Data from: The legacy of large regime shifts in shallow lakes

Ecological shifts in shallow lakes from clear-water macrophyte-dominated
to turbid-water phytoplankton-dominated are generally thought of as rapid
short-term transitions. Diatom remains in sediment records from shallow
lakes in the Prairie Pothole Region of North America provide new evidence
that the long-term ecological stability of these lakes is defined by the
legacy of large regime shifts. Here we examine the modern and historical
stability of eleven shallow lakes. Currently, four of the lakes are in a
clear-water state, three are consistently turbid-water, and four have been
observed to change state from year to year (transitional). Lake sediment
records spanning the past 150-200 years suggest that: 1) the diatom
assemblage is characteristic of either clear or turbid lakes; 2) prior to
significant landscape alteration, all of the lakes existed in a regime of
a stable clear-water state; 3) lakes that are currently classified as
turbid or transitional have experienced one strong regime shift over the
past 150-200 years, and have since remained in a regime where turbid-water
predominates; and 4) top-down impacts to the lake food web from fish
introductions appear to be the dominant driver of strong regime shifts,
and not increased nutrient availability. Based on our findings we
demonstrate a method that could be used by lake managers to identify lakes
that have an ecological history close to the clear-turbid regime
threshold; such lakes might more easily be returned to a clear-water state
through biomanipulation. The unfortunate reality is that many of these
lakes are now part of a managed landscape and will likely require
continued intervention.