Wednesday, 14 November 2012

Rainbows Instead of A Dam

We all know something about fish.  What always strikes me as funny is that we never ever see most fish that live around us. This is unfortunate, because there are so many neat fish in our neighbourhood.

One of prettiest fish in our area is the Rainbow Darter. You just have to look at them to see where they got their name. Interesting thing about Rainbow Darters:  males are brighter in colour than females — just like most birds are. (Males just like to show off, I guess).

So what are darters?  Darters are small fish and, in Ontario, there are about 10 different species. They are almost always found on or near the bottom. They swim for short distances in a hurry. They seem to just dart around. Some live in the great lakes in shallow waters and some choose deeper water. The Rainbow Darter likes streams. 

Darters are small fish.  Most of us would simply call them minnows if we didn’t look closely. They might get to about seven cm in length, but most are well under five cm — a child’s little finger in size.
The darters that live in rivers and fast flowing water can hold their position in the current. They have large and strong pectoral fins for their size. Think about where arms would be on a fish if fish had arms. Well, that’s where their pectoral fins are. They use these fins for strong, short bursts of speed, or to just hold onto the creek bottom.

Rainbow Darters feed on very small aquatic insects and invertebrates. Invertebrates are animals without backbones. Think of worms, crayfish and creepy crawlies. If they are really small, and like to live around small rocks in the water, then they just might be food for RainbowDarters.

Rainbow Darters are generally found throughout the Spencer Creek. If you find Rainbow Darters, then you know the water quality is pretty good, otherwise this fish species would not be living there. They don’t do well with pollution or heavy sediments in the water.

Today, the Rainbow Darter has a new home in the Spencer Creek, where the old Crooks’ Hollow Dam was. In 2012 the dam was removed for safety reasons and an innovative design project was undertaken to rehabilitate the section of the creek that used to be affected by the old dam. 
This rehabilitation project has had wonderful results within its first year. From land, the change in the habitat is easy to see. There are creek riffles, shallow spots and deep spots for the different fish to enjoy. Recently, Hamilton Conservation Authority ecologists monitoring the Spencer found Rainbow Darters in this new section of the creek. 

This is wonderful news. What better judge of how we are helping the environment than to be told by a small but interesting fish species that the water is of good quality and its flow is just right for a healthy stream.
If you haven’t visited the new trail and bridge by this restored section of the Spencer, you might like to make a trip to see how this section of the creek has been given a new chance at life.

Now, you are not likely to see Rainbow Darters; they are small and like to hide, but you will see the different sections of the new Spencer Creek with its currents flowing over and around rocks. 

You will also see where the water bubbles over structures and gets re-oxygenated.  The new vegetation communities are moving in toward the creek, providing shade and habitat for fish and other wildlife. 

The Rainbow Darter is just one species that has been advantaged by this new section of the Spencer. It is one of many.

Bruce Mackenzie 
HCA Manager of Operations & Customer Service

*Photo credits to Flint Rover Conservation Association, Environmental Almanac, and HCA* 


1 comment:

  1. Great Work HCA - Good to see the some active rehabilitation work on the watershed to help recover some of the impacts cause by dams. Hopefully other projects will be initiated as well.