How important is it at the ecosystem scale?

Coastal seas, tidal flats, and rivers are shaped by many interacting organisms and by the continuous movement of materials such as carbon and nutrients.

We study these processes by asking not only what is happening and why it is happening, but also:

How important is it at the scale of the whole ecosystem?

By quantifying and comparing ecological processes, we can identify what truly supports biological production and material cycling in coastal ecosystems, and which environmental changes have the greatest consequences.

Ultimately, we aim to use this understanding to contribute to the conservation, restoration, and sustainable use of coastal ecosystems.

Our Approach

Observation → Mechanism → Ecosystem-scale significance

Suppose we observe fish digging into the sediment of a tidal flat.

Rather than simply documenting the behavior, we ask:

• Why does this behavior occur?

• Which fish species are responsible, and how much sediment do they disturb?

• What percentage of the entire tidal flat is disturbed each day?

Similarly, when nutrients are supplied to coastal waters by submarine groundwater discharge, we ask:

• Where do the nutrients come from, and how much is supplied?

• Which organisms use them?

• What proportion of the total nutrient supply to the coastal ecosystem do they represent?

Our goal is not simply to measure individual organisms, sites, or processes.

We aim to scale these observations up to populations, tidal flats, bays, and entire coastal ecosystems, and to express their importance in ways that can be compared and intuitively understood.

This helps provide a scientific basis for deciding what should be protected, where restoration may be most effective, and which environmental changes deserve priority.

Research Questions Come First

Our research is not restricted to particular organisms, habitats, or techniques.

We study a wide range of components of coastal ecosystems, including nutrients and organic matter, phytoplankton, microphytobenthos, seaweeds, bivalves, fish, and birds.

Our field sites are equally diverse, extending from dams and rivers to groundwater systems, tidal flats, seagrass and seaweed beds, enclosed bays, and coastal waters influenced by the open ocean.

To address these questions, we have gradually expanded our research toolkit through our work. Depending on the question, we use approaches such as:

• field observations and experiments

• stable isotope analysis

• environmental DNA (eDNA)

• moored environmental sensors

• fixed cameras

• drones

• satellite remote sensing

• programming, statistics, and spatial analysis

Using a new technique is never the goal in itself.

We begin with the question:

What do we want to understand?

and then choose or develop the approaches needed to answer it.

Main Research Fields

Our major field sites extend from the upper Midori River and its estuary to Minamata and the Yatsushiro Sea, and further south to Kagoshima Bay.

Although these environments differ greatly, our underlying perspective remains the same: we seek to understand ecological processes within the context of the whole ecosystem.

Learn More

Research

Explore our research questions, current projects, and the ecological processes we study.

Members

Meet the faculty and students working in the laboratory and learn about their research interests.

Publications

Browse our peer-reviewed papers, presentations, research grants, and other academic activities.

Contact

Marine Ecology Laboratory
Faculty of Environmental and Symbiotic Sciences
Prefectural University of Kumamoto

Tomohiro Komorita
Associate Professor

Email: komorita [at] pu-kumamoto.ac.jp