南麂列岛大沙岙沙滩贝类的时空分布

南麂列岛作为观光旅游的休闲去处正在日益升温,其中沙滩游玩是最大的活动亮点,大沙岙是南麂列岛最具代表性的沙滩,沙滩内生活着较多贝类,随大量人员的涌入和沿岸环境污染的日趋加重,大沙岙沙滩贝类的栖息地环境受到了较大程度的危害、人为活动正影响着贝类的生长发育。为探明近年来大沙岙贝类种类、数量及群落结构的变化,在南麂列岛国家海洋自然保护区建立初期(1992年)生态调查的基础上,于2003年再次对大沙岙贝类进行了采样分析,结果表明:大沙岙沙滩12种贝类的平均生物量和栖息密度分别为30.16g/m2和20个/m2,北断面开放区贝类的平均生物量和栖息密度(13.98g/m2和11个/m2)明显少于受监控的南断面核心区(46.33g/m2和30个/m2),贝类的平均生物量和栖息密度的垂直分布低潮区(48.43g/m2和31个/m2)高于中潮区(28.03g/m2和20个/m2),贝类的平均栖息密度7月高于3月,北断面贝类的季节变化、多样性和均匀度指数大于南断面。与建区初期同季调查资料比对发现,2003年北断面贝类数量下降幅度(14倍)显著大于南断面贝类下降幅度(1倍)。分析认为,自然环境变化和人为采捕是影响沙滩贝类数量下降的主要外部因子。     

Abundance,Tidal Movement,Population Structure and Burrowing Rate of Emerita analoga (Anomura,Hippidae) at a Dissipative and a Reflective Sandy Beach in South Central Chile

Abstract. To evaluate the effects of beach morphodynamics upon the abundance, tidal movement, population structure and burrowing rate of the crab Emerita analoga (Stimpson) (Anomura, Hippidae) we sampled two beaches in south central Chile (ca. 42° S), Mar Brava and Ahui with dissipative and reflective characteristics, res­pectively. The swash zone at the dissipative beach was 5 – 6 times wider than that of the reflective beach. A at the dissipative beach, upwash speeds were higher and the number of effluent line crossings were lower by more than an order of magnitude. To examine the tidal movement of E. analoga, we collected crabs from 5 to 6 tidal levels of each beach every 2 h across 12 h of the tidal cycle. The intertidal distribution of crabs differed between beaches; i. e., at the dissipative beach they were primarily located at the swash zone, while at the reflective beach they were mostly located at the low tide level and shallow subtidal. The change in position of crabs was pronounced across the tidal cycle at the dissipative beach (Mar Brava), with most of the animals remaining in the active swash zone. Body size data were used to construct size frequency distributions for each population. Crabs from the dissipative beach reached larger sizes than those at the reflective beach. Sediments were coarser at the latter versus the former beach. Crabs burrowed at similar rates in the sand from both beaches, a result which supports the idea that E. analoga is a “sediment generalist” capable of burrowing successfully in a wide range of sediment types. This characteristic is likely a key to the broad success of this species on the full range of beach morphodynamic types along the coasts of South and North America.     

全国海水浴场及经济贝类中腺病毒的分布

为分析全国海水浴场、贝类增养殖区人类肠道腺病毒的污染状况,采用超滤浓缩方法,TaqMan探针实时定量PCR技术对其进行了定量。结果表明,全国10个海水浴场表层海水中腺病毒的阳性检出率为35%,含量为1.1×107~2.8×107 copies/L。在离岸100m和1 000m处腺病毒的分布无显著差别(p0.05);在调查的162份贝类样品中,腺病毒的阳性检出率为11.7%,含量为2.4×104~3.1×105 copies/g。6类经济贝类中牡蛎带病毒量最高。由此可见,全国范围内海水浴场表层海水和主要增养殖区经济贝类中腺病毒污染比较普遍,尤其以山东、辽宁和浙江三省最为严重,给洗浴者和消费者健康造成潜在威胁。人类肠道腺病毒可以很好地指示粪便污染,调查其在海水浴场和经济贝类中的分布,可以帮助公众预警胃肠道病毒的暴发流行,本研究为开展全国腺病毒的环境风险评估和分子流行病学调查奠定了良好的基础。     

