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Papers by Aleksander Handå

Research paper thumbnail of Incorporation of salmon fish feed and faeces components in mussels (Mytilus edulis): Implications for integrated multi-trophic aquaculture in cool-temperate North Atlantic waters

Research paper thumbnail of Chemical composition of feed, fish and faeces as input to mass balance estimation of biogeneic waste discharge from an Atlantic salmon farm with an evaluation of IMTA feasibility

Aquaculture Environment Interactions

Research paper thumbnail of 4409213 Prostanoid compounds and pharmaceutical compositions

Research paper thumbnail of Chemical composition and release rate of waste discharge from an Atlantic salmon farm with an evaluation of IMTA feasibility

Research paper thumbnail of The role of environmental biotechnology in exploring, exploiting, monitoring, preserving, protecting and decontaminating the marine environment

New Biotechnology, 2014

In light of the Marine Strategy Framework Directive (MSFD) and the EU Thematic Strategy on the Su... more In light of the Marine Strategy Framework Directive (MSFD) and the EU Thematic Strategy on the Sustainable Use of Natural Resources, environmental biotechnology could make significant contributions in the exploitation of marine resources and addressing key marine environmental problems. In this paper 14 propositions are presented focusing on (i) the contamination of the marine environment, and more particularly how to optimize the use of biotechnology-related tools and strategies for predicting and monitoring contamination and developing mitigation measures; (ii) the exploitation of the marine biological and genetic resources to progress with the sustainable, eco-compatible use of the maritime space (issues are very diversified and include, for example, waste treatment and recycling, anti-biofouling agents; bio-plastics); (iii) environmental/marine biotechnology as a driver for a sustainable economic growth.

Research paper thumbnail of Growth of farmed blue mussels (Mytilus edulis L.) in a Norwegian coastal area; comparison of food proxies by DEB modeling

Journal of Sea Research, 2011

Seston variables and growth of the blue mussel (Mytilus edulis L.) were measured during the growt... more Seston variables and growth of the blue mussel (Mytilus edulis L.) were measured during the growth season from March to October in three suspended longline farms in Central Norway; one in the inner part of Åfjorden (63° 56′ N, 10° 11′ E) and two in Inner and Outer Koet, respectively (63° 49′ N, 9° 42′ and 47′ E). Four seston

Research paper thumbnail of Development of Saccharina latissima (Phaeophyceae) kelp hatcheries with year-round production of zoospores and juvenile sporophytes on culture ropes for kelp aquaculture

Journal of Applied Phycology, 2012

ABSTRACT Saccharina latissima is attractive for industrial cultivation for different usages, such... more ABSTRACT Saccharina latissima is attractive for industrial cultivation for different usages, such as biofuels, feed supplements, and derivation of chemicals. A continuous supply of kelp sporelings throughout the year may ensure a year-round production of kelp juveniles on ropes. In this study, induction of sporangial areas (sorus portions) on the blade of S. latissima was performed throughout the year at three locations: Trondheim (Norway), Grenaa (Denmark), and Sylt island (Germany). The results indicate that a year-round sorus induction in S. latissima is possible and that this induction is controlled by applying short-day treatment of adult sporophytes throughout the year and by the removal of the basal blade meristem. The artificially induced and released zoospores formed viable sporelings at all seasons, but cultivation in the sea in Norway was successful only during autumn, winter, and spring, while the growth conditions were poor during the summer. The results are important for industrial scale-up and continuous production of kelp biomass.

Research paper thumbnail of Assimilation of inorganic nutrients from salmon (Salmo salar) farming by the macroalgae (Saccharina latissima) in an exposed coastal environment: implications for integrated multi-trophic aquaculture

Journal of Applied Phycology, 2013

Research paper thumbnail of Temperature-dependent feed requirements in farmed blue mussels ( Mytilus edulis L.) estimated from soft tissue growth and oxygen consumption and ammonia-N excretion

Aquaculture Research, 2013

... Aleksander Handå1,2, Trond Nordtug3, Stein Halstensen2, Anders Johny Olsen1, Kjell Inge Reita... more ... Aleksander Handå1,2, Trond Nordtug3, Stein Halstensen2, Anders Johny Olsen1, Kjell Inge Reitan2, Yngvar Olsen1 & Helge Reinertsen1 ... Standard metabolism corresponds to the minimum energy demand to cover basal metabolism, includ-ing minimum pumping activity, and ...

