Adam Brooker - Academia.edu (original) (raw)

Papers by Adam Brooker

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. 107.31millionto107.31 million to 107.31millionto134.14 million. Assuming parasites are responsible for losses of 1% to 10% of harvest-size fish, the value of these fish was estimated at 945.00millionto945.00 million to 945.00millionto9.45 billion. Combining the hatchery and growout figures, the parasites’ annual cost was tentatively estimated at 1.05billionto1.05 billion to 1.05billionto9.58 billion

Food Control, Aug 1, 2016

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.

I would like to express my gratitude to my supervisors Andy Shinn and James Bron for their contin... more I would like to express my gratitude to my supervisors Andy Shinn and James Bron for their continuous support and guidance throughout my PhD. My passage through the PhD minefield was facilitated by Andy's optimism and enthusiasm, and James' good humour and critical eye, which helped me to achieve the high standard required. I would also like to thank James for the endless hours spent with me working on the confocal microscope and the statistical analysis of parasite behaviour data. Thanks to the Natural Environment Research Council for providing me with funding throughout the project, giving me the opportunity to work in the field of parasitology. Thanks to the staff at Longannet power station and Willie McBrien, the shrimp boat man, for providing me with enough infected fish for my experiments whenever I required them, and often at short notice. Thanks to the staff at the Institute of Aquaculture, especially Rob Aitken for use of the marine aquarium facility, Ian Elliot for use of the teaching lab and equipment, Linton Brown for guidance and use of the SEM and Denny Conway for assistance with digital photography and putting up with me in the lab! I would like to thank all my friends in the Parasitology group and Institute of Aquaculture, for creating a relaxed and friendly atmosphere, in which working is always a pleasure. Also thanks to Lisa Summers for always being there throughout the good and the bad times. Many thanks to my fishing buddies, Rob McKeown, Pat Reynolds and Mark Burns, for dragging me away from the lab when I needed a break and the many hours of good company and whisky drinking spent relaxing by the water's edge. Last, but not least, I would like to thank my parents for their unconditional love and support, both emotionally and financially. II Declaration I declare that this thesis has been compiled by myself and is the result of my own investigations. It has not been submitted for any other degree and all sources of information have been duly acknowledged.

Aquatic Biology, Jan 4, 2012

The last detailed morphological descriptions of the juvenile stages of the parasitic copepod Lern... more The last detailed morphological descriptions of the juvenile stages of the parasitic copepod Lernaeocera branchialis (L., 1767) were written more than 70 yr ago, since which time both taxonomic nomenclature and available imaging technologies have changed substantially. In this paper a re-description of the free-swimming juvenile stages of L. branchialis is presented using a combination of traditional light microscopy and modern laser scanning confocal microscopy (LSCM) techniques. Detailed descriptions are provided of the nauplius I, nauplius II and copepodid stages and comparisons are made with the findings for other siphonostomatoids. Nauplius II is previously undescribed and several structures are described at the terminal tip which have not been found in other pennellids. With renewed interest in L. branchialis as a result of expanding gadoid aquaculture in North Atlantic countries, this re-description provides important information on its life history that may be useful for further research into this potentially devastating pathogen.

Parasitology, Feb 1, 2013

The life cycle of the parasitic copepod Lernaeocera branchialis involves 2 hosts, typically a ple... more The life cycle of the parasitic copepod Lernaeocera branchialis involves 2 hosts, typically a pleuronectiform host upon which development of larvae and mating of adults occurs and a subsequent gadoid host, upon which the adult female feeds and reproduces. Both the copepodid and adult female stages must therefore locate and identify a suitable host to continue the life cycle. Several mechanisms are potentially involved in locating a host and ensuring its suitability for infection. These may include mechano-reception to detect host movement and chemo-reception to recognize host-associated chemical cues, or kairomones. The aim of this study was to identify the role of kairomones in host location by adult L. branchialis, by analysing their behaviour in response to fish-derived chemicals. Experiments demonstrated that water conditioned by immersion of whiting, Merlangius merlangus, elicited host-seeking behaviour in L. branchialis, whereas cod-(Gadus morhua) conditioned water did not. Lernaeocera branchialis are considered a genetically homogeneous population infecting a range of gadoids. However, their differential response to whiting-and cod-derived chemicals in this study suggests that either there are genetically determined subspecies of L. branchialis or there is some form of environmental pre-conditioning that allows the parasite to preferentially recognize the host species from which it originated.