Population Abundances, Tidal Movement, Burrowing Ability and Oxygen Uptake of Emerita analoga (Stimpson) (Crustacea, Anomura) on a Sandy Beach of South-Central Chile

Abstract. Field sampling and other experiments were carried out during February 2001 to determine whether different morphodynamic characteristics occurring within an intermediate sandy beach of southern Chile (ca. 39°S) convey differences in population abundance, tidal movement, burrowing ability and oxygen uptake of the anomuran crab Emerita analoga (Stimpson, 1857). Crabs were collected along transects extended between the lowest swash levels and the retention zone above the effluent line of the south and north end of the beach. Burrowing times of nearly 70 crabs collected at each study site were measured in saturated sands collected from the lowest swash level of each site. Oxygen uptake of crabs was measured in incubation glass bottles. The intertidal zone of the north end of the beach was wider (56 m) and flatter (1/14) than that of the south end (45 m and 1/9, respectively). In general, the swash zone of the north end was significantly wider than the south end throughout the sampling period. The frequency of swashes and number of swash crossings above the effluent line, plus up‐wash speed, were usually higher at the steeper south end of the beach. The mean population abundance of E. analoga per linear metre of beach was significantly higher at the north end, whereas density per square metre was significantly higher at the south end. No differences were found in biomass figures. Although the highest abundance of crabs at the north end was usually observed at the lowest swash levels, similar population abundances occurred along all the tidal levels sampled at the south end. Burrowing times of crabs collected from both ends of the beach increased significantly with increasing carapace length and body mass. The mean burrowing time of crabs collected at the south end of the beach was shorter than that of those collected at the north end. Oxygen uptake of E. analoga was positively and exponentially correlated with the size of individuals collected from both ends of the beach. Results of ANCOVA showed no significant difference between the regression lines obtained for the oxygen uptake of crabs collected at both ends of the beach. It is concluded that physical features of each end of the beach seem not to differ enough to produce differences in oxygen uptake of E. analoga, or in the biomass, population structure and body size of crabs, within a single beach of south‐central Chile.     

北部湾涠洲岛珊瑚礁底栖贝类的群落特征

珊瑚礁是全球生物多样性最高的海洋生态系统之一,底栖贝类是该生态系统的重要组成类群。为了解北部湾涠洲岛珊瑚礁底栖贝类的群落现状及特征,于2015年秋季(10月)与2018年春季(5月)采用水肺潜水截线样条定量调查法对涠洲岛珊瑚礁区6个断面的底栖贝类进行了调查,并分析了物种组成、丰度、生物多样性指数等群落特征。综合两次调查结果显示涠洲岛珊瑚礁区共有底栖贝类128种,分别属于多板纲1科1属3种,腹足纲25科46属68种,双壳纲22科31属57种。优势种为斑顶拟舌骨牡蛎、粗衣蛤、刺荔枝螺、马蹄螺、杂色牙螺、青蚶、旗江珧、甲虫螺、蕾丝蟹守螺、珠母爱尔螺。2018年春季定量断面采集到的样品为2纲14科43种,各断面的丰度、生物量、多样性指数、物种丰度指数和均匀度指数均值分别为3.39个/m2、86.94 g/m2、3.31、3.50、0.37。通过对两年的调查数据比较,发现2015?2018年涠洲岛珊瑚礁区的贝类生物群落呈现良好演替发育趋势。南海珊瑚礁区贝类群落结构可能受到了人为干扰强度和纬度的双重影响。本研究全面掌握了涠洲岛珊瑚礁底栖贝类的种类、分布区及群落的结构与变化,可为该地区海洋生物资源开发利用、珊瑚礁保护和生态修复等工作提供数据支持。     

An overview of beach morphodynamic classification along the beaches between Ovari and Kanyakumari,Southern Tamilnadu Coast,India

