My Hobbies
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During the
summer I often take my daughters to a nearby river. I was born and
raised around there, so I have been familiar with the river, but I have
noticed in recent years that foreign species have been rampant there.
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My hobbies include keeping fish and shrimps. Especially,
I love medaka, Japanese killifish. I often take my children to a nearby
river in the summer. We play in the water, catch fish and shrimps, and
enjoy barbecue. There are many fish there, but I have noticed that
there are very few medaka in recent years. They say that the fish is on
the verge of extinction. Medaka is a small, low-key fish. It was a very
common fish when I was a child. It was everywhere, and even children
could easily catch and raise it. What is significant about this is that
something that used to be
such a common living creature decades ago is now listed as an
endangered species. It is sold at around 100 yen at pet shops now. It
is nearly the same as the price of a guppy. Recently, I often see
guppies in the nearby river. Someone must have released them. This is
outrageous, because a single foreign species can affect the entire
ecosystem. Guppies were originally tropical fish, but
probably because of the recent climate change they have survived winter
in Japan. Moreover, medaka lay eggs, which are often eaten by other
fish, including their parents, whereas guppies keep eggs inside their
bellies until they hatch, so they are less susceptible to predators. Therefore, guppies have displaced indigenous
fish in some rivers. In addition to the invasion of the foreign fish,
the use of pesticides and bank protection works are seen as the reasons
for the sudden decrease of medaka. The declining number of medaka have not drawn
much public attention as something like the Iriomote cat, but I think,
given the sudden decrease, this issue is more serious.
I dealt with a real haunted house last summer.
It was haunted by honeybees. There were myriads of honeybees, both dead
and alive. I spent a lot of time and
energy, cleaning up the house.
Since then, I have sometimes had a nightmare of being attacked
by a cluster of bees. I work hard like a bee during the daytime, and I
am run after by bees at night. When I was watching a TV program for
kids with my
daughters the other day, I leaned about an amazing self-defense
function of honeybees. A hornet, which is honeybee’s archenemy,
captures
and eats honeybees. Hornets are much bigger than honeybees and
ferocious. No matter how we look at it, honeybees have no chance of
winning, but when a hornet comes too close to a honeybees’ hive,
honeybees go on the counterattack. Hundreds of honeybees surround the
hornet and keep it inside the ball of honeybees for about 20 minutes.
Eventually, the hornet is killed. The honeybees do not sting it, but
smother it to death. They continue to move their bodies briskly and
raise
the temperature of the inside of the ball. Honeybees survive the high
temperature that kills hornets.
Honey is believed to be good for the health, but books on child-rearing warn parents not to give their children honey. They say that honey can cause infants to get food poisoning as it sometimes contains the germs, which are fatal to babies under a year old. I am cautious about giving my daughters honey, but I love it, so when a friend of mine went on a honeymoon to New Zealand, I asked him to buy honey as a souvenir. Honey is one of the most popular souvenirs in New Zealand. He brought me back a small bottle of propolis and a box of candy containing Manuka Honey. Propolis is a product of honeybees, too. It is pine-tar-like, thick liquid. Actually, it smells like pine tar. Some people say it has various, mysterious effects. They believe that it is a panacea, which cures every disease from a cold to a cancer. I tried it, but the thick liquid stained my teeth, so I stopped using it. Manuka Honey seems to be a mysterious honey, too. It is referred to as a natural antibiotic. As I liked the candy’s taste, I bought two bottles of Manuka Honey later. They cost more than 5,000 yen. Manuka Honey was much darker than common honey. Its taste was rich and thick though its mysterious effects did not work for me.
Recently, a huge number of honeybees have disappeared suddenly and mysteriously. This has become a very serious problem across the world. As the guppies I saw in the nearby river tell us about the recent climate change, honeybees may warn us of the danger that the ecosystem is facing now because they are much more susceptible to subtle changes in the environment than humans.
Honey is believed to be good for the health, but books on child-rearing warn parents not to give their children honey. They say that honey can cause infants to get food poisoning as it sometimes contains the germs, which are fatal to babies under a year old. I am cautious about giving my daughters honey, but I love it, so when a friend of mine went on a honeymoon to New Zealand, I asked him to buy honey as a souvenir. Honey is one of the most popular souvenirs in New Zealand. He brought me back a small bottle of propolis and a box of candy containing Manuka Honey. Propolis is a product of honeybees, too. It is pine-tar-like, thick liquid. Actually, it smells like pine tar. Some people say it has various, mysterious effects. They believe that it is a panacea, which cures every disease from a cold to a cancer. I tried it, but the thick liquid stained my teeth, so I stopped using it. Manuka Honey seems to be a mysterious honey, too. It is referred to as a natural antibiotic. As I liked the candy’s taste, I bought two bottles of Manuka Honey later. They cost more than 5,000 yen. Manuka Honey was much darker than common honey. Its taste was rich and thick though its mysterious effects did not work for me.
Recently, a huge number of honeybees have disappeared suddenly and mysteriously. This has become a very serious problem across the world. As the guppies I saw in the nearby river tell us about the recent climate change, honeybees may warn us of the danger that the ecosystem is facing now because they are much more susceptible to subtle changes in the environment than humans.
Currently I am really into making a
“biotope.”
In recent years, many parks and schools have included a pond
called “biotope.” The biotope is a self-sufficient biological
community, and an ecosystem is artificially reproduced there. It is
abundant in aquatic lives, but no one feeds the creatures. In the
biotope, plankton feed aquatic animals and small creatures are eaten by
carnivores and their dead bodies and feces are eaten by shrimps or
lochs and fertilize weeds and weeds provide oxygen. This cycle is
maintained there. There are some biotopes near my house, too. I
sometimes take my daughters there on weekends. We enjoy catching
aquatic creatures. Until the recent renovation project, there was a
pond in the Imadegawa campus. There were some carps there, but I never
saw someone feed them. The water was dark green. This meant that
there was a lot of phytoplankton. It must have provided the carps with
the source of food. That is, the pond was a “biotope.” I often observed
this pond for a while as I was interested in aquatic lives. I have
three aquariums inside the house and a huge plastic container outside.
I feed fish in the aquariums, but I do not feed the creatures outside
on purpose as I have made the container a “biotope.” I have been
keeping
weeds, fish, and shrimps in it. As I do not feed them, some of them die
gradually, especially during the winter, when the number of
phytoplankton goes down. A small number of fish and shrimps survive the
severe season. There is a very delicate balance of a food web there.
This “biotope” has served as a good educational material about ecology
for my daughters.