The demand for seafood products on the global market is rising, particularly in Asia, as affluenc... more The demand for seafood products on the global market is rising, particularly in Asia, as affluence and appreciation of the health benefits of seafood increase. This is coupled with a capture fishery that, at best, is set for stagnation and, at worst, significant collapse. Global aquaculture is the fastest growing sector of the food industry and currently accounts for approximately 45.6% of the world's fish consumption. However, the rapid development of extensive and semi-extensive systems, particularly intensive marine-fed aquaculture, has resulted in worldwide concern about the potential environmental, economic, and social impacts of such systems. In recent years, there has been a significant amount of research conducted on the development of sustainable saltwater-based food production systems through mechanical (e.g., recirculatory aquaculture (RAS) systems) methods and ecosystem-based approaches (e.g., integrated multi-trophic aquaculture (IMTA)). This review article will examine the potential negative impacts of monocultural saltwater aquaculture operations and review established (RAS) and novel (IMTA; constructed wetlands; saltwater aquaponics) saltwater-based food production systems and discuss their (potential) contribution to the development of sustainable and environmentally-friendly systems.
Aquatic Conservation: Marine and Freshwater Ecosystems, 2012
1. Marine aquaculture relies on coastal habitats that will be affected by climate change. This re... more 1. Marine aquaculture relies on coastal habitats that will be affected by climate change. This review assesses current knowledge of the threats and opportunities of climate change for aquaculture in the UK and Ireland, focusing on the most commonly farmed species, blue mussels (Mytilus edulis) and Atlantic salmon (Salmo salar).
Aquatic Conservation: Marine and Freshwater Ecosystems, 2012
1. Marine aquaculture relies on coastal habitats that will be affected by climate change. This re... more 1. Marine aquaculture relies on coastal habitats that will be affected by climate change. This review assesses current knowledge of the threats and opportunities of climate change for aquaculture in the UK and Ireland, focusing on the most commonly farmed species, blue mussels (Mytilus edulis) and Atlantic salmon (Salmo salar).
Changes in community structure of an intertidal, macrobenthic community in the vicinity of a Cras... more Changes in community structure of an intertidal, macrobenthic community in the vicinity of a Crassostrea gigas (Thunberg) cultivation site were studied. Samples were taken underneath trestles, in access lanes and at a control site. No evidence of organic enrichment was found, linked to the highly dissipative nature of the study site, the latter as evidenced by the granulometric composition of the substrate and the species encountered. Compared to the community at a control site, the macrofauna in the access lanes has undergone species displacements and changes in numerical abundance of surficial living forms and shallow, fragile burrowers. This is postulated to be linked to physical disturbance by heavy vehicle traffic.
Distributional and abundance data on seventeen cephalopod species from three demersal trawl serie... more Distributional and abundance data on seventeen cephalopod species from three demersal trawl series are presented. Data from one the CEFAS March Celtic Sea Groundfish Survey cover the years 1994-1998 inclusive and a depth range of 57-580 m. Data from two Marine Institute surveys was for October-November 1997 only. One of these surveys was west and south west of Ireland between depths of 27-328 m, the other was conducted in deepwater (520-1174 m) to the northwest. Eleven cephalopod species were caught (14,981 individual cephalopods) during the five CEFAS surveys. Spatial and bathymetric distribution data are presented for the species caught and the interannual variability is discussed. The most numerous species in catches was Loligo forbesi (n = 6,803), however, the highest biomass caught was Illex coindetii (418.3kg). Alloteuthis subulata were common close to shore in water depth of less than 75 m. Swept area density estimates are reported for the most abundant species in catches. Ten cephalopod species were caught during the Marine Institute west coast groundfish survey (774 specimens were examined out of an estimated 8,712 caught). The results show broadly similar patterns in species composition, distribution and abundance to the CEFAS survey. Todaropsis eblanae was the second most numerous species in the survey. Only six cephalopod species (n =196) were caught in the Marine Institute deepwater trawl survey. Todarodes sagittatus was the most common species caught. Deepwater octopods including Benthoctopus piscatorum, Benthoctopus ergasticus and Opisthoteuthis massyae were also caught. This chapter provides a base line of data on cephalopod species which are caught in trawl surveys west of Ireland and in the Celtic Sea.
