Week 3: One Set Down
- emilyvanvlack
- Jun 14, 2017
- 4 min read
June 5, Monday:
Luke and I started off the week with a concern for the project. Last week, in the Sherman area, we found a 14-16 inch long dead fish in about 4 ft of water. We had concerns that the fish might be a small grass carp due to the fact that we were picking up a signal in the area. It was also difficult to see the fish clearly due to its position in the water. Therefore, we worked with Larry Marsicano in order to extract the fish for examination. Once the fish had been removed from the water, it was easy to see that the fish was not a Triploid Grass Carp. We sent pictures of the fish's corpse to a state representative for the Department of Environmental Protection to confirm the identity of the fish. The fish turned out to be a White Sucker Fish, a type of fish that looks incredibly similar to a Grass Carp. While we were very glad that the dead fish did not turn out to be one of our carp, it was necessary to take a closer look to make certain. As we continue our research, we need to consider that some of the carp could have passed away over the winter, or lost their radio tags. This scare with the dead fish serves as a reminder as to why it is so important to prove that all the fish are alive and moving in the lake to collect accurate data for the Triploid Grass Carp program.
June 8, Thursday:
A beautiful day in Sherman! Luke, Dr. Pinou, and I set out to collect data on the Sherman Arm of the lake. We found a total of 11 fish on the lake in the Sherman Arm. This data was exceptionally positive due to the fact that we found three fish in the cove near Sail Harbor where the Town of New Fairfield wanted to add chemicals to the lake to reduce the amount of milfoil. The fact that we found these three fish in this cove suggests not only that the fish are doing their intended job, but that adding the chemicals to the lake could have had serious implications to the carp program. Therefore, we are extremely glad that the town of New Fairfield voted against the addition of chemicals to Candlewood Lake.
Aside from collecting a large amount of positive data today, we reevaluated our radio telemetry technology. Previously, we had issues narrowing down the locations of the carp just by listening to the frequency of our receiver. As of today, we decided to use the RF Gain as a measure of fish closeness. Gain is how well the antenna converts input power into radio waves headed in a specified direction. Therefore, we can better determine the precise location of a fish and listen for movement.
Special thanks to Len and Phyllis for taking us out on their boat!
June 9, Friday:
Today was spent out in the field sampling both the center of the lake, and the New Milford arm. We had another successful day of sampling in terms of finding fish. We picked up the signals of 13 individual carp today. In addition, we saw more positive correlation between the carp and Milfoil beds today, Our boat captain this week, Bob, had a fish finder on his boat. While not so much helpful in terms of locating the carp, we were able to see areas where milfoil was present in extremely high concentration even when the plants were not yet visible from the surface. In the lower portion of the New Milford Arm, we came across a huge Milfoil bed where the plants were only 3ft below the surface of the water. The bed was visible from the surface as well. Here, we found three of the carp. Their signals were extremely strong, and using the Gain bar comparison, we were able to determine for sure that the fish were located within the large Milfoil bed. This was very positive to see, as we hope that the carp will remain within the larger Milfoil beds to feed.
In regards to the Milfoil beds this year, we know that thus far they are smaller than last year. This is likely a result of the annual draw down in addition to the below average temperatures of May and June. Areas that were cleaned out by divers or the draw down have not had the chance to completely regrow yet due to the cooler temperatures of the lake. We ran into the state representatives for aquatic invasives while sampling today, and they told us that the Milfoil plants were smaller than recorded last year, as by this time in June in 2016, some of the larger beds had already reached the surface of the water. This is important to consider as we track the carp, as it could impact their locations. Some of the fish may be deeper and out of range of our receiver at this point in time as the Milfoil plants are smaller and located deeper underwater.
Today marked the completion of sampling the entire lake once. Therefore, we can start to compare the data we have collected this year to the positions of the fish in 2016. We have also seen the majority of the 50 tagged carp during our first round of sampling. This is very positive news for the carp program as we continue to sample the lake this summer. We hope to collect data from the entire lake twice more before the 4th of July weekend. We have hypothesized that the large amounts of boat and recreation activity from the 4th of July onward will scatter the fish from their current locations, therefore giving us non-disputable proof that the fish are indeed moving.
Special thanks to Bob for taking us out on his boat for sampling today!
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