2013. Mortality of migratory birds from marine commercial fisheries and offshore oil and gas prod... more 2013. Mortality of migratory birds from marine commercial fisheries and offshore oil and gas production in Canada. Avian Conservation and Ecology 8(2): 4. http://dx.
ABSTRACT: This review paper identifies the main effects of oil and gas drilling waste on benthic
... more ABSTRACT: This review paper identifies the main effects of oil and gas drilling waste on benthic
environments. We identified 26 papers and technical reports that surveyed sediment samples from
72 production or exploration platform sites to assess the zone of influence of sediment contamina-
tion and biological effects on benthic communities. While oil-based fluids are now rarely used in
the marine context, their release has had large-scale (out to 6 km) and persistent (decadal time
scale) impacts on benthic communities. The zone of influence of water-based drilling fluids as
determined by sediment barium concentration was larger (2 to 20 km) than for synthetic-based
fluids (200 to 2000 m). The zone of biological effects on benthic community diversity and abun-
dance ranged from 100 to 1000 m for both water and synthetic fluids. Effects include changes in
benthic species diversity, abundance and alterations to community structure. Functional changes
included a loss of suspension-feeding species and increases in deposit feeders and polychaetes. In
general, this review demonstrates a loss of benthic biodiversity and suspension-feeding commu-
nities due to oil exploration and production and the potential for large-scale effects on sensitive
communities such as deep-sea, coral and vegetated habitats. Current research gaps and priorities
are identified.
Habitat fragmentation is thought to create a barrier to individual movements particularly for are... more Habitat fragmentation is thought to create a barrier to individual movements particularly for area-sensitive species which, by definition, prefer to breed in large tracts of forest. For two breeding seasons, we radio-tracked an area-sensitive species, the scarlet tanager Piranga olivacea, in a fragmented landscape in northeastern PA. We found that scarlet tanagers made extensive and frequent movements among fragments. Paired males were less likely to leave their capture fragment, and traveled shorter distances. Unpaired males in fragments had two distinct tactics we labeled: ''Sedentary'' and ''Mobile''. Sedentary males stayed at one fragment and sang at high rates, while mobile males spent 58% of the total time tracked off their capture fragment and traveled over a kilometer away from the capture site over open fields and through forests. Mobile males were not floaters per se because they were territorial (i.e., singing) in multiple sites. Habitat structure of a fragment did not correlate with the percent time a male spent off the capture fragment. Males in fragments experienced lower pairing success and were more likely to be first time breeders compared to males in continuous forest. Our results suggest that movements by scarlet tanagers in fragmented landscapes are not restricted during the breeding season, and that these movements are related directly to pairing status and indirectly to population density.
We investigated patterns of variation of feather and bill ornaments of Crested Auklets Aethia cri... more We investigated patterns of variation of feather and bill ornaments of Crested Auklets Aethia cristatella, a monogamous seabird, based on 963 individuals measured in the years 1990 to 1998. Three prominent ornaments were displayed: a forehead crest, composed of 11 -31 curved feathers averaging about 40 mm in length, bilaterally symmetrical white auricular plumes on the sides of the head behind the eyes, averaging about 30 mm in length, and brightly coloured semi-circular rictal plates at the corners of the bill. As in other putative sexually selected traits, auklet ornaments were more variable across individuals than non-ornamental traits. Crest length and auricular plume length were positively correlated within individuals but not across years. Among the traits measured there was evidence for slight sexual dimorphism for the auricular plume and rictal plate ornaments and for culmen length and tarsus (males were slightly larger than females) but not for the crest ornament. Breeding adult females and males had greater crest and plume ornament expression than non-breeding adults. Paradoxically, females' crests and rictal plates were more variable than males' crests and rictal plates. Based on independent samples, the expression of feather ornaments and rictal plate varied among years between 1990 and 1998. Crested Auklet ornaments did not vary in concert with the ornaments of Whiskered Aethia pygmaea and Least Auklets Aethia pusilla during this period. Crested Auklet subadults had smaller ornaments than adults. Based on adults remeasured after an interval of one to seven years, the size of individuals' feather ornaments increased with age. We found no relationship between auricular plume length and asymmetry. Male auricular plumes and female crests were weakly correlated with body condition.
