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Mill Brook Preserve South, Westbrook

Updated: Feb 17

The alewives have arrived. Booyah!

Mill Brook hosts the largest fish migration from Casco Bay to Highland Lake, where the fish spawn each year, starting around this time (late May to early June). The best local trail for viewing Alewives is the Mill Brook Preserve. There are several trailheads for this secluded, peaceful trail...which truly tops my list of favorites.

I've shared the Perry Court trailhead details with you, so today we will talk about the Mill Brook Preserve South trailhead. Located at the northeast corner of the parking lot for Millbrook Estates (Route 302, left onto East Bridge Street, right onto Dolley Road), this trailhead is only 10 minutes from Portland. The address is 300 E. Bridge Street, Westbrook and you will find 4-5 parking spots designated for this trail near the trailhead kiosk.

As you start out, you may see horses on your right from the stables nearby. Continue onto the trail to this very fun curved bridge.

This is a 1.2 mile lollipop loop, which means that the initial short path will lead to a loop trail. Psst...make sure to tell your kids. They'll get all kinds of Candyland visions in their heads and it will just keep them going. A child's imagination is a powerful thing.

When you arrive at the fork in the road, you've reached the end of the lollipop stick and are starting the loop. We suggest you go right at this part, or counterclockwise around the loop, which will lead you to our Seek'em...and then some alewives (fingers crossed).

Shortly before you get to a sign for the .1 mile spur trail that leads down to Mill Brook, you will spot this giant tree on your left.

I guarantee your kids will climb right into it. Explore the tree, then continue on until you've reached the spur trail on your right. The signs are small, so be on the lookout!

Take the short spur all the way to the serene, clear waters of the Mill Brook. I had a whole gaggle of kids with me on this trip, plus my mom, so it was an adventure. Of course most of the kids ended up swimming and it was a muddy ride home (always), but watching these kids explore the river was pure magic.

We also happened to run into some other families on their way down to the brook, who follow our weekly trail posts and found the Seek'em by chance. More magic to add to our day!

Full disclosure, we did not find a single alewife here yesterday, but I did see hundreds of them this past Sunday when I went to the Perry Court Trailhead with my family. We found all of the alewives piled up at Goldilocks Falls...less than a mile along this trail, if you travel counterclockwise. For a chance to find some alewives, try Mill Brook South. Or, you could take the safe choice and head for Goldilocks Falls along the Perry Court Trailhead side of things. Here's a picture of the falls and fish.

I should mention, that Goldilocks Falls is roped off to protect the migrating fish, so you can't actually go in the water there. If you prefer to get your feet wet, head for Mill Brook South.

I will leave you with some facts about alewives that we learned at a recent alewife immersive with my friend Courtney of Wild Migration.

  1. Alewives reach reproductive maturity at 3-4 years old, and only then migrate to fresh waterways.

  2. Females deposit 60,000 - 100,000 eggs; only 1% of eggs survive.

  3. Eggs are .05 inches in diameter, pinkish in color, deposited on gravel or submerged vegetation.

  4. Incubation lasts 3-6 days at temps of 55-60 degrees.

  5. There are 39 streams & rivers in Maine that have harvesting rights.

  6. Indigenous populations smoked alewives.

  7. Alewives are currently a main source of spring lobster bait.

  8. Predators include nearly everything from bass to ospreys, raccoons and salmon.

  9. Threats to the alewife population include obstructions to spawning habitats, such as dams.

  10. The alewife diet is zooplankton.

And the most fun fact: Alewives are one of 12 species of fish in Maine that are anadromous. Say that three times fast.

Anadromous means that they spend part of their lives in freshwater and part of their lives in the sea. What a life...a long struggle upstream, avoiding predators and dams the whole way. And the "lucky" ones who survive, get to do the trip all over again the following year! See how easy we humans have it? We just get to play in the brook and wave to the pretty fish. Life truly is good.


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