We are deeply saddened with the untimely death of Kevin Galvin earlier this year. Kevin was instrumental in setting up, coordinating, maintaining statistics, and providing colorful commentary both in person and in his blog re the Marstons Mills watershed herring counts each spring. He has left us with big shoes to fill. We're hoping to retrieve some of his background information and files at some point, but in the meantime the community at large knew Kevin would want to preserve and expand the data he started, so that we can all learn more about how best to preserve and protect our river herring. Please click here to review his old posts from past years - they are very informative and entertaining.
Three Bays (www.3bays.org) has stepped in to fill the void, by working to coordinate this year's herring count on the Marstons Mills River. I was a volunteer counter for the first time in 2011 after having moved full time to Cape Cod. Knowing that the herring were likely going to start an early migration, I volunteered to help Three Bays coordinate this effort. I'm no computer professional, like Kevin G, but can manage reasonably well around data. I'm hoping I can help to continue what he started in a meaningful way.
The data for all herring run counts from 2006-2011 are shown here.
Mother Nature has been playing games with us all season, to the point where we haven't really had a winter. It will be very interesting to see when the fish start running, and if last year's very small count was an anomaly, or is indicative of future trends. Since we started officially counting herring using the MA state protocol in 2006, the earliest the herring run has started was April 4th. We're pretty confident they'll be earlier than that this year.
Three Bays has a solid relationship with the Indian Ponds Association (www.indianponds.org), and there's a strong linkage to this project, since the river herring start in Prince Cove and travel through the Marstons Mills River to Middle Pond and Mystic Lake. Please see an explanation of the counting to date and the route the herring travel in the IPA's winter 2012 newsletter posted here.
We are interested in trying to better project when the herring will start their run. The alewives are known to begin their migration when the water temperatures reach nominally 51 F. We searched around for a nearby south coast real time temperature sensor with some history, to see if we could start to develop a correlation to the start of the run. The closest continuously recording temperature measurement we could access via NOAA data that had some history in the March/April time period was at the entrance to Eel Pond just west of Waquoit Bay in Falmouth. This entrance is a deepwater inlet, and should be a good indication of the coastal seawater temperatures as they mix with the bay. The red lines are 2010 data; blue lines are 2011 data, and the green line is 2012 to date as of this a.m. Vertical lines show the first day of the Marstons Mills river herring run for each year. (Click on graphs for full size view.)
There is also a sensor in Cotuit Bay, on the east side of the bay. This sensor does not have historical data prior to 2011 in the March / April time frame. The temperatures in Cotuit Bay very closely correlate to the Eel Pond inlet, albeit a couple of degrees warmer, since it is further from the ocean inlet.
In both cases, the sensors show variations in the temperatures, which reflect the impact of tides. The peak water temperatures this time of year occur at low tide, when the bays are the shallowest. The low daily water temperatures occur at high tide and reflect the colder incoming ocean water mixing with the warmer bay water.
In all cases, yesterday's warm water at both Cotuit Bay and Eel Pond well exceeds 51 F. In the last two years, the Marstons Mills river herring run started on the second day the peak temperature at Eel Pond exceeded 51 F.
So where are the herring now? Are they ready to go, or do they know something we don't know?
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