海水贝类苗种循环水培育水处理技术的研究与应用

封闭循环水育苗作为一种高技术育苗模式,其核心是养殖废水的净化处理。对于循环水系统的每一道处理工序,都有大量可选择的工艺。本试验利用自建的100 m3的海湾扇贝苗种封闭循环水培育系统,通过用各个阶段的出水养殖扇贝幼体,以及测定出水指标等来判断水处理系统的处理效果。结果表明,封闭循环水处理系统的效果是成功的。     

海州湾海域一次赤潮异弯藻赤潮与环境因子的关系

通过对2008年5月发生在连云港海州湾海域的一次赤潮异弯藻赤潮的跟踪监测,并研究其赤潮发生与环境因子的关系,得出:良好的水文气象条件,丰富的营养盐为赤潮的爆发及维持提供了基础。赤潮的发生,导致pH值、盐度、溶解氧、叶绿素a、营养盐等环境因子都发生了变化。此次赤潮异弯藻赤潮主要吸收硝酸盐和铵盐,磷酸盐是其生长的限制因子。高氮磷比也是赤潮异弯藻生长的重要调控因子。     

单胺类及5-羟色胺拮抗剂对海湾扇贝幼虫生长的影响

单胺类药物左旋多巴胺和5-羟色胺一方面可能促进海湾扇贝幼虫纤毛活动从而促进幼虫摄食,另一方面引起纤毛运动强度的改变,又影响幼虫的能量消耗,因此对扇贝幼虫的生长可能存在着双重影响。以海湾扇贝幼虫为研究对象,探讨了左旋多巴胺和5-羟色胺及5-羟色胺的两种拮抗剂曲唑酮和赛庚啶对其生长的影响及其可能的作用机制。试验结果表明,0.1ng/L左旋多巴胺和1.0ng/L 5-羟色胺对海湾扇贝幼体的生长率促进作用最强,而5-羟色胺的促生长作用可被曲唑酮和赛庚啶抑制,说明5-羟色胺可能是通过5-HT1或5-HT2型受体起作用的。在海湾扇贝的育苗实践中可以选择使用低质量浓度的5-羟色胺以促进幼虫的生长。     

黄河入海泥沙年际通量对莱州湾渔业资源结构的影响

根据2009年8月-2013年8月莱州湾海域渔业拖网调查数据,分析该海域渔业种群组成、优势种、空间分布和资源量的年际变动,以了解黄河入海泥沙通量对莱州湾渔业结构的影响.结果表明:(1)莱州湾渔业资源量整体呈下降趋势,主要以鱼类为主,甲壳类次之,头足类最少;鱼类中以中上层鱼类为主,网获量明显多于底层鱼类,但2011年8月底层鱼类稍多于中上层鱼类;(2)莱州湾渔业资源各年份的优势种有所变动,中上层鱼类和底层鱼类的优势种变动较大,甲壳类优势种变动较少,鱼类优势种组成存在年际更替现象,主要由经济价值高、个体大的种类向经济价值低、个体小的种类演替.主要优势种集中于斑鲦、矛尾鰕虎鱼、口虾蛄、小带鱼和日本枪乌贼等种类.2010年斑鲦大量暴发,为唯一优势种;(3)2009-2013年黄河入海泥沙年际通量与鱼类种数、底层鱼类数和渔业资源数存在显著相关性,与底层鱼类生物量存在极显著相关性.综上所述,黄河入海泥沙年际通量的变动对莱州湾渔业资源量和资源结构都产生了一定影响.     

海湾扇贝性腺发育的生物学零度

性腺发育的生物学零度是生物的繁殖习性和生物积温研究中的一个重要指标。正如菊地省吾提出皱纹盘鲍性腺发育的生物学零度以后,人们已可以通过控制积温的方法有效地预报和控制鲍鱼的产卵。因此研究海湾扇贝性腺发育的生物学零度,在海湾扇贝的繁殖理论研究以及海湾扇贝的工厂化人     

象山港大型底栖动物的生物多样性和次级生产力研究

2001年8月和2001年12月对象山港8个站进行了大型底栖动物两个航次的调查取样。发现4大类底栖动物43种,其中多毛类12种(占28%)、软体动物16种(占37%)、甲壳动物6种(占14%)、棘皮动物5种(占12%)。优势种为不倒翁虫(Sternaspis scutata Ranzani)、西格织纹螺(Nassarius siquijorensis A.Adams)和滩栖阳遂足(Amphiura vadicola Matsumoto)。研究海域底栖生物多样性指数偏低、均匀度小、群落结构不稳定。象山港陆源排污量逐年增大、海水养殖规模扩大、养殖密度增加是导致生物多样性降低的可能原因。整个象山港年平均次级生产力P为4.32 g(AFDW)/(m2?a);港口最低,为0.99 g(AFDW)/(m2?a);港底最高,为7.02 g(AFDW)/(m2?a);象山港中部介于港口和港底之间。象山港大型底栖动物年平均P/B为2。     

