The Sea Around Us

Over the past few weeks, we’ve had the pleasure of encountering these playful and charismatic dolphins all around us. Often, we’ve seen them in large groups, feeding together and accompanied by opportunistic sea lions eager to grab a few leftovers. They’re among our most frequent visitors, sometimes appearing as small family groups, and other times delighting us with the sight of large pods cruising through the water.

Bottlenose dolphins are odontocetes, or toothed whales, meaning they have teeth unlike mysticetes, the baleen-bearing group of whales. They are among the most extensively studied marine mammals in the wild. Their presence in aquarium shows and the fame of the TV character Flipper have made them the most widely recognized dolphin species.

Typically gray in color, bottlenose dolphins get their name from their short, thick snout (or rostrum). Their bellies are lighter gray, almost white, while their backs are much darker.

These dolphins feed on a wide array of prey, including different fish species, squid, and occasionally crustaceans. Their hunting techniques are diverse and sometimes quite complex, such as using bubble curtains to corral fish. They use echolocation to navigate in dark or murky waters and to locate prey, producing clicks that bounce off objects and return information about location, size, and shape.

Highly intelligent and deeply social, bottlenose dolphins display complex behaviors and possess brains larger than ours. They communicate through a rich language of squeaks and whistles, with each individual having a unique “signature whistle”. They are very active on the surface and are keen bow-riders and wake-riders. We see them playing with our boat many times, and even sometimes “snout-riding” in front of large whales!

Each individual can be identified by the unique nicks and scars on their dorsal fins. Through photo-identification, scientists can monitor their movements and life histories over time. A single photo can be incredibly useful!

It is truly a gift to see these beautiful animals swimming in our waters. Dolphins should always remain wild, free to leap, play, be with their families, and ride the waves as they were meant to.

Last December we encountered a mako shark swimming at the surface, I had seen a couple before, but not like this. We stopped the motor and watched it swim around our boat, coming back and forth slowly, very relaxed, and curious. It looked like it had a malformation on its spine, which probably explains its behavior.

There are two species of mako shark: longfin mako (Isurus paucus) and shortfin mako (Isurus oxyrinchus). This one is a shortfin mako, known for being the fastest shark in the ocean, reaching moving speeds of 50 km/h (31 mph) with bursts up to 74 km/h (46 mph). They are a very active species, often seen breaching the water surface when feeding. This is all thanks to a special circulatory system that allows them to heat their blood, giving them an advantage over their cold-blooded prey.

They have a very hydrodynamic shape, with a pointed snout, a triangular dorsal fin, and a lunate caudal fin. They are dark metallic blue on top and silvery white below, with a distinct color break on the side. Their eyes are very characteristic: big and completely black. Their teeth are long and sharp, and the ones of the lower jaw are visible even when the jaw is closed, giving them a menacing appearance. Shortfin makos are found in tropical and temperate waters throughout the world’s oceans. They are a pelagic species, primarily resident in oceanic waters., but found in coastal waters too.

Like many other sharks, shortfin makos are slow-growing species with males reaching maturity at 7-9 years of age and females not before 18. Their late sexual maturity and long reproductive cycles with long gestation periods, make them highly vulnerable to overfishing.

Shortfin makos are currently considered Endangered by the IUCN Red List. They are targetted by commercial and sport fishing and fished as by-catch too. Like with most shark species, their overharvesting has gone far unquestioned, as we have considered them dangerous, “coldblooded killers”. Since there have been records, shortfin makos have been implicated in 10 unprovoked attacks on humans, one of which resulted in a fatality. I went in the water and snorkeled with this mako, it was cautious and didn’t approach me at all. As opposed to what I believed when I was little, being in the water with a shark doesn’t mean getting eaten by it. Part of the change needed to protect our sharks comes from changing our perception: we need sharks, a healthy ocean needs sharks swimming in it, they are part of balanced ecosystems. We learned to fear sharks, now we must learn to care for them.

We had many dolphins swimming in our bay recently! Common and bottlenose dolphins are the most common species here in La Ventana, but each now and then we find other species, one of them being the pantropical spotted dolphins (Stenella attenuata). Smaller than other dolphins, they are fast, playful, and highly acrobatic, irradiating a contagious joy. They love bow-riding and are very interactive, sometimes making eye contact from the water as they swim. 

