918 resultados para introduced marine species


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In this study, high-throughput sequencing (HTS) metabarcoding was applied for the surveillance of plankton communities within the southeastern (SE) Baltic Sea coastal zone. These results were compared with those from routine monitoring survey and morphological analyses. Four of five nonindigenous species found in the samples were identified exclusively by metabarcoding. All of them are considered as invasive in the Baltic Sea with reported impact on the ecosystem and biodiversity. This study indicates that, despite some current limitations, HTS metabarcoding can provide information on the presence of exotic species and advantageously complement conventional approaches, only requiring the same monitoring effort as before. Even in the currently immature status of HTS, this combination of HTS metabarcoding and observational records is recommended in the early detection of marine pests and delivery of the environmental status metrics of nonindigenous species.

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[EN] We describe 12 new polymorphic dinucleotide microsatellite loci and multiplex Polymerase Chain Reaction conditions from the loggerhead sea turtle Caretta caretta. Levels of polymorphism were assessed in 50 individuals from the nesting population of the Cape Verde Islands.

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[EN] The presence of Harpa doris Röding, 1798 in marine deposits of the last interglacial period, ~. 130-120. ka (marine isotope stage or MIS 5.5) in the Canary Islands (Gran Canaria, Lanzarote and Fuerteventura) enabled us to compare this occurrence with its present habitat in the Gulf of Guinea and the Cape Verde Islands, well to the south. This comparison leads to the conclusion that sea surface temperatures (SSTs) in the waters around the Canary Islands during the last interglacial period were at least 3.3. °C higher than today. H. doris is found in association with the large gastropod Persististrombus latus (Gmelin, 1791) as well as the coral Siderastrea radians (Pallas, 1766).

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Animal-associated microbiotas form complex communities, which are suspected to play crucial functions for their host fitness. However, the biodiversity of these communities, including their differences between host species and individuals, has been scarcely studied, especially in case of skin-associated communities. In addition, the intraindividual variability (i.e. between body parts) has never been assessed to date. The objective of this study was to characterize skin bacterial communities of two teleostean fish species, namely the European seabass (Dicentrarchus labrax) and gilthead seabream (Sparus aurata), using a high-throughput DNA sequencing method. In order to focus on intrinsic factors of host-associated bacterial community variability, individuals of the two species were raised in controlled conditions. Bacterial diversity was assessed using a set of four complementary indices, describing the taxonomic and phylogenetic facets of biodiversity and their respective composition (based on presence/absence data) and structure (based on species relative abundances) components. Variability of bacterial diversity was quantified at the interspecific, interindividual and intraindividual scales. We demonstrated that fish surfaces host highly diverse bacterial communities, whose composition was very different from that of surrounding bacterioplankton. This high total biodiversity of skin-associated communities was supported by the important variability, between host species, individuals and the different body parts (dorsal, anal, pectoral and caudal fins).

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Seven native and introduced species of fish in south east Caspian Sea coast examined for parasite infestation during 2004-2006. Native fishes include Barbus capito, Carassius auratus, Cyprinus carpio, Rutilus frisii kutum, Rutilus rutilus, Stizostidion lucioperca, Alosa caspia persica, 24 ecto and endo parasites were found in different organs of 7 species of fishes of them 2 of the metazoan 12 species of crustacean Lernaea cyprinacea , Lamproglena pukhella nematodea and cestodea parasite were found and identified to species and genus including: Asymphylodora kubanicums, Caryophylaeus fimbericep, Rhabdochona hellichii, Contracecum sp. (larvae), Pronoprymna, Aspidogaster limacoides, Raphidascaris acus, Caryophylaeus laticeps, Rhabdochona hellichi, Clinostomum complanatum, Hysterothylacium sp., Rhipidocotyle illense of the metzoan 9 monogen species were found and identified to species and genus level including Dactylogyrus frisii, Dactylogyrus nybelini, Dactylogyrus extensus, Gyrodactylus sp, Dactylogyrus baueri, D. formosus, Gyrodactylus sprostonae, Gyrodactylus sp, Mazaocraes alosae. One psecies of digenea parasites belonging to Diplostomatidea family comprised Diplostomum Spathaceum. In comprise infestation parasite of fish species Cyprinus carpio, Rutilus frisii kutum with 25 precent and Stizostidion lucioperca with 5 percent showed the highest and lowest in infection between fishes in comprise ecological region rivers with 45 percent and Estuary 16 percent showed the highest and lowest percent of parasite Infection.

