title: Recognising the negative impacts of aquatic weed management: Okawa Bay, Lake Rotoiti case study

authors: Scholes, Paul

abstract: The Te Arawa Rotorua Lakes Programme continues to implement measures to maintain and restore lake water quality in line with trophic level indices (TLI’s) for respective lakes. In Lakes Rotorua and Rotoiti this has also meant not only reducing nutrients to and in the lakes but also managing periodic cyano-bacterial (blue-green) algal blooms.
Restoration measures in the Rotorua and Rotoiti catchments have included land use management efforts to arrest nutrient inputs; diversion of Lake Rotorua waters from entering Rotoiti; sewage reticulation of lakeside communities; and treatment of inflows
with aluminium sulphate (alum). While restoration efforts have produced water quality gains in both lakes, in recent years, cyano-bacterial blooms have occurred in the shallow embayment of Lake Rotoiti, known as Okawa Bay.
These water quality gains have not come without a cost. Submerged aquatic weeds such as Hornwort are an increasing problem in the Rotorua Te Arawa Lakes and significant resources are needed to manage infestations primarily for aesthetic and recreational
amenity. Control of exotic aquatic weed is mostly with application of herbicide. Herbicide treatment leaves a decomposing biomass in the waterbody, potentially increasing the nutrient status.
We examine the impact aquatic weed decomposition has had on Okawa Bay’s nutrient status and the cyano-bacterial blooms over recent summers, and Bay of Plenty Regional Council’s response to reduce localised bloom development.

text: Recognising the negative impacts of aquatic weed management: Okawa Bay, Lake Rotoiti case study The Te Arawa Rotorua Lakes Programme continues to implement measures to maintain and restore lake water quality in line with trophic level indices (TLI’s) for respective lakes. In Lakes Rotorua and Rotoiti this has also meant not only reducing nutrients to and in the lakes but also managing periodic cyano-bacterial (blue-green) algal blooms.
Restoration measures in the Rotorua and Rotoiti catchments have included land use management efforts to arrest nutrient inputs; diversion of Lake Rotorua waters from entering Rotoiti; sewage reticulation of lakeside communities; and treatment of inflows
with aluminium sulphate (alum). While restoration efforts have produced water quality gains in both lakes, in recent years, cyano-bacterial blooms have occurred in the shallow embayment of Lake Rotoiti, known as Okawa Bay.
These water quality gains have not come without a cost. Submerged aquatic weeds such as Hornwort are an increasing problem in the Rotorua Te Arawa Lakes and significant resources are needed to manage infestations primarily for aesthetic and recreational
amenity. Control of exotic aquatic weed is mostly with application of herbicide. Herbicide treatment leaves a decomposing biomass in the waterbody, potentially increasing the nutrient status.
We examine the impact aquatic weed decomposition has had on Okawa Bay’s nutrient status and the cyano-bacterial blooms over recent summers, and Bay of Plenty Regional Council’s response to reduce localised bloom development.

year: 2015

title: Polynesian settlement of New Zealand and the impacts of volcanism on early Maori society: An update

authors: Lowe, David J.

subjects: Polynesian settlement

abstract: Presents an overview of the timing of Polynesian settlement in New Zealand, discussing the application of tephrochronology and rat and avian bone dating to the problem. The impacts of volcanism on early Maori society are examined, including the catastrophic impacts of the Tarawera eruption of 1886.

text: Polynesian settlement of New Zealand and the impacts of volcanism on early Maori society: An update Presents an overview of the timing of Polynesian settlement in New Zealand, discussing the application of tephrochronology and rat and avian bone dating to the problem. The impacts of volcanism on early Maori society are examined, including the catastrophic impacts of the Tarawera eruption of 1886.

year: 2008

title: To report or not to report? Understanding the impacts of reporting decisions for family and sexual violence in Aotearoa New Zealand

authors: Cording, Jacinta

abstract: Most victims of family violence (FV) and sexual violence (SV) do not report their criminal victimisation to police, but instead their experiences remain part of the ‘dark figure of crime’, or the proportion of actual crimes committed that remain officially unrecorded. The gap between victimisation and reported victimisation has a number of broad consequences for the policies and practices of government.
In this report we combine New Zealand Crime and Victims Survey (NZCVS) and other Integrated Data Infrastructure (IDI) data to consider two broad questions. First, what individual, community and offence-related factors predict non-reporting of FV and SV offences to Police (RQ1)? Second, is reporting or not associated with differences in wellbeing outcomes (RQ2)? Our analyses help to contextualise research and policy that relies on reported crime, and to identify areas where, as a result, reporting-associated policy responses may have potential shortcomings.

text: To report or not to report? Understanding the impacts of reporting decisions for family and sexual violence in Aotearoa New Zealand Most victims of family violence (FV) and sexual violence (SV) do not report their criminal victimisation to police, but instead their experiences remain part of the ‘dark figure of crime’, or the proportion of actual crimes committed that remain officially unrecorded. The gap between victimisation and reported victimisation has a number of broad consequences for the policies and practices of government.
In this report we combine New Zealand Crime and Victims Survey (NZCVS) and other Integrated Data Infrastructure (IDI) data to consider two broad questions. First, what individual, community and offence-related factors predict non-reporting of FV and SV offences to Police (RQ1)? Second, is reporting or not associated with differences in wellbeing outcomes (RQ2)? Our analyses help to contextualise research and policy that relies on reported crime, and to identify areas where, as a result, reporting-associated policy responses may have potential shortcomings.

year: 2025-04-02