SEA LIFE IN JAPAN: DEEP SEA, GIANT AND BIOLUMINESCENT CREATURES

JAPAN NO. 1 IN MARINE LIFE BIODIVERSITY

oarfish

The marine life around Japan is incredibly rich and diverse. One of the main reasons for this is the convergence of hot and cold currents in waters around Japan’s islands, the rich variety of coastal environments; changing weather; and varied underseas topography. Deep trenches lie just offshore on the Pacific Ocean side — the Kuril and Japan Trenches in north and the Ryukyu and Marianas Trenches in the south. Converging plates produces undersea mountains.

The Census of Marine Life, released in 2010, counted 33,629 species of sea creatures, the widest diversity of species in 25 oceanic regions, in waters around Japan. Even though waters around Japan count for only 1 percent of the world’s ocean, 15 percent of all sea creatures live there, including 8,658 species of mollusks and 6,393 species of arthropods. The high diversity is attributed to varied environments that exist in Japan, where you get sea ice off Hokkaido and coral reefs off Okinawa.

A 2010-2011 White Paper on Fisheries of Japan listed the following reasons for richness of Japanese waters: 1) The Oyashio Current (rich in nutrient salt and encourages plankton growth) and the Kuroshio Current (although poor in nutrient salt, brings fish from southern sea areas to waters around Japan) intersect and form an “Avenue of Fish.“ 2) Continental shelves have developed along the coasts of Hokkaidō, the Tōhoku region, and the San’in region at a depth of approximately 200 m, which is suitable for the habitats of bottom fish. Meanwhile, the Sea of Japan has the Yamato Bank and the Musashi Bank, which are terrace-shaped shallow sea areas. 3) The East China Sea, and many of the inner bays (such as the Funka Bay, Ise Bay, Ariake Sea, and Yatsushiro Sea) found along Japanese coastlines provide grounds for abundant fishery resources due to the rich nutrient salt carried in from land areas.

Giant Sunfish Caught off Hokkaido

sunfish (mola mola)

In August 2014, an enormous sunfish caught off Hakodate, Hokkaido The Yomiuri Shimbun reported: The giant sunfish was more than 3½ meters long and weighed more than one ton .Fishermen belonging to the Minami-kayabe fisheries cooperative found the sunfish as they lifted a fixed net on Thursday morning. Based on its size, it is believed to be a type of sunfish called ushi manbo. [Source: Yomiuri Shimbun, August 16, 2014]

“Yasunori Sakurai, a specially appointed professor at Hokkaido University, and graduate student Hajime Matsui, 24, were on the boat when the sunfish was caught. “I’ve conducted marine research for more than 30 years, but this was the first time for me to see a sunfish as big as 3½ meters long,” said Sakurai, 63, who specializes in marine ecology.

Sunfish (Mola mola) can be seen seasonally at several different places in Japan and it is said the past sunfish actually played a role in the Shogunate’s taxation. 1) In Kantō they can be seen on special dives organised in Ito-Tateyama (Chiba Prefecture) and are also sometimes spotted in the Nanpō archipelago’s Izu and Ogasawara islands. 2) In Chūbu sunfish can be seen on various dive sites around the Izu peninsula (Shizuoka Prefecture) with access to deeper water, including Mikomoto island, and especially at the Nakagi, Osezaki (which is said to act as a cleaning station) and Futo dive sites between April and August. Molas are also spotted in early spring at Numazu and Ita areas, west of the Izu Peninsula. 3) In Shikoku sunfish are sometimes seen in the Uguru Island area or on more exposed Pacific coast sites of Okitsu and Muroto (Kōchi Prefecture). 4) In Kyūshū sunfish can be spotted at (Yamakawaoki Kamise in Kagoshima Prefecture and the Nichinan and Nobeoka areas in Miyazaki Prefectures and in the Satsunan islands (especially the Tokara islands) [Source: Blue Japan]

Deepest Ever Fish Filmed off Japan

In September 2008, a Japanese-British team found fish — hadal snailfish, a subspecies of scorpionfish — living at a depth of 7,700 meters in the seabed of the Japan Trench. It was the deepest-living fish ever found. The previous record depth for fish was 7,000 meters. Pictures of the fish were taken with a camera encased in reinforced glass and pressure-resistant steel attached do a line dropped from a ship off the coast of Ibaraki Prefecture.

