Ken Collins - Academia.edu (original) (raw)
Papers by Ken Collins
European Environmental Law Review, Mar 1, 1995
This paper traces the development of European environment policy before going on to discuss the r... more This paper traces the development of European environment policy before going on to discuss the role of the European Parliament and its Environment Committee. After describing the institutional changes that have taken place over the past ten years at a European level, the article explores some further modifications to the Treaties which would facilitate environment policy making. The paper also highlights some of the specific policy areas that the Environment Committee is currently addressing and concludes with a look to the future prospects of European environment policy.
Seagrasses are flowering plants that develop extensive underwater meadows and play a key role in ... more Seagrasses are flowering plants that develop extensive underwater meadows and play a key role in the coastal ecosystem. In the last few years, several techniques have been developed to map and monitor seagrass beds in order to protect them. We present here the results of a survey using a profiling sonar-the Sediment Imager Sonar (SIS)-and a towed video sledge to study a Zostera marina bed off Calshot, southern UK. The survey aimed to test the instruments for seagrass detection and describe the area for the first time. Data processing from the SIS and video data will be presented along with correlation of the 2 instruments. From the SIS data, the bed elevation was recorded as the strongest backscatter along a beam. The presence of seagrass was indicated as a high backscatter intensity above the seabed. For each sweep, four parameters were calculated from the SIS data: depth of the seabed, Seagrass Index (used to assess seagrass presence), canopy height and vegetation patchiness. From the video, Zostera density was estimated together with macroalgae abundance and bottom type. The results of an algorithm developed to detect seagrass from the SIS data were tested against video data. Patchiness calculated from the SIS data was strongly correlated to seagrass density evaluated from the video, indicating that the parameter could be used for seagrass detection. Canopy height evaluated from the acoustic data was consistent with field observations. The SIS therefore proved to be a useful instrument for surveying seagrass beds although it needs to be tested over other seagrass types.
Advances in Invertebrates and Fish Telemetry, 1998
ABSTRACT
Aquaculture, 2015
ABSTRACT The precarious status of flat oyster Ostrea edulis stocks in Europe is widely acknowledg... more ABSTRACT The precarious status of flat oyster Ostrea edulis stocks in Europe is widely acknowledged. To build a scientific basis for oyster restoration, an elevated experimental reef stocked with O. edulis was established within Poole Bay (Dorset, UK). Oysters were out planted on twenty four oyster reef modules (80 cm above sea bed) and compared with oysters held on the sea bed close to each reef module to test the hypothesis that a reef habitat enhanced physiological performance. Filtration and respiration rates, condition index, haemolymph protein concentration, haemocyte counts and gonad maturation were measured as indicators of physiological performance. During the first 15 months of oyster reef deployment, water samples were collected at regular intervals at the sea bed and at a height of 80 cm from the sea bed to determine chlorophyll a concentration, total suspended solids and bacterial abundance. Total suspended solids were significantly higher at the sea bed than at 80 cm above the sea bed at every sampling interval, while bacterial abundance adjacent to the sea bed was significantly higher than 80 cm above the sea bed in August and November 2013 when temperature was 18 °C and 15 °C, respectively. The filtration rates of oysters varied with elevation (reef/sea bed) and months. Filtration rates of ‘reef oysters’ (oysters on elevated reefs) were significantly higher than ‘sea bed oysters’ (oysters held on the sea bed). Respiration rates varied among months but were not significantly affected by elevation (reef/sea bed). Elevation and month also affected the total number of haemocytes and the granulocyte population; reef oysters had significantly higher numbers of haemocytes than sea bed oysters. As current stocks of European flat oysters (O. edulis) in Europe have declined in both abundance and distribution, the results of this pilot study suggest that the culture of oysters on elevated reef structure represents at least a partial solution to improve O. edulis physiology for restoration in Europe.
