“With as few as 10 vaquitas left, the species will become extinct without a fully enforced gillnet ban…”[i]
The extraordinary vaquitas are a species of porpoise endemic to the Californian Gulf. They are famously known to be the smallest marine mammal in the world, measuring at less than 1.5meters, and weighing around 45kgs[i]. Unfortunately, they are critically endangered as they typically get caught as bycatch. The local fishermen aren’t trying to sweep up the playful porpoises in their nets, instead they’re looking for the valuable fish, Totoaba (Totoaba macdonaldi). This species is hunted for their swim bladder, themselves ending up endangered in the process. There has been much political debate about how to sustainably fish in the northern Mexican waters, whilst still providing enough income for the local communities.
This blog post will explore a newly published research article spearheaded by Dr. Miguel Cisneros-Mata, exploring the survivability potential of the vaquita in the Californian Gulf. The purpose of this research is to understand the main drivers of the species decline, and help change the Totoaba fishing policy in Baja Californian waters. The article is called: Viability of the vaquita (Phocoena sinus) Cetacea: Phocoenidae) population, threatened by poaching of Totoaba macdonaldi (Perciformes: Sciaenidae)[i].
“The only proven source of vaquita mortality is incidental take in gillnets and a small proportion in trawl nets.”[i]
Fishermen’s attempts to survive in a competitive environment over the past 70 years became the downfall of the vaquita. The fishing of Totoaba was made illegal in 1975, however this did not stop poachers from pursuing them[i]. The vaquitas were once upon a time thriving in their local environment, surpassing an estimated population count of 1000 in the 1950s. Despite some people’s best interests and donations, the population gradually declined over the years. At the stage we are at now, it is hard to see how these beloved porpoises can make a comeback. They are quite literally only a handful of fishing accidents away from extinction.
Evaluating the vaquitas viability
So how do you go about determining if the vaquitas have a genuine shot at survival? Well, the article explains that we need to consider historic literature and data, as well as make a few assumptions. Please stay with me through explanation of some relevant terminology. One of the assumptions that had to be made was that the chance of an increase in population was severely dependent on demographic stochasticity (a.k.a. chance events). Another assumption based on the Allee effect was that whenever a mother died, its calf would suffer the same fate. The analysis made use of an advanced life table, which in a nutshell shows the probability of an individual’s death, based on its age. The probability rates of the life table were taken from two other porpoise species in North America that are closely related to the vaquita. Another variable used in the formula was the reproductive rates of an individual at every age. The final critical assumption was that from the point of calculating, 2019, there would be no recorded vaquita mortalities through bycatch.
There is still hope!
The modelled projections filled researchers with hope and determination as reproductive rates were solid enough to maintain a sustainable population given sufficient time.
The values from the analytical results emphasise how important it is that all Totoaba fishing in the critical area stops immediately, should the vaquitas have a second chance at life.
“Demographically, the vaquita population seems viable even at extremely low numbers; its genetic makeup will be the factor governing its long-run viability.”[i]
A key variable that could see the vaquitas make a comeback is their genetic coding. As long as the population count doesn’t stay stale or decrease, they have all the resources they need to make it.[i]
Without human disturbance, the vaquitas can make a recovery. Clearly the species can survive on its own. But even with human farm and release programs, the bycatch mortality rates are just too high. We need to implement a complete gillnet ban in the northern Californian Gulf. It is our duty as humans to preserve the endangered, especially seeing as their blood is on our own hands.
How can YOU save the vaquita?
Even though you most likely don’t live in northern Mexico, there are still plenty of things you can do to help these precious animals.
Donate Money: You can donate to trustworthy conservation organisations such as WWF’s “Adopt a vaquita” initiative for example. Here are links to WWF and Viva Vaquita’s trustworthy donation sites: WWF, https://gifts.worldwildlife.org/gift-center/gifts/Species-Adoptions/Vaquita.aspx Viva Vaquita, https://vivavaquita.org/donate-to-the-vaquita-recovery-fund/
Sign Petitions: It is totally fine if you can’t afford to donate your money to a cause. A free alternative is to sign a petition trying to fight for the vaquitas rights, and end Totoaba fishing once and for all. Here is a link to one of these petitions by change.org: https://chng.it/TWnmQdbN6g
Spread the Word: Educate yourself about the issue, tell your friends, share links, write a blog about it! Celebrate the International Save the Vaquita Day on July 8. Any little thing will help the cause. Changing one person’s mind is like pushing the first piece of an infinite line of domino blocks.
[i] (Barbara & Rojas-Bracho, 1999).
Barbara, T. L., & Rojas-Bracho, L. (1999). EXAMINING THE RISK OF INBREEDING DEPRESSION IN A NATURALLY RARE CETACEAN, THE VAQUITA (PHOCOENA SINUS)1. Marine Mammal Science, 15(4), 1004-1028. Retrieved from https://doi.org/10.1111/j.1748-7692.1999.tb00875.x
Cisneros-Mata, M. A., Delgado, J. A., & Rodriguez-Felix, D. (2021). Viability of the vaquita, Phocoena sinus (Cetacea: Phocoenidae) population, threatened by poaching of Totoaba macdonaldi (Perciformes: Sciaenidae). Revista de Biologia Tropical, 69(2), 588-600. doi: 10.15517/rbt.v69i2.4547
Mexico News Daily. (2021, 07 21). Vaquita porpoise sacrificed for political gain; observers fear extinction will follow. Retrieved from https://mexiconewsdaily.com/news/vaquita-porpoise-sacrificed-for-political-gain-extinction-feared/
NOAA. (2021). Vaquita. Retrieved from NOAA Fisheries: https://www.fisheries.noaa.gov/species/vaquita
PeppermintNarwhal. (n.d.). Retrieved from RedBubble: https://www.redbubble.com/people/PepomintNarwhal/shop
SeaWorld Parks and Entertainment. (2021). Vaquita. Retrieved from seaworld.org: https://seaworld.org/animals/facts/mammals/vaquita/#:~:text=The%20largest%20vaquita%20ever%20measured%20was%20a%20mature,of%20benthic%20fishes%2C%20squids%2C%20and%20crustaceans.%20Life%20Span.
Starkey, S. (2017, 10 July). 30 Vaquitas. Retrieved from medium.com: https://medium.com/@savannahstarkey/30-vaquitas-1529831cba3e
WWF. (2021). Dolphins and Porpoises: Vaquita. Retrieved from worldwildlife.org: https://www.worldwildlife.org/species/vaquita
[i] (Cisneros-Mata, Delgado, & Rodriguez-Felix, 2021)