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Terje Jahnsen - One of the best experts on this subject based on the ideXlab platform.

  • regulating the local environmental impact of intensive marine Fish farming ii the monitoring programme of the mom system modelling ongrowing Fish Farms monitoring
    Aquaculture, 2001
    Co-Authors: Pia Kupka Hansen, Arne Ervik, Morten Schaanning, Per Johannessen, Jan Aure, Terje Jahnsen, Anders Stigebrandt
    Abstract:

    A programme for monitoring the impact of organic waste from marine Fish Farms is presented. . It consists of three types of investigation of increasing complexity and accuracy A, B and C , which are applied more frequently with increasing environmental impact. The A-investigation is a simple measurement of sedimentation rate beneath the net cages; the B-investigation is a sediment investigation providing a trend monitoring of the sediment condition, and the C-investigation is a comprehensive investigation of the benthic macrofaunal community structure. The A- and B-investigations were designed specifically for Fish farming and the latter utilises several parameters in order to make the investigation more robust. The C-investigation employs well- established methods and procedures, which have been used previously in monitoring programmes. . Environmental quality standards EQS have been set for the B- and C-investigation. The monitoring programme is part of a larger management system in Norway called Modelling- . Ongrowing Fish Farms-Monitoring MOM . q 2001 Elsevier Science B.V. All rights reserved.

  • regulating the local environmental impact of intensive marine Fish farming i the concept of the mom system modelling ongrowing Fish Farms monitoring
    Aquaculture, 1997
    Co-Authors: Arne Ervik, Pia Kupka Hansen, Per Johannessen, Jan Aure, Anders Stigebrandt, Terje Jahnsen
    Abstract:

    Abstract The paper describes the concept of a management system called MOM (Modelling-Ongrowing Fish Farms-Monitoring) which may be used to adjust the local environmental impact of marine Fish Farms to the holding capacity of the sites. The concept is based on integrating the elements of environmental impact assessment, monitoring of impact and environmental quality standards (EQS) into one system. The amount of monitoring is dependent on the level of the environmental impact. Two terms are introduced: (1) the degree of exploitation, which is an expression of how much the site is being utilised, and (2) the level of monitoring, which determines the amount of monitoring depending on the environmental impact. For Norwegian conditions, a monitoring programme, including EQS, has been developed concerning the impact on the sediment under Fish Farms. It consists of three types of investigations of increasing elaboration and accuracy. A model, which simulates the environmental impact on a site given information about the farm's size and production and the hydrodynamic conditions and topography of the site, has been developed but not yet tested. The model and the monitoring programme with EQS are only briefly described, but will be published later. The MOM system should help to maintain satisfactory environmental conditions in and around Fish Farms and may be a valuable tool in site selection and coastal zone management.

Anders Stigebrandt - One of the best experts on this subject based on the ideXlab platform.

  • regulating the local environmental impact of intensive marine Fish farming ii the monitoring programme of the mom system modelling ongrowing Fish Farms monitoring
    Aquaculture, 2001
    Co-Authors: Pia Kupka Hansen, Arne Ervik, Morten Schaanning, Per Johannessen, Jan Aure, Terje Jahnsen, Anders Stigebrandt
    Abstract:

    A programme for monitoring the impact of organic waste from marine Fish Farms is presented. . It consists of three types of investigation of increasing complexity and accuracy A, B and C , which are applied more frequently with increasing environmental impact. The A-investigation is a simple measurement of sedimentation rate beneath the net cages; the B-investigation is a sediment investigation providing a trend monitoring of the sediment condition, and the C-investigation is a comprehensive investigation of the benthic macrofaunal community structure. The A- and B-investigations were designed specifically for Fish farming and the latter utilises several parameters in order to make the investigation more robust. The C-investigation employs well- established methods and procedures, which have been used previously in monitoring programmes. . Environmental quality standards EQS have been set for the B- and C-investigation. The monitoring programme is part of a larger management system in Norway called Modelling- . Ongrowing Fish Farms-Monitoring MOM . q 2001 Elsevier Science B.V. All rights reserved.

