Solveig and her boyfriend Lasse, both from Denmark, visited Coco Beach this week for a nine days vacation. They are both hunters and love skiing, but only Lasse was a certified diver, so Solveig was a bit interested in diving but also afraid it would take to much time of their vacation. Finally she jumped in the pool with Thomas to make a free pool-trial and she got hooked. Within 4 days she finished her PADI Open Water Diver certification and she still didn’t had enough, so she decided to also take the PADI Advanced Open Water Diver course right away.

Rex, Solveigs instructor, handing over the Advanced diploma after 2 successful courses with him.
Now, 7 days later she is the proud owner of 2 certifications and is planning to come back to take her Rescue Diver course and Nitrox course. Congratulations Solveig and we are all looking forward to see you both again.
Bottlenose dolphins
This is a small warm-up for next weeks newsletter because Ino, Rex and Thomas are attending a 2 days course how to handle stranded mammals. During the course they will be handling life mammals like bottlenose dolphins and a false killer whale. But much more about that in the next newsletter.
Bottlenose dolphins are the most common and well-known members of the family Delphinidae, the family of oceanic dolphins. They inhabit warm and temperate seas worldwide. And these dolphins are also the ones sighted when you join a dolphin watching trip from Coco Beach or when you are crossing over from Batangas to Coco Beach.

A bottlenose dolphin chasing the outrigger from the Coco Beach boat.
Bottlenose dolphins live in groups typically of 10-30 members, called pods, but group size varies from single individuals up to more than 1,000. Their diet consists mainly of small fish, crustaceans, and squid. Although this varies by location, many populations also share an appetite for fish from the tuna and mackerel family.
Dolphins often work as a team to harvest schools of fish, but they also hunt individually. Dolphins search for prey primarily using echolocation, which is similar to sonar. They emit clicking sounds and listen for the return echo to determine the location and shape of nearby items, including potential prey. Bottlenose dolphins also use sound for communication, including squeaks and whistles emitted from the blowhole and sounds emitted through body language, such as leaping from the water and slapping their tails on the water surface.

Two bottlenose dolphins playing around in the surface.
Bottlenose dolphins are popular from aquarium shows and television programs such as Flipper. They have also been trained by militaries to locate sea mines or detect and mark enemy divers. In some areas they cooperate with local fishermen by driving fish into their nets and eating the fish that escape. Some encounters with humans are harmful to the dolphins: people hunt them for food, and dolphins are killed inadvertently as a by-catch of tuna fishing.
They are gray, varying from dark gray at the top near the dorsal fin to very light gray and almost white at the underside. This counter shading makes it hard to see, both from above and below, when swimming. Adults range in length between 2 and 4 meters, and in weight between 150 and 650 kg. Males are on average slightly longer and considerably heavier than females. In most parts of the world the adult's length is about 2.5 meters with weight ranges between 200 and 300 kg and can live for more than 40 years.

A dolphin mother with her calve.
The dolphin's search for food is aided by a form of sonar known as echolocation: they locate objects by producing sounds and listening for the echo. A broadband burst pulse of clicking sounds is emitted in a focused beam in front of the dolphin. To hear the returning echo they have two small ear openings behind the eyes, but most sound waves are transmitted to the inner ear through the lower jaw. As the object of interest is approached the echo grows louder, and the dolphins adjust by decreasing the intensity of the emitted sounds.
Some large shark species, such as the tiger shark, dusky shark, great white shark and the bull shark prey on the bottlenose dolphin, especially calves. The bottlenose dolphin is capable of defending itself by charging the predator: dolphin 'mobbing' behavior of sharks can occasionally prove fatal for the shark. Targeting a single adult dolphin can be dangerous for a shark of similar size. Certain (but not all) killer whale (orca) populations may also prey on dolphins, but this seems rare. And other orcas again may swim with dolphins.
Swimming in pods allows dolphins to better defend themselves against predators. Bottlenose dolphins either use complex evasive strategies to out swim their predators or mobbing techniques to batter the predator to death or force it to flee. |