Assimilation efficiency of adult Kittiwakes and Br�nnich's Guillemots fed Capelin and Arctic Cod

Brekke, Bente; Gabrielsen, Geir Wing

doi:10.1007/bf00239177

Cited by 81 publications

(64 citation statements)

References 28 publications

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“…The nesting period for little auks lasts about 28 days (Gaston and Jones 1998;Stempniewicz 2001;Strøm 2005), whereas for Brunnich's guillemots and kittiwakes, it lasts 20-22 and 35-40 days, respectively (Brekke and Gabrielsen 1994;Strøm 2005). These two colonies studied were similar in size, numbering around ten thousand breeding pairs each (Stempniewicz 1992;Isaksen 1995).…”

Section: Discussionmentioning

confidence: 99%

“…These two colonies studied were similar in size, numbering around ten thousand breeding pairs each (Stempniewicz 1992;Isaksen 1995). Little auks, guillemots, and kittiwakes differ in body mass (kittiwake: 366 ± 35 g, Brunnich's guillemot: 967 ± 54 g, little auk: 163 ± 11 g; Brekke and Gabrielsen 1994;Gaston and Jones 1998;Stempniewicz 2001;Strøm 2005) and almost certainly produce different amounts of guano per day. Despite this, the median rates of guano deposition (dry mass g m -2 day -1 ) on tundra adjacent to the two colonies were similar.…”

Section: Discussionmentioning

confidence: 99%

“…Guillemots and kittiwakes feed mainly on fish, such as polar cod (Boreogadus saida) and capelin (Mallotus villosus) (Brekke and Gabrielsen 1994;Mehlum et al 1998;Mehlum 2001). These seabirds also differ in their typical behavior while on or over land, with little auks spending more time circling over and around the colony, and thereby likely to influence a different area of tundra to guillemots and kittiwakes (Stempniewicz et al 2007).…”

Section: Introductionmentioning

confidence: 99%

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Guano deposition and nutrient enrichment in the vicinity of planktivorous and piscivorous seabird colonies in Spitsbergen

et al. 2012

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The crucial role of seabirds in the enrichment of nutrient-poor polar terrestrial ecosystem is well-known. However, no studies have examined the potentially different impacts associated with piscivorous and planktivorous bird colonies on the surrounding tundra soils. Therefore, we compared guano deposition and physical and chemical parameters of soil near two large seabird colonies, one of planktivorous little auks (Alle alle) and the other comprising piscivorous Brunnich's guillemots (Uria lomvia) and kittiwakes (Rissa tridactyla). The two colonies generated similar levels of guano deposition, with the intensity of deposition decreasing away from the colony. Guano deposition adjacent to both colonies was considerably higher than that in control areas. The increased guano supply around colonies significantly enhanced soil conductivity, nitrogen (NO 3 -, NH 4 ? ), potassium (K ? ), and phosphate (PO 4 3-) ion concentrations and led to reduced pH values. Guano deposition explained 84 % (piscivorous colony) and 67 % (planktivorous colony) of the total variation in the tested soil parameters. Planktivore and piscivore colonies affected adjacent tundra in different ways. The phosphate content and pH value of soil influenced by piscivores were significantly higher than values measured in planktivore-influenced soil. The gradient of guano deposition and associated ion content in the soil decreased more rapidly with distance from the piscivore colony. Climate-induced changes in populations of planktivorous and piscivorous seabirds are expected in the study region and may therefore have substantial consequential effects on Arctic terrestrial ecosystems.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Guano deposition and nutrient enrichment in the vicinity of planktivorous and piscivorous seabird colonies in Spitsbergen

et al. 2012

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“…Increased feeding rate was found to increase the PCB uptake rate constant from food in experimental studies of ringed doves (Streptopelia rissoria) (Drouillard and Norstrom, 2003). In addition, the high lipid contents in calanoid copepods (40% of dry weight, (Scott et al, 1999)) might contribute to elevated PCB concentrations in little auk if the higher assimilation efficiency of lipids than proteins (Brekke and Gabrielsen, 1994) influences the PCB uptake (Gobas et al, 1999). However, the ringed dove study showed that PCB assimilation efficiencies were similar between doves fed a high or a low lipid content diet (Drouillard and Norstrom, 2003).…”

