Following the Alewife

I've been going to Cape Cod since before I can remember. I spent every summer there growing up, which undoubtedly has had a major hand in shaping who and where I am today. Yet after all this time, it took me until today to witness one of the most dramatic and awe-inspiring feats of biology the Cape has to offer - the running of the alewife. In fact, it wasn't until I read John Hay's The Run a few years back that I even knew such a phenomenon was right in front of me all this time. Written in the 1950s, this book is, as most John Hay books are, a wonderful combination of natural history and philosophy. Since reading it, timing and distance have kept me from witnessing the run for myself, but about a month or so ago, I decided that I would make a concerted effort to see it this year. So with camera in hand, I headed out to the Cape over the weekend in hopes of catching the little critters in action.

Alewife, Alosa pseudoharengus, are anadromous fish of the shad family (Clupeidae) found along the eastern seaboard of North America from Newfoundland south to the Carolinas. Also known as herring (though not a "true" herring), alewife spend the majority of their life at sea, returning to freshwater ponds to spawn (as opposed to catadromous fish, such as Anguilla eels, which live primarily in fresh water, but spawn in the ocean). After spending a few years in the ocean, feeding and growing and surviving, the alewife gather just offshore in late-March to early-April. Shortly after this, on some cue (temperature? light? tides? moon phase? boredom?), the alewife start to migrate up the various tidal creeks to their spawning grounds, first in spits and spurts of individuals and then finally, by mid to late April, en masse. On the Cape there are a number of historic "herring runs", but one of the best known (and healthiest) is the Stony Brook run in Brewster. This is the run that John Hay wrote about and this is the run that I visited to follow the path the alewife take.

The Stony Brook run begins here at the mouth of Paine's Creek, a tidal stream that empties into Cape Cod Bay at Paine's Creek Beach:


Alewife that have successfully reached maturity and have made it to this point must now run a gauntlet to the spawning grounds. As they leave the ocean and travel upstream, they meander approximately a half mile through Paine's Creek into fresher and fresher water:






At this point, the creek goes through a culvert:


and crossed under route 6A:


Emerging on the other side, Paine's Creek becomes known as Stony Brook. The alewife must now swim another half a mile or so through Stony Brook and its surrounding marshes:



I am sure not every alewife that enters Paine's Creek makes it this far, but the journey to this point has been a cake walk compared to what comes next. As the alewife approach the fish ladder they have to contend with a nightmarish scene right out of Finding Nemo:





The only way any alewife can make it past that is if they come through in such numbers that the gulls can't possibly catch them all. Those that make it this far school together in shallow pools before continuing on:





After they've had a chance to rest a bit, individual alewife start to make the final push and head up the fish ladder. Here they make sprints up each cascade and are bashed and batted by the water and rocks. Many have to make several attempts as they are pushed back down or smack against the sides of the ladder. The energy it takes to do this must be enormous.





Next it's through another culvert, under Stony Brook Road, past the old mill, and up the last stretch of the brook:



Those that make it this far are rewarded with their ultimate destination, the quiet of Lower Mill Pond:


and the right to spawn before turning around and heading back through the gauntlet to the sea, where the open jaws of the season's first stripers will be waiting for them. It's not easy being an alewife.

This was quite a sight to see and I recommend that anyone on or near the Cape to go check it out. I don't know how long the alewife will be running or if I happened to catch them on a plentiful day, but the numbers were staggering. So many that even the air smelled fishy. However, there were people around who were talking about how much more plentiful the herring were when they were kids and telling stories of people pulling baskets full of fish out of the stream (no taking is allowed now). I don't think these were simply curmudgeony back-in-my-day sorts of stories - alewife numbers are down all along the coast and some historic runs no longer run. A variety of factors are seemingly at fault, such as poorly regulated fisheries, destruction or obstruction of spawning grounds, and polluted waterways.
(UPDATE: just found a video taken at a Harwich, MA herring run a couple of days ago showing the better-than-expected alewife numbers this year.)

In addition to the moratorium on the alewife fishery there are programs in place to help monitor and restore the fish populations. Hopefully enough can be done to ensure the continuation of this primeval rite of spring. As John Hay wrote close to a half-century ago, the running of the alewife has meaning beyond a bunch of fish racing up a stream:

...it seemed to announce that bud scales on shrubs and trees would start to crack and fall away to let the inner shoots unfold as leaves and feed on the sun. It said that flies and wasps and spiders would come out of winter biding and sleeping, that the song sparrows would begin to sing in the willows and viburnum bushes...There is something exciting and strange about the sudden appearance of new life in the spring, coming from another region, another climate...They recur; they are recognizable; and yet they bring in endless tides and vivid journeys

(For more info on alewives, check out this Audubon article and read John Hay's book)