Rainbow trout and spring cleaning
In addition to the many land and air species returning to this area after a winter nap or migration holiday, the rivers and streams are once again about to come alive. The rainbow trout are moving in, adorned with lateral blush mating stripes and getting reading to slip into their spawning beds.
Rainbow trout ( Oncorhynchus mykiss ) are widely distributed throughout this area, not only by their own free will, but also with the occasional help of others. For better or worse, this has allowed them to establish populations in naturally inaccessible areas beyond waterfalls, steep gradients and even into the alpine. (Note to those who have the notion of starting their own trout pond in a seemingly uninhabited natural pond: fish will displace or eliminate many of the naturally present species such as frogs and salamanders, which in turn will change population dynamics up through the food chain. It is also illegal.)
The springtime is the best time for checking out our local rainbow trout without having to try your luck with a fishing rod. They are slowly making their way into our local streams to play the game of procreation. Crabapple Creek runs under a Valley Trail bridge close to the snack bar at the 17th hole. Here is a great place to view the rainbows spawning without disturbing them. There is a fence built by volunteers that runs along the river to deter dogs from entering the creek and disturbing egg nests (redds) in the gravel that the female took such great care to build.
The eggs will lay in the gravel for up to seven weeks, but if the temperature is right it will be closer to four. The newly hatched alevin stay in the gravel and look like tiny fish with a giant bulbous belly. This belly is called a yolk sac and will be their source of food until it is completely absorbed. Then it is time to emerge into the open water as little fry. Some fry will move immediately to their lake of parental predetermined choice and others will stay in the stream as long as there is adequate flow, food and cool temperatures.
These fish, on average, will mature in three or four years to join the springtime spawning celebration. Unlike salmon species like Kokanee, these rainbows will not die after spawning, and will in fact be able to spawn every year successively. This is of course assuming that no unforeseen factors enter the equation.
There are many things that can be done to encourage the productivity of a rainbow trout population. Respect and protect vegetation in or around a stream as it provides shade for cooler temperatures, cover from predators and fallen insects for food. Leave logs, rocks and debris in the stream for shelter. Avoid walking in the stream or allowing your dog to, it disturbs fine sediments. The sediment suffocates insects, eggs and alevin by clogging their gills. This is also a good reason to sweep up and dispose of all the winter debris and sand, rather than sweep it directly into storm drains. Most of our storm drains lead directly to valley creeks, so this is also important when using chemicals on lawns and gardens.
And finally, if trying your luck with your fishing pole remember to follow all local fishing regulations.
Whistler Bird Walk, Saturday, May 31.
Meet at 7 a.m. (it's not that early!) at the bottom of Lorimer Road, by the entrance to the Catholic Church. Guided by fabulous and friendly locals like Nancy Ricker, Michael Thompson, Heather Baines, and Karl Ricker. Everyone welcome – novices especially! Bring binoculars and a field guide if you have them.
3rd Annual One Mile Lake Bird Walk in Pemberton, Saturday, June 14th
Meet at the parking lot at One Mile Lake (enter by the Welcome to Pemberton sign) at 8 a.m. Guided by five experts with the Breeding Bird Survey: Barry Janyk, Kevin Bell, Dave Aldcroft, Derrick Marven, and Geoge Clulow. These guys are exceptional birders who make it fun for experts and novices alike. Everyone welcome (bring binoculars and a field guide if you have them).
WEEKLY NATURE WALKS
Wednesday, May 28: Cancelled. See you next week.
Wednesday, June 4, 6:30. End of Lorimer by the Catholic Church. Join in celebrating Eco-week.
Written by: Veronica Sommerville