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The core group of academic staff and postgraduate students are located at the University of Otago but we work in collaboration with other New Zealand universities as well as governmental agencies such as NIWA.

Coastal People: Southern Skies is a research collaboration that connects communities with world-leading, cross-discipline research to support transformative change to rebuild coastal ecosystems. Our researchers are significant contributors to this collaboration.

Our Ocean Acidification research

Dr Linn Hoffman, Director

Dr Linn Hoffman's work focuses on the effect of different environmental stressors for marine phytoplankton physiology and ecology. I am thereby mainly interested in the effect of climate change related stressors such as ocean acidification and ocean warming and the effect of trace metals e.g. from volcanic eruptions on marine phytoplankton and the implications for higher trophic levels of the food chain. I also work on biomechanical properties of diatom frustules and how they are affected by environmental conditions.

  • What is the effect of trace metal release from volcanic eruptions for marine phytoplankton species distribution and productivity?
  • How does ocean acidification affect trace metal bioavailability and what are the implications thereof for marine phytoplankton?
  • How is phytoplankton species distribution in the Southern Ocean affected by climate change?
  • Does bioaccumulation of iron by seabirds enhance productivity around sub-Antarctic Islands?

Dr  Kim Currie

Dr Kim Currie is  for the New Zealand Ocean Acidification Observing Network (NZOA-ON), a coastal monitoring programme, and is also involved in the broader ocean acidification research area, looking at the responses of various New Zealand species and ecosystems in collaboration with botanists, ecologists, geologists, and zoologists and social scientists.

Her research focuses on the spatial and temporal variability of the oceanic uptake of CO2, and the consequences of the changing marine carbon cycle. We have been monitoring the changes in the carbon chemistry of the surface waters off Otago, New Zealand, since 1998 using a time series approach. Research associated with The Munida Time Series has identified factors affecting the marine carbon chemistry, including changes in pH, on seasonal, annual and long-term time frames.

Associate Professor Chris Hepburn

Associate Professor Chris Hepburn has interests in kelp forest ecosystems and sub-tidal reefs and has current projects focusing on:

  • Customary and ecosystem-based fisheries management
  • Fisheries restoration
  • Integrated aquaculture
  • Impacts of elevated CO2 on coastal ecosystems
  • Ecology and physiology of macroalgae
  • Invasion by exotic marine organisms
  • Macroalgal / invertebrate interactions
  • Taiāpure Fish-tagging Program

Cliff Law

Cliff Law is a Principal Scientist in the Ocean-Atmosphere Group at NIWA, with broad research interests in the interactions between ocean biota and marine and atmospheric chemistry. One research area focuses on the influence of climate change and ocean acidification on microbial production and biodiversity in the surface ocean.

Current research projects investigate the impact of ocean acidification on carbonate-forming plankton (MFish funded), and on bacterial degradation of organic matter (Marsden funded). He has also recently developed a NZ Climate Change Atlas for the Oceans with Phil Boyd in the NIWA Centre of Excellence in the Department of Chemistry, University of Otago.

Dr Christina McGraw

Dr Christina McGraw has broad interests in analytical and marine chemistry, my research revolves around the design of field-deployable instrumentation for marine ecosystems.

Current projects include:

  • The effect of anthropogenic CO2 on our marine ecosystems
  • Deployable environmental sensors
  • Materials and methods for ion-selective electrodes

Malcolm Reid

Malcolm Reid has been developing apparatus and conducting measurements of seawater pH for many years using spectrophotometric techniques. In conjunction with Dr Kim Currie, measurements have been made on most of the cruises from the Munida time series where near continuous pH has been measured using the method described in Tapp et al. (2000) and Ohline et al. (2007). He has also used a more advanced system on many open ocean cruises on larger vessels, mainly for surface samples, but he has trialed measurements on discrete samples from depth profiles.

More about our research interests can be found in the Our people page.

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Research collaborators

NZOAR has a number of collaborators from research entities throughout New Zealand as well as affiliates abroad.

Helen Bostock, Geochemist - NIWA

Helen Bostock is a geochemist working on the carbonate mineralogy of New Zealand’s benthic organisms and looking at their spatial and depth distribution with respect to the carbonate ion concentrations and saturation. She has been developing some algorithms, in collaboration with oceanographic colleagues, to estimate the carbonate saturation state in the water column from hydrographic parameters (temperature, salinity, oxygen).

