Research

FEEDING ECOLOGY


Dugong feeding ecology along the Egyptian Red Sea


This study focused on the popular habitats of dugongs in Marsa Alam and Wadi El-Gemal National Park (WGNP) in the Red Sea off southern Egypt in 2016 and 2017. 


We assessed the abundance of seagrass species, dimensions of feeding trails, grazing rate compared to its relative accessibility, and frequency of feeding trails and estimated the existing dugong population via different trail widths.

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DUGONG GRAZING EFFECT


The grazing effect of Dugong on seagrass: a field experiment at Wadi El Gemal National Park, Egypt.


The grazing effect by dugong on seagrass was experimentally observed for one year in 2016 at the Shams Alam site within Wadi El-Gemal National Park.


Two levels of grazing intensity (low grazing and high grazing) were performed to understand the competition and recovery between the seagrass species and compared to a control area with no grazing.



SHARK PHOTO ID


Photo-identification of the oceanic whitetip shark (Carcharhinus longimanus) at Elphinstone Reef, Egypt, Red Sea.


A photo identification project on the oceanic whitetip shark by SCUBA diving was carried out from Jun 28, 2016, to Jan 5, 2019.


The shape and the white apex of the first dorsal fin were used as main features to identify 105 oceanic whitetip sharks at Elphinstone Reef. Eight individuals were males and 97 were females (male-to-female ratio of 1:13.125).

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DOLPHIN TOURISM IMPACTS


Effects of swim-with-dolphin tourism on the behaviour of spinner dolphins, at Samadai Reef in the Egyptian Red Sea


Behaviour of the spinner dolphins was monitored both on days when tourist boats were present and on days when they were absent using Marcov chain modelling.


Tourist activities affect the transition probabilities between dolphin activity states from resting to milling, or travelling, from milling to travelling or avoiding, and from travelling to avoiding.



NEW RECORD


Evidence of the occurrence of a large dugong in the Red Sea, Egypt


Three feeding trails of a large dugong with a width of 30 cm were recorded at 11 m depth at Marsa Hermez off the Egyptian Red Sea coast on the 23rd of January 2019.


The present results indicate the demonstration of the presence of a large female dugong in the Red Sea and the presence of female dugongs with calves in key habitats.

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DUGONG FEEDING TRAILS


Analysis of Feeding Trails Provides Evidence of the Number of Dugongs Excavating Seagrass at Key Habitats Seasonally in the Egyptian Red Sea.


The aims of the work were: 1. Estimate the temporal and spatial variation of seagrass abundance. 2. Identify the temporal and spatial variation of the feeding trails. 3. Examine a relationship between the dugong muzzle width and total body length using laser photogrammetry technique. 4. Create predictive modeling maps for suitable dugong habitats and calving. 5. Raise awareness of dive guides, snorkeling guides, and local communities. 6. Preparing the first management plan for dugong conservation in Egypt.




DUGONG STATUS


Status of Red Sea Dugongs


Research on dugongs in the Red Sea began with largely anatomical and physiological work on dugongs that were accidentally killed or purposely netted.


Currently, largely due to observations of live dugongs in the wild and to data that can be collected underwater during SCUBA diving, snorkeling, and stranded carcasses.

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DUGONG PHOTO ID


Photo identification of dugongs in Marsa Alam and Wadi El-Gemal National Park, Egypt


Using underwater photo identification, an ID catalog was prepared for the dugongs with records of their occurrence among sites, in the Red Sea, Egypt.


A total of 30 dugongs were recorded at the southern Egyptian Red Sea coast between December 2015 and October 2017, 16 at Marsa Alam and 14 at Wadi El-Gemal National Park.


STRANDED DUGONG CALF


Stranding of a neonatal dugong calf in Wadi El-Gemal National Park: Implications for dugong conservation in Egypt


A male dugong calf of 120cm long was observed in Wadi El-Gemal National Park on September 29th, 2015. It was released back to the sea but was found dead on October 4th, 2015. Photo ID confirmed the individual. The time budget of behavioural activities was recorded before and after stranding.


After stranding, the calf surfaced to breathe, rest more, and travel less. It died 12 days after the first observation on September 22nd. All possible measurements were taken.

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PROF. HAMED GOHAR


The Red Sea Dugong


Gohar (1957) recorded 16 dugongs within 70 km between Hurghada and Ras Gemsha over 14 years. He obtained his specimens using specially made fishing nets.


Gohar (1957) recorded 10 females, six males, and no calves. He studied the anatomy of the dugong. He reported that in males, the distance between the anal and genital opening is approximately 1/7th the total length of the animal while in females the distance between the vulvar and the anal clefts was between 2.5 to 3.5 cm.



DOLPHIN PHOTO ID


Estimation of the abundance of the spinner dolphin Stenella longirostris using photo identification technique in Samadai Reef, Red Sea, Egypt


Dolphins were photographed for individual identification purposes in Samadai Reef, Marsa Alam, Red Sea, between January 2012 and March 2013.



A total of 255 spinner dolphins were identified with a mean identification rate of 45%. A total of 33 individuals (12.9%) were resighted 4 to 8 times, and 131 individuals (51.4%) were sighted only once. Photo identification analysis provided a population size of 567 to 637 dolphins.

