@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 {2612,
	title = {Climate variability and cultural eutrophication at Walden Pond (Massachusetts, USA) during the last 1800 years},
	journal = {PLOS ONE},
	volume = {131786944304936355638925103443261363251824210727417625108525645371825392233490545519069849653235772249},
	year = {2018},
	month = {Apr-04-2018},
	pages = {e0191755},
	abstract = {Recent shifts in the ecological condition of Walden Pond, MA, are of
potentially wide interest due to the lake{\textquoteright}s importance as a cultural,
historical, and recreational resource in addition to its scientific
value as an indicator of local and global environmental change. Algal
microfossils in six sediment cores document changes in hydroclimate and
trophic status of the lake during the last 1800 years and extend two
previous sediment core records of shorter length. Low percentages of
planktonic diatoms in the longest cores (WAL-3, WAL-15) indicate
shallowing and/or greater water clarity associated with a relatively
arid interval during the Medieval Climate Anomaly, ca. A.D. 1150-1300,
Cultural eutrophication of the lake since the A.D. 1920s caused diatoms
in the genera Asterionella and Synedra to increase in relative abundance
at the expense of Cyclotella, Discostella, and the chrysophyte alga
Mallomonas allorgel. Percentages of Asterionella and Synedra have
remained fairly stable since A.D. 2000 when a previous sediment core
study was conducted, but scaled chrysophytes have become more numerous.
These findings suggest that, although mitigation efforts have curtailed
anthropogenic nutrient inputs to Walden Pond, the lake has not returned
to the pre-impact condition described by Henry David Thoreau and may
become increasingly vulnerable to further changes in water quality in a
warmer and possibly wetter future.},
	keywords = {BOREAL LAKES, canada, CRAWFORD LAKE, DEPTH MODELS, ENVIRONMENTAL-CHANGE, ice-age, new-england, NORTH-AMERICA, NORTHEASTERN UNITED-STATES, organic-matter},
	doi = {10.1371/journal.pone.0191755},
	url = {https://www.sciencedaily.com/releases/2018/04/180404143418.htm},
	author = {Stager, J. Curt and Wiltse, Brendan and Hubeny, J. Bradford and Yankowsky, Eric and Nardelli, David and Primack, Richard},
	editor = {Doi, Hideyuki}
}
