FerryBox and MERIS – Assessment of coastal and shelf sea ecosystems by combining in situ and remotely sensed data

An automatic measuring system called “FerryBox” was installed in the North Sea on a ferry travelling between Germany (Cuxhaven) and Great Britain (Harwich), enabling online oceanographic and biological measurements such as salinity, temperature, fluorescence, turbidity, oxygen, pH, and nutrient concentrations. Observations made along the ferry transect reveal characteristic phenomena such as high salinity inflow through the Channel into the Southern Bight, algal bloom dynamics and related oxygen and pH changes. Combination of these online observations with remote sensing enhances the spatial resolution of the transect related measurements. Several examples of the synergy between these two measuring strategies are shown, both for large-scale algal blooms in the North Sea as well as for local intense but short-term blooms in the German Bight. Coherence of the data sets can be gained and improved by using water transport models in order to obtain synoptic overviews of the remotely sensed and FerryBox related parameters. Limitations of the currently used algorithms for deriving chlorophyll-a from remote sensing images for coastal and shelf seas (Case-2 water) are discussed, as well as depth related processes which cannot be properly resolved on the basis of water intake at a fixed point. However, in unstratified coastal waters under normal conditions FerryBox data represent average conditions. The importance of future applications of this combination of methods for monitoring of coastal waters is emphasized.     

The biogeochemical effect of seaweeds upon close-to natural concentrations of dissolved iodate and iodide in seawater – Preliminary study with Laminaria digitata and Fucus serratus

Toward assessing the biogeochemical significance of seaweeds in relation to dissolved iodine in seawater, the effect of whole seaweeds (Laminaria digitata and Fucus serratus) upon iodide and iodate, at essentially natural concentrations, has been studied. The weeds were carefully removed from the sub-littoral zone of the Menai Straits and exposed to iodide and iodate at their natural temperature (6 °C), but under continuous illumination. Laminaria digitata was found to decrease the concentration of iodate with an exponential rate constant of 0.008–0.24 h⁻¹. This is a newly discovered process which, if substantiated, will require an entirely new mechanism. Generally, apparent iodide concentration increased except in a run with seawater augmented with iodide, where it first decreased. The rate constant for loss of iodide was 0.014–0.16 h⁻¹. Meanwhile, F. serratus was found not to decrease iodate concentrations, as did L. digitata. Indeed, after ∼30 h iodate concentrations increased, suggesting that the weed may take in iodide before oxidising and releasing it. If substantiated, this finding may offer a way into one of the most elusive of processes within the iodine cycle – iodide oxidation. With both seaweeds sustained long-term increases of apparent iodide concentration are most easily explained as a secretion by the weeds of organic matter which is capable of reducing the Ce(IV) reagent used in determination of total iodine. Modelling of the catalytic method used is provided to support this contention. The possibility of developing this to measure the strain that seaweeds endure in this kind of biogeochemical flux experiment is discussed. A Chemical Oxygen Demand type of approach is applied using Ce(IV) as oxidant. The results of the iodine experiments are contrasted with the several investigations of ¹³¹I interaction with seaweeds, which have routinely used discs of weed cut from the frond. It is argued that experiments conducted with stable iodine may measure a different variable to that measured in radio-iodine experiments.     

Numerical simulation of flow around a circular cylinder close to a flat seabed at high Reynolds numbers using a k–ε model

High Reynolds number flows around a circular cylinder close to a flat seabed have been computed using a two-dimensional standard high Reynolds number k–ε turbulence model. The effects of gap to diameter ratio, Reynolds number and flat seabed roughness for a given boundary layer thickness of the inlet flow upstream of the cylinder have been investigated. Hydrodynamic quantities and the resulting bedload transport have been predicted, and the vortex shedding mechanisms have been investigated. Predictions of hydrodynamic quantities around a cylinder located far away from the bed (so that the effect of the bed is negligible) are in satisfactory agreement with published experimental data and numerical results obtained for the flow around an isolated cylinder. Results for lower Reynolds number flows have also been computed for comparison with the high Reynolds number flow results. Overall it appears that the present approach is suitable for design purposes at high Reynolds numbers which are present near the seabed in the real ocean.     