There is a pressing need to protect the ecology of nearshore marine habitats that are used for an... more There is a pressing need to protect the ecology of nearshore marine habitats that are used for an ever increasing range of activities. In particular, fisheries managers need to consider both environmental and socioeconomic issues in coastal areas owing to the environmental changes that can occur as a result of cultivation and harvesting processes associated with mariculture. Bivalve cultivation can be broadly split into three main processes: (1) seed collection, (2) seed nursery and on-growing, (3) harvesting. The environmental impacts of each cultivation stage will vary depending on the species in question and the techniques used. In many instances, commercial species are reared as seed in hatcheries prior to seeding, with few effects on the environment. However, while some species are collected from the wild using benign techniques such as spat collectors, others are extracted using intrusive devices such as dredges. A growing number of studies of the ecological effects of mechani...
Comparative Biochemistry and Physiology Part B: Comparative Biochemistry, 1994
The effect of Mg 2+ (0.84-6.74 mM) and Ca z+ (0.18-1.45 mM) on the Lowry method was studied. Mg z... more The effect of Mg 2+ (0.84-6.74 mM) and Ca z+ (0.18-1.45 mM) on the Lowry method was studied. Mg z+ and Ca 2÷ affected the absorbance of both the protein-free blank and protein samples. The tolerable Hmit was < 0.84 mM for Mg 2+ and 0.55 mM for Ca z+. The interference by Mg 2+ was more significant than Ca 2+ at the same concentration. A hypothesis was proposed in respect of the mechanism of interference by MgZ+: the Mg(OED2 precipitate binds with protein and some constituent of Lowry reagent B and thus reduces their sensitivity to Folin reagent.
Journal of the Marine Biological Association of the United Kingdom, 1981
... of 0-9 and gross productivity was calculated assuming a photosynthetic quotient (pQ) of 1-5. ... more ... of 0-9 and gross productivity was calculated assuming a photosynthetic quotient (pQ) of 1-5. Although Strickland & Parsons ... the identifiable flagellates which were present Platymonas spp., Cryptomonas spp., Eutreptiella sp., Dinobryon sp., and Prasinocladus marinus were the ...
Journal of the Marine Biological Association of the United Kingdom, 1995
... Despite increased recent research activity, important gaps in the knowledge of the biology of... more ... Despite increased recent research activity, important gaps in the knowledge of the biology of L. forbesi remain, including accurate estimations of age and growth. Cephalopods are typically short-lived and semelparous (Forsythe & Van Heukelem, 1987) and the estimation of ...
Journal of the Marine Biological Association of the United Kingdom, 1988
... Galway. Thanks too to Dr T. Cross for critically reading the manuscript. ... Population genet... more ... Galway. Thanks too to Dr T. Cross for critically reading the manuscript. ... Population genetics of marine pelecypods. IV. Selection, migration and genetic differentiation in the blue mussel Mytilus edulis. Evolution, 30, 2-32. MATHERS, NF, 1975. ...
Journal of the Marine Biological Association of the United Kingdom, 1995
ABSTRACT p1 Present address: Department of Zoology, University of Aberdeen, Tillydrone Avenue, Ab... more ABSTRACT p1 Present address: Department of Zoology, University of Aberdeen, Tillydrone Avenue, Aberdeen, AB9 2TN.
... for Reseeding Programmes Iris wernefiB, Stefan ~lothmann' and Gavin urn ell* quacu ... sp... more ... for Reseeding Programmes Iris wernefiB, Stefan ~lothmann' and Gavin urn ell* quacu ... species. These two distributions were compared by means of the Brandt-Snedecor multiple-contingency-table X2 test (df = 6, P 5 0.05) (Sachs 1984). ...
The chemical composition and fatty acid pro®le of the tray-cultured Paci®c oyster (Crassostrea gi... more The chemical composition and fatty acid pro®le of the tray-cultured Paci®c oyster (Crassostrea gigas) were measured and compared over a 13 month period. Oysters (120±150 g) were cultured in Cork Harbour and samples taken for analysis at monthly intervals. The moisture, fat, protein, glycogen and ash contents of the¯esh were analysed. The fatty acid pro®le of the¯esh was analysed by gas chromatography. The condition indices of the oysters were determined. The chemical composition of the oysters grown in Cork Harbour was similar to literature values for the same species grown in Paci®c waters. Ranges for the chemical composition (dry¯esh weight basis) were: fat (7.8±8.7%), protein (39.1±53.1%), glycogen (21.6±38.9%) and ash (4.0±12.1%).
