IV: Animal Resources Management

Protected Area Effectiveness for Fish Spawning Habitat in Relation to Earthquake-Induced Landscape Change

SHANE ORCHARD[1] [2]' and MICHAEL J. H. HICKFORD[3]

Waterways Centre for Freshwater Management, University of Canterbury and Lincoln University, Christchurch, New Zealand

2Marine Ecology Research Group, University of Canterbury, Christchurch, New Zealand

'Corresponding author. E-mail: This email address is being protected from spam bots, you need Javascript enabled to view it

Incorporating elements of both strategies provide a promising conceptual basis for adaptation to major perturbations or responding to slow change.

INTRODUCTION

For many species, critical life-history phases create obligate habitat requirements. These may be vulnerable points in the life cycle, especially where relatively specific biophysical conditions are required (Lucas et al., 2009). The vulnerability may be associated with both periodic events and longer- term change involving natural and anthropogenic processes (Turner et al., 2003). A particular concern is where human activities reduce the quality or availability of existing habitat unless counterbalanced by compensatory actions, such as the creation of suitable habitat elsewhere (Faith and Walker, 2002). The concept of resilience provides a focus on thresholds in system properties that are important to their persistence (Holling, 1973). In linked socioecological systems it is related to adaptive capacity (Gallopin, 2006) and actual responses to changed hazard exposure and/or sensitivity (Turner et al., 2007). Since resilience assessment is concerned with identifying the conditions required to maintain a desirable state (Gunderson et al., 2010), it may be readily applied to habitat management.

Protected areas (PAs) describe the desired state defined by clear objectives. They are a cornerstone of global efforts to halt biodiversity loss (UN, 2011). The IUCN recognizes six categories of PAs defined by differences in management approaches (Stolton et al., 2013). Category IV PAs aim to protect particular species or habitats (Table 21.1). They are often relatively small and are designed to protect or restore: (1) Flora species of international, national, or local importance; (2) fauna species of international, national, or local importance including resident or migratory fauna; and/or (3) habitats (Dudley, 2008).

Effective conservation involves managing risks yet biodiversity declines are continuing (Butchart et al., 2010). Management effectiveness evaluation is an essential activity to assess the strengths and weaknesses of the protection mechanisms in place and to consider alternatives (Stolton et al., 2007). A key area of focus is the extent to which PAs actually deliver on objectives such as the protection of important values (Hockings, 2003). Under conditions of environmental change, evaluation is especially important to address whether the areas involved are functioning as an effective conservation strategy (Leverington et al., 2010). Various methodologies have been used, many of which were originally developed to support adaptive management of PA sites and systems (Coad et al., 2015). Range shifts are a topic of particular importance since they may undermine the effectiveness of existing PA networks. In this setting, human agency is inextricably linked to the trajectory of the values identified for protection. This may require amendment of the protection mechanism itself to ensure continued performance over time.

TABLE 21.1 Aspects of IUCN Category IV Protected Areas (Dudley, 2008).

Role in the landscape/seascape

Category IV protected areas frequently play a role in “plugging the gaps” in conservation strategies by protecting key species or habitats in ecosystems.

They could, for instance, be used to:

• Protect critically endangered populations of species that need particular management interventions to ensure their continued survival;

• Protect rare or threatened habitats including fragments of habitats;

• Secure stepping-stones (places for migratory species to feed and rest) or breeding sites;

• Provide flexible management strategies and options in buffer zones around, or connectivity conservation corridors between, more strictly protected areas that are more acceptable to local communities and other stakeholders.

Issues for consideration

• Many category IV protected areas exist in crowded landscapes and seascapes, where human pressure is comparatively greater, both in terms of potential illegal use and visitor pressure.

• The category IV protected areas that rely on regular management intervention need appropriate resources from the management authority and can be relatively expensive to maintain unless management is undertaken voluntarily by local communities or other actors.

• Because they usually protect part of an ecosystem, successful long-term management of category IV protected areas necessitates careful monitoring and an even greater- than-usual emphasis on overall ecosystem approaches and compatible management in other parts of the landscape or seascape.

