https://www.reuters.com/business/environment/fatty-katsuo-fish-may-foreshadow-climate-change-threat-japans-sushi-2022-07-12/
Fatty 'katsuo' fish may foreshadow climate change, threat to Japan's sushi.
NAKATOSA,
Japan, July 12 (Reuters) - For half a century, Takeo Nakajo has been
catching katsuo, or skipjack tuna - indispensable in Japanese cuisine
whether eaten raw, dried or used as a base for the broth.
But
he and other fishermen in Kure, in Kochi prefecture in southwest Japan,
have seen something worrying in the past two years - an unprecedented
number of unusually fatty katsuo.
While
heavier katsuo means more money, locals and experts say it indicates
climate change and a risk for katsuo numbers already under threat due to
growing demand and overfishing.
Register now for FREE unlimited access to Reuters.com Photo essay:
NAKATOSA,
Japan, July 12 (Reuters) - For half a century, Takeo Nakajo has been
catching katsuo, or skipjack tuna - indispensable in Japanese cuisine
whether eaten raw, dried or used as a base for the broth.
But
he and other fishermen in Kure, in Kochi prefecture in southwest Japan,
have seen something worrying in the past two years - an unprecedented
number of unusually fatty katsuo.
While
heavier katsuo means more money, locals and experts say it indicates
climate change and a risk for katsuo numbers already under threat due to
growing demand and overfishing.
"The
fatty katsuo must have something to do with the water temperature,"
said the 70-year-old Nakajo. "I have a sense of urgency thinking what if
katsuo doesn't come to the bay some day." (Photo essay: https://reut.rs/3AFtYSQ)
Noriaki
Ito, the head chef at a century-old restaurant Tsukasa in Kochi City,
said he too had "never seen such fatty katsuo during this season of the
year".
This
is worrying as changes in the sea and climate have already wiped out
some other fish "including a shellfish called chambara-gai that used to
be Kochi's speciality", Ito added.
Register now for FREE unlimited access to Reuters.com Photo essay:
NAKATOSA,
Japan, July 12 (Reuters) - For half a century, Takeo Nakajo has been
catching katsuo, or skipjack tuna - indispensable in Japanese cuisine
whether eaten raw, dried or used as a base for the broth.
But
he and other fishermen in Kure, in Kochi prefecture in southwest Japan,
have seen something worrying in the past two years - an unprecedented
number of unusually fatty katsuo.
While
heavier katsuo means more money, locals and experts say it indicates
climate change and a risk for katsuo numbers already under threat due to
growing demand and overfishing.
"The
fatty katsuo must have something to do with the water temperature,"
said the 70-year-old Nakajo. "I have a sense of urgency thinking what if
katsuo doesn't come to the bay some day." (Photo essay: https://reut.rs/3AFtYSQ)
Noriaki
Ito, the head chef at a century-old restaurant Tsukasa in Kochi City,
said he too had "never seen such fatty katsuo during this season of the
year".
This
is worrying as changes in the sea and climate have already wiped out
some other fish "including a shellfish called chambara-gai that used to
be Kochi's speciality", Ito added.
Originally
from tropical waters, some Pacific katsuo migrate northward on a warm
ocean current every spring, making Kochi's arc-shaped bay a fertile
fishing ground.
The
average surface temperature of the bay in winter has risen by 2 degrees
Celsius in the four decades to 2015, local fisheries lab data shows,
and the fatter katsuo may be due to ample prey in the warmer sea.
But
longer term, this warming may prevent mineral-rich water from rising to
the surface, resulting in a drop in plankton and smaller fish to feed
on, leading to fewer katsuo, said Hiroyuki Ukeda, an agroscientist and
vice president of Kochi University.
Register now for FREE unlimited access to Reuters.com
NAKATOSA,
Japan, July 12 (Reuters) - For half a century, Takeo Nakajo has been
catching katsuo, or skipjack tuna - indispensable in Japanese cuisine
whether eaten raw, dried or used as a base for the broth.
