John Zeldis

Job title and place of work

Principal Scientist Marine Ecology, NIWA, Christchurch.

What is your role in the CARIM project? What work package are you contributing to?

Leader Biogeochemical modelling - Work Package RA2

I lead the Research Aim which is building a variety of models that describe acidification in coastal waters. We intend that as well as understanding the present situation, our modelling will enable us to make predictions about what might happen in the future.


What do you do on an average work day?

I have been building a model which describes the ‘when’, ‘where’ and ‘why’ of coastal acidification in the Hauraki Gulf and Firth of Thames. The model uses oceanographic data we have collected during NIWA ship surveys in the Hauraki Gulf, combined with water quality data from rivers from regional councils and NIWA.    

Why is studying coastal acidification important?

In many parts of the world, the pH of coastal waters is decreasing (worsening) at a much faster rate than it is in the open ocean. Acidification can be stressful for marine animals and plants that rely on carbonate structures for shell-making, and even for those that don’t, such as larval fish. This is serious because so many important elements of natural marine ecosystems exist in coasts, including many of the resources we use.       

What study did you do at high school? And after high school?

In high school I studied English, Spanish and all branches of science. At University I concentrated on sciences, but I still dabbled in stuff like Russian literature and anthropology.

What outcomes from CARIM do you think there will be?

I think we will understand a lot more about what causes coastal acidification, and what we might be able to do about it. We also will learn about what effects it is having now, and could have in the future, on some important elements of the marine ecosystem. 

What excites you about working on this project?

I get to use what I’ve learned over many years of doing marine research, to hopefully ‘make a difference’ in the health of our marine environment.