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Figure from:Zoning Cambodia's First Marine Fisheries Management Area

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contribute to Cambodia’s aforementioned national! targets. The relative percent representation target set for each feature (e.g. coral diversity, fish refuge) was dependent on the extent, importance and/or rarity of the feature, based on its perceived significance to the authors.

Table 2 contribute to Cambodia’s aforementioned national! targets. The relative percent representation target set for each feature (e.g. coral diversity, fish refuge) was dependent on the extent, importance and/or rarity of the feature, based on its perceived significance to the authors.

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Table 1 Conservation targets developed for each zone in the proposed Marine Fisheries Management Area using Marxan with Zones analysis. *Pre-identified areas of >50" percentile. (Watts et al., 2009). The software employs an algorithm called “simulated annealing”, which uses iterative improvement while accepting some bad moves in initial iterations to provide near-optimal solutions for zoning configurations (Ball et al., 2009). This algorithm has a randomisation component and therefore gener- ates a different solution for every run. The study site was subdivided into a grid of 2,324 p anning units, including all areas that may potentially be selected as part of the zoning design. Each p unit measured 100 m x 100 m: no smaller t anning han the features mapped and no larger than would be realistic for management decisions. The Marxan analyses involved running the software 100 times, with every run consisting of a million iterations. Table 2 Zone cost for each zone, given by opportunity costs using sedimentation and fishing pressure as proxies. The higher the zone cost weighting, the less likely the area will be selected for that zone when the particular cost (sedimentation or fishing pressure) is high.
Table 1 Conservation targets developed for each zone in the proposed Marine Fisheries Management Area using Marxan with Zones analysis. *Pre-identified areas of >50" percentile. (Watts et al., 2009). The software employs an algorithm called “simulated annealing”, which uses iterative improvement while accepting some bad moves in initial iterations to provide near-optimal solutions for zoning configurations (Ball et al., 2009). This algorithm has a randomisation component and therefore gener- ates a different solution for every run. The study site was subdivided into a grid of 2,324 p anning units, including all areas that may potentially be selected as part of the zoning design. Each p unit measured 100 m x 100 m: no smaller t anning han the features mapped and no larger than would be realistic for management decisions. The Marxan analyses involved running the software 100 times, with every run consisting of a million iterations. Table 2 Zone cost for each zone, given by opportunity costs using sedimentation and fishing pressure as proxies. The higher the zone cost weighting, the less likely the area will be selected for that zone when the particular cost (sedimentation or fishing pressure) is high.
Fig. 1 Conservation management values and areas of high reef conservation interest from the scoring method. Zones can be designated across many small or a few large areas and still meet the same conserva- tion targets set. The level of clumping influences the effectiveness and ease of zone implementation. Too little clumping results in many small areas in each zone which may not meet minimum size require- ments for species or habitat protection or to act as a productive fishing ground; too many boundaries may also be confusing and cause management challenges. Creating a few large areas from too much clumping, on the other hand, may cause overlaps and conflicts among resource users. Using Marxan with Zones, a sensitivity analysis of the parameter, zone boundary cost, allows the user to explore different levels of compactness. Calibration was conducted and zone boundary cost was set to 1 across all zones. Artisanal fishing pressure was highest around Koh Ta Team to the north of Koh Rong, northeast and southeast of Koh Rong close to Prek Svay and Doem Thkov respectively, between Koh Koun and Koh Rong
Fig. 1 Conservation management values and areas of high reef conservation interest from the scoring method. Zones can be designated across many small or a few large areas and still meet the same conserva- tion targets set. The level of clumping influences the effectiveness and ease of zone implementation. Too little clumping results in many small areas in each zone which may not meet minimum size require- ments for species or habitat protection or to act as a productive fishing ground; too many boundaries may also be confusing and cause management challenges. Creating a few large areas from too much clumping, on the other hand, may cause overlaps and conflicts among resource users. Using Marxan with Zones, a sensitivity analysis of the parameter, zone boundary cost, allows the user to explore different levels of compactness. Calibration was conducted and zone boundary cost was set to 1 across all zones. Artisanal fishing pressure was highest around Koh Ta Team to the north of Koh Rong, northeast and southeast of Koh Rong close to Prek Svay and Doem Thkov respectively, between Koh Koun and Koh Rong
Fig. 2 Marine ecosystem threats: (a) fishing pressure; and (b) sedimentation levels in the Koh Rong Archipelago.
Fig. 2 Marine ecosystem threats: (a) fishing pressure; and (b) sedimentation levels in the Koh Rong Archipelago.
Fig. 3 Initial zonation plan produced from Marxan with Zones in relation to areas of high reef conservation interest. The scoring method is a quick and easy way of informing zoning plans, but is not by itself suffi- cient to develop a zoning plan, particularly when socioeconomic costs are not considered. Systematic conservation planning methods using tools such as Marxan with Zones provide more comprehensive alternatives and allow the user to explore different scenarios using different values of parameters. For example, the zone boundary cost can be adjusted to encourage further separation of conflicting uses; conservation areas can be placed far from Multiple Use Areas. Zones that share compatible management objectives can also be clustered: Conservation Areas can be located next to forested areas, so as to benefit from their buffering effects against terrestrial runoff. solution” from Marxan with Zones, on the other hand, highlighted a few Conservation Areas on the east side of the island because despite high sedimentation levels in the east (Fig. 2), the analysis was constrained by the high conservation targets set for mangroves and seagrass, which were not considered in the scoring method and were mostly located on this side of the island. The area between Koh Koun and north of Koh Rong Sanloem recorded high CMVs, yet was identi- fied as a Community Fishing Area in the Marxan with Zones “best solution” (Fig. 3). This was due to the high to very high fishing pressure in that area, which precluded the Conservation Area zone from this site, as dictated by the high zone cost weighting of fishing pressure for the zone (Table 2).
Fig. 3 Initial zonation plan produced from Marxan with Zones in relation to areas of high reef conservation interest. The scoring method is a quick and easy way of informing zoning plans, but is not by itself suffi- cient to develop a zoning plan, particularly when socioeconomic costs are not considered. Systematic conservation planning methods using tools such as Marxan with Zones provide more comprehensive alternatives and allow the user to explore different scenarios using different values of parameters. For example, the zone boundary cost can be adjusted to encourage further separation of conflicting uses; conservation areas can be placed far from Multiple Use Areas. Zones that share compatible management objectives can also be clustered: Conservation Areas can be located next to forested areas, so as to benefit from their buffering effects against terrestrial runoff. solution” from Marxan with Zones, on the other hand, highlighted a few Conservation Areas on the east side of the island because despite high sedimentation levels in the east (Fig. 2), the analysis was constrained by the high conservation targets set for mangroves and seagrass, which were not considered in the scoring method and were mostly located on this side of the island. The area between Koh Koun and north of Koh Rong Sanloem recorded high CMVs, yet was identi- fied as a Community Fishing Area in the Marxan with Zones “best solution” (Fig. 3). This was due to the high to very high fishing pressure in that area, which precluded the Conservation Area zone from this site, as dictated by the high zone cost weighting of fishing pressure for the zone (Table 2).