0000000000133762
AUTHOR
Roberto Danovaro
Microbial and meiofaunal response to intensive mussel-farm biodeposition in coastal sediments of the Western Mediterranean
We studied the impact of organic loads due to the biodeposition of a mussel farm in a coastal area of the Tyrrhenian Sea (Western Mediterranean). Sediment chemistry, microbial and meiofaunal assemblages were investigated from March 1997 to February 1998 on monthly basis at two stations: the first was located under the mussel farm, while the second was at about 1-km distance and served as control. Benthic response to changes in the biodepositional regime was investigated in terms of biochemical composition of the sedimentary organic matter, phytopigment content, bacterial abundance and composition and meiofaunal community structure. A large accumulation of chloroplastic pigments, proteins an…
Impact on the water column biogeochemistry of a Mediterranean mussel and fish farm
We investigated and compared the impact of organic loads due to the biodeposition of mussel and fish farms on the water column of a coastal area of the Tyrrhenian Sea (Western Mediterranean). Physico-chemical data (including oxygen, nutrients, DOC and particulate organic matter), microbial variables (picoplankton and picophytoplankton density and biomass) and phytoplankton biomass (as chlorophyll-a) were determined on a monthly basis from March 1997 to February 1998. The results of this study indicate that both fish farm and mussel culture did not alter significantly dissolved inorganic phosphorus and chlorophyll-a values, while inorganic nitrogen concentrations were higher in mussel farm a…
Enzymatically hydrolyzable protein and carbohydrate sedimentary pools as indicators of the trophic state of detritus sink system: a case study in a Mediterranean Coastal lagoon
In order to classify the trophic state of 'detritus sink' systems, instead of the conventional indicators based on inorganic nutrient availability and algal biomass and productivity in the water column, we utilized new biochemical descriptors based on the amount of sedimentary organic carbon and nitrogen potentially available to heterotrophic nutrition. We investigated spatial and temporal changes in microphytobenthic biomass, organic matter biochemical composition and enzymatically hydrolyzable protein and carbohydrate pools along a N-S transect in the Marsala lagoon (Mediterranean Sea, Italy) at three stations characterized by different hydrodynamic conditions and organic matter content i…
The Pillars of Hercules as a bathymetric barrier to gene flow promoting isolation in a global deep-sea shark (Centroscymnus coelolepis).
Catarino, Diana ... et. al.-- 19 pages, 5 figures, 4 tables, data accessibility http://dx.doi.org/10.5061/dryad.ss368, supporting information http://dx.doi.org/10.1111/mec.13453
Differential response of benthic microbes and meiofauna to fish-farm disturbance in coastal sediments
Bacterial and meiofaunal abundance and biomass and their response to the disturbance induced by fish-farm biodeposition were investigated from March to October 1997 on a monthly basis at two stations of the Gaeta Gulf (Tyrrhenian Sea, Mediterranean Sea). The biopolymeric fraction of the organic matter was characterized by high concentrations which was similar at both fish-farming-impacted and control stations. Similarly, bacteria accounted for a small fraction of the biopolymeric organic carbon (<1%), while the contribution due to auto-fluorescent cell biomass (i.e. prokaryotic and eukaryotic cells displaying auto-fluorescence) to the total biopolymeric carbon was quantitatively negligible …
Nematode community response to fish-farm impact in the western Mediterranean.
A previous investigation on fish-farm biodeposition effects on benthos, carried out in the Gaeta Gulf (northwestern Mediterranean Sea), revealed a strong impact on meiofaunal assemblages. This study implements these findings by examining in detail the nematode assemblage and its response to organic enrichment from the start of a fish farm activity to the conclusion of the fish rearing cycle. Density, community structure and individual size were utilised for univariate (genus, trophic diversity and abundance patterns) and multivariate analyses (MDS) in order to identify the best descriptors of impact and the response of the nematode assemblages. Nematodes displayed significantly reduced dens…
Initial Fish-Farm Impact on Meiofaunal Assemblages in Coastal Sediments of the Western Mediterranean
We studied the initial impact of organic loads due to the biodeposition of a new fish farm in a non-impacted coastal area of the Tyrrhenian Sea (Western Mediterranean). Sediment chemistry and meiofaunal assemblages were investigated from July 1997 to February 1998 on a monthly basis at two stations: the first was located under the fish farm, while the second was at about 1 km distance, and served as control. Variations in the biochemical composition of the sedimentary organic matter and meiofaunal community structure were also related to changes in reared fish biomass. The presence of the cage-induced rapid changes in the benthic compartment: the sediments reached rapidly (i.e., after only …
Influence of artificial reefs on the surrounding infauna: Analysis of meiofauna
We adopted a bottom-up approach in studying the effect of two artificial reefs in contrasting environmental conditions (sandy-mud and meso-eutrophic in the Adriatic Sea versus coarse sands and oligotrophic in the Tyrrhenian Sea) on the surrounding environment by assessing changes in the meiofauna. The spatial distribution of meiofaunal assemblages was established along a transect running from within each reef to well outside its direct sphere of influence, along with information on the trophic conditions of sediments (chloropigments, proteins, carbohydrates and total organic matter). Although total densities were significantly higher in the Adriatic than in the Tyrrhenian, the meiofauna dis…
Aquaculture impact on benthic microbes and organic matter cycling in coastal Mediterranean sediments: a synthesis
Microbial assemblages and organic matter composition as well as their response to the disturbance induced by mussel and fish-farm biodeposition were compared in several areas of the Mediterranean: La Spezia (Ligurian Sea), Gaeta (Tyrrhenian Sea), Cattolica (Adriatic Sea) and Cyprus (Levantine Sea), on both unvegetated and Posidonia bed sediments. In all systems investigated, organic matter (as biopolymeric carbon) accumulated in aquaculture impacted sediments. Among the main biochemical classes, lipids appeared to be a good tracer of aquaculture impact, especially in fish-farm sediments. Exoenzymatic activities displayed higher values in sediment beneath the cages, indicating faster organic…
Fish-farming effects on benthic community structure in coastal sediments: analysis of meiofaunal recovery
To study the impact of organic enrichment and high biodeposition caused by intensive fish farming in coastal sediments, meiofaunal samples were collected on a monthly basis between March and October 1997 at two stations of the Gaeta Gulf: One under the Farmocean cage (2000 m3), while the other (the control) was located at about 1 km from an area not impacted by fish farming. The fish farm contained about 120 000 Dicentrarchus labrax (density 18 kg m -3). The most evident changes in the benthic habitat under the cage were a large accumulation of primary organic material (phytopigment concentrations up to 44 μg g-1), changes in sedimentary organic matter composition (increased lipid levels re…
Data from: The Pillars of Hercules as a bathymetric barrier to gene-flow promoting isolation in a global deep-sea shark (Centroscymnus coelolepis)
Knowledge of the mechanisms limiting connectivity and gene-flow in deep-sea ecosystems is limited, especially for deep-sea sharks. The Portuguese dogfish (Centroscymnus coelolepis) is a globally distributed and Near Threatened deep-sea shark. C. coelolepis population structure was studied using 11 nuclear microsatellite markers and a 497 bp fragment from the mtDNA Control Region. High levels of genetic homogeneity across the Atlantic (ΦST=-0.0091, FST= 0.0024, P > 0.05) were found suggesting one large population unit at this basin. The low levels of genetic divergence between Atlantic and Australia (ΦST= 0.0744, P<0.01; FST=0.0015, P > 0.05) further suggested that this species may …