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Although spatially explicit decision support tools are widely used in marine conservation planning, only a few studies have used multi-objective approaches to explicitly achieve biodiversity conservation and sustainable use objectives. Here, we use spatial analyses of a comprehensive environment-based classification (developed using Gradient Forest modelling) that summarises spatial patterns in demersal fish composition and turnover in the oceans around New Zealand, and a 20-year record of trawl locations (representing spatial use by fishers), to identify options for biodiversity protection that vary in their relative delivery of conservation outcomes and impacts on fishers. We also compare analyses carried out at a national scale with those generated by aggregating independent regional analyses. The top-ranked 20% of sites identified using fish composition data alone would on average protect 33% of the geographic range of each fish species, but would result in a 58% loss of areas currently fished. By contrast, using the trawl locations as a cost layer reduced average fish protection by 23% in relative terms, but loss of fished areas was almost eliminated. Using different weightings to vary the influence of the trawl footprint, a range of intermediate scenarios were identified that delivered greater fish protection than the fully cost-constrained scenario. However, these intermediate scenarios resulted in greater reductions in the area retained for fishers than the biodiversity optimised scenario. Aggregated regional scenarios delivered lower conservation returns and higher impacts on fisheries than comparable single national scenarios, reflecting the constraining of opportunities for biodiversity protection whilst avoiding overlaps with trawling. While stakeholder MPA design processes often occur at regional scales, our analyses demonstrate the value of considering both regional and national analyses to identify optimal reserve configurations. • Spatial estimates of demersal fish composition and turnover, and trawl fisheries were used to identify options for biodiversity protection. • The analyses were carried out at both national and regional scales. • Exploration of scenarios ranged from complete protection of economic resource use through to maximising the protection of biodiversity. • Regional scenarios delivered lower conservation returns and higher impacts on fisheries than comparable single national scenarios. [ABSTRACT FROM AUTHOR]

We develop a high-resolution conservation prioritization analysis for New Zealand's rivers and streams that simultaneously consider both the present state (representation) of ecosystems, and the prioritization of management actions designed to mitigate ongoing human impacts on their expected future state (retention). As input we used information about the geographic distributions of river ecosystem groups and their compositional similarity, species richness, present condition as compared to their estimated pristine state, and upstream and downstream connectivity. Candidate management actions included riparian planting, establishment of wetlands on tile-drain outflows, and use of riparian buffer strips in plantation forests. The analysis, carried out at a 1-ha resolution for a study area of 22,000 km2 in Southland, New Zealand, demonstrates a credible range of options for management intervention, particularly in lowland streams under serious threat from agricultural intensification. The proposed analysis can be replicated elsewhere for terrestrial, freshwater, or marine systems using publicly available software. [ABSTRACT FROM AUTHOR]

1. Freshwater ecosystems are amongst the most threatened and poorly protected globally. They continue to be degraded through habitat loss, pollution and invading species and conservation measures are urgently needed to halt declining trends in their biodiversity and integrity. 2. During the past decade a suite of decision support tools and computational approaches have been developed for efficient and targeted conservation action in terrestrial or marine ecosystems. These methods may be poorly suited for planning in freshwater systems because connectivity in terrestrial and marine systems is typically modelled in a way unsuitable for rivers, where connectivity has a strong directional component. 3. We modify the conservation prioritization method and software,zonation, to account for connectivity in a manner better suited to freshwater ecosystems. Prioritization was performed using subcatchment/catchment-based planning units and connectivity was modified to have directional upstream and downstream components consistent with the ecology of our target species. 4. We demonstrate this modified method for rivers and streams in the southern North Island of New Zealand. Data included predicted occupancy from boosted regression tree models of species distributions for 18 fish species. The study area covered 2.1 million hectares and included 394 first- to fourth order catchment or subcatchment planning units. 5. Realistic modelling of connectivity had a major influence on the areas proposed for conservation. If connectivity was ignored, recommended conservation areas were very fragmented. By contrast, when connectivity was modelled, high priority conservation targets consisted of entire river basins or headwater subcatchments. 6. The proposed method serves as a starting point for the implementation of reserve selection methods in river ecosystems. [ABSTRACT FROM AUTHOR]

Robust design of Marine Protected Areas in ocean environments is often challenging due to inadequate knowledge of biodiversity patterns, reflecting difficulties in the prediction of species distributions from sampling data that are often sparse or inadequate. Models that combine species and environmental data, such as Gradient Forests (GF), provide one analytical approach to this problem, efficiently combining available information to produce spatial models of species turnover throughout an area of interest. Spatial estimates of species turnover can then be classified to estimate spatial patterns in species composition; however, the performance of GF-based classifications within a conservation planning context has not previously been evaluated. Here we assess the utility for conservation planning (using the software Zonation) of a GF-based hierarchical classification that summarises spatial patterns in demersal fish composition in the oceans around New Zealand. Progressively more complex Zonation analyses assessed the effects of (i) varying the number of classification groups, (ii) adding information describing species turnover, and (iii) adding information describing spatial variation in demersal fish species richness. The best-performing GF-based conservation ranking used layers describing the distributions of 30 classification groups, demersal fish species turnover between these groups, and species richness. Conservation outcomes from this ranking were only marginally less efficient than those from a more conventional ranking that used 217 individual species distribution layers (7% less efficient). This indicates that GF-based classifications may provide a practical alternative for marine conservation planning. Additional advantages arise from the greater ease with which a single classification layer summarising complex biodiversity patterns can facilitate decision-making in participatory stakeholder processes. [Display omitted] • Gradient Forest-based environmental classifications described spatial patterns of demersal fish composition, turnover and richness. • The efficacy of Gradient Forest-based classifications for conservation planning were compared to 'traditional' estimates of individual species' distributions. • A single Gradient Forest-based classification was only marginally less efficient in a conservation planning analysis than a more conventional approach (7% less efficient). • Gradient Forest-based classifications summarise complex biodiversity patterns and provide a practical alternative for marine conservation planning. [ABSTRACT FROM AUTHOR]