Elsevier eBooks, 2007

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.

Aquaculture, Aug 1, 2006

Modern Geographical Information Systems (GIS) offer a powerful modelling environment capable of h... more Modern Geographical Information Systems (GIS) offer a powerful modelling environment capable of handling large databases. They are a very suitable environment in which to develop a suite of tools designed for environmental management of aquaculture sites, including carrying capacity prediction, land-water interactions and multi-site effects. One such tool, presented here, is a fully integrated and validated particulate fish waste dispersion module which uses mass balance to estimate waste input and takes account of variable bathymetry and variable settling velocity for feed and faecal components. The model also incorporates the effect of cage movement on waste dispersion, the first such model to do so. When tidal range was low (1.67m), the maximum movement of a 22m diameter circular cage was 10.1m and 7.7m easting and northing respectively. Highest deposition from particulate fish waste is under the cage and incorporation of cage movement increased the effective area under a cage by 72%. This reduced peak deposition measurements by up to 32% and reduced the average modelled feed and faecal settlement at the cage centre by 23% and 11% respectively. The model was validated by comparing model predictions with observed deposition measured using sediment traps during three 2-week field trips at a fish farm on the west coast of Scotland. The mean ratio of observed to predicted waste deposition at 5-25m from the cage centre ranged from 0.9 to 1.06, whilst under the cage the model overpredicts deposition (observed/predicted = 2.21). Although far-field data was seen to be comparable the near-field discrepancies resulted in variable overall accuracy in the model. The overall accuracy based on August 2001 data was ± 50.9%, on February 2002 ± 72.8% and on April 2002 ± 50.6%. Summarizing the data resulted in an overall average predictive accuracy of ± 58.1%.

Ices Journal of Marine Science, Feb 19, 2018

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 the provision of "best" or consensus estimates for use in modelling. Additional and more consistent data collection and experimentation will help to fill these gaps. Furthermore, coordinated international efforts are required to generate a more complete picture of sea louse infections across all regions experiencing problems with sea lice.

한국수산과학회 양식분과 학술대회, May 1, 2015

Marine Policy, Feb 1, 2021

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.

Parasites & Vectors, Oct 27, 2011

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 behaviour patterns of the two species were similar and parasites were more active in red light and darkness than in white light. Four octopaminergic compounds were tested and all four inhibited the movements of parasites. Treatment ultimately led to death at low concentrations (0.2 μM), although prolonged exposure was necessary in some instances. Conclusions: Octopaminergic compounds may affect the parasite's ability to locate and remain on its host and these or related compounds might provide alternative or supplementary treatments for the control of G. salaris infections. With more research there is potential for use of octopaminergic compounds, which have minimal effects on the host or its environment, as parasite-specific treatments against G. salaris infections.

Aquatic Biology, Jan 4, 2012

The use of laser scanning confocal microscopy (LSCM) for creating taxonomic descriptions of copep... more The use of laser scanning confocal microscopy (LSCM) for creating taxonomic descriptions of copepods is investigated. A new technique is described, which employs a contour filter to process digital LSCM images, allowing taxonomic information to be quickly and accurately distilled into a simple illustration. LSCM allows the imaging of whole specimens, which can be rotated and viewed from any angle-a major benefit over light microscopy. Using this technique, it is suggested that taxonomic descriptions can be rapidly produced in a fraction of the time required to produce similar descriptions using traditional light microscopy and hand drawing techniques. Good staining of specimens is, however, essential to produce accurate descriptions and more research is required in this area. The use of LSCM for morphological taxonomy shows great potential, not only for producing taxonomic descriptions, but also providing a complementary adjunct to traditional type specimens in the form of 3D digital 'e-types' deposited in recognised international databases.

