,

Coiba’s little ones – Part 2

Spotted sharpnose puffer

Adorning its dark-brown body are countless white dots, which grow to become more numerous in the adults. In fact, the scientific name (Canthigaster punctatissiam) quite literally translates as meaning covered in small spots. They tend to spend much of their day gingerly swimming around, ducking in and out of caves and crevices in their surroundings. They are generally solitary, but occasional form loose groups in which it seems sometimes that they are playfully chasing each other. What I love about them? Apart from their cute appearance with their pointed snout and how they are frantically waving their little fins to propel themselves forward they seem to be quite curious and unafraid. This reaction to a diver while they self just grow to a maximum of 4 inches is quite awe-inspiring.

-by Inga

/by
,

Coiba’s little ones – Part 1

Tufted tube blenny

You can spot this little friend at the rocks where it will look out of the mollusk and worm tubes which they inhabit. You will nearly never see one of them outside so it’s hard to imagine that they actually have a quite elongate body with up to 8 cm. They just come out occasionally to nab floating particles of Zooplankton. Normally you can  observe them extending their heads out of the tubes. On one rock you will probably see many of them even if they are solitary living fishs. Well, but who would like to share these little tubes? The reason why they are one of my little favorites is the tuft of densely packed hair like structures between their huge eyes.

by Inga

 

/by
, ,

Sea turtles – our fabled friends

Sea turtles are probably one of the most well-known and beloved creatures of our vast oceans. Whilst they do breathe air, they can stay under water for around 40 minutes – or even up to several hours while they are asleep. As Reptiles, Turtles lay eggs. The females usually return to the beach where they were born. On the beach, they dig hole in which they lay up to 300 eggs and then cover them up with sand and finally they camouflage them. This is the only protection those eggs will have, the mother returns back to the ocean right after laying her eggs. Those little guys unfortunately have very little chance of making it to adulthood. A lot of them will get eaten or won’t even make it to the ocean safely after hatching. But even if they do, more danger in form of predators awaits in the ocean. Luckily, enough make it so that we can observe them on almost every dive.

They have fascinated humans for several thousand years and appear in mythology and cultural depictions throughout all cultures. Usually, they symbolize wisdom, patience and a certain easy-going way of life as they can live to over a hundred years old with the exact life span depending on the species of sea turtle. In Africa the story goes that turtles are the cleverest of all animals and they gave the other creatures their colours. In Nigeria the turtle is known as a trickster and accomplishes heroic deeds through various different stories. Meanwhile in ancient Greek and Roman mythology the turtle symbolized fertility and was thus an attribute of the goddess Aphrodite/Venus. In Tahitian culture the sea turtle is the shadow of the gods and the lord of the ocean.

Often they are connected with creation myths: There are stories in which the turtle literally carries the world on its back; in some stories that turtle stands on the back of another larger turtle – it is “turtles all the way down”. In other stories our planet is carried by four elephants who stand on the back of a turtle. Unfortunately, in a metaphorical way, turtles really are carrying some of the weight of the world as they are one of the creatures impacted the most by climate change. The reason for this is that the gender of the little sea turtles hatching from their eggs on the beach is determined by the sand temperature. As a result, rising temperatures have led to a too high percentage of female sea turtles, in some areas it is as high as 95%. This makes reproduction even harder, and it is already not easy for our beloved creatures. Sea turtles take decades to reach sexual maturity. When they do return to the beach to lay their eggs the survival rates are unfortunately very low.

Sea turtles are not just the cute, calm creatures we love so much on our dives though – they have a real significance to the ecosystem. For instance, they eat the seagrass, keeping it short enough so it keeps spreading over the ocean floor providing an important habitat for lots of other species who find shelter and food in these grassy beds. They also eat jellyfish. The leatherback turtle is immune to the poison of the box jellyfish and hence controls its population keeping beaches safe for us humans as well.
In Coiba National Park one of the spots where we are most likely to find sea turtles is at the so-called cleaning stations that exist at certain dive sites, like Iglesia. At these cleaning stations fish eat the parasites inhabiting the sea turtles among other bigger animals like rays making it a mutually beneficial institution: they feed on the parasites and the sea turtles and rays get rid of those nasty little plagues. It is fascinating to observe such areas where the animals knowingly go to get cleaned off, and it is what makes Iglesia one of my favorite dive sites.

