Research at a glance(研究の様子)

There are numerous seaweed and seagrass communities found from the intertidal zone to depths exceeding 100m. Our laboratory utilizes various methods and equipment to elucidate the biodiversity, ecology, and ecophysiology of marine plants.

Filed Survey using SCUBA
Field survey in Kuchinoerabu I.
Field surveys using SCUBA require sets of equipment including air compressors, boats, cameras, and video cameras, all of which our lab possesses. Students who wish to study using SCUBA must obtain both a national license for professional diving from the Japanese Government and a private SCUBA license. For undergraduate students, we recommend taking a class in Scientific Diving (Department of Fisheries, 2 credits) to obtain the national license.

Line-Transect Method
Line-Transect survey
The line-transect survey is conducted to elucidate the community structure of seaweed and seagrass. These communities are known to vary based on depth, substratum, waves, and other factors. The line is typically around 200m long, but we occasionally extend it to 800m. At regular intervals on the line, we record species composition, coverage, substratum, temperature, depth, and other factors, as well as take pictures and videos. In Kagoshima, we can observe typical spatial variations of Sargassum, Eckonia, Undaria, and other species.

Phenology and Production surveys
Field surveys conducted almost monthly are necessary to elucidate the life history, reproduction, and production (or standing crop) of seaweed and seagrass communities. These surveys provide insights into seasonal changes, maturation periods, and biomass, among other things. Quadrat sampling is frequently used to estimate and monitor community biomass.

Measurement of temperature, salinity, light Intensity and other environmental factors
Environmental factors, including water temperature, salinity, and light intensity, are always measured in the field. Portable equipment is a powerful tool for these measurements. For long-term measurements of temperature and light in the community, we also deploy data loggers at the depth of the seaweed community. Portable CTDs or tachometers are sometimes used.

Measurement of nutrients and chlorophyll
Nutrients are essential for the existence of seaweed and seagrass communities. Our lab uses two types of spectrophotometers (HACH DR5000 and DR2700) to measure dissolved inorganic nitrogen (DIN: NO3-N, NO-2N, NH4-N) and phosphate (PO4-P). The latter equipment can operate on batteries, enabling us to measure it at the study site. We also use it for measuring chlorophyll a and c.

Identification of Seaweed

Identification of algae
Samples are sometimes collected during surveys to identify specific seaweed species. In the lab, we observe the outer and inner structure of algae to identify it, and specimens are deposited in the herbarium. Our lab possesses various types of microscopes, including the Nikon 80i DIC microscope, SMZ1500, and SMZ1000 stereoscopic microscope.

Taxonomy or Phylogeographic Study

Astec GeneAtlas
We are focusing on some groups of algae through morphological and molecular phylogenetic studies as the taxonomy of algae still poses some problems, especially in tropical species.特定のグループを対称として、分類の再検討や系統関係に関する研究をおこなうこともあります。DNAを抽出して分子系統解析をおこない、系統関係について明らかにします。

Microscopic observation by Table-Top SEM

Surface view of the coralline alga
Our lab possesses various types of microscopes, including the TableTop SEM (HITACHI TM-1000). TM-1000 is an excellent imaging platform for labs requiring higher resolution and deeper focus depth, and it requires no electron microscopical technical skills or sample preparation techniques.


Measurement of Photosynthetic activity

YSI #5100
Our lab uses dissolved oxygen probes to measure the photosynthetic performance of seaweeds at various temperatures and light treatments. Photosynthetic activities serve as an excellent indicator to consider temperature and light tolerance in the natural habitat.


Pulse fluorometry
Our lab possesses two types of PAM equipment for laboratory and underwater use, which we use to measure coral, algae, and seagrass.


Culture experiment

Incubators EYELA MTI201
A culture experiment is a valuable tool for understanding the life history and growth characteristics of a particular organism. Although establishing an in vitro culture can be challenging, anyone can do it with proper training and knowledge of the protocols. Our laboratory has multiple incubators, including EYELA's MTI201 incubator, which has five individual chambers equipped with thermostats. With this equipment, we can conduct culture experiments at five different temperatures simultaneously while maintaining consistent lighting conditions. In fact, we have four sets of MTI201 incubators available in our lab.

Research Voyage by T/S Nanseimaru

Kagoshima University, one of Japan's five national fisheries universities, owns two research and training vessels. In the 1950s through the 1970s, Drs. Tanaka and Itono conducted numerous surveys using dredges, resulting in the discovery of many new species. Recently, we have restarted this survey using both dredges and ROVs.