Philip Boyd, Affiliate - Institute for Marine and Antarctic Studies, University of Tasmania

Philip Boyd's investigations focus on the effects of climate change – multiple stressors, including pH – on ocean biota, in general, and on marine phytoplankton, in particular.

Catriona Hurd, Affiliate - Institute for Marine and Antarctic Studies, University of Tasmania

Catriona Hurd investigates seaweeds. Seaweeds form the base of coastal marine ecosystems worldwide, supplying energy to higher trophic levels. Catriona’s research focuses on how physical (water motion), chemical (carbon, nitrogen supply), and biological (invertebrates) interactions affect algal productivity, and includes the impacts of human-induced environmental change (e.g., ocean acidification (OA), invasive algae, eutrophication) on ecosystem health.  Catriona’s research group is examining interactions between OA and water motion (seaweeds); OA, temperature, and nutrients (phytoplankton); OA and UV (seaweeds); and nitrogen source and UV (seaweeds).  She is particularly interested physiological plasticity and the rate at which algae can acclimate, and/or adapt to ultimately evolve in new environmental conditions, and on the ability of primary producers to modify their own pH environment (e.g., Hurd et al. 2011).

Norman Ragg, Research Scientist, Cawthron Institute

Norman Ragg leads the physiology team at Cawthron, drawing on a background of work in the aquaculture industry combined with training as a classical biologist focusing on physiology. This is brought to bear in a range of projects where the physiology of aquaculture species is a key issue.

Mary Sewell, Associate Professor in Ecology, Evolution and Behaviour – University of Auckland

Mary Sewell investigates sea urchins which are important macroinvertebrates on subtidal rocky reefs in temperate, tropical and polar environments. Previous research on the response of sea urchin larvae to ocean acidification has generally shown smaller larval sizes and evidence for metabolic depression. The research Mary’s group is conducting on the endemic Evechinus chloroticus is taking a systems biology approach to understand the mechanistic basis of metabolic depression at the whole organism level and through study of the genome, proteome and metabolome.

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Postgraduate research

Work on ocean acidification by postgraduate students is growing. Students may have the opportunity to becoming published scientific authors during their study. This is a selection of recent research projects.

Zhaleh Adhami, PhD, Chemistry

Zhaleh is studying factors influencing the dissolution kinetics of calcium carbonate under conditions of ocean acidification. Her proposed study will apply the pH-stat technique to investigate the effects of the nature of CaCO3 used and of the seawater composition on the kinetics of calcium carbonate dissolution at steady-state disequilibrium. The rate and kinetics of dissolution can be described based on the volume of HCl consumption and the empirical equation R = k(1-Ω)n.

Patila Amosa, PhD, Chemistry

Patila is studying the kinetics and mechanisms of biogenic calcium carbonate dissolution. The major goal of her thesis project is to determine the individual and combined impacts of carbonate mineralogy, saturation state, pH, temperature, and surface area on the rate of dissolution of biogenic calcite and aragonite. It is hoped that these measurements will contribute to existing information on the controls of biogenic carbonate dissolution kinetics. As the saturation state of aragonite in surface tropical seawater is expected to decrease by the middle of the next century by 30% (Kleypas et al., 1999) resulting in increased dissolution and subsequently diminishing the benefits that reefs provide (Kleypas, 2011), Patila’s experiments will explore the dissolution of tropical coral samples, specifically from Samoa. She will also measure the dissolution rate of selected temperate bryozoan species for a comparative study of the two ocean regimes.

Johanna Brinkman, MSc, Marine Science

Johanna’s research involves using natural CO2 seeps as a proxy for studying ocean acidification. Natural CO2 vents at White Island, Bay of Plenty, create low pH and high temperature environments that mimic conditions predicted for OA. By studying the carbonate mineralogy of marine calcifiers, such as sea urchins, tube worms and crustose coralline algae, we are able to make in situ observations of how OA will affect marine organisms in the future.

Yuanyuan Feng, PhD, Botany

Effects of projected future pCO2 and temperature increases, in addition to changing of irradiance and nutrient availability, on two marine phytoplankton functional groups, diatoms and coccolithophores, in New Zealand coastal and Antarctic waters. By conducting a series of laboratory incubation experiments, Yuanyuan is trying to understand the physiological effects of Ocean Acidification (OA) on different phytoplankton groups and the interactive effects of OA with other environmental factors on theses groups. In addition, Yuanyuan would like to study how the natural phytoplankton community in NZ coastal waters will respond to global warming, and the consequent changes in sea water biogeochemistry.

