We are seeking volunteers to help out at the Rotary Fish Traps (smolt wheels) on the Nashwaak River. The time commitment is a ½ day, weekend morning and it is a really interesting experience.
Below is a list of the dates for which volunteers are needed. If you are interested, please e-mail NWAI board member Peter Salonius to let him know on which dates you might be available.
If you volunteer please share your photos by social media or email them to the NWAI office
NOTE: You may not be needed on the day you have chosen if the operation is not taking place due to high water or lack of fish in the days previous. You must wear a personal flotation device / life jacket and waterproof boots. Dress appropriately for the weather.
The Department of Fisheries and Oceans (DFO) technician who will be on duty for your morning will contact you by phone a day or so before to set a time and place to meet. The tech can often pick you up at your residence on the way out to the smolt wheels that are just downstream from Durham Bridge, and drop you back at your residence when the work is completed.
The wheel(s) look like cement mixers with the big end facing upstream — the current makes the wheel rotate and downstream and migrating fish are gently directed by the wheel’s rotation into a holding well at the downstream end of the unit.
You will travel by motorboat upriver to the smolt wheel that is guy-wired in the main current, and tie up the boat to the deck (like a floating dock). The tech will do most of the operation (clearing debris from the wheel and fish well, netting the fish and depositing them in buckets in the boat) but he or she will need you to tally the salmon smolts in groups of five, as well as marking down other species and their sizes on waterproof paper in a log book.
Once back on shore, some of the fish that have been retained in buckets will be anesthetized, measured, weighed and a scale sample will be removed for later analysis to determine how many years they have been in the river since hatching from the egg — here again you will be making entries in the log book and marking lengths and weights on sample envelopes into which the glass slides with the scales are deposited. A certain number of the fish will have a small part of their fleshy adipose fin removed / clipped off, which is an operation requiring both you and the tech. At the end of the morning, the marked fish will be taken several km upstream and placed back in the river.
What we learn from this process
The proportion of the fish that are recaptured on subsequent days will indicate how much (the proportion) of the total population is being captured by the wheel(s) so that the total number of juveniles migrating toward the ocean can be estimated at the end of the season. DFO operates an adult fish counting fence in the same location during the summer so that the numbers of salmon returning from the ocean can be compared to the smolt numbers that migrated to the ocean. This measure gives an indication of marine survival. The Nashwaak River is used as the INDEX river for all salmon streams downstream from the Mactaquac dam.
Planned dates for counts
Saturday, April 22
Sunday, April 23
Saturday, April 29
Sunday, April 30
Saturday, May 6
Sunday, May 7
Saturday, May 13
Sunday, May 14
Saturday, May 20
Sunday, May 21
MONDAY, May 22 (Victoria Day)
Saturday, May 27
Sunday, May 28