Ramsar Organization dealing with wetlands has brought out a few adverse effects from the nickel mining operations on the wetlands in the interior regions of New Caledonia. Many wetlands have either been lost or spoiled. Rivers and streams have been choked with tailings from the waste material dumped from the nickel mines. This has resulted in rise in bed levels of the rivers and consequent flooding affecting fertile agricultural lands. Many river delta areas have been affected creating changes in aquatic flora and fauna; the mining effluents are reported to have affected about 40 streams in their middle and lower reaches. Even estuaries and bays are reportedly affected by the “red clay and lateritic sub-soil,” which covers some of the mangrove forests.