  • regulating the local environmental impact of intensive marine Fish farming i the concept of the mom system modelling ongrowing Fish Farms monitoring
    Aquaculture, 1997
    Co-Authors: Arne Ervik, Pia Kupka Hansen, Per Johannessen, Jan Aure, Anders Stigebrandt, Terje Jahnsen
    Abstract:

    Abstract The paper describes the concept of a management system called MOM (Modelling-Ongrowing Fish Farms-Monitoring) which may be used to adjust the local environmental impact of marine Fish Farms to the holding capacity of the sites. The concept is based on integrating the elements of environmental impact assessment, monitoring of impact and environmental quality standards (EQS) into one system. The amount of monitoring is dependent on the level of the environmental impact. Two terms are introduced: (1) the degree of exploitation, which is an expression of how much the site is being utilised, and (2) the level of monitoring, which determines the amount of monitoring depending on the environmental impact. For Norwegian conditions, a monitoring programme, including EQS, has been developed concerning the impact on the sediment under Fish Farms. It consists of three types of investigations of increasing elaboration and accuracy. A model, which simulates the environmental impact on a site given information about the farm's size and production and the hydrodynamic conditions and topography of the site, has been developed but not yet tested. The model and the monitoring programme with EQS are only briefly described, but will be published later. The MOM system should help to maintain satisfactory environmental conditions in and around Fish Farms and may be a valuable tool in site selection and coastal zone management.

Pablo Sanchezjerez - One of the best experts on this subject based on the ideXlab platform.

  • influence of aquaculture waste on fatty acid profiles and gonad maturation of wild Fish aggregations at Fish Farms
    Marine Environmental Research, 2020
    Co-Authors: Daniel Gonzalezsilvera, David Izquierdogomez, Pablo Sanchezjerez, Maria Teresa Elbal, Jose Angel Lopezjimenez, Francisco Javier Martinezlopez
    Abstract:

    Abstract Wild Fish belonging to four species belonging to different trophic groups were captured at three distances from Fish farm facilities: long distance (>5 Km), medium distance (1.5 Km) and close to sea-cages. Flesh, brain, liver and gonads were sampled for fatty acid analysis. Fish aggregated near sea-cages showed accumulation of fatty acids of vegetable origin in the studied tissues, due to surplus feed consumption or via predation of Fish that consumed the feed. Gonads accumulated vegetable fatty acids in different manner in the different species, and the species least and most influenced by Fish-feeds were selected for gonad histological examination. Results showed an acceleration of the final stages of the oocyte development in Fish aggregated near Fish Farms compared to Fish captured at long distance. Differences in oocyte development were more acute in the species which incorporated higher quantities of vegetable fatty acids.

  • waste feed from coastal Fish Farms a trophic subsidy with compositional side effects for wild gadoids
    Estuarine Coastal and Shelf Science, 2011
    Co-Authors: Damian Fernandezjover, Pablo Sanchezjerez, Ingebrigt Uglem, Just T Baylesempere, Laura Martinezrubio, Jose Angel Lopez Jimenez, F Lopez, Palarne Bjorn, Tim Dempster
    Abstract:

    Aquaculture of carnivorous Fish species in sea-cages typically uses artificial feeds, with a proportion of these feeds lost to the surrounding environment. This lost resource may provide a trophic subsidy to wild Fish in the vicinity of Fish Farms, yet the physiological consequences of the consumption of waste feed by wild Fish remain unclear. In two regions in Norway with intensive aquaculture, we tested whether wild saithe (Pollachius virens) and Atlantic cod (Gadus morhua) associated with Fish Farms (Fassoc), where waste feed is readily available, had modified diets, condition and fatty acid (FA) compositions in their muscle and liver tissues compared to Fish unassociated (UA) with Farms. Stomach content analyses revealed that both cod and saithe consumed waste feed in the vicinity of Farms (6e96% of their diet was composed of food pellets). This translated into elevated body and liver condition compared to Fish caught distant from

  • movements of grey mullet liza aurata and chelon labrosus associated with coastal Fish Farms in the western mediterranean sea
    Aquaculture Environment Interactions, 2010
    Co-Authors: Pablo Arechavalalopez, Pablo Sanchezjerez, Ingebrigt Uglem, Damian Fernandezjover, Just T Baylesempere, Rune Nilsen
    Abstract:

    Grey mullet occur in abundance around sea bream and sea bass Farms where they for- age on waste Fish feed, a behaviour that could modify their natural movement pattern and distribu- tion. In this study, we used visual census to record grey mullet aggregations at Fish Farms in the west- ern Mediterranean Sea. We also mapped the movements of 2 species (Liza aurata and Chelon labrosus) between Farms and adjacent coastal Fishing areas, using acoustic telemetry. Grey mullet were frequently observed in the vicinity of the aquaculture cages and represented an important abundance and biomass at the Farms. The presence and swimming depth of the tagged mugilids at any of the Farms were neither significantly related to the time of the day nor the feeding period, except for C. labrosus, which showed a tendency towards deeper waters (~15 m) during feeding peri- ods. Some of the tagged Fish stayed in the vicinity of the Farms for longer periods and also moved fre- quently to other Farms and nearby commercial Fishing areas. Other tagged Fish remained at the release location for shorter periods, before they moved out of the study area or possibly were caught by local Fishermen. This is the first study using acoustic tagging in wild Fish around Mediterranean Fish Farms that demonstrates that offshore aquaculture Farms and local Fishing grounds in the western Mediterranean Sea are connected through movements of wild Fish. These Farms attract and affect large numbers of commercially important Fish species; probably causing ecological changes not only in the immediate proximity of Farms but also several kilometres away from the Farms.

