渤海中部COD的时空分布特征及其对富营养化的贡献分析

以2013年春、夏、秋、冬4个季节对渤海中部海区的调查数据为依据,对调查海域表、中、底层水体的化学耗氧量(Chemical oxygen demand, COD)的时空分布、来源及其对富营养化的贡献等进行了分析。结果显示,调查海域COD平均含量以夏季最高,秋季次之,春季最低。垂直分布差异表现为春季表层最高,中层最低;夏季表层最高,底层最低;秋季和冬季均为中层最高,底层最低。各站位 COD 平均浓度水平分布在春季无明显的高值出现,含量分布较均匀,夏季 COD从西向东呈降低趋势,高值主要分布于西部海域;秋季和冬季COD从北向南呈递减趋势,高值分布于调查海域北部。调查海域各站位营养指数E值变化范围为0.088–2.995,平均值为0.337±0.403,大于1的站位有25个,其中,秋季20个,冬季5个,表明大部分调查海域水质未达到富营养化状态,处于较低营养水平。COD 对调查海域富营养化的贡献率为46.15%–141.41%,平均值为(71.36±14.98)%,表明COD在渤海海区富营养化中占据了主要地位。     

长江口及其邻近海域渔业资源结构的季节变化

基于2012年8月(夏季)和11月(秋季)、2013年1月(冬季)和5月(春季)长江口及其邻近海域的渔业底拖网调查数据,对渔业种类组成、数量分布、群落多样性及其与环境因子的关系进行了研究。结果显示,共捕获渔业种类114种,隶属于17目66科90属,其中鱼类12目36科50属58种,鲈形目种类最多(26种),甲壳类2目25科33属49种,头足类仅3目5科6属7种。长江口及其邻近海域渔业资源优势种季节更替明显,仅龙头鱼(Harpodon nehereus)为全年优势种。秋季平均单位网次渔获量最高(29.20 kg/h·net),春季(17.95 kg/h·net)高于夏季(14.60 kg/h·net),冬季最低(10.15 kg/h·net),各季节均以底层鱼类和甲壳类为主,中上层鱼类渔获量仅春季较高,占总渔获量20.1%。春、夏季群落多样性指数较秋、冬季高,春季(163)和夏季(176)渔业资源群落更替指数较高,群落稳定性较低,夏季(6)和冬季(–5)迁移指数接近于零,渔业生物迁入和迁出处于相对平衡状态。各季节渔获种类数和总渔获量分别与底层鱼类和甲壳类渔获量呈极显著正相关;秋季渔获种类数与表层温度呈显著正相关,与深度呈极显著正相关。长江口及其邻近海域渔业低质种类呈增加趋势,并且渔业资源结构存在明显的季节变化,渔获种类数、总渔获量及群落多样性指数与表层温度及深度关系密切。     

汕头南澳-东山海域初级生产力的时空特征

根据2014年9月(秋季)、12月(冬季)、2015年4月(春季)、2016年7月(夏季)在南澳岛与东山岛之间的近海海域进行的生态环境调查,分析了该海域叶绿素a浓度和初级生产力的时空变化特征。结果表明,叶绿素a浓度变化范围为0.37～14.9μg/L,平均值分别为:夏季(8.2μg/L)秋季(4.9μg/L)冬季(1.52μg/L)春季(1.47μg/L)。表层初级生产力的波动范围为0.6～45 mg(C)/(m~3·h),平均值分别为:秋季20.3 mg(C)/(m~3·h)夏季18.2 mg(C)/(m~3·h)春季14.4 mg(C)/(m~3·h)冬季5.6 mg(C)/(m~3·h)。水柱初级生产力变动范围为14.1～3066.6 mg(C)/(m~2·d),平均值分别为:秋季1034.2 mg(C)/(m~2·d)夏季715.5 mg(C)/(m~2·d)春季453.4 mg(C)/(m~2·d)冬季133.8 mg(C)/(m~2·d)。除夏季外,整个调查海域的叶绿素a浓度空间变化规律基本为由西北向东南方向递减;夏季调查海域表层叶绿素a的浓度都较高,在南澳岛的南面出现一个叶绿素a的低值区。该海域初级生产力的空间分布规律性较差。叶绿素a和初级生产力与营养盐浓度在春季均呈显著正相关,但在其他季节相关性不强。氮营养盐在春季和秋季可能是南澳-东山海域浮游植物生长的潜在限制因子。为获得较好的渔业增养殖效益,应该根据初级生产力现状对该海域的养殖品种和规模进行合理规划。     

