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|Vaquita - Phocoena sinus|
|Tweet Topic Started: Jan 9 2012, 11:42 AM (9,530 Views)|
|Taipan||Jan 9 2012, 11:42 AM Post #1|
Vaquita - Phocoena sinus
Species: Phocoena sinus
Cochito, Gulf of California Harbor Porpoise, Gulf of California Porpoise, Gulf Porpoise, Hafenschweinswal, Marsouin du Golfe de Californie, Vaquito
Description & Behavior
The vaquita, Phocoena sinus (Norris and McFarland, 1958), aka Gulf of California harbor porpoise, reaches 1.2 to 1.5 m in length and averages 55 kg; females are slightly larger than males. They have between 34-40 "acorn-like" teeth in the jaws of their blunt-shaped beak. Vaquitas are similar in shape and size to the harbor porpoise, Phocoena phocoena, with the exception of the more slender body shape of the vaquita. Their slender shape is thought to facilitate heat dissipation in the warm waters they inhabit.
Vaquitas have been observed both singly and in small groups, which suggests that they are a less gregarious dolphin species, and perhaps more competitive during mating season.
Like many other phocoenids and delphinidids, the vaquita uses sonar as a means of communicating with other vaquitas and navigating through its habitat.
World Range & Habitat
The vaquita, Phocoena sinus, is found only in the northern area of the Gulf of California in coastal, shallow water. Vaquitas are the only porpoise species found in such warm waters. Most phocoenids inhabit waters cooler than 20°C. Vaquitas are able to tolerate the fluctuations in temperature in the Gulf of California that range from 14°C in January to 36°C in August.
Feeding Behavior (Ecology)
The vaquita, Phocoena sinus, feeds on teleost (bony) fishes and squid found near the surface of the water.
The vaquita, Phocoena sinus, reaches sexual maturity between 3-6 years. Females do not ovulate annually, therefore they do not give birth each year. They reproduce seasonally from mid-April to May, with a gestation period of about 10.6 months. Males mate with as many females as possible. Similar to other mammals with multi-male breeding systems, male vaquitas have large testes relative to their body size. Females give birth to 1 calf per pregnancy that averages in size from 0.6-0.7 m in length. Calves are nursed for <1 year. Juvenile vaquitas can be identified by the white spots on their dorsal fins.
The vaquita, Phocoena sinus, is listed as critically endangered, and only several hundred remain. They often suffer from entanglement in fishing gear, particularly shrimp nets and gillnets set for sharks. An estimated 25-30 vaquitas drown each year as a result. Juveniles are particularly at-risk, which further threatens the sustainability of this species as the number of reproductive adults is reduced. They are also at-risk because of their similarity in size to a popular seabass like fish called Totoabo. Although fishing for Totoabo is illegal, it continues to heavily exploited, which threatens both vaquitas and Totabo.
Data on Biology and Ecology
Size and Weight:
Length: Females - up to 1.5 m (5'); males - up to 1.4 m (4.6'). Weight: up to 55 kg (120 lb).
The vaquita lives in shallow lagoons along the shoreline. It is usually found in waters 10 - 28 m (33 - 92') deep within 25 km (16 mi) from shore, although it can survive in lagoons so shallow that its back protrudes above the water. Other characteristics of its habitat are strong tidal mixing and high productivity of the aquatic plant and animal communities. (Carwardine 1995, Culik 2003)
It occurs in the Sea of Cortez Global 200 Ecoregion. (Olson & Dinerstein 1998, Olson & Dinerstein 1999)
Age to Maturity:
Females may become sexually mature at a length of approximately 1.3 m (4.4').
The gestation period is probably 10 - 11 months (Culik 2003).
Births are thought to occur generally around late March or early April.
A female probably produces 1 calf annually.
A vaquita calf is weaned after several months (Burnie & Wilson 2001).
The maximum observed age is 21 years (Culik 2003).