Genetic structure of the common sole (Solea solea) in the Bay of Biscay: Nurseries as units of selection?

Coastal and estuarine areas in the Bay of Biscay are essential nursery habitats for sole (Solea solea). Using three intronic markers, we investigated patterns of genetic differentiation among cohorts of juveniles (0+, 1+, sub-adults) inhabiting four major nurseries in the Vilaine and Loire river estuaries, the Pertuis d'Antioche strait, and the Gironde estuary. Genetic differentiation was not significant for the age 0- and 1-groups, but was among sub-adult samples (θ_WC = 0.017; P = 0.031). Hierarchical analyses of genotypic frequencies by nested multivariate ANOVA using redundancy analysis indicated that northern nurseries of Loire and Vilaine rivers had different patterns of genotypic variation with age than southern nurseries of the Pertuis d'Antioche and Gironde estuaries (F = 1.36; P = 0.007). Bay of Biscay nurseries appeared to be spatially structured between a southern and a northern group that exhibit different genotypic distributions. Genetic drift and gene flow explains this pattern poorly, but a statistical test (P < 0.035) suggested that the metallothionein (MT) locus may be significantly impacted by selection in southern estuaries. As metallothionein is involved in heavy-metal detoxification, and southern nurseries are known to be affected by cadmium, this indicates a possible correlation between observed genotypic distributions and some nursery habitat features in sole. Some selective patterns might also be proposed to explain patterns of linkage disequilibrium observed at amylase loci in three of the four nurseries.     

Long-term evolution (1988–2008) of Zostera spp. meadows in Arcachon Bay (Bay of Biscay)

The spatial variability of seagrass meadows in Arcachon Bay, was studied between 1988 and 2008 using a combination of mapping techniques based on aerial photographs for intertidal dwarf-grass (Zostera noltii) beds and acoustic sonar for permanently submerged eelgrass (Zostera marina) populations. The results show a severe decline over the period for both species, as well as an acceleration of the decline since 2005 for Z. noltii. The total surface regression over the studied period is estimated to be 22.8 km² for Z. noltii and 2.7 km² for Z. marina, which represent declines of 33 and 74% respectively.     

A higher-order non-hydrostatic σ model for simulating non-linear refraction–diffraction of water waves

A higher-order non-hydrostatic σ model is developed to simulate non-linear refraction–diffraction of water waves. To capture non-linear (or steep) waves, a 4th-order spatial discretization is utilized to approximate the large horizontal pressure gradient. A higher-order top-layer pressure treatment is further implemented to resolve wave propagation. The model's characteristics including linear wave dispersion and non-linearity are carefully examined. The accuracy of the present model using only two vertical layers is validated by laboratory data and the available results predicted by the non-linear Schrödinger equation, Boussinesq-type equations, the non-linear mild slope equation, and the Laplace equation. Features of harmonic generation as well as the influences of dispersion and non-linearity on wave energy transfer processes are discussed.     

Field evidence of differential food utilization of phytal harpacticoids collected from Fucus serratus indicated by δC and δN stable isotopes

The present study is the first to compare trophic relationships of several co-occurring phytal harpacticoid species, in their natural habitat, using both δ¹³C and δ¹⁵N signatures. Three phytal harpacticoid species/taxa (Zaus spinatus, Tisbe spp., and Parathalestris cf. intermedia) all collected from the alga Fucus serratus, at different times of the year, were analyzed. The results indicated that the harpacticoids were utilizing food sources differently. Specific food sources of the three species/taxa could not be accurately pinpointed, but there were strong indications that F. serratus and fragments from it did contribute significantly to the diet of P. cf. intermedia and Tisbe spp. Both of these harpacticoid species overlapped in δ¹³C and δ¹⁵N values with some of the macrofaunal species, collected from the same site in Hvassahraun, Iceland, while no overlap was seen for Z. spinatus. The signatures for Z. spinatus indicated that its food sources changed seasonally.     