I would like to express my gratitude to my supervisors Andy Shinn and James Bron for their contin... more I would like to express my gratitude to my supervisors Andy Shinn and James Bron for their continuous support and guidance throughout my PhD. My passage through the PhD minefield was facilitated by Andy's optimism and enthusiasm, and James' good humour and critical eye, which helped me to achieve the high standard required. I would also like to thank James for the endless hours spent with me working on the confocal microscope and the statistical analysis of parasite behaviour data. Thanks to the Natural Environment Research Council for providing me with funding throughout the project, giving me the opportunity to work in the field of parasitology. Thanks to the staff at Longannet power station and Willie McBrien, the shrimp boat man, for providing me with enough infected fish for my experiments whenever I required them, and often at short notice. Thanks to the staff at the Institute of Aquaculture, especially Rob Aitken for use of the marine aquarium facility, Ian Elliot for use of the teaching lab and equipment, Linton Brown for guidance and use of the SEM and Denny Conway for assistance with digital photography and putting up with me in the lab! I would like to thank all my friends in the Parasitology group and Institute of Aquaculture, for creating a relaxed and friendly atmosphere, in which working is always a pleasure. Also thanks to Lisa Summers for always being there throughout the good and the bad times. Many thanks to my fishing buddies, Rob McKeown, Pat Reynolds and Mark Burns, for dragging me away from the lab when I needed a break and the many hours of good company and whisky drinking spent relaxing by the water's edge. Last, but not least, I would like to thank my parents for their unconditional love and support, both emotionally and financially. II Declaration I declare that this thesis has been compiled by myself and is the result of my own investigations. It has not been submitted for any other degree and all sources of information have been duly acknowledged.

Aquaculture, 2006

Modern Geographical Information Systems (GIS) offer a powerful modelling environment capable of h... more Modern Geographical Information Systems (GIS) offer a powerful modelling environment capable of handling large databases. They are a very suitable environment in which to develop a suite of tools designed for environmental management of aquaculture sites, including carrying capacity prediction, land-water interactions and multi-site effects. One such tool, presented here, is a fully integrated and validated particulate fish waste dispersion module which uses mass balance to estimate waste input and takes account of variable bathymetry and variable settling velocity for feed and faecal components. The model also incorporates the effect of cage movement on waste dispersion, the first such model to do so. When tidal range was low (1.67m), the maximum movement of a 22m diameter circular cage was 10.1m and 7.7m easting and northing respectively. Highest deposition from particulate fish waste is under the cage and incorporation of cage movement increased the effective area under a cage by 72%. This reduced peak deposition measurements by up to 32% and reduced the average modelled feed and faecal settlement at the cage centre by 23% and 11% respectively. The model was validated by comparing model predictions with observed deposition measured using sediment traps during three 2-week field trips at a fish farm on the west coast of Scotland. The mean ratio of observed to predicted waste deposition at 5-25m from the cage centre ranged from 0.9 to 1.06, whilst under the cage the model overpredicts deposition (observed/predicted = 2.21). Although far-field data was seen to be comparable the near-field discrepancies resulted in variable overall accuracy in the model. The overall accuracy based on August 2001 data was ± 50.9%, on February 2002 ± 72.8% and on April 2002 ± 50.6%. Summarizing the data resulted in an overall average predictive accuracy of ± 58.1%.