Beach morphology relates the mutual adjustment between topography and fluid dynamics. The morphological makeup of beach systems is not accidental because the arrangement and association of forms occur in an organized contextual space and time. Since the classification derived by Wright and Short (1983) from the analysis of the evolution in a number of Southern Tamilnadu beach sites, beach systems are comprehended in terms of three-dimensional morphodynamic models that include quantitative parameters (wave breaking height, sediment fall velocity, wave period, and beach slope) and boundary conditions for definable form-processes association (e.g., the presence or absence of bars as well as their types). This has led to the classification of beaches into three main categories relating the beach state observations with the physical forcing (Short, 1999) dissipative, intermediate (from the intermediate–dissipative domain to the intermediate-reflective domain), and reflective modes. The morphodynamic classification of beach types was based on the Wright–Short equations (1984) (dimensionless fall velocity–Dean parameter).     

福建闽南沿海养殖贝类体中砷含量的分布

通过2003~2004年对福建闽南沿海5种养殖贝类体砷含量的调查监测,对养殖贝类体中砷含量的分布进行了探讨.福建闽南沿海5种养殖贝类体总砷含量为0.65×10-6~4.80×10-6,总平均值为2.09×10-6,其中有机砷和无机砷占总砷含量的百分比分别为61.6%~98.2%和2.3%~38.4%,平均值分别为88.8%和11.2%.在相同养殖区,养殖贝类体总砷平均含量的种间分布差异较小.滩涂养殖底栖贝类体内总砷平均含量总体上高于浅海筏式养殖贝类体的平均含量.福建闽南沿海5种养殖贝类体内总砷含量在泉州湾、湄州湾、东山湾和九龙江口高,在诏安湾和围头湾低,在其余各湾相近.5种养殖贝类体内无机砷的污染指数和总平均值分别为0.05~0.76和0.23,总砷的污染指数和总平均值分别为0.06~0.48和0.21,总体符合国家食品卫生质量标准.养殖贝类体中砷含量与体长之间总体成正相关.     

Fish assemblage structure on sandy beaches with different anthropogenic influences and proximity of spawning grounds

Fish assemblages in an insular (preserved) and a continental (disturbed) sandy beach were compared to assess any changes that could be attributed to anthropogenic influences and/or the proximity of the fish spawning grounds. We expected that the closer geographical position to the spawning grounds and the small amount of anthropogenic disturbance on the insular beach would be likely to provide more suitable conditions for early fish development compared with the continental beach. A total of 192 samples (96 in each beach) were taken, yielding 68 fish species, mostly young‐of‐the‐year. Fish assemblage structure differed significantly between the two beaches. Moreover, the insular beach had higher number of species, number of individuals and biomass compared with the continental beach. The commercially important Clupeiformes Harengula clupeola, Anchoa tricolor and Anchoa januaria, Perciformes Micropogonias furnieri and Mugiliformes Mugil liza were typical species on the insular beach, partitioning the seasonal use of the beach. On the other hand, a few abundant non‐commercial species, mainly the Atheriniformes Atherinella brasiliensis and the Perciformes Eucinostomus argenteus and Diapterus rhombeus, occurred all year round at the continental beach. The high fish richness and abundance and the more conspicuous species turnover across seasons on the insular beach are probable indications of more complex and dynamic organization of the communities favored by better geographical position and less anthropogenic disturbance in the area.     

Relationships of rainfall,river flow,and salinity to faecal coliform levels in a mussel fishery

Faecal coliform levels were determined for sea water and shellfish flesh from farms of the green mussel, Perna canaliculus, in Pelorus Sound, Marlborough Sounds, New Zealand. Simple linear models were developed to relate logarithmically transformed data on the faecal coliform levels to measures of fresh water entering the mussel beds. These models support guidelines to restrict harvesting following periods of heavy rain in order to comply with shellfish sanitation standards. Alternative guidelines are suggested based on the volume of river water entering the sound or salinity.     

