Hakuho-Maru, in the Port of Yokosuka
白鳳丸での調査について，M2のLiさんが報告してくれました！
From December 8th to December 25th in 2020, I joined a survey conducted by Hokkaido University and had a chance to board on a research vessel named Hakuho-Maru. Although I have joined the onboard survey several times, this is my first time boarded on a research vessel. The objective of this time’s voyage is to illuminate the marine ecosystem off the coastal water around Shiretoko before the sea ice occurrence. The research team was composed of different majors but all related to oceanography, including physics, chemistry, plankton, and marine mammals researchers.
I have experienced the ocean in September and October before, but never seen the ocean in December. For us, what kind of marine mammals could be encountered at the sea in December was the biggest curiousness. Our voyage started from the Port of Yokosuka, which means we also have the opportunity to meet some marine animals on the Pacific side around Honshu island. The voyage started upon in a beautiful sunny afternoon and northward sailing to Hokkaido.
Marine mammals’ sighting survey is conducted on the upper bridge, the view is so broad that you could look for animals by binoculars. But meanwhile, the wind at sea is so strong that it is necessary to make a barrier covering observers during the survey. If you zoom up, on the first photo you could vaguely see the banner, which helps us resist the chilly wind (thanks to the staff who helped us with that!). The first afternoon ended in the vessel tour, security education, and many other activities. To be honest, Hakuho-Maru is so huge that even though I joined the vessel tour I still got lost many times in the beginning.
Sighting survey started 1 hour after the sunrise and ended 1 hour before the sunset. Strong wind at December’s sea left me a deep impression on the first day of the survey, wind got stronger in the first two-hour. Bad weather with bumpiness forced us to move everything down into the bridge. However, wind speed slowed down before lunchtime and we were able to conduct the survey on the upper bridge again. The first marine mammal we found was the Pacific white-sided dolphins, although they are common to be seen at the sea around Japan it is exciting to see them after experiencing such terrible weather. Besides, we also saw Dall’s porpoises and northern fur seals, the first day of our survey started in the strong wind but end with some gains.
Pacific white-sided dolphins, photo took on the first day of our survey
The second day when we woke up our vessel had already passed through the Tsugaru Strait into the Sea of Japan and I saw a familiar island, Matsumae-Kojima. Also, from the snow-covered mountains as well as the colder temperature it was obvious that we were in the coastal water around Hokkaido. In the water around southern Hokkaido, we found northern fur seals, Pacific white-sided dolphins, Dall’s porpoises, and saw a group of cetaceans that looked like Baird’s beaked whales.
Matsumae-Kojima in a December morning
From Dec 11th to 13th, we were in the Sea of Okhotsk, compared to the coastal water around southern Hokkaido we didn’t find so many marine animals but only a group of cetaceans that looked like Baird’s beaked whales. Besides, as this time’s survey was a joint investigation that after we sailing into the Sea of Okhotsk there were some stations that needed to conduct other kinds of surveys in order to study the chemical and physical characteristics of the Okhotsk Sea. To avoid duplicate counting animals, sighting survey stopped at stations and only conducted between stations. Compared to marine mammals there were many seabirds in December’s Sea of Okhotsk, weather was getting colder and colder in the north sometimes snowed at the sea. Besides numerous seabirds, we also met a beautiful sunset after setting the Mooring System.
Beautiful sunset in the Sea of Okhotsk
“Nice timing! We just arrived at the Cape Shiretoko.” The officer told me before we prepared to go to the upper bridge. We entered the Nemuro Strait on Dec. 14th morning and stayed there till Dec.20th. There, the weather became much colder, chilly winds and heavy snow occurred very often and we were forced to wear special clothes to protect us from the extreme cold weather. I remembered that one day the wind was so strong and the big wave was high enough reached to the upper bridge and we were almost blown away by the strong wind. While we remaining in the Nemuro Strait we were expecting to find if there any marine mammals there, however, only found cetaceans that looked like Baird’s beaked whales. Although we didn’t see many marine mammals, there were indeed many seabirds and we saw the Steller’s Sea eagle there! It was hovering above the vessel looked like targeting something, it’s a pity that we didn’t take a photo.
Part of Shiretoko Peninsular, Rausu-cho, very beautiful in the winter but so cold
Have you ever tried a roller coaster or other bumpy facilities at the amusement park? Well, if you have ever tried those rides you might know the feeling when we pulled out the vessel from Nemuro Strait into the Sea of Okhotsk. I was forced to roll on my bed by the coming after waves, also I could hear some goods rolling on my desk. Fortunately, after that sea condition was not so terrible.
In the coastal water around Shiretoko Peninsular we didn’t see many marine mammals but just found some small-sized dolphins. However, after we left the Sea of Okhotsk southward sailing to the Honshu island, we saw northern fur seals around the Hiyama subprefecture. The next day after we passed the Tsugaru strait, we saw large groups of Pacific white-sided dolphins nearby Sendai Bay. Although we met northern fur seals and Pacific white-sided dolphins at the beginning of the voyage, the encounter frequency was incomparable on the way back. I was impressed by the spatial and temporal difference in marine mammals’ distribution, and that feeling was apparent as we almost use the same route during the voyage.
A group of Pacific white-sided dolphins
I would choose two words to describe this time’s survey, exhausting but amazing. It is so amazing when I see marine mammals’ distribution are changing spatially and temporally with my own eyes. The sea in December gave me a lot of surprises and left me a lot of good memories. Except for the sea, people, food, and desserts (especially the peppermint chocolate flavour ice cream) on the Hakuho-Maru also are unforgettable. I’m looking forward to the next time voyage!
Dinner and a piece of chocolate cake on the Christmas Eve
