Sunday, May 3, 2015

Research @ Otago - Josie Crawshaw

Josie Crawshaw is studying the role of coastal lagoons and estuaries in removing nitrate from the water column before it reaches the ocean.
Josie collecting a sediment core from an enclosure at Lake Ellesmere
Our coastal waters are experiencing an increase in nutrient loading, due to increases in agricultural farming. Luckily, coastal ecosystems such as coastal lagoons and estuaries can perform an extremely important ecosystem function, and remove nitrate from the water column, before it reaches our oceans. This process is called denitrification, which is the conversion of nitrate from the water column, into nitrogen gas, and it is carried out in the sediment by denitrifying bacteria. Knowing what factors might influence this process, and how efficiently these systems can carry out this process is an important component that needs to be considered in catchment models of allowable nutrient loading.
The flexible enclosure in place
To study this, Josie has designed and built flexible in situ enclosures, which enclose a section of the water column and sediment. She uses stable isotope tracers to follow the conversion of nitrate to nitrogen gas and nitrous oxide.
Taking water samples from enclosures on windy days requires good balance!
Josie is also a keen diver, and an ambassador for Atlantis Dive. She tries to get out as often as she can, especially on research dives!

You can follow Josie's research and diving journey on the following pages.

1 comment:

  1. I think this is a really helpful research by using isotope. what's more. I also believe that the stable isotope can help a lot.