獐子岛养殖水域叶绿素含量时空分布特征及初级生产力季节变化

2005年3、5、7和10月对獐子岛养殖海域(共设18个站住)进行叶绿素浓度的调查.结果表明,调查海区叶绿素浓度为1.23～2.85 mg/m3,均值为1.78士0.57 mg/m3.叶绿素浓度的季节性变化显著,最高值出现在冬季,夏季的值最低;平面分布的特性为春、夏、冬季分布比较均匀.秋季叶绿素浓度的区域性差异较大,主要表现为近岸区的叶绿素浓度低于中间深水区域,可能与养殖虾夷扇贝摄食压力有关.但尚需进一步研究.垂直分布较为均匀,夏季表层叶绿素浓度高于底层,其他季节的分布趋势与夏季相反.初级生产力的季节性变化明显,与叶绿素的变化趋势不同,从3～10月,初级生产力逐渐增大,变化范围为30.4～117.0 mgC/m2·d,平均值为76.6±41.9 mg C/m2·d.结合同步调查的水温、营养盐数据得知,水温和溶解性无机氮是影响初级生产力的主要因素.     

近年渤海中部海域活性磷酸盐的时空变化特征

渤海封闭性强,水动力条件和自净能力较弱,其生态系统较为敏感和脆弱。2011年位于渤海中部的蓬莱19-3油田发生重大溢油事故,对渔业生态环境和渔业资源造成了严重影响。为了解和掌握该起溢油污染事故发生后渔业生态环境的变化状况,分别于2012?2014年在渤海中部海域进行了9个航次的生态环境跟踪调查。利用其中部分调查资料,作者对渤海中部活性磷酸盐的时空变化特征及其影响因素进行了分析探讨。结果显示,(1)2012?2014年春季和夏季渤海中部海域活性磷酸盐含量符合第二类海水水质标准要求,秋、冬季部分海域已受到活性磷酸盐的污染。(2)不同季节渤海中部海域活性磷酸盐的平面分布趋势各异,垂直分布也存在季节差异。春季和夏季活性磷酸盐呈现由表层至底层递减的趋势,秋季和冬季接近呈垂直分布均匀状态。(3)渤海中部海域活性磷酸盐平均含量季节变化明显,其含量顺序由高到低依次为冬季、秋季、春季、夏季,冬季明显高于夏季。2014年渤海中部海域活性磷酸盐含量低于2013年,呈逐年降低趋势。(4)渤海中部海域活性磷酸盐时空变化受到诸多因素的影响,营养盐的外源补充、内源再生和生物消耗是影响活性磷酸盐时空变化的最重要因素。     

