Varves WG in PNAS

A new study from the PAGES-endorsed Varves Working Group identifies urban expansion as the reason for low-oxygen rates in European lakes beginning in 1850.

Written by Jean-Philippe Jenny et al. and published yesterday in PNAS, "Urban point sources of nutrients were the leading cause for the historical spread of hypoxia across European lakes" uses a compilation of data from 1500 European watersheds to identify the relative role of different drivers in initiating hypolimnetic hypoxia, a critical indicator of lake health.

The authors also discovered a significant acceleration in the spread of lacustrine hypoxia in the 1900s - well before the general use of commercial fertilizers in the mid-20th century and the onset of supraregional climate warming in the 1970s.

Read the Canadian INRS (Institut national de la recherche scientifique) press release here.

Access the article here.