Author(s): Eiji Yauchi; Kazuhisa Onodera; Maiko Motonaga
Linked Author(s): Eiji Yauchi
Keywords: Tideland; Nutrient load; Bird feces; Tokyo Bay
Abstract: The Yatsu Higata wetland area is one of the most significant tidal flat areas remaining in Japan. Despite the relatively small size of the area, numerous migratory species visit the wetland to breed and feed. The importance of the site was officially recognized as an important wetland for migratory bird species in 1993 when it was awarded Ramsar status. However, extraordinary growth of Ulva sp. (sea lettuce) in recent years has severely impacted the ecology of the area, causing widespread death of benthic organisms such as clams and sandworms. Extrapolations of the annual increase in the surface area covered by Ulva sp. have raised the possibility that the entire tidal flat area may be covered by this alga in the future. This study sought to determine whether the nutrient loads from migratory bird guano were responsible for the extraordinary growth observed in Ulva sp. using field studies to clarify the nutrient dynamics in an affected area of the tidal flats.
Year: 2010