10 Fascinating Marine Species You Might Encounter in Costa Rica

10 Fascinating Marine Species You Might Encounter in Costa Rica

Costa Rica is a dream destination for ocean lovers, scuba divers, and marine biologists alike. With its stunning Pacific coastline and thriving coral ecosystems, it offers an unparalleled opportunity to witness marine biodiversity at its best. From tiny nudibranchs to curious octopuses and majestic manta rays, the waters around Costa Rica are teeming with life.
In this blog, we highlight 8 of the most fascinating marine species you might encounter while scuba diving in Costa Rica — and why marine conservation is crucial to their survival.
marine species costa rica

The Octopus

octopus

Highly intelligent and masters of disguise, octopuses are some of the most captivating creatures in Costa Rica’s coral reefs. You’ll often spot them hiding in crevices or changing colors to blend with their surroundings.

Octopuses are a favorite among night divers, as they tend to be more active after dark. Conservation efforts help protect their reef habitats from overfishing and degradation.

Fun Fact: Octopuses have three hearts and blue blood!

Nudibranchs

Nudibranchs are small, brightly colored sea slugs that are often considered the jewels of the reef. Their incredible variety and vivid hues make them a favorite for macro photography.

While they might be tiny, they play a significant role in marine ecosystems by feeding on sponges, hydroids, and other invertebrates. Protecting coral in Costa Rica ensures a healthy environment for these delicate species.

Conservation Tip: Avoid touching or disturbing reef surfaces where nudibranchs live.

nudirbranch

Spotted Eagle Ray

eagle ray

With its graceful wingspan and distinctive white spots, the spotted eagle ray is an awe-inspiring sight. You might see them gliding through open water or foraging in sandy seabeds around coral reefs.

These rays are sensitive to human disturbance, and like many marine animals, they are vulnerable to habitat loss. Scuba diving in Costa Rica offers a chance to see them up close — without harming their environment.

Size: Can reach up to 3 meters across!

Moray Eels (Gymnothorax spp.)

Often misunderstood due to their fearsome appearance, moray eels are actually shy and non-aggressive. You can spot them peeking out from holes in the reef, their mouths opening and closing to help them breathe.

Morays play a vital role in the reef ecosystem by helping control fish populations. Keeping Costa Rica’s coral reefs healthy through marine conservation ensures a balanced food web that includes species like these.

Diving Tip: Use a flashlight on reef dives to spot them more easily.

moray eel

White-Tip Reef Shark

Shark

White-tip reef sharks are a common sight on many dive sites across the Pacific coast of Costa Rica. They are generally calm and often seen resting on the seafloor during the day.

They are a top predator in reef systems and help maintain ecological balance. Protecting coral Costa Rica means preserving critical habitat for these sharks and their prey species.

Status: Near Threatened (IUCN Red List)

Parrotfish (Scaridae family)

Parrotfish are colorful, coral-chewing herbivores that help reefs thrive by cleaning algae off the coral surface. Their “beak-like” mouths break down coral, which they excrete as fine sand — contributing to beach formation!

Marine conservation efforts in Costa Rica help regulate fishing practices to ensure healthy populations of parrotfish, vital for reef regeneration.

Eco Fact: One parrotfish can produce up to 100kg of sand per year!

parrotfish

Seahorse (Hippocampus spp.)

seahorse

These enchanting creatures are masters of camouflage, often clinging to coral branches or sea fans with their tails. Spotting a seahorse while scuba diving in Costa Rica is a rare and magical experience.

Unfortunately, seahorses are threatened by habitat destruction and the curio trade. That’s why marine conservation in Costa Rica includes habitat protection and public education.

Conservation Note: Never collect or handle seahorses — observe from a distance.

Pacific Green Sea Turtle (Chelonia mydas agassizii)

One of Costa Rica’s most iconic marine animals, the Pacific green sea turtle nests along many of the country’s beaches and feeds on seagrass and algae near coral reefs.

Scuba divers can often spot them resting in reef areas or gracefully swimming between coral heads. Marine conservation efforts are vital to protect their nesting beaches and feeding grounds.

