In a groundbreaking discovery, a team of international marine biologists has documented the highest known count of deep-sea species living in methane seeps off Costa Rica’s Pacific coast. With nearly 500 species recorded—including at least 58 previously unknown to science—this research is not just a milestone in deep-sea exploration, but a testament to the hidden wonders of the ocean.
While Costa Rica is often celebrated for its lush rainforests, volcanoes, and rich biodiversity on land, this new study proves that its underwater world is just as fascinating. From deep-sea corals to unusual crabs, the ocean floor off Costa Rica is teeming with life, much of which has remained unexplored until now.
But why should the average person care about a bunch of tiny, unseen creatures thriving in the depths? Well, beyond the sheer marvel of discovery, these methane seeps hold crucial clues to the future of marine ecosystems, climate science, and even potential medical advancements.
Let’s dive into the details of this unprecedented exploration and what it means for Costa Rica, the scientific community, and the broader global conversation on conservation and biodiversity.
The Largest Deep-Sea Species Count Ever Recorded
The research, published in ZooKeys on January 3, 2025, offers the most comprehensive catalog of deep-sea biodiversity ever compiled from a single methane seep region. Led by Scripps Institution of Oceanography at UC San Diego, in partnership with the University of Costa Rica and its Museum of Zoology, this decade-long project (2009-2019) involved:
- Five major research expeditions
- 63 deep-sea submersible dives
- Hundreds of specimen collections and DNA analyses
The final results? A staggering 488 species identified, marking the highest biodiversity count ever recorded in a single seep or vent region.
Perhaps the most astonishing part: of these species, only 131 had been previously described. At least 58 species were entirely new to science, and 299 others remain in a taxonomic gray area, meaning they likely include even more undocumented species.
According to lead author Charlotte Seid, a senior scientist at Scripps, the goal is to create a freely available resource that strengthens research and conservation efforts. She hopes this Costa Rican deep-sea inventory will inspire similar comprehensive studies worldwide.
What Are Methane Seeps, and Why Do They Matter?
Methane seeps are underwater ecosystems where methane gas bubbles up from the ocean floor, feeding microbial life that, in turn, sustains a variety of marine creatures. These unique chemosynthetic environments create rich habitats that function independently of sunlight, making them entirely different from coral reefs or other familiar ocean ecosystems.
Key Reasons Methane Seeps Are Important:
- Biodiversity Hotspots – As this study shows, methane seeps harbor an incredible variety of species, many of which are new to science.
- Carbon Storage & Climate Impact – These seeps regulate methane, a potent greenhouse gas, preventing excessive amounts from reaching the atmosphere.
- Potential for Medical Discoveries – Some deep-sea organisms have biochemical properties that could lead to new medicines.
- Indicators of Ocean Health – Studying these ecosystems helps scientists understand oceanic changes, deep-sea food webs, and environmental shifts caused by climate change.
Despite their importance, methane seeps remain vastly unexplored, making discoveries like this all the more critical.
Expedition Highlights: The Hidden Treasures of Costa Rica’s Ocean Depths
The five expeditions covered seeps ranging from 400 to 3,800 meters below the surface, exploring mounds, faults, underwater landslides, and seamount scars along Costa Rica’s Pacific margin.
The teams collected high-definition photographs, DNA samples, and live specimens to understand what thrives in these methane-rich environments. Among the most exciting discoveries:
- Unusual deep-sea crabs
- Never-before-seen coral species
- Bizarre snails and limpets
- Strange echinoids (sea urchins, sand dollars, etc.)
- Rare sponges and fish adapted to methane seeps
Some species were so unique that scientists believe they evolved independently in these deep-sea conditions, completely separate from other marine life.
These findings weren’t entirely unexpected—similar expeditions in Chile’s methane seeps in late 2024 uncovered another 60 new species. However, Costa Rica’s seeps now hold the record for the highest number of deep-sea species documented in one location.
What This Means for Costa Rica and Global Conservation Efforts
Costa Rica has long been a leader in environmental conservation, from rainforest preservation to marine protected areas. However, this discovery raises important new questions about deep-sea conservation.
Currently, Costa Rica’s marine protected areas focus on coastal regions and coral reefs, but methane seeps remain largely unprotected.
Why does this matter?
- Deep-sea mining and industrial fishing pose serious threats to these habitats.
- Climate change and ocean acidification could disrupt methane seep ecosystems.
- Illegal trawling and pollution are increasingly damaging deep-sea biodiversity.
If Costa Rica wants to maintain its global reputation as a conservation leader, it may need to take proactive steps to protect these newfound ecosystems.
Possible conservation actions could include:
Establishing marine reserves around methane seeps. Expanding research funding for deep-sea studies. Implementing international agreements to prevent deep-sea exploitation.
The Role of Private Organizations and Global Research
This research was partially funded by the National Science Foundation, with additional support from the Schmidt Ocean Institute, a private organization dedicated to deep-sea exploration.
Notably, this isn’t the first major discovery made possible by private-public partnerships. The Schmidt Ocean Institute also led the groundbreaking expeditions off Chile, which discovered 60 new species in late 2024.
Given how difficult and expensive deep-sea research is, collaboration between governments, private donors, and international institutions will be crucial to ensuring that these ecosystems remain protected and understood.
A New Frontier for Costa Rica’s Biodiversity
Costa Rica has long been a world leader in protecting biodiversity, but this study proves that the country’s conservation efforts must now extend below the ocean’s surface.
With nearly 500 species identified—and at least 58 completely new to science—Costa Rica’s methane seeps are one of the richest and most unique deep-sea ecosystems ever documented.
Key Takeaways:
Costa Rica now holds the record for the highest number of deep-sea species documented in one location. Methane seeps play a crucial role in biodiversity, carbon storage, and potential medical discoveries. The study was a decade-long effort involving 28 scientists from 22 institutions worldwide. Deep-sea conservation should become a national priority to protect these fragile ecosystems.
What’s Next?
Will Costa Rica step up to protect these deep-sea treasures? With global interest in deep-sea mining, fishing, and industrial exploitation growing, the time to act is now.
After all, Costa Rica has always been a pioneer in conservation—why stop at the water’s edge?