All of the 17 fish species found in vaquita stomachs can be classified as demersal and/or benthic species inhabiting relatively shallow water in the upper Gulf of California. It appears that the vaquita is a rather non-selective feeder on small fish and squid. Squid remains were also found in several stomach samples. (Culik 2003)
The vaquita appears to swim and feed in a leisurely manner, but it is elusive and will avoid boats of any kind. It rises to breathe with a slow, forward-rolling movement that barely disturbs the surface of the water, and then disappears quickly, often for a long time. (Culik 2003) It uses high-frequency clicks for echolocation. (Burnie & Wilson 2001)
The vaquita occurs singly or in small groups. One report indicated that in 58 sightings, 91 % comprised from one to three individuals, with a mean group size of 1.9 and a range of 1 - 7. Loose aggregations of vaquitas, in which they were dispersed as single individuals or as small subgroups (from two to four members, greatest number eight to ten) throughout several hundred sq m (several thousand sq ft) were also reported. (Culik 2003)
Mortality and Survival:
The total estimated incidental mortality caused by one fishing fleet in the Gulf of California was 39 vaquitas per year (95% CI = 14 - 93). (D’Agrosa et al. 2000)
Edited by Taipan, Aug 14 2014, 01:06 PM.
|Taipan||Jan 11 2012, 08:34 PM Post #2|
World’s Rarest Cetacean, the Vaquita Porpoise, Slipping Towards Extinction.
January 2008. An international research team, including biologists from NOAA’s Fisheries Service, reported in the scientific journal Conservation Biology, that the estimated population of vaquita, a porpoise found only in the Gulf of California, is probably just two years away from reaching such low levels that their plunge towards extinction will increase and possibly be irreversible. Scientists believe only about 150 vaquita remain.
Approximately 30 vaquita drown each year in the Gulf of California when they become entangled in nets set for fish and shrimp.
The vaquita is one of EDGE's target species. The EDGE of Existence programme aims to conserve the world's most Evolutionarily Distinct and Globally Endangered (EDGE) species by implementing the research and conservation actions needed to secure their future.
Vaquita are found only in a small area of productive, shallow water in the northernmost Gulf of California. They are listed as endangered species by the United States and Mexico and critically endangered by the World Conservation Union.
Following the Baiji to Extinction
Researchers cite worrisome parallels between vaquita and the baiji, a freshwater dolphin in the Yangtze River, which was recently declared likely to be extinct; primarily from entanglement in fishing gear.
The research team, led by Armando Jaramillo, Instituto Nacional de Ecología, Mexico, included researchers Barbara Taylor, NOAA’s Fisheries Service, and Randy Reeves Reeves, Chair of the Cestacean Specialist Group, IUCN – the World Conservation Union. The group assessed the number of vaquita based on past estimates of abundance and deaths in fishing nets together with current fishing effort.
|hawkkeye||Jul 2 2014, 10:13 PM Post #3|
At http://www.macroevolution.net/porpoise-hybrids.html#.U7P-HrGltJI author wrote that the Vaquita is a hybrid species or hybrid population between burrmeister and harbor porpoise. Have someone more info about it please?
Edited by hawkkeye, Jul 4 2014, 01:10 AM.
|Taipan||Aug 14 2014, 01:12 PM Post #4|
Vaquita Porpoise Faces Imminent Extinction—Can It Be Saved?
Drastic measures are needed to rescue vaquitas in the Gulf of California.
Only 97 vaquita porpoises remain in the wild. Their steep decline is blamed largely on illegal gill-net fishing in the Gulf of California.
for National Geographic
PUBLISHED AUGUST 13, 2014
The vaquita, a small porpoise found only in the Gulf of California, is rapidly going extinct, an international team of scientists reported earlier this month.
The researchers say that the marine mammals—whose name means "little cow" in Spanish—are accidentally drowning in the gill nets local fishers deploy for fish and shrimp. A mere 97 vaquitas remain.