In April 2023, scientists announced that they had filmed a fish swimming at the deepest depth ever recorded for a fish. The creature — a kind of snailfish of the genus Pseudoliparis — was filmed swimming at 8,336 meters (27,349 feet) by an autonomous "lander" dropped into the Izu-Ogasawara Trench, south of Japan beating the previous deepest fish observation — made at 8,178 meters further south in the Pacific in the Mariana Trench — by 158 meters. That fish that held that record was also a snailfish. [Source: Jonathan Amos - BBC Science Correspondent, April 2, 2023]

snailfish

The BBC reported: The lead scientist said the snailfish could be at, or very close to, the maximum depth any fish can survive. "If this record is broken, it would only be by minute increments, potentially by just a few meters," Prof Alan Jamieson, who lead the dive, told BBC News. The University of Western Australia deep sea scientist made a prediction 10 years ago that fish would likely be found as deep as 8,200 to 8,400 meters. Prof Jamieson has pioneered the use of instrumented deep-ocean landers.

The juvenile Pseudoliparis was filmed by a camera system attached to a weighted frame released from over the side of a ship, the DSSV Pressure Drop. Bait was added to the frame to attract sea life. Although a specimen was not caught to fully identify its species type, several fish were trapped slightly higher up in the water column in the nearby Japan Trench at a depth of 8,022m. These, again, were snailfish, Pseudoliparis belyaevi, and set a record for the deepest fish ever caught.

Prof Jamieson says the discovery of a fish deeper than those found in the Mariana Trench is probably due to the Izu-Ogasawara's slightly warmer waters. "We predicted the deepest fish would be there and we predicted it would be a snailfish," he said. "I get frustrated when people tell me we know nothing about the deep sea. We do. Things are changing really fast." Prof Jamieson is credited with discovering not just the deepest fish in our oceans but also the deepest octopus, jellyfish and squid.

Yokozuna Slickhead — the World’s Largest Deep-Water Bony Fish?

In 2016, marine biologist Yoshihiro Fujiwara was on a ship anchored off the coast of central Japan, when the crew landed a big, bizarre-looking fish. “Wow! We got a coelacanth!" refereing the legendary "living fossil" found in Africa and Indonesia. Lucy Craft of CBS News wrote: Fujiwara, whose specialty is "whale fall" communities — the rich ecosystems that spring up around and feed off whale carcasses — was equal parts thrilled and skeptical. “It was exciting," he told CBS News. "But this is a very well-studied bay."Indeed it is. Researchers have been building a taxonomy of specimens from Suruga, Japan's deepest bay, since the 19th century. The area is also one of the most heavily fished in the world. Surely, Fujiwara thought, someone had spotted this colossal creature before. [Source:Lucy Craft, CBS News, February 13, 2021]

“Amazingly, no one had. Fujiwara and his team from the Japan Agency for Marine-Earth Science and Technology (JAMSTEC) cross-checked reference books and consulted with colleagues around the world before concluding the spear-shaped, purple-hued creature from the deep was indeed a bonafide discovery. Three more specimens of the monster fish would be hooked that year, quickly preserved in formaldehyde or frozen for later perusal in the lab. Fujiwara and his team decided to name the new species "yokozuna slickhead," after the top rank in sumo wrestling. “I couldn't believe it," biologist Jan Yde Poulsen, a research associate with the Australian Museum and an authority on slickheads, told CBS News from his base in Denmark.

