters and nutrient inputs were more marked in 2005 than in 2006. In 2005, the total plankton biomass was almost double (87 ± 37 μg·C·l^?1) that in 2006 (44 ± 26 μg·C·l^?1). The variations were determined mainly by phytoplankton, with a 70% decrease, and a shift from a community dominated by microphytoplankton (49 ± 12%) in 2005 to one dominated by bacteria (43 ± 11%) in 2006 was observed. The relationship between the heterotrophic (H) and autotrophic (A) biomass indicated a rapid decline of the H/A ratio with increasing phytoplankton biomass. This study, although temporally limited, is consistent with the results reported for other marine environments and it seems to confirm the importance of nutrient inputs in structuring the biomass of plankton community.     

钦州湾丰水期和枯水期浮游动物群落特征

在2011年丰水期(7月)和2012年枯水期(3月),分别对钦州湾的内湾和外湾开展了浮游动物调查,研究了枯水期和丰水期钦州湾浮游动物的种类组成、数量分布和季节变化特征。丰水期和枯水期浮游动物种类数量分别为27种和44种,以优势度指数Y0.02确定的优势种丰水期和枯水期分别为3种和4种。丰水期浮游动物丰度为4.0~133.6ind/m3,平均丰度为50.9ind/m3;枯水期浮游动物丰度为1.2~1 725.0ind/m3,平均丰度为272.2ind/m3。丰水期浮游动物(包含鱼卵仔鱼)生物量为1.7~179.2mg/m3,平均生物量为44.0mg/m3;枯水期浮游动物(包含鱼卵仔鱼)生物量为3.1~3 530.0mg/m3,平均生物量为474.9mg/m3。无论是浮游动物的种类数量、丰度和生物量,均显示出内湾低于外湾的空间分布特征,以及枯水期高于丰水期的变化特征。钦州湾浮游动物的这种季节变化和空间分布特征主要是与浮游植物生物量、贝类养殖、环境的稳定度以及人为干扰等有着密切的关系。     

Succession patterns of polychaetes on algal‐dominated rocky cliffs (Aegean Sea,Eastern Mediterranean)

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.     

Taxonomic composition,abundance and biomass of mesozooplankton in the Zhelin Bay-an estuary with intensive aquaculture

1 IntroductionMesozooplankton (0.2 ~20 mm) are hetero-trophic animals that inhabit almost every type of ma-rine environment (Goswami and Padmavati, 1996;Uye et al., 1996). They are major secondary pro-ducers, grazing on phytoplankton and providing foodfor…     

The Larval Fish Assemblage in Nearshore Coastal Waters off the St Lucia Estuary, South Africa

This paper reports on the composition, abundance and distribution of the larval fish assemblage in the nearshore coastal waters off the St Lucia Estuary mouth, South Africa. Ichthyoplankton samples were collected over a 12 month period from five stations located along a transect up to 2·5 km offshore, and from two stations north and south of the estuary mouth, respectively. In all, 6126 fish larvae, representing 89 families and 186 species, were collected. Larvae in the families Myctophidae and Tripterygiidae comprised 21% and 16% of the total catch, respectively. The most abundant species were an unidentified triplefin, Tripterygiid 1 and the lanternfish Benthosema fibulatum, together which contributed nearly 18% of the total catch. Larvae of marine spawners independent of estuaries dominated the catch both in terms of density (90%) and in terms of number of taxa (89%). Some larvae of estuarine-associated species were present, in addition to a few specimens of estuarine resident species. Overall the dominant environmental variable affecting larval densities was temperature, particularly for Trypterygiid 1 where temperature contributed to 9% of the variance model. Densities of fish larvae peaked in November and December 1990 (late spring and early summer) and were lowest from January to June 1991 (summer, autumn an early winter). Different taxa dominated the catch each month with reef- and shelf-associated species accounting for the peak in August and September 1990, oceanic species in November 1990 and a mixture of the two groups in December. Overall larval densities were significantly higher in bottom samples with a trend of increasing densities offshore for reef and shelf taxa. The larvae of reef and shore taxa were predominantly preflexion larvae, whilst the few estuarine spawner species that were collected were mainly postflexion. Ontogenetic patterns related to depth and distance offshore were evident for the dominant species in each estuarine-association category.The present study has shown that temporal and spatial variations in the larval fish assemblage off St Lucia are related to environmental conditions and ontogenetic behavioural patterns of certain species. The origin of many of the larvae in the assemblages off the coast of St Lucia is probably from both local spawning populations in the shelf waters off KwaZulu-Natal and spawning populations farther north in shelf waters off Mozambique. Additional studies with more detailed oceanographic measurements will further our understanding of the physical processes that supply larvae to the St Lucia region.     