Vaquitas are shy creatures, and rarely seen, except when they're pulled to the surface—dead—in nets. They've been known to science only since 1958, when three skulls were found on a beach. At the time, it was thought that they numbered in the low thousands. Scientists and fishers alike say the animals, with their pretty facial markings ("they look like they're wearing lipstick and mascara," one scientist said) and sleek bodies, are endearing.
There's danger now that the porpoises will become the second cetacean (the first was the baiji, or Chinese river dolphin) to succumb to human pressures, most likely disappearing forever by 2018.
"It's a complete disappointment for everybody, because we've all been working hard to turn this around, and the [Mexican] government has addressed this from the highest level possible," said Lorenzo Rojas-Bracho, a cetacean conservation specialist at Mexico's Commission of Natural Protected Areas and a member of the team.
Indeed, the Mexican government established a presidential commission on vaquita conservation in 2012, when scientists estimated the porpoise's population at 200.
MAGGIE SMITH, NG STAFF. SOURCES: INTERNATIONAL COMMITTEE FOR THE RECOVERY OF THE VAQUITA; IUCN; UNEP-WCMC
To stem the vaquitas' decline, in 2005 Mexico created a refuge for them, banned all commercial fishing in the refuge's waters, beefed up enforcement, and invested more than $30 million (U.S.) to compensate fishers and encourage them to switch to other fishing methods.
It also established the international scientific team to monitor the porpoise's population, reproductive rates, and habitat. Its members hail from such august conservation bodies as the International Union for Conservation of Nature, the International Whaling Commission, the U.S. Marine Mammal Commission, and Norway's Institute of Marine Research.
All were optimistic then. "We thought we were going to see the vaquitas' numbers increasing by 4 percent a year," said Barbara Taylor, a marine biologist with the Southwest Fisheries Science Center in San Diego, California, and a member of the team. "Instead, they've had a catastrophic decline of 18.5 percent per year."
Chinese Demand—But Not for Vaquitas
That decline, Rojas-Bracho said, is "all due to illegal fishing that is out of control."
In the past three years, illegal gillnetting for the totoaba, a critically endangered fish that can grow to more than six feet long (1.8 meters) and 300 pounds (136 kilograms), has surged. Unfortunately, the porpoise and the similarly sized totoaba live in the same parts of the gulf.
The totoaba's swim bladder, highly prized as a traditional health food and medicine in China, can fetch thousands of dollars. Few fishers can resist the temptation.
"It's like trying to control traffic while someone's throwing money from the Empire State Building," said Rojas-Bracho, who learned of the extent of this illegal take from several fishers who are also on the presidential commission.
The team estimates that about 435 miles (700 kilometers) of legal nets are in the water every day during the fishing season, from mid-September to mid-June. "And that's not counting the illegal nets for the totoaba," Taylor says.
Because of the vaquita's timid nature (a sighting at 300 feet [90 meters] is considered close), scientists can't make visual counts of the animals. They rely instead on an array of special acoustic devices, deployed every year before the fishing season begins (they too are easily tangled in the nets), to record the sounds of the animals as they forage in the murky waters they favor. From these sounds, the researchers are able to estimate the vaquitas' numbers.
Because the animal's population is so low, the team says there is only one solution: Ban all gillnetting in the gulf's upper regions, including the waters surrounding the vaquitas' refuge. The ban must be strictly applied, even to the legal shrimp and fin fish fishery, and enforced with more police patrols on sea and land.
"It's a hard choice," Taylor acknowledges. Such a ban will hurt all the fishers, including those who aren't engaged in the illegal fishery. But, she said, if Mexico doesn't do that, it "will lose the vaquita."
Rojas-Bracho said that Mexico, China, and the United States governments also need to work together to control—if not end—the trade in totoaba swim bladders. The dried bladders are often smuggled across the U.S. border before ending up in the Chinese marketplace.
