Wednesday, January 25, 2006
Wintering Striped Bass
Many readers were surprised by the presence of over-winter striped bass in the Providence River. This is a relatively a recent phenomena observed since the mid-1990's, and may be related to a number of important changes in the Bay environment.
Striped bass in Narragansett Bay are known to spawn in the Hudson River and Chesapeake Bay esturies and to migrate seasonally along the East Coast. Bright fish from the Atlantic typically arrive on the Rhode Island Coast in April following the runs of alewives and blueback herring. In spring the stripers are abundant in the bay and its tributary rivers, feeding on menhaden, herring, squid, anchovies, and other forage species.
In the heat of summer, most stripers move to deeper colder water off Rhode Island's south coast and Block Island. In late summer and Fall they move back into the Bay, most staying until October or November before migrating south along the coast again. Most migrate, but not all.
Thousands of striped bass are known to winter in the cooling water canal of Brayton Point Power Station in Somerset, Massachusetts. Other winter populations in the Northeast tend to be associated with the warm outflows of power plants including the ones I found last week near the Manchester Street Station in downtown Providence. Others apparently stay in the Narrow River in Narragansett, where there are no warm water flows. A massive population now winters in the Thames River in Connecticut, upriver from the Millstone nuclear power plant.
After reading many reports about the Thames River fish, my wife Jillian and I took a ride to Norwich, CT on Sunday. In the harbor downtown, and all along the river, dozens of boats and hundreds of anglers braved ice and January temperatures to find them. It looked like a scene out of a cable TV bass fishing show, only colder. (No, I didn't fish because I don't have my '06 CT freshwater license yet!).
None of these striped bass wintering populations have been accurately counted or even estimated. Very little good scientific or natural history information is available. Striped bass is a great conservation success story, as populations coastwide have made a significant comeback since the lows of the mid 1980's thanks to better fisheries management, habitat protection, and improved water quality. Water temperature, and everything related to it, is probably a major factor in the increasing winter populations. Milder winters and warm-water flows have allowed stripers and the creatures they feed on to survive and even thrive in the Bay in winter.
It's not just stripers. The populations and assemblage of fish and other marine life is clearly shifting in Narragansett Bay from colder water species like flounder and cod to more temperate species like striped bass and sand shrimp. Is it global climate change? Natural cycles? We'll talk more about the Bay's overall fish populations in an upcoming post. JT