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The microhabitat preferences and depth distribution of blenniid species (Blenniidae) in the Gulf of Trieste (North Adriatic Sea) were surveyed using the all‐occurrence sampling method, a non‐destructive visual census method, aided by SCUBA diving. Fourteen species were identified during the entire survey. Four species showed to be indiscriminate in their microhabitat choice while 10 species were classified as infrequent in the surveyed coastal area. A statistically significant correlation was found between the blenniid assemblage and nine microhabitat variables. The blenniid assemblage was divided in two main groups, by the use of canonical correspondence analysis, electivity index, and the depth distribution analysis. The first group comprises species that dwell in surface waters and show a high positive correlation with boulders, the presence of Mytilus galloprovincialis, cirripeds and empty holes bored by Lithophaga lithophaga. The second group includes species that mostly inhabit deeper waters and show a high positive correlation with rocks covered by precoralligenous bioformations. 相似文献
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Benthic macrophytes as a tool for delineating, monitoring and assessing ecological status: the case of Slovenian coastal waters 总被引：1，自引：0，他引：1
Benthic macrophytes from 51 sites in the upper infralittoral zone along the Slovenian rocky coast were sampled (randomly stratified) in order to (1) confirm water body (WB) boundaries, (2) select sampling points for a surveillance monitoring programme, and (3) assess preliminary Ecological Status Classes (ESC) within the European Water Framework Directive (WFD). Coverage data of macrophytes were analyzed by using cluster analysis, Simper analysis and the Ecological Evaluation Index (EEI). The vegetation was rather homogenously classified into two Cystoseiretum crinitae subassociations: Halopithetosum incurvae, and Cystoseiretosum compressae, and into Cystoseiretum barbatae association. Seven monitoring sites at a kilometer scale were selected in two significant sized WBs following the mixing zone principle and the EEI successional model. The preliminary assessment of the ESC with the EEI was in agreement with existing human pressures in the area. In view of the present results, benthic macrophytes and EEI could be valuable tools for the implementation of the WFD within the Mediterranean eco-region. 相似文献
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Routine monitoring of the quality status of water bodies demands the best cost‐benefit relation and sample‐size reduction is therefore welcomed. However, great caution is needed because such reduction affects the accuracy and variation of the results. In the present study we tested the influence of sample size (number of replicate samples) on reference condition values and within‐sample ecological quality ratio (EQR) variability of six commonly used ecological indices (taxa richness, Shannon–Wiener diversity, AMBI, Medocc index, Bentix and M‐AMBI). Analysis of soft‐bottom benthic invertebrate data from Slovenian coastal waters showed that sample size influenced the reference condition values of richness/diversity indices (taxa richness and Shannon–Wiener diversity) but not of the sensitivity/tolerance indices (AMBI, Medocc index, Bentix). Increased sample size decreased the within‐sample EQR variability and, concomitantly, increased the accuracy of site ecological status classification for all indices. The size of EQR variability differed depending on the index used. EQR variability of M‐AMBI, an index composed of metrics with different within‐sample EQR variability, was statistically the same as that of the metric with the lowest within‐sample EQR variability. Whether this is a common principle for multimetric indices remains to be confirmed. Based on these results, the use of at least three replicates is suggested to obtain reliable measures of reference condition and EQR for the assessment of ecological status. This level of replication is particularly necessary in areas with high diversity and environmental patchiness, and when richness/diversity measures and indices that include these measures are used. 相似文献
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Coastal Fish Diversity in Three Marine Protected Areas and One Unprotected Area in the Gulf of Trieste (Northern Adriatic) 总被引：1，自引：0，他引：1
Abstract. The coastal fish assemblage in three protected sites and one unprotected area in the Slovenian part of the Gulf of Trieste (Northern Adriatic) was studied. Species composition and richness were comparable at all studied sites, including the control, unprotected area. Differences in fish density between the protected area of Debeli rti? and the unprotected area of Fiesa‐Pacug were revealed using correspondence analysis. Particularly the densities of certain labrid species (Symphodus cinereus and S. roissali) were higher in the protected area. Those differences are attributable to the extended and densely vegetated infralittoral belt of the Debeli rti? area rather than to its protected status. 相似文献
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Factors affecting habitat occupancy of fish assemblage in the Gulf of Trieste (Northern Adriatic Sea) 总被引：3，自引：0，他引：3
Species composition, richness and abundance of the fish assemblage were studied over six different inshore macrohabitats in the southern part of the Gulf of Trieste (Northern Adriatic Sea) using the visual counts technique. Fifteen environmental variables were taken into consideration in order to determine microhabitat preferences of fish species, using canonical correspondence analysis and electivity indices. The results suggest that the structure of the fish assemblage in shallow habitats is affected by a large number of interplaying factors. Depth, type of bottom and vegetation cover – incorporating both abiotic and biotic variables – are some of the factors responsible for coastal fish distribution. Microhabitat preferences for 29 fish species are presented in the depth range from 0.5 to 3 m. 相似文献
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Adriatic ‘opisthobranchs’ (Gastropoda,Heterobranchia): shedding light on biodiversity issues 
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下载免费PDF全文 Argyro Zenetos Vesna Mačić Andrej Jaklin Lovrenc Lipej Dimitris Poursanidis Riccardo Cattaneo‐Vietti Sajmir Beqiraj Federico Betti Diego Poloniato Lefter Kashta Stelios Katsanevakis Fabio Crocetta 《Marine Ecology》2016,37(6):1239-1255
We herein review the Adriatic opisthobranch fauna, provide an updated checklist of 223 species and assess their distribution at regional and country levels. New Adriatic records are provided for 67 opisthobranch taxa, adding three new records for the Italian coastline, five new records for Albania, eight for Croatia and 15 for Montenegro. The presence of Hermaea bifida (Montagu, 1815), Hermaea variopicta (Costa A., 1869) and Facelina annulicornis (Chamisso & Eysenhardt, 1821) is reported for the first time from anywhere in the Adriatic Sea. Including the new findings, our inventory includes 28 species from Albania, 163 from Croatia, 178 from the Italian coastline of the Adriatic, 41 from Montenegro and 74 from Slovenia. No records were available from Bosnia and Hercegovina. Ninety species (40.4%) are widespread, and were recorded from all three main divisions (Northern, Western and Eastern Adriatic), whilst 79 species (35.4%) were reported from only one of them. At sub‐division levels, the Albanian inventory is the most dissimilar to the other country/regional lists, presumably because of the lack of targeted field surveys. The highest similarity is observed amongst the Western Adriatic, Croatia and the Italian Ionian coastline. Seven alien, one possible alien and three cryptogenic opisthobranchs were reliably recorded from the Adriatic Sea. The first Mediterranean records of five species were in the Adriatic Sea, of which four species have not been found elsewhere in the Mediterranean. Shipping and aquaculture are the probable pathways for most of the alien species. A steady rate of one to two alien introductions per decade since the 1970s was evident. The Northern Adriatic coasts are the most affected by alien invasions, probably due to repeated local introductions along with shellfish transfers (oysters, mussels, Manila clams), and heavy maritime transport. 相似文献
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