ICES Journal of Marine Science, 2018

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. 107.31millionto107.31 million to 107.31millionto134.14 million. Assuming parasites are responsible for losses of 1% to 10% of harvest-size fish, the value of these fish was estimated at 945.00millionto945.00 million to 945.00millionto9.45 billion. Combining the hatchery and growout figures, the parasites’ annual cost was tentatively estimated at 1.05billionto1.05 billion to 1.05billionto9.58 billion

Nematodes, also known as roundworms, are found in a wide range of aquatic and terrestrial habitat... more Nematodes, also known as roundworms, are found in a wide range of aquatic and terrestrial habitats, with over half of the known species being parasitic. Anisakid nematodes, which are commonly found in sea fish, are of particular importance as they are able to infect humans. The natural hosts of anisakids are whales and seals, but humans can become infected when raw or undercooked fish (e.g. cured or smoked) is eaten. Symptoms of anisakid infection (anisakiasis) often include nausea, stomach pain and vomiting. On rare occasions anisakid infection of humans can be fatal. With growing trends in the consumption of raw and undercooked fish, anisakiasis currently affects over 2000 people per annum worldwide, with 95% of cases located in Japan. In order to kill any anisakids present in fish, it must be either frozen or sufficiently cooked. However, even if there are no live anisakids, chemicals that they produce can still be present in fish flesh, which can cause allergic reactions in some people. An amendment in December 2011 of Annex III to Regulation (EC) No 853/2004, which concerns "treatment to kill viable parasites in fishery products for human consumption" permits that farmed fish do not need to be frozen to kill anisakids when intended to be marketed in a raw state (or is not intended to undergo a treatment that will kill viable parasites), where it can be proven that fish have been reared in an environment free of infection, or that adequate monitoring programmes are in place to verify that fishery products do not represent a health hazard with regards to anisakid worms. Although it is not possible to reduce anisakid infections in wild fish, in aquaculture, there is greater control over fish stocks so it is possible to prevent exposure to sources of nematode infection and to monitor infection levels to ensure that the fish are free from parasites. Previous research has shown that farmed Atlantic salmon in Scotland are free of anisakid infections. This study aims to analyse current farming practices for other Scottish mariculture species (Atlantic halibut, rainbow trout and sea trout) in order to identify potential sources / risks of anisakid infection, and to

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. 107.31millionto107.31 million to 107.31millionto134.14 million. Assuming parasites are responsible for losses of 1% to 10% of harvest-size fish, the value of these fish was estimated at 945.00millionto945.00 million to 945.00millionto9.45 billion. Combining the hatchery and growout figures, the parasites’ annual cost was tentatively estimated at 1.05billionto1.05 billion to 1.05billionto9.58 billion

Food Control, Aug 1, 2016

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.

I would like to express my gratitude to my supervisors Andy Shinn and James Bron for their contin... more I would like to express my gratitude to my supervisors Andy Shinn and James Bron for their continuous support and guidance throughout my PhD. My passage through the PhD minefield was facilitated by Andy's optimism and enthusiasm, and James' good humour and critical eye, which helped me to achieve the high standard required. I would also like to thank James for the endless hours spent with me working on the confocal microscope and the statistical analysis of parasite behaviour data. Thanks to the Natural Environment Research Council for providing me with funding throughout the project, giving me the opportunity to work in the field of parasitology. Thanks to the staff at Longannet power station and Willie McBrien, the shrimp boat man, for providing me with enough infected fish for my experiments whenever I required them, and often at short notice. Thanks to the staff at the Institute of Aquaculture, especially Rob Aitken for use of the marine aquarium facility, Ian Elliot for use of the teaching lab and equipment, Linton Brown for guidance and use of the SEM and Denny Conway for assistance with digital photography and putting up with me in the lab! I would like to thank all my friends in the Parasitology group and Institute of Aquaculture, for creating a relaxed and friendly atmosphere, in which working is always a pleasure. Also thanks to Lisa Summers for always being there throughout the good and the bad times. Many thanks to my fishing buddies, Rob McKeown, Pat Reynolds and Mark Burns, for dragging me away from the lab when I needed a break and the many hours of good company and whisky drinking spent relaxing by the water's edge. Last, but not least, I would like to thank my parents for their unconditional love and support, both emotionally and financially. II Declaration I declare that this thesis has been compiled by myself and is the result of my own investigations. It has not been submitted for any other degree and all sources of information have been duly acknowledged.

