Chuck #8

The alewife Chuck is named after Dr. Chuck Hopkinson of the Marine Biological Lab and Plum Island Ecosystem Long Term Ecological Research. Dr. Hopkinson provided us with field equipment (an electroshocker) and a place to stay while we were working in the field, at the Marshview House. Chuck (the fish) was captured in the Ipswich Mills Dam box trap on April 23 and released there after tagging. He was last seen by the stationary receiver at Site 1, perhaps headed toward the Plum Island Sound, on May 3.

April 23, 7:00 pm: Chuck is captured in the box trap near Site 2 (Ipswich Mills Dam). After being tagged, he was released at the trap.

April 24, 7:54 am: Chuck has moved upstream to Site 3, a broad and slow moving area of the river. He remains in range of this receiver for about 25 minutes.

April 24, 1:18 pm: Chuck keeps swimming upstream, reaching Site 4 in the early afternoon.

April 24, 3:34 pm: Chuck reaches the receiver at Site 5 just about 2 hours after leaving Site 4, and is heard moving in and out tof the range of this receiver over the next few days; the last time Chuck is heard here is at 12:03 am on April 27. After this he begins to swim downstream.

April 27, 8:46 pm: Moving quickly, Chuck swims past the Site 4 receiver in just a few minutes.

April 28, 5:48 am: Chuck reaches the broader area of the river again and slows down slightly. He remains in this area of the river for a full day.

April 29, 5: 49 am: Chuck arrives to Site 2, near the Ipswich Mills Dam. He remains within range of this receiver for an hour, then turns to head back upstream.

April 29, 11:41 am: In a few hours, Chuck reaches Site 3 again, and swims in and out of the range of this receiver for several hours, last  heard at nearly 7:30 that night.

April 29, 8:18 pm: Chuck reaches the Ipswich Mills Dam at Site 2, and remains in range for about 2 hours.

April 30, 7:19 am: Chuck arrives upstream to Site 3 in the morning, and spends a half hour in range of the receiver. He then is out of range and not heard until 7:53 the following day, on May 1; at this point he stays in range for three hours before moving downstream.

May 1, 11:54 am: Chuck makes a reappearance at Site 2, but doesn't stay long, and is last heard there at 12:01 pm.

May 2, 10:37 am: After a night out of range of the receivers, Chuck arrives in the morning upstream at Site 3. Until the next day, Chuck is heard moving in and out of the range of this receiver. He departs to head downstream at 12:29 pm on May 3.

May 3, 8:15 pm: Chuck reaches the Ipswich Mills Dam (Site 2) and descends it, continuing to head downstream.

May 3, 8:54 pm: After passing the dam, Chuck winds his way through town and reaches the receiver at Site 1 in just about 15 minutes. He passes by the final receiver in our array at 8:57, and we do not hear him on a stationary receiver again.

What do you think about Chuck's back and forth movements at Sites 2 and 3? This area is a slow moving, pond-like habitat, which should be suitable fro river herring spawning. is Chuck searching for something, maybe other fish to spawn with, maybe the perfect substrate for spawning? Or is he just lost and indecisive? Why didn't Chuck keep swimming upstream past Site 5?