“Despite its hostile deep sea, pitch-black habitat, the slickhead wasn't just big, it was brawny. While other slickhead species gobble plankton and weak swimmers like jellyfish, DNA examination of the giant fish's stomach contents showed it hunted other fish, perhaps supplementing its diet by scavenging. Unlike the other 100-odd slickhead species known to the world, the yokozuna is a vigorous swimmer, possibly able to cover long distances, as evidenced by a few seconds of rare video captured with a baited camera at a depth of almost 8,500 feet. The slickhead's "broad gape" mouth houses multiple rows of teeth, conjuring up an extra-terrestrial monster. Fujiwara's team attempted to count the densely packed fangs and their strictly unofficial conclusion: "80 to 100" teeth in those jaws. The physical attributes, in addition to biochemical analysis, identified the yokozuna slickhead as an apex predator — the deep-sea version of a lion or killer whale. “We have so many dives worldwide," Fujiwara said. "But it's rare to see a top predator."

Researchers believe the yokozuna slickhead is the world’s largest bony fish living in water deeper than 1.25 miles. There are some very big deep water sharks which are cartilaginous fish not bony fish. By 2022, Six yokozuna slickheads had been caught, and then one about 2.5 meters (eight feet) was caught on camera. Bob McNally wrote in Sport Fishing: Scientists lured the oversize “slickhead” to a bait container on bottom 1.25 miles deep, 250 miles from Japan’s Suruga Bay, located southwest of Tokyo. Three cameras were positioned around the bait container to record what fish would do. One of the cameras got video of a giant yokozuna slickhead driving away other fish from the food. They calculated the size of the oversize slickhead at just over 8 feet in length. The estimate was based on the location and size of the bait container to the fish. “The one spotted this time was so huge that we repeatedly recalculated its size,” said Yoshihiro Fujiwara, a researcher for JAMSTEC. “There is a possibility that large unidentified deep-sea fish variants inhabit other waters as well,” he said.[Source: Bob McNally, Sport Fishong, August 4, 2022

Deep Sea Oarfish Pop Up in Japan

In 2009 and 2010 a number oarfish — strange ribbon-like creatures that normally live at depths between 200 meters and meters and aren’t seem near the surface — were seen in coastal waters in the Sea of Japan. They were most often spotted when strong winds blew from the sea. In the winter of 2014, rare oarfish that normally dwell deep in the ocean were caught in Toyama Bay on Japan’s northwestern coast. Nikkei reported: “Fishermen at Hatake Port, in the northwestern city of Oga, Akita Prefecture, on Jan. 28 spotted a massive, silver, snakelike fish near the surface. It took four men to hoist the roughly 3-meter monster out of the water. Staff members from the Oga Aquarium determined it was an oarfish — a species that normally lives at least 200 meters deep. “Oarfish have washed ashore and been caught in nets in Japan before, but this was still a highly unusual event. "I have never heard of a deep-water fish being pulled up alive like this," said Shinji Handa, 37, a staff member at the aquarium. The fish, still able to move the dorsal fin along its back, swam around in a tank for a while but died the following day.

“Down in Toyama Bay, also on Japan’s northwestern coast, two oarfish have been caught this winter — one in December and another on Feb. 7. The most recent one, a 1.5-meter specimen, has been cryogenically preserved at the Uozu Aquarium in Uozu, Toyama Prefecture. "We will examine its internal organs and what’s left of its food to try to find out more about oarfish ecology," an aquarium official said.

“Moving on down the coast to Shimane Prefecture, a deep-water species called Trachipterus ishikawae, or slender ribbonfish, is being caught in relative abundance. A fishery company in the Shimane city of Matsue has fixed nets placed at 40 meters below the surface, and every day it snares up to a dozen slender ribbonfish. They usually live at depths of 200 meters or more. “The fish can grow to two meters or more.

“While unusual fish and other sea-dwelling species do turn up from time to time, all these cases appear to add up to a trend. The big question is, why? Water temperature, perhaps? The Sea of Japan is 1-2 C colder than average. But an official of the Japan Sea National Fisheries Research Institute — an entity under the Fisheries Research Agency, an incorporated administrative agency — said water temperatures in fishing grounds near the coast have not changed from recent years. The official said the institute has yet to pinpoint reasons for the spate of strange catches. Explaining that deep-water fish are not strong swimmers, the official did suggest one possibility: "They may have been brought to the surface due to ocean currents generated by strong northerly winds."

