Giant Trevally Research on the Great Barrier Reef

Giant Trevally Research on the Great Barrier Reef

 

By: Matt Yamashita / IG account: @hawaii_reef_fishing

 I recently traveled from Hawaii to Australia to assist with a research project along the remote northernmost stretch of the Great Barrier Reef. The scientific study is led by Dr. John Keoni Kauwe, a longtime friend and fellow angler. Keoni and his team are mapping the genome of the giant trevally (GT) or Caranx ignobilis, also known as giant kingfish or ulua here in Hawaii. It is a widely dispersed apex reef predator, and a prized sportfish targeted throughout tropical and subtropical regions in the Indian and Pacific Oceans. 

I got involved with the project over 5 years ago when Keoni asked me to assist with gathering local DNA samples for the early rounds of his research project. I have been targeting GT here in Hawaii since the early 2000's using spinning gear for topwater and vertical jigging. We delivered the DNA samples successfully, but only with some effort.

Many people need to realize how badly Hawaii's reef ecosystems have been degraded due to decades of overfishing, intensive development, and the introduction of highly aggressive invasive species. Fishing today is not what our grandparents described from their time. I have pictures from the 1950s of my great-grandmother (a well-known angler in her day) with absolute hauls of various species of fish at sizes that you rarely see today. My father also tells me stories from his childhood about filling up 100lb sacks with smaller GTs in less than an hour of trolling with my grandfather.

Today, it's a different story. While 100lb+ GT can still be caught, it is not common. Even catching one over 10 lbs can be something a Hawaii angler might spend years trying to achieve. And filling a 100lb sack or a 100-quart cooler full of smaller GT in an hour is impossible today.

Is my own family responsible for overfishing in the mid-1900's? Yes. Did that generation know any better? Probably not. Do we know better today? Absolutely. Can we do something about it? I sure hope so.

It is believed that Hawaii's reefs were once similarly as healthy and abundant as those of Australia's Great Barrier Reef. Considering this, I was excited and curious to experience this remote and pristine marine ecosystem. But it was challenging getting there. It took four flights, two full days, and a long, bumpy drive through the dusty outback before we arrived at the northernmost shores of North Queensland, only to spend another 4 hours steaming out to the outer edges of the reef.

But it sure was worth it. I have never seen a marine ecosystem so rich and full of diversity. While we targeted GT for the genetic study, we also caught a wide range of other predatory species, many of which I had never even heard of. Using all barbless hooks and tight drags, along with highly skilled boat captains, we were able to land and release our fish healthy.

The charter company, East Coast Angling, did a fantastic job hosting us aboard their 60' mothership for the week. We fished all day for six days straight on three 23' center consoles and covered hundreds of miles of untouched waters. As an angler, it was a dream come true. Did our muscles ache after the first couple of days? Absolutely. Did we feel the pain once the day started? Not at all. We were energized with a sense of adventure, purpose, and gratitude.

         

As a new member of the Striker Pro team, I was also stoked to put my Striker UPF clothing to the test. Striker gloves, hats, gators, and hoodies kept me comfortable and protected on the blazing-hot, calm days and the stormy, wet days. I am a person who must believe in something to stand behind it, and this trip sealed the deal for me with Striker. 

 The trip was a complete success in gathering the genetic samples needed for the study. However, I have conflicting thoughts about returning home from Australia's Great Barrier Reef. I feel a sense of loss about the degradation of Hawaii's marine ecosystem that has occurred since my grandparents fished these waters. But I am also filled with appreciation and wonder at seeing how abundant and resilient nature can be in the more remote parts of the planet. 

Hopefully, the genetic research we are assisting with will help paint a clearer picture of how our reef systems work and what it takes to find the right balance where fish populations can thrive. At the same time, generations of future anglers can also enjoy the bounty of the sea and continue to feed their families through fishing, a tradition as old as time that fosters a deep connection between every angler on this planet. But we must also contemplate our individual role in maintaining the health of the resources that allow us to enjoy this cherished pastime. Harvesting only what we need to eat fresh, using barbless hooks, and releasing bigger fish to maximize spawning yields are good practices to consider.

I want to acknowledge and thank Dr. Keoni Kauwe for organizing this special expedition, as well as the members of our angling team who worked hard to deliver the needed research samples: Keala Kauwe, Josiah Ching, Nate Tsao, and Sai Kauwe.

For more info about the genetic study, visit here: https://pmc.ncbi.nlm.nih.gov/articles/PMC9694125/


Leave a comment

Please note, comments must be approved before they are published

This site is protected by hCaptcha and the hCaptcha Privacy Policy and Terms of Service apply.