The Beacon: Michael Stephens's blog

How to Hunt a Lionfish

lionfish

Success! Bagging these invasive species is good for the reef habitat ©Michael Stephens

One fish is rapidly becoming one of the biggest problems facing the fragile food web of coral reefs in the U.S.: the lionfish. Lionfish are native to the Indo-Pacific region, but are an invasive species in the Caribbean and Atlantic.

In their native waters, lionfish are at the top of the food chain, and are ferocious hunters. They are equipped with dangerous venom-filled spines that run along their dorsal, pectoral, and anal fins. Although they are venomous, they are not poisonous, and are safe to eat once you cut the spines off – and are actually quite tasty!

Twenty years ago lionfish could only be seen in their native habitat in the Pacific, as well as in many aquariums in the United States, but today they can be seen off the eastern seaboard of the U.S. and everywhere in the Caribbean. They are thought to have been accidently released when a hurricane in the late 1990s destroyed a beachfront aquarium in Florida. The fish immediately colonized the Florida Keys, and their eggs floated in the currents around the Caribbean. Scientists were left to watch in horror as the lionfish spread in a predictable pattern around the Caribbean Sea along the current patterns.

Lionfish are voracious feeders, and have no natural predators here, which has resulted in an exponential growth of their population. Plus, they spawn year-round and each brood can have tens of thousands of eggs. They are especially worrisome in the Caribbean since they prey on juvenile fish species, including the endangered Nassau grouper and other recovering fish species.

Unfortunately, there is no simple solution to solving the problem. The population has established itself to the point where eradication appears futile. But every little bit helps, and I myself have hunted the pesky predators all across the Caribbean; from beaches in Florida to the pristine reefs of the Turks and Caicos Islands, and in the world’s second longest barrier reef off the coast of Belize.

There are two ways to hunt lionfish. The easiest is with a spear gun, and the other is by trapping the fish in between two nets. The key to hunting lionfish is to move slowly and stalk the fish so as not to spook it. When threatened, they will swim into small crevices that make them nearly impossible to reach. When using nets, they key is to herd the fish into one net by chasing it from behind with the other. This is difficult because you have to anticipate where the fish will swim to. Using a spear gun is much easier, but can attract sharks, who want to check out the fresh piece of meat you just snagged.

There are endless ways to eat lionfish; my personal favorites are lionfish pizza and lionfish-cakes (crab cake style). Lionfish is a flaky white fish and can be used in recipes for halibut, cod, tilapia, and haddock.

Next time you venture into the water in the Caribbean, be on the lookout for this invasive species, just don’t get too close! Learn more about the Lionfish invasion at http://www.reef.org/lionfish.


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Uncovering Surprising Blooms in the Arctic

polarbear

A changing Arctic spells bad news for polar bears and other animals ©Michael Stephens

Last summer I had the amazing opportunity to be on board the U.S. Coast Guard Icebreaker Healy, in partnership with N.A.S.A.’s ICESCAPE mission to study the effects of ocean acidification on phytoplankton communities in the Arctic Ocean. We collected thousands of water samples and ice cores in the Chukchi and Beaufort Seas.

While in the northern reaches of the Chukchi Sea, we discovered large “blooms” of phytoplankton under the ice. It had previously been assumed that sea ice blocked the sunlight necessary for the growth of marine plants. But the ice acts like a greenhouse roof and magnifies the light under the ice, creating a perfect breeding ground for the microscopic creatures. Phytoplankton play an important role in the ocean, without which our world would be drastically different.

Phytoplankton take CO2 out of the water and release oxygen, almost as much as terrestrial plants do. The ecological consequences of the bloom are not yet fully understood, but because they are the base of the entire food chain in the oceans, this was a monumental discovery that will shape our understanding of the Arctic ecosystem in the coming years.

The Arctic is one of the last truly wild places on our planet, where walruses, polar bears, and seals out-number humans, and raised their heads in wonderment as we walked along the ice and trespassed into their domain. However, their undeveloped home is currently in grave danger. The sea ice that they depend on is rapidly disappearing as the Arctic is dramatically altered by global warming.

Some predictions are as grave as a seasonally ice-free Arctic by 2050. Drilling for oil in the Arctic presents its own host of problems, most dangerous of which is that there is no proven way to clean up spilled oil in icy conditions. An oil spill in the Arctic could be devastating to the phytoplankton and thereby disrupt the entire ecosystem. The full effects of such a catastrophe cannot be fully evaluated without better information about the ocean, and we should not be so hasty to drill until we have that basic understanding.  

Unless we take drastic action to curb our emissions of CO2 and prevent drilling in the absence of basic science and preparedness, we may see not only an ice-free Arctic in our lifetimes, but also an Arctic ecosystem that is drastically altered.


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