FERG Members

Jane Gosden

Native plant persistence in kettle holes of the eastern South Island

Kettle holes are glacial derived tarns and in the eastern South Island they typically form ephemeral wetlands, a rare and threatened ecosystem. Ephemeral wetlands hold 5% of Aotearoa’s native vascular flora, including many threatened species. Kettle holes are typically numerous in a landscape, and it is not yet known whether managing a single kettle hole is effective in conserving threatened plants or whether an entire network needs to be managed. Furthermore, all kettle holes are embedded in a matrix of pastoral farming or have been part of pastoral farming in the past. Jane set out to firstly map kettle holes (a desktop exercise) to better understand their distribution and land tenure, and then survey as many as she could over the 2023-2024 summer. Jane visited 269 individual kettle holes from Nelson Lakes National Park to near Mavora Lakes in Southland, undertaking plant surveys in each one. Preliminary results have found that kettle holes contain 8% of New Zealand’s vascular flora. In the next part of her project Jane will look to untangle what drivers influence plant communities in kettle holes

• Email: jane.gosden@pg.canterbury.ac.nz
• Research Interests: Botany, rare ecosystems, native species, community ecology, conservation and management, land use changes

Lauren Hitt

Evaluating the impacts of introduced fish species on Kōaro in lake systems

New PhD student Lauren Hitt has been developing a thesis project that examines how the ecology and life history of kōaro differ in lakes with and without assemblages of introduced fish species. This work will incorporate multiple lines of evidence, including otolith-derived growth rates, reproductive parameters, gut contents metabarcoding, and food web analyses. Understanding how the role of kōaro in lakes changes when introduced fishes are present will help identify conservation priorities for kōaro and provide a valuable reference for the biology of native galaxiids and the food web structures of lakes that are free of introduced fish species.

• Email: lauren.hitt@pg.canterbury.ac.nz
• Research Interests: Freshwater fish, food webs, species interactions, lentic systems, Otolith microchemistry, non-native species

Daniel Hernandez

Almost all ecosystems on Earth experience seasonal fluctuations, but we know surprisingly little about their ecological consequences. As seasonal patterns continue to change globally, understanding how species adaptations to environmental seasonality affect community dynamics becomes crucial. Daniel’s project focuses on the effect of environmental fluctuations on temporal community dynamics and stability in freshwater ecosystems. During his PhD, Daniel will analyse global databases and perform experiments to quantify temporal diversity patterns in response to environmental seasonality and predictability.

• Email: daniel.hernandezcarrasco@pg.canterbury.ac.nz
  Research Interests: Community ecology, biotic interactions, metacommunity theory, freshwater ecosystems, R programming, data visualization

Ciara Espiner

Woody habitat utilisation and instream wood requirements of native New Zealand freshwater fish: Implications for river management practices.

Ciara’s research is focusing on how to improve freshwater instream habitat restoration for native New Zealand fish. Through this research, Ciara aims to determine the type and amount of instream habitat that benefits native New Zealand freshwater fish, applying these findings to current and future restoration practices. Ciara is particularly interested in using a life history trait approach, alongside modelling, to compare the role of instream wood habitat for native New Zealand fish and invasive salmonids. Her research is a strong example of interdisciplinary collaboration, bringing together experts from ecology, geomorphology, and engineering.

• Email: ciara.espiner@pg.canterbury.ac.nz
  Research Interests: Freshwater restoration, artificial habitats, management, freshwater fish, modelling

Christina McCabe

Many of the challenges our freshwater systems face are complex, wicked problems. Such obstacles can feature a lack of information about cascading or interconnected effects, and solutions limited by worldviews. Exacerbating the complexity, our natural world is changing as climate change, biodiversity loss, and human impacts transform river ecosystems.
Christina is an interdisciplinary researcher, drawing on ecology, human geography, and political ecology to understand how ecological change in river environments might impact social transformations toward more ecocentric environmental policy. This works involves conceptually examining cross-scale interactions in the social-ecological system using interdisciplinary theories and ideas. She is also investigating individual and collective experiences of ecological change in river environments, and any impact on values and worldviews. Insights into these processes will contribute to driving conservation systems change, informing programmes and policies from community to government scales.