Asian Sheephead Wrasse

The Asian sheepshead wrasse, known as kobudai in Japan, is one of the largest species of wrasse. Native to the western Pacific Ocean, it inhabits rocky reef areas and prefers temperate waters around the Korean Peninsula, China, Japan, and the Ogasawara Islands. It can reach one meter in length (3.3 feet) and weigh up to 14.7 kilograms (32 pounds). Wall Street Journal Wikipedia]

Male Asian sheephead wrasse ((Bodianus reticulatus or Semicossyphus reticulatus, also spelled sheepshead) have an odd-looking, bulbous head that. Ones found in waters off Sado Island in northern Japan were featured in the film “Oceans” and the BBC's Blue Planet 2. Adult females are able to change into males when they reach a critical body size; after the transition, the fish gains a bulbous forehead, and also starts exhibiting aggressive behavior. Post-transitioned males possess some left-over characteristics of females, including some ovariform gonads.

Asian sheephead wrasses have globiform and bulky body. Males are typically larger than females. They have a terminal mouth located at the very front of their head, pointing directly forward, with both upper and lower jaws being roughly the same length. Thus is consistent with the fact that this fish is usually present in the middle of the water column, and prefer to eat prey directly in front of them or beneath them. This fish has hard tooth-like structures present in the mouth, which are excellent for crushing crustaceans. Unlike many other wrasses, the Asian sheephead wrasse is not particularly colorful.

Asian sheephead wrasses can be easily be seen in Tohoku between July and September on Sado Island, Niigata Prefecture and in Ryutoanjima and Yotsushima in Yamagata Prefecture. It is also common in Chubu’s Otomi and Ishikawa area (Toyama Prefecture) and on various Shikoku sites on the Seto Inland Sea. [Source: Blue Japan bluejapan.org]

Sea Fireflies, 100,000 Glowing Jellyfish and the Nobel Prize

In the town of Tateyama about 50 miles south of Tokyo locals sometimes amuse tourists by dropping buckets of fish heads into the sea to bait "sea fireflies," bioluminescent crustaceans about the size of tomato seeds. When the fish heads are pulled up the attached crustaceans secrete trail of bioluminescent material said to look like shooting stars. During World War II these crustaceans were dried and crushed into a powder and carried by Japanese soldiers into the islands of the Pacific. At night the soldiers rubbed the powder on their hands to read maps. Until the outer of shell of the crustaceans are broken the biolement material can remain dormant for several years and be activated when the shells are broken. [Source: Paul Zahl, National Geographic July 1971]

Osamu Shimonmura and two American won the Noble in Chemistry in 2008 for discovering and developing a glowing jellyfish protein that has helped shed light on such key processes as the spread of cancer, the development of brain cells, the growth of bacteria, damage to cells by Alzheimer’s disease, and the development of insulin-producing cells in the pancreas. Shimomura worked at the Marine Biological Laboratory in Wood Hole, Massachusetts and the Boston University Medical School. He discovered the jellyfish protein, green fluorescent protein, or GFP, after extracting it from 100,000 jellyfish caught off the coast of the of the state of Washington, and isolated it. American Martin Chalfie and Roger Tsien explored how it works and applied it to medicine and other fields.

Shimomura needed a large number of jellyfish to extract and refine GFP. He collected them with the help of students, assistant researchers and his wife and kids. At certain times of the years the jellyfish that bore GFP — “Aequora victoreai” — were so thick local people said you could walk on water. For his research Shimomura needed about 3,000 jellyfish a day which were collected from a pier with long-handled nets and buckets. Many locals thought he intended to eat the jellyfish as sashimi. Over the past decade the number of jellyfish off the Washington coast have declined drastically and it is no longer easy to collect huge masses of them.