 

-Text and video by Saskia

/by
, , ,

Underwater fairytale

Sometimes, really just sometimes, you get one of those days in Coiba that are like dreams coming true. Last week one of our groups had such a day. The weather was beautiful, which is unusual this time of the year, and the boat ride out to the national park was already stunning.

The first dive site we visited was el Bajo Piñon. Full of life there were lots of schools of fish as well as turtles and our current favourites here – manta rays. It was astonishing to see this dive site bursting with life in all its colours. After a surface interval on one of the little beaches, where the sea shells made a sound like little bells getting tossed against each other in the waves, we headed to our second dive site – Faro. There, the surface current was extremely strong so that it was a struggle to get to the descent line. However, our dive instructor Kim reminded us that strong currents often mean lots of life and she couldn’t have been more right. After the group managed to descend and drift dive for a bit we started hearing very high pitched clicking noises and whistles – coming from hunting dolphins. Not long after we saw a school of bigeye jacks, fish dolphins like to hunt. And finally, they appeared. A group of three dolphins – a big one, a middle one and a baby dolphin- showed up and chased the fish making it look like a game. These creatures seem so intelligent, curious and alert. Every move they make is elegant and playful at the same time. It looked like the bigger dolphins were trying to teach the baby one how to hunt with the baby dolphin always being on the fins of the bigger one. They move incredibly fast in the water and soon enough this group disappeared again. Every now and then over the next couple of minutes we heard a high pitched whistle again until it got louder and more continuous and another pair of dolphins appeared, again shortly after we found a school of bigeye jacks. They hung around for a while longer, showing their teeth and fish inside their mouth making it seem like they were grinning at us letting us know how much fun they were having cruising through the water. It was an absolutely remarkable moment to observe those dolphins hunting and for me it was a childhood dream coming true. We rarely have the luck to see dolphins in Coiba, from the boats we see them quite often but mostly we just hear them on a dive without being lucky enough to spot them.

However, after this encounter our luck was still not used up. Shortly after the dolphins swam off we discovered a whale shark although whale sharks are mostly just observed during dry season here. We followed it and got up close only few meters away from the giant creature with its beautiful painting. Then it turned around and swam towards the group so everyone in the group saw it up close. We then said goodbye to the whaleshark as we had to go up for our safety stop. Without any surprise everyone went nuts once on the surface, talking screaming and laughing in excitement and joy. A lot of the divers had not done a lot of dives yet, but it does not take an experienced diver to realize how extraordinary this day had been. After a lunch break we then did a negative entry to our third and last dive of the day and again we had surprise visitors. A rare black tip reef shark and another manta ray came to say hi and swam past the group. Finally, we made our way back to the dive center with still a blue sky and memories for a life time. Even the instructor said it was one of her best days diving with 1000+ dives all over the world. Thank you Coiba for showing us all your beauty!!

– by Saskia

/by
, , ,

Manta Rays – Giants of the Sea

Here in Coiba we just can not get enough of rays hanging out with us on our dives with their movements so elegant it often seems like they are flying through water. Lately we have been particularly lucky and seen Mantas on most of our dives – sometimes just for a brief moment but more often than not they hang around for a bit or appear multiple times throughout a dive with every encounter unique in its own way.

Their colouring in particular on their belly is unique to every individual and allows to identify them.

The name manta originates from the Spanish and Portuguese word “manta” which means blanket or cloak and doesn’t refer to their colouring as one might think but instead to the way they used to be catched. They are mostly found in tropical and subtropical waters making Coiba National Park a perfect place to look for them.