Research paper thumbnail of Seasonal- and depth-dependent growth of cultivated kelp (Saccharina latissima) in close proximity to salmon (Salmo salar) aquaculture in Norway

Research paper thumbnail of Incorporation of salmon fish feed and feces components in mussels (Mytilus edulis): Implications for integrated multi-trophic aquaculture in cool-temperate North Atlantic waters

Aquaculture, 2012

ABSTRACT The incorporation of salmon fish feed and feces components in the digestive gland, mantl... more ABSTRACT The incorporation of salmon fish feed and feces components in the digestive gland, mantle, and gill tissue of blue mussels (Mytilus edulis), and associated growth in shell length and soft tissue dry weight, were studied in a 28 day laboratory experiment. Mussels were fed mixed rations of either salmon fish feed and Rhodomonas baltica, salmon feces and R. baltica or mono rations of either a full or half ration of R. baltica. Feed rations were designed to supply a particulate organic carbon ration equal to ~ 5% of soft tissue carbon content ind− 1 day− 1.Significant changes in the fatty acid composition, which appointed that of the food profiles, were evident in the digestive gland and gill tissue (p < 0.05), whereas no changes were found in mantle tissue. For digestive gland data, a principal component analysis particularly identified the contribution of 18:1 (n − 9), 18:3 (n − 3), 18:2 (n − 6) and 20:1 (n − 9) and as being the single fatty acids most responsible for the difference between the various diets.A significant growth in length was found for mussels fed fish feed and R. baltica (p < 0.05), but not for mussels fed feces and R. baltica. The dry weight was significantly higher for mussels fed the full diet with R. baltica compared to the other diets, and significantly lower for mussels fed feces and R. baltica than fish feed and R. baltica at the end of the experiment (p < 0.05).A more pronounced incorporation of salmon feed compared to salmon feces components in mussel tissues suggested that mussels will utilize fish feed more efficiently than feces particles in an integrated aquaculture with salmon.

Research paper thumbnail of Incorporation of fish feed and growth of blue mussels (Mytilus edulis) in close proximity to salmon (Salmo salar) aquaculture: Implications for integrated multi-trophic aquaculture in Norwegian coastal waters

Aquaculture, 2012

ABSTRACT The incorporation of fish feed wastes in digestive gland and mantle tissue and average g... more ABSTRACT The incorporation of fish feed wastes in digestive gland and mantle tissue and average growth in length and standardized dry weight of soft tissue matter (DW′) of blue mussels (Mytilus edulis L.) were measured for one year (June 2010–June 2011) at three experimental stations in close proximity to a salmon (Salmo salar) farm at Tristein (63° 52′ N, 9° 37′ E) in Central Norway, with one on the west side (FW), one on the east side (FE) and one 100 m east of the farm (FE100), in addition to one reference station 4 km south of the farm.A principal component analysis of fatty acid profiles clearly demonstrated the incorporation of fatty acids from salmon fish feed in digestive gland and mantle tissue, identified by an increased content of 18:1 (n-9). The incorporation, and consequently the separation of mussels at stations close to the fish farm from mussels at the reference station, was more pronounced in February compared to August, while no clear differences were found in June.The growth in length correlated significantly to feed use at the fish farm (r = 0.89) and to the concentration of suspended particulate matter (SPM) (r = 0.53) in the autumn–winter period (Oct–Feb) (p < 0.05). The mussels at the reference station showed a significantly faster growth in length compared to the mussels at all stations at the fish farm during the summer, while mussels at the FW station grew faster than the mussels at the reference station during the spring (p < 0.05). The length growth was faster for mussels at the reference station than for mussels at the FW and FE100 stations (p < 0.05), while no significant differences were found between mussels at the reference and the FE stations for the entire year.The DW′ was significantly positively correlated to the feed use at the fish farm stations (r = 0.53) (p < 0.05), and the DW′ of mussels at stations at the fish farm was significantly higher compared to the DW′ of mussels at the reference station in five months during autumn and winter (p < 0.05). The results suggest that the combined production of mussels and salmon can be seen as a strategy to maintain a higher soft tissue content of mussels during autumn and winter. Quantification of the mussel's assimilation capacities of farm-derived wastes at realistic scale and under different environmental conditions is needed.

