Parasites generate costs for managing infections as well as prophylactic treatment in finfish aqu... more Parasites generate costs for managing infections as well as prophylactic treatment in finfish aquaculture. Based on estimated hatchery losses to parasitism of 20%, the authors estimated annual global loss of juvenile fish to parasites at U.S. $107.31 million to $134.14 million. Assuming parasites are responsible for losses of 1% to 10% of harvest-size fish, the value of these fish was estimated at $945.00 million to $9.45 billion. Combining the hatchery and growout figures, the parasites’ annual cost was tentatively estimated at $1.05 billion to $9.58 billion
Abstract With growing world trends in the consumption of raw and undercooked aquatic products, an... more Abstract With growing world trends in the consumption of raw and undercooked aquatic products, anisakiasis, resulting from infection by anisakid nematodes, currently affects over 2000 people per annum worldwide. In response to new EC regulatory requirements regarding the processing of farmed fish to reduce the risk of nematode infections, the aim of this study was to provide evidence of the prevalence and intensity of anisakids in relevant Scottish mariculture species and to identify potential probability of nematode infection by analysing the current farming practices for these species. A sample of 225 marine rainbow trout, Oncorhynchus mykiss , and 150 Atlantic halibut, Hippoglossus hippoglossus , was obtained from three and two farms, respectively, on the West Coast of Scotland. A further 12 Atlantic halibut were obtained from wild fisheries. Fish flesh examined for nematode larvae using standard techniques provided no evidence for the presence of anisakid nematodes in any of the farmed fish sampled. In addition, no food items other than pelleted feed were found in the stomach and intestines of any farmed fish. Sampled wild halibut showed a prevalence of 75% and intensity of 12.75 ± 25.81 of Anisakis simplex although no Pseudoterranova decipiens were found. An analysis of current farm practices for the culture of halibut, rainbow trout and sea trout, Salmo trutta , in Scotland suggests that the probability of infection with anisakids is extremely low. To acquire an infection, a fish must consume infected prey, and as commercial aquaculture in Scotland relies on processed, pelleted feed, the probability of wild infected prey being consumed is very low, particularly since fish are generally fed to satiation. Given the results of this study and evidence from previous studies, it must be concluded that under current farming practices, the risk of contracting anisakiasis from Scottish farmed halibut and rainbow trout is extremely low to negligible. Consequently, they do not pose a significant risk to consumers in terms of the ingestion of these parasites.
This review concerns the parasitic marine copepod Lernaeocera branchialis (L., 1767) and provides... more This review concerns the parasitic marine copepod Lernaeocera branchialis (L., 1767) and provides an overview of current knowledge concerning its biology and host-parasite interactions. The large size and distinctive appearance of the metamorphosed adult female stage, coupled with the wide exploitation and commercial importance of its final gadoid hosts, means that this species has long been recognised in the scientific literature. The fact that the Atlantic cod, Gadus morhua L., is one of its key host species, and has itself had a major impact on the social and economic development of many countries bordering the North Atlantic for more than 10 centuries is also a factor in its widespread recognition. L. branchialis is recognised as a pathogen that could have major effects on the aquaculture industry and with gadoid (especially cod) farming expanding in several North Atlantic countries, there is considerable potential for this parasite to become a serious problem for commercial mariculture. The main subject areas covered are the parasite's taxonomy; the life history of the parasite including its life cycle, reproduction and host associations; parasite physiology; parasite seasonality and distribution; and the pathogenic effects of the parasite on its host.
Abstract There is a growing movement to involve young people in decision making for the marine en... more Abstract There is a growing movement to involve young people in decision making for the marine environment, with a wider trend towards public participation and greater accountability of environmental governance. Young people will inherit the consequences of decisions made today. In this paper, the authors provide an initial exploration of young people’s views, awareness and participation (current and potential) in decisions and strategies for the marine environment, using Scotland as a case study. These discussions are based on the results of a survey of young people (aged 11–26) in Scotland, appraising levels of understanding and engagement with marine issues and exploring barriers to and opportunities for improved participation. This is set in the context of (a) the growth of local, national and global platforms for young people to express their views, and (b) the aspiration of many governments to empower the public, communities and young people in public decision making and marine stewardship. Education and ocean-literacy initiatives have a role to play, but there is also an aspiration for engagement mechanisms that accelerate a more fundamental rebalancing in public process to safeguard environmental integrity (and therefore economic and social well-being) for future generations. The authors conclude that marine planning, specifically the development of regional marine plans in Scotland, can provide a mechanism to integrate young people’s views and needs into marine decision making.
