Tuesday, July 31, 2012

Swan Lake Water Chestnut Removal

Last week the CRISP team went out to Swan Lake in Sullivan county to check out the status of the water chestnut infestation.  The infestation covered a substantial portion of the lake, about 120 acres out of 395.  The home owners association decided to use a chemical treatment after hand pulling failed to make a huge difference in the amount of water chestnuts.  They decided on a five year treatment plan, the first one took place in the summer of 2009.  The first treatment was a small area to test the effectiveness. It only took about 2 months for drastic changes to be seen. The CRISP team helped as much as they could during their brief visit to the area and managed to clear water surrounding the nearby park.  We want to encourage people to do what they can to manage breakouts like these before taking huge steps like chemical treatment.  However, sometimes its the most cost efficient and effective.  When I saw the lake I couldn't believe that less then 3 years ago it was swarming with water chestnut.  The residents of Swan Lake still have a long road ahead of them but they are optimistic and hope for a water chestnut free lake!
1 week after the first treatment
4 weeks after first treatment

Friday, July 6, 2012

Aquatic Invasive Training

On June 21st I went to a training on aquatic invasive species. The training was at a research station along the Delaware River, on the Pennsylvania border. The training was mainly for the summer staff, who help people who are boating on the river so that they can advise people to get their boats cleaned and to look for any invasives that may be on the boats. Unlike the reservoirs, there is no enforcement to make people clean their boats here.  The program was sponsored by CRISP as part of their boat stewards program.

The training was all day and we learned about 20-25 different invasive species and a few stories of species that are really bad such as the zebra mussel and didymo (AKA rock snot). There were so many invasives to learn and it was good perspective to see just how easily these organisms can spread and how hard they are to control. I also found it interesting (and shocking) that the introduction of invasives to an aquatic ecosystem has such a large effect on the diversity of native species.
Didymo is also one of the 10 priority species for CRISP that was presented at the training. It is a single celled organism that attaches to rocks on river bottoms and forms colonies that are dense mats.

 Colonies prohibit macroinvertibrates from living on the stream bottom. Since macroinvertibrates are such a large source of food in aquatic ecosystems and are important in breaking down organic matter, cycling nutrients didymo can disrupt the entire stream habitat. Here is a great video that shows just how much rock snot can spread from a single cell.

 One of the other aquatic species we learned about that are on the priority list for CRIP’S are Water Chestnut and Eurasian water milfoil. Water chestnut floats on top of the water like a lily pad and lowers the dissolved oxygen levels below what is needed to support a healthy aquatic ecosystem.  It can be identified by its thorny, black seeds.