Research paper thumbnail of Evaluation of β-(1→3, 1→6)-glucans and High-M alginate used as immunostimulatory dietary supplement during first feeding and weaning of Atlantic cod (Gadus morhua L.)

Research paper thumbnail of Controlled artificial upwelling in a fjord to stimulate non-toxic algae

Aquacultural Engineering, 2010

ABSTRACT During the summer, primary production in the surface layers of some fjords depletes the ... more ABSTRACT During the summer, primary production in the surface layers of some fjords depletes the nutrients to the degree that some species of toxic algae can dominate. We describe field experiments employing a bubble curtain and a submerged freshwater outlet to lift significant amounts of nutrient-rich seawater to the light zone to provide an environment in which non-toxic algae can bloom. The motivation for the experiment is to provide a local region with stimulated growth of non-toxic phytoplankton and thereby creating a possibility for mussels to be cleansed from the effects of toxic algae.In the first experiment, a 100-m long bubble curtain, using three perforated pipes submerged to 40m depth, was operated in the Arnafjord, a side arm of Sognefjorden in western Norway. An air supply of 44Nm3 each minute lifted 65m3/s of deeper seawater to the upper layer with intense mixing during a period of 3 weeks. The mixed water flowed from the mixing region at depths from 5 to 15m. Within a few days, the mixture of nutrient-rich water covered most of the inner portion of Arnafjord.In the second experiment, the 40m deep, 26m3/s discharge of freshwater from the Jostedal hydropower plant to Gaupnefjord, another side arm of Sognefjorden, was manipulated to enhance the upwelling of seawater by using a diffuser plate. The increased entrainment of seawater to the buoyant plume led to an intrusion of the discharge into the compensation current at 5–10m depth and a longer residence time in the local fjord arm. The field experiment showed an entrainment of 117m3/s of nutrient-rich seawater to the rising plume compared with 140m3/s obtained in a small-scale laboratory simulation, implying a sub-optimal placement of the plate over the outlet plume. This, however, was still more energy-efficient than the bubble curtain. In both experiments (bubbles and freshwater discharge) the increased nutrient inputs to the light zone resulted in increased growth of phytoplankton with a relative reduction of toxic algae.

Research paper thumbnail of Artificial upwelling to stimulate growth of non-toxic algae in a habitat for mussel farming

Aquaculture Research, 2013

ABSTRACT Large-scale artificial upwelling was tested as a method to enhance the environmental con... more ABSTRACT Large-scale artificial upwelling was tested as a method to enhance the environmental conditions for the growth of non-toxic algae in a Norwegian fjord (61°0′N, 6°22′E). The experiment was designed to evaluate if nutrient-rich seawater, brought up from below the mixed zone of a strati-fied fjord to the euphotic zone by air bubbling, would stimulate the growth of non-toxic relative to toxic algae. Pumping 44 m 3 min À1 of air at 1 atm through a pipe diffuser submerged at 40 m depth formed a buoyancy flux that lifted 60 m 3 s À1 of deep water to the upper 17 m over a period of 21 days. The supply of silicate, inor-ganic nitrogen and phosphate to the upper 10 m in the fjord increased, and a significant increase in the biomass of non-toxic algae was observed. The upwelling gave an increased growth of the non-toxic dinoflagellates Ceratium furca and C. tripos. After termination of the experiment, the phyto-plankton biomass decreased significantly, whereas a distinct increase occurred in the relative biomass of the potentially toxic Dinophysis spp. The result is considered promising when it comes to creating controlled geographical areas with non-toxic food for mussel production.

