Summary
A mass mortality of mangroves occurred in the Kosi estuary in 1965. Events leading up to the mortality were investigated and it was concluded that flooding of the estuary following upon closure of the mouth for five months was responsible. The existing distribution of mangroves, both dead and alive, was recorded and the percentage survival of the various species was determined by means of counts. It was found that mangroves on high ground, chiefly Lumnitzera racemosa Willd., had survived. It appeared that Bruguiera gymnorrhiza (L.) Lam. would probably become the dominant mangrove in the intertidal zone in the future, although Avicennia marina (Forsk.) Vierh. and Rhizophora mucronata Lam. would not disappear from the estuary.