But
he and other fishermen in Kure, in Kochi prefecture in southwest Japan,
have seen something worrying in the past two years - an unprecedented
number of unusually fatty katsuo.
While
heavier katsuo means more money, locals and experts say it indicates
climate change and a risk for katsuo numbers already under threat due to
growing demand and overfishing.
"The
fatty katsuo must have something to do with the water temperature,"
said the 70-year-old Nakajo. "I have a sense of urgency thinking what if
katsuo doesn't come to the bay some day." (Photo essay: https://reut.rs/3AFtYSQ)
Noriaki
Ito, the head chef at a century-old restaurant Tsukasa in Kochi City,
said he too had "never seen such fatty katsuo during this season of the
year".
This
is worrying as changes in the sea and climate have already wiped out
some other fish "including a shellfish called chambara-gai that used to
be Kochi's speciality", Ito added.
Originally
from tropical waters, some Pacific katsuo migrate northward on a warm
ocean current every spring, making Kochi's arc-shaped bay a fertile
fishing ground.
The
average surface temperature of the bay in winter has risen by 2 degrees
Celsius in the four decades to 2015, local fisheries lab data shows,
and the fatter katsuo may be due to ample prey in the warmer sea.
But
longer term, this warming may prevent mineral-rich water from rising to
the surface, resulting in a drop in plankton and smaller fish to feed
on, leading to fewer katsuo, said Hiroyuki Ukeda, an agroscientist and
vice president of Kochi University.
This
comes as Japan's ageing population is threatening the sustainability of
local fishing and related businesses such as the production of dried
and fermented katsuo, and wasabi horseradish - an eye-watering condiment
tucked under fish in a piece of sushi. read more
In
Kure, a district in Nakatosa town, many fishermen have gone out of
business in the past three decades, said Takahiro Tanaka, a
fourth-generation owner of a fishmonger who calls himself a "katsuo
sommelier".
"We
can distinguish different tastes of katsuo, just like ordinary French
farmers may savour subtleties of wine ... this place might be one of
Japan's last communities where katsuo is part of the daily culture," he
added.
"But without fishers, this won't last," Tanaka said.
Fisherman
Nakajo also rued the ageing community and fewer successors. "I asked my
grandson if he would take over, but he's now studying to work at a
government office," Nakajo said.
SUSHI CULTURE AT RISK
Overfishing
has already hit catch numbers and dealt a blow to the fishermen in
Kochi who have stuck to traditional single pole fishing methods versus
large-scale seine fishing across the western Pacific.
Government data shows catch numbers in Kochi are only at a quarter of their 1980s peak.
"We have observed a catastrophic decline in landings over the last 10 years or so," said Ukeda.
"A growing number of people fear we may no longer be able to eat katsuo in the near future if things continue like this."
Production
of katsuobushi, dried and fermented katsuo, often used as a shaved
condiment over traditional Japanese dishes or as a broth base, is
already suffering.
The
number of katsuobushi manufacturers in Kochi has plunged from dozens
some forty years ago to only a few, said Taichi Takeuchi, who runs one
in the town of Usa.
"I'm really unsure if we can continue this," said Takeuchi.
Wasabi,
the tangy horseradish that is an essential for Japanese food,
especially sashimi and sushi, is facing similar production challenges. read more
Typhoons
and rising temperatures have hurt production in Okutama, a mountainous
area to the west of Tokyo, said Masahiro Hoshina, 72, head of the local
wasabi growers' association.
"I am extremely worried about the future of our farming," Hoshina said.
The
number of farmers in the area is down 75% from the 1950s due to
depopulation, and unless something changes, some worry sushi itself
could be endangered.
"The
combination of raw fish and spice, as in katsuo and wasabi, is an art,
and we must maintain both," said Ukeda. "I never want to think about a
future" without them, he added.
(The story corrects name in paragraph 8, Hiroyuki Ukeda not Hideyuki Ukeda)
