Comparative study of otolith and sulcus morphology for stock discrimination of yellow drum along the Chinese coast

Otolith morphology is widely used for fish stock identification. The sulcus, a structure on the medial side of the otolith, is an important feature in morphological analysis. This study was conducted to evaluate the feasibility of using sulcus morphology for stock identification and to compare its performance with commonly used otolith morphology analysis. Otoliths were collected and analyzed from three geographical groups (the Huanghe (Yellow) River estuary, HHE;the Jiaozhou Bay, JZB;and the Changjiang (Yangtze) River estuary, CJE) of yellow drum Nibea albiflora. The results show that the analysis of sulcus morphology based on shape indices (SIs), elliptic Fourier coefficients (EFc), and a combination of the two parameters identified stocks at overall classification rates of 51.0%, 72.5%, and 73.2%, respectively. These classification rates are similar to those obtained using otolith morphology analysis (57.0%, 73.8%, and 76.5% by SIs, EFc, and their combination, respectively). The findings suggest that sulcus morphology is comparable to the commonly used otolith morphology for identifying stocks of sciaenids, such as the yellow drum. For both otolith and sulcus morphology, EFc could identify the stocks more efficiently than SIs, while the combination of SIs and EFc was even better.     

Applicability and intercalibration of macrophyte quality indices to characterise the ecological status of Mediterranean transitional waters: the case of the Venice lagoon

In the framework of the WFD 2000/60/EC intercalibration process the updated versions of the EEI and R‐MaQI, proposed by Italy and Greece for the transitional waters, have been applied to the macrophytes of the Venice lagoon to test their comparability and relationships with the pressure gradients. Submerged macrophytes were collected during spring 2007 at 60 sites spread within the lagoon. At each site, five random samples were collected and the total coverage of benthic macrophytes in the field was estimated based on a number of tests of the bottom. To assess seagrass epiphytes, five shoots were collected for each replicate. Physico‐chemical data were collected in the water column at 14 sites selected to reflect the main hydro‐geomorphological and trophic gradients of the lagoon. The analyses performed indicated that the two metrics appeared to be weakly intercalibrated and only the 30% of the sampling sites displayed the same quality class. The main differences fell into the Moderate and Low classes and the two indices provided discordant results in the intermediate and confined areas of the lagoon. In contrast, the two indices showed good affinity in the marine areas of inlets, which are characterised by seagrass meadows and late‐successional macroalgae. Similar results were evidenced also in a redundancy analysis by the different relationships between quality classes and the physico‐chemical gradients. The main reason for this seems to be the heterogeneity of species–environment relationships inside the groups of species on which the indices are based. Critical aspects of methodological differences and applicability of the macrophyte indices proposed by Italy and Greece for the transitional waters of the Mediterranean eco‐region are discussed.     

Relationships between land use and stream invertebrate community structure in a South Island,New Zealand,coastal stream catchment

Macroinvertebrate community composition was compared across streams draining catchments dominated by either native bush, agricultural or urban land uses within the Water of Leith stream catchment near Dunedin, New Zealand. Land use was associated with differences in taxon richness and faunal composition of communities present in each stream. The mean abundance levels of Ephemeroptera, Plecoptera, and Trichoptera were highest in native bush catchments, and lowest in urban catchments. In contrast, the mean abundance of Oligochaeta exhibited the opposite pattern. Increasing dominance of the urban and agricultural streams by pollution tolerant taxa was reflected in the Macroinvertebrate Community Index and Quantitative Macroinvertebrate Community Index scores.     

Interannual variability in the biochemical composition of newly hatched larvae of the spider crab Maja brachydactyla (Decapoda,Majidae)

The spider crab Maja brachydactyla is an important commercial species in Europe and supports intensive fisheries in the NE Atlantic. A field survey was performed to assess long‐term and consecutive interannual (2005–2010) variation of the biochemical composition of newly hatched larvae of M. brachydactyla. Larval biochemical profiles differed significantly among years, with pronounced differences being recorded in 2010. Differences among batches of newly hatched larvae were mainly explained by the contribution of triacylglycerols and, to a lesser degree, by protein and lipid content. The use of different nutrition indices is discussed. The biochemical composition of newly hatched larvae from M. brachydactyla was highly variable, even though surveyed broodstock was obtained from the same local population and was always sampled during the same season. The unpredictable biochemical profiles of newly hatched larvae may condition their survival and recruitment. This largely overlooked aspect of larval variability should be considered in future fisheries management strategies and captive production of marine organisms that still rely on wild seeds.     

