1,721,017 research outputs found
Experimental co-culture of low food-chain organisms, Sabella spallanzanii (Polychaeta, Sabellidae) and Cladophora prolifera (Chlorophyta, Cladophorales), in Porto Cesareo area (Mediterranean Sea)
No full textThe filter feeder polychaete Sabella spallanzanii (Gmelin) was co-cultured with the green seaweed Cladophora prolifera (Roth.) Kunz, in an off-shore experimental system. Both species have previously been experimented as bioremediator organisms for waste treatment deriving from aquaculture farms and can have a high economic value as a byproduct of polyculture. The present experiment has been conducted in an area 2 miles off the coast of Porto Cesareo (Ionian sea, Southern Italy). The growth was followed in some modules anchored to the bottom at two different depths (15 and 25 m depth). The results indicate differences among replicates located at different depths. Both organisms show a faster growth at the shallower levels. Within this level, polychaetes reached a mean biomass of 860 +/- 74 mg dw (average +/- SE) per worm, 30 times larger than that of the starting point, after a standstill in the first period, probably due to the manipulation activities. The major growth has been recorded during the winter. Algae have shown an increase of 34 g ww month(-1) (average +/- SE) in the shallower levels vs. only 11 g ww month(-1) (average +/- SE) in the deeper levels. The RGR calculated after 60 days was 115% in the shallower levels vs. about 60% in the deeper ones. A considerable decrease in growth rate was observed during the last period; this was probably due to the presence of increasing fouling community on the rearing cages surely affecting the light intensit
Ammonium uptake of Cladophora prolifera (Chlorophyta, Cladophorales) a candidate species for bioremediation of aquaculture wastes
No full textPresence of Celleporaria brunnea (Bryozoa: Lepraliellidae) in the Central Mediterranean: First occurrence in the Gulf of Taranto
No full textWe report the presence of the non-indigenous species (NIS) Celleporaria brunnea (Bryozoa, Ascophora) in the Central
Mediterranean. It was found in the Gulf of Taranto (Ionian Sea, southern Italy), which represents one of the most important
hotspots for NIS in the Mediterranean. Using PVC plates as species collectors, immersed in different times of the year, we
observed a recruitment of C. brunnea during the warmer period of the year from July to October. This work highlights a
range expansion of C. brunnea and provides information about its autoecology traits in the host environmen
Variability of fouling communities in the Mar Piccolo of Taranto (Northern Ionian Sea, Mediterranean Sea)
No full textIn order to investigate the intensity and variability of fouling recruitment on artificial hard substrates, three sites were chosen in the First Inlet of the Mar Piccolo of Taranto (Southern Italy, Ionian Sea). Taxa richness and percentage coverage were examined in three different sampling times within each site. Differences were tested both by univariate and multivariate statistical analysis (ANOVA, SIMPER and MDS). The results show that each site seems to be characterized by its own structural make-up over the whole period of observation, underlying the presence of large-scale variability. By contrast, variability on a smaller scale within each site (replicates) appeared less marked, both in space and time. A set of a quite stable group of species characterized each site. Differences between sites were maintained over time with a difference in community evolution although with a tendency towards a higher similarity in species composition along the time. Copyright © Marine Biological Association of the United Kingdom 2010
Settlement and population dynamics of the alien invasive Branchiomma bairdi (Annelida: Sabellidae) in the Mediterranean Sea: two years of observations in the Gulf of Taranto (Italy)
No full textSince the first discovery along the Italian coasts in 2004 of the polychaete Branchiomma bairdi, it
has spread very quickly, reaching some localities in very high densities. In order to monitor its
colonization, recruitment was investigated by means of PVC panels immersed in the Mar
Grande of Taranto (Ionian Sea). Panels were monitored every three months from April 2013
to January 2015. The species showed the ability to settle on bare panels as well as on panels
with a developed fouling community. Two years of monitoring identified two different
cohorts, with recruits appearing in both years on panels submersed from July to October.
