Resilience of a high latitude Red Sea corals to extreme temperature

Our research objective was to expand the very limited knowledgebase pertaining to the ecology of fringing coral reefs in the Gulf of Suez, Egypt. Specifically, determine dominant coral species and investigate why this reef is capable of surviving at such a high-latitude and extreme harsh environment. Data collection included annual reef surveys, randomized quadrat sampling, five permanent video transects and in situ seawater temperature. Of the known Gulf of Suez 35 taxa, only six (Acropora humilis, A. microclados, A. hemprichii, Litophyton arboretum, Stylophora pistillata, Porites columna, and P. plantulata), compose 94% of the reef's coral cover. Coral dominance across species shifted drastically during the study period. However, the six coral dominance remained unchanged, while some decreased others increased. These six coral taxa regularly experience daily changes in seawater temperature and seasonal variations that exceed These extreme temperatures variation and the fact that only six coral taxa dominance remained unchanged, suggest that these corals may have developed a mechanism to cope with extreme seawater temperatures as evidenced by their continued growth and survival over the study period. We speculate that species dominance shift occurred largely as a result of a local oil spill rather than exposure to extreme temperatures. Further scrutiny of these species and the mechanisms by which they are able to thrive is recommended, as they hold the potential to benefit other coral communities as a resilient transplant species and model for understanding coral survivability in extreme environmental conditions.

Fringing Red Sea Corals Survival: Is It Tide or Local Wind?

In this paper, we obtain tidal constituents and discuss observations of tidal and wind variations and its impact on water surface elevation at Zaki’s Reef;a fringing coral reef located in the Red Sea-Gulf of Suez. This manuscript focuses on investigating if tidal forces are playing a key role to keep the area’s unique coral reefs alive and well. Determining the reasons why coral species and community of organisms found here survive despite all stressors is critical, and such information may hold the key to the preservation of reefs elsewhere. Phase and amplitude for 35 tidal constituents were deducted from observations of water surface elevation at the study site (first of its kind). The main tidal constituents based on their amplitudes are: M2, N2, S2, K1, NU2, K2, 2Ns, L2, and MU2. The first five tidal constituents of the aforementioned list are enough to reproduce accurate predictions of tides at this location (R2 variance = 87.54% and RMS = 0.167). The Tidal Form number (0.07) at Zaki’s Reef indicates a fully semidiurnal dominated tidal regime. Moreover, the Sa and Ssa constituents obtained from nearby stations made no improvements on tidal prediction results. Spectral analysis results of the white noise (residuals) from observed water surface elevation are dominated by daily frequency, suggesting that local wind plays a key role in circulation at study site. Local wind generated southerly long-shore and year-round offshore wind stress with a mean of?-0.36 & 0.35 , respectively. The persistent longshore and offshore currents help transport oil patches/spills, from the two nearby ports, away from the reef. Yet, offshore wind stress, pushing water away from the shore, may cause more exposure of the reef to extreme atmospheric conditions. We hypothesize that the repeated reef exposure to the combined effect of tides and offshore wind stress over many years may have played a key role in selecting and then enhancing corals ability, through training, to become more adaptable to those harsh conditions. Training of corals over the years, may have led to the dominance of only six species, out of 35 coral species known to exist in the gulf. Those heat-adopted dominant species can be used to stimulate and revive impacted coral sites elsewhere.