Cutting up the jellyfish was another problem. At first Simomura used scissors but later refashioned a meat slicer that he bought at a hardware store. He then dedicated himself to extracting and purifying GFP. In 1979 Shimomura unraveled the structure of GFP and discovered how it became luminous. At this juncture in his career he showed one scientist a fluid solution of GFP, saying “This has been purified from 100,000 jellyfish.”

GFP turns green when exposed to ultraviolet light and easily attaches to other protein whose movements can be tracked. . The Swedish Academy compared the discovery GFP to the development of the microscope and said the protein has been “a guiding star for biochemist, biologist, medical scientists and other researchers.” Shimomura told the Daily Yomiuri, “I was able to extract aequorin because I thought other researchers ideas were wrong...I became successful because I tried to extract only the illuminating substance.”

Sea Turtles and Japan

Green turtles, hawksbill turtles and loggerhead turtles nest in Japan. Green turtles (Chelonia mydas) nest in the Nansei and Nanpo islands. Hawksbill turtles (Eretmochelys imbricata) nest in the Ryukyu archipelago and loggerhead turtles (Caretta caretta) nest in Honshu, Shikoku, Kyushu, and the Nansei Islands. Sandy beaches in southwestern Japan, chiefly in the southern part of Kyushu, are the loggerheads sole egg-laying area in the North Pacific, After hatching baby turtles swim more than 10,000 kilometers riding ocean currents until they reach waters off of Mexico. There they he feed on shrimp and food and return to Japan to breed .

NGOs in Japan, Hawaii and Mexico are working together to track and protect loggerhead sea turtles, which are endangered in the North Pacific. Loggerhead turtles that are born on Yakushima Island and along the coast in Nambumachi, Wakayama Prefecture spend most of their life off the west coast of Mexico and California. When they reach sexual maturity between 14 and 20 years of age they swim 12,000 kilometers across the Pacific back to Japan to nest, and repeat the journey every other year.

The Osaka-based Sea Turtle Association is involved with outfitting a turtle, whose front flippers were bitten off in a shark attack, with prostheses and returning it to the sea. The first set of artificial flippers fell off after a few minutes, As of December 2009 the turtle was getting used its fifth pair but still had some ways to go before it was ready for the open sea.

Tortoise shell has traditionally been used to make brooches, hairpieces and other accessories. The yellow-colored plastron and back-and-brown-spotted carapace from shell from endangered hawksbill turtles is highly prized and has been dubbed the “jewel of the sea.” Tortoise shell craftsmen use a heated iron to bend and shape the shell and stick pieces together. If too much heat is applied the shell will char. If not enough is applies the pieces will come apart easily.

Shells from endangered hawksbill turtles are imported to Japan where they are carved in hair pieces traditionally worn by brides on their wedding day. Tortoise shell art is believed to have originated in China more than 2,000 year and was used in making the crown of Chinese Emperor Qin Shi Huangdi. In Japan , the industry has been centered in Nagasaki where hawksbill turtles were brought in by foreign traders. A craftsman at a tortoiseshell workshop that was established in 1709, told the Daily Yomiuri,, “People are attracted to tortoiseshell products because of their luster and their colors, which are peculiar to natural materials. Since each pattern is different, people can feel satisfaction by possessing something that is truly unique.”

Hunting sea turtles or collecting their eggs has been banned in Kagoshima Prefecture since 1988. Sea turtles have made a come back there. The number turtles that have arrived on beaches to lay eggs rose from a low of 2,633 in 1999 to 7,331 in 2004. Environmentalists attribut the sharp rise in recent years to the return of turtles that were born after the ban.

Echizen Kurage Giant Jellyfish

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giant jellyfish Echizen jellyfish are born in the spring along Chinese coasts in the Yellow Sea, as well as the East China Sea. They move north along the Tsushima Current and arrive in Japanese waters starting in mid-July. Afterward, they usually drift out into the Pacific Ocean via the Tsugaru Channel in early October. Some Echizen jellyfish have hoods two meters in diameter and weigh nearly 200 kilograms. [Source: Yomiuri Shimbun, September 26, 2012]

The Yomiuri Shimbun reported: “A research team led by Hiroshima University Prof. Shinichi Ue has conducted annual surveys of the number of jellyfish per 100 square meters in the Yellow Sea between June and November since 2006. The survey is used to predict how many jellyfish will arrive in Japanese waters.