As their name indicates, they inhabit tropical and sub-tropical waters worldwide being probably the most abundant dolphins in the world. They are grey, with a darker dorsal cape, and have a dark and light spotting which is highly variable between individuals. They have no spots when they are born and develop them as they age, their spotting pattern is unique and can be used for photo identification. As they glide in the blue water, their spots look like glitter, shining bright. 

Pantropical spotted dolphins often associate with yellowfin tuna, hunting together, last day we saw them, we could see the tuna hunting in front of the group. They feed on different offshore pelagic fish like lanternfish and flying fish, but they also eat squid and crustaceans and they usually hunt at night. Their association with tuna, caused a sharp reduction in their population during the 1980s, as tuna fishing boats were frequently capturing them together. Many dolphins were killed during this time, and more than 4 million were pantropical spotted. This sparked the famous and successful dolphin-safe tuna campaign, which led to changes in legislation, reducing mortality greatly. Thanks to these efforts, pantropical spotted dolphins now are listed as Least Concern by the IUCN. Change is possible, always be an informed consumer and choose what you eat to minimize impacts on our planet!

Recently we had some beautiful cetaceans visiting our bay: short-finned pilot whales (Globicephala macrorhynchus). They were sighted for a few days in our area. Even though they are not super rare to see here, they are not common, so it was fascinating seeing them, but also the fact that we saw maybe hundreds of them, as long as we could see, fins broke the water’s surface.

Pilot whales are odontocetes, toothed whales, and are part of the marine dolphin family. They can look like other dolphins but are much bigger, reaching 12 to 20ft in length (4 to 7m), and have a very characteristic rounded and bulbous melon. This round head gives them their scientific name, from the Latin globus, which means globe, and is an outstanding characteristic that will help you differentiate them. They are black to dark gray/brown with a white anchor-shaped patch in their chest, that looks like a bow tie and have a wide and hooked dorsal fin.

They live in warm waters worldwide and are known for being highly playful and social. They live in matrilineal groups, consisting of a matriarch with her immediate family. They remain in their family group for life. The males leave their groups to mate with members from other families during temporary aggregations of different groups. Females go through menopause, meaning they have important roles once they stop reproducing, like helping care for the calves and as keepers and transmitters of their ecological wisdom.

Short-finned pilot whales feed mainly on squid; they can dive more than 3200ft (1000m) hunting for it. Before we found the pod, we saw pieces of squid floating on the surface, so looks like they had a fest that day!

Pilot whales are often found in aggregations with other species, we saw them hanging out with bottlenose dolphins. They have a complex repertoire of sounds that they use to locate food and for communication. They have strong social bonds, which could explain the frequency of mass strandings in this species.

We enjoyed the presence of several families that formed a huge pod that surrounded us, sometimes coming close to our boat. Mothers traveling with their babies next to them and big males, all together swimming in our waters, a great start to a new season!

 Humpback whales (Megaptera novaeangliae). Winter is a special time of the year. We get the wind that brings joy to many, and we get some special visitors: whales! From the ones in our area, the most common and acrobatic are humpback whales.

Humpbacks are baleen whales, meaning they don’t have teeth, but keratine plates, packed tight together forming a comb-like structure. The baleen works like a giant sieve for filtering small prey.

Found worldwide, in the Northern Hemisphere, they migrate every year between their high-latitude summer feeding grounds to their low-latitude breeding grounds, where they mate and calve during the winter. Adult males measure between 11.5-15m (37.5-49ft) and females are usually a bit bigger, 12-16m (39-52ft). They are easy to distinguish from other whales by their long flippers and their dorsal fin on top of a distinctive hump. They are more active on the surface than any other whale, performing beautiful acrobatics like breaching, and slapping their pectoral fins and tails (lobtailing).

The ones visiting us yearly breed around Cabo area and migrate north for the summer, to Canada or north of the US. They mate between December and March, the pregnant females will return after around 11 months to give birth. Humpbacks usually don´t feed here, so they must feed intensively in the summer. They feed on small fish like anchovies, herring, or sardines, and krill. Sometimes humpbacks can be seen opportunistic feeding in Baja, like on the big sardine balls of the Pacific, who can resist a good snack?