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The status of five species of commercially exploited sharks within the Great Barrier Reef Marine Park (GBRMP) and south-east Queensland was assessed using a data-limited approach. Annual harvest rate, U, estimated empirically from tagging between 2011 and 2013, was compared with an analytically-derived proxy for optimal equilibrium harvest rate, UMSY Lim. Median estimates of U for three principal retained species, Australian blacktip shark, Carcharhinus tilstoni, spot-tail shark, Carcharhinus sorrah, and spinner shark, Carcharhinus brevipinna, were 0.10, 0.06 and 0.07 year-1, respectively. Median U for two retained, non-target species, pigeye shark, Carcharhinus amboinensis and Australian sharpnose shark, Rhizoprionodon taylori, were 0.27 and 0.01 year-1, respectively. For all species except the Australian blacktip the median ratio of U/UMSY Lim was <1. The high vulnerability of this species to fishing combined with life history characteristics meant UMSY Lim was low (0.04-0.07 year-1) and that U/UMSY Lim was likely to be > 1. Harvest of the Australian blacktip shark above UMSY could place this species at a greater risk of localised depletion in parts of the GBRMP. Results of the study indicated that much higher catches, and presumably higher U, during the early 2000s were likely unsustainable. The unexpectedly high level of U on the pigeye shark indicated that output-based management controls may not have been effective in reducing harvest levels on all species, particularly those caught incidentally by other fishing sectors including the recreational sector. © 2016 Elsevier B.V.

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The 42th meeting of the ICES Working Group on Introductions and Transfers of Marine Organisms (WGITMO) was held in Olbia, Italy, 16–18 March 2016, with Anna Occhipinti-Ambrogi as host and Henn Ojaveer as chairperson. Representatives from 19 countries participated in the meeting. Attendants were from Belgium, Canada, Dennark, Estonia, Finland, France, Germany, Ireland, Israel, Italy, Lithuania, Norway, Poland, Portugal, Russia, Spain, Sweden, United Kingdom and United States. Sweden contributed by cor-respondence. The objectives of the meeting were to update information and discuss several aspects related to the introductions and transfers of non-indigenous aquatic species. Data and information management were two of the discussion topics of the meeting, with special focus on the better exploitation of the ‘Information system on aquatic non-indigenous and cryptogenic species’ (AquaNIS). The WGITMO also dedicated time for addressing the MSFD D2 issues: indicator on new non-indigenous species introduced by human activities, and opportunities and problems related to cross-regional comparison of non-indigenous species indicators. Preparation of the manuscript of the alert report on sea squirt Didemnum vexillum, which is to be published in ICES CRR series, was discussed and the steps to be taken to finalise the report were agreed. As usual, adequate time was devoted to discuss national reports, to exchange of information on the management of NIS and to review ongoing and planned research activities. The approach taken during the meeting facilitated presentations and discussions on the issues of relevance related to the Terms of References as well as on a few generic and strategically-important issues of general relevance to bioinvasions. The meeting began with a full-day joint meeting with the Working Group on Ballast and Other Ship Vectors (WGBOSV), which provided an opportunity to discuss and address issues of common interest, such as shipping and biofouling as introduction vectors. The proposed ICES demonstration advice on ‘Risk management of non-indigenous species associated with shipping in the Arctic’ was discussed, and edits were suggested for both the orientation of the demonstration advice as well as for the exact questions to be asked. Both working groups agreed that the practice of conducting back-to-back meetings with one joint day is useful and will continue in 2017. All Terms of References to be addressed for 2016 were discussed. For some Terms of Ref-erence, more detailed presentations were given, and a short overview of the information and subsequent discussion is provided herein at the end of each section. This report is structured so that each Term of Reference is dealt with in sequential order. The main body of the report contains summaries of the presentations and discussions with the more detailed documents being contained in the Annexes. WGITMO progressed each of the Terms of Reference by either completing the task or clearly identifying and agreeing on the inter-sessional activities required to still finalise the work in 2016. From 2017, WGITMO will be shifted to multi-annual management.

