Marine Life & Conservation Blogs
Lionfish: a very spiny problem!
For anyone who has been diving in the Caribbean in the last few years, you have probably heard of the lionfish problem. Having taught marine biology & conservation in the Caribbean for several years, it’s a question I get asked about a lot. This blog explains some of the facts about lionfish and what we can do to help our reefs:
- Where should they be?
- How did they get into the Caribbean?
- What is all the fuss about?
- What you can do to help the reefs?
Where should they be?
Lionfish are a beautiful predatory fish, native to the Indian and Pacific Oceans and the Red Sea.
In their native habitat the lionfish is great to observe and photograph. They are not very common as they have natural predators that keep population down and in balance with the other reef fish (Density/hectare in the Pacific is ~20).
How did they get into the Caribbean?
Unfortunately since 1992, two species of lionfish (Pterois volitans & Pterois miles) are now found in the Atlantic Ocean and the Caribbean Sea, where they are an invasive species. The theory is that captive lionfish were released or escaped off the coast of Florida and the population has spread. Lionfish established themselves in the Caribbean in less than 3 years and range from North Carolina to South America including the Gulf of Mexico. From a few individuals in 1992 the population has now spread out of control to become a major problem in the ecosystem (Density/hectare in Caribbean ~398 in 2012).
What is all the fuss about?
Why are lionfish an issue?
To understand the issue, we first need to know a bit about the fish.
Lionfish biology:
They have venomous tissue within their spines for protection and are generalist carnivores. Adults can grow up to 42cm and have a lifespan of 5-10 years. They become sexually mature in less than a year and spawn in pairs. Females can release 30,000 eggs at one time. Enclosed in a mucus layer, the eggs float to the surface. In a few days the mucus dissipates and the eggs are released to be dispersed by ocean currents.
Habitat & ecology
Lionfish inhabit all marine habitat types (reefs, lagoons, mangroves, sea grass beds, sand patches and artificial substrates) and can handle tropical temperatures all the way down to 10°C. They can also live at a huge range of depths (from shoreline to over 300m or 1000 feet), though they tend to be territorial, so may remain in the same area for up to 7 months. They appear to be attracted to cleaning stations.
So why are they a problem?
Lionfish have no natural predators in the Caribbean. The density per hectare of invasive lionfish is around 20x higher than in their native waters. They consume over 70 species of fish and many invertebrate species and can eat prey up to half their body length (basically they can eat pretty much anything!). This makes them top predators along with sharks, rays and groupers. By colonising mangroves and sea grass beds they pose a major threat to juvenile fish (this is where lots of baby fish live until they are big enough to survive out on the reef).
On heavily invaded sites, lionfish have reduced their fish prey population by up to 90% and continue to consume native fishes at unsustainable rates. Many reefs have been decimated of the native reef fish as the lionfish consume until supply of fish has run out. Once the food has run out, lionfish can survive for 12 weeks with no food, so can move on to other feeding grounds. Reefs without fish don’t function, so the coral also starts to suffer.
Invasive lionfish reproduction occurs throughout the year and as frequently as every 4 days (whereas native Indo-Pacific lionfish breed only once a year!). This means an invasive female lionfish can lay over 2 million eggs/year in the Caribbean. And unlike in the Indo-Pacific, many of these eggs will survive to adulthood. This means the populations are increasing at a phenomenal rate (700% in 4 years!).
Where lionfish containment programs operate, the deep dwelling fish can be very hard to get to in order to kill or capture. So lionfish pose a threat to the integrity of the reef food web and can have wide reaching impacts on commercial fisheries, tourism, and overall coral reef health.
What you can do to help the reefs?
Educate others and spread awareness of lionfish.
EAT THEM!! They are a delicious delicacy (see RECIPES below!). Also eating this fish reduces pressure on fish stocks of native species.
Encourage local restaurants to serve Lionfish and promote consumption by community members.
We need to be the main predator and keep dive sites as free of Lionfish as possible. Though we cannot get all of them, reducing the numbers on the coral reef and shallow water can really help native fish species and coral health.
Lionfish removal:
Spearing lionfish is quick and safe if done properly (Hawaiian Slings can be used very effectively). A tube container is recommended to store captured fish.
Many marine park authorities and islands have licensed spearing lionfish as local removal efforts can significantly reduce lionfish densities and subsequent impacts. Efforts are invaluable for supporting other conservation initiatives like management of marine protected areas, pollution control and fish stock rebuilding in order to help our reefs.
Try our favourite Lionfish Recipes! To see them click here.
- Island Lionfish Fry
- Lionfish Ceviche
- Lionfish Coconut Curry
- Coconut Lionfish with Spicy Mango Dip
- Marinara Lionfish Spaghetti
- Lionfish Tacos with Street Corn and Salsa
- Cajun Spiced Lionfish Fillets with Mango Salsa
- White Wine Lionfish
- Lionfish Sanganaki
- BBQ Lionfish: Kebabs and Parcels
Saba has an exciting new initiative to restore its coral reefs. This new project, running from 2024 to 2026, will focus on reviving key species in the island’s underwater ecosystems. With a collaborative team from the Saba Conservation Foundation (SCF) and Van Hall Larenstein (VHL) University of Applied Sciences, the project aims to restore both corals as well as sea urchins.
This initiative is centered around coral restoration, specifically reviving two essential coral species—staghorn coral (Acropora cervicornis) and elkhorn coral (Acropora palmata). By mapping parent colonies and using a technique known as coral gardening, SCF will create and maintain coral nurseries. These corals will eventually be outplanted at key reef sites around Saba to not only expand the number of coral colonies, but also provide essential fish habitat. The project focusses on installing coral nurseries, training staff with the newest techniques and starting with the restoration of key reef sites.
