On November 13, 2011, Cove Guardians witnessed how a family of eighteen Risso’s dolphins was driven into Taiji’s infamous cove. Among the pod the observers noticed two dolphins that were distinctly different from the relatively large-bodied, scarred, grey-and-white Risso’s. Instead of the rounded melons that Risso’s have in common with pilot whales and other members of the blackfish family, these dolphins had tapered, conical heads ending in a slender beak-like rostrum, unlike any other dolphin.
This made it easy to identify them as rough-toothed dolphins. This dolphin is the only member of the genus Steno, fossils of which date back to the Plioceen, a geological period of 2½ to 5 million years ago. It is a relatively large dolphin, between two and three meters long and up to 150 kilos in weight, with a high dorsal. Compared to other dolphins, the flippers are set back further along the body. The gray skin, dark on the back and lighter on the sides, is at a later age often covered in pale white to pink spots and sometimes scarred. The bottom side including the lower jaw is often white. Vertical grooves in the crowns of the 20 to 27 teeth per jaw, explain the name rough-toothed dolphin. They eat fish and squid.
Of the mixed pod captured in the bay of Taiji that november, ten of the larger Risso’s dolphins were stranded on the pebble beach of the Cove and killed by driving a steel rod into their necks; their lifeless bodies were dragged to the butcher house to be cut up into pieces, to be auctioned off by the Fishermen’s Union to merchants owning small butcher shops where the meat is cut into slices and the blubber is boiled to crisps in oil to supply the local shops. The stench of boiling fat, like every slaughter day during the September to March dolphin drive-hunt season, would soon engulf the entire town.
The remaining eight undesirable Risso’s and the two rough-toothed dolphins were driven back to the open sea. The rough-toothed dolphins had to be released as the dolphin-killers did not have an assigned quota for this species, but that, if reports in the Japanese press are to be believed, is about to change.
For many years now the quota for the Taiji drive-hunt has consisted of seven species:
- Striped dolphins
- Pacific bottlenose dolphins
- Pacific white-sided dolphins
- Pantropical spotted dolphins
- Risso’s dolphins
- Short-finned pilot whales
- False killer whales
On May 30, the Japanese Fisheries Agency reportedly approved the inclusion of two additional species for capture and/or slaughter for the 2017-2018 dolphin drive-hunt season:
- Rough-toothed dolphins
- Melon-headed whales
Regarding the numbers, it was previously reported that the Fisheries Agency was considering the addition of 46 rough-toothed dolphins and 704 melon-headed whales to the combined quotas of Wakayama Prefecture – that is Taiji – and Okinawa Prefecture, where a hand-held harpoon hunt is practiced. These numbers have not yet been confirmed and quotas are usually only released a couple of weeks before the September 1 opening of the drive-hunt season.
The relatively low number of rough-toothed dolphins indicates that the main purpose might be live-capture for marine circuses. Only a handful of rough-toothed dolphins are kept in captivity today, but reportedly they ‘adapt’ well. Several Florida ‘rescues’-from-the-wild, live at Gulf World Marine: Doris and Ivan (since September 2004), Largo (since March 2005), Astro (since April 2005), Kitana (since August 2009) and stan (since June 2015). Okinawa Churaumi Aquarium in Japan apparently has one rough-toothed dolphin on display.
Rough-toothed dolphins live in pods of ten to twenty animals, but several of these family groups can come together and form a pod of several hundred, so just one or two drives of this species could fill that rumored quota. These dolphins, just like the other newly targeted dolphin, the melon-headed whale, has a preference for deep tropical and subtropical waters and are therefore rarely seen. They are known from the north of the Gulf of Mexico and the Honduran island of Utila, the Brazilian coast, Hawaii, Tahiti and Moorea, the West African coast including the Canary Islands and Cape Verde and the Mediterranean Sea between Malta and Israel.
They are also seen on the whale watching trips of Nanki Marine Leisure Service, a small business located in the tiny port of Ugui, between Shingu and Katsuura, just north of Taiji. Cetaceans seen on their trips include: dwarf sperm whale, sperm whale, Risso’s dolphin, bottlenose dolphin, short-finned pilot whale, false killer whale, pygmy killer whale, melon-headed whale and rough-toothed dolphin.
Rough-toothed dolphins like to interact with other dolphin species as the November 2011 Taiji example shows, when consorting with Risso’s got two rough-toothed individuals into trouble. The scientific literature further mentions bottlenose dolphins, pilot whales, spinner dolphins and Fraser’s dolphins as rough-toothed companions and I saw them in combined pods of melon-headed whales in the Gulf of Mexico and with pantropical spotted dolphins at Ascension Island.
The exact size of their distribution is unknown. We know so little of this species that researchers write scientific articles about the ‘Finding of a dead rough-toothed dolphin Steno bredanensis (Cuvier and Lesson,1828), stranded on the south Morrocan coast’ and of casual encounters with these dolphins by Dutch (‘Opportunistic feeding behaviour of rough-toothed dolphins Steno bredanensis off Mauritania’) and American (‘Observations of rough-toothed dolphins (Steno bredanensis) off the coast of Utila, Honduras’) researchers.