Marine Ecology Progress Series, 2001
Crustaceana, 1994
In 1989 an experimental artificial reef, constructed with blocks made from stabilized coal-fired ... more In 1989 an experimental artificial reef, constructed with blocks made from stabilized coal-fired power station waste materials, was deployed in Poole Bay on the English south coast. A site was chosen on flat sandy seabed at a depth approximately 10 m below chart datum. Within a few weeks, research divers had observed lobsters on the reef, even though the reef blocks had been deposited on flat sand some distance (3 km) from the nearest natural reefs. Conventional tags were used in studies to investigate lobster movement around the reef structure between 1989 and 1992: 48% of the 114 individuals tagged have been recaptured at least once on the reef. Although a number of lobsters appear to have moved away from the reef altogether (16 of the reef-tagged lobsters have now been recaptured at a maximum of 15.7 km away from the artificial reef), one individual has now been observed on the reef for over 800 days. Lobsters colonized the new man-made structures quickly and many individuals have exhibited considerable long-term site loyalty. Artificial reefs may provide a method for long term lobster stock enhancement at specific sites, assuming habitat to be a major limiting factor on population size and structure. RÉSUMÉ En 1989, un récif artificiel expérimental, construit à l'aide de blocs provenant de déchets d'une centrale thermique a été installé dans la baie de Poole, sur la côte sud de l'Angleterre. Le site a été choisi sur un fond plat et sableux, à une profondeur d'environ 10 m au-dessous du zéro des cartes. Après quelques semaines, des chercheurs en plongée ont observé un certain nombre de homards sur le récif, bien que les blocs de rocher aient été déposés sur le sable à une certaine distance (3 km) des rochers naturels les plus proches. Des marques conventionnelles ont été utilisées pour étudier les mouvements des homards autour du récif de 1989 à 1992: 48% des 114 individus marqués ont été recapturés au moins une fois sur le récif. Bien qu'un certain nombre de homards semblent avoir complètement quitté le récif (16 des homards marqués du récif ont été maintenant recapturés à un maximum de 15,7 km du rocher artificiel), un inidividu a été observé sur le récif pendant plus de 800 jours. Les homards peuvent coloniser rapidement les structures nouvellement fabriquées par l'homme et beaucoup d'individus ont manifesté une très longue fidélité au site. Les rochers artificiels peuvent constituer un moyen pour accroître à long terme un stock de homards sur des sites spécifiques, en supposant que l'habitat est un facteur limitant majeur de la taille et de la structure d'une population.
Chemistry and Ecology, 1992
ABSTRACT
The Mary Rose Trust Ltd, 2003
Journal of Fish Biology, 1998
Diurnal fishes responded rapidly to decreased light levels during a total solar eclipse and sough... more Diurnal fishes responded rapidly to decreased light levels during a total solar eclipse and sought shelter in the reef. Nocturnal fishes sometimes left the cover of their daytime habitats. The activity cycles of diurnal reef fishes appear to be a direct response to changes in light level.
Journal of Experimental Marine Biology and Ecology, 2000
A telemetry system for studying decapod crustacean behaviour is described which uses low frequenc... more A telemetry system for studying decapod crustacean behaviour is described which uses low frequency, digitally encoded electromagnetic tags whose signals are detected with a grid of loop aerials on the seabed. Electromagnetic telemetry can be used to study short range movements of cryptic animals in topographically complex habitats that are not amenable to ultrasonic telemetry. Digital encoding allows many individuals to be monitored simultaneously and one or more behavioural, physiological or environmental variables to be telemetered. In the present system, tag signals convey identity and a measure of activity derived from an integral tilt switch. Translocational movements are indicated by detection of tags with different aerials. A central data logger located on the seabed decodes and records tag signals and environmental measurements. Design life of tags is. 1 year and the receiving system batteries are replaced by divers at intervals of up to 4 weeks. In field tests, crab (Cancer pagurus L.) and lobster (Homarus gammarus (L.)) activity was monitored at an artificial reef for 14 months. Examples of the type of information acquired are presented to illustrate the capabilities of the system and potential applications are discussed. Limitations of digital electromagnetic telemetry stem mainly from the short range of detection, the need for cables on the seabed and the size and shape of the transmitting tag.
Management of Biological Invasions, 2015
At 10.59 hours (Ecuadorian Time) on 26 February 1998 there was a solar eclipse at Pinta Island, C... more At 10.59 hours (Ecuadorian Time) on 26 February 1998 there was a solar eclipse at Pinta Island, Calápagos (Espenak and Anderson 1997; Figure 1). The eclipse began when the sun was at an altitude of 68° and the period of totality (sun completely obscured by the moon) lasted 3.5 mino Light levels during totality were equivalent to those at night, and planets and stars were visible to the human eye. The eclipse provided an opportunity to observe the effeds of changes in light intensity on the behavior of reef fishes. Reef fishes can be categorised as diurnal, nocturnal, al' crepuscular (Hobson 1965, 1972, McFarland 1991). In late morning, on reefs clase to the equator, only diurnal fishes are active and nocturnal or crepuscular fishes are sheltering within crevices or caves. The behavior and abundance of reef fishes was recorded before, during, and after the eclipse in an area of 10 m by 2 m at a depth of 710 m on the reef slope north of Pinta Island (Figure 1, 00° 37.77' N, 90...