Research paper thumbnail of Incorporation of salmon fish feed and faeces components in mussels (Mytilus edulis): Implications for integrated multi-trophic aquaculture in cool-temperate North Atlantic waters

Research paper thumbnail of Chemical composition of feed, fish and faeces as input to mass balance estimation of biogeneic waste discharge from an Atlantic salmon farm with an evaluation of IMTA feasibility

Aquaculture Environment Interactions

Research paper thumbnail of 4409213 Prostanoid compounds and pharmaceutical compositions

Research paper thumbnail of Chemical composition and release rate of waste discharge from an Atlantic salmon farm with an evaluation of IMTA feasibility

Research paper thumbnail of The role of environmental biotechnology in exploring, exploiting, monitoring, preserving, protecting and decontaminating the marine environment

New Biotechnology, 2014

In light of the Marine Strategy Framework Directive (MSFD) and the EU Thematic Strategy on the Su... more In light of the Marine Strategy Framework Directive (MSFD) and the EU Thematic Strategy on the Sustainable Use of Natural Resources, environmental biotechnology could make significant contributions in the exploitation of marine resources and addressing key marine environmental problems. In this paper 14 propositions are presented focusing on (i) the contamination of the marine environment, and more particularly how to optimize the use of biotechnology-related tools and strategies for predicting and monitoring contamination and developing mitigation measures; (ii) the exploitation of the marine biological and genetic resources to progress with the sustainable, eco-compatible use of the maritime space (issues are very diversified and include, for example, waste treatment and recycling, anti-biofouling agents; bio-plastics); (iii) environmental/marine biotechnology as a driver for a sustainable economic growth.

Research paper thumbnail of Growth of farmed blue mussels (Mytilus edulis L.) in a Norwegian coastal area; comparison of food proxies by DEB modeling

Journal of Sea Research, 2011

Seston variables and growth of the blue mussel (Mytilus edulis L.) were measured during the growt... more Seston variables and growth of the blue mussel (Mytilus edulis L.) were measured during the growth season from March to October in three suspended longline farms in Central Norway; one in the inner part of Åfjorden (63° 56′ N, 10° 11′ E) and two in Inner and Outer Koet, respectively (63° 49′ N, 9° 42′ and 47′ E). Four seston

Research paper thumbnail of Development of Saccharina latissima (Phaeophyceae) kelp hatcheries with year-round production of zoospores and juvenile sporophytes on culture ropes for kelp aquaculture

Journal of Applied Phycology, 2012

ABSTRACT Saccharina latissima is attractive for industrial cultivation for different usages, such... more ABSTRACT Saccharina latissima is attractive for industrial cultivation for different usages, such as biofuels, feed supplements, and derivation of chemicals. A continuous supply of kelp sporelings throughout the year may ensure a year-round production of kelp juveniles on ropes. In this study, induction of sporangial areas (sorus portions) on the blade of S. latissima was performed throughout the year at three locations: Trondheim (Norway), Grenaa (Denmark), and Sylt island (Germany). The results indicate that a year-round sorus induction in S. latissima is possible and that this induction is controlled by applying short-day treatment of adult sporophytes throughout the year and by the removal of the basal blade meristem. The artificially induced and released zoospores formed viable sporelings at all seasons, but cultivation in the sea in Norway was successful only during autumn, winter, and spring, while the growth conditions were poor during the summer. The results are important for industrial scale-up and continuous production of kelp biomass.

Research paper thumbnail of Assimilation of inorganic nutrients from salmon (Salmo salar) farming by the macroalgae (Saccharina latissima) in an exposed coastal environment: implications for integrated multi-trophic aquaculture

Journal of Applied Phycology, 2013

Research paper thumbnail of Temperature-dependent feed requirements in farmed blue mussels ( Mytilus edulis L.) estimated from soft tissue growth and oxygen consumption and ammonia-N excretion

Aquaculture Research, 2013

... Aleksander Handå1,2, Trond Nordtug3, Stein Halstensen2, Anders Johny Olsen1, Kjell Inge Reita... more ... Aleksander Handå1,2, Trond Nordtug3, Stein Halstensen2, Anders Johny Olsen1, Kjell Inge Reitan2, Yngvar Olsen1 & Helge Reinertsen1 ... Standard metabolism corresponds to the minimum energy demand to cover basal metabolism, includ-ing minimum pumping activity, and ...