2013. Mortality of migratory birds from marine commercial fisheries and offshore oil and gas prod... more 2013. Mortality of migratory birds from marine commercial fisheries and offshore oil and gas production in Canada. Avian Conservation and Ecology 8(2): 4. http://dx.
ABSTRACT During the last 25 years, North America has experienced a significant increase in Double... more ABSTRACT During the last 25 years, North America has experienced a significant increase in Double-crested Cormorants (Phalacrocorax auritus). The increase has caused concern among wildlife and fisheries managers dealing with the perceived and/or real impacts of this bird on fisheries. Cormorant foraging and breeding ecology were examined at a large (>6,000 pairs), unmanaged colony in Lake Ontario, Canada. Chick diet, feeding rates and productivity were evaluated during 2006 and 2007. In 2007, the proportion of adult cormorants making long-range foraging trips (more than ten kilometers) during different stages of the breeding season was estimated. Alewife (Alosa pseudoharengus) composed greater than 86% of chick diet by mass during both years; suggesting that cormorants did not often prey on sport fish for feeding chicks. Chicks were fed approximately 4.5 times per day in 2006, which was significantly lower than 5.9 feeds per day during 2007. Productivity was high in both years, with 2.2 and 1.9 chicks produced per nest in 2006 and 2007, respectively. The decrease in productivity corresponded with an increase in colony size, from 6,125 to 7,241 pairs. In 2007, approximately one-fifth of the nesting colony foraged at least ten kilometers throughout the breeding season. Cormorants fed their chicks very few sport fish in the Toronto area; however, more work is required to determine whether the consumption of Alewife by cormorants represents competition with sport fish for prey.
Journal of Environmental Assessment Policy and Management, 2008
The Environmental Assessment (EA) process should involve the generation of testable predictions g... more The Environmental Assessment (EA) process should involve the generation of testable predictions generated using clearly stated methods and followed by the collection of environmental monitoring data. Follow-up programs should aim to determine the accuracy of the initial predictions. We examined the follow-up process for six oil and gas extraction projects in eastern Canada with respect to assessing batch spill (< 50 barrels of hydrocarbons and synthetic hydrocarbons) predictions. For three projects we compared oil spill frequency predictions to observed data. All three projects exceeded their predicted frequencies and two projects by ratios (actual to predicted) greater than six. Spill histories from earlier projects, clearly exceeding predictions of future projects, are not provided in subsequent oil and gas EAs for the region, when there were opportunities to do so. We provide recommendations on how to strengthen the quality of EAs and increase protection of the marine environment in Canada.
We investigated patterns of variation of feather and bill ornaments of Crested Auklets Aethia cri... more We investigated patterns of variation of feather and bill ornaments of Crested Auklets Aethia cristatella, a monogamous seabird, based on 963 individuals measured in the years 1990 to 1998. Three prominent ornaments were displayed: a forehead crest, composed of 11 -31 curved feathers averaging about 40 mm in length, bilaterally symmetrical white auricular plumes on the sides of the head behind the eyes, averaging about 30 mm in length, and brightly coloured semi-circular rictal plates at the corners of the bill. As in other putative sexually selected traits, auklet ornaments were more variable across individuals than non-ornamental traits. Crest length and auricular plume length were positively correlated within individuals but not across years. Among the traits measured there was evidence for slight sexual dimorphism for the auricular plume and rictal plate ornaments and for culmen length and tarsus (males were slightly larger than females) but not for the crest ornament. Breeding adult females and males had greater crest and plume ornament expression than non-breeding adults. Paradoxically, females' crests and rictal plates were more variable than males' crests and rictal plates. Based on independent samples, the expression of feather ornaments and rictal plate varied among years between 1990 and 1998. Crested Auklet ornaments did not vary in concert with the ornaments of Whiskered Aethia pygmaea and Least Auklets Aethia pusilla during this period. Crested Auklet subadults had smaller ornaments than adults. Based on adults remeasured after an interval of one to seven years, the size of individuals' feather ornaments increased with age. We found no relationship between auricular plume length and asymmetry. Male auricular plumes and female crests were weakly correlated with body condition.
