Last spring, I was living on a tall ship that was sailing from Tahiti to Hawaii. On the way, we stopped at Christmas Island, which is part of the nation of Kiribati. While there, we let off two members of our crew so they could fly back to California for other obligations while we continued on our way. Christmas Island is in the middle of nowhere, so they were the only passengers that got onto the plane. Well, the only human passengers. As our friends told us later, they were joined by hundreds of crates of tropical fish.

The fish were part of a subversive yet prominent worldwide trade phenomenon: aquarium trade. The weirdest, brightest-colored, cutest tropical fish are in high demand for aquariums in homes, offices, and businesses. There are two types of home aquariums – freshwater and saltwater – and while nearly all fish in freshwater aquariums are born in captivity and bred, nearly all fish in saltwater aquariums are taken from the wild. The wild being many of the places that I’ve been so fortunate to visit, like Hawaii, the Line Islands, and Palau – some of the most stunning coral reef ecosystems on our planet. Philippines is the biggest exporter of aquarium fish to the United States, followed closely by Indonesia – and both are located in the Coral Triangle, the richest region of coral reef biodiversity in the world.

The reef on Caroline Atoll, Southern Line Islands; Taken by Bryant Irawan

So what’s the big deal if a few small fish are taken out every year? The problem is that it’s not just a few – over 22 million reef fish are taken out of the ocean every year for aquariums, in addition to millions of other types of reef organisms. Half of those fish – 11 million – go to the US alone. There is also an incredible diversity of organisms that are distracted – 2,250 marine fish species and 725 invertebrate species were imported to the US from 2000-2011. Marine fish are vital to coral reef ecosystems because they not only feed larger organisms, but they also keep coral reefs themselves alive. Small fish eat algae, and without them, a coral reef would soon become covered by algae, which stunts the growth and sometimes kills reefs.

One example of a vital marine fish is the Hawaiian cleaner wrasse. Hawaii is one of the most popular places for aquarium fish extraction, and the cleaner wrasse is a very commonly extracted species. But the cleaner wrasse serves an important function in the ecosystem: it “cleans” bigger fish, getting rid of dead skin, impurities, and particles to prevent infection and keep big fish healthy. And if we know anything about the way the marine ecosystem works, it’s important to keep the big fish healthy and happy. That can’t happen without enough little fish around. In captivity, the Hawaiian cleaner wrasse starves within 30 days because a small tank never provides enough big fish for it to clean.

A colorful Hawaiian cleaner wrasse cleans a puffer fish; From Wikimedia Commons

Why is demand for saltwater aquarium fish so high? Part of it is definitely the “exotic animal” effect, but there’s several other factors. Because reef fish don’t belong in and are not suited for a small glass tank, and the transportation from the ocean to their final destination in a home aquarium is so arduous, nine fish die for every one that actually ends up in an aquarium. So not only are people demanding a lot of fish – a lot of fish are dying that don’t need to. Extracting aquarium fish is also very lucrative – fish that are meant for food usually sell at $3 per pound, but aquarium fish sell for $248 per pound. This is very attractive, understandable, to subsistence fishermen and -women that live in places like Indonesia that are blessed with a rich diversity of fish species. The problem, then, is that many aquarium fish extractions go unreported, so the numbers are likely much higher than publicized.

How are reef fish actually extracted from the ecosystem? I know when I was snorkeling and diving in these reefs, I wouldn’t have been able to catch one with my bare hands even if I wanted to because they move so fast. One highly effective and highly dangerous way that aquarium fish are caught is through the use of cyanide. Cyanide is an extremely toxic chemical that was used in the first chemical weapons in World War I. In humans, cyanide poisoning can result in nausea, difficulty breathing, seizures, cardiac arrest, and even death.

On reefs, cyanide is squirted into a patch of coral and it stuns the fish that are living there, causing “severe gasping, followed by loss of balance and a complete loss of all respiratory activity”. This instantly kills some of the fish, but the ones that hang onto life float up and out of the coral, unable to do anything as they are scooped up and shipped off to live in someone’s aquarium. But cyanide doesn’t just affect the fish – for every live fish that is harvested, one square yard of coral is destroyed. Cyanide can cause coral bleaching, impact the coral’s biology, and sometimes kill coral. Use of cyanide on reefs is illegal in many parts of the world, but it is still used so frequently because it is not enforced very well.

So what can you do?

  1. Before you buy an aquarium for your home or business, consider purchasing a freshwater aquarium instead of a marine aquarium. Or, think about some other forms of decoration or other types of pets to purchase.
  2. Download the “Tank Watch” app, which gives a pretty good sense of which species can be bred in captivity, and which are usually extracted from the wild.
  3. Learn more about the issue through organizations like Sea Shepherd Conservation Society and tell your friends about the issue!