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Density, species composition and antimicrobial resistance in bacteria of the Enterococcus genus were evaluated in seawater and sands from 2 marine recreational beaches with different levels of pollution. The 2 beaches showed predominance of Enterococcus faecalis and Enterococcus faecium, in the water and the sand. Dry sand presented higher densities of Enterococcus sp. and higher frequency of resistant strains than wet sand and seawater. The beach with a higher degree of pollution presented higher percentages of resistant strains (66.7% and 61.5%, in sand and in water, respectively) and resistance to a larger number of antimicrobials compared with the less polluted beach, Ilha Porchat (35.7% and 31.25% of resistant strains in sand and water, respectively). in water samples, the highest frequencies of resistance were obtained against streptomycin (38.5%) and erythromycin (25%), whilst in sand, the highest frequencies were observed in relation to erythromycin and tetracycline (38.1% and 14.3%, respectively). These results show that water and sands from beaches with high indexes of faecal contamination of human origin may be potential sources of contamination by pathogens and contribute to the dissemination of bacterial resistance. (C) 2007 Elsevier Ltd. All rights reserved.

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Coastal lagoons are considered one of the most productive areas of our planet harboring a large variety of habitats. Their transitional character, between terrestrial and marine environments, creates a very particular ecosystem with important variations of its environmental conditions. The organisms that are able to survive on these ecosystems frequently experience strong selective pressures and constrictions to gene flowwith marine populations, which could contribute to genetic divergence among populations inhabiting coastal lagoon and marine environments. Therefore, the main aims of this study are to asses the genetic diversity and population structure of Holothuria arguinensis across geographical ranges, to test the hypothesis of coastal lagoons as hotspots of genetic diversity in the Ria Formosa lagoon, and to determine the role of exporting standing genetic variation from the lagoon to open sea and their implications to recent geographical expansion events. To reach these objectives, we investigate the genetic structure of H. arguinensis using two mitochondrial DNA markers (COI and 16S) at different spatial scales: i) small, inside Ria Formosa coastal lagoon, South Portugal; 2) large, including most of the geographical distribution of this species (South and Western Portuguese coast and Canary islands); these results will allow us to compare the genetic diversity of lagoonal and marine populations of H. arguinensis. On this framework, its recent geographical expansion events, recorded by Rodrigues (2012) and González-Wangüemert and Borrero-Pérez (2012), will be analyzed considering the potential contribution from lagoonal genetic pool. Non-significant genetic structure and high haplotypic diversity were found inside the Ria Formosa coastal lagoon. Both genes were unable to detect significant genetic differentiation among lagoonal and marine localities, suggesting a high rate of gene flow. The results supported our hypotheses that coastal lagoons are not only acting as hotspots of genetic diversity, but also contributing for the genetic variability of the species, working as a source of new haplotypes and enhancing adaptation to the high variable conditions. Different genetic patterns of colonization were found on H. arguinensis, but they must be studied more deeply.

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Short-term hooking mortality was evaluated for three sparid species [Diplodus vulgaris (Geoffroy Saint-Hilaire), Spar-us aurata L. and Spondyliosoma cantharus (L.)] in the Algarve, south Portugal. Fishes were caught from the shore during October 2009 at a fish farm reservoir (Ria Formosa), using three different hook sizes. The relationships between hooking mortality and seven independent variables were analyzed using logistic regression models. In all,384 fishes representing the three target species were caught during the angling sessions. The most caught species was S. cantharus (n = 181; 100% undersized), followed by S. aurata (n = 137; 89% undersized) and D. vulgaris (n = 66; 97% undersized). Mortalities ranged between 0% for D. vulgaris and 12% for S. aurata (S. cantharus, 3%). For S. aurora, anatomical hooking location was the main predictor of mortality, with 63% of the fishes that died being deeply hooked. Our results support the current mandatory practices of releasing undersized fish for the studied species, given the low post-release mortality rates observed. (C) 2010 Elsevier B.V. All rights reserved.

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Protein extracts from 22 species of marine macroalgae from Florida and North Carolina were compared for their abilities to agglutinate sheep and rabbit erythrocytes. Protein extracts from 21 algal species agglutinated rabbit erythrocytes compared to 19 for sheep erythrocytes. However, agglutination by brown algal extracts was variable. The agglutination produced by protein extracts from Dictyota dichotoma could be blocked by addition of polyvinylpyrrolidone. Protein extracts from North Carolina macroalgae were also tested against five bacterial species. Three of these agglutinated bacterial cells. Ulva curvata and Bryopsis plumosa agglutinated all five species. Protein extracts from five species of Florida algae were tested for their effects on mitogenesis in mouse splenocytes and human lymphocytes. Gracilaria tikvahiae HBOI Strain G-5, Ulva rigida and Gracilaria verrucosa HBOI Strain G-16S stimulated mitogenesis in mouse splenocytes, while Gracilaria tikvahiae HBOI Strain G-16stimulated mitogenesis in human lymphocytes.