Aquatic Biology, Jan 4, 2012

The last detailed morphological descriptions of the juvenile stages of the parasitic copepod Lern... more The last detailed morphological descriptions of the juvenile stages of the parasitic copepod Lernaeocera branchialis (L., 1767) were written more than 70 yr ago, since which time both taxonomic nomenclature and available imaging technologies have changed substantially. In this paper a re-description of the free-swimming juvenile stages of L. branchialis is presented using a combination of traditional light microscopy and modern laser scanning confocal microscopy (LSCM) techniques. Detailed descriptions are provided of the nauplius I, nauplius II and copepodid stages and comparisons are made with the findings for other siphonostomatoids. Nauplius II is previously undescribed and several structures are described at the terminal tip which have not been found in other pennellids. With renewed interest in L. branchialis as a result of expanding gadoid aquaculture in North Atlantic countries, this re-description provides important information on its life history that may be useful for further research into this potentially devastating pathogen.

Parasitology, Feb 1, 2013

The life cycle of the parasitic copepod Lernaeocera branchialis involves 2 hosts, typically a ple... more The life cycle of the parasitic copepod Lernaeocera branchialis involves 2 hosts, typically a pleuronectiform host upon which development of larvae and mating of adults occurs and a subsequent gadoid host, upon which the adult female feeds and reproduces. Both the copepodid and adult female stages must therefore locate and identify a suitable host to continue the life cycle. Several mechanisms are potentially involved in locating a host and ensuring its suitability for infection. These may include mechano-reception to detect host movement and chemo-reception to recognize host-associated chemical cues, or kairomones. The aim of this study was to identify the role of kairomones in host location by adult L. branchialis, by analysing their behaviour in response to fish-derived chemicals. Experiments demonstrated that water conditioned by immersion of whiting, Merlangius merlangus, elicited host-seeking behaviour in L. branchialis, whereas cod-(Gadus morhua) conditioned water did not. Lernaeocera branchialis are considered a genetically homogeneous population infecting a range of gadoids. However, their differential response to whiting-and cod-derived chemicals in this study suggests that either there are genetically determined subspecies of L. branchialis or there is some form of environmental pre-conditioning that allows the parasite to preferentially recognize the host species from which it originated.

Elsevier eBooks, 2007

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.

Aquaculture, Aug 1, 2006

Modern Geographical Information Systems (GIS) offer a powerful modelling environment capable of h... more Modern Geographical Information Systems (GIS) offer a powerful modelling environment capable of handling large databases. They are a very suitable environment in which to develop a suite of tools designed for environmental management of aquaculture sites, including carrying capacity prediction, land-water interactions and multi-site effects. One such tool, presented here, is a fully integrated and validated particulate fish waste dispersion module which uses mass balance to estimate waste input and takes account of variable bathymetry and variable settling velocity for feed and faecal components. The model also incorporates the effect of cage movement on waste dispersion, the first such model to do so. When tidal range was low (1.67m), the maximum movement of a 22m diameter circular cage was 10.1m and 7.7m easting and northing respectively. Highest deposition from particulate fish waste is under the cage and incorporation of cage movement increased the effective area under a cage by 72%. This reduced peak deposition measurements by up to 32% and reduced the average modelled feed and faecal settlement at the cage centre by 23% and 11% respectively. The model was validated by comparing model predictions with observed deposition measured using sediment traps during three 2-week field trips at a fish farm on the west coast of Scotland. The mean ratio of observed to predicted waste deposition at 5-25m from the cage centre ranged from 0.9 to 1.06, whilst under the cage the model overpredicts deposition (observed/predicted = 2.21). Although far-field data was seen to be comparable the near-field discrepancies resulted in variable overall accuracy in the model. The overall accuracy based on August 2001 data was ± 50.9%, on February 2002 ± 72.8% and on April 2002 ± 50.6%. Summarizing the data resulted in an overall average predictive accuracy of ± 58.1%.

