Thursday, 23 July 2015

More Gentle Giants in Mexico

Over 11 years after a trip to the Baja Peninsular where I had close encounters with friendly grey whales, I returned to the other side of Mexico in search of another group of gentle giants - the whale sharks that arrive here each year in May to feast on huge concentrations of tuna eggs. In the past, hundreds of whale sharks used to aggregate in the waters around Isla Holbox to the north of the Yucatán Peninsular, but then the tuna spawning must have moved south around the coast and Isla Mujeres and Isla Contoy are currently the best bases from which to see the sharks.

We flew into Cancún and because some of the people in our group weren't arriving until well into the evening we had a night in a huge, all-inclusive hotel outside the city and close to the terminal for the Isla Mujeres ferry. Although the hotel was busy, it wasn't devoid of wildlife and on my way back from breakfast the next morning I spotted an iguana (which later turned out to be a common black or spiny-tailed iguana). After carefully stalking the creature for a few minutes to get a photo, I realised that it lived right next to the children's swimming pool and therefore wasn't the slightest bit bothered about people.

Later that day, we travelled across to Isla Mujeres on the ferry, arriving on the last day of the annual whale shark festival - the people of the island are clearly proud of 'their' whale sharks.

We settled into our hotel, the gardens of which were home to a couple of dozen more iguanas, and we were treated to a lovely sunset before dinner.

Over the next few days, I went out on four boat trips with researchers from the Marine Megafauna Foundation and Mexican NGO Ch’ooj Ajauil AC and had amazing encounters with the whale sharks. The animals grow to 12 metres in length (although there are several anecdotal reports of individuals as large as 18 metres) but they attain that enormous size purely through filter-feeding, cruising steadily with their massive mouths open wide through clouds of fish eggs, tiny crustaceans such as krill and copepods, and other plankton.

Despite being such enormous creatures, whale sharks are elusive and much of their life cycle is still a mystery – for example the largest individuals, especially the mature females, are rarely encountered. The largest animals we saw in Mexico were ‘only’ about 9 metres long, but even the smaller individuals (which looked rather tubby and cute) were still 5 metres long – 3 times my height!

I did attempt to take some underwater photos of the whale sharks with my compact camera in a waterproof bag, but the results were not great so I decided to just enjoy the swims and took surface shots of the sharks from the boat instead. Here's my best underwater effort.

Ch’ooj Ajauil AC conducted the whale shark watching in a responsible manner and I had many prolonged swims alongside these beautiful ocean giants - often having the shark all to myself - without ever feeling that we were disturbing their vital feeding behaviour.
However the same sadly couldn’t be said for the activities of many of the other boat operators, and I hope that the research supported by our trip will enable Ch’ooj Ajauil AC to secure more effective regulation of the whale shark boat trips around Cancún.

As well as the whale sharks, we had some close encounters with giant manta rays, spotted a few bottlenose dolphins, and took a night time walk to a beach where green turtles were laboriously hauling themselves overland to dig a nest. Unfortunately we didn’t see any actual egg-laying, but we did get stopped and questioned by some police officers who were evidently either bored or didn't have the imagination to understand why someone would want to watch turtles.

Back at the hotel on our last day I took some final pictures of the resident iguanas and said farewell to Isla Mujeres and its amazing wildlife. I’m already thinking about where else I can go to see whale sharks again!