@article {2920,
	title = {Long-term cultural eutrophication in White and Walden Ponds (Concord, Massachusetts, USA), Thoreau{\textquoteright}s lakes of light},
	journal = {Lake and Reservoir Management},
	volume = {37},
	year = {2021},
	month = {12/2020},
	pages = {2-18},
	chapter = {2},
	abstract = {Two historically important ponds in the vicinity of Boston, MA, were subjected to a comparative paleolimnological investigation of the timing and causes of eutrophication trends in each. The remarkable clarity of White Pond during the early 19th century led Henry David Thoreau to compare it favorably to nearby Walden Pond, but during the 20th century water quality in both ponds declined. Sediment core studies show that cultural eutrophication began at Walden during the 1930s, but no long-term sediment records have been available for White Pond, which makes it more difficult to determine the history and causes of eutrophication there. Here we use microfossil and geochemical analyses of sediment cores to show that major changes in the diatom community of White Pond began around 1900, when fish stocking commenced and soil erosion due to land use in the watershed increased, and that the trend intensified around 1960 and 1990. We also describe efforts to mitigate eutrophication at White Pond, highlight the ecological importance of benthic vegetation in nutrient cycling, and suggest that threats to water quality in both of these ponds will likely increase due to anticipated climatic changes in the region.},
	keywords = {diatoms, eutrophication, paleolimnology, reclamation, Thoreau, Walden},
	issn = {1040-2381},
	doi = {10.1080/10402381.2020.1839606},
	url = {https://www.tandfonline.com/doi/full/10.1080/10402381.2020.1839606https://www.tandfonline.com/doi/pdf/10.1080/10402381.2020.1839606},
	author = {Stager, J. Curt and Harvey, Lydia and Chimileski, Scott}
}
@article {2674,
	title = {{\textquotedblleft}New{\textquotedblright} cyanobacterial blooms are not new: two centuries of lake production are related to ice cover and land use},
	journal = {Ecosphere},
	volume = {11},
	year = {2020},
	month = {Jan-06-2020},
	abstract = {Recent cyanobacterial blooms in otherwise unproductive lakes may be warning signs of impending eutrophication in lakes important for recreation and drinking water, but little is known of their historical precedence or mechanisms of regulation. Here, we examined long-term sedimentary records of both general and taxon-specific trophic proxies from seven lakes of varying productivity in the northeastern United States to investigate their relationship to historical in-lake, watershed, and climatic drivers of trophic status. Analysis of fossil pigments (carotenoids and chlorophylls) revealed variable patterns of past primary production across lakes over two centuries despite broadly similar changes in regional climate and land use. Sediment abundance of the cyanobacteriumGloeotrichia,a large, toxic, nitrogen-fixing taxon common in recent blooms in this region, revealed that this was not a new taxon in the phytoplankton communities but rather had been present for centuries. Histories ofGloeotrichiaabundance differed strikingly across lakes and were not consistently associated with most other sediment proxies of trophic status. Changes in ice cover most often coincided with changes in fossil pigments, and changes in watershed land use were often related to changes inGloeotrichiaabundance, although no single climatic or land-use factor was associated with proxy changes across all seven lakes. The degree to which changes in lake sediment records co-occurred with changes in the timing of ice-out or agricultural land use was negatively correlated with the ratio of watershed area to lake area. Thus, both climate and land management appeared to play key roles in regulation of primary production in these lakes, although the manner in which these factors influenced lakes was mediated by catchment morphometry. Improved understanding of the past interactions between climate change, land use, landscape setting, and water quality underscores the complexity of mechanisms regulating lake and cyanobacterial production and highlights the necessity of considering these interactions-rather than searching for a singular mechanism-when evaluating the causes of ongoing changes in low-nutrient lakes.},
	keywords = {agriculture, basin morphometry, Cyanobacteria, eutrophication, Gloeotrichia, ice-out, land use, Maine, New Hampshire, paleoecology, Sediment chemistry, watershed},
	issn = {2150-8925},
	doi = {10.1002/ecs2.v11.610.1002/ecs2.3170},
	url = {https://esajournals.onlinelibrary.wiley.com/doi/full/10.1002/ecs2.3170},
	author = {Ewing, Holly A. and Weathers, Kathleen C. and Cottingham, Kathryn L. and Leavitt, Peter R. and Greer, Meredith L. and Carey, Cayelan C. and Steele, Bethel G. and Fiorillo, Alyeska U. and Sowles, John P.}
}