Feng, Y., Hare, C.E., Rose, J.M., Handy, S.M., DiTullio, G.R., Lee, P.A., Smith, W.O., Jr., Peloquin, J., Tozzi, S., Sun, J., Zhang, Y., Dunbar, R.B., Long, M.C., Sohst, B., Lohanm, M., Hutchins, D.A. (2010). Interactive effects of iron, irradiance and CO2 on Ross Sea phytoplankton. Deep Sea Research I. 57:368-383.

Feng, Y., Hare, C.E., Leblanc, K., Rose, J.M., Zhang, Y., DiTullio, G.R., Lee, P.A., Wilhelm, S.W., Rowe, J.M., Sun, J., Nemcek, N., Gueguen, C., Passow, U., Benner, I., Brown, C., Hutchins, D.A. (2009). Effects of increased pCO2 and temperature on the North Atlantic spring bloom: I. The phytoplankton Community and Biogeochemical Response. Marine Ecology Progress Series. 388: 13-25.

Pamela Fernández, PhD, Botany

Most ocean acidification (OA) studies have evaluated the effects of high CO2 concentrations as an independent stressor on calcifying organisms and physiological processes such as calcification, acquisition of Ci (inorganic carbon), photosynthesis and photorespiration. Little attention has been paid to the combined effects of OA with other possible anthropogenic changes, which are also projected by the next century, such as a possible decrease in nitrification rates, or increase of inorganic nutrients (N and P). Pamela’s research focuses on the effects of OA and nutrient availability on physiological parameters related to C metabolism – photosynthesis, carbonic anhydrase activity – and N metabolism – uptake rate, nitrate reductase activity – in populations of the giant kelp, Macrocystis pyrifera, while also evaluating the effects of these physiological processes on seawater chemistry.

Emily Frost, MSc, Zoology

Antarctica is professed as being one of the most susceptible regions in the world to ocean acidification. Antarctica’s augmented CO2 solubility and highly sensitive acid-base dissolution coefficients, ensues in rapid pH declines and aragonite undersaturation within its surface waters. Additionally, early life-history stages of benthic calcifiers (echinoderms) are particularly vulnerable to hypercapnia (elevated CO2 concentrations). Emily’s research focuses on the impacts of elevated oceanic CO2 on the activity, genetic expression, and location (through in situ hybridizations) of the Na+/K+-ATPase pump (maintains cellular Na+ and K+ gradients). This will be explored within the embryo and planktotrophic larval stages of Antarctic – Sterechinus neumayerii – and temperate New Zealand – Evechinus chloroticus – sea urchins.

Pablo Leal, PhD, Botany

Among the consequences of increase in atmospheric CO2 are the acidification and warming of the world’s oceans. Ocean acidification changes seawater carbonate chemistry, pH and the availability of free metal ions (speciation). These changes can potentially affect different processes – e.g., spore germination, gamete release and fertilization – of the development of early life stages – i.e., spores, gametes, embryo and juvenile sporophyte – of seaweeds. Pablo’s research aims to provide new information about the effects of the interaction of different abiotic factors – i.e., ocean acidification, temperature and copper availability (speciation) – on different life cycle stages of non-calcareous algal species (Macrocystis pyrifera, Undaria pinnatifida and Xiphophora gladiata).

Colin Macleod, PhD, Zoology

Colin studies the effects of ocean acidification (OA) on host-parasite associations. Specifically, he investigates the effects of the physiological stressors caused by OA on a group of trematode parasites and their gastropod hosts. These stressors could alter host-parasite interactions, such as parasite transmission success, pathogenicity, and host susceptibility to infection, and reduce host or parasite survival. Changes to these parameters could lead to a disruption of interspecific relationships between hosts and coexisting species (e.g., predators or competitors) and result in reduced community biodiversity and ecosystem stability

Collette Rivera, MSc, Marine Science

Collette is looking at the effect of increasing ocean acidity on the development of urchin larvae. Of particular interest is the development of the rudiment – the stage of metamorphosis between the larval and the settling urchin. Collette would like to determine whether there is reduced growth or development of the rudiment in lowered pH. She is focusing on the New Zealand urchin species, Pseudechinus huttoni, and the Antarctic species, Sterechinus neumayeri.

Kate Sparks, PhD, Marine Science

Kate’s research focuses on the responses of marine invertebrates to near future ocean conditions under global climate change. She is mostly interested in how the very early life stages (i.e., from fertilisation to larvae) are affected by lowered pH and increased temperature. Kate looks at echinoderms as model organisms.