Photo of the Week: September 14, 2009

Hi Gang!

Last week I shared an image of a brown bear, the name given to grizzly bears that are found around the ocean, that I took during a recent trip to Alaska. That bear was “fishing” for salmon in a creek in Gravina Bay, a beautiful fjord in Prince William Sound. This week I thought I would like follow up on last week’s image by sharing an image of a pink salmon (Oncorhynchus gorbuscha), the type of salmon the bear was pursuing. I took the picture while lying flat on my stomach in less than one foot of water in an ice-cold, glacier-fed creek where pink salmon spawn. That is not exactly how I envisioned my “dive trip’ to Alaska, but I was grateful for the opportunity to photograph salmon. It was a first for me.

Pink salmon are also known by the names “humpback salmon” and “humpies” because of the pronounced protuberance, or “hump”, that develops on the backs of adult males before they spawn. Pink salmon are the smallest of the five species of salmon that occur in North America and that are collectively referred to as Pacific salmon. An average adult pink salmon reaches a length of 20 to 25 inches and weighs in the neighborhood of 3.5 to 4 pounds.

Interestingly, adult pink salmon that are returning from their eighteen month-to-two-year long ocean sojourn to spawn in costal waters are bright, steely blue on top and silver on the sides. They have a number of black spots on their back and tail. As the adults approach the streams where they spawn the bright appearance of the males dulls. Spawning males become black-to-brown above with a white belly, but some specimens show some bright colors at times. Females turn olive green with dusky bars located above a lightly hued body.

By the time the males enter the streams where they spawn they have developed their telltale body hump as well as “hooked jaws”. Spawning occurs between late June and the middle of October. Most pink salmon spawn within a few miles of the coast and many fish spawn in or near the mouth of streams. Shallow areas where running water breaks over beds of coarse gravel and small, cobble-sized rocks as well as the downstream ends of pools are the preferred spawning sites.

Females “dig” a depression in the bottom with their tail. This area serves as a nest called a redd. Females carry roughly 1,500 to 2,000 eggs. The eggs are released into the redd where they are quickly fertilized by one or more competing males. Once fertilized most of the eggs are covered with rocks by the female. This process is repeated a number of times until the female has deposited all of her eggs. You can see some uncovered pinkish eggs on the bottom in this week’s POTW.

Spawning signals the end of the life of a salmon as both the male and female will soon show obvious signs of deterioration, and they will die within a matter of days to a couple of weeks. While they are alive the salmon are heavily pursued by both black bears and brown bears. The bears only eat the skin and other parts of the salmon that contain the highest fat content.

The eggs are heavily preyed upon by gulls and other birds. Those salmon that do hatch head for open sea the following winter or spring. The fish mature in two years, and at that time they will return to the stream where they hatched in order to complete their life’s mission by spawning.

I took this week’s POTW with a Tokina 10-to-17 mm zoom lens set at a focal length of 15mm. Probably because they keep an eye out for bears the salmon are hard to get close to if you move. In fact, when lying in the creeks I tried not to move at all except to adjust my camera ever so slightly to compose my shot and to trip the shutter. Other than that, the technique was to find a place that looked good and be still. That’s easier said than done in the cold, running water!

There was no need to use a strobe because I was so shallow. I used a fast shutter speed, somewhere between 1/125^th and 1/350^th of a second depending on what the sun, clouds and rain were doing. It rained a lot during my trip, and I was constantly shooting with higher ISOs and slower shutter speeds than I wanted to when trying to photograph bears and other wildlife, but I was able to use ISO 200 and relatively fast shutter speeds when photographing the salmon.

While trying to capture this image I kept one eye in my viewfinder so I could frame the shot while trying to also keep a watchful eye out for the brown bears and black bears that fed at the creek. That, too, was definitely a first for me!

I hope you enjoy this week’s POTW, and I look forward to seeing you here next week!

Marty