洱海水体光学特性的季节变化及其影响因素分析

为了探究人类活动对洱海水体富营养化进程的影响,2014年4月、7月、11月和2015年1月在洱海全湖设置36个采样点进行采样监测,研究洱海光学衰减系数(K)、透明度(SD)、浊度(Turb)和叶绿素a(Chl-a)的季节变化规律及其相关性,并分析沉水植物分布对光学特性的影响,以期为洱海富营养化治理和控制提供基本数据支持。结果表明,光学衰减系数的季节变化规律为春季(0.59 m-1)冬季(0.68 m-1)秋季(0.95 m-1)夏季(1.05 m-1);叶绿素a含量与光学衰减系数的季节变化规律相同,为春季(5.24μg/L)冬季(5.49μg/L)秋季(12.33μg/L)夏季(14.22μg/L);透明度季节变化规律为夏季(1.86 m)秋季(2.28 m)春季(3.00 m)冬季(3.07 m);浊度季节变化规律是春季(32.50 mg/L)冬季(32.52 mg/L)秋季(32.64 mg/L)夏季(32.70 mg/L)。光学衰减系数与透明度、浊度和叶绿素a均呈显著正相关(P0.01),相关系数分别为0.648、0.523和0.467;透明度与叶绿素a和浊度均呈显著负相关(P0.01),相关系数分别为0.497和0.564;浊度与叶绿素a显著正相关(P0.01),相关系数为0.241。叶绿素a在一定程度上会影响光学衰减系数,但不是其主要影响因素。在秋季和冬季,沉水植物区的水体光学衰减系数显著低于无沉水植物区(P0.05),但这种差异在春季和夏季不显著(P0.05)。在一年中的各季节,沉水植物区与无沉水植物区的水体透明度和叶绿素a含量均无显著差异(P0.05);沉水植物区的水体浊度显著低于无沉水植物区(P0.01)。     

福建平潭岛海域游泳生物生态和资源保护

1990年4个季节月调查，平潭岛海域有游泳生物88种，其中鱼类62种，甲壳类22种，头足类4种。鱼类区系属于印度－西太平洋的中国－日本亚区。种类数的季节分布呈秋季＞夏季＝冬季＞春季，生物量匠优势种均为龙头鱼和带鱼，生物量的季节分布呈冬季＞秋季＞夏季＞春季，密度呈夏季＞春季＞冬季＞秋季。平均月生物量和密度岛北部海域分别是岛南部海域的2.55倍和1.32倍。本文分析了种类组成与环境的关系，并提出了渔业资源保护的建议：（1）保护幼鱼的索饵场和生殖群体的产卵场；（2）适当适长伏季休渔期；（3）定置网的最适捕捞力量估算为12912张。     

2008年闽江口海域叶绿素a时空分布及其与环境因子的相关性分析

2008年3月-12月对闽江口海域进行了每月1次共10航次的调查,分析了该海域叶绿素a的时空分布特征,以及与环境因子的相关性.结果表明:闽江口海域叶绿素a浓度范围为0.25 ～45.38μg/L,平均值为3.93 μg/L.叶绿素a浓度的平面分布在春季和夏季总体呈琅岐岛附近海域＞川石岛以东海域＞定海湾的趋势,秋季和冬季平面分布较均匀.叶绿素a浓度的季节变化总体呈现为夏季＞秋季＞春季＞冬季的特征.相关性分析显示,叶绿素a与水温呈极显著正相关,与盐度、活性磷酸盐呈显著负相关.     

渤海中部海域水体中Hg、As的时空分布特征

本研究分析了2013年5月(春季)、7月(夏季)、11月(秋季)、12月(冬季)渤海中部海域表、中、底层海水中汞(Hg)、砷(As)两种元素的时空分布特征。结果显示,Hg 的含量范围为0.0029–0.3926μg/L,平均含量为0.0676μg/L。从垂直分布来看,水体中Hg的含量呈现底层>中层>表层的变化特点;从四季的变化特点看,水体中Hg的含量呈现春季>冬季>秋季>夏季的变化规律,其中,仅有夏季表层水体达到国家海水水质标准(GB3097–1997),其余水体中 Hg 的含量均有超标现象发生。As的含量范围为0.65–10.83μg/L,平均含量为1.50μg/L,除夏季表层水体中的As含量较高外,水体中的As均呈现均匀的分布模式。从垂直分布来看,As在四季的平均含量均表现为表层>中层>底层,且均未超出国家海水水质标准。研究表明,渤海中部海域水体中,As 的含量均达到Ⅰ类水质标准(20μg/L),而Hg含量却频频超出Ⅰ类水质标准(0.05μg/L)或Ⅱ类水质标准(0.20μg/L)。渤海中部海域水质已经受到了重金属的污染,推测该现象主要源于人类活动的影响。     