Sustainable shellfish aquaculture in Saldanha Bay,South Africa

The carrying capacity for bivalve shellfish culture in Saldanha Bay, South Africa, was analysed through the application of the well-tested EcoWin ecological model, in order to simulate key ecosystem variables. The model was set up using: (i) oceanographic and water-quality data collected from Saldanha Bay, and (ii) culture-practice information provided by local shellfish farmers. EcoWin successfully reproduced key ecological processes, simulating an annual mean phytoplankton biomass of 7.5 µg Chl a l^–1 and an annual harvested shellfish biomass of about 3 000 tonnes (t) y^–1, in good agreement with reported yield. The maximum annual carrying capacity of Small Bay was estimated as 20 000 t live weight (LW) of oysters Crassostrea gigas, or alternatively 5 100 t LW of mussels Mytilus galloprovincialis, and for Big Bay as 100 000 t LW of oysters. Two production scenarios were investigated for Small Bay: a production of 4 000 t LW y^–1 of mussels, and the most profitable scenario for oysters of 19 700 t LW y^–1. The main conclusions of this work are: (i) in 2015–2016, both Small Bay and Big Bay were below their maximum production capacity; (ii) the current production of shellfish potentially removes 85% of the human nitrogen inputs; (iii) a maximum-production scenario in both Big Bay and Small Bay would result in phytoplankton depletion in the farmed area; (iv) increasing the production intensity in Big Bay would probably impact the existing cultures in Small Bay; and (v) the production in Small Bay could be increased, resulting in higher income for farmers.     

珠江口香港海域底拖网贝类资源研究

珠江口海域是香港和广东的主要渔场之一,但有关该水域贝类资源的研究并不完善,本文可以为该海区调查位置的贝类资源现状提供参考,对完善该海区贝类的基础研究提供依据。作者于2016年2月和8月,对珠江口香港海域贝类资源进行了底拖调查,所采集软体动物隶属3纲、16目、26科,33属;2月份(枯水期)和8月份(丰水期)分别采集到贝类28种和39种。枯水期优势种为棒锥螺Turritella terebra、浅缝骨螺Murex trapa及波纹巴非蛤Paphia undulata,约占总个体数的86.9%;丰水期优势种是棒锥螺Turritella terebra、浅缝骨螺Murex trapa和牡蛎Ostrea sp.,约占总个体数的85.3%。多样性指数范围为0.9179~1.064。调查发现,8月份贝类的物种数量和生物量明显多于2月份,棒椎螺为该水域明显的优势种。     

Survey of historical New Zealand shellfish samples for accumulation of gymnodimine

In 1994 a major biotoxin event occurred along the east coast of the South Island, New Zealand. Gymnodimine, a unique bioactive spiroimine, was isolated and characterised from Foveaux Strait dredge oysters (Tiostrea chilensis = Ostrea chilensis) collected during this outbreak. This study reports the results of liquid chromatographic‐mass spectrometric analysis for gymnodimine in 217 samples from eight species of shellfish over the years 1993–99. Of these samples 155, covering six species of shellfish, contained detectable gymnodimine with a range in concentration from 14.8 to 23 400 μg/kg. Gymnodimine‐containing shellfish occurred at 37 of the 63 sites sampled from around New Zealand. This study demonstrates that accumulation of gymnodimine is not limited to T. chilensis and can occur in other shellfish species over much of New Zealand. Gymnodimine is a possible cause of the numerous historical biotoxin screen‐positive results.     

麻痹性贝毒在毛蚶体内的转化过程研究

麻痹性贝毒能够在贝类体内累积,威胁海产品消费者健康。在以往调查中,多次在毛蚶(Scapharca subcrenata)体内发现高含量的麻痹性贝毒,但对于毛蚶体内麻痹性贝毒的转化过程及其食品安全风险还缺乏认识。通过室内模拟实验,选择太平洋亚历山大藻(Alexandrium pacificum)和链状裸甲藻(Gymnodinium catenatum)作为产毒藻种,研究了两种有毒藻种所产麻痹性贝毒在毛蚶体内的转化过程。结果表明,毛蚶体内主要出现了三种麻痹性贝毒转化过程,一是R1位羟基的还原反应,二是N-磺酰氨甲酰基类毒素R4位磺酸基团的水解反应,三是含羟基苯甲酸(hydroxybenzoate)基团的链状裸甲藻毒素在R4位的水解反应。毛蚶体内麻痹性贝毒的生物转化过程复杂,对毛蚶毒性的影响具有一定的不确定性,未来仍需要进一步深化毛蚶体内毒素累积、代谢、转化过程的研究,同时加强对毛蚶体内毒素含量的全面监测,防范毛蚶可能导致的麻痹性贝毒中毒风险。     

