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Marine Life & Conservation

Lionfish: a very spiny problem!

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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:

  1. Where should they be?
  2. How did they get into the Caribbean?
  3. What is all the fuss about?
  4. 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

For more from CJ and Mike please click here.

CJ and Mike are dive instructors who have travelled all over the world pursuing their passion for the underwater world. CJ is a PADI MI and DSAT Trimix instructor with a degree in Conservation biology and ecology, who has been diving for 15 years. She loves looking for critters and pointing them out for Mike to photograph. Mike is a PADI MSDT who got back into diving in 2010. He enjoys practicing underwater photography and exploring new and exciting dive locales, occasionally with more than one tank. Follow more of their diving adventures at www.bimbleintheblue.com.

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Marine Life & Conservation

Dive Guides invited to apply for the Green Fins Dive Guide Scholarship

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Reef-World’s campaign is helping dive guides in need receive Green Fins environmental certification

The Reef-World Foundation – international coordinator of the UN Environment Programme’s Green Fins initiative – is calling for dive guides to submit their application for the Green Fins Dive Guide Scholarship.

As a result of the Scholarship campaign, dive guides working around the world – including Brazil, the Philippines, Egypt, Colombia, South Africa, Indonesia and Turkey – have received their certificate proving their status as a Green Fins certified dive guide. Yet, thanks to funding from Reef-World’s partner Paralenz, 149 more scuba diving guides will be able to receive their Green Fins Dive Guide e-Course environmental certification.

Dive guides who meet the criteria (outlined below) can apply for the scholarship at any time through the Green Fins website. To be eligible for the scholarship, guides must:

  • have completed and passed all modules of the Green Fins Dive Guide e-Course
  • be able to demonstrate they or their employer are not financially able to purchase the certificate
  • be a national of a country which receives official development assistance from the Development Assistance Committee (DAC) of the Organisation for Economic Co-operation and Development (OECD).

The Scholarship was created in response to feedback from dive guides who had passed the Green Fins Dive Guide e-Course and were keen to download and display their personalised electronic certificate but were not financially able to cover the associated cost (£19 / $25 USD). The personalised electronic certificate can be displayed to entice eco-minded guests by informing them the guide has received this vital environmental certification and is aware of how to reduce the negative environmental impacts associated with diving.

Diving related damage to sensitive marine ecosystems, including coral reefs, is becoming an increasingly significant issue. This damage makes them less likely to survive other local and wider stressors, such as overfishing or run-off from land containing pollutants and plastic debris as well as the effects of climate change, such as rising sea temperatures. The Green Fins Dive Guide e-Course, created with the support of Professional SCUBA Schools International (PSS) and running on their innovative EVO e-learning platform, teaches dive professionals how to prevent diving-related damage to coral reefs by following the highest environmental standards and better managing their guests to prevent damage to the reef.

Sam Craven, Programmes Manager at The Reef-World Foundation, said: “We’re proud to be offering dive guides around the world the opportunity to become Green Fins certified; no matter their background. Both the e-Course and the Scholarship have been a great success so far and we’re delighted to see so many dive professionals demonstrating their commitment to sustainable tourism by taking the course. We urge dive guides who haven’t yet taken the course to consider taking this step and welcome Scholarship applications from anyone who meets the criteria. Together, we can protect coral reefs through sustainable diving and we’d love as many dive guides as possible to join us.”


Dive guides who want to be considered for scholarship can visit www.greenfins.net/green-fins-dive-guide-scholarship-applications to apply.

To donate to the Green Fins Dive Guide Scholarship Fund, please visit www.greenfins.net/appeal/sponsor-a-dive-guide.

Supporters who are interested in helping additional dive guides receive their certifications can also donate to Sponsor a Dive Guide.

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Marine Life & Conservation

Go Fish Free this February

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There are no longer plenty more fish in the sea! Fish Free February challenges you to help protect our oceans by removing seafood from your diet for 28 days and helping to raise awareness of the issues caused by intensive fishing practices.

Our oceans are in a state of global crisis, brought about by ocean warming, acidification, pollution, and habitat destruction. However, the biggest immediate threat to ocean life is from fisheries. Each year an estimated 1-2.7 trillion fish are caught for human consumption, though this figure does not include illegal fisheries, discarded fish, fish caught to be used as bait, or fish killed by not caught, so the real number is far higher. It is no wonder then, that today nearly 90% of the world’s marine stocks are fully exploited, overexploited or depleted. If we do not act fast, overfishing and damaging fishing practices will soon destroy the ocean ecosystems which produce 80% of the oxygen in our atmosphere and provide three billion people with their primary source of protein.

Fish Free February, a UK-registered charity, is challenging people around the world to take action for marine life in a simple but effective way. Take the Fish Free February Pledge and drop seafood from your diet for one month, or beyond. Fish Free February wants to get people talking about the wide range of issues associated with industrial fishing practices and putting the well-being of our oceans at the forefront of dietary decision-making. A third of all wild-caught fish are used to create feed for livestock, so Fish Free February urges us to opt for plant-based dishes as a sustainable alternative to seafood, sharing our best fish-free recipes on social media with #FishFreeFebruary and nominating our friends to do the same.

“Not all fishing practices are bad” explains Simon Hilbourne, founder of Fish Free February. “Well-managed, small-scale fisheries that use selective fishing gears can be sustainable. However, most of the seafood in our diet comes from industrial fisheries which often prioritise profit over the well-being of our planet, resulting in multiple environmental challenges. In some cases, the fishing industry has even been linked to serious human rights issues such as forced labour and human trafficking! Fish Free February hopes to shed more light on fishing practices, create wider discussion around these issues, and offer solutions to benefit people, wildlife, and the natural environment.”

To learn more about these issues and to take the Fish Free February pledge visit www.fishfreefebruary.com

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This is the perfect start to your 2021 diving season… and at an incredible lead-in price of just £885 per person.

Jump on board the latest addition to the Emperor fleet and enjoy diving the famous sites of the Red Sea with this fantastic special offer. This itinerary takes in the wonderful South & St Johns from 26 February – 05 March 2021.  

Subject to availability – limited flight seats at this price so don't delay!

Call Diverse Travel on 01473 852002 or email info@diversetravel.co.uk to book your spot!

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