Research paper thumbnail of Seasonal- and depth-dependent growth of cultivated kelp (Saccharina latissima) in close proximity to salmon (Salmo salar) aquaculture in Norway

Research paper thumbnail of Incorporation of salmon fish feed and feces components in mussels (Mytilus edulis): Implications for integrated multi-trophic aquaculture in cool-temperate North Atlantic waters

Aquaculture, 2012

ABSTRACT The incorporation of salmon fish feed and feces components in the digestive gland, mantl... more ABSTRACT The incorporation of salmon fish feed and feces components in the digestive gland, mantle, and gill tissue of blue mussels (Mytilus edulis), and associated growth in shell length and soft tissue dry weight, were studied in a 28 day laboratory experiment. Mussels were fed mixed rations of either salmon fish feed and Rhodomonas baltica, salmon feces and R. baltica or mono rations of either a full or half ration of R. baltica. Feed rations were designed to supply a particulate organic carbon ration equal to ~ 5% of soft tissue carbon content ind− 1 day− 1.Significant changes in the fatty acid composition, which appointed that of the food profiles, were evident in the digestive gland and gill tissue (p < 0.05), whereas no changes were found in mantle tissue. For digestive gland data, a principal component analysis particularly identified the contribution of 18:1 (n − 9), 18:3 (n − 3), 18:2 (n − 6) and 20:1 (n − 9) and as being the single fatty acids most responsible for the difference between the various diets.A significant growth in length was found for mussels fed fish feed and R. baltica (p < 0.05), but not for mussels fed feces and R. baltica. The dry weight was significantly higher for mussels fed the full diet with R. baltica compared to the other diets, and significantly lower for mussels fed feces and R. baltica than fish feed and R. baltica at the end of the experiment (p < 0.05).A more pronounced incorporation of salmon feed compared to salmon feces components in mussel tissues suggested that mussels will utilize fish feed more efficiently than feces particles in an integrated aquaculture with salmon.

Research paper thumbnail of Incorporation of fish feed and growth of blue mussels (Mytilus edulis) in close proximity to salmon (Salmo salar) aquaculture: Implications for integrated multi-trophic aquaculture in Norwegian coastal waters

Aquaculture, 2012

ABSTRACT The incorporation of fish feed wastes in digestive gland and mantle tissue and average g... more ABSTRACT The incorporation of fish feed wastes in digestive gland and mantle tissue and average growth in length and standardized dry weight of soft tissue matter (DW′) of blue mussels (Mytilus edulis L.) were measured for one year (June 2010–June 2011) at three experimental stations in close proximity to a salmon (Salmo salar) farm at Tristein (63° 52′ N, 9° 37′ E) in Central Norway, with one on the west side (FW), one on the east side (FE) and one 100 m east of the farm (FE100), in addition to one reference station 4 km south of the farm.A principal component analysis of fatty acid profiles clearly demonstrated the incorporation of fatty acids from salmon fish feed in digestive gland and mantle tissue, identified by an increased content of 18:1 (n-9). The incorporation, and consequently the separation of mussels at stations close to the fish farm from mussels at the reference station, was more pronounced in February compared to August, while no clear differences were found in June.The growth in length correlated significantly to feed use at the fish farm (r = 0.89) and to the concentration of suspended particulate matter (SPM) (r = 0.53) in the autumn–winter period (Oct–Feb) (p < 0.05). The mussels at the reference station showed a significantly faster growth in length compared to the mussels at all stations at the fish farm during the summer, while mussels at the FW station grew faster than the mussels at the reference station during the spring (p < 0.05). The length growth was faster for mussels at the reference station than for mussels at the FW and FE100 stations (p < 0.05), while no significant differences were found between mussels at the reference and the FE stations for the entire year.The DW′ was significantly positively correlated to the feed use at the fish farm stations (r = 0.53) (p < 0.05), and the DW′ of mussels at stations at the fish farm was significantly higher compared to the DW′ of mussels at the reference station in five months during autumn and winter (p < 0.05). The results suggest that the combined production of mussels and salmon can be seen as a strategy to maintain a higher soft tissue content of mussels during autumn and winter. Quantification of the mussel's assimilation capacities of farm-derived wastes at realistic scale and under different environmental conditions is needed.