Conservation Status: Endangered

green turtle
PADI Pro

Why Marine Conservation in Costa Rica Matters

Every one of these marine species — from the tiniest nudibranch to the majestic reef shark — depends on a balanced, thriving ocean ecosystem to survive. Costa Rica’s coral reefs are biodiversity hotspots, but they are under constant threat from climate change, pollution, and overfishing.

Our coral restoration program in Costa Rica is dedicated to reviving damaged reefs, planting resilient coral species, and educating the next generation of ocean stewards. When you support or volunteer with marine conservation projects, you directly contribute to the survival of these incredible creatures.

Join Us in Protecting Costa Rica’s Ocean Life

Whether you’re a scuba diver, marine biology student, or simply passionate about the ocean, you can help make a difference. Join our coral restoration projects or take a marine education course and be part of the solution.

10 Ways to conserve sharks (without leaving your couch)

10 Ways to conserve sharks (without leaving your couch)

2020 has been a very strange and emotional year for all of us, above the surface and below. While we have been stuck in lockdown, sharks have been falling victim to numerous dangers caused by humans. Sharks are under more threat than ever before, and I’m here to show you 10 simple ways that you can help conserve sharks without even leaving your couch – how COVID-19 friendly!

1. Sign Petitions

Signing petitions that demand protection of shark populations worldwide is the quickest thing that you can do to make a difference right now.

A petition being organized by Change.org needs all hands on deck to ban fishing on the high seas surrounding the Galapagos Islands, just off the coast of Ecuador. If you are not familiar with what is happening, there are over 200 fishing vessels operating at the edge of the protective zone. The Galapagos Islands are one of the largest biodiverse ecosystems in the world, being home to many species of shark. These vessels are practicing unsustainable fishing practices, resulting in the bycatch of thousands of sharks and completely decimating the shark populations in a protected area.
Click here to sign the petition.

For more petitions check out Support our Sharks, they take the time to gather any and all petitions surrounding shark conservation. I even found some concerning my home country, you may be surprised by what you find.

2. Get Involved with Conservation Groups

Coral fragments taking time to grow at one of our nurseries

There are many conservation organizations making a big impact daily, and you can get involved with just the click of a button.

Like with us! Marine Conservation Costa Rica runs numerous conservation programs that you can join once the travel bans are lifted. In the meantime, you can Adopt a Coral! Coral reefs are home to sharks, they use them to graze and hunt for food, keeping the ecosystem of the reef balanced. By adopting a coral, you are supporting our coral restoration project that is bringing life back to our reef. With your purchase, you will have the opportunity to name your little coral and receive a certificate with all of its information, even the GPS location!

PADI has been a long time partner with Project AWARE, a global movement committed to ocean protection. They make it super easy to donate to their initiatives, and they invest 25% of their donations into shark and ray conservation.

Other conservation groups that we know and love are Sea Shepherd, Fins Attached, and Sharkwater, so check ’em out.

3. Adopt a Shark

This is a fun and unique way to do your part in conserving sharks, plus it would make a great gift for someone special!

There are a few companies that allow you to “adopt a shark,” such as Oceana and Shark Trust. You give a small donation in exchange for an adoption pack and certificate telling you all about the shark that you have just helped sponsor. The majority of proceeds go toward shark research and conservation. I call that a win, win.

4. Reduce Your Seafood Consumption

Large scale commercial fishing practices negatively impact shark populations in multiple ways. Humans like to eat boney fish, and inconveniently so do sharks, so by fishing on a large scale we are depleting their primary source of food. Sustainable fishing is important because sharks often become victims of hooks or nets which are meant for other fish, but they become entangled while chasing an easy meal. By simply reducing your consumption of seafood, you can reduce the number of sharks killed each year.

5. Choose Sustainable Seafood

Unsafe fishing practices and bycatch pose the largest threat to our world’s sharks. Bycatch is when a fish or other marine species are accidentally caught while fishing for something else. This is most common with commercial long-line fishing. According to WWF, 3.3 million sharks are victims of bycatch every year, and that’s only in the Pacific Ocean! Do your research and choose to buy fish from properly managed and sustainably run fishermen. Buy small, and buy locally.

Pro Tip: If you are from the United States, The Monterey Bay Aquarium offers a great guide to sustainable seafood in every state in their Seafood Watch Consumer Guide, just select your state and numerous options will appear for your area!

