Wetland Assessment and Monitoring Tool (WAAM)

Pre-human baselines for assessing, monitoring and restoring New Zealand’s wetland ecosystems

Wetlands in peril

New Zealand wetlands provide ecosystem (e.g. water quality, recreation), biodiversity (e.g. threatened species) and cultural (e.g. mahinga kai, weaving fibres) services valued at $US40–50,000 ha/p.a.. However, more than 90% of wetlands have been destroyed since initial human settlement, reducing wetland coverage to just 1% of NZ’s land area. Protecting remaining wetlands and their values is a recognised priority internationally, as well as nationally, and in 2014 more than 132 individual community-led projects were actively attempting to restore 896 ha of NZ wetlands. However, efforts to prioritise, manage and report on wetlands are constrained by current monitoring methods, which only consider a narrow range of ecosystem, biodiversity and cultural services and a historical context based only an expert estimate of the 1840 AD wetland condition.

Our aim

Over the next three years (2017-2020) we will develop a tool for ‘wetland assessment and monitoring’ (WAAM) that:

  • provides historic baselines to guide management and protection of wetland ecosystems, and restoration of mahinga kai and other culturally significant taonga species
  • assesses current wetland condition in relation to historic baselines from which state-changes trajectories and tipping points can be identified, modelled and managed
  • allows DOC, iwi, QEII, regional councils and others to monitor land-use impacts and prioritise restoration efforts
  • advances MfE’s State of the Environment reporting and makes progress towards their long-term target that ‘Freshwater ecosystems are healthy and resilient to pressures’
  • supplies attributes for future inclusion of wetlands in the National Objectives Framework for freshwater management, assisting regulators to measure progress.

How will we do this?

Wetlands are dynamic ecosystems, and determining the ‘naturalness’ of a wetland relies on a deep understanding of how its current state sits against its long-term variability in key factors such as hydrology and biological community composition (Fig. 1). Current approaches to defining wetland condition either fail to consider the long-term context, or else use an arbitrary time point (e.g. 1840 AD) to estimate a ‘natural’ reference state. We therefore hypothesise that current wetland condition metrics correlate weakly with the degree of modification of wetlands from their range of natural (pre-human) states.

Figure 1. Wetland condition is currently determined solely from its present state

Figure 1. Wetland condition is currently determined solely from its present state (circles). However, translating this into ‘naturalness’ relies on a long-term baseline of natural variability (green line) against which trajectories following perturbations (e.g. human impacts) can be assessed. The WAAM tool will provide this context, allowing robust ranking of wetlands for conservation prioritisation, and informing on the relative cost/effort required to restore a wetland to a ‘natural’ state.

We will test this hypothesis by comparing present wetland ecosystems with their past states. Our approach of using past wetland condition to enhance monitoring and management is a global first. The innovative use of leading-edge palaeoecological methods (aDNA, charcoal, ITRAXTM core-tracker) and whole biotic community reconstruction represents a novel approach to defining current wetland condition.

By developing new indices for wetland condition based on newly-available statistical techniques that consider the full range of natural variability rather than single baseline states, we will make conceptual advances in the quantification of changes in multivariate composition and extend the potential for palaeoecology to inform and guide ecosystem restoration.

Our palaeoecological-based measure of wetland condition will include a robust sampling strategy that addresses the spatial heterogeneity of palaeoecological proxies within wetlands, and will be applicable to all wetland types. Moreover, it will allow the identification of indicator taxa for wetland condition that will underpin future eDNA-based monitoring of wetland sites.

With specific focus on tracing DNA from culturally-significant taxa (to be determined in consultation with local iwi) our proposal will incorporate Māori-specific interests by: 1) establishing historical contexts for taonga species and mahinga kai, 2) enhancing habitat quality for mahinga kai, and 3) providing a monitoring tool to support economic harvesting of mahinga kai.

 Setting up sampling plots

Figure 2. Setting up sampling plots on a restiad bog, Awarua, Southland.

 Preparing salmon DNA solution

Figure 3. Preparing salmon DNA solution to help monitor potential contamination within the peat core.

Peat core showing lighter coloured degraded wood,

Figure 4. Peat core showing lighter coloured degraded wood, suggesting former presence of trees on the wetland.

Extraction and analysis of ancient DNA

Figure 5. Extraction and analysis of ancient DNA from wetland cores

Key contact

Contact Jamie Wood Jamie Wood
Contact Janet Wilmshurst Janet Wilmshurst

Key collaborators

Olivia Burge, Bev Clarkson and Sarah Richardson (Landcare Research), Hugh Roberston (Department of Conservation)

Funders

Ministry of Business, Innovation and Employment Endeavour Fund (Smart Ideas)