Reef Cleaners to the Rescue
It’s not just corals getting a makeover—this project also shines a spotlight on the essential role of grazers, particularly sea urchins. VHL is leading the charge on cultivating and restocking two key sea urchin species, West Indian sea egg (Tripneustes) and long-spined sea urchin (Diadema), known for their ability to keep algae in check. By removing algae, which are important competitors of corals, they help the coral to thrive. By restoring these “reef cleaners,” Saba’s project will give corals the breathing room they need to grow, setting the stage for a healthier, more balanced marine ecosystem.
From Tiny Urchins to Big Goals
The project will be funded as part of the Dutch Government’s Nature and Environment Policy Plan (NEPP) 2020-2030 for the Caribbean Netherlands, a comprehensive initiative aimed at conserving and restoring the unique natural environments of the Dutch Caribbean islands, including Saba, St. Eustatius, and Bonaire. This project is aiming for big milestones: build and maintaining coral nurseries, the expansion of urchin cultivation facilities, and the creation of a dedicated research center. By 2026, the project hopes to ramp up coral and grazer restoration, with the ultimate goal of extending these efforts across the Dutch Caribbean. By linking local initiatives to broader regional goals, Saba’s restoration project promises to leave a lasting impact on both the environment and the community.
Find out more about the DCNA at dcnanature.org.
Blogs
Reef-World marks two decades of marine conservation: strengthening impact amid coral reef threats
Empowering ocean stakeholders to tackle future challenges and ensure the survival of coral reefs and humanity
2024 marks the 20th Anniversary of The Reef-World Foundation’s tireless efforts for global coral reef conservation. The UK charity is the international coordinator of the UN Environment Programme’s Green Fins initiative, known as the leading voice in sustainable marine tourism. Today, Reef-World released its 2023-2024 Impact Report outlining a year of substantive growth and impact in its marine conservation programmes.
Impact Report Highlights:
- Impressive improvements in environmental behaviours to protect coral reefs by the marine tourism industry as the global participation of Green Fins increases.
- Continued capacity building for government and NGO staff to effectively manage marine tourism activities in Asia, Caribbean and Red Sea regions.
- For the first time in Green Fins’ 20-year history, tourism operators have achieved ‘Best Environmental Performer’ status by demonstrating the lowest possible environmental impact in their environmental assessments. In 2024, three dive operators achieved this challenging milestone.
- Significant increases in global participation of Reef-World’s innovative digital conservation tools.
- 138 Green Fins dive operator members achieved the strict threshold for PADI Eco Center recognition.
- Developed four new educational materials and translated two into 16 languages to support the marine tourism industry in achieving sustainability targets.
- Establishing a new Reef-World Development strategy and recruiting new roles – Development and Programmes Managers.
- Reef-World’s board welcomes new Chair and Trustees strengthening organisational leadership.
Reef-World started as a one-person mission to inspire and empower communities to act in conserving and sustainably developing coral reefs and related ecosystems. Today, the team of 12 continues to meet this mission by inspiring and empowering the global marine tourism community to be exemplary sustainability leaders by using the Green Fins guidelines and tools to simultaneously use and protect the world’s precious reefs.
In April 2024, the fourth global coral reef bleaching event was confirmed. Reef-World’s work has never been more urgent as the marine environment, and the benefits they provide humanity, continue to be eroded by global threats. The reduction of local threats, like those from the marine tourism industry, is an essential step to ensuring a future where coral reefs survive and continue to support the millions of people who depend on their ecosystem benefits. Reef-World’s work buys time for coral reefs and related ecosystems to be resilient to the impacts of global threats.
“Right now our corals are facing the greatest fight of their existence as the terrifying predictions of the steps towards their complete extinction are starting to come true. But all is not lost, reefs are resilient and they have existed on this planet for millions of years. We must take action now, to buy time for reefs by reducing threats facing them and allowing them to react and adjust to the changing environment they need to survive in.” – Chloe Harvey, Executive Director
Looking Forwards:
Like coral reefs, the Reef-World team needs to be resilient in the face of the complex challenges of the conservation sector. Reef-World has invested significantly in developing a Culture of Care to ensure the well-being of its team on a daily basis, continuing to be an exemplary employer to enable its team to best achieve the mission for coral reef conservation.
With the foundations of a Culture of Care and organisational development laid, Reef-World is emerging from the end of a natural organisation life cycle, that brings the challenges of growth and scale, stronger than ever. With a new strategy in place to generate much needed resources, Reef-World is excited for the opportunities to leap forward, continue to scale our impact and lean into new innovations and untapped opportunities for marine conservation.
We continually strive to become a forward-thinking organisation that delivers on our goals and commitments to our stakeholders with fresh approaches and not being afraid of steering away from a “normal approach.” This approach is not only applied to our programmes of work but also internally and carries over to our Culture of Care for our team.” — JJ Harvey, Operations Director
The Reef-World Foundation is immensely grateful for the continued support of its grant funders: UN Environment Programme, IUCN’s Blue Natural Capital Financing Facility, Adventure Travel Conservation Fund, PADI Aware Foundation, and World Nomads Footprints Program.
Reef-World would also like to express its gratitude to international partners whose vital support has resulted in significant tangible benefits for our work and mission: PADI; Professional SCUBA Schools International (PSS); Explorer Ventures; 1% for the Planet; ZuBlu; Snorkel Venture, GSTC; Dive O’Clock; Seven Dragons; DiveAssure and Eco Beach, without whom these achievements would not be possible.
The full 2023–2024 Annual Impact Report is available on Reef-World’s website.
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