Thursday, December 20, 2007

False Killer Whales Gang Hunting Lone Yellowfin Tuna

Continued from the previous post: Tasty Kona Kampachi of Kona Blue Water Farms...

After a couple of "buoy hopping," we arrived at one of the most productive FAD (Fish Aggregation Device) in Kona. We did some fishing and caught a pair of good yellowfin tunas, Thunnus albacares, for dinner. It was getting late and we were about 15 miles offshore and about to call it a day, when we noticed something going on in the water.

We first thought they were wild Indo-Pacific bottlenose dolphins, Tursiops aduncus, but as we got closer, we noticed their blacker, larger bodies and discovered they were something more rare and exciting: false killer whales, Pseudorca crassidens! Three of them!

As their latin name indicates, they share characteristics with more popular orca or killer whales, Orcinus orca. False killer whales are large marine mammals that grow to about 20 feet in length with a body shape somewhat like the killer whale, but more slender and without the distinctive black and white pattern. Like the orca, they are known to attack and kill other cetaceans such as dolphins and whales.

false killer whale, Pseudorca crassidens, blowing bubbles to startle a tuna hiding under the FAD (Fish Aggregation Device), off Kohala Coast, Big Island, Hawaii, USA, Pacific Ocean

False killer whales live around the Hawaiian Islands, but range widely. They are generally difficult to see up close, as they are rare to find in the first place and tend to shy away from boats. This time, they seemed preoccupied with something at the buoy. They appeared to be blowing bubbles toward the buoy again and again. It could be dangerous to photograph such "Killer Whales" up close, but it was a once in a lifetime opportunity for me to capture the moment if they allowed me to get close by.

The condition was very difficult to photograph them underwater as the ocean current was ripping and the sun was setting (getting dark). Besides I didn't want to disrupt their activity whatever they were doing.

It turned out the whales were trying to hunt a lone yellowfin tuna, Thunnus albacares, which was trapped under the buoy, using the buoy as a shield against the whales! What a smart fish!

A lone yellowfin tuna, Thunnus albacares, using FAD (Fish Aggregation Device) as a shield to dodge relentless attacks by its predators, false killer whales, Pseudorca crassidens, note rake marks left by the whales, off Kohala Coast, Big Island, Hawaii, USA, Pacific Ocean

I was kicking hard and trying to stay parallel with the buoy and whales in the strong current. I was barely able to keep myself positioned far enough from the buoy not to affect the activity of the animals, but close enough to watch and photograph this rare event. The false killer whales occasionally looked straight at me, but they seemed unconcerned about my presence. Apparently the tuna looked a lot more appetizing to them than I did.

false killer whales, Pseudorca crassidens, hunting for a lone yellowfin Tuna, Thunnus albacares, which is taking refuge under the FAD (Fish Aggregation Device), off Kohala Coast, Big Island, Hawaii, USA, Pacific Ocean

As the whales continued to focus on the tuna, they blew big bubbles underwater with a loud noise. It seemed like they were trying to startle the tuna away from the buoy and snatch it as it tried to escape.

Two relatively smaller whales tried this technique again and again, but at the last moment, the tuna was able to swim to the other side of the buoy, escaping the sharp teeth of killer whales. As this behavior was kept going on, the largest false killer whale of about 19 feet rushed into the scene from nowhere. The big one swam right under my legs and joined the rest of the whales.

Now three bubble blowing whales with open mouths ganged up on this lone poor, frightened tuna. Can you imagine if you were that tuna dodging these huge black monsters?

three false killer whales, Pseudorca crassidens, ganging up on a lone yellowfin Tuna, Thunnus albacares, which is taking refuge under the FAD (Fish Aggregation Device), off Kohala Coast, Big Island, Hawaii, USA, Pacific Ocean

Three whales persistently attacked the tuna but only in vain. After maybe an hour or so, the false killer whales finally gave up on the idea of eating the tuna, and faded into the dark blue one by one. Yes, the tuna prevailed and went on to live another day!

To be continued to: Silky Gold Silky Shark...


  1. The FKWs are hunting a yellowfin tuna under the FAD. It does not look like a bigeye tuna which have a more robust body shape and much longer pectoral fins at that size.

  2. Thanks for telling me that. Sometimes it's very hard to identify the two species. I corrected the ID.

    On the other day, I've got an opportunity to compare the two side by side. Please see this post: Shibi - Yellowfin Tuna or Bigeye Tuna?