Tohu Paerunga Mātai Koiora o te MoanaPostgraduate Marine Biology

My research investigates how benthic marine ecosystems function, how they respond to environmental change, and how they can be more effectively monitored, protected and restored. It spans biological scales, from the microorganisms living within marine animals to entire communities and seascapes, and environmental gradients extending from shallow coastal habitats into mesophotic waters. I combine long-term field ecology with controlled experiments, microbial and molecular approaches, scientific diving, underwater robotics and advanced imaging.

 

Sponges are central to much of this research. They are abundant and ecologically important habitat-forming organisms that influence biodiversity, nutrient and carbon cycling, benthic–pelagic linkages and coastal productivity. Despite these roles, sponges remain poorly represented in many marine research, monitoring and conservation programmes. My work examines the processes controlling sponge diversity and abundance, the functions sponges perform, and the consequences of their decline, proliferation or replacement of other habitat-forming organisms.

 

A major component of my research uses laboratory and field experiments to determine how sponges, temperate corals and other benthic organisms respond to environmental stress. This includes ocean warming and marine heatwaves, ocean acidification, deoxygenation, sedimentation, nutrient enrichment, plastic pollution and the effects of fishing. By measuring physiological performance, survival, reproduction, recruitment and recovery, this work seeks to identify the mechanisms and thresholds that determine whether ecologically important species persist under future environmental conditions.

 

Sponges also host diverse microbial communities that can strongly influence their nutrition, health and environmental tolerance. My research investigates how these microbial partnerships respond to stress and whether changes in the microbiome contribute to acclimation, carry-over effects

Coral reef biology and marine symbiosis, especially cnidarian-dinoflagellate symbiosis

The central goal of my research is to use population genomics, whole-genome sequencing and bioinformatics to understand how populations respond to environmental change and to improve the conservation and management of exploited and threatened species in Aotearoa New Zealand.

Impacts of climate change of fish and fisheries

My research interests are largely focused on examining the drivers and processes that control and maintain biodiversity in the marine environment. Specifically, I’m interested in exploring the relationship between the biodiversity of seafloor fauna and habitat heterogeneity, productivity and disturbance. To understand these relationships, I have been involved in research in a range of marine habitats from the intertidal to the deep sea. Some of his research has concerned applied aspects of marine science: such as determining the effects of fishing, aquaculture and seabed mining on seafloor fauna, and the production of habitat suitability models, environmental classifications, and ecological risk assessments for conservation and management purposes. I’m also interested in the philosophical, ecological, and practical issues that relate to identifying and describing 'biological communities'.

I’m currently working on projects looking at the impact of disturbance by seabed mining and turbidity currents on seafloor communities in the deep sea, and those that involve the development of habitat suitability models for the management of impacts on vulnerable marine ecosystems.

- Ecophysiology, toxic freshwater cyanobacteria, Antarctic algae, marine ecology, electron microscopy, light microscopy
- Climate change biology – Ecophysiological effects of pH, temperature, UVB, and salinity on organisms in Antarctic coastal marine ecosystems
- The growth and toxin production of cyanobacteria in river systems
- Light and electron microscopy remain a strong interest although I don't do much of this now.

My research examines the population dynamics of marine and freshwater organisms with complex life histories, including reef fishes, mesopelagic fishes, corals, and aquatic fishes/invertebrates. I focus on understanding how dispersal, connectivity, recruitment dynamics, and population regulation shape population persistence and variability across spatial and temporal scales.

 

I use a diverse toolkit that combines field‑ and laboratory‑based experiments, underwater surveys, long‑term observational studies, otolith‑based life‑history and demographic reconstructions, and ecological theory. A central theme of my work is the role of early life‑history processes and eco‑evolutionary feedbacks in driving life‑history variation, population structure, and ecosystem dynamics.

 

My research addresses questions relevant to the management of harvested marine species and seeks to predict how populations respond to natural perturbations, climate change, and human‑induced environmental change. Current research programmes are based in New Zealand and French Polynesia, with particular emphasis on temperate and tropical reef systems and the role of mesopelagic fishes in trophic connectivity and oceanic carbon transport.

 

Seaweed, algae, evolution, phylogenetics, Taxonomy, applied phycology