Habitat fragmentation is thought to create a barrier to individual movements particularly for are... more Habitat fragmentation is thought to create a barrier to individual movements particularly for area-sensitive species which, by definition, prefer to breed in large tracts of forest. For two breeding seasons, we radio-tracked an area-sensitive species, the scarlet tanager Piranga olivacea, in a fragmented landscape in northeastern PA. We found that scarlet tanagers made extensive and frequent movements among fragments. Paired males were less likely to leave their capture fragment, and traveled shorter distances. Unpaired males in fragments had two distinct tactics we labeled: ''Sedentary'' and ''Mobile''. Sedentary males stayed at one fragment and sang at high rates, while mobile males spent 58% of the total time tracked off their capture fragment and traveled over a kilometer away from the capture site over open fields and through forests. Mobile males were not floaters per se because they were territorial (i.e., singing) in multiple sites. Habitat structure of a fragment did not correlate with the percent time a male spent off the capture fragment. Males in fragments experienced lower pairing success and were more likely to be first time breeders compared to males in continuous forest. Our results suggest that movements by scarlet tanagers in fragmented landscapes are not restricted during the breeding season, and that these movements are related directly to pairing status and indirectly to population density.
ABSTRACT.-We quantified breeding parameters of Crested Auklets (Aethia cristatella) at Buldir and... more ABSTRACT.-We quantified breeding parameters of Crested Auklets (Aethia cristatella) at Buldir and Kasatochi islands in the Aleutian Islands, Alaska, in 1996 and 1997. Crested Auk- lets incubated their eggs for about 36 days and chicks weighed about 35 g within the first three days of ...
Using temperature loggers and radio telemetry, foraging and brooding behaviors of female and male... more Using temperature loggers and radio telemetry, foraging and brooding behaviors of female and male Thick-billed Murres (Uria lomvia) were measured during chick rearing at the Gannet Islands, Labrador, to quantify parental roles during this crucial stage of reproduction. We recorded 2,725 foraging dives by 10 females and 7 males during 1,416 bird-hours of monitoring. Our study birds made between 21 and 107 dives per day between 0327 and 2220 hours, with 54% of females' dives and Ͻ1% of males' dives occurring in conditions of low illumination between sunset and sunrise. Males foraged mostly at midday and, overall, made longer and presumably deeper dives (mean duration 116.2 Ϯ 37.6 s) than females (mean duration 84.1 Ϯ 46.0 s). The maximum dive duration recorded was 240 s. Final dives of foraging trips were inferred to include dives during which chick meals (ϳ95% by number daubed shanny [Lumpenus maculatus]) were obtained. Those dives (mean duration 134.0 Ϯ 36.1 s) and dives in final diving bouts prior to return to the breeding site (mean duration 139.1 Ϯ 40.2 s) averaged longer than other dives, and longer in males than in females, but there was no difference between the sexes in their daily frequency. The modal travel time from the last dive in a feeding trip to arrival at the breeding site was 8 min (no difference between sexes), which represents a maximum travel distance at 65 km h Ϫ1 of 8.7 km, suggesting that foraging occurred close to the colony. Females spent 9 h day Ϫ1 (38% of day, mostly diurnal brooding) at breeding sites whereas males spent 16 h (67% of day, mostly nocturnal brooding). Taken together, these data indicated drastic differences in patterns of foraging and brooding behavior between male and female Thick-billed Murres, but suggest that individual and intercolony variation were also significant. RÉ SUMÉ .