Current sea louse models attempt to estimate louse burdens on wild and cultured salmon by predict... more Current sea louse models attempt to estimate louse burdens on wild and cultured salmon by predicting the production and distribution of lice larvae and estimating the risk of transmission. While physical characteristics of water bodies and weather can be accurately modelled, many aspects of sea lice biology require further parameterization. The aims of this review are (i) to describe current knowledge regarding the production, mortality, and infectivity of planktonic sea lice larvae and (ii) to identify gaps in knowledge and suggest research approaches to filling them. Several major gaps are identified, and those likely to have the greatest impact on infection levels are (i) egg production, viability and hatching success, (ii) predation in plankton and (iii) copepodid infectivity profiles. A key problem identified in current parameter estimates is that they originate from a number of sources and have been determined using a variety of experimental approaches. This is a barrier to th...
Background: The high transmission potential of species belonging to the monogenean parasite genus... more Background: The high transmission potential of species belonging to the monogenean parasite genus Gyrodactylus, coupled with their high fecundity, allows them to rapidly colonise new hosts and to increase in number. One gyrodactylid, Gyrodactylus salaris Malmberg, 1957, has been responsible for devastation of Altantic salmon (Salmo salar L.) populations in a number of Norwegian rivers. Current methods of eradicating G. salaris from river systems centre around the use of non-specific biocides, such as rotenone and aluminium sulphate. Although transmission routes in gyrodactylids have been studied extensively, the behaviour of individual parasites has received little attention. Specimens of Gyrodactylus gasterostei Gläser, 1974 and G. arcuatus Bychowsky, 1933, were collected from the skin of their host, the three-spined stickleback (Gasterosteus aculeatus L.), and permitted to attach to the substrate. The movements of individual parasites were recorded and analysed. Results: The behav...
Parasites generate costs for managing infections as well as prophylactic treatment in finfish aqu... more Parasites generate costs for managing infections as well as prophylactic treatment in finfish aquaculture. Based on estimated hatchery losses to parasitism of 20%, the authors estimated annual global loss of juvenile fish to parasites at U.S. $107.31 million to $134.14 million. Assuming parasites are responsible for losses of 1% to 10% of harvest-size fish, the value of these fish was estimated at $945.00 million to $9.45 billion. Combining the hatchery and growout figures, the parasites’ annual cost was tentatively estimated at $1.05 billion to $9.58 billion
Parasites generate costs for managing infections as well as prophylactic treatment in finfish aqu... more Parasites generate costs for managing infections as well as prophylactic treatment in finfish aquaculture. Based on estimated hatchery losses to parasitism of 20%, the authors estimated annual global loss of juvenile fish to parasites at U.S. $107.31 million to $134.14 million. Assuming parasites are responsible for losses of 1% to 10% of harvest-size fish, the value of these fish was estimated at $945.00 million to $9.45 billion. Combining the hatchery and growout figures, the parasites’ annual cost was tentatively estimated at $1.05 billion to $9.58 billion
Abstract With growing world trends in the consumption of raw and undercooked aquatic products, an... more Abstract With growing world trends in the consumption of raw and undercooked aquatic products, anisakiasis, resulting from infection by anisakid nematodes, currently affects over 2000 people per annum worldwide. In response to new EC regulatory requirements regarding the processing of farmed fish to reduce the risk of nematode infections, the aim of this study was to provide evidence of the prevalence and intensity of anisakids in relevant Scottish mariculture species and to identify potential probability of nematode infection by analysing the current farming practices for these species. A sample of 225 marine rainbow trout, Oncorhynchus mykiss , and 150 Atlantic halibut, Hippoglossus hippoglossus , was obtained from three and two farms, respectively, on the West Coast of Scotland. A further 12 Atlantic halibut were obtained from wild fisheries. Fish flesh examined for nematode larvae using standard techniques provided no evidence for the presence of anisakid nematodes in any of the farmed fish sampled. In addition, no food items other than pelleted feed were found in the stomach and intestines of any farmed fish. Sampled wild halibut showed a prevalence of 75% and intensity of 12.75 ± 25.81 of Anisakis simplex although no Pseudoterranova decipiens were found. An analysis of current farm practices for the culture of halibut, rainbow trout and sea trout, Salmo trutta , in Scotland suggests that the probability of infection with anisakids is extremely low. To acquire an infection, a fish must consume infected prey, and as commercial aquaculture in Scotland relies on processed, pelleted feed, the probability of wild infected prey being consumed is very low, particularly since fish are generally fed to satiation. Given the results of this study and evidence from previous studies, it must be concluded that under current farming practices, the risk of contracting anisakiasis from Scottish farmed halibut and rainbow trout is extremely low to negligible. Consequently, they do not pose a significant risk to consumers in terms of the ingestion of these parasites.