Ices Journal of Marine Science, Feb 19, 2018

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 the provision of "best" or consensus estimates for use in modelling. Additional and more consistent data collection and experimentation will help to fill these gaps. Furthermore, coordinated international efforts are required to generate a more complete picture of sea louse infections across all regions experiencing problems with sea lice.

한국수산과학회 양식분과 학술대회, May 1, 2015

Marine Policy, Feb 1, 2021

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.

Parasites & Vectors, Oct 27, 2011

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 behaviour patterns of the two species were similar and parasites were more active in red light and darkness than in white light. Four octopaminergic compounds were tested and all four inhibited the movements of parasites. Treatment ultimately led to death at low concentrations (0.2 μM), although prolonged exposure was necessary in some instances. Conclusions: Octopaminergic compounds may affect the parasite's ability to locate and remain on its host and these or related compounds might provide alternative or supplementary treatments for the control of G. salaris infections. With more research there is potential for use of octopaminergic compounds, which have minimal effects on the host or its environment, as parasite-specific treatments against G. salaris infections.

Aquatic Biology, Jan 4, 2012

The use of laser scanning confocal microscopy (LSCM) for creating taxonomic descriptions of copep... more The use of laser scanning confocal microscopy (LSCM) for creating taxonomic descriptions of copepods is investigated. A new technique is described, which employs a contour filter to process digital LSCM images, allowing taxonomic information to be quickly and accurately distilled into a simple illustration. LSCM allows the imaging of whole specimens, which can be rotated and viewed from any angle-a major benefit over light microscopy. Using this technique, it is suggested that taxonomic descriptions can be rapidly produced in a fraction of the time required to produce similar descriptions using traditional light microscopy and hand drawing techniques. Good staining of specimens is, however, essential to produce accurate descriptions and more research is required in this area. The use of LSCM for morphological taxonomy shows great potential, not only for producing taxonomic descriptions, but also providing a complementary adjunct to traditional type specimens in the form of 3D digital 'e-types' deposited in recognised international databases.

I would like to express my gratitude to my supervisors Andy Shinn and James Bron for their contin... more I would like to express my gratitude to my supervisors Andy Shinn and James Bron for their continuous support and guidance throughout my PhD. My passage through the PhD minefield was facilitated by Andy's optimism and enthusiasm, and James' good humour and critical eye, which helped me to achieve the high standard required. I would also like to thank James for the endless hours spent with me working on the confocal microscope and the statistical analysis of parasite behaviour data. Thanks to the Natural Environment Research Council for providing me with funding throughout the project, giving me the opportunity to work in the field of parasitology. Thanks to the staff at Longannet power station and Willie McBrien, the shrimp boat man, for providing me with enough infected fish for my experiments whenever I required them, and often at short notice. Thanks to the staff at the Institute of Aquaculture, especially Rob Aitken for use of the marine aquarium facility, Ian Elliot for use of the teaching lab and equipment, Linton Brown for guidance and use of the SEM and Denny Conway for assistance with digital photography and putting up with me in the lab! I would like to thank all my friends in the Parasitology group and Institute of Aquaculture, for creating a relaxed and friendly atmosphere, in which working is always a pleasure. Also thanks to Lisa Summers for always being there throughout the good and the bad times. Many thanks to my fishing buddies, Rob McKeown, Pat Reynolds and Mark Burns, for dragging me away from the lab when I needed a break and the many hours of good company and whisky drinking spent relaxing by the water's edge. Last, but not least, I would like to thank my parents for their unconditional love and support, both emotionally and financially. II Declaration I declare that this thesis has been compiled by myself and is the result of my own investigations. It has not been submitted for any other degree and all sources of information have been duly acknowledged.

