Polycyclic aromatic hydrocarbon contamination and recovery characteristics in some organisms after the Nakhodka oil spill

Following the oil spill from the Russian tanker Nakhodka in 1997 in the Sea of Japan, polycyclic aromatic hydrocarbons (PAH) were monitored for three years in some molluscs from the Mikuni-cho shore in Japan. Total PAH concentrations in marine organisms except for spiny top shell, ranged from 5.3 to 32.7 ng/g wet weight, but no trends were evident. Total PAH concentration in spiny top shell (Turbo cornutus) was 44 ng/g w.w. in the first month after the oil spill. However, it rapidly decreased to less than 5.4 ng/g w.w. from the second month. Spiny top shell, which was exposed to dietary Nakhodka heavy fuel oil, concentrated benzo(a)pyrene to 17.1 ng/g w.w. after two weeks of exposure and then rapidly eliminated it during an elimination phase. These results suggest that spiny top shell accumulates PAHs because of their low ability to metabolize PAH, but it can excrete parent PAHs rapidly when removed from the source of contamination. Thus it is suitable as an indicator organism in monitoring oil contamination. It can also be inferred from these field and laboratory investigations that, in three years, organisms from the Mikuni-cho shore seem to have adequately recovered from the Nakhodka oil spill contamination.     

嵊泗列岛海域三种贻贝贝体框架特征的差异

以壳长SL、壳宽SW、壳高SH(BD)、OA(壳顶至韧带末端的直线距离)、OB(壳顶至壳背面最高点的直线距离)、OC(壳顶至壳后端最远点的直线距离)、OD(壳顶至壳高性状在腹缘的落点的直线距离)、AB(韧带末端至壳背缘最高点的直线距离)、BC(壳背缘最高点至壳后端最远点的直线距离)、CD(壳后端最远点至壳高性状在腹缘的落点的直线距离)为贝体框架变量,采用多元分析方法系统比较了嵊泗列岛海域厚壳贻贝、紫贻贝和"杂交贻贝"贝体框架特征的差异,结果表明:(1)在所涉9项贝体框架特征指标中,紫贻贝与厚壳贻贝间无显著差异的指标仅为L5(OC/SL)和L7(AB/SL)(P0.05),而"杂交贻贝"各项指标则均与厚壳贻贝和紫贻贝具显著差异(P0.05),厚壳贻贝和紫贻贝变异系数大于10%的指标均仅为L7(AB/SL),而"杂交贻贝"则仅为L3(OA/SL);(2)厚壳贻贝与紫贻贝间的欧氏距离最短(P0.05),仅为0.160;厚壳贻贝与"杂交贻贝"间和紫贻贝与"杂交贻贝"间的欧氏距离相近(P0.05),分别为0.452和0.418;(3)经主成分分析,提取到的3个特征值均大于1的主成分,累计贡献率达82.928%,其中第一主成分、第二主成分、第三主成分可依次归为与滤食功能区水平剖面占比相关的贝体框架因子,与消化功能区水平剖面占比相关的贝体框架因子,和与消化功能区垂直剖面占比相关的贝体框架因子,通过第一主成分仅能较清晰地区分厚壳贻贝和"杂交贻贝";(4)采用逐步判别法,以判别贡献率较大的L1(SW/SL)、L3(OA/SL)、L4(OB/SL)、L5(OC/SL)、L6(OD/SL)和L7(AB/SL)为自变量,所建Fisher分类函数方程组可较清晰区分厚壳贻贝、紫贻贝和"杂交贻贝",三者的判别准确率依次为94.6%、94.6%和100%,综合判别准确率为96.4%。     

贻贝粘性蛋白组成、作用机理与应用

从贻贝足丝的结构和组成特征开始,全面总结了到目前为止所发现的贻贝足丝内部和表面层的结构特点以及相关重要组成蛋白的种类和理化特性,着重讨论了在贻贝足丝粘附中起重要作用的足丝斑块部分的粘性蛋白组成、结构、分布特征以及相互作用。同时,也讨论了贻贝粘附机理以及DOPA(3,4-二羟基苯丙氨酸)在实践中的重要应用,探讨了DOPA的作用及其衍生物在粘胶剂、密封剂、涂料、生物防污等领域,特别是生物医学中的应用和前景。     

Saldanha Bay,South Africa III: new production and carrying capacity for bivalve aquaculture

Measurements of NH₄, NO₃, urea and HCO₃ uptake using 15N and 13C stable isotope tracers were undertaken in Saldanha Bay, South Africa, between January 2012 and January 2013. These studies provide the first direct measurements of N utilisation by the plankton in the bay. Primary production in the bay is driven predominantly by the advection of nutrients from the neighbouring shelf environment during upwelling events, with terrestrial and other sources providing minor inputs. New production (NO₃-based) was calculated from the f-ratio and total primary production and was used to provide estimates of potential carrying capacity for bivalve culture. Despite the apparent light limitation of NO3 uptake in the winter, the availability of NO₃ appeared to exert the major influence on new production throughout the year. In addition, new production was modulated by NH₄ availability as shown by the suppression of NO₃ uptake by concentrations higher than 1?1.5?mmol m^?3. The estimated areal new production of 0.60?g C m^?2 d^?1 yielded a bay-wide annual estimate of 9 811 t C ha^?1 y^?1, slightly higher than previous calculations based on physical models. It is estimated that the total annual production of mussels and oysters, respectively, for a 1 000-ha cultivation area is approximately 40 000–53 000 t y^?1 (mainly Mytilus galloprovincialis) and 4 600–6 000 t y^?1 (Crassotrea gigas). The combined total production figures constitute only 24–31% of the surplus new production. A combined harvestable carrying capacity of 74 000–82 000 t y^?1 can be calculated from this surplus. However, from a management and ecological perspective, bivalve culture should be limited to well below this theoretical maximum. Even with this constraint, there appears to be considerable scope for expansion of bivalve farming over the modest, present levels with little jeopardy to ecological integrity.