粤西近岸海域浮游植物群落的生态特征

作者基于2011年9月(丰水期)和2012年1月(枯水期)粤西近岸30米以浅海域的调查资料,分析该海域浮游植物的种类组成、优势种、丰度及其群落结构多样性。结果表明,调查海域共鉴定浮游植物4门41属116种,硅藻为最主要优势类群。丰水期与枯水期共有种类40种,物种相似性指数为34.48%,表明2个调查季节种类组成变化较大,存在明显的季节性差异。枯水期优势种仅1种,为金藻门(Chrysophyta)的球形棕囊藻(Phaeoecystis globosa),优势度高达0.496;丰水期优势种有4种,其中以硅藻门的旋链角毛藻(Chaetoceros curvisetus)优势度较高(0.249)。浮游植物丰度表现出时间和空间异质性,丰度总体呈现近岸站位高于离岸站位,此外,丰水期浮游植物丰度湛江沿岸站位高于其他调查站位,枯水期浮游植物丰度则由西南部向东北部递减,总体而言,枯水期浮游植物丰度比丰水期高。群落结构多样性为枯水期西南部海域明显低于东北部海域,丰水期站位间多样性无明显变化规律,相比之下,丰水期群落物种多样性水平相对较高。相关分析表明:浮游植物丰度与p H、悬浮物呈正相关,与丰水期水温和枯水期盐度呈负相关。     

Autumn living coccolithophores in the Yellow Sea and the East China Sea

An investigation was carried out on living coccolithophores(LCs) distribution in the Yellow Sea and the East China Sea from October 17 to November 24, 2011. A total of 223 samples from different depths were collected at 48 stations. Totally 18 taxa belonging to coccolithophyceae were identified using a polarized microscope at the 1 000× magnification. The maximum species abundance was found at the outside of Transect P. The dominated species were Gephyrocapsa oceanica, Emiliania huxleyi, Helicosphaera carteri, and Algirosphaera robusta. The abundance of coccoliths and cells ranged 0–2 965.73 coccoliths/mL, and 0–119.16 cells/mL, with the average values of 471.00 coccoliths/mL and 23.42 cells/mL, respectively. The LCs in surface layer were mainly observed on the coastal belt and middle part of the survey area. The comparison among Transects A, F, P and E indicated lower species diversity and less abundance in the Yellow Sea than those of the East China Sea. The highest abundance of LCs was found in transect F and P. The coccolith abundance increased slightly from surface to bottom in the water column, but the highest value of the cell abundance was observed in the depth of 10–30 m. Temperature, depth and nutrient concentration were suggested as the major environmental factors controlling the distribution and species composition of LCs in the studying area based on canonical correspondence analysis(CCA).     

2005～2006年珠江口浮游动物群落变化研究

根据2005年4月至2006年9月珠江口4个航次19个站位的调查资料，分析了春、夏季和秋季初浮游动物的种类组成、优势种和个体数量等的时空变化，并分析了研究期间浮游动物群落的演替情况．经鉴定共发现终生浮游动物226种和阶段性浮游幼体5个类群．优势种中，除了刺尾纺锤水蚤（Acartia spinicauda）、强额拟哲水蚤（Paracalanus crassirostris）和中华异水蚤（Acartiella sinensis）等过去常见的优势种外还出现枝角类和被囊类的种类，夜光虫（Noctiluca scintillans）则是春季的第一优势种．调查海区的浮游动物可划分为河口类群、近岸类群、大洋类群和广温广盐类群．2006年浮游动物的平均个体数量高于2005年，春季的平均个体数量高于同年夏季或秋季初，空间分布则无明显规律．根据相关分析，盐度和水温是影响该海区浮游动物群落结构的重要因素．根据演替速率E值的计算结果，珠江口浮游动物群落存在明显的季节演替，但2005年至2006年间的同一季节则未出现显著的群落演替。     

