Ports receive a variety of contaminants related to a wide range of anthropogenic activities – including ship ballast water (BW) – that ultimately find their way to sediments. Benthic meiofauna from ...four Adriatic ports (Ancona, Trieste, Koper, and Split) was assessed for the main environmental pollutants, to evaluate the effects of human activities on meiobenthos and identify the most appropriate descriptor to assess the ecological quality of marine ecosystems. Sediment analysis demonstrated that Trieste and Split were the most contaminated ports, followed by Koper and Ancona. All meiofaunal parameters showed high spatial and temporal variability, in line with the marked heterogeneity of the four ports. Sand, total organic carbon, and pollutants seemed to be the variables that best explained meiofaunal patterns. Community structure and rare taxa were the meiofaunal descriptors that reflected the environmental status and biological response most accurately. The present data suggest that meiofauna can be used to assess the biological impact of BW.
•All meiofaunal parameters showed high spatial and temporal variability.•Sand, total organic carbon, and pollutants largely explained meiofaunal patterns.•The meiofaunal community structure mirrored the disturbance gradients.•Meiofauna data add complementary information to assess the BW impact.
Fosillized solid specimens can be identified as Coptocampylodon lineolatus Elliott 1963 in Middle Eocene clastic deep-sea sediments of Istria. Despite their homogenous composition and cylindrical ...shape with longitudinal ribs radiating from rounded poles, which are features commonly observed in coprolites, they have commonly been considered as "incertae sedis". Chemical analysis reveals close similarity between the fossilized specimen and the host marl. These characteristics clearly indicate that the fossilized specimens are coprolites of a deposit feeding, and most probably an invertebrate organism.
The study of small pelagic fish by hydroacoustic methods in the Mediterranean Sea began in the Adriatic in the 1950’s. Since 2009, internationally coordinated, extensive, regular surveys have been ...conducted in the framework of the MEDIAS - Mediterranean International Acoustic Surveys – action, under the EU Data Collection Framework, to provide inputs for the management of small pelagics, particularly European anchovy (Engraulis encrasicolus) and European sardine (Sardina pilchardus). The surveys cover EU Mediterranean waters and monitor the distribution and abundance of small pelagic species using a common protocol. The hydroacoustic surveys, historically conducted by each Country separately, have since been standardized and harmonized. This is a review of the evolution of the surveys from the beginning up to the present and discusses the future prospects. It reports the historical time series of anchovy, sardine and other small pelagics in different areas and describes the spatial and temporal distribution of small pelagic species in decadal maps of the major areas of their distribution in the European Mediterranean Sea. Furthermore, it discusses the use of MEDIAS data for stock assessment purposes, the collection of auxiliary information for an ecosystem-based management approach, the need for further standardization and future challenges.
Allochthonous alga
Caulerpa taxifolia
(Vahl) C. Agardh has been present in the Mediterranean Sea for over thirty years. Different types of negative impacts on species and entire communities have been ...well documented; however, studies of its impact on meiofauna are scarce. The aim of this study was to investigate the structure of meiofauna in the area impacted by the invasive alga,
C. taxifolia
, in the Stari Grad Bay (43.1833°N, 16.5838°E), Adriatic Sea, in December 2008 (autumn) and June 2009 (spring). To establish the nature of the impact on meiofauna inhabiting the sediment of the studied area, we compared the structure of meiofauna inhabiting bare sediments with the structure of meiofauna inhabiting sediments beneath the autochthonous seagrass (
Posidonia oceanica
(L.) Delile) and invasive alga (
C. taxifolia
). Furthermore, comparisons between epibiontic meiofauna inhabiting alga and seagrass were made. Multivariate statistical analysis revealed differences in the composition of meiofaunal assemblages inhabiting unvegetated and vegetated sediments (
P. oceanica
and
C. taxifolia
), during spring. However, no significant differences in composition of meiofauna in sediments inhabited by the invasive alga and those inhabited by the native seagrass were detected. However, the observed impact of
C. taxifolia
on meiofauna in sediment could be characterized as negative, due to the observed decrease of meiofaunal density in sediment inhabited by the aforementioned alga. Considering the epibiontic meiofauna, our study showed that
P. oceanica
increases the meiofaunal density in the Stari Grad Bay ten times as much as the allochthonous, invasive
C. taxifolia
. However, the biodiversity of higher taxonomic categories has not been affected.