Aquaculture, 2006

Modern Geographical Information Systems (GIS) offer a powerful modelling environment capable of h... more Modern Geographical Information Systems (GIS) offer a powerful modelling environment capable of handling large databases. They are a very suitable environment in which to develop a suite of tools designed for environmental management of aquaculture sites, including carrying capacity prediction, land-water interactions and multi-site effects. One such tool, presented here, is a fully integrated and validated particulate fish waste dispersion module which uses mass balance to estimate waste input and takes account of variable bathymetry and variable settling velocity for feed and faecal components. The model also incorporates the effect of cage movement on waste dispersion, the first such model to do so. When tidal range was low (1.67m), the maximum movement of a 22m diameter circular cage was 10.1m and 7.7m easting and northing respectively. Highest deposition from particulate fish waste is under the cage and incorporation of cage movement increased the effective area under a cage by 72%. This reduced peak deposition measurements by up to 32% and reduced the average modelled feed and faecal settlement at the cage centre by 23% and 11% respectively. The model was validated by comparing model predictions with observed deposition measured using sediment traps during three 2-week field trips at a fish farm on the west coast of Scotland. The mean ratio of observed to predicted waste deposition at 5-25m from the cage centre ranged from 0.9 to 1.06, whilst under the cage the model overpredicts deposition (observed/predicted = 2.21). Although far-field data was seen to be comparable the near-field discrepancies resulted in variable overall accuracy in the model. The overall accuracy based on August 2001 data was ± 50.9%, on February 2002 ± 72.8% and on April 2002 ± 50.6%. Summarizing the data resulted in an overall average predictive accuracy of ± 58.1%.

ICES Journal of Marine Science, 2018

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. 107.31millionto107.31 million to 107.31millionto134.14 million. Assuming parasites are responsible for losses of 1% to 10% of harvest-size fish, the value of these fish was estimated at 945.00millionto945.00 million to 945.00millionto9.45 billion. Combining the hatchery and growout figures, the parasites’ annual cost was tentatively estimated at 1.05billionto1.05 billion to 1.05billionto9.58 billion

Nematodes, also known as roundworms, are found in a wide range of aquatic and terrestrial habitat... more Nematodes, also known as roundworms, are found in a wide range of aquatic and terrestrial habitats, with over half of the known species being parasitic. Anisakid nematodes, which are commonly found in sea fish, are of particular importance as they are able to infect humans. The natural hosts of anisakids are whales and seals, but humans can become infected when raw or undercooked fish (e.g. cured or smoked) is eaten. Symptoms of anisakid infection (anisakiasis) often include nausea, stomach pain and vomiting. On rare occasions anisakid infection of humans can be fatal. With growing trends in the consumption of raw and undercooked fish, anisakiasis currently affects over 2000 people per annum worldwide, with 95% of cases located in Japan. In order to kill any anisakids present in fish, it must be either frozen or sufficiently cooked. However, even if there are no live anisakids, chemicals that they produce can still be present in fish flesh, which can cause allergic reactions in some people. An amendment in December 2011 of Annex III to Regulation (EC) No 853/2004, which concerns "treatment to kill viable parasites in fishery products for human consumption" permits that farmed fish do not need to be frozen to kill anisakids when intended to be marketed in a raw state (or is not intended to undergo a treatment that will kill viable parasites), where it can be proven that fish have been reared in an environment free of infection, or that adequate monitoring programmes are in place to verify that fishery products do not represent a health hazard with regards to anisakid worms. Although it is not possible to reduce anisakid infections in wild fish, in aquaculture, there is greater control over fish stocks so it is possible to prevent exposure to sources of nematode infection and to monitor infection levels to ensure that the fish are free from parasites. Previous research has shown that farmed Atlantic salmon in Scotland are free of anisakid infections. This study aims to analyse current farming practices for other Scottish mariculture species (Atlantic halibut, rainbow trout and sea trout) in order to identify potential sources / risks of anisakid infection, and to