Meanwhile, the Iban and the Embaloh ethnic groups in the upper and middle reaches of the river obtain much of their livelihoods from farming, rubber production, fishing, and gathering non-timber forest products, including honey. The Malay live in the downstream part of the river and generally become fishers, as well as earning income from rubber gardening and forest honey.
Each ethnic group has its own traditional systems and land-use classifications used to manage their resources and landscape. The Iban people, for example, call their landscape menua, which generally includes several land-use categories: sacred sites (for example, ancestor graves, former longhouse sites, community-protected forests); communal property (such as communal forests for NTFP gathering and hunting, communal lakes for fishing); and household agricultural areas that include swidden cultivation fields and mixed gardens.
Customary rules are used to manage the menua, and traditional rites are conducted before each activity (for example, before planting, before harvesting and after harvesting) to avoid bad luck and to seek blessings from the ancestors.