This month customers of the Kennebunk, Kennebunkport, and Wells Water District (KKWWD) got some news about the upgrades and repairs to the fish ladder on Branch Brook in the Winter 2014 Newsletter. Chief Plant Operator Greg Pargellis provided a nice write-up on a really positive collaboration with the Wells Reserve to bring the fish ladder back on line.

This isn't the first time that the fish ladder has been in a KKWWD report. In the 1954 Trustees Report (see pg. 14), the Water District mentions plans to increase the height of the dam by 2 feet and to build a fish ladder which was ordered by the Maine Department of Fish and Game.

Seventy years later the fish ladder is back in operation.  This spring, we will be monitoring the fish ladder's performace, partly by using Passive Integrated Transponders (PIT tags). Brook trout and sea lamprey will be tagged below the dam and an array of antennas in the fish ladder will monitor how the fish use it.

We will also collaborate with Bates College to determine if brook trout have spent time feeding in the ocean (a behavior known as anadromy). Researchers at Bates will analyse fin clips for carbon or strontium isotopes that only exist in the ocean. Sea-run brook trout pick up these elements in their body tissue as they feed, so the marine isotopes act as a signal indicating where the fish has been.

To learn more about stable isotope analysis to study animal behavior check out this illuminating article in Nature.