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Environment Research and Technology Development Fund S-13 Development of Coastal Management Method to Realize the Sustainable Coastal SeaEnvironment Research and Technology Development Fund S-13 Development of Coastal Management Method to Realize the Sustainable Coastal Sea

Home » Objectives » Topic 1:Development of methods for managing nutrient concentrations in the Seto Inland Sea (enclosed coastal sea)

Topic 1Development of methods for managing nutrient concentrations in the Seto Inland Sea (enclosed coastal sea)

Outline

Efforts are currently underway to expand the present uniform method of water quality management in the Seto Inland Sea to bay and open sea management that takes into consideration social and geopolitical characteristics and seasonal fluctuations, and to preserve and restore nutrient management and biological habitat environments, in order to develop highly sustainable coastal management methods with the aim of achieving healthy substance circulation and high biological productivity that are not impaired by red tides or the like.

Topic Leader Wataru Nishijima (Professor and Director, Environmental Research and Management Center, Hiroshima University)

Subtopic (1) Development of methods for managing nutrient concentrations

Description of Research (FY 2014 – 2015 Achievements)

While narrowing down the target ocean regions for research and conducting verifications such as identifying and resolving issues with research locations, methods, topics etc., we performed biological research into nutrient salts, phytoplankton and zooplankton, sand eels, anchovies and other sea creatures that feed on plankton and so on, in order to determine the current state of water quality and ocean life. We also studied transparency and light attenuation and prepared the basic framework for numerical models for each ocean region. We expanded the target ocean regions for research and studied nutrient salts and biological organisms in order to determine the current state of water quality and ocean life. In addition, we worked to analyze the structure of the ecosystem in Hiroshima Bay. We determined that differences between the bay and the open ocean and seasonal changes were factors that cause light attenuation.

Description of Research (FY 2016 Plan)

(1) Based on both accumulated data and ongoing research, we will analyze the structure of the ecosystem as revealed by the transfer efficiency in each bay and open sea region, and identify sand eel spawning grounds and determine their environmental status, in order to determine the stocks and state of reproduction of the fish species that play a crucial role in the overall ecosystem of the Seto Inland Sea.

Subtopic Leader Wataru Nishijima (Professor and Director, Environmental Research and Management Center, Hiroshima University)

Subtopic (2) Determination of the function of tidal flats and seaweed beds in nutrient circulation and biological reproduction

Description of Research (FY 2014 – 2015 Achievements)

(2) We measured the nutrient salt concentration in tidal flats and seaweed beds to estimate the inflow and outflow of the substances that become nutrient salts, in order to gather basic data on periphytic algae. We also conducted a spatial assessment of tidal flats and seaweed beds in order to study differences in functions due to ground height and the like.

Description of Research (FY 2016 Plan)

(2) We will continue to conduct year-round observations and continuous measurements during the tides. For Zostera beds, we will study not only carbonic acid and the like but also the light environment to make a quantitative assessment of primary production activity. At tidal flats, we will measure nutrient salt and carbonic acid concentrations in seawater over time and collect data on the spatial distribution of periphytic algae quantities at the surface of the tidal flats.

Subtopic Leader Kuninao Tada (Professor, Department of Agriculture, Kagawa University)