Southern Egyptian Red Sea Bays, Offshore Reefs and Islands IMMA

Criterion A – Species or Population Vulnerability

The area hosts Endangered Indian Ocean humpback dolphins and Vulnerable Dugongs. Dugong dugon, believed to be once widely distributed along the entire Red Sea coastal area wherever appropriate habitat for seagrass meadows existed, persist today scattered in fragmented locations, including the many marsas along the coast of the northern portion of the IMMA (Hanafy et al., 2006; Nasr et al., 2019; Shawky et al., 2017), all the way to the border with Sudan (and beyond), and perhaps also in the reef lagoons inaccessible to navigation comprised between Foul Bay and Hala’ib. The species is listed as Vulnerable by the IUCN, although the Red Sea and Gulf of Aden population is considered Data Deficient (Marsh & Sobtzick, 2015). Sousa plumbea are present, although infrequently encountered, in the shallowest portions of the area (both to the north and to the south of Ras Banas). In the area its abundance is unknown but it is thought to occur in low numbers in shallow habitats along the coast with the exclusion of the Gulf of Aqaba. Few sightings are reported along the coast surrounding Fury Shoal, and in the vicinity of Shalatin (Costa, 2015; Notarbartolo di Sciara et al., 2017).

Criterion B: Distribution and Abundance

Sub-criterion B1: Small and Resident Populations 

Tursiops aduncus is regularly observed throughout the IMMA, most often in proximity of coral reefs or in sheltered lagoons, and more occasionally in the coastal bays of the IMMA (Costa, 2015; Notarbartolo di Sciara et al., 2017). Population abundance estimates of Indo-Pacific bottlenose dolphins in the area north of Ras Banas indicate a population of 103 individuals (CV=0.34; Costa, 2015), often encountered in mixed-species groups with spinner dolphins. Recaptures of the same individuals over the relatively few sampling occasions available suggest the importance of the area for the group (Costa, 2015). A similar situation was observed south of Ras Banas, where the abundance estimate for the species was 108 individuals (CV=0.47, n=20; Costa, 2015). Four out of 46 distinctive individuals were recaptured in different years (three in 2010 and 2012, one in 2010 and 2011) at sites relatively close to each other (mean distance=38 km, SD=22.6), suggesting some level of long-term site fidelity to this region. None of the distinctive individuals encountered south of Ras Banas was ever recaptured north of it (Costa, 2015). Risso’s dolphins were concentrated in the area from Abu Fandira to the IMMA’s southern boundary. Groups ranged from 1 to 17 individuals and occasionally included calves. Of 74 distinctive, identified individuals, 11 were recaptured over the course of a 2010-2012 study (Costa, 2015). The pattern and location of recaptures led to suggest that the whole area, from St. John’s reefs to Qubbat’Isa (Abu Tess in the reference cited), might be used by the species (Costa, 2015). Photo-identification data for 2006 and 2011-2014 show that the Samadai and Satayah spinner dolphin reef-associated populations include long-term resident individuals of both sexes (Cesario, 2017; Fumagalli, 2016; Fumagalli et al., in press). At Samadai Reef, females exhibit stronger site fidelity than males, especially in the warm season (mid-April to mid-October) (Cesario, 2017). Capture-recapture routines returned stable, reef-associated Samadai and Satayah populations of ~200 non-calf individuals (Cesario, 2017; Fumagalli et al., in press), whereas species abundance in the area was estimated to be 6,961 individuals (CV=0.26; Costa, 2015). The area is also host to a small, fragmented resident population of dugongs (Hanafy et al., 2006; Nasr et al., 2019; Shawky et al., 2017). The photo-identification capture histories of 30 distinctive individuals in the northernmost portion of the IMMA suggested high fidelity to a specific site or to adjacent sites (Nasr et al., 2019, Shawky et al., 2017).

Sub-criterion B2: Aggregations

A relatively large group of common bottlenose dolphins inhabits Fury Shoal and surrounding waters. The only estimate available based on mark recapture data suggest that about 400 (CV=0.31) individuals use an area that extends about 200 km north and 200 km south of Fury Shoal. It is important to notice however, that the majority of the bottlenose dolphin sightings and individual recaptures occurred in Fury Shoal waters, thus suggesting that the area might be the core of the population, with some individuals dispersing further away. This is also confirmed by habitat modelling analyses showing that the maximum values of predicted abundances of groups for the species have their centre in the Fury Shoal area (Costa 2015).

Criterion C: Key Life Cycle Activities

Sub-criterion C1: Reproductive Areas

Mating, pregnancy, occurrence of newborn and older calves, as well as nursing and nurturing behaviours were regularly observed in the spinner dolphins schools encountered at the resting areas of Samadai and Satayah Reef. Mating is a behaviour commonly observed in the resting school (Cesario, 2017; Fumagalli et al., 2019), as already reported elsewhere (Norris et al., 1994; Silva-Jr. et al., 2005). The mating system of the spinner dolphins of Samadai Reef is polygynous (Cesario, 2017). Mother and calf pairs, including calves aged 1-3 years and juveniles, are common sights within resting schools all-year round (Cesario, 2017; Ismail, 2017; Notarbartolo di Sciara et al., 2009). The birth season corresponds to the summer months of June-August, when newborn calves are recorded (Cesario, 2017; Fumagalli et al., in press; Ismail, 2017; Notarbartolo di Sciara et al., 2009). Visual, underwater observations documented the regular presence of pregnant females within the resting schools (Cesario, 2017; Fumagalli et al., In press; Ismail, 2017). Births have never been observed inside the reef lagoon, but photo-identified, distinctive pregnant females have been encountered in the few days immediately preceding and succeeding the estimated delivery date (Cesario, 2017; Ismail, 2017), thus suggesting that the area is safe and suitable during vulnerable phases of late pregnancy and care of very young newborn calves. The features of the resting area appear therefore to be ideal not only for resting, but also for nursing and nurturing of newborn as well as older calves. At Qubbat’Isa Reef, calves were recorded in all sightings (Fumagalli, 2016). During three encounters in the lagoon of Abu Fandira Reef in July 2012, groups ranged in size from 24 to 55 individuals. These schools always included calves, in two cases newborn calves. This may indicate that the June-August birth season identified in Samadai and Satayah reefs also applies here. As hypothesised for the northern, better known spinner dolphin resting areas, these southern, less-known sites appear to possess ideal features not only for resting, but also for nursing and nurturing. Following the observation of small feeding trails, as well as the sightings of several calves, several of the coastal bays and areas in the northern portion of the IMMA (i.e. Ras Bagdady, Marsa Egla and Marsa Assalaya) were suggested to be nursery ground for the dugong (Shawky et al., 2017, 2016).