  • changes in body condition and fatty acid composition of wild mediterranean horse mackerel trachurus mediterraneus steindachner 1868 associated to sea cage Fish Farms
    Marine Environmental Research, 2007
    Co-Authors: Damian Fernandezjover, Pablo Sanchezjerez, Just T Baylesempere, Jose Angel Lopez Jimenez, Francisca Gimenez Casalduero, Francisco J Lopez, Tim Dempster
    Abstract:

    Net-cage Fish Farms attract a great number of wild Fishes, altering their behaviour and possibly their physiology. Wild Mediterranean horse mackerel (Trachurus mediterraneus), sampled from populations aggregated around two Mediterranean Fish Farms and from two natural control populations, were analyzed for differences in body condition, stomach content and fatty acid composition. Pellets used to feed caged Fish in both Farms were also analyzed to identify their relationship with the fatty acid composition of tissue of wild Fish. T. mediterraneus aggregated around the Farms throughout the year although large seasonal changes in abundance and biomass occurred. Wild Fish aggregated at Farms mainly ate food pellets while control Fish fed principally on juvenile Fish and cephalopods. Wild Fish that fed around the cages had a significantly higher body fat content than the control Fish (7.30+/-1.8% and 2.36+/-0.7%, respectively). The fatty acid composition also differed between farm-associated and control Fish, principally because of the significantly increased levels of linoleic (C18:2omega6) and oleic (C18:1omega9) acids and decreased docosahexaenoic acid (C22:6omega3) in farm-associated Fish. The increased condition of wild Fish associated with Farms could increase the spawning ability of coastal Fish populations, if wild Fish are protected from Fishing while they are present at Farms. The fatty acids compositions could also serve as biomarkers to infer the influence of a Fish farm on the local Fish community, helping to better describe the environmental impact of Fish farming.

  • multivariate analysis of the bentho demersal ichthyofauna along soft bottoms of the eastern atlantic comparison between unvegetated substrates seagrass meadows and sandy bottoms beneath sea cage Fish Farms
    Marine Biology, 2005
    Co-Authors: Fernando Tuya, Pablo Sanchezjerez, Arturo Boyra, Ricardo Haroun
    Abstract:

    By means of multivariate techniques, we studied: (1) the differences in the structure of bentho-demersal, non-cryptic, Fish assemblages associated with unvegetated sandy substrates, vegetated meadows constituted by the seagrass Cymodocea nodosa and the bottoms under the influence of sea-cage Fish Farms; as well as (2) the persistence of these patterns with regard to different scales of spatial variability, across three islands of the Canarian Archipelago (Central East Atlantic). Our sampling strategy (involving three islands, with five locations per island, and two sites within each location) detected significant changes in the composition and structure of the Fish assemblages between the three habitats. Fish assemblages associated with the unvegetated and vegetated bottoms were similar among the surveyed islands. In contrast, we observed a significant inter-island variability in the Fish populations associated with the sea-cage Fish Farms. The presence of the sea-cage Fish Farms increased the overall Fish abundance (184.8±49.8 ind 100 m−2) as compared to both the vegetated (38.8±9.7 ind 100 m−2) and unvegetated habitats (1.1±0.4 ind 100 m−2). Differences within and between the habitats were found to be associated with the relative abundance of a few Fish species. The most abundant species were Xyrichthys novacula in the unvegetated bottoms and Diplodus annularis, Spondyliosoma cantharus and Mullus surmuletus on the seagrass meadows. Finally, we recorded an increase in the abundance of Heteroconger longissimus, Trachinus draco and Pagellus acarne in the bottoms beneath the sea-cage Fish Farms. These species, in addition to a group of large benthic chondrichthyes, were responsible for the differences between islands in the composition and structure of the demersal ichthyofauna beneath the sea-cage Fish Farms.

Arne Ervik - One of the best experts on this subject based on the ideXlab platform.

  • regulating the local environmental impact of intensive marine Fish farming ii the monitoring programme of the mom system modelling ongrowing Fish Farms monitoring
    Aquaculture, 2001
    Co-Authors: Pia Kupka Hansen, Arne Ervik, Morten Schaanning, Per Johannessen, Jan Aure, Terje Jahnsen, Anders Stigebrandt
    Abstract:

    A programme for monitoring the impact of organic waste from marine Fish Farms is presented. . It consists of three types of investigation of increasing complexity and accuracy A, B and C , which are applied more frequently with increasing environmental impact. The A-investigation is a simple measurement of sedimentation rate beneath the net cages; the B-investigation is a sediment investigation providing a trend monitoring of the sediment condition, and the C-investigation is a comprehensive investigation of the benthic macrofaunal community structure. The A- and B-investigations were designed specifically for Fish farming and the latter utilises several parameters in order to make the investigation more robust. The C-investigation employs well- established methods and procedures, which have been used previously in monitoring programmes. . Environmental quality standards EQS have been set for the B- and C-investigation. The monitoring programme is part of a larger management system in Norway called Modelling- . Ongrowing Fish Farms-Monitoring MOM . q 2001 Elsevier Science B.V. All rights reserved.

