Research @ Otago - Nadjejda Espinel

Nadjejda is studying the effects of climate change on marine ecosystems, and marine invertebrates in particular.   

Nadjejda raises the microscopic larvae in the laboratory

Nadjejda's research focuses on the effects of ocean acidification and warming on the larval settlement of some New Zealand key species including paua, kina, barnacles (Austrominius modestus) and polychaetes (Galeolaria hystrix), trying to understand how these species will fare in future acidified and warmed-up oceans.

The approximate size of the Nauplius larvae is 0.5mm

Most of the sessile  (organisms that live attached to the substrate) and benthic marine invertebrates spawn planktonic larvae into the water column. These larvae swim freely until they find a place appropriate to spend their adult lives and then they settle and metamorphose - this is what we call the settlement process. Any factors influencing the settlement process might influence the future distribution of species and ultimately the diversity of the marine ecosystems.  The settlement process could be influenced by direct changes in the larval physiology, or by indirect changes in the settlement substrates.

Nadjejda collecting adult barnacles from the rocks at Portobello Marine Laboratory

In order to study this, Nadjejda collects invertebrates (adults), spawns them and rears the larvae in the lab, in order to get them to settle. The core of her research comprises experiments in the lab trying to settle larvae in different pH treatments on different types of substrates, in order to see whether a significant effect can be expected at the future predicted levels of acidification and warming.