Diadromous fishes have specific habitat requirements across several stages of their life histories, involving both freshwater and marine environments (Gross et al., 1988). In some species, these may be separated by vast distances and associated with significant migrations (Metcalfe et al., 2002). There may be different conservation issues affecting each critical habitat requiring a wide range of management responses (McDowall, 1999). Galaxias maculatus (Jenyns, 1842) or Tnanga’ is a diadromous species currently listed as ‘at risk-declining’ under the New Zealand

Threat Classification System (Goodman et al., 2014). Adult fish are found in lowland coastal waterways with the upstream distribution limited by relatively poor climbing ability (Baker and Boubee, 2006; Doehring et ah,

2012). Spawning occurs in estuarine waterways with the exception of some populations that have become landlocked in lakes (Chapman et ah, 2006). The locations used are highly specific as the result of specialized reproductive behavior associated with the migration of adult fish toward river mouths at certain times of the year (Benzie, 1968a). Spawning events are strongly synchronized with the spring high tide cycle with an apparent association between spawning site distribution and the salinity regime (Burnet, 1965). The majority of spawning sites have been found within 500 m of the inland limit of saltwater (Richardson and Taylor, 2002; Taylor, 2002). In addition, spawning sites occupy only a narrow elevation range located on waterway margins just below the spring tide high-water mark (Taylor, 2002). As tidal heights drop toward the neap tides these sites are no longer inundated at high-water and for most of their development period the eggs are in a terrestrial environment (Benzie, 1968a, 1968b). Egg survival rates are highly dependent on the condition of the riparian vegetation in these locations until hatching in response to high water levels, usually provided by the following spring tide (Hickford et al., 2010; Hickford and Schiel, 2011).

The degradation of spawning habitat has been identified as a leading factor in the species’ decline (McDowall, 1992; McDowall and Charteris,

2006). This has been linked to land-use intensification on coastal waterway margins (Hickford et al., 2010), as is a common trend worldwide (Kennish, 2002). Protection mechanisms must often address contested-space contexts characterized by incompatible activities. Multiple-stressor situations are common with grazing, vegetation clearance, mowing, grazing, flood protection, and channelization being examples that have contributed to degradation (Hickford and Schiel, 2011; Mitchell and Eldon, 1991). Habitat protection is a requirement of national legislation under the Conservation Act (1987) and the Resource Management Act (1991). The implementation relies on the identification of areas for protection enforced by appropriate rules and documented in plans or management strategies prepared under the relevant Acts (Orchard, 2016). In many cases, spatially explicit planning methods (e.g., maps) are used to delineate the protected areas. Although these provide a practical approach to address the conservation objective, they require reliable habitat information. In dynamic environments challenges include recognizing spatiotemporal variance and accommodating it in design of the protection mechanisms used (Bengtsson et al., 2003).

In 2010 and 2011, a sequence of major earthquakes affected the Canterbury region of New Zealand. It included several large destructive events and numerous aftershocks centered beneath the city of Christchurch (Beavan et al., 2012). The magnitude of physical effects necessitated a longterm socioecological response associated with new ecological trajectories and a variety of land-use planning needs. Topographic and bathymetric measurements identified enduring changes in ground levels, especially in the vicinity of waterways (Quigley et ah, 2016). Ecohydrological effects have been a particular focus in light of changed water levels on the landscape (Hughes et ah, 2015), and alterations to estuarine dynamics (Measures et ah, 2011; Orchard and Measures, 2016, 2017). G. maculatus spawning was recorded at locations never previously utilized in comparison to prequake records (Orchard and Hickford, 2016). Vulnerability assessments identified anthropogenic threats at many of these locations and recommended a review of protection methods in the operative statutory plans (Orchard et ah,

2018). This context presented a unique opportunity to evaluate conservation planning options in light of landscape-scale change whilst informing the practical needs of postquake adaptation processes. The objectives of this paper are to (1) evaluate the efficiency and effectiveness of contemporary protection mechanisms, and (2) identify recommendations for conservation planning to address earthquake-induced landscape change.

  • [1] ABSTRACT We studied the effectiveness of spatial planning methods for the conservationof Galaxias maculatus, a riparian spawning fish, following earthquake-induced habitat shift in the Canterbury region of New Zealand. Mapping andGIS overlay teclmiques were used to evaluate three protection mechanismsin operative or proposed plans in two study catchments over 2 years. Method
  • [2] utilized a network of small protected areas around known spawning sites.
  • [3] It was the least resilient to change with only 3.9% of postquake habitatremaining protected in the worst-performing scenario. Method 2, based onmapped reaches of potential habitat, remained effective in one catchment(98%) but not in the other (52.5%). Method 3, based on a habitat model,achieved near 100% protection in both catchments but used planning areasfar larger than the area of habitat actually used. This example illustratesresilience considerations for protected area design. Redundancy can helpmaintain effectiveness in face of dynamics and maybe a pragmatic choice ifplanning area boundaries lack in-built adaptive capacity or require lengthyprocesses for amendment. However, an adaptive planning area coupled withmonitoring offers high effectiveness from a smaller protected area network.
 
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