Thursday, August 14, 2008

Bring Back the Don newsletter

I wrote an article about Riverdale Farm Ponds in the Fall 2008 issue of the Bring Back the Don Newsletter. It pretty much summarizes the work we do all summer and it contains pictures from this blog. Take a look.


While we were taking samples from the pond this week for the Benthic macroinvertebrates study, we were in the company of several black-crowned night herons. I've never seen so many at that spot, usually there are only one of two. And they were pretty close too. We tried not to disturb them but they were probably wondering what we were doing. However, I don't think they were interested in the macroinvertebrates insects, there was plenty of goldfish for them to feast on.

Monitoring water quality

Benthic macroinvertebrates

This week, we did the annual collection of benthic macroinvertebrates. They are animals found on the bottom of a water body that are large enough to be seen with the naked eye and lack a backbone and internal skeleton. They are relatively sedentary and widespread, with varying tolerances to changes in water and sediment quality.

As in previous years, we were joined by members of Citizens Environment Watch, an organization which provides education, equipment and support for community-based environmental monitoring and stewardship. The monitoring procedure that CEW developed enable volunteers to sample stream habitats for benthic macroinvertebrates. The procedure includes necessary information to collect, process and identify benthic macroinvertebrates found in southern Ontario watersheds.

Collecting samples in one of the Riverdale ponds

The sampling is performed using a D-net (so-called because it's in the shape of a D) which is placed firmly against the stream bottom. Afterwards, the D-net is emptied into a sieve over a bucket or large tray and stewards use squeeze bottles and water from the stream to rinse the net. Once this is done, it's time to look for the bugs and try to find them. Unfortunately, at Riverdale, there is so much mud that it's very difficult to see anything. We managed to find a few, including isopoda (sow bugs) which have a tolerance value of 8 or high tolerance to poor conditions.

We should soon have the results of our experiment and I will post them as soon as they come.

Tuesday, August 5, 2008

Massey/Goulding estate

Last week, the team went on an outing to the Massey/Goulding estate on Dawes Road north of the Danforth. It is part of the Taylor Massey Creek and the group Friends of the Don East has been maintaining the site. They basically removed all the Manitoba Maple and other non native trees from the area and planted native species so the area now offers a lot of diversity for birds and wildlife. We observed a lot of goldfinches there. However, even though the Manitoba Maples have been removed, there are still a lot of saplings and this kind of tree grows very fast so after our tour, we proceeded to remove those invasives. The size of the saplings is pretty impressive, especially when you only expect some small shrubs.

Some of the Manitoba Maples that we removed.

Water testing

I'm a bit behind with my posts but I'm now catching up. A couple of weeks ago, we tested the water in the ponds and the results were actually not bad, in spite of all appearances. The water in the ponds moves slower than other sites so factors such as water and soil odor, water appearance and dissolved oxygen showed poorer results. All the pictures in this post were taken at the Beechwood wetland site but the exact same test was done at Riverdale and the results were surprisingly similar.

The dissolved oxygen rating was poor

The phosphate level was fair.

Phosphorus is a nutrient that acts as a fertilizer for aquatic plants. When nutrient levels are high, excessive plant and algae growth creates water quality problems.

The ph level was 8 which is considered to be good.

The pH is a measurement of the activity of hydrogen ions in a water sample.