Although we know almost nothing about the animals, not even abundance estimates, rough-toothed dolphins are not considered an endangered species. There are, however, various threats that apply to all dolphins: they get entangled in fishing nets, especially in those of tuna seiners, in their blubber and organs the animals bio-accumulate pollutants, sometimes plastic is ingested mistaken for food, overfishing threatens their food supply and underwater noise causes stress or worse. In a mass-stranding event of 69 rough-toothed dolphins on the Island of Marathon in the Florida Keys in 2005, in which 36 animals died, sonar of the submarine USS Philadelphia was indicated as a possible cause, but so was malnutrition.
The high number of melon-headed whales in the suspected quota as published, offers the opportunity for a combination of enslavement for the entertainment industry and murder for consumption, but most likely the latter. The Japanese around Taiji seem to have a taste-bud-preference for ‘blackfish’ such as Risso’s and pilot whales. Melon-headed whales are also considered part of this subfamily Globicephalinae that further includes the orca and false killer whales.
Like rough-toothed dolphins, melon-headed whales are not often seen as they prefer deep-offshore waters. Likely they occur throughout the world in tropical and subtropical waters in groups of several hundred to 1000 animals. They are known from areas where deep oceanic waters are found close to land such as around the Philippine island of Cebu, the Caribbean island of Dominica and Hawaii.
The accompanying photos were taken in the Gulf of Mexico, about 100 miles south of the Mississippi estuary and in Lombok Strait in Indonesia.
Melon-heads have torpedo-shaped bodies and a rounded foreheads explaining the English name, but not as pronounced as most other Globicephalinae. The body is gray with a dark-gray facemask with white lips and a dark band over the back. They have long pointy flippers and a relatively large pointed dorsal. They are nearly three meters long and can weigh more than 200 kilograms. They eat mainly squid and small fish.
As with the rough-toothed dolphins, we don’t know much more about them, but we do know from experience what threatens this species:
In July 2004, 150 to 200 melon-headed whales swam into Hanalei Bay in the north of the Hawaiian island of Kaua’i. One day later, they were driven back to open sea with help from the local people. A calf stayed behind and died. According to NOAA, sonar-use by American Navy ships during a nearby exercise was the likely cause of the stranding.
A similar event took place in February 2009 in the Philippines when 200 to 300 melon-headed whales swam into Manila Bay and stranded on the Bataan Peninsula. The inhabitants of the villages Pilar and Abucay came to the rescue and in this case too most dolphins were driven back to open sea. Three melon-heads died, two of whom reportedly had damaged eardrums.
This could be caused by underwater noise from natural sources such as seaquakes, but also by military sonar or seismic research. This vulnerability to anthropomorphic sound is used by the Taiji ‘banger boats’ to drive dolphins.
There exists one other place where melon-headed whales were regularly hunted: the Solomon Islands. Locally referred to as Robo au (sharp), Robo tafungai (real) and Robo gou tori (flat head), the melon-headed whale was formerly the most important target for the dolphin hunting villages as their teeth were the most highly-prized.
The main objective of the drive hunts in the Solomon Islands is to collect dolphin teeth for their use as traditional currency, for bride prices, compensation payments, settling of disputes, fines, reciprocal gifts, purchasing of land, adornment, services of priests and others and, more recently, for cash sale. Young girls are adorned with shell beads and dolphin teeth and young boys and their parents collect teeth to take these girls for wives. Dolphin teeth connected and to some extent still connect the people of the area.
Walande and Sulufou villagers recorded the last Robo au catch in 1978.
The catch rate in the Solomon Islands has been highly variable throughout history, but the noticeable increase during the 1960s, as reported by Dawbin in 1966, probably resulted in the local extinction of the melon-headed whale. This should be a grim warning to the Japanese.
Not surprisingly the news of additional huntable species was welcomed in Taiji. The Taiji Whale Museum immediately expressed interest in displaying these new additions and to include them in the ‘Sea of Whales’ breeding program, a repeatedly announced desire of the town to net off Moriura Bay and turn it into an enormous dolphin-circus and breeding-farm for different species of dolphin. At some point even the inclusion of minke whales was mentioned. All the enthusiasm is presented disguised as an opportunity for academic research, a favorite among captive display facilities around the world, and the sustainable management and effective use of marine resources.
That science or sustainability are not part of the Japanese methodology, becomes clear when you look at the catch figures. There are no abundance estimates of cetaceans along the Japanese Pacific coast to base quota on. With the exception of Risso’s dolphins, the Taiji hunters have not been able to fill any of the quotas this millenium. False killer whales have not been caught since 2011, but the quota of 70 stands year after year. The Pacific white-sided dolphin quota is repeatedly set at 134 individuals, but only a handful is actually caught. This inability to fill quota might not only be an indictor of dwindling cetacean numbers migrating through Japanese waters, but could also be one of the reasons behind the expansion of the humber of species that can be caught.
The Taiji dolphin drive-hunt and the captive industry represent two sides of the same cruel coin. They are unacceptable in their current form and will remain contested, barbaric practices with the added species.
Don’t buy a ticket to a dolphin show!
Until all the tanks and cages are empty!
In Dutch: https://www.animalstoday.nl/erwin-vermeulen-taiji-nieuwe-soorten-drijfjachtquota/
Finding of a dead rough-toothed dolphin Steno bredanensis (Cuvier and Lesson, 1828), stranded on the south Morrocan coast – A. G. de los Ríos y O. Ocaña
Opportunistic feeding behaviour of rough-toothed dolphins Steno bredanensis off Mauritania – M.J. Addink & C. Smeenk