Estimation of Groundwater-Derived Nutrient Inputs into the West Coast of Ariake Bay

DOI Web Site

Bibliographic Information

Other Title
  • 有明海西岸域への地下水由来の栄養塩供給量の評価
  • アリアケカイ セイガンイキ エ ノ チカスイ ユライ ノ エイヨウエン キョウキュウリョウ ノ ヒョウカ

Search this article

Abstract

Terrestrial freshwater and associated nutrient fluxes affect primary production in coastal areas. In contrast to river water like the Chikugo River, however, the contribution of groundwater discharge to the coastal ecosystem has not been well evaluated in Ariake Bay. In this study, 222Rn was considered as a good indicator of groundwater because 222Rn concentrations in groundwater along the west coast of Ariake Bay were one or three orders of magnitude higher than those in river water. 222Rn distribution standardized on the basis of accumulated rainfall and water depth at the sampling location successfully indicated the spatial variation of groundwater discharge. Furthermore, total groundwater fluxes were evaluated from the 222Rn distributions because spatial distributions of 222Rn were correlated with actual groundwater fluxes measured at five different locations. Nutrient fluxes through the groundwater discharge also had spatial variation : 7．8to510kg−N day－1 for DIN（dissolved inorganic nitrogen）and 0．4 to 3．9kg−P day－1 for DIP（dissolved inorganic phosphorus）, with the maximum values in the Shimabara area, where both groundwater fluxes and nutrient concentrations in groundwater were highest. Along the west coast of Ariake Bay, where there are no big rivers, groundwater can be an important nutrient source to enhance primary production, resulting in good food sources for bivalves and blooming of green macroalgae.

Journal

  • Bulletin on Coastal Oceanography

    Bulletin on Coastal Oceanography 50 (2), 157-167, 2013

    Coastal Oceanography Research Committee, the Oceanographic Society of Japan

Related Projects

See more

Keywords

Details 詳細情報について

Report a problem

Back to top