Distribution and feeding modes of macrobenthos within three oceanographic feature areas of the KwaZulu-Natal Bight,South Africa

The composition and distribution of macrobenthic communities was investigated in three areas in the KwaZulu- Natal Bight, a section of shelf off the east coast of South Africa. Areas were pre-selected on the basis of three known oceanographic features, posited to deliver land- or Agulhas Current-derived nutrients onto the shelf and to drive ecosystem functioning in this region. Replicate sediment samples were collected with a 0.2 m² van Veen grab, during two surveys (A, B) corresponding with normal periods of high and low rainfall, respectively. A subset of the full station array was selected across the shelf in an arrangement of increasing depths (inner-, mid- and outer shelf) through each feature area to investigate the spatial distribution and feeding modes of macrobenthic taxa. The two periods showed some differences in abundance and numbers of macrobenthic taxa, but were not statistically different. Total macrobenthic abundance from Survey A was 20 215 individuals from 642 taxa, decreasing to 18 000 individuals from 503 taxa during Survey B. Polychaeta and Crustacea were the dominant taxa sampled; abundance of the latter was attributed largely to a proliferation of Paguristes sp.1 at inner-shelf samples in the midbight (Thukela) region during Survey B. Similarity classification distinguished seven sample groups reflecting differences in feature areas and shelf positions under investigation. The Thukela River midshelf community supported the highest macrobenthic abundance, while the midshelf off the southern bight (Durban region) was most species rich. Findings were attributed to the habitat complexity of the midshelf which includes a palaeo-dune cordon at the 60 m isobath. Functionally, the community was dominated by interface- and deposit-feeding fauna, emphasising the importance of trophic plasticity in an environmentally variable and heterogeneous shelf environment.     

Larval fish distribution in shallow coastal waters off North Western Iberia (NE Atlantic)

Monthly sampling for ichthyoplankton was conducted at three stations very near to the coast (near to shore shallow stations before the surf zone in direction to the shoreline) of Atlantic northwestern Portugal within contrasting localities: rocky shore, in front of a sandy beach receiving an estuary and a fishing port with heavy anthropogenic impact. Sampling was conducted from August 2002 to October 2003, always at full moon, at low tide and high tide in daylight hours, at the water column using a 48 cm diameter plankton net with 335 μm mesh. Analysis of the physico-chemical parameters pointed out the spatial (horizontal) homogeneity of the sampling area. Fish larvae from 41 taxa belonging to 17 families were identified; Blenniidae, Labridae, Ammodytidae, Clupeidae, Gobiidae, Soleidae and Gobiesocidae were the most representative during the study period. Parablennius gattorugine, Ammodytes tobianus, Symphodus melops, Sardina pilchardus, Lipophrys pholis and Coryphoblennius galerita were the most representative species (percentage contribution to total abundance). Peak abundance of fish eggs occurred during May, June and August 2003 and fish larvae occurred during May and July 2003 and August 2002 and 2003; there was a pronounced winter/early spring (March 2003) peak in larval abundance dominated by the small sandeel A. tobianus. This study identifies the occurrence of a conspicuous assemblage of larval fishes at very nearshore shallow environments of a variety of species with different adult habitats: the fish larvae assemblage was dominated by intertidal species. The present study has shown that temporal and spatial variations in the larval fish assemblage are related to environmental conditions and biological dynamics: the results suggest that abiotic conditions mediate biotic parameters, and that both abiotic and biotic characteristics regulated the larval fishes at very nearshore shallow environments.     

AN ECOLOGICAL STUDY OF BENTHIC ORGANISMS IN THE NEARSHORE WATERS TO THE WEST OF TAIWAN STRAIT

In seven cruises on benthic organisms in the nearshore waters(>50 m) to the west of the Taiwan Strait(23°20''-25°54''N,117°11''-119°58''E) in 1961-1964,altogether 189 stations of quantitative grabbing and 33 stations of qualitative trawling were made.
Altogether 392 species of benthic organisms have been identified.The composition was dominated by nearshore shallow water species,with tropical and subtropical species absolutely dominant.The total average of biomass was 38.0 g/m² and average density,116.0 ind./m².The communities of benthic organisms in the area can be classified into five communities namely,(1) Amphiura sp.-Acaudina molpadioides Community;(2) Protankyra asymmetrica-Arnphioplus pracstans-Murex trapa Community;(3) Modiolus meicalfei-Phyllophorus liuwutiensis-Armandia letocirris-Nephtys sinensis Community;(4) Branchiostoma belcheri-Solenr oseomaculatus-Marphysa sinensis- Onuphis eremita Community;(5) Iconomtra japonica-Barbatia decussata Community.     