运用德尔菲调查—灰色统计法确立水库鱼产力综合评价中的指标权重体系

本文运用德尔菲方法对水库鱼产力综合评价中指标权重的合理分配问题作了专家调查,并采用灰色统计法对调查结果进行归纳处理,从而确立了一个水库鱼产力影响因素诸层次各方面的评价指标权重体系,可供今后的评价工作参考使用。     

The Würm in NW Iberia, a pollen record from Area Longa (Galicia)

The pollen record at Area Longa is the westernmost sequence available for investigation of the last glaciation in continental Europe. It is located in a region, NW Iberia, for which data from times earlier than the late glacial period are scarce. It comprises a series of exposed limnetic levels that lie above an Eemian (Oxygen Isotope Stage [OIS] 5e) beach and are separated by inorganic layers. The oldest limnetic level (Level I), attributed to the early glacial period (OIS 5a to OIS 5d), shows a dominance of woodland with high proportions of Fagus pollen and is tentatively identified with St. Germain I. The lower pleniglacial (OIS 4) Level II records a stadial landscape of grassland and shrub. Level III, from the pleniglacial interstade (OIS 3), reflects a complex period in which three warmer woodland phases alternated with periods of more open vegetation. This cyclical behavior correlates with the ice core isotope record and with the general tendencies observed in other Würmian pollen records, but the composition of our pollen profiles differs from those observed in these other records. In NW Iberia, the dominant trees were deciduous taxa, not conifers. Of particular note is the presence of lowland Fagus woodlands during the pre-Würm, and the occurrence of Carpinus considerably farther west than the boundary of its current distribution in the Iberian Peninsula.     

Application of organic petrology and geochemistry to coal waste studies

Coal wastes produced during mining activities are commonly deposited in nearby dumps. These wastes mostly composed of minerals and variable amounts (usually 20-30%) of organic matter start to weather immediately after deposition. Oxidation of the organic matter can lead to self heating and self combustion as a result of organic and mineral matter transformations. The degree of alteration depends on the properties of the wastes, i.e., the maceral and microlithotype composition of the organic matter and its rank.Alteration of wastes also depends on the heating history, i.e., the rate of heating, final heating temperature, duration of heating, and the degree of air access. Although air is probably necessary to initiate and drive the heating processes, these usually take place under relatively oxygen depleted conditions. With slow heating, color of organic matter particles changes, irregular cracks and oxidation rims develop around edges and cracks, and bitumen is expelled. As a result, massive and detritic isotropic and strongly altered organic matter forms. On the other hand, higher heating rates cause the formation of devolatilization pores, oxidation rims around these pores and along cracks, vitrinite-bands-mantling particles, and bitumen expulsions.Organic compounds generated from the wastes include n-alkanes, iso-alkanes, alkylcyclohexanes, acyclic isoprenoids, mainly pristane, phytane and, in some cases, farnesane, sesquiterpanes, tri- and tetracyclic diterpanes, tri- and pentacyclic triterpanes, and steranes, polycyclic aromatic hydrocarbons (mostly with two- to five rings, rarely six rings), and phenols. The compounds formed change during the heating history. The fact that phenols are found in dumps where heating has not yet been completed, but are absent in those where heating ceased previously suggests the presence of water washing. The organic compounds formed may migrate within the dumps. However, when they migrate out of the dumps, they become a hazard to environment.This paper is a review on transformations of organic matter (both maceral composition and reflectance and chemical composition) in coal wastes deposited in coal waste dumps. Immediately after deposition the wastes are exposed to weathering conditions and sometimes undergo self heating processes.     

Structuring factors of the spatio-temporal variability of macrozoobenthos assemblages in a southern Mediterranean lagoon: How useful for bioindication is a multi-biotic indices approach?

The authors investigated the impact of the extension of the El Kantra Channel on the composition and structure of macrobenthic assemblages in Boughrara Lagoon (Gulf of Gabes, Tunisia along with the use of 4 biotic indices (AMBI, BENTIX, M-AMBI and TUBI). Thirteen stations were sampled seasonally in 2012–2013. Forty-one species were found in 2012–2013 not recorded in 2009–2010, including 20 species of polychaetes belonging to the trophic groups of deposit-feeders and carnivores which are expected to increase in areas disturbed by organic pollution. During the survey, we recorded a high fish mortality, essentially caused by the development of harmful algal blooms (HAB) which increased organic matter deposition, thus inducing polychaete development. This seems to weaken the bio-indicating power of biotic indices used here which, paradoxically, classified all sampled stations at a high ecological status. A review of these indices and their applicability to all marine environments is recommended.     

重庆金佛山岩溶作用驱动因素初探

走向北东-南西向的向斜和近东西向的横张大节理等地质构造控制了金佛山岩溶作用发生的空间展布方向.下二叠统的中厚层块状灰岩及生物碎屑灰岩给金佛山岩溶作用的发生提供了坚实的物质基础.4~10月这一温暖湿润的气候特征加大了金佛山岩溶作用发生的强度和速度.茂密的森林植被和及其植被分带性在进一步促进了金佛山岩溶作用发生的同时,也导致了金佛山岩溶作用强度在时空分布上的差异.     

规则波在缓坡上变形与破碎数值分析

通过在二维数值水槽内用边界元法直接求解Laplace方程,对规则波在缓坡上的变形及破碎进行了数值计算。分析了不同底坡及采用不同底摩阻系数时规则波的破碎特征,并对规则波破碎的极限坡度进行了研究。重点分析了规则波破碎时海底坡度、底摩阻系数及波形不对称性对破碎指标的影响。