Seasonal changes in near-bottom dissolved oxygen concentrations collected during 2005 by the GLERL-led International Field Years on Lake Erie indicate severe depletion (hypoxia) of oxygen in Lake Erie’s Central Basin. Further study and documentation of the formation of such "dead zones" will allow scientists to develop predictive models and forecast future location and extent of such areas. Note: do not cite or publish this figure or data depicted in it without the express permission of IFYLE scientists Stuart Ludsin or Tom Johengen.