Grain size, organic matter and carbonate content were analyzed in 5 Holocene sediment cores from the middle Adriatic. Fine-grained, non-carbonate particles settling prevailed in the investigated ...area. The differences among the stations were influenced by location and hydrodynamic conditions at the sampling sites, by the weathering of the surrounding areas partly under anthropogenic influ-ence and the presence of the remains of the organisms with carbonate skeleton. Even though the east Adriatic coast is mostly carbonate, at the stations near the east Adriatic coast, the presence of the Eocene flysch deposits results in the lower carbonate content (40.27-48.88%) in the sedi-ment with the predomination of silt-sized particles (33.12-56.83%). At the station near Vis Island the sediment is mostly carbonate (67.36-76.5%), with the highest sand content (67.07-70.63%). The source of this sediment are the skeletal remains of the organisms which lived on the seabed, the pre-Holocene sediments and the carbonate rocks from surrounding islands. At the deepest station located closer to the west Adriatic coast clayey particles prevail (52-70%), while carbonate content is low (31.7-40.5%). These clayey particles are the result of the erosion in the Alps and the Apen-nines. These particles have been supplied to the Adriatic Sea mostly by rivers, and subsequently redistributed by the sea current, which carries them along and off the west coast.Original Abstract: Velicina zrna, udio organske tvari i karbonata odredeni su u 5 jezgara holocenskih sedimenta iz srednjeg Jadrana. U istra-ivanom podrucju prevladava talo-enje sitnozrnatih i nekarbonatnih cestica. Na razlike izmedu postaja utjece njihov geografski polo-aj i hidrodinamicki uvjeti na njima, mehanicko tro-enja okolnog podrucja djelomicno pod antropogenim utjecajem ali i prisutnost ostataka organizama s karbonatnim skeletom u sedimentu. Iako je istocna obala Jadrana uglavnom karbonatna, na postajama u blizini istocne obale, prisutnost eocenskih fli-nih naslaga smanjuje udio karbonata (40,27-48,88%) u sedimentu, a prevladavaju cestice velicine mulja (33,12-56,83%). Na postaji u blizini otoka Visa sediment je uglavnom karbonatan (67,36-76,5%), s najvecim sadr-ajem cestica velicine pijeska (67,07-70,63%). Porijeklo ovog sedimenta su skeletni ostaci organizama koji su -ivjeli na morskom dnu, pre-holocenski sedimenti i cestice nastale tro-enjem karbonatnih stijena okolnih otoka. Na najdubljoj postaji koja se nalazi blizu zapadne obale Jadranskog mora prevladavaju cestice velicine gline (52 - 70%), a udio karbonata je nizak (31,7-40,5%). Ove glinene cestice su nastale erozijom Alpa i Apenina, a u Jadransko more su dospjele rijekama, te su morskim strujama pretalo-ene du- zapadne obale.
The aim of the study was to describe epibenthic macroinvertebrates and demersal fish and to identify links between spatial patterns and habitat characteristics (sediment, salinity, oxygen and ...temperature). The research was performed in the Parila lagoon in Croatia; an important nursery ground where conditions in epibenthic community can have significant direct and indirect impact on fisheries. Diversity (30 species) and abundance (from 0 to 7 ind m⁻²) of epibenthic assemblages was low on all stations and showed remarkable seasonal changes. Such patchiness could support the estuarine quality paradox idea, i.e. the most abundant species are well adapted to changing conditions in a variable environment. The ecological analysis showed that total phosphorus concentration (TP), temperature (T) and salinity (S) were the main environmental parameters affecting community structure of the Parila lagoon. Six species listed as frequent (Nerophis ophidion, Zosterisessor ophiocephalus, Syngnathus typhle, Cerastoderma glaucum, Palaemon adspersus and Carcinus aestuarii) have a potential to be used as indicators of habitat quality. In terms of trophic diversity, community was dominated by carnivores and omnivores. Fish trophic index (above 2.7) indicated upward shift of the local food chain and towards mostly carnivorous species, while the absence of herbivorous species pointed to low environmental quality. The present study gives an insight into the current ecological conditions in the Parila lagoon. Further research about the sensitivity of these potential indicators to different types of pressure is necessary in order to select robust earlywarning indicators framework.