... SISSEL ANDERSEN1∗, GAVIN BURNELL2 and ØIVIND BERGH3 1Institute of Marine Research, Austevoll ... more ... SISSEL ANDERSEN1∗, GAVIN BURNELL2 and ØIVIND BERGH3 1Institute of Marine Research, Austevoll Aquaculture Research Station, N-5392 Storebø, Norway ... Taylor, JE, Gunn, B., Williams, P. and McNicoll, I. (1994) An investigation of techniques for the hatchery and ...
Next-generation concepts for solid-state memory devices are based on current-driven domain wall p... more Next-generation concepts for solid-state memory devices are based on current-driven domain wall propagation, where the wall velocity governs the device performance. It has been shown that the domain wall velocity and the direction of travel is controlled by the nature of the wall and its chirality. This chirality is attributed to effects emerging from the lack of inversion symmetry at the interface between a ferromagnet and a heavy metal, leading to an interfacial Dzyaloshinskii-Moriya interaction that can control the shape and chirality of the magnetic domain wall. Here we present direct imaging of domain walls in Pt/Co/AlO$_x$ films using Lorentz transmission electron microscopy, demonstrating the presence of homochiral, and thus topologically protected, N\'{e}el walls. Such domain walls are good candidates for dense data storage, bringing the bit size down close to the limit of the domain wall width.
Andreev reflection Spectroscopy is a well established method to measure the transport spin-polari... more Andreev reflection Spectroscopy is a well established method to measure the transport spin-polarization in magnetic films. Here we discuss the prospects for using planar Andreev junctions to detect spin accumulation in the non-magnetic semiconductor InAs. Here we compare Andreev spectra from planar fabricated Pb/InAs junctions and point-contact measurements. Planar junctions yield considerably lower smearing than point-contacts but the barrier parameter
The DC Josephson effect is theoretically studied in a planar junction in which a two dimensional ... more The DC Josephson effect is theoretically studied in a planar junction in which a two dimensional electron gas (2DEG) infinite in lateral directions is in contact with two superconducting electrodes placed on top of the 2DEG. An energy gap in the excitation spectrum is created in the 2DEG due to the proximity effect. It is shown that under certain conditions, the region of the 2DEG underneath the superconductors is analogous to a superconducting region with an order parameter ε g exp(iφ), where ε g (ε g < ∆) depends on the interface transmittance and the Fermi velocity mismatch between the superconductors and the 2DEG.
The demand for seafood products on the global market is rising, particularly in Asia, as affluenc... more The demand for seafood products on the global market is rising, particularly in Asia, as affluence and appreciation of the health benefits of seafood increase. This is coupled with a capture fishery that, at best, is set for stagnation and, at worst, significant collapse. Global aquaculture is the fastest growing sector of the food industry and currently accounts for approximately 45.6% of the world's fish consumption. However, the rapid development of extensive and semi-extensive systems, particularly intensive marine-fed aquaculture, has resulted in worldwide concern about the potential environmental, economic, and social impacts of such systems. In recent years, there has been a significant amount of research conducted on the development of sustainable saltwater-based food production systems through mechanical (e.g., recirculatory aquaculture (RAS) systems) methods and ecosystem-based approaches (e.g., integrated multi-trophic aquaculture (IMTA)). This review article will examine the potential negative impacts of monocultural saltwater aquaculture operations and review established (RAS) and novel (IMTA; constructed wetlands; saltwater aquaponics) saltwater-based food production systems and discuss their (potential) contribution to the development of sustainable and environmentally-friendly systems.
Aquatic Conservation: Marine and Freshwater Ecosystems, 2012
1. Marine aquaculture relies on coastal habitats that will be affected by climate change. This re... more 1. Marine aquaculture relies on coastal habitats that will be affected by climate change. This review assesses current knowledge of the threats and opportunities of climate change for aquaculture in the UK and Ireland, focusing on the most commonly farmed species, blue mussels (Mytilus edulis) and Atlantic salmon (Salmo salar).
Aquatic Conservation: Marine and Freshwater Ecosystems, 2012
1. Marine aquaculture relies on coastal habitats that will be affected by climate change. This re... more 1. Marine aquaculture relies on coastal habitats that will be affected by climate change. This review assesses current knowledge of the threats and opportunities of climate change for aquaculture in the UK and Ireland, focusing on the most commonly farmed species, blue mussels (Mytilus edulis) and Atlantic salmon (Salmo salar).