南澳岛海域渔业资源声学评估与空间分布

基于2014年秋季和2015年春季南澳岛海域渔业资源声学与底拖网调查数据,对该海域主要渔获物种类、资源动态与空间分布进行了评估分析。结果表明优势种类存在较大差异,短尾大眼鲷(Priacanthus macracanthus)和鹿斑鲾(Secutor ruconius)分别为秋季和春季主要优势鱼类。秋季和春季声学评估种类平均数量和生物量密度分别为(26 806±39 968)尾·n mile–2和(403.68±601.9)kg·n mile–2、(34 416±38 497)尾·n mile–2和(124.5±139.26)kg·n mile–2。统计分析结果显示,2014年秋季渔获组成单一和混合2种不同条件下,调查海域渔业资源数量与生物量密度均存在显著性差异(P=0.0070.05;P=0.0040.05);而2015年春季不同条件下差异均不显著(P=0.1130.05;P=0.3100.05)。该差异可能与不同季节声学评估种类优势集中程度相关。由于鹿斑鲾(Secutor ruconius)等种类季节性集群活动的影响,调查海域渔业资源在水平空间上分布极不均匀。此外,以15m水深为界,不同季节回波单体目标强度(TS)频率组成及其在垂直方向上的分布存在明显差异。     

对虾池塘网箱养殖罗非鱼期间水体悬浮颗粒物的动态及对罗非鱼生长和存活的影响

于2010年8-10月在广东省茂名市电白县鸡打港实验探讨了对虾-罗非鱼网箱混养池塘养殖期间水体中悬浮颗粒物(TPM)、颗粒有机物(POM)的动态变化及POM含量对罗非鱼生长和存活的影响。结果表明:(1)各池塘总颗粒悬浮物量(TPM)为(83.1±34.1)mg/L,变动于35.0~153.8 mg/L之间;颗粒无机物(PIM)含量为(34.3±11.8)mg/L,变化于19.0~54.0 mg/L之间,占总颗粒悬浮物的41.28%;浮游生物干重(PZ)波动在2.43~22.477 mg/L之间,平均值为(9.631±5.911)mg/L,其中浮游植物干重(DWP)为(8.987±5.983)mg/L,变动于2.298~22.105 mg/L之间,浮游动物干重(DWZ)为(0.645±0.607)mg/L,变动于0.018~2.724 mg/L之间;颗粒腐质与细菌量为(38.966±25.530)mg/L,变动于14.339~97.958 mg/L之间,占悬浮颗粒有机物的比例为81.77%。(2)407池网箱养殖吉丽罗非鱼的增重率和特定生长率均显著高于406、408池(P<0.05)。3口池塘罗非鱼的存活率没有显著性差异。本研究旨在为对虾-罗非鱼池塘网箱混养模式的优化提供科学依据。     

Sedimentation and sediment characteristics in sea cucumber Apostichopus japonicus (Selenka) culture ponds

Annual sedimentation, re-suspension rates and contents of particulate organic carbon (POC), particulate organic nitrogen (PON) and total phosphorus (TP) in the sediment were investigated in two sea cucumber culture ponds at Rongcheng, Shandong Province, China. The results showed that the average flux of total particulate matter in the ponds was 22.1 g m² d⁻¹. The average re-suspension rate of the sediment in the ponds was 81.7%. The re-suspension rates in spring and autumn were higher than those in summer and winter. The mean contents of POC, PON and TP in the sediment of the ponds were 4.4, 0.5 and 0.6 (mg g⁻¹), respectively, and the mean contents of Chlorophyll a (Chl a) and pheophytin in the sediment were 8.1 and 12.1 μg g⁻¹ respectively. The POC, PON and TP contents in the sediment of the ponds increased during the period of sea cucumber aestivation (summer) and hibernation (winter), while they decreased during the feeding periods. The organic matter accumulation rate and the contents of POC, PON, TP, Chl a and pheophytin in the sediment were even lower than those in the pond without sea cucumber (P<0.05). The results demonstrated that sea cucumber culture can effectively stop nutrient accumulation at the bottom of the cucumber culture ponds.     

