The core of our project is set in four headwater streams. These streams contained only one species of fish, the killifish Rivulus hartii. We experimentally introduced guppies into a short section of each stream (80-150 meters) to examine the ecological and evolutionary changes that take place when guppies move into these habitats. The downstream side of the introduction site was defined by a barrier waterfall. The upstream dispersal of guppies was limited by another barrier waterfall. We also study a “control” reach above the guppy introduction sites.
David Reznick provides an onsite introduction to these experiments.
David provides some more detail about how the guppies have taken to their new environment.
In one of the streams, we did not find a barrier waterfall to limit our introduction reach. So we built one...
An important component of our research involves tracking the response of killifish to guppies. Brad Lamphere introduces this aspect of our work.
In addition to tracking guppies and killifish, we also have looked at ecosystem level responses. Steve Thomas describes our work on this front.
Primary productivity represents a key ingredient in our ecosystems perspective. To better understand how light and productivity influence these streams we have thinned the canopy near 2 of the streams. Steve explains.