Figure 1.
The study region comprising the South African section of the Benguela and the Agulhas Bank ecosystems (hatched area).
The outer boundary of the study region is the South African exclusive economic zone.
Table 1.
Features used in the design of pelagic protected areas in the southern Benguela and Agulhas Bank ecosystems.
Figure 2.
Oceanographic features used in the design of pelagic protected areas.
(a) seamounts and shelf break, (b & c) chlorophyll a, (d) frequency of upwelling eddies and filaments, (e) frequency of downwelling eddies and filaments, (f) retention.
Figure 3.
Biological processes used in the design of pelagic protected areas.
(a) and (d) copepod biomass, (b) and (e) anchovy densities, (c) and (f), sardine densities.
Figure 4.
Species richness of key fisheries species and species of conservation concern.
(a) eight fisheries species based on density distributions, (b) five pelagic breeding bird species based on breeding foraging range, (c) seven species caught as by-catch (three seabirds, two turtles and two sharks) based on catch rates. Density distribution and catch rate values were converted into presence-absence data with any value >0 recorded as present.
Figure 5.
Selection frequencies for two scenarios.
The selection frequency is the number of times a particular planning unit was selected across 1000 runs and is used as an indication of conservation importance. For each planning unit (candidate area for selection) the value represents the percentage of 1000 repeat runs in which it was selected. Both results were based on the same targets except that (a) had targets representing different time periods for chlorophyll a (monthly), copepods (yearly), anchovies (yearly) and sardines (yearly), (b) had targets based on the averaged values, for the full periods of data availability, for chorophyll a, copepods, anchovies and sardines and (c) planning units that have a selection frequency value one standard deviation higher from the mean selection frequency with targets representing different time periods.
Figure 6.
The most efficient protected area solutions for three scenarios.
(a) and (b) had targets of the same size but representing features with data aggregated over different time periods. For (a), values for chlorophyll a were monthly, copepods yearly, anchovies yearly and sardines yearly. For (b), values for chorophyll a, copepods, anchovies and sardines were averaged over the entire periods of data availability. Boundary lengths, which help to determine the compactness of the area configurations, were the same in parts (a) and (b). For (c), boundary lengths between planning units were longer offshore than inshore to produce solutions with more compactness offshore.
Figure 7.
Proportion of feature protected when selections were based on data from different time periods.
Dark gray lines show level of representation in best solutions when targets were set for chlorophyll a (monthly), copepods (yearly), anchovies (yearly) and sardines (yearly). Light gray lines show level of representation in best solutions when targets were set for values of these four features averaged over the whole periods data availability (January 2000 to December 2006 for chlorophyll a, 1998–2001 for copepod biomass, 1984–2007 for anchovy biomass, 1984–2007 for sardine biomass). (a) proportion of chlorophyll a protected, (b) proportion of copepod protected, (c) proportion of anchovies protected, and (d) proportion of sardines protected.
Figure 8.
Integrated pelagic and benthic protected area design.
Benthic data included two biodiversity surrogates used as a proxy for benthic biodiversity (a) biozones based on depth classes, and (b) different benthic habitat classes based on geology. Both were used as a basis for designing protected areas for benthic biodiversity. Each biozone had a target of 20% representation in protected areas. (c) different benthic habitat classes had different targets ranging from 30 to 50%. Areas were selected based on a combination of the pelagic features, biozones and benthic habitat map. (d) the selection frequency for the combined benthic and pelagic targets. (e) the most efficient solution for the combined benthic and pelagic targets.