6. Education Is Power

Learn as much as you possibly can about sharks, learn about their habitats, their behavior, different species, and then educate yourself on how human practices are putting them in danger. Investing in your own education is powerful, it builds knowledge, creates confidence, and opens countless doors of opportunity. The more educated you are about them, the more ways you can find to help Conserve sharks. Plus, you might just inspire someone to do the same.

7. Use Your Voice

Social media is not just a place for stories, status updates, and pictures. It is also a powerful tool that you can use as a platform for your voice. Start sharing photos, articles, and updates about sharks. Even if you catch the attention of one person, you have done your job. As Jacques-Yves Cousteau once said, “People protect what they love,” so show people that sharks are intelligent creatures worth protecting.

Spread the word – an ocean without sharks is more frightening than an ocean with sharks.

8. Vote Wisely

Support legislation that stops shark fishing, protects ecosystems, and ends unsustainable fishing practices. Before election day, make sure to research your local candidate’s values and promises. Use your right to elect officials who actively support ocean and marine life conservation.

9. Reduce, Reuse, Recycle

coral research projects
A recent dive for debris where we found bottles, flip-flops, fishing lines, and food wrappers.

Sharks become entangled in plastic fishing gear and other plastic materials, often leading to irreversible damage or death. Also, sharks often confuse plastic for food, and so do the smaller fish who the sharks then eat, resulting in all levels of the food chain ingesting plastics.

So, what can you do? Reduce, Reuse, Recycle of course!

The most common forms of trash found on land and underwater clean-ups by us are bottle caps, straws, plastic cutlery, plastic bags, food wrappers, and bottles/cans.

1. Purchase reusable drink and food containers, beeswax wraps are a great alternative to cling wrap.
2. Buy a reusable bag such as one made from cotton or recycled materials.
3. Contact your local recycling depot and become familiar with what materials they can and cannot recycle.

10. Check Your Cosmetics

Yep, you read that right!

Chances are that you’ve used cosmetics or sunscreens containing shark products before, you just didn’t know it. The ingredient to look out for is “squalene,” which is shark liver oil. Squalene is most commonly used in anti-aging creams, hair treatments, lipsticks, sunscreen, and many others.

According to The Rob Stewart Sharkwater Foundation, about 50 different species of shark are fished for their liver oil, even species that are considered endangered such as the deep-sea shark, because their liver is 20% of their body weight.

Before you buy your next product, check to see that it has the “cruelty-free” stamp or that it is a vegan / plant-based product.

Make Big Waves For Change!

We know that getting out there and doing hands-on conservation work is hard at the moment with travel bans, restrictions, and lockdowns. Although, these 10 easy things are impacts that you can make right now, without leaving your bed or couch, to ensure a better future for our oceans and our sharks! Once restrictions ease, plan a beach cleanup with friends, go diving with sharks, or plan a volunteer holiday to learn more about our ocean’s diverse ecosystems! The sharks are counting on you.

The Stay at home Blenny – 7 fascinating facts

The Stay at home Blenny – 7 fascinating facts

blenny fascinating facts

With people in lockdown all around the world we are all looking for inspiration from different avenues. As we dream of the ocean from the safety of our homes, I thought we could look towards the Blenny. A beautiful example of a stay at home fish. The Blenny is the common name of various species of extremely numerous small fishes belonging to the suborders Blennioidei (blennies) and Notothenioidei (Antarctic blennies). There are hundreds of different species of blennies around the world and they are all fascinating creatures. Here are some amazing facts about this stay at home fish that will hopefully inspire you.

1.They can be great copycats

Many blennies demonstrate mimicry of other species of fish. By mimicking other species it allows the blenny to get up close to other fish. For example, if they are mimicking a cleaner wrasse other fish pass by to let them clean. The blenny then takes nips or larger bites out of the unsuspecting fish. 

2.They like to hide out

Many blennies have a secretive lifestyle. This protects them from predation. They hide on the sea floors in shallow water. Many of them with cryptic coloration making them very hard to spot.

Blenny in Costa Rica
Photo taken by Gina Nicole

3. They can have a nasty bite

One genus of blenny is truly venomous and that is the Meiacanthus. This particular blenny can inject venom from its mandibular, hollow fangs. Their venom contains an opioid-like protein which they use to defend themselves.