2011年日本Mw 9.0级地震的GPS响应研究

2011年3月11日日本宫城县以东太平洋海域发生Mw9.0级特大地震,造成了地表的严重错位并引发海啸。文中利用位于日本及周边国家的IGS站和国家海洋局GPS业务站观测数据,采用作者研制的精密单点定位(PPP)软件UniP,对此次地震的GPS数据响应进行了研究。结果表明:(1)GPS观测数据能清晰、连续地记录震时地表形变的过程,我国CHAN,NCST等站点水平方向的震时最大位移在10 cm以内,高程方向的震时最大位移在15 cm以内,且形变以可恢复性的弹性形变为主。(2)我国距震中较远,受此次日本地震的影响较小,且大部分站点是在东坐标方向出现不同程度的震后永久性位移。其中CHAN站点的震后位移最为明显,东向形变量为(1.8±0.11)cm;NCST、NLHT站点次之,东向形变量分别为(1.1±0.26)cm和(1.0±0.18)cm。(3)地震波传输到国家海洋局GPS业务站NCST、NLHT等的时间约为10 min,比海啸在深海的传播速度快约14倍,可为海啸预警提供所需的时间差。这些结果显示出GPS能够为地震监测和动力学特征研究提供有价值的基础资料,也表明中国沿海GPS业务观测系统在海底地震监测、海啸预警服务中的应用潜力。     

改性黏土对褐潮生物种Aureococcus anophagefferens的去除研究

褐潮是一种由微微型藻引发的藻华,已连续4年在渤海海域暴发,给当地带来巨大的经济损失。目前,在褐潮尚不能有效预防、预控情况下,如何控制和减少其对生态环境和沿海经济带来的危害,成为一个急需解决的问题。利用改性黏土消除藻华是一种快速有效、并得以多次现场成功应用的方法。考察比较了多种不同产地、不同类型的黏土及其改性后对褐潮生物种Aureococcus anophagef ferens(抑食金球藻)的去除效果,选取5种典型的黏土作为主要的实验材料,开展了不同条件下黏土及其改性后对A. anophagef ferens去除效率的影响研究。实验发现,因A. anophagef ferens个体微小、藻华时密度大,相同用量的黏土或改性黏土对其去除效率低于常见的硅藻、甲藻生物;不同类型黏土对其去除效率有影响,高岭土的去除效率高于蒙脱土;而黏土改性后对A. anophagef ferens的去除效率提高3倍以上。在此基础上,还考察分析了黏土粒径、分散介质等因素对A. anophagef ferens去除效率的影响,为进一步研发安全、高效的褐潮应急消除材料做了有益探索。     

Response of Nereis diversicolor population (Polychaeta,Nereididae) to the pollution impact – Authie and Seine estuaries (France)

A survey within the French National Programme of Ecotoxicology was carried out in 2002, 2003 and 2004 to study the response of Nereis diversicolor populations (Polychaeta, Nereididae) to the impact of pollution in the Authie estuary (non-contaminated site) and in the Seine estuary (contaminated site). In the period studied, the density varied from 672 ind. m⁻² to 3584 ind. m⁻² in the Authie estuary and from 80 ind. m⁻² to 920 ind. m⁻² in the Seine estuary. Biomass varied from 3.94 g m⁻² (dry weight) in February 2004 to 38.0 g m⁻² in August 2003 in the Authie estuary and from 3.4 g m⁻² in February 2002 to 0.6 g m⁻² in February 2004 in the Seine estuary. Density and biomass of the populations of N. diversicolor were consistently lower in the Seine estuary than in the Authie estuary. Size frequency histograms permit the analysis of the cohorts as well as the elaboration of the growth curves. For the individuals from the Authie estuary, the relation between dry weight (DW) and length L3 (prostomium, peristomium and chaetiger 1) was DW = 4.2205 L3^2.9832. For those from the Seine estuary, the relation between dry weight and L3 was DW = 0.4697e^1.7209L3. The individuals of N. diversicolor should belong to eight cohorts in Authie estuary (two cohorts each year) instead of six cohorts for those from the Seine estuary. These differences can be attributed to the effect of pollution on the population of N. diversicolor.     

