＜prologue＞
I started a blog called “The Baby Boomer Generation’s Miscellaneous Blog”（Dankai-sedai no garakutatyou:団塊世代の我楽多（がらくた）帳） in July 2018, about a year before I fully retired. More than six years have passed since then, and the number of articles has increased considerably.
So, in order to make them accessible to people who don’t understand Japanese, I decided to translate my past articles into English and publish them.
It may sound a bit exaggerated, but I would like to make this my life’s work.
It should be noted that haiku and waka （Japanese short fixed form poems） are quite difficult to translate into English, so some parts are written in Japanese.
If you are interested in haiku or waka and would like to know more, please read introductory or specialized books on haiku or waka written in English.
I also write many articles about the Japanese language. I would be happy if these inspire more people to want to learn Japanese.
my blog’s URL:団塊世代の我楽多（がらくた）帳 | 団塊世代が雑学や面白い話を発信しています
my X’s URL:団塊世代の我楽多帳（@historia49）さん / X
On September 11, 2019, the high-profile Mr. Shinjiro Koizumi was appointed Minister of the Environment. I hope that Minister Koizumi will stop and reconsider whether the current way of proceeding is correct with regard to the “global warming issue” and the “marine plastic waste issue,” which are often the focus of attention with regard to “environmental issues.
What I think is most problematic at the moment is the “problem of the breeding of specified alien species,” which are targeted for extermination, and the “problem of damage to crops by wild birds and animals” and the “problem of crows devouring raw garbage,” which are targeted for protection. These three are more pressing issues for Japan. I have great expectations that the new minister will be able to come up with effective countermeasures.
1. research on eradication of bluegill by sterilization
On July 31, 2019, the Mainichi Shimbun reported, “Genetic Manipulation to Eradicate Invasive Alien Fish: Sterilizing Bluegill Aimed at Practical Use in Lake Biwa.
This is a demonstration experiment to sterilize and eradicate bluegill, an invasive alien fish that adversely affects the ecosystem, by using “genome editing” technology to efficiently modify genes. A research team from the National Fisheries Research and Education Organization and Mie University began research on this “gene suppression method” in 2014.
They have already spent 89 million yen in the fiscal years 2014-2018. Within a few years, they are planning to release the fish into ponds in the Kinki region, collect experimental data, and implement the project in Lake Biwa.
2. History of bringing in bluegill
Currently, “black bass” and “bluegill” are the two most common nuisance alien fish in Lake Biwa.
Of these, the bluegill was actually first brought back to Japan as a gift from the mayor of Chicago when the emperor visited the U.S. during his time as crown prince.
Wikipedia says the following
The first 15 fish were introduced to Japan in 1960, when then Crown Prince Akihito of Japan brought 15 native to the Mississippi River system caught in Guttenberg, Iowa, back to Japan as a donation from the mayor of Chicago during a visit to Japan.
Fifteen of these fish were bred by the Freshwater Research Institute of the Freshwater District of the Fisheries Agency as food research subjects and then released into Lake Ippeki in Ito City, Shizuoka Prefecture, in 1966. This was proven by the results of mitochondrial DNA analysis published by the Faculty of Bioresources at Mie University in 2009, which showed that the nucleotide sequences of all 1,398 specimens collected at 56 sites in all prefectures matched perfectly with those collected in Guttenberg among samples collected at 13 sites in the United States.
The former Emperor had no ill intentions and was just thinking, “Maybe they could be edible?” However, the result has now become a situation where we are struggling to eradicate them. If they had been kept in an aquarium in the Imperial Palace, or at best in the gardens of the Imperial Palace, it would have become clear just how ferocious and terrifying a fish they are, devouring all the native fish.
However, the Fisheries Agency research institute that received the donation from the Crown Prince bears a greater responsibility. At the time, I do not know whether they lacked knowledge about bluegills and thought they could coexist peacefully with Japan’s native fish, or whether the people at the Fisheries Agency research institute lacked knowledge about the destruction of ecosystems, but they made an “irreparable blunder.”
Also according to Wikipedia, in 2007 the former Emperor made the following statement.
Regarding the bluegill, which is now causing serious problems as an invasive species, the Emperor stated at the 27th National Convention for the Conservation of the Sea in 2007, after his accession to the throne, “The bluegill was brought back from the United States by myself nearly 50 years ago and donated to a Fisheries Agency laboratory, which began to cultivate it as a food fish.
However, I regret that it has now become a villain that is destroying native fish species,” he said.
Bluegills pose a serious threat to the ecosystems of Japanese ponds and lakes in terms of their reproductive and vitality potential, predation, competition for food, and predation on the eggs and fry of native fish species. Moreover, they are neither suitable for eating nor for fishing.
3. “Gene suppression” approach to extermination of non-native fish is questionable
I am not an expert and do not have any scientific evidence, but I have my doubts about this approach.
(1) Simply releasing sterile bluegill into ponds on an experimental basis will have a “negative impact on the ecosystem”.
(2) Releasing additional sterilized bluegills into bluegills that are reproducing out of control, as is currently the case in Lake Biwa, is like “pouring oil on the fire”!
(3) With far more bluegills than sterile bluegills, “How many decades do you think it will take to eradicate them?” question
According to an estimate based on data from lakes in the U.S., “If less than 10% of the original population is released every year and combined with capture, there is a possibility of eradication in a few decades in Lake Biwa and other lakes. However, the capture will probably include sterile bluegill, and in the first place, just releasing 10% more bluegill than now would further reduce the number of native species”.
Currently, there are about 1,000 tons of bluegill in Lake Biwa, and releasing an additional 100 tons of bluegill every year seems insane…
It seems to me that the Fisheries Research Institute of 1960 is repeating the same mistake of releasing bluegill.
4. learn from the example of the failed attempt to exterminate hubs by introducing mongooses
I wrote an article on “Hubs and Mongooses” before. In the past, when the people of Okinawa were suffering from damage caused by hubs, a famous zoologist from the University of Tokyo gave them advice that they could eliminate the hubs by introducing mongooses, which they did, and now they are struggling to exterminate the mongooses because of their overabundance.
We hope that they will not “follow the rut of the previous vehicle”.
After all, although it may be analogous, I think it is best to have the fishermen focus their efforts on the thorough capture and extermination of bluegill, even if they have to pay the fishermen 100 million yen, which is equivalent to the research expenses mentioned above. I think there is room for research on whether captured bluegill should be used as-is for food, feed, or disposal.