Another special thing about humpback whales is their songs. Females and males produce a wide variety of vocalizations, but only males sing. They create the longest and most complex songs in the animal kingdom.

Humpback whales can be identified by the unique patterns on the underside of their flukes and the serrations on the edges. Photographing a whale fluke, the individual can be recognized. If you take a good photo of underneath the whale tale, you can send it to happywhale.com, where they will try to find a match to your photo. This way, through citizen science, we can see their movement through different years, which is pretty cool! 

Humpbacks are listed as Least Concern by the IUCN, after recovering from the brink of extinction from the whaling times. They are certainly very special creatures and seeing them in our bay every year brings us lots of joy! María Rodriguez-Salinas maria.rodsalinas@gmail.com, salinasmaria.com

Spinner dolphins. One of the last new encounters I really enjoyed, was a playful pod of Spinner Dolphins (Stenella longirostris). It was the first time I ever saw these animals, and now it’s on my top list and I’m looking forward to seeing them again! They are super fun creatures, and the joy and energy they radiate is contagious. Surrounding our boat and swimming with us, spinning and making lots of noise, they filled us up with their joy and put a big smile on our faces.

Locally known as Tornillos (screws), they get their name from their spectacular acrobatic and aerial behavior. They leap out from the water into the air 3 meters (around 9 feet) and spin around their longitudinal axis repeatedly. They can turn up to 7 times before they fall back into the water! They seem to become especially acrobatic after they change from resting behavior to foraging. It’s believed these behaviors are primarily for acoustic signaling or communication, but can also be a way to remove ectoparasites, such as remoras, or courtship behavior.

They inhabit tropical and sub-tropical waters worldwide, with 4 different subspecies, very different from each other in form and color pattern. They are probably one of the most abundant dolphins in the world. Spinner dolphins are relatively small compared with other species. The species’ name, longirostris, is Latin for “long beak,” referring to their elongated rostrum.

Individual dolphins can be identified by their unique dorsal fins. Researchers take photographs of the dolphins’ dorsal fins and then match the shape, nicks, and notches in each fin to a catalog of known individuals.

Spinner dolphins feed at night on species including small fish, shrimp, and squid, diving sometimes more than 600m (1900 ft) to find food. They rest during the day normally, all together in a tight formation.

They are listed as Least Concern in the IUCN Red List, but the eastern subspecies, which is the one in Baja, is listed as Vulnerable.

Next time you are out in the sea, if you happen to find some very playful dolphins, a bit smaller and with a long beak, breaching, and spinning non-stop, chances are you found them! María Rodriguez-Salinas maria.rodsalinas@gmail.com, salinasmaria.com

 For the first time, November has been declared Coral Bleaching Awareness Month. This year, coral reefs worldwide are facing a particularly hard one, mainly due to El Niño meteorological phenomenon. During El Niño, the Pacific Ocean is much warmer, affecting global weather patterns. You probably have noticed the water in the bay is much warmer compared to other years. Though El Niño is a natural phenomenon, on a warmer planet it can have stronger effects.

But how does coral bleaching relate? Bleaching is a stress response caused by different factors, one of them is an increase in water temperature. Corals live in symbiosis with a unicellular photosynthetic organism known as zooxanthella. Zooxanthellae are dinoflagellates from the genus Symbiodinium that live within the coral tissue. In this intimate relationship, zooxanthellae contribute to corals’ nutrition, providing them with the products of photosynthesis. In exchange, they get protection and nutrients. Zooxanthellae can provide up to 90 % of the corals´ energy needs and without them, their growth would be too slow to create reef structures. Because of their photosynthetic pigments, Zooxanthellae are also responsible for the corals´ colors.

Under environmental stress, corals expel their partners. Without them, they lose their color, and we see their white skeletal structure through their transparent tissues. Besides losing their color, corals lose their main energy source. If the conditions go back to normal soon, zooxanthellae return, and corals recover. If the stress lasts too long, the corals starve to death.

Coral bleaching has complex causes, climate change is a main contributor to it. Healthier reefs have better chances to survive. Water quality is vital for coral reefs’ health: less pollution, less trash in the ocean, reef-safe sun protection, reducing CO2 emissions, fishing regulations to ensure herbivores (parrotfish, surgeon fish…) can control algae growth… All of these and more,  are necessary actions to preserve our reefs, not just because it would be a crime to lose their beauty, but because they have vital functions in our ocean: if reefs go, we go.