Sometimes you will spot a fish seemingly attached to the manta near its head catching a ride and gaining some extra protection by its giant host. Those fish are called remora or are commonly also referred to as suckerfish as they quite literally suck onto their host. They do not have any negative impact on the ray in doing so, instead this is a special sort of symbiosis and exciting to observe as a diver and sometimes those little guys have been observed to even attach themselves to a diver.

Those giants reaching a fin span of up to nine meters do not just seem curious and smart – their brains are ten times larger than those of whale sharks and studies conducted in 2016 suggest they might even be able to recognize themselves in a mirror, a sign of self-awareness that is usually just observed in dolphins and certain species of monkeys. So, in a lot of ways those little geniuses like to outperform other members of their class with particularly skills in problem solving and communicating.

Some of our divers experienced that first hand when a manta ray entangled in plastic approached them. As the group was just getting ready for the safety stop the manta showed up swimming towards the group seemingly looking for help. After a bit of hesitation and back and forth it slowed down swimming at the same speed as the group as if it was realizing it is getting help now and let the dive instructor cut the plastic line it was entangled in. It stayed for a bit before the group surfaced and then swam away enjoying its freedom once more.

This is encounter adds to the stories that are out there about manta rays and dolphins who found themselves entangled approaching divers for help. It impressively illustrates how smart and communicative these creatures are but once more is a reminder of how important it is to keep our oceans clean and especially avoid plastic and plastic bags.

  • By Saskia, Photocredit: Katie and Kat

Sources: https://www.floridamuseum.ufl.edu/fish/discover/species-profiles/manta-birostris
https://oceana.org/blog/manta-ray-brainpower-blows-other-fish-out-water-10
https://divezone.net/manta-ray

/by
, , ,

This year‘s Whaleshark encounters

With the beginning of the rainy season not only the summer in Panama but also one of the most beautiful seasons for diving in Coiba comes to an end: The whale shark season.

This year, from january until the end of march, we were very lucky to experience many incredible encounters with these enormous and breathtaking creatures, who join us in the waters of the national park every year in search for plankton.

What we do know about whalesharks is unfortunately very little compared to what we don’t know about them. They can reach up to 15 meters in length and can weigh more than 10 tons, which is why they are the biggest fish in the world. They are  gentle creatures, living in water temperatures between 20 and 25 °Celsius, moving slowly and most of the time in shallow waters, which is why they are sadly very often a target of boat propellers or fishing nets.

While the world of science has always thought they were big migrators, travelling miles and miles through our oceans to mate, feed and to give birth, a tracking system by Conservation International has shown that for example the whalesharks around Indonesia rather do periodical „short roadtrips“ in different directions before they return to homewaters. We might never know for sure, but as long as they keep visiting us here in Coiba and enlight our dives with their magnificent presence, we can live with that.

Here are just a few captured moments with whale sharks in the Coiba National Park:

 

 

This one we saw in Cativo on the surface, so close!

 

Our instructor Kim enjoying the view! What a magical moment! Thanks Liz for the beautiful photos

 

The biggest fish in the ocean…

 

…feeding on plankton

 

And here some of our videos:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

/by
, ,

Jumping Mobulas: one of the deepest divers in our ocean

Diving with PDC always starts with a lovely one-hour boat ride to reach Coiba National Park. Most people hope for dolphins on the surface since they bring an unexpected joy to the boat ride. But the amount of plankton in the water makes it more common to see another beautiful creature jump out of the water: the Mobula ray (also known as devil ray). They can jump up to six feet, twist, turn and either land flat on their belly or go in smooth as they came out of the water. Scientists are not sure why these rays perform incredible surface acrobatics, but research suggests that these high jumps are related to their way of communicating, courtship rituals, escaping from predators and  the removal of parasites.

