Types of coral reefs, ecology and biodiversity index from Hadhramout waters, Gulf of Aden, Yemen

الملخص EN

The present study was carried out to identify the types of coral reefs; and to highlight the importance and biodiversity index for these species ecology from Hadhramout waters, Gulf of Aden.

Environmental factors were taken only in Burum and Khelf sites: oxygen dissolved, water temperature, pH, salinity, turbidity and sedimentation.

Qualitative survey was done at nine sites in the coastal waters: Husihasa, Jelkha, Burum , Khelf, Al-Quran, Ras Qusiayr, Ras Sharma, Ras Baghashawa and Sharma Island during the period from 2015 until 2016.

At each site, all scleractinian coral species were observed using scuba dives.

The survey of sampling was taken using a 50m belt transect line technique.

The results showed that there were no significant differences (P>0.05) between Burum and Khelf site regarding the environmental factors.

In Burum site, the maximum value of sedimentation which was sunk on coral reef was 7.89 g compared to 5 g in Khelf site.

In all sites, the types of coral reefs found: Turbinaria, Leptoseris, Coscinaraea, Cycloseris (fungia), Acanthastrea, Porites, Parasimplastrea, Montipora, Psmmocora, Anomastraea, Siderastrea, Astreopora, Blastomussa, Favites, Platygyra, Leptoria, Acropora, Goniastrea and Pavona.

Generally, the type of Acropora was more available in all sites compared to other type of coral reefs.

The biodiversity index was the best in Burum ( J= 0.94) followed in Ras Qusair ( J= 0.91) compared to other sites.

From the results, it can conclude that in general the type of Acropora was more obtainable on the Island of Maqrugha (40%) and Yelkha (27%) compared to other sites.