Chromosomal index of Ostreidae

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Evaluation of nutrient components of Bangia sp.

General nutrient components including moisture, ash, crude protein, lipid and carbohydrate, inorganic elements, photosynthetic pigments, amino acids and fatty acids of Bangia sp. were analyzed and compared with Porphyra yezoensis. The results indicated that the content of protein, total amino acids and free amino acids accounted for 47.2% , 42.6% and 3.3% in dried Bangia sp. , respectively, all essential amino acids were present in relatively high levels and desirable composition. Lipid was 1.8%, in which the eicosapentaenoic acid (EPA) reached 50.5% . In per 100 g dried material, the content of chlorophyll, carotenoids, phycoerythrin and phycocyanin accounted for 766, 208, 4 600 and 2963 mg, respectively. Inorganic elements necessary for human body were found to be abundant in Bangia sp. The results showed that the nutritive value of Bangia sp. was the highest among algae reported so far, and the industry of Bangia sp. was provided with significant economic importance and developing potential.     

中国对虾(Fenneropenaeuschinensis)多性状复合育种方案的遗传和经济评估

设计中国对虾Fenneropenaeus chinensis多性状复合育种方案,模拟选择20个世代,预测和评估目标性状(收获体重(BW),存活率(SR)和饲料摄入量(FI))的遗传进展及经济效益。利用选择指数理论,估计目标性状的选择反应和遗传进展;通过三级金字塔传递系统(核心群、扩繁群和生产群)放大遗传进展并计算其经济效益;对影响利润(RP)和效益成本比率(BCR)的生物学参数(遗传力、育种目标是否包括FI),经济学参数(对虾价格、饲料价格、贴现率、初投资、年费用)和运行参数(首次回报年份、扩繁效率)进行敏感性分析。结果表明,在基础参数值下,BW、SR和FI每个世代的选择反应分别为0.81g、1.41%和1.30g;以1 000尾虾为单位计算,BW、SR和FI的经济加权值分别为32元,20元和-8元,育种目标的遗传进展为43.69元,育种方案执行20年产生的RP和BCR分别为8 660.99万元和14.34。敏感性分析显示,生物学参数中,目标性状遗传力变化对RP和BCR影响程度中等,遗传力值越高,RP和BCR越大;将FI经济加权值设为0,育种方案的RP和BCR明显高于基础参数。经济学参数中,对虾价格的变化对RP和BCR影响较大;饲料价格、贴现率和年费用的变化对RP和BCR影响较小,但初投资变化对BCR影响较大。运行参数中,首次回报年份越晚,RP和BCR越低。扩繁效率是影响RP和BCR的最重要因素。高扩繁效率下,生产群规模扩大1 736.15%,RP和BCR分别提高1 866.92%和1 736.75%。     

Adhesion of pathogenic Vibrio alginolyticus to the gill mucus of Pseudosciaena crocea

Adhesion of Vibrio alginolyticus to the gill mucus of Pseudosciaena crocea has been investigated using [methyl—3H]thymidine as isotope tracer. The results showed that: the adhesive quantity of V. alginolyticus increased with bacterial concentrations and reached equilibrium after incubated for 180 min; the higher adhesive quantity was obtained at 15~30 ℃ and sourish conditions; adhesion of V. alginolyticus could not achieved without Na , and Ca2 played an auxiliary role in the bacterial adhesion; adhesion of V. alginolyticus was inhibited remarkably by starvation, heat treatment and periodic acid treatment; all of the eight kinds of carbohydrates investigated enhanced the adhesion of V. alginolyticus to the gill mucus of P. crocea, among them, glucose, mannose, fructose and maltose showed the specially enhanced adhesion. The results indicated that V. alginolyticus could adhere to the gill mucus of P. crocea facilely in seawater, and this bacterial adhesion was influenced by environmental factors and closely related to superficial carbohydrate structures and some heat-sensitive structures.     

