Wetlands Ecology and Management

, Volume 21, Issue 3, pp 157–164 | Cite as

Palau’s taro fields and mangroves protect the coral reefs by trapping eroded fine sediment

  • Shirley Koshiba
  • Meked Besebes
  • Kiblas Soaladaob
  • Adelle Lukes Isechal
  • Steven Victor
  • Yimnang Golbuu
Original Paper

Abstract

Sedimentation is one of the biggest threats facing coral reefs, not only in Palau, but everywhere in the world where there are reefs within reach of river plumes. Due to Palau’s largest island of Babeldaob’s steep topography, high rainfall, and highly erodible volcanic soil, erosion has been exacerbated by recent increases in land-use. Studies have documented the negative impacts of the resulting sedimentation on coral reefs around Babeldaob. Similar studies have shown that mangroves can trap about 30 % of the fine eroded sediment from land. This paper documents the filtering effects of cultivated wetland, namely that of taro (Colocasia esculenta) fields, which are natural wetlands used to grow taro, a source of starch for the population. A 4-month long field study was conducted to quantify the sediment accumulation rate for three different types of taro fields and to determine their sediment trapping efficiency. The results showed that the taro fields have the capacity to trap up to 90 % of sediments. We suggest that the sediment trapping capacity of mangroves and taro fields mitigated the negative impacts of soil runoff on coral reefs around Babeldaob while the island was being inhabited by early Palauans for many generations.

Keywords

Sedimentation Taro field Mangrove Coral reefs Sustainability Palau 

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Copyright information

© Springer Science+Business Media Dordrecht 2013

Authors and Affiliations

  • Shirley Koshiba
    • 1
  • Meked Besebes
    • 2
  • Kiblas Soaladaob
    • 3
  • Adelle Lukes Isechal
    • 1
  • Steven Victor
    • 4
  • Yimnang Golbuu
    • 1
  1. 1.Palau International Coral Reef CenterKororPalau
  2. 2.Belau National MuseumKororPalau
  3. 3.United Nations Joint Presence (GEF-SGP)KororPalau
  4. 4.The Nature Conservancy, Palau Field OfficeKororPalau

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