Population biology of Excirolana armata (Dana, 1853) (Isopoda,Cirolanidae) on an exposed sandy beach in Southeastern Brazil

The reproductive biology and population dynamics of the cirolanid isopod Excirolana armata (Dana, 1853) were analysed through monthly samples from December 2003 to November 2005 on Una beach, São Paulo state (24° S), in Southeastern Brazil. Sampling was performed along three transects established from the base of foredunes to the waterline. On Una beach, E. armata showed continuous reproduction with higher abundances of ovigerous females in winter and spring (July–November) with a higher peak of juveniles in spring (November 2004). The fecundity ranged from 2 to 18 eggs/embryos per female, depending on the female length. The incubation period was estimated as 2 months. The life span of males and females was nearly 1 year. The short life span and the high energetic expenditure inherent to reproduction with maternal care, probably kept females from producing more than one brood in their lifetime. When comparing the population of E. armata on Una beach (24° S) with populations in Southern Brazil (32° S), Uruguay (34° S) and Argentina (36° S), it was verified that several biological population traits (length of the smallest juvenile, length of the largest individual, length of the smallest and largest ovigerous females, range of fecundity and life span) tended to increase at higher latitudes, whereas other traits (instantaneous rate of mortality and the curvature parameter of von Bertalanffy growth function) tended to decrease. However, comparing E. armata on Una beach (24° S) with a population situated at a close latitude (25° S), unexpected differences in relation to population structure and to growth demonstrated and reinforced the importance of density‐dependent factors over life history traits of E. armata on dissipative beaches.     

A new approximation for ocean waves propagating over a beach with variable depth

In this paper, the phenomenon of ocean waves propagating over a beach with variable water depth is re-examined. Based on the assumption of shallow water, a linearised shallow water equation is solved with an arbitrary beach profile. These irregular beach profiles form a set of partial differential equation with variable coefficient as the governing equation, which is the main obstacle in obtaining analytical solutions. In this paper, two families of beach profile are used as examples. A parametric study is conducted to investigate the influence of the beach profiles on the water surface elevation (η) and velocities (u).     

The recreational use of beaches and consequences for the development of new trends in management: the case of the beaches of the Metropolitan Region of Barcelona (Catalonia, Spain)

This article offers some reflections on beach management, on the basis of the results of a survey on the recreational use of beaches and beach users' perception, which was carried out in the Metropolitan Region of Barcelona in 1992. The first part outlines the situation of the beaches, recent metropolitan beach policy and the organization of administrative bodies responsible for beach management. Survey objectives and methods are also explained briefly. In the second part, the principal results of the survey are presented and different beaches are compared in an attempt to analyse the types of users, the uses they make and the perception they have of the beaches. The conclusions identify new emerging social needs which demonstrate that new trends in beach management are also needed. Practical recommendations, related to this emerging perception of beaches as natural systems, are suggested.     

