Image courtesy of Wikipedia / Photo by Diego Delso
A school of black sea bream swimming in Tokyo’s Kanda River. Some of them are over 40 centimeters long and have been caught. But why are black sea bream in the river in the first place?
■A large one over 40 centimeters caught during the interview In the Kanda River, which flows through Taito Ward in Tokyo, the shadows of black fish can be seen swimming one after another. We asked Mr. Kudo, who has been studying fish in Tokyo Bay for over 40 years, about the identity of these mysterious fish… Takahiro Kudo, an expert on fish in Tokyo Bay: “They are definitely black sea bream.” On the 28th, the school of black sea bream was spotted near Yanagibashi Bridge over the Kanda River. A man who has been running a shop along the river for over 60 years could not hide his surprise. Osamu Akimoto, owner of Yanagibashi Komatsuya: “I have never seen a sight like this in my life. I noticed it two or three days ago.”
According to experts, black sea bream are originally fish that inhabit the area around Tokyo Bay. Takahiro Kudo, an expert on fish in Tokyo Bay, says, “They are not fish that normally migrate in schools. I have never seen them swimming in such large formations before.” Furthermore, the anomaly is not limited to the Kanda River. Angler: “(Q. What are you targeting?) Black sea bream” Anglers targeting black sea bream can be seen in the Sumida River, the main stream of the Kanda River. According to the Tokyo Metropolitan Government, there is no problem with fishing as long as it does not bother others. Then, a fish with large pectoral fins and a flattened shape when viewed from the side took the hook. Based on these characteristics, it was confirmed to be a black sea bream, about 40 centimeters long. After taking a commemorative photo, the angler releases the black sea bream back into the river.
■Why are there schools of black sea bream in Tokyo’s rivers? Why are black sea bream, which are normally found in the sea, gathering in Tokyo’s rivers? According to experts, there are two reasons. The first is… Takahiro Kudo, an expert on fish in Tokyo Bay, says, “The environmental changes in Tokyo Bay are a very significant phenomenon. Climate warming, plus the large meander of the Kuroshio Current. Salinity is rising and water clarity is increasing.” The first reason is that the environment of Tokyo Bay has changed. Due to global warming and the effects of the Kuroshio Current’s large meander that has continued for many years, shellfish and other food sources for black sea bream have drastically decreased. Therefore… Takahiro Kudo, an expert on fish in Tokyo Bay, says, “(Q. Are they crossing to the rivers in search of food?) Yes. Aiming for new territory.”
The second reason is the toughness of the black sea bream. Takahiro Kudo, an expert on fish in Tokyo Bay, says, “When environmental changes occur in Tokyo Bay, naturally, creatures that have lived in Tokyo Bay for a long time can no longer live there. Global warming in particular makes it difficult for seaweed to grow, and the lack of oxygen directly kills the creatures that live there. Black sea bream themselves are tough animals with very strong adaptability.” These changes may be leading to the unusually large schools of fish seen in rivers within Tokyo. On the other hand, the taste is a concern.
While black sea bream (kurodai) is not very common in the Kanto region, it is known as “chinu” in western Japan and is enjoyed as sashimi or simmered fish. So, is it safe to eat black sea bream caught in Tokyo’s rivers? Takahiro Kudo, an expert on fish in Tokyo Bay, says, “There are concerns about whether it contains harmful substances, and I think it’s necessary to thoroughly check for chemical substances.” If you’re particularly concerned about the taste of the black sea bream you’ve caught, he recommends taking it to a fish market or similar establishment to have a professional assess it. [TV Asahi NEWS] https://news.tv-asahi.co.jp