Section: Group Imentioning

confidence: 96%

“…Based on the measured body mass and its species-specific relationship with basal and field metabolic rates (Gabrielsen et al, 1991;Ellis and Gabrielsen, 2002), daily energy requirements were calculated for each seabird species. Given the energy density of the species' prey items in the Barents Sea (Gabrielsen et al, 1991;Gabrielsen and Ryg, 1992) and the assimilation efficiencies of seabirds (Brekke and Gabrielsen, 1994), the respective weight-specific feeding rates were calculated assuming a diet of 100% copepods in little auk, 20% euphausiids, 20% amphipods and 60% polar cod in Bru¨nnich's guillemot, and 100% polar cod in black guillemot and kittiwake, based on previous dietary analysis of these species in the Barents Sea (Lønne and Gabrielsen, 1992;Mehlum and Gabrielsen, 1993;Weslawski et al, 1999).…”

Section: Species and Samplingmentioning

confidence: 99%

Bioaccumulation of PCBs in Arctic seabirds: influence of dietary exposure and congener biotransformation

Borgå¹,

Wolkers²,

Skaare³

et al. 2005

Environmental Pollution

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Four seabird species and their prey (zooplankton or fish) were collected in the Barents Sea to determine how dietary exposure, cytochrome P450 (CYP) enzyme activities and sex influenced their hepatic PCB concentrations and accumulation patterns. Five males and five females from each seabird species (little auk (Alle alle), Bru¨nnich's guillemot (Uria lomvia), black guillemot (Cepphus grylle) and black-legged kittiwake (Rissa tridactyla)) were analysed. PCB concentrations could not be explained directly by carbon source (d 15 N, migratory pattern, age) and contaminant metabolism. Contrary to previous studies, the PCB pattern differed among seabirds, with a higher proportion of persistent congeners (% of PCB-153, R PCB-153 ) in black-legged kittiwake than in auks. The PCB pattern also differed among auks, with little auk as the most efficient biotransformer (highest R PCB-153 values of persistent congeners). Based on high R PCB-153 values, Bru¨nnich's guillemot poorly metabolised ortho-meta-unsubstituted congeners, whereas black guillemot poorly metabolised meta-para unsubstituted congeners. Species-specific differences in PCB biotransformation were confirmed by metabolic indices, where PCB patterns in seabirds were adjusted for PCB pattern in prey. The relative contribution of ortho-meta-unsubstituted congeners to P PCBs decreased with increasing EROD activity. There were no differences in PCB concentrations, PCB patterns or cytochrome P450 enzyme activities between males and females. CYP P450 activities (CYP1A-and CYP2B/3A-like: EROD and testosterone 6b-hydroxylation, respectively) were low and did not correlate with concentrations of non-or mono-ortho Cl-substituted PCBs (NO-and MO-PCBs), or with total toxic equivalent concentrations (TEQs) for dioxin-like effects of NO-and MO-PCBs.

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Ecological constraints on digestive physiology in carnivorous and piscivorous birds

et al. 1999

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Assimilation efficiency of adult Kittiwakes and Br�nnich's Guillemots fed Capelin and Arctic Cod

Cited by 81 publications

References 28 publications

Guano deposition and nutrient enrichment in the vicinity of planktivorous and piscivorous seabird colonies in Spitsbergen

Guano deposition and nutrient enrichment in the vicinity of planktivorous and piscivorous seabird colonies in Spitsbergen

Bioaccumulation of PCBs in Arctic seabirds: influence of dietary exposure and congener biotransformation

Ecological constraints on digestive physiology in carnivorous and piscivorous birds

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