In the Pink

Pink Salmon | Oncorhynchus gorbuscha
Pink Salmon | Oncorhynchus gorbuscha

One of the sure signs of the season is the return of the fall salmon runs to the east side of Vancouver Island. Puntledge Park in Courtenay, BC is an excellent place to witness the phenomena of salmon returning to their birth stream to spawn

If you have experienced a salmon spawn before you know that it is a total sensory experience – the smell of the dying spawned out salmon, the raucous calls of gulls, ravens, and crows, the sight and sound of a salmon fighting its way up through the shallow riffles, the feel (if you are so inclined) of a dead fish on the edge of the stream, and the taste … well, best leave that one out of it!

A reminder that if you are watching salmon spawning please keep your dog and children out of the river. Watch but don’t interfere. The fish have a very important job to do and don’t have the energy to waste on anything else. Move slowly on the edges of the stream or spawning channel and avoid startling or harassing the fish.

Pink Salmon | Oncorhynchus gorbuscha
Pink Salmon | Oncorhynchus gorbuscha

At this time of year pink salmon (Oncorhynchus gorbuscha) are in the Puntledge River and side spawning channels. The pink salmon is also appropriately know as the humpback salmon or humpie. During breeding, males change dramatically. The jaw develops a pronounced hook and a hump (hence the name) in front of the dorsal fin. Note the blotchy yellowish-gray sides with darker colouration along the back. The belly is a dirty white and oval spots are noticeable on the tail.

Pink salmon have a short life cycle. 1500 – 1900 eggs are laid in gravel redds in the fall by each female spawning salmon. After emerging from the gravel in the spring young fry make their way immediately to estuarine and near shore habitat where they spend anywhere from a few days to several months before moving to open ocean. The pink colour of their flesh comes from the krill which is a major part of the diet of the adult fish. Two years after the eggs were laid the adult pink salmon return to their home streams to repeat the cycle and die.

For the naturalist, this part of the cycle is very interesting. One gets the opportunity to see salmon up close and witness the process that begins the next generation of fish. In addition, the connections between salmon and the forest ecosystem become clear as one examines the return of the fish to forest. I was fortunate to discover this dynamic process in action. A warning to squeamish readers that while the next couple of images are very interesting they may be disturbing to some – read on if you’re curious!

Smaller decomposers are hard at work even before the larger scavengers like birds and mammals begin to play their role in breaking the fish down. I was lucky enough to stumble upon a fish completely covered with fly larva – though slightly disgusting in appearance it was also fascinating.

Fly Laying Eggs on Pink Salmon
Fly Laying Eggs on Pink Salmon
Fly Larvae on Pink Salmon
Fly Larvae on Pink Salmon

Additional information about the life cycle and characteristics of pink salmon can be found at the Fisheries and Oceans Canada web site. Jocie has also written a great article with more detail about pink salmon called A Good Year for Pinks.