Dolphin Research in the Port Honduras Marine Reserve

At nine o' clock in the morning, TIDE intern Jorge Rojas was already at sea combing the waves for a glimpse of a dorsal fin.

Port Honduras Marine Reserve

“When we see a dolphin, we just slow the speed of the boat and approach little by little, slowly,” Rojas said, “and then we take all the pictures we need.”

 

Rojas spent three months last summer with TIDE’s research and monitoring team researching pods of dolphins in Port Honduras Marine Reserve. Twice a week he left Abalone Caye in a fishing patrol boat with camera in hand, on a mission to establish baseline information on the presence of dolphins here.

 

The boat would come alongside the dolphins and Rojas would take photographs of their dorsal fins, on both sides if possible. They also counted the dolphins, taking note of the number of calves in the group.

 

Each dolphin has a distinct set of markings on its dorsal fin, so by photographing fins Rojas was able to identify individual dolphins in the reserve. Computer software digitally recognized photos and compared the newest dorsal fin photograph with the catalog of previously identified individuals. If the fin didn’t match any pictures in the catalog, the software created a new folder with the best photographs of the individual, a profile drawing of the dorsal fin and a map showing where it was sighted. This kind of photo identification helps determine whether dolphins are residents or visitors as well as information on the number of individuals, birth rate estimates, mortality, and migration.

 

Rojas was also the first researcher to plot his routes using a GPS. TIDE plans to implement this system on all their patrol boats in order to improve fishing patrol effectiveness.

Port Honduras Marine Reserve

  Port Honduras Marine ReserveOut of 18 trips into the reserve, Rojas saw dolphins 11 times. He observed two species of dolphins: a group of sixteen bottlenose dolphins and a larger group of about twenty-five spotted dolphins.

 

 “The bottlenose approached the boat, but not too much. We had to follow them to take all the pictures,” Rojas said. “The spotted dolphins were really curious! They were really friendly and actually swimming beside the boat. They were playing.”

 

Port Honduras Marine Reserve

Because the dolphins approached so closely, Rojas was able to observe the adult dolphins and calves interacting.

 

“With the spotted dolphins, the most curious were the calves. They were swimming just beside the boat,” Rojas said. “Sometimes the adult dolphins came to the group of calves and were calling them. Like [human] adults with little children, they were saying, ‘Come here, son! We have to go,’ and the kids were like, ‘No, I want to play!’ It was really cute.”

 

TIDE asked Rojas to gather information on dolphins because of Providence Energy’s proposal to conduct seismic and oil exploration in Port Honduras Marine Reserve, which could have a negative effect on the wildlife living there, including the critically endangered Goliath Grouper, endangered West Indian manatee and dolphins which frequent these sheltered food-rich waters. 

 

One cause of concern for dolphins in particular is the use of seismic testing. Oil companies send waves of sound through the surface of the water and the Earth’s crust to explore for petroleum deposits. Because dolphins use sonar to navigate and communicate, this can be extremely detrimental to their health. Seismic testing has been known to deafen dolphins; when they can no longer navigate, they wash up on shore in groups. 

 

“Just imagine being surrounded by a big noise you cannot escape from. Dolphins can actually be hurt by these big [sound] waves,” Rojas said. “That will be reflected in the population of dolphins within PHMR.”

 

Dolphins play a vital role in the ocean’s ecosystem as regulators of the fish population. “If a fundamental role in the food chain is broken, there will be chaos in the marine environment,” Rojas said.

 

 “Dolphins are not the only species at risk from the seismic plans”, says James Foley, Science Director at TIDE and project supervisor for Rojas. “The shallow, sheltered mangrove cayes and seagrass beds of the reserve are critical nursery habitat for many species of fish, including commercial species that support local livelihoods. The success of Managed Access, an innovative fisheries management scheme being implemented by the Belize Fisheries Department and TIDE in PHMR, is threatened by this proposal due to its potential catastrophic acoustic impacts on fish. Seismic testing could spell the end of critically endangered Goliath grouper nursery grounds, with local hydrology leading water and potentially oil and waste into the Payne’s Creek lagoon where they are known to reside in large numbers in their juvenile stage. The endangered West Indian manatee still thrives in this corner of the Caribbean. Bottlenose and spotted dolphins are drawn to PHMR by the abundant fish in the reserve. These rare and special animals, as well as the beautiful beaches of the Snake Cayes, draw many tourists to the reserve, supporting local tourism. Seismic shock waves have caused internal hemorrhaging and audial damage to such animals in other areas. Loss of these would devastate the very things that make PHMR unique and special, and destroy sustainable local livelihoods in fishing and tourism”.

 

One of the key findings of Rojas’ study was that some areas of the PHMR have higher concentrations of dolphins than others. The area of the Payne’s Creek Lagoon near Deep River and Punta Ycacos are hot spots for dolphin sighting. Providence Energy is proposing to conduct aerial and seismic surveys that would traverse both these areas.  

 

 

[Source of Aeromagnetic Survey Lines: Department of the Environment, Government of Belize]dolphin-sightings-&-aeromagnetic-survey-lines_0.jpg

As shown in the map that highlights aeromagnetic survey lines and areas frequented by documented dolphin pods, a significant intersection of the two takes place within the Punta Ycacos lagoon, Deep River, TIDE Private Protected Lands and Port Honduras Marine Reserve. The seismic lines (which are not shown in this map) also follow very similar routes. This is very bad news for not only dolphins, but also manatees, goliath groupers and many other important species and habitats in this area.

 

Rojas believes there are others ways to make money using the abundant resources of the Port of Honduras Marine Reserve for eco-tourism. “It will be interesting to do research on the economic importance of dolphins [in terms of] dolphin observation.” Rojas said. “Everybody loves dolphins. Eco-tourism could be an interesting development in PG and in all Belize. That is already happening.”

 

Rojas has first-hand experience with the magic of being up close and personal with dolphins. 
 “There are so many mysteries around the dolphins,” Rojas said. “[Being close to them], wow. It was amazing.”

 

 

Written by: Amanda Munro, TIDE Intern

Date: June 10, 2014 Author: kmahung
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