A Whale Shark Tale: The Gulf of California

As I covered last week, ecotourism is a rapidly expanding global industry and has the potential to be beneficial for wildlife, local peoples, and conversation initiatives. Wildlife ecotourism is becoming increasingly popular as tourists are seeking out exotic charismatic animals across the globe.

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Penguin ecotourism [Digital Image] (n.d.). Retrieved from http://www.takepart.com/

Whale sharks (Rhincodon typus) are incredibly impressive sharks, reaching lengths over 40 feet and weighing in at nearly 60 tons (Campagno, 2001; Skomal, 2016)! These massive filter feeders are found in tropical and subtropical hot spots around the globe, including Western Australia, Maldives, Belize and Mexico (Martin, 2007). Next week I will be traveling to La Paz, Baja California Sur, Mexico to work with these amazing animals! Be sure to check back for posts from La Paz!

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Robinson, D. (Photographer). (2016). Whale shark [Digital Image]. Retrieved from https://www.nationalgeographic.com/

One of the most accessible places for swimming with whale sharks is in the Gulf of California. Whale sharks seasonally aggregate in several bays throughout the Gulf of California coinciding with plankton blooms (Martin, 2007). Whale sharks have also been observed feeding on coral spawn, snapper spawn, and the megalopa of terrestrial crabs (Graham & Roberts, 2007; Heyman, Graham, Kjerfve, & Johannes, 2001; Martin, 2007). These sharks swim slowly near the surface feeding on this microscopic prey. This seasonal predictability of aggregations within the region has led to a large ecotourism industry in Baja California Sur, Mexico.

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Sherlock, J. (Photographer). (2017 November 3). Here we observe a wild Jay Gittens (Project Director of Whale Shark Diaries) swimming with his favourite big fish [Digital Image]. Retrieved from https://www.facebook.com/

While ecotourism has the opportunity to benefit local peoples and raise awareness for conservation issues, concerns have been raised over the potential impacts on the behavioral ecology of whale sharks from repeated exposure to tourists (Cisneros-Montemayor, et al., 2013; Orams, 1996). Several anti-predatory, evasive behaviors have been observed while snorkeling and diving with whale sharks. When these sharks are pursued by divers, they can roll onto their sides, a behavior known as “banking” (Martin, 2007; Quiros, 2007). Whale sharks have the thickest skin on earth, nearly 14 cm thick along their backs, which is studded with enameloid placoid scales (Kemp, 1999). It is thought that whale sharks bank when harassed by divers in order to protect potentially sensitive underbellies (Quiros, 2007). These sharks have also been observed diving to the depths when harassed by divers (Martin, 2007).

Guy Skillen. (Videographer). (2013 July 20). Injured whale shark banking for protection [Video Clip]. Retrieved from https://www.youtube.com/

 

While I haven’t seen this first hand with whale sharks (yet!) I have experienced similar evasive behavior from other shark species. While snorkeling with leopard sharks (Triakis semifasciata) in La Jolla, California. These sharks are rather timid by nature, often avoiding diver interactions when they feel threatened. I witnessed several sharks take off with a sudden burst of speed when startled by a diver or the flash of a camera. Whale sharks also appear to be affected by the flash of a diver’s camera. They have been observed rolling their tiny eyes back when exposed to the flash (Martin, 2007).

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Flannery, A. (Photographer). (2016 September 8). Shy leopard shark in La Jolla, CA [Digital Image].

The effects of ecotourism on whale sharks goes beyond diver interactions. Whale sharks also encounter boats on a regular basis due to this booming industry. Recently boating traffic has increased in the Gulf of California, the number of observed boating related injuries have also increased. Nearly 70% of all whale sharks present with boating related injuries in the Gulf (Nelson & Eckert, 2007; Ramírez-Macías, Vázquez-Haikin, & Vázquez-Juárez, 2012). These negative interactions with boating traffic may disrupt mating behaviors, migration routes, and even access to important feeding grounds (Martin, 2007).

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de la Parra, R. (Photographer). (2010). Boat strike injury on a whale shark [Digital Image]. Retrieved from http://nationalgeographic.com/

At present, Mexico is looking to improve the whale shark ecotourism industry for the health and safety of sharks and humans a like. In 2003 a Code of Conduct was accepted by both the ecotourism industry and local government which formally incorporated the code of conduct into permits issued to tour operators (Rodríguez-Dowdell, Enríquez-Andrade, & Cárdenas-Torres, 2007). The code of conduct provides two sets of guidelines, one for divers and another for boat operators. The code states that divers are not to touch whale sharks, maintaining at least a 2 m distance from the shark’s head and 3 m from the tail. Tourist operations and boat operators must maintain a distance of 5 m from any shark, and only one boat at a time may approach a single shark. Divers and boat operators are not to restrict any natural movements or behaviors in any way (Cárdenas-Torres, Enríquez-Andrade, & Rodríguez-Dowdell, 2007).  Today, the code of conduct extends beyond Bahia de los Angeles as the industry standard throughout Baja California Sur.

