• The state of ice coverage on Maine lakes has become an increasingly prominent concern. It appears, based on ice-out data, that over the past 100 years there has been a substantial shift towards earlier ice-outs. This means it is likely that ice is covering lakes for less of the year. Extended periods of ice cover is one of the reasons why Maine has such high quality lakes compared to many other parts of the United States. Blooms of cyanobacteria and algae, and certain invasive species are all tempered or prevented from establishing due to the long, cold winters.
  To discuss ice further we need to understand the terminology and complications of monitoring it. Both ice-in and ice-out are localized events defined by the observers. At Lake Stewards of Maine (LSM), we have provided some guidelines that individuals or lake associations can use. However, if there are historical observations, the observers should maintain that same criteria for determining these events. The consistency is vitally important to pick up on changes over time.
  The monitoring by our citizen scientist network remains a critical component for understanding our lakes. In the mid-2000s, using data, including that collected by LSM volunteers, USGS Hydrologist Glenn Hodgkins was able to determine that the duration of ice cover for a number of New England lakes has been diminishing over the past century. This same conclusion has been arrived at by Lloyd Irland, PhD. This past summer LSM hosted Dr. Irland as a part of our summer webinar series. A recording of the session, Lake Ice Regimes: Some Baffling Trends and Challenges for Citizen Science, can be found HERE.
  
  
  
  
  
  Charts by Lloyd C. Irland, from research now being prepared for publication.
  
  Both ice-in and ice-out are really proxies for climate change and variations between seasons. The charts of average ice-out dates (above) show the movement towards an earlier ice-out, indicated by the negative slope of these two trend lines. One of the important take-aways is that there is significant variation between the years and even decades. It is only with long-term data sets that trends can be identified. Ice-out has a more robust historical record in many communities -- this may be due to the celebratory nature of warming weather and the autumn harvests and preparing for the colder months ahead. Although ice-in data is patchy and does not have as long a history as ice-out data, what is available indicates ice-in dates are becoming later. This double-sided attack -- later icing over in the fall and earlier retreat of ice in the spring -- is another troubling indicator of climate change and a warming Maine, more prone to algae blooms and invasive organisms.
  If you’re interested in getting involved in ice data collection please check out the information available on our website and contact us HERE.
  
  

Learn more about Sebago Lake HERE or check out conservation areas near it HERE

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A key reason for the Cooper surveys was to evaluate lakes for fish-stocking. They collected data on: lake depth, water temperature, dissolved oxygen, pH, phosphorus, benthic invertebrates, and plankton & fish communities. Cooper did not measure water transparency. Therefore (and unfortunately, given the ever-expanding base of Secchi data collected by LSM volunteers and others) it is not possible to explore how transparency in these lakes has changed over the 8 decades since these historical surveys were carried out.

The results of the surveys were published in a series of seven Fish Survey Reports. An interactive map showing where the lake surveys happened is HERE.

Cooper et al. used gill and seine nets to collect fish. Supplemented by information from fish & game wardens, they thus documented the structure of the fish community in each surveyed lake (species composition, diets, age/growth). By comparing these data with more contemporary data from IF&W, it is possible to examine changes in lake fish communities over the past ~ 60 years. Especially interesting is the ‘spread’ of such species as largemouth and smallmouth bass as a result of both intentional and illegal stocking (and ‘natural’ range expansion).

Explore these changes in Maine’s lake fish communities HERE.

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Also included in this undertaking are a number of regional entities, including Lakes Environmental Association, Cobbossee Watershed District, Mid-Coast Conservancy, 30-Mile River Watershed, 7 Lakes Alliance, Belgrade Lakes Association, Acton Wakefield Watershed Alliance, Allagash Wilderness Waterway, Portland Water District, Auburn Water District, Acadia National Park, and Rangeley Lakes Heritage Trust. Included are the sovereign nations of the Passamaquoddy Tribe at Indian Township, and the Penobscot Indian Houlton Band of Maliseets.

Data have also been acquired from private consultants, such as FBE and Lake & Watershed RMA, as well as others collecting lake data as part of regulatory requirements. Additional data are acquired through the DIF&W and through cooperative projects with the University of Maine System, Bates, Colby and Unity Colleges, and County Soil and Water Conservation Districts. Field data are also collected by the Maine DEP Lakes Assessment Section under probability-based studies conducted within EPA Region I, and as part of the National Lakes Assessment Study being conducted by EPA Headquarters.

We apologize if your lake data-gathering organization has been accidentally omitted. Please let us know if that is the case. Additional types of data are also submitted to the Lakes of Maine website, including Annual Loon Count data gathered by volunteers through Maine Audubon Society, and a variety of lake and watershed information provided by The Nature Conservancy.

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