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| Cury, Philippe; Boyd, Ian L.; Bonhommeau, Sylvain; Anker-nilssen, Tycho; Crawford, Robert J. M.; Furness, Robert W.; Mills, James A.; Murphy, Eugene J.; Oesterblom, Henrik; Paleczny, Michelle; Piatt, John F.; Roux, Jean-paul; Shannon, Lynne; Sydeman, William J.. |
| Determining the form of key predator-prey relationships is critical for understanding marine ecosystem dynamics. Using a comprehensive global database, we quantified the effect of fluctuations in food abundance on seabird breeding success. We identified a threshold in prey (fish and krill, termed "forage fish") abundance below which seabirds experience consistently reduced and more variable productivity. This response was common to all seven ecosystems and 14 bird species examined within the Atlantic, Pacific, and Southern Oceans. The threshold approximated one-third of the maximum prey biomass observed in long-term studies. This provides an indicator of the minimal forage fish biomass needed to sustain seabird productivity over the long term. |
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| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00056/16770/14307.pdf |
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| De Ruiter, Stacy; Boyd, Ian L.; Claridge, Diane E.; Clark, Christopher W.; Gagnon, Chuck; Southall, Brandon L.; Tyack, Peter L.. |
| In 2007 and 2008, controlled exposure experiments were performed in the Bahamas to study behavioral responses to simulated mid-frequency active sonar (MFA) by three groups of odontocetes: false killer whales, Pseudorca crassidens; short-finned pilot whales, Globicephala macrorhynchus; and melon-headed whales, Peponocephala electra. An individual in each group was tagged with a Dtag to record acoustic and movement data. During exposures, some individuals produced whistles that seemed similar to the experimental MFA stimulus. Statistical tests were thus applied to investigate whistle-MFA similarity and the relationship between whistle production rate and MFA reception time. For the false killer whale group, overall whistle rate and production rate of the... |
| Tipo: Text |
Palavras-chave: Noise; Sonar; Mid-frequency sonar; Whistle; Behavioral effects; Sound production; Pseudorca crassidens; Globicephala macrorhynchus; Peponocephala electra; False killer whale; Pilot whale; Melon-headed whale. |
| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00138/24974/23185.pdf |
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