Ecology and floristics of higher marine fungi of Ethiopianrncoastal I'laters (at Nitsiua) of the Red Sea I'las studied fromrnSept., 1986 to Nay, 1987. 1100d and pneumatophores of Avicenniarnmarina (mangrove) swetienia mhagoni (mhagoni) and Fagusrnsylvatica (fagus) were used as baiting substrates. NangrovernsUbstrate submerged in the sea and driftwoods from Hamlay Desietrnwere the main materials on which the study was focused. Besides,rnthe study included supportive data from environmental parametersrnsuch as temperature, pH, salinity, secchi disc depth, dissolvedrnIrnoxygen, and wood weight and strength losses.rnThe occurrence of the fungi on the test wood blocks inrnrelation to the environmental parameters and their selectiverneffect on the test wood blocks is discussed. The environmentalrnparameters mentioned above along ~Iith ecological factors such asrnheavy sediments in the water, etc. account for the occurrence ofrnthe fungi.rnThe fungal decay rate on each substrate and 3 sites werernstudied in terms of weight and strength losses. Among the timberrnspecies mhagoni and fagus ~ere found to be the most susceptiblernand resistant species respectively.rnbe moderately resistant.rnNangrove wood was found tornMarine fungi colonizing both test wood blocks in three sitesrnand driftl-lOods in one site are listed and most of these arerndescribed and illustrated. Forty nine species of fungi werernisolated and of which Periconia prolifica, cirrenalia tax. sp.rnand Culcitalna acrospora on test wood blocks and Periconiarnprolifica,rndr i ftl-lOodsrnLuhlorthia sp. I, Gnomonia sp.rnwere dominant species.rnand ZaleriQO sp. onrnIn all, 51 species are recorded on wood substrates collectedrnfrom Mitsiua. Out of these 9 species ~Iere found growing only onrntest wood blocks and 30 species on driftwoods. The remaining 13rnspecies were recorded on both these substrata. Of the totalrnfungal taxa recorded, 22 species belonged to Ascomycotina, 1 tornBasidiomycotina and the remaining 28 species to Deuteromycotina.rnThe following 11 species I viz. (Ascomycotina) QJdympsphaeriarntax. SP'I '!:!fllosarph,el.a tax. SP" al1d unidentified ut'litunicaternfungus, (Deutcromycotina) cirrenaliq tax. sp., .Qi);U.QQ.Qqoi!Jm tax.rnSP'I l!.gJosynnema av!cElnn.t~ gen. et SPI nov., J;driella;.tax, sp'.,rnLasiodiploiqia tax. sp. I unidentified pycnidial"fltlgu~ (rnunidentified hyphomycetous fungus and unidentified ' 'fuyceli~rnsterilia are ne~l to marine mycocommunity.rnOf the total collections I 35 species are 9b1ig'atEi lfoiarillerntaxa. 50 species are ne~l records to the Red Sea in pailffi'icularrnand 17 species to the Indian Ocean in general. All of. ~h~nl a~ernnel1 to the Ethiopian coast and are additibns to our knoil;edge onrnthe mycoflora of Ethiopia. 'I'heso findingi; also raisedth~ numberrnof fungi colonizing AviQ.on llIarin.Jl from 7 to 27.rnThe discoverier. suggest that the Red Sea in generaI'falldthernrnmangrove vegetation in particular support great numhers,:of ,fungalrnspecies. Also I the fung i along with other microbes i;111d"marillernborers are organisms that are responsible for the degradatioJ ofrnmangrove and othe,r wood substrates in setl ~later.