Jake Vander Zanden: Lake Dead Zones

Reporting from New Zealand:

UW-Madison’s Limnology Center: Earlier this year, Jake Vander Zanden rented his house out in Madison, packed his things, and headed with his family for a sabbatical in New Zealand. Under the auspices of a Fulbright scholarship, Jake is at the University of Waikato, studying ‘dead zones’ in lakes, where pollution reduces oxygen making it impossible for parts of lakes to support life.

Tell us about your research here in New Zealand
I’m looking at the phenomenon of lake ‘dead zones’. Lakes that in the past had a lot of oxygen in the bottom waters can lose that oxygen due to nutrient pollution – often from human activity – then they become an environment that can’t support life. You lose a lot of the value that would come from a lake, such as fisheries, when you have dead zones.

It seems like once you create dead zones they are difficult to turn back. Even if you remove nutrients and improve conditions, the healthy ecosystem never returns. That’s really worrisome because it is so difficult to fix the problem. Another consideration is that when you create a dead zone, the plant nutrient phosphorus is released from the lake sediments, which further contributes to the pollution problem.