-À l'aide d'un enregistreur automatique de température et de la radio-télémétrie, les comportements de recherche alimentaire et d'élevage chez la femelle et le mâle du Guillemot de Brü nnich (Uria lomvia) ont été mesurés au cours de l'élevage des jeunes aux Gannet Islands, Labrador, pour quantifier le rô le des parents au cours de cette étape crucial de la reproduction. Nous avons enregistré 2,725 plongées de quête alimentaire par 10 femelles et 7 mâ les au cours de 1,416 heures-oiseau de suivi. Les oiseaux étudiés ont effectué entre 21 et 107 plongées par jour entre les heures 0327 et 2220, avec 54% de plongées pour les femelles et Ͻ1% de plongées pour les mâles qui se sont déroulées dans des conditions de faible luminosité entre le lever et le coucher du soleil. Les mâ les recherchaient de la nourriture essentiellement en milieu de journée et, le plus important, ils effectuaient des plongées plus longues et vraisemblablement plus profondes (durée moyenne 116.2 Ϯ 37.6 s) que les femelles (durée moyenne 84.1 Ϯ 46.0 s). La durée de plongée maximale enregistrée a été de 240 s. Lors de la recherche alimentaire, les plongées finales ont été inférées pour inclure les plongées destinées au nourrissage des jeunes (ϳ95% de Lompénie tachetée [Lumpenus maculatus] en nombre). Ces plongées (durée moyenne 134.0 Ϯ 36.1 s) et les plongées précédent le retour au site de nidification (durée moyenne 139.1 Ϯ 40.2 s) étaient plus longues en moyenne que les autres plongées. Elles étaient également plus long pour les mâ les que pour les femelles, mais il n'y avait pas de différence entre les sexes dans leur fréquence journalière. 4
2013. Mortality of migratory birds from marine commercial fisheries and offshore oil and gas prod... more 2013. Mortality of migratory birds from marine commercial fisheries and offshore oil and gas production in Canada. Avian Conservation and Ecology 8(2): 4. http://dx.
ABSTRACT: This review paper identifies the main effects of oil and gas drilling waste on benthic
... more ABSTRACT: This review paper identifies the main effects of oil and gas drilling waste on benthic
environments. We identified 26 papers and technical reports that surveyed sediment samples from
72 production or exploration platform sites to assess the zone of influence of sediment contamina-
tion and biological effects on benthic communities. While oil-based fluids are now rarely used in
the marine context, their release has had large-scale (out to 6 km) and persistent (decadal time
scale) impacts on benthic communities. The zone of influence of water-based drilling fluids as
determined by sediment barium concentration was larger (2 to 20 km) than for synthetic-based
fluids (200 to 2000 m). The zone of biological effects on benthic community diversity and abun-
dance ranged from 100 to 1000 m for both water and synthetic fluids. Effects include changes in
benthic species diversity, abundance and alterations to community structure. Functional changes
included a loss of suspension-feeding species and increases in deposit feeders and polychaetes. In
general, this review demonstrates a loss of benthic biodiversity and suspension-feeding commu-
nities due to oil exploration and production and the potential for large-scale effects on sensitive
communities such as deep-sea, coral and vegetated habitats. Current research gaps and priorities
are identified.
Habitat fragmentation is thought to create a barrier to individual movements particularly for are... more Habitat fragmentation is thought to create a barrier to individual movements particularly for area-sensitive species which, by definition, prefer to breed in large tracts of forest. For two breeding seasons, we radio-tracked an area-sensitive species, the scarlet tanager Piranga olivacea, in a fragmented landscape in northeastern PA. We found that scarlet tanagers made extensive and frequent movements among fragments. Paired males were less likely to leave their capture fragment, and traveled shorter distances. Unpaired males in fragments had two distinct tactics we labeled: ''Sedentary'' and ''Mobile''. Sedentary males stayed at one fragment and sang at high rates, while mobile males spent 58% of the total time tracked off their capture fragment and traveled over a kilometer away from the capture site over open fields and through forests. Mobile males were not floaters per se because they were territorial (i.e., singing) in multiple sites. Habitat structure of a fragment did not correlate with the percent time a male spent off the capture fragment. Males in fragments experienced lower pairing success and were more likely to be first time breeders compared to males in continuous forest. Our results suggest that movements by scarlet tanagers in fragmented landscapes are not restricted during the breeding season, and that these movements are related directly to pairing status and indirectly to population density.