• Email: christina.mccabe@pg.canterbury.ac.nz
• Research interests:  Landscape-scale riverine ecosystem resilience; Social-Ecological Systems transformation; Community engagement and deliberative democracy.

Anthony (AJ) Gillis

Species interactions along marine stress-gradients

Intertidal ecosystems are extremely dynamic, shaped by intense and
everchanging environmental factors, including fresh and saline water,
temperature, elevation, and bathymetry. These habitats apply strong
environmental filters to communities that form in them. Yet, little is known
about how the mechanisms that influence intertidal estuarine and kelp
forest community assembly and their turnover in changing environments.
My research attempt to fill this gap by exploring how intertidal community
composition and species interactions change along gradients through space
and time. From this research we will better understand what factors drive
intertidal community assembly and how this might be altered by climate or
human-driven shifts in ecological context.

• Email: anthony.gillis@pg.canterbury.ac.nz
• Research Interests: Marine ecology, Community ecology, GIS, species interactions, intertidal communities, statistical approaches, global change

Naomi Heller

Interactive effects of non-native fish and environmental conditions on galaxiid demography

The focus of Naomi’s project is to understand the conditions under which trout and non-migratory galaxiids can stably coexist. Her focus is on interactions between disturbance gradients, trout population structure and galaxiid population structure. In the last year, she has started a trout removal experiment in small high-country streams to understand the effects of lower trout densities on galaxiid demography. Removal efforts are only possible thanks to a multi-agency collaboration, and at its current halfway point, we can already see some promising trends

• Email: naomi.heller@pg.canterbury.ac.nz
• Research Interests: freshwater fish, species interactions, invasions and non-native species, climate change, conservation biology.

Gabrielle Koerich

Species distributions are closely linked with the environment, and as such, alterations driven by climate change are expected to affect species’ ranges. Determining how the distribution of species will change in space and time is central to guiding decision-making of conservation actions. Gabrielle is exploring how a warming climate will affect the distribution of terrestrial Antarctic species, as part of the Antarctic Science Platform. First, she is aiming to understand what are the main ecological processes driving biogeographical patterns in Antarctica, to then inform hybrid distribution models to forecast species geographical ranges under novel environmental states.

• Email: gabrielle.koerich@pg.canterbury.ac.nz
• Research interests: species distributions, climate change biology, niche theory, conservation biology

Ignacio Reyes

Anthropogenic climate change is exerting critical pressures on freshwater ecosystems leaving them in an extremely vulnerable state. Understanding how changes to global temperatures and precipitation patterns will alter river ecosystems will facilitate better preservation of this biodiversity. Ignacio's research focuses on community structure of riverine fish and the relationship with flow regimes. Different flow regimes will create alternative assemblages and, thus, climate change-induced changes to flow regimes will have a great impact on riverine fish communities. Ignacio will model the flow-ecology relationship of riverine fish to, then, extrapolate this relationship to future climate scenarios, to unravel how fish assemblages will be under different climate change predictions. This will serve to inform decision making and more effective conservation measures implementation.

• Email: ignacio.reyessainz@pg.canterbury.ac.nz
• Research interests: Climate Change, conservation biology, stochastic and mechanistic modelling, flow-ecology relationships

Martha Jolly

Freshwater biodiversity worldwide is under increasing pressure from a range of human-related pressure. One of the most detrimental is the many invasive fish species, often deliberately introduced, that are contributing to declines in abundance and range of native fishes. In Aotearoa New Zealand, non-migratory galaxiid fishes are highly threatened with 94% of species at risk of extinction. Introduced sports fish (trout) have had a large impact on small endemic NMG populations. One promising tool in the protection of native fish is isolation management, with the deliberate use of barriers to exclude invaders. Martha’s research involves the use of deliberate fragmentation to protect native fish species, without causing extirpation through isolation.

• Email: martha.jolly@pg.canterbury.ac.nz
• Research interests: non-migratory galaxiids, isolation management, population viability, aquatic invasions, freshwater fish

Saskia Brown

Saskia is investigating the effects of aquatic weeds in biodiverse high-country springs. She is using surveys to compare current and past conditions, as very little is known about how the distribution of these weedy plants has changed and what impacts they are having on native freshwater flora and fauna. Saskia has investigated changes in macrophyte community composition from two decades ago and how expansions of non-native species are impacting these compositions. Saskia is also using experiments to gain a better understanding of the impacts.