黑龙江勤得利湾水质理化特征

20 0 3年 5月、 7月、9月和 1 2月对黑龙江勤得利湾水化学特征进行了调查 ,结果表明 :勤得利湾水质良好 ,透明度变幅在 2 5～ 45cm ,pH值变幅在 7 1 4～ 7 5 2 ,水呈中性。水型属重碳酸盐类 ,钙组Ⅰ型 (CcaⅠ)软水。水中主要营养元素含量 ,总氮含量较高平均为 1 0 30mg/L ,磷酸盐含量较低平均为 0 0 1 7mg/L。离子含量以冬季最高 85 5 2mg/L ,春季最低 48 1 1mg/L。水中离子含量高低次序为HCO-3 >Ca2 +>Cl- >Na+s+K+>Mg2 +。探讨了水体的营养类型和利用。     

Tube-net farming and device for efficient tissue segregation for industrially important agarophyte Gracilaria edulis (Rhodophyta)

According to the Food and Agricultural Organisation of United Nations seaweeds are being increasingly farmed rather than gathered. It is evident that, seaweed mariculture holds considerable promise for diversifying the livelihood of low-income, artisanal fishermen. Nevertheless, increased labour constraints have been realised as a bottleneck for the sustainability of farming in developing countries, where spending on infrastructure cost is meager. We herein report a tube-net farming for industrially important red alga Gracilaria edulis and also a new design for a harvester. The average biomass yield reported for the tube-net method over a 45 day growth cycle was 11.93 ± 2.55 kg fr wt raft⁻¹; while the average daily growth rate was 3.40 ± 0.57% day⁻¹. Harvesting is a critical step which determines the quality of a product. However, traditional methods do not allow segregation of product-rich (SAP and hydrocolloid) older thallus, from the growing apical tips. A two stage harvesting operation successfully achieved segregation of 33.87–55.56% of the clean apical biomass and 35.95–65.02% of the basal portion of the alga, leaving behind an empty tube for re-stocking. The tube-net farming method, coupled with an improved harvesting efficiency was aimed at developing appropriate management strategies for commercial farming of seaweeds.     

Strategies for enhancement of natural bay scallop, Argopecten irradians irradians, populations; A case study in the Niantic River estuary, Connecticut, USA

We investigated strategies to enhance populations of bay scallops,Argopecten irradians irradians (Lamarck, 1819), in a presumablyrecruitment-limited natural habitat. At present, the Niantic Riverestuary supports only a minor bay scallop population that is harvestedrecreationally. Three enhancement strategies were evaluated; (1)collection and redistribution of natural spatfall, (2) introduction andover-wintering of hatchery-reared stock into natural habitat to providenew spawning stock, and (3) over-wintering of hatchery-reared stock insuspension culture for creation of mobile spawner sanctuaries. Anassessment of natural bay scallop recruitment in the Niantic Riverconducted in 1997 indicated that few spat were found, they were widelydispersed within the river, and peak spawning occurred in late July1997. Direct re-seeding was evaluated as an enhancement measure byplanting hatchery-reared scallops ( 38 mm shell height) insmall-scale, 100-m² plots at different times and densities.Time of planting and the inferred predation intensity were major factorsaffecting survival; whereas, planting density had no significant effect.Approximately 9,000 scallops (35–45 mm shell height), broadcastwithin an eelgrass bed in November 1997, had high over-winter survivaland underwent gametogenesis and spawning during 1998. Of 26,000 bayscallops ( 45 mm shell height) over-wintered in suspensionculture from 1998–1999, approximately 60–80%survived, and these scallops spawned in mobile sanctuaries, during thesummer of 1999. There is good potential for using aquacultural methodsfor enhancement of bay scallop populations when natural recruitment ispoor and habitat and environmental conditions are not limiting.     

Connectivity of the bay scallop (Argopecten irradians) in Buzzards Bay,Massachusetts, U.S.A.

The harvest of bay scallops (Argopecten irradians) from Buzzards Bay, Massachusetts, U.S.A. undergoes large interannual fluctuations, varying by more than an order of magnitude in successive years. To investigate the extent to which these fluctuations may be due to yearly variations in the transport of scallop larvae from spawning areas to suitable juvenile habitat (settlement zones), a high‐resolution hydrodynamic model was used to drive an individual‐based model of scallop larval transport. Model results revealed that scallop spawning in Buzzards Bay occurs during a time when nearshore bay currents were principally directed up‐bay in response to a persistent southwesterly sea breeze. This nearshore flow results in the substantial transport of larvae from lower‐bay spawning areas to settlement zones further up‐bay. Averaged over the entire bay, the spawning‐to‐settlement zone connectivity exhibits little interannual variation. However, connectivities between individual spawning and settlement zones vary by up to an order of magnitude. The model results identified spawning areas that have the greatest probability of transporting larvae to juvenile habitat. Because managers may aim to increase scallop populations either locally or broadly, the high‐connectivity spawning areas were divided into: (i) high larval retention and relatively little larval transport to adjoining settlement areas, (ii) both significant larval retention and transport to more distant settlement areas, and (iii) little larval retention but significant transport to distant settlement areas.