Photo: Alistair Dove/Georgia Aquarium

The largest fish in the sea is a shark the size of a school bus, but it is not a fearsome toothy predator. Rather, the whale shark is a tranquil, filter-feeding giant, found throughout the tropical oceans of the world, where they feed on plankton and fish eggs. Until about 20 years ago scientists thought that whale sharks were solitary open ocean behemoths, but increasingly, we have learned of places around the world, about a dozen so far, where whale sharks gather reliably in substantial numbers and quite close to the coast. This has created blossoming ecotourism markets, ones based on creating opportunities for people to experience these spectacular and charismatic animals; but these experiences do not come without their downsides and this tremendous opportunity to foster connection with iconic marine species, has created some urgent problems as well.

In the Mexican state of Quintana Roo, the largest of all known whale shark gatherings has become the focus of intense ecotourism pressure. Ecotourism began as a cottage industry in the sleepy coastal resort village of Isla Holbox on the shores of the Gulf of Mexico during the 1990’s, but since 2006 the whale sharks have moved further to the east – scientists aren’t sure why – within a convenient daytrip distance of the much larger Caribbean tourist mecca of Cancun. This migration shift, combined with a better experience offered by the clearer blue waters in the new location, has led to an explosion in ecotourism activity. Boat operators based in Isla Mujeres, and increasingly Cancun, have radically expanded their fleets to provide trips for tourists to experience the marvel of the whale shark gathering, and intense competition has driven prices down to just $120-$170 dollars per person for this once-in-a-lifetime bucket-list experience. Tourists, primarily from the US and Europe, are unknowingly providing an economic incentive for unsustainable practices that threaten both the industry and the very whale sharks themselves.

The concerns that have grown alongside this lucrative new market have reached a precarious point. The number of boats licensed to visit the whales has grown from just a handful at Holbox, to over 250 in 2013 and 280 in 2014. This means that on many days, the boats outnumber the whale sharks, creating a literal traffic jam on the water and a risky cocktail of propellers, large animals and inexperienced snorkelers in an open water environment some 20 miles from shore. Indeed, a significant portion of the sharks now show signs of recent or past boat strike injury, the majority of which almost certainly result from unintended contact with ecotour boats.

Ultracompetitive ticket agents back on shore entice business with money-back guarantees of animal sightings, which provides incentive for boat captains to flagrantly disregard animal interaction guidelines in order to protect their already-razor-thin profit margins. These guidelines are voluntary and borrowed from the time when the animals gathered inside a marine protected area at Isla Holbox. The guidelines are also compulsory and enforced by CONANP, the protected areas agency of the Mexican government. It is therefore unclear which government agency is ultimately responsible for safely and effectively managing the aggregation at the new site, but while that question gets endlessly debated, the ecotourism fleet grows unabated.

Furthermore, the new location is adjacent to one of the busiest commercial shipping lanes in the world: the western entrance to the Gulf of Mexico. This year, for the first time, we witnessed a cargo ship forced to take evasive maneuvers to avoid collision with both the sharks and the ecotour fleet. Considering all of these developments together, a clear picture emerges of a disaster waiting to happen. Non-profit organizations like Georgia Aquarium, Ch’ooj Ajauil AC, Amigos de Isla Contoy AC and the Blue Realm Project are working to improve the situation, but more cooperative involvement from the Mexican government and the ecotourism industry is sorely needed.

The whale sharks of Quintana Roo are rapidly becoming another example of the all-too-frequent Tragedy of the Commons scenario, in which a group of individual stakeholders, in this case ecotourism boats, inevitably destroy a common resource, even when it is in their best individual long term interests not to do so. The biggest question is not now “Will this amazing ecotourism experience crash?”, but rather “Will it be us or them?” Will the whale sharks abandon their feeding site for bluer pastures, putting an end to one of nature’s most incredible gifts? Or will there be a human or animal (or both) tragedy that forces an extrinsic intervention in a situation that is currently hopelessly under-regulated? Either way, the status quo and foreseeable trajectory is simply unsustainable, and tourists planning to visit the whale sharks of the Yucatan should consider that before laying down their tourist dollar for an experience that is no longer ecotourism, so much as it is exploitative tourism on a massive scale.

Dr. Alistair Dove, is Director of Research and Conservation at Georgia Aquarium in Atlanta. He is a Scientific Advisor to Ch’ooj Ajauil AC (Cancun) and The Blue Realm Project (US), collaborative NGOs aiming to improve understanding and protection for marine life of northern Quintana Roo, Mexico