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SHARK ECOLOGY


Human impact on the presence of sharks at diving sites, Red Sea, Egypt


The study was carried out between June and November 2008 at Elphinstone, Daedalus, Big Brothers Island, Small Brother Island, Zabargad Island, Rocky Island, and Habili Ali.


Eight species of sharks for a total of 292 specimens were recorded: whale shark (1 specimen), pelagic thresher shark (12), silvertip shark (1), gray reef shark (61), silky shark (2), oceanic whitetip shark (123), whitetip reef shark (5), and scalloped hammerhead (87). The frequency of encounters in Elphinstone is considerably lower than in other study sites.




DOLPHIN BEHAVIOUR


Behaviour of Spinner Dolphin at Sha'ab Samadai, Marsa Alam, Red Sea, Egypt


The behaviour of the Spinner Dolphin Stenella longirostris was studied at Sha'ab Samadai, Marsa Alam, Red Sea. The data were collected from October 2005 until September 2006 using surface observations.


Four objectives were studied: arrival and departure time of dolphins, distribution of dolphin movements within the lagoon, aerial behaviours and human effects on dolphin behaviour.

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PUBLICATIONS



Shawky, A. M. (2024). Dugong feeding ecology along the Egyptian Red Sea. In: Coral reefs and associated marine fauna around the Arabian Peninsula. Eds: N.M.A. Rasul and I.C.F. Stewart. Taylor and Francis.


Shawky, A. M. and A. De Maddalena (2024). Photo-identification of the oceanic whitetip shark (Carcharhinus longimanus) at Elphinstone Reef, Egypt, Red Sea. In: Coral reefs and associated marine fauna around the Arabian Peninsula. Eds: N.M.A. Rasul and I.C.F. Stewart. Taylor and Francis.


Shawky, A. M. and Shabaka S. H. (2024). The grazing effects of dugongs on Seagrass meadows; a field experiment at Wadi El Gemal National Park, Red Sea, Egypt. In: Oceanographic and marine environmental studies around the Arabian Peninsula. Eds: N.M.A. Rasul and I.C.F. Stewart. Taylor and Francis.


Shawky A. M, Sallam W. S. and Mohamed S. Z. (2024). Assessing dugong distribution and overlapping threats along the northwestern Red Sea, Egypt. Egyptian Journal of Aquatic Biology & Fisheries. ISSN 1110 – 6131. Vol. 28(1): 1455 – 1488.


Shawky, A. M., Christiansen F. and Ormond R. (2020). Effects of Swim-wit h-Dolphin Tourism on the Behavior of Spinner Dolphins, at Samadai Reef, Egyptian Red Sea. Aquatic Conserv: Mar Freshw Ecosyst. 2020; 1–12. https://doi.org/10.1002/aqc.333.


Shawky, A. M. (2019a). Evidence of the occurrence of a large dugong in the Red Sea, Egypt. Egyptian Journal of Aquatic Research, 45: 247–250. https://doi.org/10.1016/j.ejar.2019.08.00.


Shawky, A. M., (2019b). Analysis of Feeding Trails Provides Evidence of the Number of Dugongs Excavating Seagrass at Key Habitats Seasonally in the Egyptian Red Sea. The Rufford Foundation.


Shawky A. M., Sallam W. S., Alwany M. A., Mohamed D. A. and Mohamed S. Z. (2019). Photo identification of Dugongs in Marsa Alam and Wadi El Gemal National Park, Indian Journal of Geo-Marine Sciences, 48 (9): 1351-135.


Nasr D., Shawky A. M., and Vine P. (2019). Status of Red Sea Dugongs. In: Rasul N., Stewart I. (eds) Oceanographic and Biological Aspects of the Red Sea. Springer Oceanography. Springer, Cha.


Shawky A. M., Sallam W.S., Alwany M. A., Mohamed D. A. and Mohamed S. Z. (2017). Photo identification of Dugongs in Marsa Alam and Wadi El Gemal National Park, western Egyptian coast of the Red  Sea. Al Azhar Bulletin of Science, Vol. (28) No. 2, D, 1-10.


Shawky A. M., Sallam W. S., Alwany M. A., Mohamed D. A. and Mohamed Z. (2016). Stranding of a neonatal dugong calf in Wadi El  Gemal National  Park: Implications for dugong conservation in Egypt. Al Azhar Bulletin of Science Vol. (27) No.2, Dec., 1-11.


Shawky A. M., Alwany M. A., Zakarea S. and El-Etreby S. (2015). Estimation of the abundance of the spinner dolphin Stenella longirostris using photo identification technique in Samadai Reef, Red Sea, Egypt. CATRINA, 10 (1): 61-73.


Shawky, M. and De Maddalena A. (2013). Human impact on the presence of sharks at diving sites of the Southern Red Sea, Egypt. Bollettino del Museo di Storia Naturale di Venezia, 64: 51-62.


Shawky A. M. and Afify (2008). Behaviour of Spinner Dolphin at Sha'ab Sa madai, Marsa Alam, Red Sea, Egypt. Egyptian Journal of Bio logy, 2008, Vol. 10, pp 36-41.