Utilization of terrestrial organic matter by the bivalve <Emphasis Type="Italic">Corbicula japonica</Emphasis> estimated from stable isotope analysis

ABSTRACT:   Carbon and nitrogen isotopic ratios in tissue of the bivalve corbicula ( Corbicula japonica ) and particulate organic matter (POM) were measured along a salinity gradient in the Kushida Estuary, Japan. The bivalve exhibited a gradual isotopic enrichment from the uppermost estuarine site (δ¹³C = −24.8‰ and δ¹⁵N = 8.6‰) to the marine site (δ¹³C = −16.1‰ and δ¹⁵N = 11.8‰). Using the concentration-weighted mixing model, the bivalves' food source is estimated from the isotope values for the bivalves and POM from terrestrial plants, marine phytoplankton and benthic microalgae. The results indicated that the contributions of benthic micro algae and phytoplankton were small, while terrestrial particulate matter is significantly important for the corbicula diet, although the contribution varies among sampling sites.     

Growth and survival of the scallop Lyropecten (=Nodipecten) nodosus (L. 1758) in suspended culture in the Cariaco Gulf (Venezuela) during a non-upwelling period

Growth and survival of the scallop Lyropecten nodosus were studied in 1997 at two sites (inner and outer Turpialito Bay) during a non‐upwelling period normally occurring between August and November. Individuals had an initial shell height of 4.86 cm (SD=1.64 cm). Both experimental groups were held in suspended plastic baskets at the same depth (4 m). Measurements of shell height and dry weights of shell, gonad, digestive gland, remaining tissues and shell biofouling were taken at monthly intervals. Environmental parameters, including temperature, phytoplanktonic biomass, total particulate material (TPM) and associated organic (POM) and inorganic (PIM) fractions, were recorded simultaneously. At the end of the study, significant differences in growth and survival of scallops were observed between the two experimental sites. Scallops maintained inside the bay showed a 22% greater increase in shell height (7.41±0.27 cm) than those placed outside the bay (6.37±0.41 cm). Survival of scallops inside the bay was 31% higher compared with scallops outside. The greater availability of food of phytoplanktonic origin during the first two experimental months (July and August) together with greater POM throughout the whole experimental period except September, at the inner bay site, probably explained survival and growth differences observed between the two locations. Results suggest that, during the non‐upwelling period (characterized by low primary productivity and high water temperatures), POM of sedimentary origin may play an important role as an energy source required for metabolic and reproductive activities of L. nodosus.     

沉积再悬浮颗粒物对3种滤食性贝类摄食生理的影响

采用室内模拟实验法研究了不同浓度的沉积再悬浮颗粒物对3种经济贝类的滤水率、摄食率和吸收效率影响。结果表明,(1)沉积再悬浮颗粒物对3种滤食性贝类的滤水率、摄食率和吸收效率有明显的影响(P<0.05)。(2)在一定浓度范围内,3种贝类的滤水率和摄食率随沉积再悬浮颗粒物浓度的增大而增大,当再悬浮颗粒物浓度超过一定浓度后,滤水率和摄食率迅速下降。(3)实验期间(24h),随时间的变化,总悬浮颗粒物浓度为20～100mg/L时,3种滤食性贝类的滤水率呈现周期性的升降变化,总悬浮颗粒物对不同时间段3种贝类的滤水率的影响显著(P<0.05)。300和500mg/L时,总悬浮颗粒物对不同时间段栉孔扇贝和紫贻贝滤水率的影响不明显(P>0.05),而对菲律宾蛤仔滤水率的影响显著(P<0.05);在6～24h时间段,3种贝类的滤水值多次出现负值。(4)吸收效率随沉积再悬浮颗粒物浓度的增大而减小,与悬浮颗粒物有机质的百分含量的变化趋势相一致。本研究表明,沉积再悬浮颗粒物对3种滤食性贝类的摄食生理有显著的影响。     