Research paper thumbnail of Evaluation of β-(1→3, 1→6)-glucans and High-M alginate used as immunostimulatory dietary supplement during first feeding and weaning of Atlantic cod (Gadus morhua L.)

Research paper thumbnail of Controlled artificial upwelling in a fjord to stimulate non-toxic algae

Aquacultural Engineering, 2010

ABSTRACT During the summer, primary production in the surface layers of some fjords depletes the ... more ABSTRACT During the summer, primary production in the surface layers of some fjords depletes the nutrients to the degree that some species of toxic algae can dominate. We describe field experiments employing a bubble curtain and a submerged freshwater outlet to lift significant amounts of nutrient-rich seawater to the light zone to provide an environment in which non-toxic algae can bloom. The motivation for the experiment is to provide a local region with stimulated growth of non-toxic phytoplankton and thereby creating a possibility for mussels to be cleansed from the effects of toxic algae.In the first experiment, a 100-m long bubble curtain, using three perforated pipes submerged to 40m depth, was operated in the Arnafjord, a side arm of Sognefjorden in western Norway. An air supply of 44Nm3 each minute lifted 65m3/s of deeper seawater to the upper layer with intense mixing during a period of 3 weeks. The mixed water flowed from the mixing region at depths from 5 to 15m. Within a few days, the mixture of nutrient-rich water covered most of the inner portion of Arnafjord.In the second experiment, the 40m deep, 26m3/s discharge of freshwater from the Jostedal hydropower plant to Gaupnefjord, another side arm of Sognefjorden, was manipulated to enhance the upwelling of seawater by using a diffuser plate. The increased entrainment of seawater to the buoyant plume led to an intrusion of the discharge into the compensation current at 5–10m depth and a longer residence time in the local fjord arm. The field experiment showed an entrainment of 117m3/s of nutrient-rich seawater to the rising plume compared with 140m3/s obtained in a small-scale laboratory simulation, implying a sub-optimal placement of the plate over the outlet plume. This, however, was still more energy-efficient than the bubble curtain. In both experiments (bubbles and freshwater discharge) the increased nutrient inputs to the light zone resulted in increased growth of phytoplankton with a relative reduction of toxic algae.

Research paper thumbnail of Artificial upwelling to stimulate growth of non-toxic algae in a habitat for mussel farming

Aquaculture Research, 2013

ABSTRACT Large-scale artificial upwelling was tested as a method to enhance the environmental con... more ABSTRACT Large-scale artificial upwelling was tested as a method to enhance the environmental conditions for the growth of non-toxic algae in a Norwegian fjord (61°0′N, 6°22′E). The experiment was designed to evaluate if nutrient-rich seawater, brought up from below the mixed zone of a strati-fied fjord to the euphotic zone by air bubbling, would stimulate the growth of non-toxic relative to toxic algae. Pumping 44 m 3 min À1 of air at 1 atm through a pipe diffuser submerged at 40 m depth formed a buoyancy flux that lifted 60 m 3 s À1 of deep water to the upper 17 m over a period of 21 days. The supply of silicate, inor-ganic nitrogen and phosphate to the upper 10 m in the fjord increased, and a significant increase in the biomass of non-toxic algae was observed. The upwelling gave an increased growth of the non-toxic dinoflagellates Ceratium furca and C. tripos. After termination of the experiment, the phyto-plankton biomass decreased significantly, whereas a distinct increase occurred in the relative biomass of the potentially toxic Dinophysis spp. The result is considered promising when it comes to creating controlled geographical areas with non-toxic food for mussel production.