The effect of season and sex on trophic levels of marine fishes

The diet of 76 species from Greek waters (north Aegean Sea) was examined for the determination of trophic level by species, season and sex. Trophic level estimates were derived from TrophLab software based on collected stomach content data. Such estimates are important for the implementation of marine management indicators, such as the marine trophic index. The mean ± s . e . difference between minimum and maximum trophic levels among seasons within species was 0·45 ± 0·04 and for 28·8% of the species this difference was larger than the corresponding s . e . of the trophic level of the pairs of seasons examined. Depending on which seasonal trophic level ( i.e. autumn, winter, spring or summer) was used for assigning a species into a functional trophic group 33·9 and 8·5% of the species changed one and more than one group, respectively. Finally, the mean ± s . e . absolute difference of male and female trophic level was 0·18 ± 0·02, and only for 6·6% of the species this difference was larger than the s . e . of trophic level for each sex separately. Depending on the trophic level used for assigning the species into a functional group ( i.e. male v. female), only 6·6 and 3·2% of the species changed one and more than one groups, respectively. It is therefore clear that all measures used in this study indicated that the effect of season on trophic level estimates was higher, compared to that of sex, the latter being of minor importance to feeding studies. Hence, future effort on stomach content analysis should focus on the examination of seasonal, small to moderate sample sizes.     

Ultrastructural and biochemical studies on Candida albicans after prolonged incubation in sea water

Abstract Candida albicans yeast cells suspended in sterilized sea water and cultivated in Brain Heart Infusion broth were compared. Viability, chemical composition, surface hydrophobicity and ultrastructural characteristics showed variations after incubation in sea water. The yeast cells developed some ultrastructural changes after about a month in sea water. The surface hydrophobicity of the yeast cells was gradually reduced, starting from day 16, and continued to decline throughout the 32 days in sea water. A decrease in total carbohydrate, lipid and protein contents was also observed and corresponded with ultrastructural modifications.     

Comparative Characterization of the Microbial Community in Two Species of Sponges from Sea of Japan Using Fatty Acid Markers

The fatty acid composition of total lipids in two species of sponges (Halichondria panicea and Clathria pennata) inhabiting the same biotope in the Sea of Japan was examined. More than 80 fatty acids (FAs) were found for each species of sponges. Of them, 61 fatty acids were identified for H. panicea and 54 for C. pennata. The relative content of most FAs was less than 1%. The contribution of symbiotic microorganisms to the total fatty acids was higher in H. panicea than in C. pennata. Bacterial symbionts and microeukaryotes were found among the microorganisms associated with the sponges. The contribution of prokaryotic organisms was equal (7.8%) for both species of sponges, but the fatty acids were characteristic of different taxonomic groups of bacteria. The proportion of microeukaryotic fatty acids in the total lipids of H. panicea (19.6%) was two times that of C. pennata (10.1%).     

Long-term changes in the status of Sevastopol Bay and the Crimean coast: anthropogenic and climatic influences

The Black Sea as a whole is subject to considerable anthropogenic and natural pressures, and these can be intensified in enclosed Bays such as those around the city of Sevastopol. The overall biological status of Sevastopol Bay has improved considerably in the last 30 years or so. The number of macrobenthic species in the Bay has increased from just over 20 in 1973 to around 70 in 2000, and there have been similar enrichments in abundance, in biomass and in diversity (H′). The same pattern is shown in other locations such as the Southern Bay (the most highly polluted of the embayments) from which macrofauna were completely absent in 1976 and 1982. Over the same period oil hydrocarbons in sediments of the Southern Bay have actually increased from 8760 mg kg⁻¹ in 1976 to 12,020 mg kg⁻¹ in 2002, while the levels in the open sea sediments have decreased slightly over the same period (450 mg kg⁻¹ and 280 mg kg⁻¹, respectively). Moreover, this pattern of biological improvement is also seen outside the Bay, suggesting a common factor in the changes. Since the effect of the local factors (i.e. pollution) can be readily seen in the gradient of biological response among sites, yet they have not significantly changed over the period of study, the overall improvement must involve some over-arching driver such as climatic influences. This point is discussed further in relation to the wider changes in the Black Sea system. Guest editors: J. Davenport, G. Burnell, T. Cross, M. Emmerson, R. McAllen, R. Ramsay & E. Rogan Challenges to Marine Ecosystems     

