Native fish in Hawke's Bay: development and application of the river values assessment system (RiVAS and RiVAS+)

Abstract

The second application of the River Values Assessment System (RiVAS and RiVAS+) for native fisheries value was made in the Hawke’s Bay Region. Of 16 rivers or river clusters evaluated, four were considered of national significance, namely the Tukituki, Ngaruroro, Tutaekuri, and Wairoa; the remainder, except the Napier Coast cluster which is ‘local’, are of regional significance. Data for nine out of ten indicators were provided from modelling undertaken by Cawthron Institute using a variety of databases including the NZFFD and FENZ; the expert panel then checked the modelling results and adjusted where appropriate based on local knowledge, and it populated the Population Stronghold indicator. The RiVAS+ methodology was also applied to assess future potential value. Of the 16 rivers or clusters, eight altered their sum total score, all in a positive direction. The Tukituki, Karamu and Napier Coast all shifted most but still remained in their same importance categories. The interventions most frequently identified for enhancing native fishlife value (with the number of times it was identified across all rivers given in brackets) were: Enhance Water Quality – remove/fence out stock (6) (but noting this intervention for Hawke’s Bay is mostly around protecting Inanga spawning sites), and Enhance Water Quality – reduce sediment input (3).