In 2012, the team found 0.44 jellyfish per 100 square meters in July. The number is 730 times larger than the 0.0006 found in 2010, when hardly any jellyfish-related damage was reported, and about nine times larger than the 0.05 reported in 2011. Usually, the number of jellyfish found in the Yellow Sea peaks in July. However, the figure has remained high in 2012, registering between 0.2 and 0.5 in August and 0.16 in September. Compared to last year's figures, the number was 10 to 71 times larger in August and 2,285 times larger in September. The figures were close to those recorded years of jellyfish population explosions--0.21 in August 2007, 0.55 in August 2009 and 0.2 in September 2009. According to JF Shimane, a fisheries cooperative in Matsue, Echizen jellyfish are usually caught in fixed fishing nets in early and mid-August. However, in 2012, 20 to 150 jellyfish were caught daily in fixed nets of Okinoshima island, even in September.

A team of researchers from Hiroshima Institute of Technology created a one-meter-long, self-driving “jellyfish extermination device” to “suck and crush” the animals, before ejecting fragments of them back into the ocean. [Source: Joe Pinkstone, Julian Ryall, The Telegraph May 16, 2022]

Sightings of Poisonous Blue-Ring Octopuses on the Rise in Japan

In May 2012, the Yomiuri Shimbun reported: “Poisonous blue-ringed octopuses, which inhabit mainly tropical and semitropical zones in the Western Pacific, have been recently found in increasing numbers in the Kumano-nada area off the coast of southern Mie Prefecture. It is rare for blue-ringed octopuses, which carry tetrodotoxin, the same deadly poison present in fugu blowfish, to be found in the area during February and March when the weather is cold. [Source: Yomiuri Shimbun, May 30, 2012]

“An expert said, "Their habitat might have expanded north due to the rise in sea temperatures caused by global warming." An official of the Mie Prefecture Fisheries Research Institute in Shima found a blue-ringed octopus on the seafloor at a depth of 10 meters off the coast of Taiki, Mie Prefecture, on Feb. 16. Another was caught after being found on rocks about seven meters under water off Shima on March 7. Both octopuses were adults about 10 centimeters in length, the institute said. The octopuses' saliva contains tetrodotoxin, and anyone who is bitten will experience symptoms such as vomiting, paralysis and spasms.

The Asahi Shimbun reported: “Highly toxic blue-ringed octopuses that can kill a human with a single bite have been spotted recently in Kanagawa and Chiba prefectures, even though the small creatures normally inhabit waters near Kyushu and farther south. According to officials of the Research Institute of Marine Invertebrates in Tokyo’s Chuo Ward, the blue-ringed octopuses grow to about 15 centimeters long. While the animals are normally brownish in color and docile, they turn a brilliant yellow when attacked, and their bodies become covered with fluorescent blue spots. The octopus produces venom containing tetrodotoxin, the same toxin found in deadly fugu or blowfish. One or two milligrams of the venom can kill a human. “The octopuses normally inhabit reefs in subtropical regions stretching from Japan to Australia. However, the animals have been increasingly spotted in the Kanto region in recent years. [Source: Asahi Shimbun, June 21, 2013]

Crabs and Shellfish in Japan

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Japan's giant spider crabs duel with Alaska's king crabs for the honor of being the world's largest crustacean. According to the Guinness Book of Records, one giant spider crab weighed 41 pounds and had a claw span of 12 feet 1 inch.

Giant spider crabs are sometimes called the 'dead man's crab' for its habit of feeding on drowned bodies. Males have two penises. National Geographic writer Eugene Clark was snagged by the legs of one of these crabs. Each time she pried one leg loose another grabbed her, she said. But she never felt in danger and said it was like wrestling a giant sloth.

