On Fish Feeding and the Jacks

The jacks or giant trevallies (Caranx ignobilis) are the beloved and iconic residents of the Miniloc house reef. Locally known as talakitok or mamsa, the jacks are a popular staple in Filipino cuisine. When I first sent my grandmother a photo of the fish, she immediately responded: “Talakitok! I eat that.”

Jacks are a type of marine fish distributed throughout Indo-Pacific tropical waters, from South Africa to Hawaii. They’re either black or silver-colored. While their color difference hasn’t been well researched, some studies point to aggression levels as a possible cause. They’re aggressive carnivores who eat almost everything, even their own kind – all they have to worry about are sharks and humans. Jacks can grow up to 1.7m long and weigh anywhere between 35 to 80 kilograms .

Commonly mistaken by guests for sharks, the jacks that visit the Miniloc pier are on the larger end of that range. Without fail, our family of around fifteen jacks will come back for breakfast every morning, remembering that they can grab a free meal here. Their breakfast is a mix of chopped raw squid and fish, courtesy of the Miniloc kitchen.

Fish feeding is generally frowned upon by many environmentalists because of it interferes with the fishes’ natural rhythms. The fish might become too dependent on humans for food and no longer be able to fend for themselves. Even worse, some people feed fish leftover bread and other processed foods, which are harmful to their digestive systems.

So why do we feed the jacks at Miniloc? The global giant trevally population is threatened due to overfishing. Jack catches have declined by 84% in the past century, and their numbers are further declining with the rise of commercial fishing methods (Animal Planet). When the jacks come to our reef, they are protected from the fishermen out in the open waters. Because the jacks in our reef are large, they’re potent breeders and are significant contributors to the rehabilitation of the jacks population.

We’re careful about how we feed them too. We only feed them fish and squid since these are normal parts of their diet. We never feed them more than 3 kilograms of raw seafood a day. Otherwise, they leave leftovers for the smaller fish in the reef, which we don’t want to start feeding too. They’re also territorial creatures that generally move alone, so it’s not natural for them to always be together.

That being said, we still serve jacks in the resort restaurants. We make sure that they are just the right size: no longer too small, but not yet big enough to be important breeders like ours.

Over the course of my stay at Miniloc, I’ve spent many mornings with the jacks, making sure they’re fed properly and that guests are well-informed about them. I’ve also swum with them; we offer guests the option to snorkel with these huge fish and see them up close. They won’t attack you, but they will be aggressive when they see food. It’s best to be mindful of the fish and the food being thrown during feeding times. Feeders should avoid throwing the food near snorkelers, and snorkelers should keep their distance from the food. The other morning, one accidentally bit my finger while it was trying to eat a chunk of squid that someone threw in the water!

Jacks are a vital part of our reef systems that we need to protect. So, next time you’re in Miniloc, maybe join in on swimming the jacks.

Gaby Coseteng is an intern for the environment department. She is a rising sophomore at Stanford University and is still undeclared. Gaby is passionate about nature conservation and climate change, and hopes to pursue a career in a related field. She enjoys kayaking, paddle-boarding, and snorkeling, especially since El Nido is so beautiful. Gaby is also a big fan of animals, but if she had to choose just one, her spirit animal would be a fur seal because they love to lay out in the sun and eat lots of fish. She’s really happy to be back home in the Philippines for the summer and to have the opportunity to learn more about the local environmental situation.