Critical Step 1.3.3: Enhancing refugia for taonga species
Lead: David Kelly
Maui Hudson, John Quinn
Declines in water quality coupled with loss of lake-edge habitat (e.g. macrophytes, riparian zones) have degraded habitat quality for culturally-important lake-dwelling species such as tuna (eels), koura (crayfish) and koaro (Galaxiidae). Field investigations indicate the importance of complex littoral habitats for these species and their prey. Field-based evidence exists for restoring degraded habitats in NZ rivers, but not for lakes. We determine the ability of constructed habitat features to enhance indigenous fish species by experimentally testing (i) usage of structures, large wood, bracken bundles etc, (ii) size of features required, and (iii) scalable effects on whole lake abundance. Monitoring of success is aided by the combined use of dual frequency (Didson) acoustic cameras and side-scan sonar technologies. Before-after-control-impact (BACI) designs is be utilised to test the effectiveness of enhanced habitat features on species usage of lake margins and their implications for lake populations. Study sites for lake indigenous fish habitat restoration trials include Lake Moawhitu (Marlborough District) and Wairarapa Moana (Wellington Region).
Links to other critical steps:
CS 1.2.4 Cultural indicators of lake health and resilience
Department of Conservation
Greater Wellington Regional Council
Ngati Koata Trust
Rangitane o Wairarapa
Kahungunu ki Wairarapa
Marlborough District Council
Fish and Game Wellington
Lake Moawhitu, D'Uriville Island, Marlborough.
Kelly D, Waters S. 2017. Lake Oporoa - Options for water quality restoration. Prepared for Horizons Regional Council. Cawthron Report No. 3066. 44 p
Kelly D, Clark D, Hawes I. 2017. Management of cyanobacteria mats in Wellington's Stuart Macaskill Lakes - light shading trials. Prepared for Wellington Water Ltd. Cawthron Report No. 3025. 28 p.