Search results for "Fish Farming"
showing 10 items of 115 documents
Population structure and recruitment of the ectoparasite Argulus coregoni Thorell (Crustacea: Branchiura) on a fish farm
2003
The population structure and recruitment of Argulus coregoni was monitored at a Finnish fish farm during the open water periods of 1999 and 2001 by weekly sampling of attached argulids. In 2001 the numbers of rainbow trout examined increased in the autumn when the A. coregoni population was declining. When the water temperature exceeded 10 degrees C, at the end of May, A. coregoni egg hatching commenced. A mean number of 98 (S.D. +/- 5.4) juvenile A. coregoni was recorded on each fish, before the start of female egg laying in July 1999. The abundance of lice was lower in 2001. The main recruitment of A. coregoni juveniles occurred in early summer, but the hatching of eggs continued until Se…
The effect of intermittent feeding on feed intake and compensatory growth of whitefish Coregonus lavaretus L.
2009
Abstract Groups of juvenile whitefish, Coregonus lavaretus , were exposed for 6 weeks to three different feeding regimes: control (fed every day); 2 + 5 (fed during weekdays); and 2 + 2 (fed 2 days, starved 2 days). The fish in the 2 + 2 group ate and grew less than the controls but the 2 + 5 group was intermediate and did not differ statistically significantly from either of the other two groups. The fish in both treatment groups exhibited clear compensation for the reduced number of feeding days by increasing intake and consequently weight gain during the days when they were fed, and the compensation increased towards the end of the experiment. Feeding treatments induced clear changes in …
Animal fouling as an indicator of water quality in Mediterranean fish farmed areas
2010
In the Mediterranean, most of the fish farm plants are located in very deep water columns (>20-30 m) and are characterised by energetic hydrodynamic regime levels. Thus, the effects of farming load...
Meiofauna as indicator for assessing the impact of fish farming at exposed marine site
2012
This study aimed to detect the impact of organic loads due to biodeposition from a fish farm in an exposed area of the Strait of Sicily, Mediterranean Sea. Sediment chemistry and meiofaunal assemblages were investigated on a seasonal basis at four stations: two from the impacted area and two control stations. The presence of the cages induced a significant accumulation of proteins, lipids and biopolymeric carbon, resulting in a reduction in meiofaunal density at the impacted stations. Changes in community structure were also evident, as meiofauna under the cages were characterized by increased importance of polychaetes and copepods in comparison with a much lower importance of gastrotrichs …
Benthic microbial indicators of fish farm impact in a coastal area of the Tyrrhenian Sea
2004
Abstract We studied the impact of organic loads due to the biodeposition of a fish farm in a non-impacted coastal area of the Tyrrhenian Sea (Western Mediterranean). Sediment chemistry and benthic microbial community were investigated from July 1997 to February 1998 on monthly basis at two stations: one was located under the fish farm, while the second was about 1 km away, and served as a reference site. The presence of the cage induced rapid changes in the benthic conditions: the sediments were rapidly (after 6 weeks) reduced. A significant accumulation of biopolymeric carbon was observed beneath the cage both 2 weeks after the initial cage deployment, on non-impacted sediments, and 5-7 mo…
Impact on the water column biogeochemistry of a Mediterranean mussel and fish farm
2002
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…
The Fish Pathogen Vibrio vulnificus Biotype 2: Epidemiology, Phylogeny, and Virulence Factors Involved in Warm-Water Vibriosis
2015
ABSTRACT Vibrio vulnificus biotype 2 is the etiological agent of warm-water vibriosis, a disease that affects eels and other teleosts, especially in fish farms. Biotype 2 is polyphyletic and probably emerged from aquatic bacteria by acquisition of a transferable virulence plasmid that encodes resistance to innate immunity of eels and other teleosts. Interestingly, biotype 2 comprises a zoonotic clonal complex designated as serovar E that has extended worldwide. One of the most interesting virulence factors produced by serovar E is RtxA1 3 , a multifunctional protein that acts as a lethal factor for fish, an invasion factor for mice, and a survival factor outside the host. Two practically id…
The use of phage FCL-2 as an alternative to chemotherapy against columnaris disease in aquaculture
2015
Flavobacterium columnare, the causative agent of columnaris disease in fish, causes millions of dollars of losses in the US channel catfish industry alone, not to mention aquaculture industry worldwide. Novel methods are needed for the control and treatment of bacterial diseases in aquaculture to replace traditionally used chemotherapies. A potential solution could be the use of phages, i.e., bacterial viruses, host-specific and self-enriching particles that can be can easily distributed via water flow. We examined the efficacy of phages to combat columnaris disease. A previously isolated phage, FCL-2, infecting F. columnare, was characterized by sequencing. The 47 142 bp genome of the phag…
Ingestion of plastic and non-plastic microfibers by farmed gilthead sea bream (Sparus aurata) and common carp (Cyprinus carpio) at different life sta…
2021
Environmental pollution by plastic particles is of major global concern, as a potential threat to aquatic organisms and ecosystems. The accumulation of microplastics in freshwater and marine environments has strong ecological implications due to their long persistence, potential toxicity, and ability to adsorb other pollutants, acting as vectors of pathogens. Nevertheless, while the number of studies on the presence of microplastics in the wild fish increased, less attention has been paid to the farmed fish species. Here, we investigated the occurrence of microparticles in the digestive tracts of Sparus aurata and Cyprinus carpio at different life stages and reared by an intensive and semi-…
Comparative morphometrics of sharpsnout seabream (Diplodus puntazzo Cetti, 1777), reared in different conditions
1999
The same genetic stock of sharpsnout seabream (Diplodus puntazzo), cultured in different conditions (lot A, monoculture tank; lot B, monoculture offshore cage; lot C, polyculture tank), was analysed using geometric morphometrics in order to detect changes in shape. Rearing in the offshore cage (lot B) had a significant effect on shape variation when compared to rearing in the two enclosed tanks (A and C). Fish from the tanks show a higher frequency (43.7% in lot A and 37.5% in lot C) of the so-called ‘goitred’ and ‘dorsal flat’ forms, their deformations shown by displacements in the corresponding landmarks of the infraopercular and dorsal areas. In contrast, the so-called ‘belly’ fish were …