Based on these observations B. bairdi is a short-lived species (no more than one year),
reproducing at a temperature ranging from 20 to 29°C and reaching sexual maturity three
months after recruitment. Oocytes were found in the coelom only in the warmest months
and oogenesis was not synchronous either within each individual or within the population.
Total annual secondary production was estimated at 43.42 g m−2 year−1. Annual mean
biomass was 20.03 g m−2. The corresponding P/B ratio was 2.1678. This study may explain
the invasiveness of B. bairdi; indeed, a rapid generation turnover coupled with a short
lifespan, rapid growth and early maturity are common traits in most invasive species
A model of environmental suitability for the conservation of the loggerhead turtle Caretta caretta in the Southern Adriatic and Northern Ionian Sea (Central Mediterranean Sea).
No full textWe present a preliminary model of environmental suitability for the conservation of the loggerhead turtle Caretta caretta in the Southern Adriatic and Northern Ionian Sea. Data from stranding, bycatch, nesting and home range from telemetries from 1994 to 2013 were considered. Environmental data from nesting sites were used to compute a MaxEnt model of nesting suitability. Data from each set were then combined into a map subdivided into 5 km × 5 km cells to assess the environmental suitability of each cell. Preliminary data suggest that the model is useful to locate the areas of maximum suitability to concentrate efforts of monitoring and conservationWe present a preliminary model of environmental suitability for the conservation of the loggerhead turtle Caretta caretta in the Southern Adriatic and Northern Ionian Sea. Data from stranding, bycatch, nesting and home range from telemetries from 1994 to 2013 were considered. Environmental data from nesting sites were used to compute a MaxEnt model of nesting suitability. Data from each set were then combined into a map subdivided into 5 km × 5 km cells to assess the environmental suitability of each cell. Preliminary data suggest that the model is useful to locate the areas of maximum suitability to concentrate efforts of monitoring and conservation
Consequences of the experimental removal of Sabella spallanzanii (Gmelin, 1791) from fouling assemblage of a Mediterranean harbour
Full text linkFilter feeding invertebrates are a relevant component of fouling assemblages with a pivotal role in ecological processes, since
they improve water quality, enhance habitat heterogeneity and transfer organic matter from the water column to the benthos. They
modulate the availability of resources to other species, with effects on the density and behavior of the surrounding macrofauna.
The fanworm Sabella spallanzanii, one of the largest and most abundant Mediterranean filter feeders, provides a shelter for predation
and a secondary substrate for algae and settlement for sessile invertebrates. We tested its role in driving the structure of fouling
assemblages, through a removal experiment.
The experiment was one-year-long, with four sampling times. The effect of the removal on the fouling community was marginal
in terms of species richness and evenness, while the biomass showed important differences, with a constant increase over time
with higher values in the samples containing S. spallanzanii. At the end of observations, the biomass reached the value of 3917 g
DW m-2 in controls and 2073 g DW m-2 in treatments. The empty space left by fanworms was not used by other species with similar
biomasses. It is possible that the functioning of fouling communities may, in the event of loss of species, fluctuate in terms of
biomass mobilization to different compartments, either towards the pelagic compartment or to the detritus chain. In systems with
reduced water turnover, this by-pass can have important consequences in terms of stability and ecological balance
Sponges associated with coralligenous formations along the Apulian coasts
Full text linkSponge assemblages associated with coralligenous outcrops were studied with the aim of describing and comparing their composition, morphological features and distribution at different depths (shallow vs. deep) along the Apulian coasts. In addition, image analysis enabled the description of the main features of coralligenous outcrops and the detection of structuring species. The paper provides a significant contribution in terms of supplying new taxa of sponges associated to coralligenous assemblages and emphasising the importance of invertebrates in realising calcareous constructions. Most of the new finding came from deep sites, thus underlining the need to improve taxonomic studies on coralligenous communities at greater depths. A total of 153 taxa of sponges were recorded: 