There is a modicum of hope. Even at only 97 animals (25 of them believed to be females of reproductive age), the species can still be saved, Taylor believes. "Most marine mammals, including other cetaceans, that have been taken down through hunting have come back, so it's not too late. But if nothing is done, they can also go extinct rapidly, as happened with the baiji. They can be gone before you know it."
The commission will meet again at the end of August to discuss what to do next to save the vaquita.
|Sicilianu||Aug 18 2014, 06:56 AM Post #5|
|So sad. It seems it will end up like the yangtze river dolphin. I wonder if it would be more prudent to catch them and keep them in a captivity.|
|Fist of the North Shrimp||Aug 18 2014, 07:21 AM Post #6|
vá á orminum
|Interesting how something from the other half of the globe is considered TCM.|
|Koolyote||Aug 19 2014, 10:47 PM Post #7|
That's what I thought.
I hope there will be a solution to avoid this specie's near extinction.
|Thalassophoneus||Dec 31 2015, 06:15 AM Post #8|
|It really frustrates me that fishermen in the conservation area keep fishing without carring about this species. I mean apparently the best way to help endangered cetaceans is confiscation of fishing boats and imprisonment of whalers! When a species is threatened you can't be like "it's just one species, you don't need it, I'll just be carefull"!|
|SETA222||Mar 22 2017, 05:33 AM Post #9|
"Sea Shepherd Discovers Dead Vaquita Floating In Gulf of California
Death bring world’s smallest porpoise closer to extinction
San Felipe, Baja California, MEXICO – March 21, 2017 – Sea Shepherd found the body of a dead vaquita porpoise floating in the Gulf of California on Sunday March 19, 2017.
The non-profit marine conservation society has been in the upper Gulf since last fall as part of Operation Milagro III to save the vaquita and the endangered totoaba bass. Sea Shepherd’s anti-poaching ships, the M/V Farley Mowat and M/Y Sam Simon are currently patrolling the area.
At 2:47pm on Sunday, the Farley Mowat crew came across the dead vaquita – known as the world’s smallest porpoise – and notified the Mexican authorities to retrieve it. The carcass is currently being held in San Felipe, frozen, awaiting an examination to determine its cause of death.
With the near-extinct vaquita porpoise now numbering less than 30, the devastating sight comes exactly one week after Sea Shepherd found a dead newborn vaquita on the beach just 33 km south of San Felipe.
“Witnessing one of the few remaining vaquita in the entire world dead and floating in front of our ship was devastating to my crew,” said Farley Mowat Captain Luisa Albera. “We are continuing to stay focused on retrieving all nets that are trapping the vaquita to death.”
Over the weekend, the Farley Mowat and Sam Simon recovered 11 illegal totoaba nets. These nets are the most common cause of death for the vaquita as it entangles the porpoise, causing it to drown.
These nets are set up by illegal fisherman to trap the totoaba and export its swim bladder for sale on the black market in China and Hong Kong. There it is prized for unsubstantiated medicinal properties and can fetch more than $20,000 per kilo. Due to this high street value, the totoaba bladder is frequently referred to as “aquatic cocaine” and is the only reason this fish is being killed.
“The illegal trafficking of totoaba swim bladders in the Gulf of California is at an all-time high. If things continue at this rate, there is little hope for the vaquita’s survival,” said Operation Milagro III Campaign Leader and Sam Simon Captain Oona Layolle. “It is depressing to witness the extinction of a species due to human greed. Despite the devastating deaths seen in the past week, Sea Shepherd’s relentless work in the Gulf continues to save many marine animals’ lives and we will continue to defend, conserve and protect the marine life here including the vaquita.”
( more pics in link )
|Thalassophoneus||Mar 22 2017, 03:07 PM Post #10|
Why haven't people just started boicotting the fishing from that area?
|Scalesofanubis||Mar 23 2017, 12:43 AM Post #11|
Somehow I doubt that if you are into black market swim bladders you are super concerned with vaquitas.
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