Cover Image

Equatorial mountain lakes show extended periods of thermal stratification with recent climate change

Neal Michelutti, Andrew L. Labaj, Christopher Grooms, John P. Smol
  • Andrew L. Labaj
    Queen’s University, Canada
  • Christopher Grooms
    Queen’s University, Canada
  • John P. Smol
    Queen’s University, Canada


Climate change in the Andes has already affected phenology, glaciology, and other ecosystem attributes, and now threatens to alter long-standing fundamental limnological properties. In the equatorial Andes, most lakes have traditionally been described as having waters that circulate continuously (polymictic), with only rare episodes of stratification. This characterization, albeit based on relatively few studies, is widely accepted, despite accelerated regional warming over the past 30 years.Here, we show that protracted periods of thermal stratification are presently the norm, not the exception, in equatorial mountain lakes. Annual circulation and stratification patterns recorded in four lakes from Ecuador’s southern Sierra show extended periods of stratification, which are stable and do not break down with nocturnal cooling. These data contrast with earlier research from this region, which reported full water column mixing and only infrequent stratification, but are not surprising in light of recent trends toward rising temperatures and declining wind velocities. Paleolimnological studies show that changes to the thermal regimes of these lakes likely began several decades ago and have resulted in ecosystem-scale changes including regime shifts in phytoplankton and declines in aquatic production.


Tropical Andes; Ecuador; lakes; climatic change; thermal stratification.

Full Text:

Suppl. - temperature data
Submitted: 2016-01-29 19:18:48
Published: 2016-03-29 00:00:00
Search for citations in Google Scholar
Related articles: Google Scholar
Abstract views:

Suppl. - temperature data

Article Metrics

Metrics Loading ...

Metrics powered by PLOS ALM

Copyright (c) 2016 Neal Michelutti, Andrew L. Labaj, Christopher Grooms, John P. Smol

Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.
© PAGEPress 2008-2018     -     PAGEPress is a registered trademark property of PAGEPress srl, Italy.     -     VAT: IT02125780185     •     Privacy