300 years ago these fish were the same species.

These fish are alewife found in lakes and rivers of Connecticut. The larger of these fish comes from Bride Lake, the smaller pair was found in Rogers Lake. Pretty amazing difference right? 

Prior to development, these fish were quite literally the same species. These alewife live their lives migrating between rivers, lakes, and the ocean in this area. Prior to the arrival of humans, these fish lived part of their year out in the open sea and part in lakes. They would migrate upstream into lakes and feed on blooms of phytoplankton during the months when that food supply was available, turn around and head out to sea, feeding on other food supplies in the open ocean when the food supplies in the lakes became limited.

But, 300 years ago, settlers dammed the river that leads from Rogers lake to the ocean. The fish could no longer migrate downstream and any fish stuck in that lake could not reach the ocean.

The fish consumed virtually all the plankton they could feed on but that wasn’t enough to last the full year. As a consequence, most of the larger alewife in that system died off, but smaller ones were better-equipped to survive. On top of that, the fish switched food sources; smaller gilled fish capable of eating smaller types of plankton were able to flourish.

In only 300 years, the building of these dams created what are effectively completely new species of fish by changing their food supplies. These fish aren’t the only ones undergoing these changes; bluegill in these lakes have been found to show the same types of variation as well.


Image credit: Yale/ Post Lab

this is the newly paved bike path along the tracks to the alewife mbta station.  i haven’t been on it since these changes have taken place and i think it will be a perfect opportunity to try to take some pictures.  i really need to be pushing myself to photograph as often as i can.  this path was the first place that really inspired me; so much so that it practically got me into mica, being the dominant subject in my portfolio.

(this lovely image is not mine, but it is quite lovely.  clicking on the picture will bring you to the blog i found it on.)

So, the trout in the lake near my house feed voraciously on alewives in the morning. Until now the only thing that has accurately mimicked the alewives enough to fool the smart fish has been a SAMMY65 by LuckyCraft. Obviously though fly fishing with a lure like that is impossible. For two years I’ve been developing flies to try to match the walk the dog action and injured bait look of that amazing lure. FINALLY I AM CONFIDENT I ACHIEVED THIS! This fly is one i tied last year but with one huge improvement. I added a 3/16" brass bead to the inside of the tail. The foam in the front still allows the fly to float, however it now sits in the water vertically and pops up and walks with every strip of the fly line! I am so excited for april/may when I can actually put it up against a feeding brown!


Steve Vilnit from the DNR talking about Snakehead and why we should eat it at the Snakehead Dinner at Alewife Baltimore.