We investigated patterns of variation of feather and bill ornaments of Crested Auklets Aethia cri... more We investigated patterns of variation of feather and bill ornaments of Crested Auklets Aethia cristatella, a monogamous seabird, based on 963 individuals measured in the years 1990 to 1998. Three prominent ornaments were displayed: a forehead crest, composed of 11 -31 curved feathers averaging about 40 mm in length, bilaterally symmetrical white auricular plumes on the sides of the head behind the eyes, averaging about 30 mm in length, and brightly coloured semi-circular rictal plates at the corners of the bill. As in other putative sexually selected traits, auklet ornaments were more variable across individuals than non-ornamental traits. Crest length and auricular plume length were positively correlated within individuals but not across years. Among the traits measured there was evidence for slight sexual dimorphism for the auricular plume and rictal plate ornaments and for culmen length and tarsus (males were slightly larger than females) but not for the crest ornament. Breeding adult females and males had greater crest and plume ornament expression than non-breeding adults. Paradoxically, females' crests and rictal plates were more variable than males' crests and rictal plates. Based on independent samples, the expression of feather ornaments and rictal plate varied among years between 1990 and 1998. Crested Auklet ornaments did not vary in concert with the ornaments of Whiskered Aethia pygmaea and Least Auklets Aethia pusilla during this period. Crested Auklet subadults had smaller ornaments than adults. Based on adults remeasured after an interval of one to seven years, the size of individuals' feather ornaments increased with age. We found no relationship between auricular plume length and asymmetry. Male auricular plumes and female crests were weakly correlated with body condition.
2013. Mortality of migratory birds from marine commercial fisheries and offshore oil and gas prod... more 2013. Mortality of migratory birds from marine commercial fisheries and offshore oil and gas production in Canada. Avian Conservation and Ecology 8(2): 4. http://dx.
ABSTRACT During the last 25 years, North America has experienced a significant increase in Double... more ABSTRACT During the last 25 years, North America has experienced a significant increase in Double-crested Cormorants (Phalacrocorax auritus). The increase has caused concern among wildlife and fisheries managers dealing with the perceived and/or real impacts of this bird on fisheries. Cormorant foraging and breeding ecology were examined at a large (&gt;6,000 pairs), unmanaged colony in Lake Ontario, Canada. Chick diet, feeding rates and productivity were evaluated during 2006 and 2007. In 2007, the proportion of adult cormorants making long-range foraging trips (more than ten kilometers) during different stages of the breeding season was estimated. Alewife (Alosa pseudoharengus) composed greater than 86% of chick diet by mass during both years; suggesting that cormorants did not often prey on sport fish for feeding chicks. Chicks were fed approximately 4.5 times per day in 2006, which was significantly lower than 5.9 feeds per day during 2007. Productivity was high in both years, with 2.2 and 1.9 chicks produced per nest in 2006 and 2007, respectively. The decrease in productivity corresponded with an increase in colony size, from 6,125 to 7,241 pairs. In 2007, approximately one-fifth of the nesting colony foraged at least ten kilometers throughout the breeding season. Cormorants fed their chicks very few sport fish in the Toronto area; however, more work is required to determine whether the consumption of Alewife by cormorants represents competition with sport fish for prey.
Journal of Environmental Assessment Policy and Management, 2008
The Environmental Assessment (EA) process should involve the generation of testable predictions g... more The Environmental Assessment (EA) process should involve the generation of testable predictions generated using clearly stated methods and followed by the collection of environmental monitoring data. Follow-up programs should aim to determine the accuracy of the initial predictions. We examined the follow-up process for six oil and gas extraction projects in eastern Canada with respect to assessing batch spill (< 50 barrels of hydrocarbons and synthetic hydrocarbons) predictions. For three projects we compared oil spill frequency predictions to observed data. All three projects exceeded their predicted frequencies and two projects by ratios (actual to predicted) greater than six. Spill histories from earlier projects, clearly exceeding predictions of future projects, are not provided in subsequent oil and gas EAs for the region, when there were opportunities to do so. We provide recommendations on how to strengthen the quality of EAs and increase protection of the marine environment in Canada.
