May and early June are a time of great events in an Atlantic salmon river. Smolt and kelts are obeying their biological clocks that urge them to return to sea, and in the rivers the youngest generation of fry are finding a first feed. For ASF’s research staff it means days at a time in the field, testing and deploying monitoring equipment in the rivers flowing into the Gulf of St. Lawrence and the Bay of Fundy.
Below is a narrative from Graham Chafe of ASF’s Research Department.
Graham Chafe is a member of ASF’s Research Staff. He describes some of their recent field activities, that often starts before dawn, and continued long hours, into the evening.
Towards the end of April, Mike Best and I deployed receivers on the Miramichi River and at the mouth of the bay in preparation for the acoustic transmitters we would be implanting in the salmon. The weather was still cold and the crew, along with Alex Parker from the Miramichi Salmon Association, had to contend with ice on the bay. The receivers were placed as far up the Northwest branch as Cassilis and the Main Southwest to Millerton – a long cold, cold day but with a lot done.
We were again on the water in early May, this time deploying gear on the Baie des Chaleurs. With the help of an Anse-Bleu lobster boat and crew, 28 receivers were deployed in a line across the bay.
Eighteen of these receivers were the standard rig with an anchor, line and buoy and the receiver about six meters down. The other ten receivers were on something called “acoustic releases”. These are rigs that keep the receiver on the bottom with an eighty kilogram anchor. The receiver is about six meters above the bottom, kept somewhat vertical by a buoy providing an upward
force. The acoustic release is an associated piece of equipment that can be communicated with from the surface using a hydrophone. When we want to retrieve the receivers, we send a coded signal through the water and the unit disengages from the anchor. The receiver and the release itself are taken to the surface by the buoy, collected and are readied for future use. This useful technology allows us to deploy gear without buoys and lines interfering with fishing and shipping activities in the area.
Kelts on the Miramichi
On May 5 and 6 Research Director Jon Carr and I teamed up with the Miramichi Salmon Association and others to tag kelts on the Northwest Miramichi at Red Bank. Volunteer anglers spent two days on the river catching kelts for us to tag with both acoustic tags, those that are recorded by the receivers, and Pop-up Archival Satellite tags.
The satellite tags collect depth, temperature and light information to provide a profile of where the fish have been and what kinds of environments they have passed through. The light information is used, along with an accurate internal clock, to calculate latitude and longitude in a manner similar to that used by sailors in the days before electronics.
These tags will pop off the fish if the fish dies or, if the fish remains alive, at a pre-programmed date at the end of the summer. It will float to the surface and transmit the data to ARGOS satellites. ASF staff can then download this data from their offices. It is the second year we have used this exciting technology and this will add to our understanding of the movements of adult salmon in the sea.
Thanks go out to all the anglers and volunteers who helped out with this project. We even had a visit from the Miramichi Valley High School Environmental Science class. They came out to have a look at our project and throw a few lines in the water.
This week is another busy one.
Steve Tinker is up at Rocky Brook on the Main Southwest Miramichi tagging smolts to be tracked through to the Strait of Belle Isle. The implanting of the transmitters in Northwest Miramichi smolts was just completed on the weekend and later this week Restigouche River smolt will become the focus of attention.
This week Mike Best is all over southwest New Brunswick installing temperature loggers, wading into sites along the tributaries of the Magaguadavic and other local rivers. This is a yearly activity that helps to monitor long-term changes in these watersheds.
Finally, the bypass – a downstream passage and collection facility in the hydro dam in St. George on the Magaguadavic River – is in its second week of operation. ASF staff will be monitoring it to count smolts and adults leaving the river. Many of the smolts we are counting this year were released as unfed fry in years past.
– Graham Chafe, ASF Research Staff