夏季和冬季辽东湾海域水体中叶绿素a含量分布特征

为研究辽东湾海域水体中叶绿素a含量的分布特征,于2013年8月(夏季)和12月(冬季)在辽东湾设置38个站位,分别采集了表、中、底层的海水样品,检测夏季和冬季两个航次水体中叶绿素a的含量,分析该海域叶绿素a的季节分布与空间变化特征。同时利用相关性统计分析的方法,将各水质因子对叶绿素a含量影响的差异显著性进行了分析。结果显示,调查海域夏季的叶绿素a平均质量浓度为6.90μg/L,冬季为1.26μg/L,时间分布上夏季质量浓度明显高于冬季;空间水平分布上,夏季辽东湾湾口的平均叶绿素a质量浓度明显高于湾内的平均质量浓度,而冬季则越靠近湾口处叶绿素a的平均质量浓度越低,与夏季规律正好相反;空间垂直分布上,夏季表层叶绿素a的质量浓度最高,10m层次之,底层的质量浓度最低;而冬季的叶绿素a质量浓度则呈现10m层最高,底层次之,表层质量浓度最低的趋势。说明辽东湾叶绿素a含量存在明显的时间和空间分布特征;结合同期的温度、盐度、溶解氧等环境因子的调查结果,统计分析结果表明调查海域中环境因子温度、盐度、溶解氧和营养盐的季节性变化是导致叶绿素a含量趋势变化的最可能原因之一。     

The influence of body size, habitat and diet concentration on feeding of Laternula marilina Reeve

A Chinese duckbilled marine clam (Laternula marilina Reeve) was cultured in a simulated natural culture system for the preliminary determination of its physiological energetics. The results showed that both clearance rate (CR) and ingestion rate (IR) were related exponentially to body size (flesh dry weight, W) as described by the equations CR=0.49W^0.65, IR=0.96W^0.57. Body size had no effect on assimilation efficiency (AE) at water temperatures of 10°C, 16°C and 23°C, but within this range AE significantly increased with increasing water temperature. It was found that L. marilina performed in feeding behaviour far better when natural substrates conditions were provided. On a sand or silt substrate both CR and IR were two times higher than on an uncovered tank bottom. AE was also improved when sand (13.12% increase) or silt (14.19% increase) was provided. It is evident in our results that within the range of diet (as particulate organic matter, POM) concentration of 2.30±0.21 to 6.20±0.13 mg POM L^?1 the relationships between POM and CR and IR were exponential and as described by the equations CR=0.29 [POM]^0.75, IR=0.33 [POM]^1.34. In these experiments, the diet concentration threshold of pseudofaecal excretion was found to be 3.05 mg POM L^?1. There was no marked influence of diet concentration on AE, which was consistently about 60%.     

The significance of various environmental parameters for growth of the Iceland scallop, Chlamys islandica (Pectinidae), in hanging culture

Iceland scallops, Chlamys islandica (O.F. Müller), were grown in hanging culture at 3 different depths (2, 12 and 40 m below the sea surface) in a northern Norwegian fjord. The growth of the soft parts of the body and the shell increment were monitored throughout the growing season (March until September). At the same time, temperature, salinity, water density, current speed, chlorophyll, particulate organic matter (POM) and particulate inorganic matter (PIM) were monitored at each of the experimental depths. Analysis of the environmental data together with the growth data showed that growth differences between the experimental depths were essentially the results of differences in nutritional conditions for the scallops, defined by the relationship between PIM and POM in the water column. The results also showed that growth in Iceland scallops can be increased significantly by suspending the animals in a more favourable nutritional environment than that found on the natural scallop beds.