荔枝海绵（Tethya sp.）形态及愈伤过程的观察研究

海绵动物具备很强的愈伤再生能力。荔枝海绵是海绵动物中比较特殊的类群,它有皮质层细胞（cortex）和领细胞层细胞（choanoderm）的初步分化。本文对荔枝海绵的形态结构进行观察,并通过切割的方法,有针对性地移除荔枝海绵的特定结构,观察其愈伤过程,以期了解海绵愈伤过程的主要变化及各部分在愈伤过程中的作用。结果发现,愈伤过程发生的主要变化为未受创部分的细胞向受创部分迁移导致的细胞重新排布;其身体结构中的领细胞层和皮质层对其生存愈伤是必要的,而骨针核心对其愈伤影响较小。     

Influence of diatoms on copepod reproduction. II. Uncorrelated effects of diatom-derived α,β,γ,δ-unsaturated aldehydes and polyunsaturated fatty acids on Calanus helgolandicus in the field

We set up a survey involving comprehensive chemical analyses of phytoplankton and the simultaneous monitoring of the reproductive response of Calanus helgolandicus. Hatching success and larvae development of C. helgolandicus were monitored weekly with female specimens sampled along with phytoplankton in the coastal waters off Roscoff (Western English Channel) from March/April to October in 2003 and 2004. Polyunsaturated aldehyde (PUA) production and nutritional parameters of phytoplankton [i.e. polyunsaturated fatty acids (PUFAs), particulate organic carbon (POC) and nitrogen (PON)] were measured. The hatching success varied between 0% and 80% during the two spring-summer spawning seasons. Neither the nutritional parameters measured nor polyunsaturated aldehydes could be found responsible for the frequently observed hatching failure. However, egg production and hatching rates were strongly positively correlated, suggesting a functional link between these reproductive parameters. PUA production in phytoplankton was mainly determined by Thalassiosira rotula. The occurrence of this diatom species might be used as a marker of PUAs in the study area. Laboratory feeding experiments showed that single species diets of freshly isolated diatoms (T. rotula, Guinardia striata, Guinardia delicatula and Rhizosolenia setigera) caused high or low egg viability and naupliar survival of C. helgolandicus independent of PUA production and PUFA content. The impact of PUA on the hatching success of Calanus among different ecosystems is discussed. The combined approach of feeding experiments and chemical analysis supports the idea that parameters other than PUAs and PUFAs have to be taken into account in order to explain the highly variable hatching rates observed in this environment.     

Study on Kinetics of light-intensity adaptation of Dicrateria inornata

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Trophic ecology of the rocky shore community associated with the Ascophyllum nodosum zone (Roscoff,France): A δC vs δN investigation

This study aimed to characterize the structure and functioning of the benthic food web associated with the Ascophyllum nodosum zone of the rocky shore of Roscoff by using δ¹³C and δ¹⁵N. Several characteristics of the trophic ecology of the invertebrates associated with this mid-littoral habitat and which belong to different functional groups (e.g., grazers, filter-feeders, predators and omnivores) were highlighted. In particular, the filter feeder species (including mostly sponges) used macroalgae-derived organic matter as a substantial food requirement. The results also pointed out an important stable isotopes variability for strict coexisting primary consumers which: (1) is directly related to the high δ¹⁵N range of the food sources; (2) makes it impossible to establish a unique trophic level scale based on δ¹⁵N values, as previously done in coastal environments; and (3) points out the existence of major co-occurring trophic pathways which characterise the Ascophyllum nodosum habitat.