The co-distribution of seabirds and their juvenile fish ...• Simmonds E, MacLennan D (2005)...
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The co-distribution of seabirds and their juvenile fish prey in Baffin Bay Mathieu LeBlanc 1 , Anders Mosbech 2 & Louis Fortier 1 1 Department of Biology, Université Laval, Québec, Canada 2 Department of Bioscience - Arctic Environment, Aarhus University, Roskilde, Denmark [email protected] Materials and methods Preliminary results Conclusions References Acknowledgments Simrad.com Ichthyoplankton net Bottom trawl Midwater trawl Recording of hydroacoustic data Sampling of pelagic fish to validate acoustic echoes a) • The thick-billed murre (n = 3182) was the most abundant bird species encountered. • Arctic cod dominated the age-1+ fish assemblage. • Thick-billed murre and black-legged kittiwake were significantly more abundant on the eastern side of longitude 60°W (p < 0.05, Mann-Whitney U-test). In contrast, the acoustic fish density (NASC) was significantly higher on the western side (p < 2.2e-16, Mann-Whitney U-test). Future work • Finish the processing and analysis of the hydroacoustic data. • Estimate fish abundance and biomass along the transects using the hydroacoustic data. • Verify if there is a correlation between fish and seabirds distribution at different spatial scales. Study area Figure 1. Sampling stations (red dots), acoustic transects (blue line) and mean sea-ice concentration (%) during the GreenEdge 2016 cruise (9 June – 12 July). Figure 2. a) Seabird counts and b) Nautical Area Scattering Coefficient (NASC; acoustic fish density) at 38 kHz within the top 200 m along the transects. We thank the officers and crew of the CCGS Amundsen for their dedication and professionalism. We are grateful to the several technicians and colleagues who contributed to the collection of seabirds observations data, hydroacoustic data and net samples used in the present project. ML benefits from scholarships from the Natural Sciences and Engineering Research Council of Canada (NSERC). Hull-mounted echosounder EK60 (38 and 120 kHz) Simrad.com Context of the study Hypothesis • The abundance and biomass of juvenile fish, especially at the sea-ice edge, influence the distribution and composition of the seabird assemblage. CCGS Amundsen Fishbase.org Arctic cod b) • In arctic marine ecosystems, pelagic fish play a key role by transferring energy from zooplankton to the upper trophic levels, including seabirds. • The interactions between fish and seabirds at the sea-ice edge, an environment increasingly common in the warming Arctic, are poorly documented. Seabird assemblage and distribution From Johansen et al., 2015 Animalia-life.com billbeardcostarica.com Biotope.no fotooizo.free.fr Animalia-life.com 71% 24% 5% Arctic cod Myctophidae Liparidae Figure 3. Age-1+ fish assemblage from net sampling (n = 191). Wildlife observations (for a 2-minute period) • Bradstreet MSW, Cross WE (1982) Trophic relationships at high Arctic ice edges. Arctic:1-12. • Johansen KL, Boertmann D, Mosbech A, Hansen TB (2015) Manual for seabird and marine mammal survey on seismic vessels in Greenland. 4th revised edition. Aarhus University, Danish Centre for Environment and Energy, 74 pp. Scientific Report from Danish Centre for Environment and Energy No. 152. • Simmonds E, MacLennan D (2005) Fisheries Acoustics: Theory and Practice. Oxford: Blackwell Science:437. • Welch HE, Bergmann MA, Siferd TD, Martin KA, Curtis MF, Crawford RE, Conover RJ, Hop H (1992) Energy Flow through the marine ecosystem of the Lancaster Sound Region, Arctic Canada. Arctic 45:343-357. Garde côtière canadienne Northern fulmar Black-legged kittiwake Thick-billed murre Fish Baffin Island Disko Isl. Davis Strait Baffin Bay
Transcript of The co-distribution of seabirds and their juvenile fish ...• Simmonds E, MacLennan D (2005)...
The co-distribution of seabirds and their juvenile fish prey in Baffin BayMathieu LeBlanc1, Anders Mosbech2 & Louis Fortier1
1Department of Biology, Université Laval, Québec, Canada
2Department of Bioscience - Arctic Environment, Aarhus University, Roskilde, Denmark
Materials and methods
Preliminary results
Conclusions
References
Acknowledgments
Simrad.com
Ichthyoplankton net Bottom trawl Midwater trawl
Recording of hydroacoustic data
Sampling of pelagic fish to validate
acoustic echoes
a)
• The thick-billed murre (n = 3182) was the most abundant bird species encountered.
• Arctic cod dominated the age-1+ fish assemblage.
• Thick-billed murre and black-legged kittiwake were significantly more abundant on the eastern side of longitude 60°W
(p < 0.05, Mann-Whitney U-test). In contrast, the acoustic fish density (NASC) was significantly higher on the western
side (p < 2.2e-16, Mann-Whitney U-test).
Future work• Finish the processing and analysis of the hydroacoustic data.
• Estimate fish abundance and biomass along the transects using the hydroacoustic data.
• Verify if there is a correlation between fish and seabirds distribution at different spatial scales.
Study area
Figure 1. Sampling stations (red dots), acoustic transects
(blue line) and mean sea-ice concentration (%) during the
GreenEdge 2016 cruise (9 June – 12 July).
Figure 2. a) Seabird counts and b) Nautical Area Scattering
Coefficient (NASC; acoustic fish density) at 38 kHz within
the top 200 m along the transects.
We thank the officers and crew of the CCGS Amundsen for their dedication and professionalism. We are grateful to the several technicians and colleagues who
contributed to the collection of seabirds observations data, hydroacoustic data and net samples used in the present project. ML benefits from scholarships from the
Natural Sciences and Engineering Research Council of Canada (NSERC).
Hull-mounted echosounder EK60 (38 and 120 kHz)
Simrad.com
Context of the study
Hypothesis
• The abundance and biomass of juvenile fish, especially at the
sea-ice edge, influence the distribution and composition of the
seabird assemblage.
CCGS Amundsen
Fishbase.orgArctic cod
b)
• In arctic marine ecosystems, pelagic fish play a key role by
transferring energy from zooplankton to the upper trophic
levels, including seabirds.
• The interactions between fish and seabirds at the sea-ice edge,
an environment increasingly common in the warming Arctic,
are poorly documented.
Seabird assemblage and distribution
From Johansen et al., 2015
Animalia-life.com
billbeardcostarica.com
Biotope.no
fotooizo.free.fr
Animalia-life.com
71%
24%
5%
Arctic cod Myctophidae Liparidae
Figure 3. Age-1+ fish assemblage from
net sampling (n = 191).
Wildlife observations (for a 2-minute period)
• Bradstreet MSW, Cross WE (1982) Trophic relationships at high Arctic ice edges. Arctic:1-12.
• Johansen KL, Boertmann D, Mosbech A, Hansen TB (2015) Manual for seabird and marine mammal survey on seismic vessels in Greenland. 4th revised edition. Aarhus
University, Danish Centre for Environment and Energy, 74 pp. Scientific Report from Danish Centre for Environment and Energy No. 152.
• Simmonds E, MacLennan D (2005) Fisheries Acoustics: Theory and Practice. Oxford: Blackwell Science:437.
• Welch HE, Bergmann MA, Siferd TD, Martin KA, Curtis MF, Crawford RE, Conover RJ, Hop H (1992) Energy Flow through the marine ecosystem of the Lancaster Sound
Region, Arctic Canada. Arctic 45:343-357.
Garde côtière canadienne
Northern fulmar
Black-legged kittiwake
Thick-billed murre FishBaffin Island
Disko Isl.
Davis Strait
Baffin Bay
