Current Research and Collaborations

Much of my research focusses on human-mediated effects on marine systems and therefore contributes to management. A lot of the time my group uses molecular tools to answer ecological, environmental or evolutionary questions in the context of some form of disturbance. I am therefore keen to recruit postgraduate students who have similar interests and who have skills in molecular biology and/or the handling of big data sets. My present research interests can be loosely categorised as below, but there is considerable overlap amongst the topics.

Deep-sea Vulnerable Marine Ecosystems

Vulnerable marine ecosystems (VMEs) are defined as being physically fragile, structurally complex, slow to recover from disturbance or may never recover. VMEs are vulnerable to damage by human activities such as fishing, mining, dumping. My research interest here is mainly in how VME populations are connected in a genetic sense. My group uses a range of molecular markers (sequencing, microsatellites, SNPs) to quantify genetic connectivity in VME taxa such as corals and sponges, and in VME-associated taxa such as squat lobsters, to better understand spatial genetic structure. We also use environmental data to help explain the genetic structure that we observe (seascape genetics). This information is then used to provide management advice to the New Zealand government about the placement of new offshore marine protected areas. This work is carried out in collaboration with colleagues at NIWA, as well as with international collaborators in Australia, France and the USA.

Marine Reserves

I helped to establish the Taputeranga Marine Reserve at Island Bay on Wellington’s south coast. I am a big advocate for marine reserves (full no-take areas) and much of my work focusses on quantifying how the absence of human disturbance (fishing) has changed coastal communities. Typically my group works on invertebrates and vertebrates, and typically we try to work at a range of marine reserves. I am also very interested in trying to quantify connectivity amongst marine reserves, modelling past-present-future situations (scenario or “what if” type modelling), determining how best to monitor marine reserves, and quantifying spillover and larval export. A present focus is mapping of marine reserves to better understand which habitats and species are present, and to determine if the area that is protected is representative of the region. A lot of this research is carried out in collaboration with colleagues at DOC and NIWA.

Coastal connectivity and (invertebrate) fisheries

Although I am not a fisheries biologist I am interested in the genetic connectivity of coastal species. Previous work has focussed on surf clams, flat fish and scallops. Projects related to these species, and others such as paua (abalone), are of interest to me. This sort of work often benefits substantially from inclusion of a modelling component, e.g., physical oceanographic modelling using ROMS etc. We also use environmental data to help explain the genetic structure that we observe (seascape genetics). A lot of this research is carried out in collaboration with colleagues at NIWA, the Ministry for Primary Industries, the Paua Industry Council or AgResearch (for SNPs development).

Aquaculture

Over the years my group has developed a range of different marker types and applied to these to species such as greenshell mussels, Pacific oysters and flat oysters. Most of this work relates to the identification of population genetic structure within these species, but is also relevant to family breeding programmes, the collection of wild spat, and genetic stock identification. A lot of this research is carried out in collaboration with colleagues at The Cawthron Institute, SpatNZ and BreedCo.

Bioinvasions and biosecurity

The main focus here is the identification, usually via molecular methods, of an invader, but may also include identification of adverse effects such as competitive displacement, hybridisation and range expansion. Sometimes the invader has become an important component of the local ecosystem and/or an important aquaculture or fishery species. We also use environmental data to better understand the range expansion of the invader (seascape genetics). An additional component of this work is how to eradicate the invader or how to prevent further spread. Examples include blue mussels, the brown mussel in New Zealand and in India, and also the invasive kelp, Undaria pinnatifida. A lot of this research is carried out in collaboration with colleagues at The Cawthron Institute, and in Australia, Chile, Croatia, India and Poland. In collaboration with colleagues at the University of Waikato (NZ) and Murdoch University (Aus) we are also investigating how the built environment (wharves, pilings, sea walls, etc) may influence marine community development, structure and function.

Southern hemisphere distributions, taxonomy and systematics of blue mussels (Mytilus spp.)

In conjunction with colleagues in Poland, Chile and Australia, I am working on Southern hemisphere populations of blue mussels (Mytilus spp.) to better understand their evolutionary origin, rates of hybridisation and introgression, and the distributions of native species (biogeography). For this work, we have been using a range of molecular markers, including a new panel of SNPs that accurately and consistently differentiate amongst blue mussels from Chile, Argentina, New Zealand and Australia, and differentiate these Southern hemisphere mussels from their Northern hemisphere congenerics. This work has application to testing for provenance and traceability of mussels, given that in many parts of the world mussels are an important aquaculture or fishery resource.

Marine ecology

I have wide ranging marine ecology interests (see my publications) but much of my work is focussed on rocky temperate reefs and mussels in particular. I use lab-based and field-based ecophysiological and ecological experimentation to better understand why mussels are so abundant in Wellington Harbour but almost completely absent from the coastline of the rest of the Wellington and Wairarapa region. The focus of this work is the interaction between food supply (diet quantity and quality) and environmental tolerance.

Hybridisation

My PhD research was focussed on the ecological genetics of hybridisation between two smooth-shelled blue mussels, Mytilus edulis and M. galloprovincialis, in SW England. I am very interested in hybridisation in the sea - where, why and how it occurs (or doesn’t occur), and the evolutionary interactions and outcomes between hybridising taxa. Whilst lots of research has focussed on hybridisation on land, far less work has looked at hybridisation in the sea. Hybridisation can occur as both a completely natural event (e.g., interbreeding between two distinct evolutionary lineages of greenshell mussels in New Zealand) and as a consequence of human-mediated introductions (e.g., interbreeding of native and introduced blue mussels in New Zealand). Hybridisation is often said to be “a window on the evolutionary process” – this is why it is so interesting both to evolutionary biologists and to conservation biologists and managers who are concerned about the negative effects of hybridisation resulting from introduced species.

Work in China

I was a Chutian Scholar and Visiting Professor in the College of Fisheries at Huazhong Agricultural University (HZAU) in Wuhan, China for the 5 year period 2012-2016. This work is all freshwater and focusses on a range of species, including the Yangtze River mussel Solenaia oleivora, the northern snakehead Channa argus, and fishes of the genus Schizothorax on the Qinghai Tibet Plateau.

Work in India

In collaboration with colleagues at the Suganthi Devadason Marine Research Institute in Tuticorin I am working on the native green (Perna viridis) and introduced brown (Perna perna) mussels that form an important fishery in southern India. We are interested in a range of topics including:

• Comparative ecology of the two species, including the condition cycles of the two mussels at different sites as a function of the short fishing season (typically December to March).
• Ecological interactions between the mussels and why the invasive brown is so well established in the territory of a supposed super-competitor, the Asian greenshell mussel.
• Possible hybridisation between the two species and the status of the so-called parrot mussel.