When diving in Coiba it’s quite common to see these beautiful Mobulas almost fly through the ocean. These great swimmers and jumpers move their fins up and down to steer through the water. Sometimes you see one or a couple performing a little show but if you’re really lucky you can see big schools of 100+ Mobulas passing by while you’re diving or during your safety-stop. Especially while feeding, eating plankton and tiny fish, Mobulas group together. It’s incredible how they can create a dark cloud of movement in the ocean. It’s very rare to see these big schools of Mobulas passing by while diving, so we’re very lucky to have them as regular visitors in Coiba.

Most people think that Mobulas live just below the surface in warm temperatures. But recent findings revealed that these rays can descend with speeds of 22 km/hour (which is way faster than sharks and whales descend) to depths of nearly 2 km! These deep dives take them 60-90 minutes and brings them to waters of only 4 degrees Celsius. To prepare for their deep and icy dives they play in shallower water where it’s warm to heat up their network of blood vessels in the brain to make sure their brain keeps active during their deep and icy dive. This makes them not only one of the best acrobats but also some of the deepest and fastest divers in the ocean.

 

-by Cece

 

Sources:

http://www.bbc.com/news/science-environment-28087489

http://www2.padi.com/blog/2015/10/31/9-facts-about-devil-rays/

https://kids.nationalgeographic.com/animals/mobula-ray/#mobula-jump.jpg

 

Photos:

Christopher Swann, Sabina Schreck

 

/by
,

Octopuses: The Masters of Camouflage

In Coiba National Park, we are sometimes lucky enough to observe the incredible octopus, charismatic creatures known for their intelligence and their mastery of camouflage.  If you haven’t seen it yet, this popular video from a TED talk is one you can’t miss that shows how phenomenal the octopus’s ability to blend in with its surroundings can truly be: https://www.youtube.com/watch?v=PmDTtkZlMwM.  Octopuses are sometimes called the chameleons of the sea due to this amazing skill.  It is well known that these animals can change their color at the blink of an eye to blend in with their surroundings, creating varied patterns and undulating displays.  But not only can they change their skin color and pattern, they are also able to alter the very texture of their skin to better match their environment.  One species of octopus even changes its arm shape and swimming behavior to mimic other marine species that are venomous, or that prey upon the species threatening it.  So, how do they accomplish these incredible physiological feats?

Skin Color and Pattern

The skin of many cephalopods (octopuses, squid, and cuttlefish) is lined with thousands of specialized pigment cells called chromatophores.  Each chromatophore contains a tiny balloon-like sac of pigment of a different color.  By controlling the size of these cells through muscle contractions, octopuses are able to alter the color of their skin rapidly. This is much like if you squeezed a dye-filled balloon- the dye would be pushed to the top and the surface of the balloon would stretch, making the color of the dye appear brighter.  In the same way, using muscle contractions an octopus can expand and contract various chromatophores in its skin to make different colors more apparent, creating the patterns it desires on its skin to communicate with other octopuses or to blend in with the surrounding environment.  They can produce a variety of colors and even rapidly changing undulating color displays, and these color changes can occur within milliseconds.The pigments of octopus chromatophores are usually red, yellow, or brown, so sometimes octopuses must match colors in their environment that they cannot produce with mixes of these pigment colors. This is when iridophores, another type of cell in their skin, come into play.  Iridophores reflect red or blue light based on the angle of the cells.  By controlling the angle of iridophores and combining this effect with that the right chromatophore patterns, octopuses can create a phenomenal copy of the seafloor or surroundings they wish to blend in with.

Skin Texture

Not only can octopuses change their skin color, but they can also alter the texture of their skin, making themselves appear smooth or bumpy to various degrees.  They do this by changing the size of projections on their skin called papillae, using specialized muscles to make their skin appear a range of textures from smooth to bumpy to covered in pointed spikes.  By doing this, an octopus hiding amongst coral can not only match the color of the coral, but can also give itself a texture matching the coral as well, eliminating the lines where the edge of its body ends and the coral begins completely.  They can then re-smooth their skin to reduce drag when swimming and allow for a quick escape from pedators.

