There are a large number of dead fish floating in the Poche fishing port of Shima City, Mie Prefecture, Japan (**Source: Zhongxin**screenshot).
Cover News Reporter Tan Yuqing.
According to Japanese media reports, recently, a large number of dead fish floated in the Poche fishing port in Shima City, Mie Prefecture, Japan. Some of the dead fish in the fishing port have rotted and begun to emit a foul smell, and fishery workers are dealing with it, as of December 14, local time, it has been 85 tons.
Judging from the footage of the report, there are a large number of dead fish, and part of the beach and water surface are covered and turned silvery white. The Mie Prefecture Fisheries Research Institute said on the 14th that after sampling investigation, the cause of the fish's death may be related to lack of oxygen.
This is not the first time this month that Japan has seen a "dead fish wave". NHK TV reported on December 7 local time that a large number of dead sardines and other fish appeared on a beach in Hakodate City, Hokkaido. According to the report, the beach about 1 kilometer long is littered with sardines and other fish carcasses.
The fish are mainly sardines, the local ** said in a statement. The statement also urged local residents not to take the dead fish home for consumption. At present, the relevant personnel are conducting a detailed investigation and discussing the treatment plan.
Researchers at the Hakodate City Fisheries Research Institute said the event occurred at the same time as the season when sardines migrated south from Hokkaido. One possible reason is that the group of fish was chased and preyed upon by a large fish and was washed up by the waves after exhaustion;Another possible reason is that schools of fish were washed ashore in the middle of their migration in the same way as they moved by icy currents, but the exact details are uncertain.
Some members of the public have expressed concern about the recent "dead fish tide" off the coast of Japan, which may indicate that the marine ecosystem is changing. On December 22, the cover news reporter spoke to relevant fishery experts about this phenomenon.
The expert said that the "tide of dead fish" on the beach is not so uncommon, "Occasionally, this happens, because of the influence of extreme weather, such as too cold or too hot, etc., this sudden change in the environment, there will be a large number of fish deaths." ”
Experts believe that the recent mass death of sardines in Hokkaido may be related to temperature or predators, "Now that the weather is getting colder, sardines are starting to migrate to the south, and the water is a little warmer in the south." It may have died in such a large number as it migrated south. I saw an explanation that it might have been pursued by dolphins or whales, and that it might have died in large numbers as soon as it fled into a harbor. ”
The expert also mentioned that it is often the fish with large resources and clusters that there are noticeable mass deaths, "If the fish themselves are very small, one or two may die and no one will pay attention." It is because the fish itself is now very abundant, that is, it is very abundant, so the occurrence of death may attract everyone's attention. ”
According to the data, sardines are group migratory fish that usually go to depths of 25-100 meters during the day and rise to depths of 5-10 meters at night. In early March, schools of sardines depart in batches from deeper areas and swim to waters close to shore for bait for a three-month breeding season. That is, they live in coastal waters in spring and summer, and migrate to deep sea areas with high water temperature in autumn and winter when the water temperature is low.
In addition to escaping with the fast swimming speed that most fish do, sardines also use group behavior to evade predators. For example, when encountering dolphins that prey on sardines, sardines will gather in large groups to fight off the dolphinsIn the absence of external threats or obstacles, schools of fish often congregate into near-spherical forms in order to coordinate evasion.