This map shows the results of the MBCP aquatic assessment. It incorporates several novel aquatic biodiversity features: use of subcatchments as planning units; biasing the selection of required units to healthy subcatchments; and using Marxan to assess the required subcatchments to meet targets.

Results
The smallest and most efficient portfolio of planning units that meets the targets for all aquatic features was determined using Marxan. The selection of these units was biased towards meeting targets in healthy subcatchments. The results show that 28% of Mpumalanga is identified as important for meeting aquatic biodiversity targets (in addition to protected areas). However, not all of this area is in a healthy state. Of the additional required catchments, only 57% are healthy; 30% moderate and 13% modified. This implies that rehabilitation is needed in order to adequately conserve freshwater biodiversity within healthy subcatchments.

The map identifies the ‘irreplaceability value’ of each subcatchment. This refers to the likelihood of any subcatchment being required to meet aquatic biodiversity targets and indicates the options for meeting these targets. The most valuable catchments will always be required and this map serves to help prioritise conservation actions.