4 Calcarea, 6 Homoscleromorpha and 143 Demospongiae. Two species, Clathria (Microciona) macrochela and Thoosa armata, are new records for the Italian sponge fauna, with C. (M.) macrochela representing a new record for the whole Mediterranean. New findings for the Ionian and Adriatic Seas totalled 25 and 8 species, respectively. Thirty-nine species are endemic for the Mediterranean. Data analyses clustered sites into two groups, separated according to the depth. Deep sites, characterised by animal dominance, exhibit a heterogeneous substrate texture richer in cavities than the shallow and homogeneous algal ones. Differences in sponge species composition also correspond to differences in the distribution of sponge growth forms, with the insinuating cryptic species more abundant in deeper communities. Ten of 15 sponge species included in national and international wildlife protection laws and policy have been detected in the present study
Chaetomorpha linum in the bioremediation of aquaculture wastewater: Optimization of nutrient removal efficiency at the laboratory scale
Full text linkMarine pollution from aquaculture wastewater is a widespread and increasing ecological problem. Algae, with their ability to remove surplus nutrients from wastewater, are a good tool for achieving more sustainable aquaculture. In this study, the capability of different biomasses of Chaetomorpha linum and Cladophora prolifera for the bioremediation of nutrient-rich (ammonium, nitrate and phosphate) seawater was compared. The results suggest that 10 g L−1C. linum is an excellent candidate for aquaculture wastewater bioremediation. However, the bioremediation efficiency of C. linum was significantly affected by seasonality, with the greatest performance in nutrient removal exhibited by algae harvested in summer. C. linum harvested in winter and acclimated to lab conditions for two months, significantly improved the removal efficiency of both ammonium and nitrate, while worsening that of phosphate. Irrespective of season and acclimation, the simultaneous presence of ammonium and nitrate in seawater strongly inhibited nitrate removal. Thus, we propose the use of a two-step system, tested at the laboratory scale, in which nutrient-enriched seawater can pass through two different algal ponds. C. linum was able to achieve almost complete removal of ammonium in 24 h in the first step, while the second step improved both nitrate and phosphate removal efficiency. The two-step system is an effective innovation for the use of algae in bioremediation of aquaculture wastewaters
Trophic flexibility and prey selection of the wild long-snouted seahorse Hippocampus guttulatus Cuvier, 1829 in three coastal habitats
Full text linkThe present study examined the dietary composition of long-snouted seahorse H. guttulatus Cuvier, 1829 in Mar Piccolo of Taranto (Apulia, Italy)using a non-destructive flushing method. To assess differences in the selection of prey among different habitats, adult specimens were collected from both highly complex (Cladophora prolifera and Corallina elongata)and low complex (unvegetated Sandy bottom)habitats. Additionally, samples of benthic fauna were collected from the same habitats and were used to investigate the local availability of potential preys. Results showed significant differences in the diet composition among three studied habitats. Consistently with the results of faunal analysis, gut contents of specimens sampled on C. elongata had higher prey abundance and diversity compared to the other two habitats. Dietary composition of seahorses found in the vegetated habitats was similar, and it was mainly based on Amphipoda and Copepoda. However, small prey (<1 mm)was more consumed on C. elongata than on C. prolifera. On the sandy bottom, H. guttulatus preyed mainly on small crustaceans, but actively selected larger prey (i.e. Galathoidea and Paguroidea). Nematodes were also highly preyed in all habitats, although the high consumption could be possibly attributed to the high abundance and availability of these organisms at the investigated site. H. guttulatus showed a great ability to exploit available resources in the best possible manner among different habitats, acting as a specialist predator. With an aim to understand the use of food resources that are available in the environment, the results of this study could help to propose initiatives directed to the seahorse conservation. Since prey availability does not seem to be a limiting factor in the understanding of variability and consistency of H. guttulatus populations, further studies on other environmental and biological aspects could be useful in the assessment of the conservation status of long-snouted seahorses
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