Three millennia of human and sea turtle interactions in Remote Oceania

Sea turtles are one of the largest vertebrates in the shallow water ecosystems of Remote Oceania, occurring in both sea grass pastures and on coral reefs. Their functional roles, however, over ecological and evolutionary times scales are not well known, in part because their numbers have been so drastically reduced. Ethnographic and archaeological data is analysed to assess long-term patterns of human–sea turtle interactions (mainly green and hawksbill) prior to western contact and the magnitude of turtle losses in this region. From the ethnographic data two large-scale patterns emerge, societies where turtle capture and consumption was controlled by chiefs and priests versus those where control over turtle was more flexible and consumption more egalitarian. Broadly the distinction is between societies on high (volcanic and raised coral) islands versus atolls, but the critical variables are the ratio of land to shallow marine environments, combined with the availability of refugia. Archaeological evidence further highlights differences in the rate and magnitude of turtle losses across these two island types, with high islands suffering both large and rapid declines while those on atolls are less marked. These long-term historical patterns help explain the ethnographic endpoints, with areas that experienced greater losses apparently developing more restrictive social controls over time. Finally, if current turtle migration patterns held in the past, with annual movements between western foraging grounds and eastern nesting beaches, then intensive harvesting from 2,800 Before Present in West Polynesia probably affected turtle abundance and coral reef ecology in East Polynesia well before the actual arrival of human settlers, the latter a process that most likely began 1,400 years later.     

Composition of the genus Leptosagitta of the family Sagittidae (Chaetognatha) with descriptions of four new species from coastal waters of the Northwestern Sea of Japan

Keys for the identification of the presently known species of the genus Leptosagitta (fam. Sagittidae) are presented. Four new species of this genus found in shallow waters of Vostok Bay, Amursky Bay (Peter the Great Bay), and Kievka Bay (all of the Sea of Japan) are described in detail: L. kiyashkoi sp. n., L. latyshevi sp. n., L. magna sp. n., and L. pauca sp. n.     

Cytokine mediated proliferation of cultured sea turtle blood cells: Morphologic and functional comparison to human blood cells

Blood cells from three different sea turtle species were cultured for approximately 3 weeks in nutrient medium supplemented with recombinant human cytokines known to induce terminal maturation of human hematological stem cells. Cultured turtle erythrocytes were translucent, approximately 10× larger than human erythrocytes, contained a single fluorescent inclusion body, contained nuclear epsilon (embryonic) globin proteins, and, absent of organelles while fresh cells contained few, but well defined mitochondria. Cells with basophilic cytoplasm and in all stages of proliferation were observed in cytokine-supplemented cultures and appeared to possess active protein synthesis. Cultured thrombocytes aggregated in response to agonists for at least 8 days, post-collection, contained P-selectin in the nucleus of 6 day cultured cells which appeared to be released after activation with collagen, and after 6 days had no organelles or open canalicular-like system (OCS) while freshly isolated cells demonstrated few, if any organelles but had a well developed OCS. The response of turtle cells to apparently homologous but unnatural human cytokines and the sustained biological properties of thrombocytes identify this suspension culture system as a powerful tool to explore the evolution of cell types and molecular components of hematopoiesis and hemostasis.     

Beta-carotene studies in Spirulina

The increasing importance of natural beta-carotene in fighting xerophthalmia and cancer has given special importance to algal sources of beta-carotene. The susceptibility to quick degradation of this valuable nutrient in oxygen atmosphere, light or heat calls for specific attention to processing and storage practices. In the case of Spirulina it was found that initial losses of beta-carotene on spray drying were between 7 and 10%. On storage in coloured bottles containing air, more than 50% was lost in less than 45 days. The particle size of the dried material seems to have an influence. Flakes (about 20 mesh+) retained 52% of the original beta-carotene level while the spray-dried fine powder (100 mesh-), retained only 34% of the original level. This is explainable in terms of surface area available for active reaction which is higher in the powder than in flakes. This questions the suitability of using spray drying for Spirulina drying. In this paper, data will be presented to substantiate the behaviour of beta-carotene on drying and storage by various methods.