• Email: saskia.brown@pg.canterbury.ac.nz
• Research Interests: Invasion dynamics, non-native species, conservation ecology, global changes, aquatic plants, species interactions, Potamopyrgus (New Zealand mud snails)

Olivia Reynolds

Factors controlling the distribution of the upland longjaw galaxias –

Olivia Reynolds is a master’s student at the University of Canterbury and is supervised by Angus McIntosh and Nixie Boddy (DOC). The purpose of Olivia’s research is to investigate the distribution of a rare freshwater fish at both a large scale (South Island wide) and at a smaller scale in Te Awa-a-Takatamira / Cass River. This research project is supported by Fish Futures.

• Email: olivia.reynolds@pg.canterbury.ac.nz
• Research Interests: Freshwater fish, species interactions, population dynamics, species distributions, non-native species, braided rivers, conservation

Lucy Coulston

Exploring indigenous empowerment in highly modified systems: A comparative case study of Waituna and Waitarakao coastal lagoons 

Lucy’s research focusses on indigenous empowerment in highly modified systems, through exploring governance, management and mana whenua connection to Waituna and Waitarakao coastal lagoons. This research is exploring socio-ecological systems and trying to understand how extensive land modification and degradation of cultural significant coastal lagoons has affected Kaitiakitanga. This research is being supported by partners Aoraki Environmental Consulting Limited (AECL), Arowhenua rūnaka, Te Ao Marama Incorporated (TAMI) and Awarua rūnaka. Lucy will be conducting interviews with these entities for her data collection.

• Email: lucy.coulston@pg.canterbury.ac.nz
• Research Interests: Mātauranga Māori, governance and management, socioecology, land use changes, freshwater restoration, coastal lagoons

Liam Taylor

The Temporal and Spatial Dynamics of a landlocked Kōaro population in a braided river system

Freshwater ecosystems are becoming increasing degraded, with altered flow regimes and reduced longitudinal and lateral connectivity.  Species with complex or novel life cycles are likely to be the most affected by these changes. Liam’s research focusses on the temporal and spatial dynamics of fish populations with complex life cycles and how these may be affected by global changes. This research is investigating a population that has become landlocked due to extensive anthropogenic dams and looks to understand the dynamics of these more novel populations and their vulnerability to climate change, specifically changes to temperature and flow regimes. Liam is using a Kōaro population in the Te Awa-a-Takatamira / Cass River as his study population and the research project is supported by Fish Futures.

• Email: lta75@uclive.ac.nz
• Research Interests: Freshwater fish, population dynamics, climate and global change, braided rivers, species interactions, community ecology, conservation, non-native species

Jack Anderson

Statistical frameworks for joint species distribution modelling

Jack Anderson began his Master’s program under the supervision of Tadeu Siqueira. He is developing a statistical framework based on Joint Species Distribution Modelling to investigate how imperfect detection influences our understanding of community-environment relationships. Jack is using a dataset on birds and butterflies in Singapore to understand how detection rates can affect ecological relationships.

• Email: jack.anderson@pg.canterbury.ac.nz
• Research Interests: Species distributions, Statistical analysis, R programming, GIS, community ecology

Zoe Hamilton

The contribution of size-structured interactions to food webs underpinning an
extremophile fish

Extreme environmental conditions are increasing in prevalence through the independent and synergistic effects of global change drivers. These ongoing changes may see more species occupying extreme freshwater environments. The New Zealand brown mudfish (Neochanna apoda), found in tree tip-up pools in peat-swamp forests, thrives in highly variable and harsh conditions despite apparent lack of aquatic resource base. Zoe’s research will investigate the food-web structures that support mudfish populations, focusing on cross-ecosystem subsidies and size-structured interactions like cannibalism. Zoe’s findings can enhance the management of brown mudfish and inform conservation strategies for other species in extreme environments as such conditions become more prevalent globally.

• Email: zbh17@uclive.ac.nz
• Research Interests: freshwater fish, food webs, conservation, modelling, global change, community ecology