More on this coral bleaching awareness month here. María Rodriguez-Salinas maria878@hotmail.com, Instagram: maria_salinas_scuba

It is that time of the year again! Every spring we have a very special gathering in our front yard: thousands of rays aggregate in a breathtaking spectacle. They are Munk´s pygmy devil ray or Mobula munkiana, locals know them as “tortillas”, because the sound they make when jumping out of the water, reminds the clapping of hands produced while making tortillas.

They are cartilaginous fish, related to sharks, and they inhabit the Eastern Pacific Ocean, from Mexico to Peru. They reach a maximum disc length of 4.2 ft (130 cm), with an average of 3 ft (100cm). They are filter feeders, and they follow the zooplankton blooms, moving around the Baja peninsula with them. This time of the year, they can be seen in our area, when the conditions are ideal for feeding and reproduction. All around the bay, they can be seen swimming gracefully in the water, hundreds of them together, moving their fins like birds flying, it is truly nature´s wonder. But they can also be seen out of the water: moving their wings and gaining enough momentum to propel themselves in acrobatic jumps, sometimes many of them at the same time. Nobody knows exactly why they jump, there are different theories, but I like thinking it is just pure joy.

For years they were fished till they were put in severe danger of extinction. They are very sensitive to overfishing because they have slow reproductive strategies, like many other cartilaginous fishes. They are aplacental viviparous and they only give birth to one pup, after a gestation period of 12 months, so it takes them a long time to recover after the removal of many individuals. Now they are protected, and we have seen increasing numbers, but they are still listed as vulnerable in the IUCN Red List. One of their main threats is bycatch from coastal fishing nets. Swimming with them is a great attraction for ecotourism, making them way more valuable alive than dead and favoring conservation efforts.

Common dolphins (Delphinus delphis) are the most common cetacean in the world, they are found worldwide, through tropical and temperate waters, nearshore and offshore. Despite their name, they are not the dolphin we have in mind as the “classic dolphin”, being this one the bottlenose dolphin, popular in media or aquariums. Common dolphins have a well-defined long beak, a black-grey back, and a dark patch around the eye, they can be easily recognized by a pale to tan hourglass or crisscross pattern on the sides of their bodies.

They form large groups for hunting and socializing, it is not rare to see hundreds of them in a group. Sometimes, they can form bigger groups called “super pods”, gathering thousands of individuals. They are very playful when they swim in groups and enjoy breaching and playing with waves, they are known for swimming along with boats, either racing at the front or playing at the wake that is formed behind.

Because of their wide distribution, they have a varied diet, feeding on schooling fish like anchovies and sardines, among other species, and enjoy eating squid too. They have been recorded to make dives up to 200 meters (660 ft) deep.

Recently we had big groups of common dolphins in the bay, and what is even better: there were many babies with them! Given that newborn calves measure 7 to 100cm (2.3 to 3.3 ft) I would say these babies were recently born, I had never seen such

Today I want to introduce you to one of the most fascinating marine creatures. These beautiful and delicate shells you see, didn´t belong to a snail or a crab, they belonged to an octopus, a female octopus to be more precise.

Paper nautiluses or argonauts are a group of pelagic octopuses. Unlike their ground dwelling cousins, they spend their lives drifting in the water column, so they evolved in clever ways to adapt to this environment. Argonauts exhibit extreme sexual dimorphism in size, lifespan and features. Females can grow up to 30 cm (12 inches), with their shells while males rarely reach more than 2cm (0.8 inches). Males only mate once in their short lifetime, but females can reproduce many times during their lives. Females have been known since ancient times, because of a unique characteristic, while males were only described in the late 19th century.

The most particular feature of these animals belongs to females too: they have two special tentacles that secrete calcite. After mating, they start producing a delicate papery shell, lay their eggs inside it and get cozy themselves. They capture air at the surface and then seal it inside the shell, using it for buoyancy control, like a hot air balloon. They can control the size of the air bubble to keep their position in the water column. This way they travel, following the current accompanied by their eggs without expending energy.

A paper nautilus’ shell is a rare finding, if you are lucky to find one, treat it carefully, it’s a little and delicate treasure, a part of a creature with a unique life story!