This review concerns the parasitic marine copepod Lernaeocera branchialis (L., 1767) and provides... more This review concerns the parasitic marine copepod Lernaeocera branchialis (L., 1767) and provides an overview of current knowledge concerning its biology and host-parasite interactions. The large size and distinctive appearance of the metamorphosed adult female stage, coupled with the wide exploitation and commercial importance of its final gadoid hosts, means that this species has long been recognised in the scientific literature. The fact that the Atlantic cod, Gadus morhua L., is one of its key host species, and has itself had a major impact on the social and economic development of many countries bordering the North Atlantic for more than 10 centuries is also a factor in its widespread recognition. L. branchialis is recognised as a pathogen that could have major effects on the aquaculture industry and with gadoid (especially cod) farming expanding in several North Atlantic countries, there is considerable potential for this parasite to become a serious problem for commercial mariculture. The main subject areas covered are the parasite's taxonomy; the life history of the parasite including its life cycle, reproduction and host associations; parasite physiology; parasite seasonality and distribution; and the pathogenic effects of the parasite on its host.
Abstract There is a growing movement to involve young people in decision making for the marine en... more Abstract There is a growing movement to involve young people in decision making for the marine environment, with a wider trend towards public participation and greater accountability of environmental governance. Young people will inherit the consequences of decisions made today. In this paper, the authors provide an initial exploration of young people’s views, awareness and participation (current and potential) in decisions and strategies for the marine environment, using Scotland as a case study. These discussions are based on the results of a survey of young people (aged 11–26) in Scotland, appraising levels of understanding and engagement with marine issues and exploring barriers to and opportunities for improved participation. This is set in the context of (a) the growth of local, national and global platforms for young people to express their views, and (b) the aspiration of many governments to empower the public, communities and young people in public decision making and marine stewardship. Education and ocean-literacy initiatives have a role to play, but there is also an aspiration for engagement mechanisms that accelerate a more fundamental rebalancing in public process to safeguard environmental integrity (and therefore economic and social well-being) for future generations. The authors conclude that marine planning, specifically the development of regional marine plans in Scotland, can provide a mechanism to integrate young people’s views and needs into marine decision making.
Current sea louse models attempt to estimate louse burdens on wild and cultured salmon by predict... more Current sea louse models attempt to estimate louse burdens on wild and cultured salmon by predicting the production and distribution of lice larvae and estimating the risk of transmission. While physical characteristics of water bodies and weather can be accurately modelled, many aspects of sea lice biology require further parameterization. The aims of this review are (i) to describe current knowledge regarding the production, mortality, and infectivity of planktonic sea lice larvae and (ii) to identify gaps in knowledge and suggest research approaches to filling them. Several major gaps are identified, and those likely to have the greatest impact on infection levels are (i) egg production, viability and hatching success, (ii) predation in plankton and (iii) copepodid infectivity profiles. A key problem identified in current parameter estimates is that they originate from a number of sources and have been determined using a variety of experimental approaches. This is a barrier to th...
Background: The high transmission potential of species belonging to the monogenean parasite genus... more Background: The high transmission potential of species belonging to the monogenean parasite genus Gyrodactylus, coupled with their high fecundity, allows them to rapidly colonise new hosts and to increase in number. One gyrodactylid, Gyrodactylus salaris Malmberg, 1957, has been responsible for devastation of Altantic salmon (Salmo salar L.) populations in a number of Norwegian rivers. Current methods of eradicating G. salaris from river systems centre around the use of non-specific biocides, such as rotenone and aluminium sulphate. Although transmission routes in gyrodactylids have been studied extensively, the behaviour of individual parasites has received little attention. Specimens of Gyrodactylus gasterostei Gläser, 1974 and G. arcuatus Bychowsky, 1933, were collected from the skin of their host, the three-spined stickleback (Gasterosteus aculeatus L.), and permitted to attach to the substrate. The movements of individual parasites were recorded and analysed. Results: The behav...
Parasites generate costs for managing infections as well as prophylactic treatment in finfish aqu... more Parasites generate costs for managing infections as well as prophylactic treatment in finfish aquaculture. Based on estimated hatchery losses to parasitism of 20%, the authors estimated annual global loss of juvenile fish to parasites at U.S. $107.31 million to $134.14 million. Assuming parasites are responsible for losses of 1% to 10% of harvest-size fish, the value of these fish was estimated at $945.00 million to $9.45 billion. Combining the hatchery and growout figures, the parasites’ annual cost was tentatively estimated at $1.05 billion to $9.58 billion
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