European Environmental Law Review, Mar 1, 1995
This paper traces the development of European environment policy before going on to discuss the r... more This paper traces the development of European environment policy before going on to discuss the role of the European Parliament and its Environment Committee. After describing the institutional changes that have taken place over the past ten years at a European level, the article explores some further modifications to the Treaties which would facilitate environment policy making. The paper also highlights some of the specific policy areas that the Environment Committee is currently addressing and concludes with a look to the future prospects of European environment policy.
Seagrasses are flowering plants that develop extensive underwater meadows and play a key role in ... more Seagrasses are flowering plants that develop extensive underwater meadows and play a key role in the coastal ecosystem. In the last few years, several techniques have been developed to map and monitor seagrass beds in order to protect them. We present here the results of a survey using a profiling sonar-the Sediment Imager Sonar (SIS)-and a towed video sledge to study a Zostera marina bed off Calshot, southern UK. The survey aimed to test the instruments for seagrass detection and describe the area for the first time. Data processing from the SIS and video data will be presented along with correlation of the 2 instruments. From the SIS data, the bed elevation was recorded as the strongest backscatter along a beam. The presence of seagrass was indicated as a high backscatter intensity above the seabed. For each sweep, four parameters were calculated from the SIS data: depth of the seabed, Seagrass Index (used to assess seagrass presence), canopy height and vegetation patchiness. From the video, Zostera density was estimated together with macroalgae abundance and bottom type. The results of an algorithm developed to detect seagrass from the SIS data were tested against video data. Patchiness calculated from the SIS data was strongly correlated to seagrass density evaluated from the video, indicating that the parameter could be used for seagrass detection. Canopy height evaluated from the acoustic data was consistent with field observations. The SIS therefore proved to be a useful instrument for surveying seagrass beds although it needs to be tested over other seagrass types.
Advances in Invertebrates and Fish Telemetry, 1998
ABSTRACT
Aquaculture, 2015
ABSTRACT The precarious status of flat oyster Ostrea edulis stocks in Europe is widely acknowledg... more ABSTRACT The precarious status of flat oyster Ostrea edulis stocks in Europe is widely acknowledged. To build a scientific basis for oyster restoration, an elevated experimental reef stocked with O. edulis was established within Poole Bay (Dorset, UK). Oysters were out planted on twenty four oyster reef modules (80 cm above sea bed) and compared with oysters held on the sea bed close to each reef module to test the hypothesis that a reef habitat enhanced physiological performance. Filtration and respiration rates, condition index, haemolymph protein concentration, haemocyte counts and gonad maturation were measured as indicators of physiological performance. During the first 15 months of oyster reef deployment, water samples were collected at regular intervals at the sea bed and at a height of 80 cm from the sea bed to determine chlorophyll a concentration, total suspended solids and bacterial abundance. Total suspended solids were significantly higher at the sea bed than at 80 cm above the sea bed at every sampling interval, while bacterial abundance adjacent to the sea bed was significantly higher than 80 cm above the sea bed in August and November 2013 when temperature was 18 °C and 15 °C, respectively. The filtration rates of oysters varied with elevation (reef/sea bed) and months. Filtration rates of ‘reef oysters’ (oysters on elevated reefs) were significantly higher than ‘sea bed oysters’ (oysters held on the sea bed). Respiration rates varied among months but were not significantly affected by elevation (reef/sea bed). Elevation and month also affected the total number of haemocytes and the granulocyte population; reef oysters had significantly higher numbers of haemocytes than sea bed oysters. As current stocks of European flat oysters (O. edulis) in Europe have declined in both abundance and distribution, the results of this pilot study suggest that the culture of oysters on elevated reef structure represents at least a partial solution to improve O. edulis physiology for restoration in Europe.