Changes in community structure of an intertidal, macrobenthic community in the vicinity of a Cras... more Changes in community structure of an intertidal, macrobenthic community in the vicinity of a Crassostrea gigas (Thunberg) cultivation site were studied. Samples were taken underneath trestles, in access lanes and at a control site. No evidence of organic enrichment was found, linked to the highly dissipative nature of the study site, the latter as evidenced by the granulometric composition of the substrate and the species encountered. Compared to the community at a control site, the macrofauna in the access lanes has undergone species displacements and changes in numerical abundance of surficial living forms and shallow, fragile burrowers. This is postulated to be linked to physical disturbance by heavy vehicle traffic.
Distributional and abundance data on seventeen cephalopod species from three demersal trawl serie... more Distributional and abundance data on seventeen cephalopod species from three demersal trawl series are presented. Data from one the CEFAS March Celtic Sea Groundfish Survey cover the years 1994-1998 inclusive and a depth range of 57-580 m. Data from two Marine Institute surveys was for October-November 1997 only. One of these surveys was west and south west of Ireland between depths of 27-328 m, the other was conducted in deepwater (520-1174 m) to the northwest. Eleven cephalopod species were caught (14,981 individual cephalopods) during the five CEFAS surveys. Spatial and bathymetric distribution data are presented for the species caught and the interannual variability is discussed. The most numerous species in catches was Loligo forbesi (n = 6,803), however, the highest biomass caught was Illex coindetii (418.3kg). Alloteuthis subulata were common close to shore in water depth of less than 75 m. Swept area density estimates are reported for the most abundant species in catches. Ten cephalopod species were caught during the Marine Institute west coast groundfish survey (774 specimens were examined out of an estimated 8,712 caught). The results show broadly similar patterns in species composition, distribution and abundance to the CEFAS survey. Todaropsis eblanae was the second most numerous species in the survey. Only six cephalopod species (n =196) were caught in the Marine Institute deepwater trawl survey. Todarodes sagittatus was the most common species caught. Deepwater octopods including Benthoctopus piscatorum, Benthoctopus ergasticus and Opisthoteuthis massyae were also caught. This chapter provides a base line of data on cephalopod species which are caught in trawl surveys west of Ireland and in the Celtic Sea.
There is a pressing need to protect the ecology of nearshore marine habitats that are used for an... more There is a pressing need to protect the ecology of nearshore marine habitats that are used for an ever increasing range of activities. In particular, fisheries managers need to consider both environmental and socioeconomic issues in coastal areas owing to the environmental changes that can occur as a result of cultivation and harvesting processes associated with mariculture. Bivalve cultivation can be broadly split into three main processes: (1) seed collection, (2) seed nursery and on-growing, (3) harvesting. The environmental impacts of each cultivation stage will vary depending on the species in question and the techniques used. In many instances, commercial species are reared as seed in hatcheries prior to seeding, with few effects on the environment. However, while some species are collected from the wild using benign techniques such as spat collectors, others are extracted using intrusive devices such as dredges. A growing number of studies of the ecological effects of mechani...
Comparative Biochemistry and Physiology Part B: Comparative Biochemistry, 1994
The effect of Mg 2+ (0.84-6.74 mM) and Ca z+ (0.18-1.45 mM) on the Lowry method was studied. Mg z... more The effect of Mg 2+ (0.84-6.74 mM) and Ca z+ (0.18-1.45 mM) on the Lowry method was studied. Mg z+ and Ca 2÷ affected the absorbance of both the protein-free blank and protein samples. The tolerable Hmit was < 0.84 mM for Mg 2+ and 0.55 mM for Ca z+. The interference by Mg 2+ was more significant than Ca 2+ at the same concentration. A hypothesis was proposed in respect of the mechanism of interference by MgZ+: the Mg(OED2 precipitate binds with protein and some constituent of Lowry reagent B and thus reduces their sensitivity to Folin reagent.
Journal of the Marine Biological Association of the United Kingdom, 1981
... of 0-9 and gross productivity was calculated assuming a photosynthetic quotient (pQ) of 1-5. ... more ... of 0-9 and gross productivity was calculated assuming a photosynthetic quotient (pQ) of 1-5. Although Strickland & Parsons ... the identifiable flagellates which were present Platymonas spp., Cryptomonas spp., Eutreptiella sp., Dinobryon sp., and Prasinocladus marinus were the ...
Journal of the Marine Biological Association of the United Kingdom, 1995
... Despite increased recent research activity, important gaps in the knowledge of the biology of... more ... Despite increased recent research activity, important gaps in the knowledge of the biology of L. forbesi remain, including accurate estimations of age and growth. Cephalopods are typically short-lived and semelparous (Forsythe & Van Heukelem, 1987) and the estimation of ...