Mimicry 

There is one species of octopus, appropriately named the Mimic Octopus (Thaumoctopus mimicus), that not only changes its color and texture but also changes the way it swims and moves its arms when threatened to mimic other toxic marine organisms in order to frighten away its predator or make itself appear less appetizing.  It can impersonate 15 different species that we know of!  The mimic octopus has been observed gliding over the seafloor with its arms pulled inward and its entire body flattened like a leaf to mimic a flatfish, crawling into a burrow and leaving two of its arms out on the seafloor with a black and white pattern on them to look like a sea snake, and spreading its arms out and propelling itself through the water to imitate a lionfish.  Mimic octopuses in different regions or habitats differ in which species they most frequently mimic based on which predators are found in that area.  For instance, those in areas with abundant lionfish more often take on a lionfish-like form.  They also choose to imitate different animals based on what organism is threatening them- when threatened by damselfish, they are observed imitating sea snakes, a common predator of the damselfish.  The fact that the species it resembles are all venomous or toxic combined with the differences in mimic octopus behavior when presented with different threats in different regions provides evidence that this is a deliberate mimicry of other species.  Check out this video to see some of this octopus’s amazing mimicry behaviors: https://www.youtube.com/watch?v=t-LTWFnGmeg!

 

-By Daryll

/by
,

Moray Eels & Groupers: Teamwork in the Marine Environment

In Coiba National Park, we have the pleasure of observing several species of moray eel, an incredible hunter with a flexible body to move between rocks and wait in crevices for passing prey, a keen sense of smell, and not just one but two sets of jaws. While most fish avoid these clever predators, Groupers are known to actually seek them out, coordinating a team effort to hunt alongside them and share the catch.

Groupers themselves are expert hunters as well, with bursts of speed that make them formidable opponents. However, with their larger size and bulky shape, they are not able to catch prey that hide in small spaces and cracks. So, when their prey is not easy to reach, they seek out moray eels to flush them out instead.

First observed in 2006, this partnership has been studied by many scientists around the world. In the open ocean, Groupers are observed doing a sort of shimmying dance underwater to summon moray eels and signal their desire to hunt in a team. Occasionally, they even point out the hidden prey to a nearby eel by doing an underwater headstand, pointing out the fish’s hiding spot with their head and shimmying their body (check out this link to see a video of this behavior). This behavior is only done when there is a moray nearby, and is stopped as soon as an eel arrives. More rarely, when an eel ignores the signal, some have even witnessed Groupers fearlessly approaching the moray and attempting to push it toward the target prey.

Upon seeing the signal, the moray responds by chasing the fish out of its hiding spot to be captured in the speedy Grouper’s jaws. The two then actually share the meal, enjoying the rewards of their complimentary hunting strategies.

This sort of cooperation is one of a few examples of different fish species teaming up underwater to hunt, and there are many other manners in which marine organisms partner up for the mutual benefit of both parties. This sort of teamwork between the ocean’s many species goes to show how truly dynamic and complex life underwater can be, and how lucky we are to be witnessing some of this diversity here in Coiba National Park!

-By Daryll Carlson

Want to know more? Here you’ll find a great article with everything you need to know about eels!

/by
, ,

Rainy Season Visitors – Part 2

Humpback whales are easily recognized because of their enormous size, their majestic whale songs and their stunning aerial acrobatics, often breaching the water despite their large bodies and landing with a tremendous splash. A fully grown humpback whale weighs more than 5 adult elephants and measures up to almost 20 meters in length, the size of a big bus. Humpbacks possess a massive tail fin called fluke and unusually long pectoral fins (1/3 the length of their body!), which they use for navigation through the world’s oceans. The only known predator of such huge animal is a pack of very hungry killer whales.

