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Going Green Production of copepods, on which herring feed, is falling in the Gulf of Maine. went looking for answers. Te result was a paper pub- lished March 29 in the scien- tific journal, Marine Ecology Progress Series. "We're looking at abso- enormous lutely taken between September 1998 and Decem- ber 2010 in a West-East line from Portland, Maine, east to Yarmouth, Nova Scotia. Four of the eight wettest Phytoplankton fall I Gulf of Maine productivity plunges amid record rainfall, climate change BY LISA DUCHENE n Wilkinson's Basin, an area in the Gulf of Maine east of Boston, University of Maine marine scientist Jeffrey Runge is looking for a fat-rich copepod called Calanus finmarchicus. Her- ring eat these tiny animals, a type of zooplankton. Since herring are critical lobster bait — and a key for- age fish for Gulf of Maine fisheries — calanus are im- portant to the lobster market. Runge, a biological ocean- ographer based at the Gulf of Maine Research Institute, hopes to see huge numbers of calanus, which spends its winters in the depths of Wilkinson's Basin, feeding historically productive fish- ing areas like Jeffreys Ledge and Georges Bank. But he may instead find a drop. Tis spring, another scientist reported a five-fold plunge in the amount of Gulf of Maine phytoplank- ton in 2007, arguing it is a result of record rainfalls and climate change. Rather than a blip, the phytoplankton drop has been sustained. "A five-fold decrease is pretty important," says Runge. "[For] reductions like this that are sustained, [we've] got to wonder if that influences the system's car- rying capacity." If Runge's work shows a drop in calanus, it will be a sign that this plummet at the base of the food web is af- fecting other species. Phyto- plankton, known as primary producers, convert the sun's energy into food for all other life in the Gulf of Maine. Fish and shellfish abundance rely on primary production. 32 SeaFood Business September 2012 While collecting data in the Gulf of Maine, William Balch — a senior research scientist at Bigelow Labora- tory for Ocean Sciences in West Boothbay Harbor, Maine — noticed plumes of dissolved organic mat- ter showing up offshore. Washed out from rivers, such plumes typically stay relatively close to shore. Balch also noticed low-sa- years of the last century oc- curred between 2005 and 2010, according to that data and climatological data. "It's an extraordinary number, when you think about it," says Balch, "that half of the wettest years on record are since 2005." Tat influx of freshwater from rivers affected phyto- plankton production in two ways, says Balch. Te rivers carried larger-than-normal amounts of organic matter into the Gulf. Tink about how a teabag colors a cup of boiling wa- ter. In the Gulf, that mate- changes that occurred," says Balch, who analyzed ocean mea- surements "By all indications we are seeing an increase in lobster abundance in the Gulf of Maine that is strongly correlated with the decline in the abundance of large predatory groundfish." — Rick Wahle, research associate professor, University of Maine, School of Marine Sciences linity water far out at sea. Tose two clues hinted that something very unusual is underway in the Gulf of Maine, so Balch and his team rial absorbs blue light — the same wavelength of light used by phytoplankton. "It conceivably could have been shading or depriving the Visit us online at www.seafoodbusiness.com Photos courtesy of the Gulf of Maine Research Institute