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The stochastic simulation algorithm was introduced by Gillespie and in a different form by Kurtz. There have been many attempts at accelerating the algorithm without deviating from the behavior of the simulated system. The crux of the explicit τ-leaping procedure is the use of Poisson random variables to approximate the number of occurrences of each type of reaction event during a carefully selected time period, τ. This method is acceptable providing the leap condition, that no propensity function changes “significantly” during any time-step, is met. Using this method there is a possibility that species numbers can, artificially, become negative. Several recent papers have demonstrated methods that avoid this situation. One such method classifies, as critical, those reactions in danger of sending species populations negative. At most, one of these critical reactions is allowed to occur in the next time-step. We argue that the criticality of a reactant species and its dependent reaction channels should be related to the probability of the species number becoming negative. This way only reactions that, if fired, produce a high probability of driving a reactant population negative are labeled critical. The number of firings of more reaction channels can be approximated using Poisson random variables thus speeding up the simulation while maintaining the accuracy. In implementing this revised method of criticality selection we make use of the probability distribution from which the random variable describing the change in species number is drawn. We give several numerical examples to demonstrate the effectiveness of our new method.

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Three native freshwater crayfish Cherax species are farmed in Australia namely; Redclaw (Cherax quadricarinatus), Marron (C. tenuimanus), and Yabby (C. destructor). Lack of appropriate data on specific nutrient requirements for each of these species, however, has constrained development of specific formulated diets and hence current use of over-formulated feeds or expensive marine shrimp feeds, limit their profitability. A number of studies have investigated nutritional requirements in redclaw that have focused on replacing expensive fish meal in formulated feeds with non-protein, less expensive substitutes including plant based ingredients. Confirmation that freshwater crayfish possess endogenous cellulase genes, suggests their potential ability to utilize complex carbohydrates like cellulose as nutrient sources in their diet. To date, studies have been limited to only C. quadricarinatus and C. destructor and no studies have compared the relative ability of each species to utilize soluble cellulose in their diets. Individual feeding trials of late-juveniles of each species were conducted separately in an automated recirculating culture system over 12 week cycles. Animals were fed either a test diet (TD) that contained 20% soluble cellulose or a reference diet (RD) substituted with the same amount of corn starch. Water temperature, conductivity and pH were maintained at constant and optimum levels for each species. Animals were fed at 3% of their body weight twice daily and wet body weight was recorded bi-weekly. At the end of experiment, all animals were harvested, measured and midgut gland extracts assayed for alpha-amylase, total protease and cellulase activity levels. After the trial period, redclaw fed with RD showed significantly higher (p<0.05) specific growth rate (SGR) compare with animals fed the TD while SGR of marron and yabby fed the two diets were not significantly different (p<0.05). Cellulase expression levels in redclaw were not significantly different between diets. Marron and yabby showed significantly higher cellulase activity when fed the RD. Amylase and protease activity in all three species were significantly higher in the animals fed with RD (Table 1). These results indicate that test animals of all species can utilize starch better than dietary soluble cellulose in their diet and inclusion of 20% soluble cellulose in diets does not appear to have any significant negative effect on their growth rate but survival was impacted in C. quadricarinatus while not in C. tenuimanus or C. destructor.

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In this paper, we report the preparation and characterisation of nanometer-sized TiO2, CdO, and ZnO semiconductor particles trapped in zeolite NaY. Preparation of these particles was carried out via the traditional ion exchange method and subsequent calcination procedure. It was found that the smaller cations, i.e., Cd2+ and Zn2+ could be readily introduced into the SI′ and SII′ sites located in the sodalite cages, through ion exchange; while this is not the case for the larger Ti species, i.e., Ti monomer [TiO]2+ or dimer [Ti2O3]2+ which were predominantly dispersed on the external surface of zeolite NaY. The subsequent calcination procedure promoted these Ti species to migrate into the internal surface of the supercages. These semiconductor particles confined in NaY zeolite host exhibited a significant blue shift in the UV-VIS absorption spectra, in contrast to the respective bulk semiconductor materials, due to the quantum size effect (QSE). The particle sizes calculated from the UV-VIS optical absorption spectra using the effective mass approximation model are in good agreement with the atomic absorption data.