Humpbacks have a very diverse diet consisting of krill, plankton and small fish such as salmon, herring and mackerel. Humpbacks do not have teeth but baleen plates, with bristles attached to them that prevent small prey from escaping but allow water to easily pass through. Since they don’t have teeth they have to swallow their preys entirely. The way they hunt is a real spectacle. They use a technique known as bubble net fishing. This involves a group of humpback whales swimming around their prey in a circle, blowing bubbles around their prey in order to herd the fish into a tight ball and creating  loud vocal sounds to scare the fish to the surface of the water. Then, the humpbacks slap their fins against the water to stun the fish and immobilize them. Finally, the whales will swim up with an open mouth and engulf thousands of small fish in just a single gulp, using their baleen bristles to separate water and debris from prey and their tongue to push the water out of the mouth and to swallow their prey.

Humpback whales feed mostly during the summer feeding season, building up blubber (fat) reserves that they will use during their migration and mating season. They make huge annual migrations from summer feeding grounds near the poles such as Alaska and Antarctica, where they enjoy cold nutrient-rich waters, to warmer winter breeding waters near the Equator where they mate and bear offspring. This means that the visiting humpback whales that we can see in Coiba have travelled thousands of miles all the way from Antarctica, making this the farthest migration of any mammal! Moreover, during this long migration and their time in Coiba, they will be fasting, hardly feeding and living primarily off of the blubber reserves acquired during the feeding season! Their time in Coiba is mating season so here they either breed or, in the case of pregnant females, they give birth. Females produce a single offspring once every 2-3 years. The average gestation period is 11-12 months. This means that a female humpback in Coiba will get pregnant one year and then migrate back to the South Pole while pregnant. Once there it will be feeding for a few months and will then migrate thousands of miles still pregnant and fasting  back to the safer warm waters of Coiba, to give birth to her only calf! The mother will nurse the calf for about a year, with calves drinking up to 600 L of her mother’ s milk in just one day! A calf will continue growing until approximately the age of 10, when they reach full adult maturity.

A humpback’s song is beautiful, unique and can last for a long time. Imagine that you are underwater and all of a sudden you start to hear a very complex and loud mixture of low-pitched moans, whines and howls. You look around trying to find the source. The sound wraps around you but you cannot see where it comes from, and you know this orchestra is the work of one of these huge fellows which is perhaps a few miles away from you, since their magical songs can travel for great distances through the ocean. Can you imagine it? Believe me, it is a truly unforgettable experience. And it is even more amazing given the fact that humpbacks do not have vocal cords and are unable to breath through their mouth, so all their sounds are produced by pushing air out of their blowhole. The songs are still surrounded by mystery. We still don’t understand the impressive humpback’s ability to produce songs of such complexity, and we are not certain of the purposes behind them. Typically one population of male humpback whales will sing a variation of the same song. Because whale songs are sung exclusively by males, it is believed that the song could be a mechanism for mating used by males to show off their vocal abilities and appeal to females. If this is correct and you have the chance to hear a whale song, think you are listening to one of the most complex acoustic mating rituals in the animal kingdom. However, female humpbacks have very rarely been recorded approaching a singing male whale and male humpbacks do not exclusively sing during mating season. Therefore, some scientists believe that there has to be another purpose behind their songs. Perhaps songs act as synchronizing symphonies guiding the migration of groups of whales. We simply don’t know.

At one point these amazing creatures were considered highly endangered due to excessive hunting and commercial whaling. Since then they have made a huge comeback thanks to protecting laws and a general increase in environmental awareness among the public. Most populations today  and are no longer considered a concern from a conservation standpoint. However, they still face a number of threats from humans such as entanglement in fishing gear, harassment by whale watchers, boat collisions, overfishing that compromises their feeding grounds, and water and noise pollution as well as other environmental impacts on their habitat. Entanglement in fishing gear and other marine debris is known to occur during long migrations. Shipping channels and coastal developments may displace whales, discouraging them from breeding in an area that they would normally use. The population migrating in Central America is among the populations still at risk. Do not be discouraged, a lot is being done to improve their situation. I only ask you, if you want to see whales, wherever that may be, make sure you look for responsible operations that follow adequate guidelines for whale watching.

-By Rodrigo Villarino

/by