The Croatian coastline is long compared with the total national surface area. The coastal zone is mainly karstic and steep, with only one large alluvial plain, and contains approximately one-quarter ...of the total Croatian population. It is an important area for the national economy, particularly tourism and Mediterranean-type agriculture. Sea-level measurements at four points on the east Adriatic coast over the last 40 years indicate differential sea-level trends: from a rise between +0.53 and +0.96 mm/y to a decrease between −0.50 and −0.82 mm/y, a range mainly due to local tectonic activity. In this paper, the effects of assumed 20- and 86-cm sea-level rises on the coastal area are assessed by expert judgement. Coastal areas appear to have, in general, a low vulnerability to changes in sea level. However, some important sites, such as historical town centres, the alluvial plain of the Neretva River, and Vrana Lake on the island of Cres would be seriously endangered. Because of its great length, the entire Croatian coastline cannot be fully protected. Therefore, long-term national adaptation strategies to sea-level rise and plans of actions should be prepared and adopted, and monitoring of the consequences of sea-level rise and further research should be implemented. SAZETAK: Hrvatska je obala veoma dugacka u usporedbi s ukupnom povrsinom zemlje. Obalno je podrucje uglavnom krsevito sa strmom obalom. Obalno podrucje, koje nastanjuje 23% ukupnog broja stanovnistva, je znacajno za nacionalno gospodarstvo, osobito za turizam i Mediteranski tip poljoprivrede. Mjerenja razine mora na cetiri lokacija na istocnoj Jadranskoj obali u posljednjih 40 godina pokazuju, kao rezultat lokalnih dizanja odnosno spustanje obale uslijed tektonskih poremecaja, porast razine izmedju 0.53 i 0.96 mm/godina, odnosno pad razine izmedju 0.50 i 0.82 mm/godina. Procjena utjecaja pretpostavljenog porasta razine mora od 20 i 86 cm na obalno podrucje nacinjena je metodom ekspertske procjene zbog nedostatka odgovarajucih kvantitativnih podataka. Procjenjeno je da u najvecem dijelu obala nije osjetljiva na pretpostavljene promjene. Medjutim, neka znacajna mjesta, kao sto su povijesna sredista nekih gradova, dolina rijeke Neretve i Vransko jezero na otoku Cresu, mogu biti ozbiljno ugrozena. Zbog velike duzine obalne linije sasvim je razumljivo, da se cjelokupna cjelupna linija ne moze u potpunosti zastititi. Stoga je nuzno pripremiti i prihvatiti nacionalnu strategiju za obranu od ocekivanog porasta razine mora te plan i program potrebnih aktivnosti koji treba ukljucivati pracenja utjecaja i istrazivanje na odabranim lokacijama.
Celotno besedilo
Dostopno za:
BFBNIB, DOBA, IZUM, KILJ, NMLJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
The rapidly expanding Atlantic bluefin tuna fattening industry is characterized by high stock densities and a high input food biomass in the form of whole bait seafood. The environmental impact of ...this activity must be effectively monitored within a proper sustainable development framework, to address concerns about the potential adverse effects. However, evaluation of monitoring tools for tuna farming has received less attention than other activities. Based on the principles of key taxa (Pocklington and Wells, 1992), we tested the potential use of changes in benthic macroinvertebrate assemblages, polychaetes and amphipods for this purpose. Applying a non-parametric multivariate approach for monitoring the impact of this aquaculture activity on the benthic habitat, we checked for correlations with the physicochemical environmental variables of the sediment. A hierarchical spatial design was followed, using multiple controls. Amphipods and polychaetes showed dissimilarities between impacted and control locations, with significant differences for total assemblage structure at a taxonomic level of families. Total nitrogen (TN) and total sulfur (TS) concentrations were the variables best associated with these changes for amphipods, and d 13C and total phosphorus (TP) were the best for polychaetes. However, total free sulfides (TFS) and TP were the chemical variables that best indicated the effects on sediment. Using this approach, surrogating the whole benthic assemblage to a single taxocene, our data suggest that monitoring tuna farming impact by comparing the changes in amphipod and polychaete assemblages at family level could be an optimal procedure with an excellent cost/benefit ratio.
Vertical profiles of trace metal (Cd, Pb, Zn, Cu, Ni) concentrations, organic matter content, carbonate content and granulometric composition were determined in two sediment cores from the submarine ...pit Dragon Ear (Middle Adriatic). Concentrations of the analyzed metals (Cd: 0.06-0.12 mg kg⁻¹, Pb: 28.5-67.3 mg kg⁻¹, Zn: 17.0-65.4 mg kg⁻¹, Cu: 21.1-51.9 mg kg⁻¹, Ni: 27.8-40.2 mg kg⁻¹) were in usual range for Adriatic carbonate marine sediments. Nevertheless, concentrations of Cu, Zn, and especially Pb in the upper layer of sediments (top 12 cm) were higher than in bottom layer, while Cd and Ni concentration profiles were uniform. Regression analysis and principal component analysis were used to interpret distribution of trace metals, organic matter and carbonate content in sediment cores. Results of both analysis showed that concentrations of all trace metals in the core below the entrance to the pit were significantly positively correlated with organic matter and negatively correlated with carbonate, while in the core more distant from the entrance only Pb showed significant positive correlation with organic matter. Obtained results indicated that, except for lead which was enriched in surface sediment, in the time of sampling (before the building of the nautical marina) investigated area belonged to unpolluted areas.
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