More Juvenile Trout for Our Bighill Creek and System

The first reveals of new generations of trout that have hatched in 2020 is a great time to boost ones optimism and look forward to the future of the fishery. Recently, I reviewed some of the video footage and photos of young trout that I have accumulated over the years. It is important to document and compile photo evidence of such things for future reference, like establishing a baseline. There is always a good chance that all of this natural aquatic life may disappear, but this is a fear that I hope will not come to pass.

It is like the old Joni Mitchell song lyrics; “You don’t know what you got, till it’s gone!”. That is one of the first environmental tunes that I recall from my youth.

These tiny trout seem to be in constant motion, even in the slightest current of flow. Their microscopic world is full of dangers and food for the young trout.

Only a small percentage of the eggs laid down to incubate, will eventually hatch. After a small number of trout fry emerge from their spawning beds, only a small number of those will survive to see their first year’s end. This is just the way nature works for wild trout. Trout are very environmentally sensitive and they are often considered “Canaries In A Cage”, as indicators of the condition of the water and their natural environment. Very vulnerable to pollution and loss of habitat.

The dark parr marks are typical on most salmonids. Some juvenile brook trout have smaller secondary spots that are located between the larger main parr marks on their sides.

The spring creek tributaries that allow for such an abundance of life, including the spawning, incubation and hatching of trout eggs, are very important to entire aquatic balance in the main-stem of the Bighill Creek. One of them has almost been total destroyed by a storm drain inflow, from a nearby development. I doubt if there is much hope for the future of Ranch House Spring Creek.

The tail of the small brook trout is quite different than what you see on mature trout. They rely on the broad power of the tail fin to propel them from danger.

When trout eggs hatch into trout larva, their tails and fins are under developed and it takes weeks for this transformation. During that period of time, the trout are relatively poor swimmers. The trout fry are just learning how to get about and over time the word quickly can be added to this statement. It takes time to develop muscles and sharpen their mobility. After a few weeks, when the trout become better at swimming, they will venture further away from their nursery habitats.

The large dark shadow often gives their position away, on the bottom substrate and rocks.

Something that you will notice in all of the photos of young trout that I show, the water is crystal clear, yet the environment is rich in nutrient and there is a constant food supply for young trout. Some years the trout egg hatch is high in number and there are lots of new young trout to photograph.

Most of the time, the small trout fry are revealed in low light conditions. Waiting for the sunlit photos can be spent observing trout that are hard to spot.

In all of the years that I have monitored the winter hatch of trout, I have never seen any sign of whirling disease. The pure spring creek ground water is most likely why the parasite has not yet made it up into the headwaters. Wild trout are especially vulnerable to whirling disease, in their first weeks of free swimming. The young trout have soft, undeveloped spinal cartilage. This makes them an easy victim of the parasite, often transmitted thru the water as spores.

Safety of cover habitat is usually close by to trout that are still only weeks in age. The crevices under rocks and woody debris make perfect hiding spots.

Juvenile Brook Trout on Ranch House Spring Creek

The Ranch House Spring Creek was once a spawning tributary to the Bighill Creek, but a new storm drain has destroyed what once was. The video below shows newly hatched trout in the creek, before it was changed forever.

The chart above shows the documented spawning survey results. There was no spawning in 2019, so the last year was 2018. The entire stream channel has been altered after only a few years time, since the storm drain was constructed on the creek.

The chart above shows a zero for the year 2014, in which there was no spawning on RH Spring Creek. The reason for this was that the creek was used as an outflow, while pumping down a nearby lake that season. The water quality was very poor and the trout sensed this and didn’t spawn that fall.

Leave a Reply

Your email address will not be published. Required fields are marked *

* Copy This Password *

* Type Or Paste Password Here *