Research on seabird

토픽 개요

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  • Prof. Watanuki's Laboratory of Marine Bioresource Science, Division of Marine Bioresource and Environmental Science 포럼
  • Prof. Yutaka Watanuki 웹페이지
  • About the copyright 웹페이지
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  Seabirds traveling between the Arctic and Antarctica

  • Changes in the food and distribution of marine birds can be a useful alternative indicator of the impact of climate change on marine ecosystems in areas without fisheries information. How does ecosystems change according to the depletion of sea ice in the polar regions and how does seabirds respond to this change? We found that the short-tailed shearwaters moved to the Chukchi Sea through the Bering Strait in late summer. This Chukchi must be important feeding area to store energy before the migration to the south. A study by Oshoromaru, ArCS project, showed that the krill, the main diet of shearwaters, was smaller in summer but grew to a few millimeters in autumn to be suitable size for shearwaters.

    
    

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  Long-Term Changes in Marine Ecosystems from Seabirds

  • Marine birds can be a good monitor of the changes in global marine ecosystems. Surveys of marine birds are cheaper and easier than surveys by vessels. Seabirds are marine top predators ranging widely  and thus provides a comprehensive and useful indicator of a broad range of ecosystems. Rhinoceros Auklet is a seabird that breeds at mid-and high latitudes in the North Pacific, burrowing and nesting on isolated islands, diving to a depth of several tens of metres, and feed on forage fish. Parents return to the islands at night. We have monitored food and chick growth for more than 30 years on Teuri Island locating in the Sea of Japan in Hokkaido. We found that the chicks  grew better when they were fed with sardines and sand lance in the cold period in the 1980s and anchovy during the warm period in the 1990s. However, after 2014, the juvenile greenling was main prey species, and the chick growth and fledging success were poor. These food switching have been associated with meso-scale climate change, i.e. regime shifts. In addition, after 2018, the birds began to eat the sand lance again. It may be returning to the cold season. Thus our study indicates that marine birds may signal a major shift in marine ecosystems in advance.
    

    
    

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  Marine plastics and their effects on seabirds

  • About 400 million tons of plastic are produced each year and nearly 10 million tons are discharged into the ocean. The incidence of plastics in the stomach of seabirds has increased year by year since it was reported in the 1960s. The incidence in the Northern Fulmar increased between the 1970s and the 2000s in the North Atlantic  and between the early 2000 and 2008 in the Arctic. Most individuals of this species now have plastics in their stomach. The effect of plastics ingested by seabirds is not well understood. A review of previous studies on the effects of plastic indicates that the effects are likely if the mass of ingested plastic  is 0.25% or more of body weight. We are conducting an outdoor plastic feeding experiment using seabird chicks.

    
    

    
    

  • Watanuki, 2019, Kagaku URL

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