Fish recruitment and habitat use

Many fish move around different parts of the catchment depending on the stage of their life-cycle, and understanding the location of key characteristics of important habitats is key to sustain fish populations. The biotic composition of fish communities in lowland New Zealand has changed over the last few decades due to the invasive abilities of several introduced species which are now widespread and abundant in lowland aquatic environments throughout New Zealand.

Current projects

LERNZ researchers are collaborating with Waikato Regional Council to understand the natal origin of and habitat use by fish in different habitats of the lower Waikato River basin using otolith microchemistry. We are also analysing macroinvertebrate communities that develop in or colonise inundated floodplains, as potential food for fish opportunistically utilising these habitats.  In addition, LERNZ researchers are investigating the generation of zooplankton from floodplain soils and their potential contribution to the nutrition of migrating whitebait. This work is part of an ongoing relationship with the University of Concepción to understand factors affecting the recruitment of Galaxias maculatus.

Contact: Kevin Collier

Completed projects

LERNZ researchers have investigated the use of inundated floodplain habitats by fish and the associated zooplankton communities which generate in these environments and provide a potential food source for larval fish. This work has highlighted the use of floodplain areas for spawning by invasive species and the need to control connectivity during inundation to limit opportunities for spawning.

  • Górski, K.; Collier, K.J.; Hamilton, D.P.; Hicks, B.J. 2014. Lateral interactions of fish and shrimps with off-channel habitats in a large river-floodplain system: the role of flow and temperature dynamics. Hydrobiologia 729: 161-174.

  •  Wu, N.; Górski, K.; Daniel A.J. 2013. Abundance of larval native and nonnative fishes in floodplain habitats of the lower Waikato River, New Zealand. Inland Waters 3: 359-368.

  • Górski, K.; Collier, K.J.; Duggan, I.C.; Taylor, C.M.; Hamilton, D.P. 2013. Connectivity and complexity of floodplain habitats govern zooplankton dynamics in a large temperate river system. Freshwater Biology 58: 1458-1470.