  • regulating the local environmental impact of intensive marine Fish farming i the concept of the mom system modelling ongrowing Fish Farms monitoring
    Aquaculture, 1997
    Co-Authors: Arne Ervik, Pia Kupka Hansen, Per Johannessen, Jan Aure, Anders Stigebrandt, Terje Jahnsen
    Abstract:

    Abstract The paper describes the concept of a management system called MOM (Modelling-Ongrowing Fish Farms-Monitoring) which may be used to adjust the local environmental impact of marine Fish Farms to the holding capacity of the sites. The concept is based on integrating the elements of environmental impact assessment, monitoring of impact and environmental quality standards (EQS) into one system. The amount of monitoring is dependent on the level of the environmental impact. Two terms are introduced: (1) the degree of exploitation, which is an expression of how much the site is being utilised, and (2) the level of monitoring, which determines the amount of monitoring depending on the environmental impact. For Norwegian conditions, a monitoring programme, including EQS, has been developed concerning the impact on the sediment under Fish Farms. It consists of three types of investigations of increasing elaboration and accuracy. A model, which simulates the environmental impact on a site given information about the farm's size and production and the hydrodynamic conditions and topography of the site, has been developed but not yet tested. The model and the monitoring programme with EQS are only briefly described, but will be published later. The MOM system should help to maintain satisfactory environmental conditions in and around Fish Farms and may be a valuable tool in site selection and coastal zone management.

Pia Kupka Hansen - One of the best experts on this subject based on the ideXlab platform.

  • regulating the local environmental impact of intensive marine Fish farming ii the monitoring programme of the mom system modelling ongrowing Fish Farms monitoring
    Aquaculture, 2001
    Co-Authors: Pia Kupka Hansen, Arne Ervik, Morten Schaanning, Per Johannessen, Jan Aure, Terje Jahnsen, Anders Stigebrandt
    Abstract:

    A programme for monitoring the impact of organic waste from marine Fish Farms is presented. . It consists of three types of investigation of increasing complexity and accuracy A, B and C , which are applied more frequently with increasing environmental impact. The A-investigation is a simple measurement of sedimentation rate beneath the net cages; the B-investigation is a sediment investigation providing a trend monitoring of the sediment condition, and the C-investigation is a comprehensive investigation of the benthic macrofaunal community structure. The A- and B-investigations were designed specifically for Fish farming and the latter utilises several parameters in order to make the investigation more robust. The C-investigation employs well- established methods and procedures, which have been used previously in monitoring programmes. . Environmental quality standards EQS have been set for the B- and C-investigation. The monitoring programme is part of a larger management system in Norway called Modelling- . Ongrowing Fish Farms-Monitoring MOM . q 2001 Elsevier Science B.V. All rights reserved.

  • regulating the local environmental impact of intensive marine Fish farming i the concept of the mom system modelling ongrowing Fish Farms monitoring
    Aquaculture, 1997
    Co-Authors: Arne Ervik, Pia Kupka Hansen, Per Johannessen, Jan Aure, Anders Stigebrandt, Terje Jahnsen
    Abstract:

    Abstract The paper describes the concept of a management system called MOM (Modelling-Ongrowing Fish Farms-Monitoring) which may be used to adjust the local environmental impact of marine Fish Farms to the holding capacity of the sites. The concept is based on integrating the elements of environmental impact assessment, monitoring of impact and environmental quality standards (EQS) into one system. The amount of monitoring is dependent on the level of the environmental impact. Two terms are introduced: (1) the degree of exploitation, which is an expression of how much the site is being utilised, and (2) the level of monitoring, which determines the amount of monitoring depending on the environmental impact. For Norwegian conditions, a monitoring programme, including EQS, has been developed concerning the impact on the sediment under Fish Farms. It consists of three types of investigations of increasing elaboration and accuracy. A model, which simulates the environmental impact on a site given information about the farm's size and production and the hydrodynamic conditions and topography of the site, has been developed but not yet tested. The model and the monitoring programme with EQS are only briefly described, but will be published later. The MOM system should help to maintain satisfactory environmental conditions in and around Fish Farms and may be a valuable tool in site selection and coastal zone management.