I visited the Seattle Aquarium yesterday and passed thru the underwater tank at feeding time. For those of you who have never been there, they have a huge underwater viewing area into a tank filled with many different types of Puget Sound fish - lots of salmon, halibut, rock cod, sturgeon, etc. At 1:30pm everyday, a couple divers jump into the tank with bags of dead herring, shrimp and squid. They disperse the food into the water and the fish go crazy...

It was facsinating to watch the salmon feed. They would only eat if they were swimming up thru the cloud of food. They didn't eat on the way down nor did they eat when they were swimming horizontally. They would swoop up thru the food, turn away from the food, dive down and swoop up again. Even if a piece of food was right in front of them, they wouldn't eat it unless they were swimming up (vertically).

Does this mean that they rely more on sight than smell or sound?

It certainly supports the notion that the feeding salmon will be under a bait ball.

Charlie Whites videos show how they hit very well. They come through a bait ball and stun herring etc then turn around and feed on the stunned or take advantage of someone elses work. I have heard of some hatchery studies that show hatchery fish feeding contrary to the wild fish. All the Hatchery fish food is presented from the top so what you see at the SA makes sense as they are hand reared. I think you will see smoe different behavior from wild fish.

CD

Herring are most vulnerable to attack from below. The salmon know this because they are too. And that's why predatory fish like to attack from below.

I too have been fascinated while observing this activity at the aquarium. Every now and then I have seen it in the wild as well. I have watched as big king salmon drove bait into shallow water and the kelp and then took turns coming up thru the bait sometimes cartwheeling completely out of the water. Awesome!

But there is an important behavioral distinction between salmon in the wild and the aquarium, where the bait is dead and it only comes at certain scheduled times. In the aquarium it is has to be every salmon for himself. In the wild, salmon will often work as a unit dividing duties up between them like a pack of wolves. While attackers run up through the bait reflexively attacking anything that gets in their way they are usually supported by others who are herding the bait. Meanwhile these "herders" hang out to opportunistically pick up the falling wounded by snapping them up from the fringes and from below. You won't usually see this activity in the aquarium because the bait is not defensive, it is dead and is available only at certain times.

My personal experience tells me that when fishing for feeders, it is far more likely to catch one of these herders on the periphery of the bait then it is to hook an attacker in the midst of the bait. But one thing is for sure though, predatory fish, like salmon and steelhead, just can't resist a falling bait. And this behaviorI have witnessed time and again in rivers as well as the salt.

Here's to big bait balls.