California porpoise

from Wikipedia, the free encyclopedia
California porpoise
California porpoises

California porpoises

Systematics
Order : Whales (cetacea)
Subordination : Toothed whales (Odontoceti)
Superfamily : Dolphin-like (Delphinoidea)
Family : Porpoises (Phocoenidae)
Genre : Phocoena
Type : California porpoise
Scientific name
Phocoena sinus
Norris & McFarland , 1958

The California porpoise ( Phocoena sinus ), also known as the golf dolphin or vaquita , is a species of whale belonging to the porpoise family (Phocoenidae). It lives in only a small area in the northwest of the Gulf of California and is one of the most threatened mammal species, which is also underlined by the inclusion in the IUCN list of the hundred most critically endangered species. The species is particularly threatened as " bycatch " of the illegal hunt for the totoabas , a type of umber fish , that live in the same habitat .

features

With a length of 1.5 meters and a weight of around 50 kilograms, the California harbor porpoise is one of the smallest whales in the world , along with the La Plata dolphin and Hector dolphin . The females grow larger than the males. It is generally gray in color, although it is darker on the back than on the stomach. The eye and mouth gap are outlined in dark. Starting from the chin there is a gray stripe that widens towards the flippers . The pinball machines are small and wide. Compared to other porpoises, the triangular fin is quite large in relation to the body. The crescent-shaped fluke is notched and tapered to a point at the ends.

Way of life

California porpoises are primarily found in the northern part of the Gulf of California south of the Colorado Estuary. They prefer warmer waters than other porpoises, and the Gulf of California can get up to 36 degrees Celsius in summer. California porpoises live solitary or in pairs, and feed on cephalopods and fish .

Little is known about the reproduction of the California harbor porpoise. It is believed that the animals reach sexual maturity around the age of six. The mating season is in late spring, after a gestation period of ten to eleven months, the females give birth to a single young. In contrast to other porpoises, the females do not mate again until the following year.

habitat

The distribution of the California porpoise (light blue)

The habitat of the California porpoise is around 2235 km² off the east coast of Baja California . Since in 1993 only about 500 specimens of the California harbor porpoise existed, various organizations such as the ASMS or IFAW campaigned for the establishment of a marine reserve . After an area of ​​930,000 hectares was established, the establishment of further protected areas failed due to the commercial fishing industry, which had no interest in a ban on fishing.

In 1997 the population was again estimated to be less than 600, in 2012 to less than 200, in 2015 to less than 100 and in 2016 to only around 30 individuals. The cause of the reduction in the population is not considered to be genetic impoverishment , loss of habitat or environmental pollution, but the consequences of fishing: Every year up to 80 California porpoises perish as so-called bycatch in fishing nets. After the suspected extinction of the Chinese river dolphins reported in 2006, the California harbor porpoise is now considered the most critically endangered small whale . The IUCN lists it as critically endangered.

Campaigns for protection

Avaaz petitioned the Mexican government to ban gillnet fishing because California porpoises got caught in the nets and drowned. They refer to articles in time and in the world . In the fall of 2017, the attempt to capture the last surviving California harbor porpoises in order to save them from the fishermen's illegal Totoaba gill nets failed. After the first whale caught had to be released again because of its panic and the second had perished due to stress, the project was discontinued without result.

Sea Shepherd has been trying to save the species with Operation Milagro since 2014 . Mainly the organization sails with four ships, the Farley Mowat , the John Paul DeJoria , the Sharpie and the White Holly patrol in the area and removes illegally set up gillnets there.

On March 21, 2019, the Mexican government approved a protection zone off the west coast of Mexico for the last estimated 10 to 15 California porpoises.

As reported in Royal Society Open Science , there were fewer than 19 California porpoises in 2018. That emerges from the evaluation of the recordings from underwater microphones. However, only six animals were sighted that year, including a female with a calf.

The actor Leonardo DiCaprio is committed to the protection of the species and in 2019 made a documentary entitled Sea of ​​Shadows about efforts to save the vaquitas.

Duration

According to press reports at the end of 2019, according to records from Mexican environmental protection organizations, the number of animals living in the wild is only 19 specimens.

literature

  • Gerhard Schulze: The porpoises. Family Phocoenidae . In: New Brehm Library . 2nd Edition. tape 583 . Westarp Sciences, Magdeburg 1996, ISBN 3-89432-379-5 .

Web links

Commons : Phocoena sinus  - Collection of images, videos and audio files

Individual evidence

  1. ^ Cetacean Specialist Group: Phocoena sinus . In: JEM Baillie, ER Butcher (Eds.): Priceless or Worthless? The world's most threatened species. Zoological Society of London, 2012, ISBN 978-0-900881-67-1 , pp. 56–57 (English, online [ADOBE Flash ; accessed November 28, 2017] IUCN information sheet ).
  2. ↑ a b Badische Zeitung: The greed sacrificed - Panorama - Badische Zeitung. Accessed December 30, 2019 .
  3. ↑ a b c Species portrait Vaquita (Phocoena sinus). (PDF) WWF Germany, accessed on June 30, 2016 .
  4. ^ Allie Wilkinson, Disappearing Porpoise: Down to 97 and Dropping Fast. In: The New York Times. June 19, 2015, accessed February 13, 2016 .
  5. ↑ Virginia Morell: World's most endangered marine mammal down to 30 individuals . In: Science . tape 355 , no. 6325 , February 10, 2017, p. 558-559 ( full text ). doi : 10.1126 / science.355.6325.558
  6. ↑ Lorenzo Rojas-Bracho et al: Conservation of the vaquita 'Phocoena sinus' . In: Mammal Review . tape 36 , no. 3 , 2006, p. 179-216 . doi : 10.1111 / j.1365-2907.2006.00088.x .
  7. ↑ Phocoena sinus in the endangered Red List species the IUCN 2008. Posted by: Lorenzo Rojas-Bracho and others, 2008. Accessed January 2 of 2009.
  8. ↑ Mexico: Save the Vaquitas. In: AVAAZ. Retrieved November 28, 2017 (online petition).
  9. ^ Fritz Habekuss: Species extinction: The last mini whales. In: ZEIT Online. February 4, 2016. Retrieved November 28, 2017 .
  10. ↑ Smallest porpoise almost extinct. In: WELT Online. February 8, 2017. Retrieved November 28, 2017 .
  11. ↑ Philip Bethge: Protection of species: Requiem for the Vaquita . In: Der Spiegel . No. 47 , 2017, p. 110-113 ( Online - Nov. 18, 2017 ).
  12. ↑ euronews - Only 10 of their kind left: Mexico wants to save harbor porpoises (March 23, 2019)
  13. ↑ a b Nick Kaiser: Only 19 of their kind . In: Halterner Zeitung , July 31, 2019