We investigated patterns of variation of feather and bill ornaments of Crested Auklets Aethia cri... more We investigated patterns of variation of feather and bill ornaments of Crested Auklets Aethia cristatella, a monogamous seabird, based on 963 individuals measured in the years 1990 to 1998. Three prominent ornaments were displayed: a forehead crest, composed of 11 -31 curved feathers averaging about 40 mm in length, bilaterally symmetrical white auricular plumes on the sides of the head behind the eyes, averaging about 30 mm in length, and brightly coloured semi-circular rictal plates at the corners of the bill. As in other putative sexually selected traits, auklet ornaments were more variable across individuals than non-ornamental traits. Crest length and auricular plume length were positively correlated within individuals but not across years. Among the traits measured there was evidence for slight sexual dimorphism for the auricular plume and rictal plate ornaments and for culmen length and tarsus (males were slightly larger than females) but not for the crest ornament. Breeding adult females and males had greater crest and plume ornament expression than non-breeding adults. Paradoxically, females' crests and rictal plates were more variable than males' crests and rictal plates. Based on independent samples, the expression of feather ornaments and rictal plate varied among years between 1990 and 1998. Crested Auklet ornaments did not vary in concert with the ornaments of Whiskered Aethia pygmaea and Least Auklets Aethia pusilla during this period. Crested Auklet subadults had smaller ornaments than adults. Based on adults remeasured after an interval of one to seven years, the size of individuals' feather ornaments increased with age. We found no relationship between auricular plume length and asymmetry. Male auricular plumes and female crests were weakly correlated with body condition.
Habitat fragmentation is thought to create a barrier to individual movements particularly for are... more Habitat fragmentation is thought to create a barrier to individual movements particularly for area-sensitive species which, by definition, prefer to breed in large tracts of forest. For two breeding seasons, we radio-tracked an area-sensitive species, the scarlet tanager Piranga olivacea, in a fragmented landscape in northeastern PA. We found that scarlet tanagers made extensive and frequent movements among fragments. Paired males were less likely to leave their capture fragment, and traveled shorter distances. Unpaired males in fragments had two distinct tactics we labeled: ''Sedentary'' and ''Mobile''. Sedentary males stayed at one fragment and sang at high rates, while mobile males spent 58% of the total time tracked off their capture fragment and traveled over a kilometer away from the capture site over open fields and through forests. Mobile males were not floaters per se because they were territorial (i.e., singing) in multiple sites. Habitat structure of a fragment did not correlate with the percent time a male spent off the capture fragment. Males in fragments experienced lower pairing success and were more likely to be first time breeders compared to males in continuous forest. Our results suggest that movements by scarlet tanagers in fragmented landscapes are not restricted during the breeding season, and that these movements are related directly to pairing status and indirectly to population density.
ABSTRACT.-We quantified breeding parameters of Crested Auklets (Aethia cristatella) at Buldir and... more ABSTRACT.-We quantified breeding parameters of Crested Auklets (Aethia cristatella) at Buldir and Kasatochi islands in the Aleutian Islands, Alaska, in 1996 and 1997. Crested Auk- lets incubated their eggs for about 36 days and chicks weighed about 35 g within the first three days of ...
Using temperature loggers and radio telemetry, foraging and brooding behaviors of female and male... more Using temperature loggers and radio telemetry, foraging and brooding behaviors of female and male Thick-billed Murres (Uria lomvia) were measured during chick rearing at the Gannet Islands, Labrador, to quantify parental roles during this crucial stage of reproduction. We recorded 2,725 foraging dives by 10 females and 7 males during 1,416 bird-hours of monitoring. Our study birds made between 21 and 107 dives per day between 0327 and 2220 hours, with 54% of females' dives and Ͻ1% of males' dives occurring in conditions of low illumination between sunset and sunrise. Males foraged mostly at midday and, overall, made longer and presumably deeper dives (mean duration 116.2 Ϯ 37.6 s) than females (mean duration 84.1 Ϯ 46.0 s). The maximum dive duration recorded was 240 s. Final dives of foraging trips were inferred to include dives during which chick meals (ϳ95% by number daubed shanny [Lumpenus maculatus]) were obtained. Those dives (mean duration 134.0 Ϯ 36.1 s) and dives in final diving bouts prior to return to the breeding site (mean