4.They like a varied menu

Many blennies are detritivorous. This means that they consume dead plant and animal matter. Some blenny species are mainly herbivorous, and others are partially to completely carnivorous.

5.They can hang out on the land too

One species of blenny is called the rockskipper (Istiblennius zebra).It is a small Hawaiian blenny and is a representative of several that live along shores and can hop about on land as well as hang out in ocean.

6.They are a unique fish when it comes to feeding their young

One species of blenny, the European eelpout or viviparous blenny (Zoarces viviparus) is very unique. They are native to the English Channel and Baltic sea. They are the only fish known to suckle its offspring. This is done when each young attaches its mouth to the opening of a canal inside the mother. The canal leads to an ovarian follicle, which then dispenses fats, proteins, fluid saturated with oxygen, and other nutrients to them.

Blenny in Costa Rica - Photo taken by Gina Nicole
Photo courtesy of Gina Nicole

7.They are small but mighty

With so many different species of blennies in the world they all have varying temperaments.Some are calm and some can be aggressive. An example if the The Hawaiian Runula goslinei and the Pacific R. tapeinosoma blennies. Both of these are small but will readily attack a swimmer or diver by biting them.

Octopus Ecology program

Octopus Ecology program

 Come and learn about one of our exciting scuba diving programs for our interns and volunteers and it is all about one of our favorite critters here on the reef. The Octopus. The program is called Octopus Ecology and with it you will learn all about them.

 

 

 

octopus ecology

The octopus is one of the most interesting creatures here on the reef. The are very often considered to be one of the most intelligent creatures of all invertebrates. They have three hearts and all of their tentacles have a mind of their own. That is three quick facts that are amazing.

octopus at night swimming

During the program the following themes are covered;

  • the morphology of Octopus and the roles of them within the ecosystem.
  • How to find the octopus on the reef
  • How does the octopus feed and reproduce
  • How does the octopus behave and learn.

Finally we look at their conservation status and what species we can find locally as well as how we record and observe them. This is then followed by two dives on the reef observing and recording any data we have on them.

So, want to learn more? Then maybe you should sign up for our program. It is available as part of our Marine conservation internships and volunteer programs. It will be taught by our MCCR instructors and includes 2 dives out on the reef looking at Octopus habitats and behavior

If you want to join us on this exciting program then contact us here.

.

The amazing Octopus – 5 fun facts

The amazing Octopus – 5 fun facts

octopus hiding under a rock
Photo by Laura Bori

Octopus are some of our favorite squishy invertebrates of the reef. With their flashing colors and unique behavior it is always fun to look them out and find them. Apart from the fact they have 8 legs, (unless you are Hank from Finding Dory), what else do you know about them? Here are 5 fun facts that firmly put them in the awesome animal category! 

Octopus have blue blood

Rather than the old boring red color, Octopus have blue blood. This is because of a protein that has copper atoms in it that binds itself to the same amount of oxygen atoms. This is completely different to our blood that has iron atoms in it. This protein is what allows the octopus to survive in very cold and very warm waters because it is transported to its vital tissues around their bodies

How many hearts?

An Octopus has 3 hearts of which 2 of them are pumping blood to the gills and the other one pumps blood to their organs. Octopus need more oxygen than other invertebrate species so their 3 hearts allows for them to have a steady flow of oxygen. Their copper based blood is not as good as iron based blood for transporting oxygen throughout the body so their three hearts compensate for that by pumping blood around at a higher pressure. Busy, busy, busy!

octopus on Manuel Antonio Reef
photo by Laura Bori

I thought a chicken had it bad..

Females usually lay around 200,000- 400,000 eggs which varies between species. Once laid, the female octopus guards the eggs until they are ready to hatch. After they hatch the females body essentially starts to destroy itself and the cells basically tear through her tissues and organs until she dies. 

They could join mensa,

Well, maybe not, but Octopus are considered the most intelligent creature of all invertebrates. They have the largest brain to body mass ratio of any of the invertebrates. There have been many studies on octopus through maze and problem solving that have shown that octopus have long and short term memory. Hey, they can even predict world cup games apparently!

They have been around for a long time

The oldest known fossil of an octopus is 296 million year old. It is called the Pohlsepia. Researchers have identified marks of 8 arms, 2 eyes and even the possibility of an ink sac on the fossil.