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Swimming with Whale Sharks* (Figure 2. Cárdenas-Torres, Enríquez-Andrade, & Rodríguez-Dowdell, 2007) *Distances were increased following publication of this study to 2 m from the head and 3 m from the tail

 

In addition to the Code of Conduct, boating licenses have also been limited following a carrying capacity study to 83 licenses (J. Gittens, personal communication, November 13, 2017). In La Paz, owners and operators of whale shark ecotourism are required to attend a 4 day seminar featuring a boating practical on the last day. Project Director of Whale Shark Diaries, Jay Gittens, posted to his Facebook page about the seminar back in September:

19/September/2017:

SEMARNAT [Secretaría del Medio Ambiente y Recursos Naturales] training workshop for whale shark guides in La Paz, México is about to commence. This workshop provided by the Mexican Environment Agency Is now mandatory for all captains and guides that provide whale shark trips in La Paz Bay. It’s a 4 day course with day 4 being an in-water practical. This initiative will improve the protection for the whale sharks whilst also improving the quality of the services provided by operators.
Here’s to a sustainable whale shark tourism industry for La Paz, México.

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While the long-term effects of the ecotourism industry in the Gulf of California on whale shark population is unknown, locals and the government are making strides to improve industry practices for a more positive experience for tourists and sharks alike. Through the exposure to these incredible animals, tourists are made aware of the need for conservation of the region and the endangered whale sharks. Locals in multiple industries benefit from the boom in tourism. However, the significant number of individuals presenting with boat strike injuries suggests there is still room for improvement before the ecotourism industry lives up to the IUCN standard.

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Flannery, A. (2017). Whale Shark in La Paz Bay [Digital Image]. Original Content.

The new Ocean For Sharks Shop is open! There’s handmade ocean inspired plush animals, canvas paintings, and of course my children’s book, Winifred the Wondrous Whale Shark, available in print and PDF. Be sure to stop by. Remember proceeds benefit shark research and conservation with a donation to Project AWARE!

Remember you can make a difference for marine ecosystems by calling your Congress man or woman and tell them that you care about the quality of our waters! Sharks, rays, and other marine organisms cannot speak or be represented in Congress. They need your voice. Get involved and stand up for sharks. Until next time finatics.

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Featured Image Source

Murch, A. (Photographer). (n.d.). Whale Shark in the Sea of Cortez [Digital Image]. Retrieved from http://bigfishexpeditions.com/

Literature Cited

Cárdenas-Torres, N., Enríquez-Andrade, R., & Rodríguez-Dowdell, N. (2007). Community-based management through ecotourism in Bahia de los Angeles, Mexico. Fisheries Research, 84(1), 114–118.

Duffy, C. A. J. (2002). Distribution, seasonality, lengths, and feeding behaviour of whale sharks (Rhincodon typus) observed in New Zealand waters. New Zealand Journal of Marine and Freshwater Research, 36(April), 565–570.

Eckert, S. A., & Stewart, B. S. (2001). Telemetry and satellite tracking of whale sharks, Rhincodon typus, in the Sea of Cortez, and the north Pacific Ocean. Environmental Biology of Fishes, 60, 299–308.

Kemp, N. E. (1999). Integumentary system and teeth. In Sharks, Skates, and Rays. The Biology of Elasmobranch Fishes (pp. 43–68).

Lluch-Cota, S. E., Aragón-Noriega, E. A., Arreguín-Sánchez, F., Aurioles-Gamboa, D., Jesús Bautista-Romero, J., Brusca, R. C., … Sierra-Beltrán, A. P. (2007). The Gulf of California: Review of ecosystem status and sustainability challenges. Progress in Oceanography, 73(1), 1–26.

Martin, R. A. (2007). A review of behavioural ecology of whale sharks (Rhincodon typus). Fisheries Research, 84(1), 10–16.

Pierce, S. J., & Norman, B. (2016). Rhincodon typus. The IUCN Red List of Threatened Species 2016.

Quiros, A. L. (2007). Tourist compliance to a Code of Conduct and the resulting effects on whale shark (Rhincodon typus) behavior in Donsol, Philippines. Fisheries Research, 84(1), 102–108.

Ramírez-Macías, D., Vázquez-Haikin, A., & Vázquez-Juárez, R. (2012). Whale shark Rhincodon typus populations along the west coast of the Gulf of California and implications for management. Endangered Species Research, 18(2), 115–128.

Wilson, S. G., Taylor, J. G., & Pearce, A. F. (2001). The seasonal aggregation of whale sharks at Ningaloo Reef, Western Australia: Currents, migrations and the El Niño/ Southern Oscillation. Environmental Biology of Fishes, 61(1), 1–11.

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5 thoughts on “A Whale Shark Tale: The Gulf of California

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  1. Good luck on your trip to study and swim with whale sharks! I have had the privilege of swimming with a whale shark before, and it is amazing. I am currently studying marine biology and ecology, and I am most interested in sharks, specifically whale sharks. How did you get involved studying whale sharks?
    And do you know of any internships that are accepting applicants to work with whale sharks?

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