Thursday, March 26, 2009

Awaiting the herring


I am still awaiting the spring peepers. The north shore of Massachusetts has been hit with some unseasonably cold nights, last night bottomed out in the upper 20s. I still have hope that tomorrow's rain and forecast of near 50 F might bring the little frogs out. I'll keep you posted.

In the meantime my focus has turned away from blogs about motherhood, diapers and frogs and towards fish. Yes, fish. More specifically river herring, or alewife (Alosa pseudoharengus) and bluebacks (Alosa aestivalis), which return to our rivers here on the east coast starting in March. They swim upstream, spawn and then return to the ocean until, if they're lucky, next year when they do it all over again. Early sightings began weeks ago on the south coast and Cape Cod. The first herring ever seen in my local Ipswich River was on March 31st. So any day now. As soon as that water hits 10 degrees Celsius (50 F) it really gets going. I checked the other day: 6 C. We have a little bit to go.



Historically the Ipswich River had a herring run in the millions. These fish supported a food chain from herons to river otters to humans. There's evidence of seasonal Native American fish camps along the river and documentation of fish so thick you could net hundreds out in one swipe. Last year the river saw 130 fish migrate through the fish ladder to spawn upstream. One hundred and thirty.



Check out this graph from the Massachusetts Division of Fish and Wildlife:


So what happened? River herring have many enemies. Their decline started in the 1600s when colonists began installing dams along New England's waterways to run grist mills and eventually factories. These dams blocked the herring's spawning migration and the noticeable decline prompted a law passed way back in 1786 which required dam owners to install fish ladders allowing the fish to pass an otherwise impassable obstruction. These ladders help, but it's only part of the battle.

Off shore fisherman targeting Atlantic herring, a cousin of the river herring, also catch river herring as by-catch. River herring are tossed back, but the chances of surviving being hauled up in a net from a hundred feet down are pretty slim. Most of them become gull snacks.

If a river herring survives a fisherman's net, and can make it past a dam they also commonly face water shortages. Many towns draw their water supply out of local rivers but don't put it back in after the sewage is treated. Believe it or not rivers that should be running at 100 cubic feet per second in the summer actually run dry. This photo (http://www.crwa.org/projects/sustwater.html) is of our beautiful Ipswich River minus the "river". Even if the adult herring make it out before the river dries up there's no way the newly hatched fry can get out since they don't go back downstream until September. Fortunately some savvy folks at the IRWA have battled to stop this practice and we've had water year-round for the past two years, at least in our river....

So this year I'm keeping my fingers crossed for a number at least over 130. Why should I care? Well, river herring are an indication of a healthy river. And having a healthy river for my child to grow up next to, canoe on and hopefully even swim in someday sounds like a pretty good thing to me. Keep an eye out for me at the fish ladder waiting for the herring. If you stop by you might be lucky and see a herring or even one of the two thousand sea lamprey that flopped their way up it last year. That sight alone is worth the wait.

2 comments:

  1. Hey Kate,
    You commented on my blog, so I checked out yours. I like this herring post. I work for the Jones River Watershed Association and we are starting our herring count on 4/1. Jones River is in a similar state as the Ipswich (as are most). Next time you take a trip to the south shore to see Jess you should check us out!
    -Alex

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  2. Hi Ruth, thank you for your comment! It's nice to know people enjoy my little blog, I hope you do visit again! -kate

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