duration 139.1 Ϯ 40.2 s) averaged longer than other dives, and longer in males than in females, but there was no difference between the sexes in their daily frequency. The modal travel time from the last dive in a feeding trip to arrival at the breeding site was 8 min (no difference between sexes), which represents a maximum travel distance at 65 km h Ϫ1 of 8.7 km, suggesting that foraging occurred close to the colony. Females spent 9 h day Ϫ1 (38% of day, mostly diurnal brooding) at breeding sites whereas males spent 16 h (67% of day, mostly nocturnal brooding). Taken together, these data indicated drastic differences in patterns of foraging and brooding behavior between male and female Thick-billed Murres, but suggest that individual and intercolony variation were also significant. RÉ SUMÉ .-À l'aide d'un enregistreur automatique de température et de la radio-télémétrie, les comportements de recherche alimentaire et d'élevage chez la femelle et le mâle du Guillemot de Brü nnich (Uria lomvia) ont été mesurés au cours de l'élevage des jeunes aux Gannet Islands, Labrador, pour quantifier le rô le des parents au cours de cette étape crucial de la reproduction. Nous avons enregistré 2,725 plongées de quête alimentaire par 10 femelles et 7 mâ les au cours de 1,416 heures-oiseau de suivi. Les oiseaux étudiés ont effectué entre 21 et 107 plongées par jour entre les heures 0327 et 2220, avec 54% de plongées pour les femelles et Ͻ1% de plongées pour les mâles qui se sont déroulées dans des conditions de faible luminosité entre le lever et le coucher du soleil. Les mâ les recherchaient de la nourriture essentiellement en milieu de journée et, le plus important, ils effectuaient des plongées plus longues et vraisemblablement plus profondes (durée moyenne 116.2 Ϯ 37.6 s) que les femelles (durée moyenne 84.1 Ϯ 46.0 s). La durée de plongée maximale enregistrée a été de 240 s. Lors de la recherche alimentaire, les plongées finales ont été inférées pour inclure les plongées destinées au nourrissage des jeunes (ϳ95% de Lompénie tachetée [Lumpenus maculatus] en nombre). Ces plongées (durée moyenne 134.0 Ϯ 36.1 s) et les plongées précédent le retour au site de nidification (durée moyenne 139.1 Ϯ 40.2 s) étaient plus longues en moyenne que les autres plongées. Elles étaient également plus long pour les mâ les que pour les femelles, mais il n'y avait pas de différence entre les sexes dans leur fréquence journalière. 4
Uploads
Papers by Gail Fraser
environments. We identified 26 papers and technical reports that surveyed sediment samples from
72 production or exploration platform sites to assess the zone of influence of sediment contamina-
tion and biological effects on benthic communities. While oil-based fluids are now rarely used in
the marine context, their release has had large-scale (out to 6 km) and persistent (decadal time
scale) impacts on benthic communities. The zone of influence of water-based drilling fluids as
determined by sediment barium concentration was larger (2 to 20 km) than for synthetic-based
fluids (200 to 2000 m). The zone of biological effects on benthic community diversity and abun-
dance ranged from 100 to 1000 m for both water and synthetic fluids. Effects include changes in
benthic species diversity, abundance and alterations to community structure. Functional changes
included a loss of suspension-feeding species and increases in deposit feeders and polychaetes. In
general, this review demonstrates a loss of benthic biodiversity and suspension-feeding commu-
nities due to oil exploration and production and the potential for large-scale effects on sensitive
communities such as deep-sea, coral and vegetated habitats. Current research gaps and priorities
are identified.
environments. We identified 26 papers and technical reports that surveyed sediment samples from
72 production or exploration platform sites to assess the zone of influence of sediment contamina-
tion and biological effects on benthic communities. While oil-based fluids are now rarely used in
the marine context, their release has had large-scale (out to 6 km) and persistent (decadal time
scale) impacts on benthic communities. The zone of influence of water-based drilling fluids as
determined by sediment barium concentration was larger (2 to 20 km) than for synthetic-based
fluids (200 to 2000 m). The zone of biological effects on benthic community diversity and abun-
dance ranged from 100 to 1000 m for both water and synthetic fluids. Effects include changes in
benthic species diversity, abundance and alterations to community structure. Functional changes
included a loss of suspension-feeding species and increases in deposit feeders and polychaetes. In
general, this review demonstrates a loss of benthic biodiversity and suspension-feeding commu-
nities due to oil exploration and production and the potential for large-scale effects on sensitive
communities such as deep-sea, coral and vegetated habitats. Current research gaps and priorities
are identified.