Professor Brendan Hicks

Ecology of Native and Pest Freshwater Fish

Qualifications: MSc Auckland, PhD Oregon State

Personal Website:

Research Interests

Quantitative ecology of freshwater fish; otolith microchemistry and fish life histories; lake ecosystem function; stable isotopes in aquatic food webs.

Forest management and fish communities

My doctoral research in the Oregon Coast range was in the fish ecology of forest streams (Book chapters: Hicks et al. 1991, 311 citations; Refereed journal articles: Hicks et al. 1991, 157 citations; Hicks and Hall 2003, 33 citations) and I have capitalised on this experience, resulting in a recent collaboration with Scion and Ph.D. graduation (Brenda Baillie). This research has looked at the role of geomorphology in structuring stream fish populations, especially the contribution of large woody debris. My comprehensive knowledge on this topic has resulted in three invited book chapters (Hicks et al. 1991, Hicks 2002, Hicks et al. 2004). This work has contributed to forest management rules guiding best practice and protection of streams in managed forests.

Ecology of freshwater fish

Stable isotopes of carbon and nitrogen provide signatures through aquatics food webs that determine the trophic base and nutrient flows in stream and lake ecosystems (Journal article: Rounick and Hicks 1985, 61 citations, Book chapter: Hicks et al. 2010). I have produced a number of studies that investigate food web relations streams and lakes, defining the energy sources in pastoral and forested Waikato streams (Journal article: Hicks 1997, 76 citations). My research in Alaska showed the importance of marine-derived nitrogen from spawning coho salmon to their rearing juveniles (Journal article: Hicks et al. 2005, 70 citations), and I stable isotope knowledge contributed to weta ecology (Journal article: Wehi and Hicks 2010). I have used this experience to guide a number of students in the use of stable isotopes (PhD: Blair, Parkyn, Pingram, West; MSc: Blair, Hailes, Klee, McBride, Osborne, Riordan, Watene), and I hold the Directorship of the Waikato Stable Isotope Unit, which is a successful business unit within the Faculty of Science and Engineering (FSE). The operation of this unit permits low-cost analyses of stable isotopes throughout the Faculty and produces a consistent stream of external commercial income.

A metabolic theory of ecology is a cornerstone of understanding the function of fish and aquatic ecosystems. My research in fish ecology has led to the development of temperature-corrected metabolic model for nutrient excretion by carp (Journal article: Morgan and Hicks 2013). I initiated this work and guided postdoctoral researcher Morgan.

Quantitative estimation of fish abundance

I began my research in the field of estimation of fish abundance by developing the systematic and quantitative use of drift diving (Journal article: Hicks and Watson 1985), a direct counting technique whereby snorkel divers drift in rivers to make direct counts of salmon and trout. At the same time, I develop my skills in wading electrofishing, which is a complementary technique for estimating fish populations in wadeable streams (Journal article: Hicks and McCaughan 1997, Hicks 2003). With Masters students, I extended these techniques to include night-time spotlight counts of large, stream-dwelling galaxiids in the first quantitative application of spotlighting in New Zealand (Journal article: McCullough and Hicks 2002). The advantage of spotlighting over netting and electrofishing is the minimal disturbance of vulnerable native fish populations. Most recently, I have developed quantitative boat electrofishing in New Zealand (Conference proceedings: Hicks et al. 2006), and my team continues to operate the only electrofishing boat in the country. I have used a combination of graphical information systems (GIS) skills, statistical analyses of fish abundance, and systematic application of multiple captures to produce a unique quantitative view of fish abundance New Zealand lakes and rivers. These techniques have produced the first rapid, simple, analyses of complete fish communities in nonwadeable habitats New Zealand. The services of our electrofishing boat and its qualified team continue to be in demand for many on-going contracts with external clients, most of which results in internally reviewed client reports.

Tracing fish life histories through otolith microchemistry

I was instrumental in the use of laser ablation coupled with mass spectrometry to investigate the life histories of freshwater fish through the microchemistry of otoliths, a small calcium carbonate structure in the fish’s head that is analogous to human ear bones. I began this work in collaboration with GNS in Lower Hutt (Journal articles: Baker and Hicks 2003, Hicks et al. 2005a), which I have continued through student research (Journal articles: Blair and Hicks 2012, Tana and Hicks 2012). This work has led to commercial contracts with the Bay of Plenty Regional Council that supported a Masters student (Riceman) and on-going funded research of the impacts of the Lake Rotoiti diversion wall (Contract reports: Blair and Hicks 2009, Hicks et al. 2011). Otolith microchemistry of Antarctic toothfish is the current research topic of Ph.D. student (Tana). This research will investigate to spawning stock identification and improved species’ management.

Remote sensing of water quality in lakes

The most recent development of my research team has been to apply remote sensing to investigate water quality of lakes. This technique can be widely applied using archival satellite images, and can produce accurate spatial measurements of chlorophyll (Allan et al. 2011) and suspended sediment concentrations (Hicks et al. 2013), and surface water temperature. We have automated these techniques in collaboration with staff from the Department of Geography, Tourism and Environmental Planning and with financial support from the Waikato Regional Council. During the course of this research we have supported a Masters student (Allan) and a Ph.D. student (Ashraf), and we initiated a GIS laboratory report research within the FSE. The skills we have developed have resulted in external contracts (Contract reports: Ashraf 2007, 2008, 2009), and our GIS research supports research of the UoW Antarctic programme and NIDEA. I have established a GIS laboratory with a GIS expert, Lars Brabyn, of FASS.


Biology; Environment Issues; Natural Resources; Statistics

Freshwater ecology Freshwater fish

Recent Publications

  • Li, W., Zhang, T., Hicks, B. J., Zhang, C., Li, Z., & Liu, J. (2019). Neutral effects of turbidity across a gradient of vegetation density on the predation of juvenile mandarin fish (Siniperca chuatsi). International Review of Hydrobiology, 104(5-6), 99-105. doi:10.1002/iroh.201601848

  • Baillie, B. R., Hicks, B. J., Hogg, I. D., Van Den Heuvel, M. R., & Kimberley, M. O. (2019). Debris dams as habitat for aquatic invertebrates in forested headwater streams: A large-scale field experiment. Marine and Freshwater Research. doi:10.1071/MF18216

  • Tempero, G. W., Hicks, B. J., Ling, N., Morgan, D., Daniel, A. J., Özkundakci, D., & David, B. (2019). Fish community responses to invasive fish removal and installation of an exclusion barrier at Lake Ohinewai, Waikato. New Zealand Journal of Marine and Freshwater Research, 53(3), 397-415. doi:10.1080/00288330.2019.1579101

  • Kusabs, I. A., Hicks, B. J., Quinn, J. M., Perry, W. L., & Whaanga, H. (2018). Evaluation of a traditional Māori harvesting method for sampling kōura (freshwater crayfish, Paranephrops planifrons ) and toi toi (bully, Gobiomorphus spp.) populations in two New Zealand streams. New Zealand Journal of Marine and Freshwater Research, 1-23. doi:10.1080/00288330.2018.1481437

Find more research publications by Brendan Hicks

Contact Details

Room: R.2.14
Phone: +64 7 838 4661
Cellphone: +64 21 832 287