Marine Ecology Progress Series, 2001
Crustaceana, 1994
In 1989 an experimental artificial reef, constructed with blocks made from stabilized coal-fired ... more In 1989 an experimental artificial reef, constructed with blocks made from stabilized coal-fired power station waste materials, was deployed in Poole Bay on the English south coast. A site was chosen on flat sandy seabed at a depth approximately 10 m below chart datum. Within a few weeks, research divers had observed lobsters on the reef, even though the reef blocks had been deposited on flat sand some distance (3 km) from the nearest natural reefs. Conventional tags were used in studies to investigate lobster movement around the reef structure between 1989 and 1992: 48% of the 114 individuals tagged have been recaptured at least once on the reef. Although a number of lobsters appear to have moved away from the reef altogether (16 of the reef-tagged lobsters have now been recaptured at a maximum of 15.7 km away from the artificial reef), one individual has now been observed on the reef for over 800 days. Lobsters colonized the new man-made structures quickly and many individuals have exhibited considerable long-term site loyalty. Artificial reefs may provide a method for long term lobster stock enhancement at specific sites, assuming habitat to be a major limiting factor on population size and structure. RÉSUMÉ En 1989, un récif artificiel expérimental, construit à l'aide de blocs provenant de déchets d'une centrale thermique a été installé dans la baie de Poole, sur la côte sud de l'Angleterre. Le site a été choisi sur un fond plat et sableux, à une profondeur d'environ 10 m au-dessous du zéro des cartes. Après quelques semaines, des chercheurs en plongée ont observé un certain nombre de homards sur le récif, bien que les blocs de rocher aient été déposés sur le sable à une certaine distance (3 km) des rochers naturels les plus proches. Des marques conventionnelles ont été utilisées pour étudier les mouvements des homards autour du récif de 1989 à 1992: 48% des 114 individus marqués ont été recapturés au moins une fois sur le récif. Bien qu'un certain nombre de homards semblent avoir complètement quitté le récif (16 des homards marqués du récif ont été maintenant recapturés à un maximum de 15,7 km du rocher artificiel), un inidividu a été observé sur le récif pendant plus de 800 jours. Les homards peuvent coloniser rapidement les structures nouvellement fabriquées par l'homme et beaucoup d'individus ont manifesté une très longue fidélité au site. Les rochers artificiels peuvent constituer un moyen pour accroître à long terme un stock de homards sur des sites spécifiques, en supposant que l'habitat est un facteur limitant majeur de la taille et de la structure d'une population.
Chemistry and Ecology, 1992
ABSTRACT
The Mary Rose Trust Ltd, 2003
Journal of Fish Biology, 1998
Diurnal fishes responded rapidly to decreased light levels during a total solar eclipse and sough... more Diurnal fishes responded rapidly to decreased light levels during a total solar eclipse and sought shelter in the reef. Nocturnal fishes sometimes left the cover of their daytime habitats. The activity cycles of diurnal reef fishes appear to be a direct response to changes in light level.
Journal of Experimental Marine Biology and Ecology, 2000
A telemetry system for studying decapod crustacean behaviour is described which uses low frequenc... more A telemetry system for studying decapod crustacean behaviour is described which uses low frequency, digitally encoded electromagnetic tags whose signals are detected with a grid of loop aerials on the seabed. Electromagnetic telemetry can be used to study short range movements of cryptic animals in topographically complex habitats that are not amenable to ultrasonic telemetry. Digital encoding allows many individuals to be monitored simultaneously and one or more behavioural, physiological or environmental variables to be telemetered. In the present system, tag signals convey identity and a measure of activity derived from an integral tilt switch. Translocational movements are indicated by detection of tags with different aerials. A central data logger located on the seabed decodes and records tag signals and environmental measurements. Design life of tags is. 1 year and the receiving system batteries are replaced by divers at intervals of up to 4 weeks. In field tests, crab (Cancer pagurus L.) and lobster (Homarus gammarus (L.)) activity was monitored at an artificial reef for 14 months. Examples of the type of information acquired are presented to illustrate the capabilities of the system and potential applications are discussed. Limitations of digital electromagnetic telemetry stem mainly from the short range of detection, the need for cables on the seabed and the size and shape of the transmitting tag.
Management of Biological Invasions, 2015
At 10.59 hours (Ecuadorian Time) on 26 February 1998 there was a solar eclipse at Pinta Island, C... more At 10.59 hours (Ecuadorian Time) on 26 February 1998 there was a solar eclipse at Pinta Island, Calápagos (Espenak and Anderson 1997; Figure 1). The eclipse began when the sun was at an altitude of 68° and the period of totality (sun completely obscured by the moon) lasted 3.5 mino Light levels during totality were equivalent to those at night, and planets and stars were visible to the human eye. The eclipse provided an opportunity to observe the effeds of changes in light intensity on the behavior of reef fishes. Reef fishes can be categorised as diurnal, nocturnal, al' crepuscular (Hobson 1965, 1972, McFarland 1991). In late morning, on reefs clase to the equator, only diurnal fishes are active and nocturnal or crepuscular fishes are sheltering within crevices or caves. The behavior and abundance of reef fishes was recorded before, during, and after the eclipse in an area of 10 m by 2 m at a depth of 710 m on the reef slope north of Pinta Island (Figure 1, 00° 37.77' N, 90...