Shellfish yields have declined in some areas in the Seto Inland Sea as result of an influx of long-headed eagle rays, a species usually found in warmer tropical and subtropical waters. Global warming may explain the presence of these fish in waters off of Japan. Water temperatures in the Seto Inland Sea have risen 1 degree C in the past 30 years. The rays grow up to 1½ meters and weigh up to 50 kilograms and have venomous spine son their tails.

Sea Cucumbers and Japan

Soaring prices for sea cucumber from around ¥20,000 for kilogram of dried sea cumber to more than ¥70,000 have resulted in an increase in poaching of the sea creature, particularly around Hokkaido. The first known case of sea cucumber poaching was recorded in 2005. In 2006 a half dozen cases were reported, including one in which a gang of seven Hokkaido people was caught with 33 tons of sea cucumbers. Sea cucumbers from Hokkaido are preferred because their warts are said to be clearer and less unsightly.

Demand from China has cased the price and number of thefts of sea cucumber to rise in Japan. Prices are so high that thieves once broke into a sea cucumber processing plant in Morimach, Hokkaido, tied up factory employees and made off with 160 kilograms of dried sea cucumber. Sea cucumbers with long fat projections on the body, like those commonly found in Hokkaido, are especially valued in China. They used to be thrown away and fetched only ¥300 a kilogram in the mid 2000s but now sold for about ¥900 a kilogram in the early 2010s. . Sea cucumbers do not breed easily or quickly. Stocks have already been depleted. Some worry their populations maybe decimated beyond repair in a few years.

In July 2021, Japanese coast guard officers patrolling off the coast of Rumoi, Hokkaido at noght nabbed 11 men who were in the midst of stealing 680 kilograms (1,500 pounds) of sea cucumbers worth $20,000. Business Insider reported: “Sea cucumbers are a prized haul because of their prime status as a culinary delicacy in East Asia, particularly in China. Insider reported last year that sea cucumbers can cost over $3,000 a kilogram. Some spiky, fancier varieties are even packaged and gifted on special occasions. [Source: Cheryl The, Business Insider, July 12, 2021]

“The Rumoi coast guard told Hokkaido online news site UHB News Japan that some of the men were completely kitted out with full diving gear and submersible machines. They were part of a full operation complete with divers to go down and get the creatures, with lookouts keeping watch, as well as getaway cars.

Salmon and Eels in Japan

More salmon and trout spawn in the Sharigawa River on the Shiretoko Peninsula in northern Hokkaido. than any other river in Japan. The Shiretoko Peninsula is a UNESCO World Heritage Site. Officials in the region try very hard to keep salmon numbers up. Every year they catch salmon at a point about 1.2 kilometers from their rivers mouth, removes their eggs and artificially incubated them. After hatching the fry are released in the river.

Salmon poaching, to get the fish’s valuable eggs, is a problem on the Sharigawa River with eggs from wild salmon selling fr ¥2,800 a kilogram in 2007. Poaching groups are organized by local crime syndicates. There is a special unit of police that dress in black and are equipped with body armor and night vision scopes and stake out places where the salmon poacher seek their targets.

In February 2011, scientists at the University of Tokyo said the figured out the secret of eels spawning in the Pacific. The scientists collected eggs released shortly before the new moon in West Mariana Ridge area of the Pacific. Based on their size the scientists determined the eggs were probably fertilized about 30 hours earlier.

Image Sources: 1) Ray Kinnane 2) 6) Greenpeace 3) 5) Japan-Animals blog 4) Hector Garcia 7) 8) exorsyst blog, Wikimedia Commons

Text Sources: Animal Diversity Web animaldiversity.org ; National Geographic, Live Science, Natural History magazine, David Attenborough books, Daily Yomiuri, Yomiuri Shimbun, Japan National Tourist Organization (JNTO), New York Times, Washington Post, Los Angeles Times, Smithsonian magazine, Discover magazine, The New Yorker, Time, BBC, CNN, Reuters, Associated Press, AFP, Lonely Planet Guides, Wikipedia, The Guardian, Top Secret Animal Attack Files website and various books and other publications.

Last updated March 2025