Journal of the Marine Biological Association of the United Kingdom, 1988
... Galway. Thanks too to Dr T. Cross for critically reading the manuscript. ... Population genet... more ... Galway. Thanks too to Dr T. Cross for critically reading the manuscript. ... Population genetics of marine pelecypods. IV. Selection, migration and genetic differentiation in the blue mussel Mytilus edulis. Evolution, 30, 2-32. MATHERS, NF, 1975. ...
Journal of the Marine Biological Association of the United Kingdom, 1995
ABSTRACT p1 Present address: Department of Zoology, University of Aberdeen, Tillydrone Avenue, Ab... more ABSTRACT p1 Present address: Department of Zoology, University of Aberdeen, Tillydrone Avenue, Aberdeen, AB9 2TN.
... for Reseeding Programmes Iris wernefiB, Stefan ~lothmann' and Gavin urn ell* quacu ... sp... more ... for Reseeding Programmes Iris wernefiB, Stefan ~lothmann' and Gavin urn ell* quacu ... species. These two distributions were compared by means of the Brandt-Snedecor multiple-contingency-table X2 test (df = 6, P 5 0.05) (Sachs 1984). ...
The chemical composition and fatty acid pro®le of the tray-cultured Paci®c oyster (Crassostrea gi... more The chemical composition and fatty acid pro®le of the tray-cultured Paci®c oyster (Crassostrea gigas) were measured and compared over a 13 month period. Oysters (120±150 g) were cultured in Cork Harbour and samples taken for analysis at monthly intervals. The moisture, fat, protein, glycogen and ash contents of the¯esh were analysed. The fatty acid pro®le of the¯esh was analysed by gas chromatography. The condition indices of the oysters were determined. The chemical composition of the oysters grown in Cork Harbour was similar to literature values for the same species grown in Paci®c waters. Ranges for the chemical composition (dry¯esh weight basis) were: fat (7.8±8.7%), protein (39.1±53.1%), glycogen (21.6±38.9%) and ash (4.0±12.1%).
... SISSEL ANDERSEN1∗, GAVIN BURNELL2 and ØIVIND BERGH3 1Institute of Marine Research, Austevoll ... more ... SISSEL ANDERSEN1∗, GAVIN BURNELL2 and ØIVIND BERGH3 1Institute of Marine Research, Austevoll Aquaculture Research Station, N-5392 Storebø, Norway ... Taylor, JE, Gunn, B., Williams, P. and McNicoll, I. (1994) An investigation of techniques for the hatchery and ...
Next-generation concepts for solid-state memory devices are based on current-driven domain wall p... more Next-generation concepts for solid-state memory devices are based on current-driven domain wall propagation, where the wall velocity governs the device performance. It has been shown that the domain wall velocity and the direction of travel is controlled by the nature of the wall and its chirality. This chirality is attributed to effects emerging from the lack of inversion symmetry at the interface between a ferromagnet and a heavy metal, leading to an interfacial Dzyaloshinskii-Moriya interaction that can control the shape and chirality of the magnetic domain wall. Here we present direct imaging of domain walls in Pt/Co/AlO$_x$ films using Lorentz transmission electron microscopy, demonstrating the presence of homochiral, and thus topologically protected, N\'{e}el walls. Such domain walls are good candidates for dense data storage, bringing the bit size down close to the limit of the domain wall width.
Andreev reflection Spectroscopy is a well established method to measure the transport spin-polari... more Andreev reflection Spectroscopy is a well established method to measure the transport spin-polarization in magnetic films. Here we discuss the prospects for using planar Andreev junctions to detect spin accumulation in the non-magnetic semiconductor InAs. Here we compare Andreev spectra from planar fabricated Pb/InAs junctions and point-contact measurements. Planar junctions yield considerably lower smearing than point-contacts but the barrier parameter
The DC Josephson effect is theoretically studied in a planar junction in which a two dimensional ... more The DC Josephson effect is theoretically studied in a planar junction in which a two dimensional electron gas (2DEG) infinite in lateral directions is in contact with two superconducting electrodes placed on top of the 2DEG. An energy gap in the excitation spectrum is created in the 2DEG due to the proximity effect. It is shown that under certain conditions, the region of the 2DEG underneath the superconductors is analogous to a superconducting region with an order parameter ε g exp(iφ), where ε g (ε g < ∆) depends on the interface transmittance and the Fermi velocity mismatch between the superconductors and the 2DEG.
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Papers by Gavin Burnell