Diet composition and resource partitioning in two small flatfish species in the German Bight

Since the late 1980s, the small-sized non-commercial flatfish species solenette (Buglossidium luteum) and scaldfish (Arnoglossus laterna) have increased in abundance in the southern North Sea. Because these species are considered as possible competitors for prey of commercial flatfish, this study aimed at advancing knowledge of their feeding ecology.Between January 2009 and January 2010 stomach contents of solenette and scaldfish and benthic infauna were sampled seasonally in a study area in the German Bight. The objectives were to investigate the seasonal variability of feeding activity and diet composition of both flatfish species related to benthic prey availability.For both flatfish, the highest feeding activity was found in summer, at the same time that the highest prey densities occurred in the study area. A reduced feeding activity was observed during the winter of 2010, but not in the winter of 2009, probably related to higher 2009 water temperatures.In all seasons, diet composition of solenette was dominated by meiofauna, mainly harpacticoid copepods. Macrofauna prey species, namely juveniles of bivalves and echinoderms became important in spring. An increase in amphipods and cumaceans was found in the stomach contents during summer and autumn, simultaneously with their increased abundance in the benthic infauna. In contrast, polychaetes were rarely found in the diet, but dominated the infauna during all seasons.Diet composition of scaldfish was dominated by larger and mobile prey, and, during all seasons, was mainly comprised of crustaceans. Amphipods characterised the diet in both winters, while decapods such as Crangon spp. and Liocarcinus spp. were the dominant prey from spring to autumn. Additionally, juveniles of flatfish (Pleuronectids) and bivalves were found in the scaldfish diet in spring, replaced by cumaceans in summer. No dietary overlap between both flatfish species was found across seasons, indicating partitioning of prey resources between solenette and scaldfish. Their different feeding strategies and prey preferences, in turn were influenced by the seasonal variability of available prey.     

浙江檀头山岛周围海域夏、秋季大型底栖动物群落结构特征

为揭示现阶段浙江檀头山岛周围海域大型底栖动物群落现状,于2013年7月、2013年11月对该海域进行了2航次的大型底栖动物生态调查,20个采样站位共获得大型底栖动物55种,其中甲壳动物最多,有18种(占32.73%),其次是底栖鱼类(17种,占30.91%)、软体动物(16种,占29.09%),腔肠动物3种(5.45%),环节动物最少,只有1种(1.82%)。2航次共鉴定大型底栖动物优势种14种,其中葛氏长臂虾Palaemon gravieri、细巧仿对虾Parapenaeopsis tenella为2航次共有优势种,其余均为单一航次优势种,夏、秋季间种类更替率较高,为51.85%。平均生物量、丰度,夏季航次均分别高于秋季航次,方差分析表明生物量、丰度两航次间均存在显著差异(P0.05),远近岸间均不存在显著差异(P0.05)。对檀头山岛周围海域夏季和秋季大型底栖动物群落结构进行聚类分析和n MDS排序分析,结果表明,夏季、秋季20个站位均可划分成2个主要聚类组,对各聚类组内平均相似度贡献较大的物种主要是广温、广盐性的甲壳类动物,如东方口虾蛄Oratosquilla oratoria、中国毛虾Acetes chinensis、细螯虾Leptochela gracilis、葛氏长臂虾Palaemon gravieri、中华管鞭虾Solenocera crassicornis、三疣梭子蟹Portunus trituberculatus等。ABC曲线和多样性指数分析表明,檀头山岛周围海域大型底栖动物群落在秋季受到重度扰动,夏季未受到扰动。粒径分析结果显示檀头山岛周围海域沉积物主要是由较细颗粒的黏土和粉砂组成。CCA分析结果表明温度、盐度、水深、溶解氧是对大型底栖动物影响程度较大的环境因子。