こんにちは！M2のRyuuです！
From September 1 to 10, 2026, I had the opportunity to participate in the KH-26-6 research cruise aboard R/V *Hakuho Maru*, conducting oceanographic observations and sampling in Sagami Bay and Suruga Bay, Japan. As this was my first research cruise, I was both excited and curious about what life and scientific work at sea would be like.
During the cruise, I was mainly involved in seawater sampling using a CTD rosette system, seawater filtration, and sediment sampling with a multicorer.
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| Details of CTD |
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| CTD system |
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| Multicorer for sediment |
The CTD system allows us to measure important oceanographic parameters, such as conductivity, temperature, and depth, while collecting seawater from different depths. During this cruise, we collected water samples from the surface down to approximately 2,000 meters. After each CTD cast, we transferred and filtered the collected seawater for subsequent laboratory analyses, including dissolved organic carbon (DOC) measurements.
Unlike working in a laboratory on land, sampling at sea requires close coordination among researchers, technicians, and crew members. Each sampling operation must be carefully organized, and samples often need to be processed promptly after collection. It was a valuable opportunity for me to experience how oceanographic fieldwork is actually conducted.
One of the most memorable aspects of the cruise was undoubtedly the intense working schedule.
On most days, we woke up around 5:30 a.m. and began CTD operations at 6:00 a.m. After collecting seawater, we spent much of the day processing and filtering samples, sometimes continuing until around 10:00 p.m.
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| Bedroom on Hakuho Maru |
The busiest day was particularly unforgettable. We conducted seven CTD casts in a single day, and the large number of samples kept us working until 2:30 a.m. Despite having only a few hours of rest, we had to get up again at 5:30 a.m. to prepare for the next day's operations. It was exhausting, but it also gave me a much deeper appreciation of the effort behind oceanographic research.
Of course, life aboard the ship was not all about work. The meals were surprisingly good, and the occasional desserts and snacks were always something to look forward to after a long day. I also enjoyed spending time with researchers from different backgrounds, exchanging ideas, and learning about their work.
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| Meals on the cruise |
Before this cruise, most of my research experience had been focused on laboratory experiments, sample preparation, and data analysis. Although I frequently worked with seawater samples and oceanographic datasets, I had never personally experienced the process of collecting those samples from the ocean.
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| Suruga Bay and Mt.Fuji |
This cruise helped me realize how much work goes into obtaining even a single bottle of seawater. Behind every sample and dataset are careful planning, technical expertise, teamwork, and many hours of hard work at sea.
Despite the demanding schedule and physical exhaustion, I genuinely enjoyed this experience. I learned not only practical sampling techniques but also the importance of communication, flexibility, and teamwork in field research.
Looking back, these ten days aboard *Hakuho Maru* were both challenging and rewarding. My first research cruise has given me a new perspective on oceanographic research, and I hope to have more opportunities to participate in fieldwork in the future.
