Defining a zoning problem.

The following information is adapted from Serra-Sogas et al. 2020 and Grantham et al. 2013. Defining a zoning problem can be broken down into seven steps. These steps are specific to setting up a Marxan with Zones planning framework, and are separate to a broader planning exercise that is an iterative process. See "a framework for systematic conservation planning".


THE STEPS.  

Step 1. Identify goals and objectives

Step 2. Identifying compatibilities and incompatibilities

Step 3. Defining number of zones needed to meet the objectives

Step 4. Identifying feature data based on objectives

Step 5. Identify costs based on objectives

Step 6. Defining the relationship between zones, features and costs

Step 7. Defining the spatial relationship between zones

STEP 1. IDENTIFY GOALS AND OBJECTIVES.  

As with any systematic conservation planning exercise the first step is to explicitly define what you are trying to achieve. What are the different objectives within your planning region? What are the different zones? Lets explore a hypothetical example from Raja Ampat in Indonesia.

Located on the north-western tip of Papua, eastern Indonesia, Raja Ampat consists of nearly 1500 islands and encompasses an area of over 4.5 million hectares. Sitting in the epicenter of the Coral Triangle, Raja Ampat contains the world’s most biodiverse coral reefs and is a global priority for conservation. Ecological surveys in the Raja Ampat archipelago have recorded 1320 species of coral reef fish and 553 species of scleractinian corals which is around 75% of the world’s total. The region is also important for many species of marine mega fauna including 16 species of cetacean, dugong, and three species of turtles (Grantham et al. 2013).

Conservation
Recreation
Fishing
After discussion with multiple stakeholders in the region, the spatial planners were able to identify the goals of the region, and turn these into quantifiable objectives or targets.

STEP 2. IDENTIFYING COMPATIBILITIES AND INCOMPATIBILITIES BETWEEN OBJECTIVES.  

Some goals and objectives might be compatible, while others might be in opposition.
In this example, conservation and fisheries objectives are incompatible because fishing activities may cause significant negative impacts to natural resources (e.g., habitat damage, stock depletion). Recreation activities, such as scuba diving tourism, tend to have less of an environmental impact, but may still result in environmental damage (e.g., trampling, anchor damage, fuel/oil spillage) that can hinder conservation outcomes. Yet recreation and tourism activities often depend on healthy environments, and when managed well, these activities can contribute to the conservation of natural environments. Conservation and recreation objectives are therefore ‘somewhat compatible’ here, although it is recognized that there should be some areas where no human activities are allowed to ensure exclusive biodiversity conservation goals are achieved. Likewise, fisheries and recreation objectives are identified as ‘somewhat compatible’ but given that these activities may sometimes conflict with one another, separate zoning allocations for these activities is desirable.

STEP 3. DEFINING THE NUMBER OF ZONES.  

Based on the information outlined above, a zoning framework with three management zones is identified for Raja Ampat. The zones differ based on their restrictions on human activities.

STEP 4. IDENTIFYING FEATURE DATA BASED ON OBJECTIVES.  

In this example, ecological data may be used to represent biodiversity features, such as benthic habitats, coastal landforms and marine species. Human use data could take the form of recreational activities (e.g., surfing, diving, recreational boat mooring and shipwrecks) and fishing activities (e.g., trolling, shore-based fishing, etc.).

STEP 5. ASSIGNING COST (OR COSTS) BASED ON OBJECTIVES.  

This example different costs could be assigned to each zone based on the activities allowed in the zones. For example: planning unit area (Zone 1), distance to shore (Zone 2) and total fisheries catch (Zone 3).

STEP 6. SPECIFYING THE RELATIONSHIPS OF ZONES WITH FEATURES AND COSTS.  

As per step 1, targets at the planning region level have already been specified for each objective.
It is also possible to use zone specific targets, but for simplicity, these are not applied in this example. Instead, specific zone contributions are defined according to the permitted activities and their influence of different objectives. In this case, some feature targets could be achieved across a combination of zones, where some zones contribute more than others at meeting specific targets. For example, areas designated as partial protection zones will contribute 100% to meeting targets for recreational features, and 20% to meeting conservation feature targets. If important habitats are placed in Zone 3, we assume they may be severely impacted by human activities and so we do not consider habitats or species in that zone towards achieving our conservation targets.
More than one cost can be applied to each zone. We use a binary classification to organise the information where a 1 means the cost should be considered in that zone, while a 0 means it is not relevant in zone. In this scenario, planning unit area cost is only applied in Zone 1 to minimize the cost associated with monitoring and managing large amounts of conservation areas. Fisheries catch cost is applied in Zone 1 and Zone 2 because no fishing activities are allowed in either of each zone. Finally, the inverse distance to shore cost is applied in Zone 2 and 3 to encourage planning units found near shore to be assigned to either of the two zones, given that nearshore areas are generally easier to access for fishing and recreation.

STEP 7. DEFINING THE RELATIONSHIPS BETWEEN ZONES.  

To minimize conflict between conservation and fisheries, the spatial configuration between zones is set up to encourage spatial separation between the high protection zone (Zone 1) and the multi-use zone (Zone 3). This is achieved by calibrating the zone boundary cost to encourage the high protection zone (Zone 1) to be buffered by the partial protection zone (Zone 2).
Hypothetical zoning allocation for Raja Ampat, letters represent different locations within Raja Ampat.

FOR MORE INFORMATION.

Much of the information presented here was adapted from:

Serra-Sogas N., Kockel A, Williams, B., Watts, M., Klein, C., Stewart, R., Ball, I., Game, E., Possingham, H., & McGowan J. (2020). Marxan with Zones User Manual. For Marxan with Zones version 2.0.1 and above. The Nature Conservancy (TNC), Arlington, Virginia, United States and Pacific Marine Analysis and Research Association (PacMARA), Victoria, British Columbia, Canada. https://marxansolutions.org/wp-content/uploads/2021/07/MarZone_User_Manual_2021.pdf 

Grantham, Hedley S., Vera N. Agostini, Joanne Wilson, Sangeeta Mangubhai, Nur Hidayat, Andreas Muljadi, Chris Rotinsulu, Meity Mongdong, Michael W. Beck, and Hugh P. Possingham. "A comparison of zoning analyses to inform the planning of a marine protected area network in Raja Ampat, Indonesia." Marine Policy 38 (2013): 184-194. http://dx.doi.org/10.1016/j.marpol.2012.05.035