• remote-sensing;
  • satellite imagery;
  • Mnazi Bay Ruvuma Estuary Marine Park;
  • unsupervised classification;
  • classification accuracy


  • 1.
    Despite the ecological, environmental, and economic importance of mangroves, they are declining at an alarming rate worldwide, mostly as a result of human activities.
  • 2.
    Along the eastern African coast, Mozambique has the largest mangrove area. Fishing and farming are the main economic activities in the area, and people harvest mangrove vegetation for tannins, fuel wood, traditional medicine, boat-building, carpentry, and crafting.
  • 3.
    Landsat 5 TM imagery was used to map the distribution of trans-boundary mangrove areas along the Mtwara–Quirimbas Complex. Results for 1995 and 2005 are presented for the entire coastline and in more detail for the Ruvuma estuary, Quiterajo, Ibo/Quirimba islands, and Pemba Bay. Results were validated with a ground-truthing excursion in 2006, showing an overall thematic accuracy of 73%.
  • 4.
    Total estimated area of mangrove was 357 km2 in 1995 and 368 km2 in 2005, with the small net gain of 3% corresponding to a total gain of 32 km2 and a total loss of 21 km2 over this decade.
  • 5.
    Results suggest that although Landsat TM imagery can be effective in mapping mangrove distribution, caution must be used in inferring its ecological condition. Copyright © 2009 John Wiley & Sons, Ltd.