Ecuador, Isla de la Plata Manta study 2010
We had been contacted by Mark Harding, a British diving tour operator approximately 12 months ago. Mark had based himself at Puerto Lopez over the summer months for the past 5 years where he had been working as a guide and instructor. He had noticed that there seemed to be a large number of mantas sighted during the summer months (June to September) and had been researching the locations they visited and had started to identify individual mantas. He had contacted us to identify some of the behaviours he was observing. It was apparent from his photos and videos that the mantas were visiting cleaning stations.
The mantas seen here are the larger Manta birostris or giant manta species. Although we have seen a few in the Maldives, we had little experience of them so we decided to spend some time here to obtain some initial observations of this species and see if there was potential to develop a diving tour suitable for divers who would be interested in helping gather research on this species whilst enjoying an interesting holiday here.
The travel to Puerto Lopez is quite straightforward. We flew to Quito via Houston on Continental although there are other major airlines offering Quito and then made the 35 minutes internal flight to Manta next day. The transfer from Manta too a little over an hour and was an interesting drive through dry forest. We stayed at the Hosteria Mandala, which is probably the best hotel in town. It is simple and rustic with all the creature comforts necessary. The rooms are scattered throughout a beautiful flower garden which attracted tropical birds and were clean, with hot water and decorated with ingenious wood carvings. The entire property is scattered with interesting items of art created by the owner, Aurelio. We breakfasted there every day and had dinner there several nights as it was one of the best restaurants in town.
Puerto Lopez’ main industry is fishing and most of its 15,000 inhabitants live very simply. It is a seaside resort for Ecuadorians during the sunny months (January to March) and there were lots of backpackers and “eco-tourists” whist we were there, attracted by the seasonal humpback whale watching and rainforest trekking activities.
The manta diving was conducted at Isla de la Plata, located about 25km offshore. We met at the dive shop, carried our gear out to the beach to the boat, via the fishermen landing their daily catch and made the journey out to the island which took about 1 hour 10 minutes in good conditions. On the way Mark’s research team conducted a current direction experiment in mid water to the SE of the island. After registering at the Ranger’s station (Mark had arranged the only diving permit for the island, within the Machalillia marine park area) we would have a look around for any manta activity and make two dives. We mainly dived at “the wall” a series of pinnacles on the northern drop-off, and Punto del Faro and Roca Onda which are two small promontories. The sites were all pelagics cleaning stations, inhabited by barber butterflyfish (Johnrandallia nigrirostris) and king angelfish (Holocanthus passer). Other (mainly wrasse) cleaners were present but none were observed cleaning mantas.
On the best days we saw 12-15 different mantas arrive to a cleaning station during a 45-70 minute dive. If the mantas were present they were also seen just under the surface from the boat, and several were seen breaching but we did not observe feeding or any reproductive behaviour. The mantas came in very close and were very tolerant of divers particularly when we were in small groups and allowed us to get close up ventral and dorsal shots which are useful for investigating cleaning behaviour. This makes for a really exciting opportunity for divers as it allows for very close interactions with the mantas, compared to the rather static “observations” we make at cleaning stations in the Maldives. Once the mantas became accustomed to us we could swim underneath and on top of them and they seemed to tolerate us as part of the cleaning process. The photograph above shows Dr Csilla Ari photographing a manta's ventral surface in order to identify it.
Mark’s team took surface plankton trawls daily but it is important to note that the mantas were not feeding. We made exploratory visits to other areas and discovered a new cleaning station area which is important in confirming that mantas are visiting locations other than those already known. On the dives when we saw mantas, we were completely blown away by the size, curiosity and interactivity of this species. The cleaning stations around Isla de la Plata are, without doubt, extremely important sites (of world heritage status) for the study of this species. Diving tourism can be developed in this area but it must be properly managed to protect the sites. Mantas are not seen every day, as groups of mantas visit and move on, with the change in currents, but the phenomenon is not remotely understood yet. It may take several years before correlations in manta presence with tide, lunar cycle, current direction etc. are understood.
"Barber" butterflyfish cleaning dorsal surface of a giant manta.