渤海湾南部滩涂贝类群落结构特征及其环境因子相关性研究

本研究以渤海湾南部(滨州)滩涂为研究区域,设置6个断面共36个采样站位,覆盖潮间带(高潮带-中潮带-低潮带)和潮下带,研究该区域贝类资源群落结构特征及其环境因子相关性。结果表明:整个调查区域常见贝类总共有30种。潮间带共有23种常见贝类,优势种为光滑篮蛤(Potamocorbula laevis Hinds 1843)、四角蛤蜊(Mactra quadrangularis Reeve 1854)、短文蛤(Meretrix petechialis Lamarck 1799);潮下带共有26种常见贝类,优势种为中国蛤蜊(Mactra chinensisi Philippi 1846)、等边浅蛤(Gomphina aequilatera Sowerby 1825)、朝鲜笋螺(Terebra koreana Yoo 1976)、红带织纹螺(Nassarius succinctus A.Adams 1852)、纵肋织纹螺(Nassarius variciferus A.Adams 1851);潮间带贝类多样性指数(H'')和均匀度指数(J'')显著高于潮下带,而丰富度指数(D)则相反;潮间带贝类生物量(710.16 g/m²)和栖息密度(4 523个/m²)远高于潮下带(17.10 g/m²,35个/m²)。群落结构多元统计分析将贝类按照站位划分为5个组群,包括东侧潮下带、西侧潮下带、西侧潮间带、东侧潮间带以及D4站位。冗余分析(RDA)结果表明,对潮间带贝类影响较大的环境因子主要为沉积物的粒径以及砂、粉砂含量,而对潮下带贝类影响较大的主要为浮游植物密度、沉积物的粒径以及砂、粉砂和黏土含量。渤海湾南部(滨州)滩涂贝类资源较为丰富,但应从不同滩涂区域生态特性的角度出发,加强贝类的保护和资源修复,本研究可为该区域贝类的资源养护和可持续利用提供数据基础。     

浙江沿岸海域螺贝类群落结构及其季节变化

根据2019年全年4个航次浙江沿岸海域单船底拖网调查资料,分析了浙江沿岸海域螺贝类的种类组成、优势种及资源密度分布的季节变化,采用生态多样性指数和丰度/生物量比较曲线(ABC曲线)分析了群落物种多样性及其动态变化。结果表明:浙江沿岸海域全年共捕获螺贝类43种,隶属于2纲, 7目, 26科。螺贝类群落优势种为棒锥螺(Turritella bacillum)、习见蛙螺(Bursa rana)和褐管蛾螺(Siphonalia spadicea),其中棒锥螺为浙江沿岸螺贝类群落中的绝对优势种。浙江沿岸海域螺贝类年平均资源密度为212.06kg/km²,其中夏季平均资源密度为全年最高,资源密度总体上呈现由北向南逐渐增高的趋势。种类丰富度指数(D)、物种多样性指数(H’)和种类均匀度指数(J′)三种群落多样性指数均不高,螺贝类群落多样性处于较低水平;根据ABC曲线评估干扰对螺贝类群落的影响可得:全年4个季节浙江沿岸螺贝类群落均处于中等干扰状态。     

天津潮间带经济贝类资源变化规律研究

为研究天津潮间带经济贝类资源的变化特征,指导当地贝类资源的修复及合理开发,2008年—2020年,作者对汉沽鲤鱼门、大港减河口及大港滨海湿地三段潮间带滩涂开展持续的经济贝类资源调查.结果表明:共发现经济贝类24种,每段滩涂每年7～14种;各滩涂的经济贝类生物量范围为223.5～1665.5 g/m2,鲤鱼门及减河口滩涂...     

Community and Population Responses of the Macroinfauna to Physical Factors over a Range of Exposed Sandy Beaches in South-central Chile

Ten exposed sandy sites covering a range from reflective to dissipative beaches were sampled in south-central Chile to evaluate: (1) spatial changes in species richness, abundance and biomass of the intertidal macroinfauna in response to changes in mean grain size, beach face slope and beach type, and (2) spatial changes in abundance, biomass and body sizes of the most abundant species in response to changes in the physical factors. The number of species, abundance and biomass per beach in general decreased with increasing particle size and beach face slope (steeper beaches) and increased from reflective to dissipative conditions. The best fit for number of species was with Dean's parameter, a measure of beach type, whereas for abundance and biomass the best fits were found with particle size. The isopod Excirolana braziliensis and the anomuran Emerita analoga increased in abundance and biomass towards dissipative conditions, whereas Excirolana hirsuticauda showed the opposite trend in biomass and was significantly larger in beaches with steeper profiles. It is concluded that responses to changes in beach type are more pronounced at community level than within species populations.