Sharks/Rays

Methods

Our intention is to develop a dedicated approach for sharks in 2023. Most of our sightings until now have been opportunistic observations made during visits for other purposes to TRS and Amaala locations. For example, rays, sharks and guitarfish occurring in shallow waters around islands were recorded by survey team members conducting turtle nesting surveys. In addition, sharks and rays were observed during reef surveys and by a team conducting large-area surveys to identify suitable places for moorings to be located. Therefore, our results to date are not part of a systematic survey but are nevertheless sufficient to give us an understanding of the species present in our areas, along with some indication of their relative abundance.

Results

In the Amaala area, there were five species of shark observed and eight species of ray. The most common shark species was the Whitetip reef shark, which was commonly sighted during fish/benthic monitoring and manta-tow surveys. In the waters around both An Numan Island and Nabaqiyah Island, multiple juvenile Blacktip reef sharks (including a group of eight individuals) were observed – suggesting that those are nursery areas. The most frequently observed ray at both Amaala and TRS was the Bluespotted ray, which is common throughout the Red Sea. Oceanic manta have been reliably reported from the waters around An Numan too, though not yet by our team.

Within TRS, there have been observations of eight species of shark and 10 species of ray. The most frequently observed sharks were juvenile Blacktip reef sharks in the shallows around some islands. A single Whale shark (endangered) was observed feeding in waters near Sheybarah in late 2022. Using an international online database that compares the unique “fingerprint” made by the spots and stripes on the side of the shark, we learned that the same individual was previously observed in the northern Gulf of Aqaba on 22 Aug., 2020. We also received a reliable report of a Whale shark near An Numan Island, but without a photograph suitable for identifying the individual.

Juveniles of multiple elasmobranch species, including an Eagle ray, Blacktip reef sharks, Fantail rays, and Whitetail stingrays, were observed at islands within TRS, as was the case at the Amaala islands and at TRS the previous year. Since 2021, two additional species of ray (Porcupine ray and Blotched ray) and a Bottlenose wedgefish (critically endangered) were also observed at TRS. As in 2021, Halavi guitarfish were frequently observed in TRS waters. Halavi are a regional endemic that is critically endangered. As most sightings have been of juveniles, we have a strong indication that there are nursery habitats for this species in our area and are working with partners to learn more. We also observed a single Halavi guitarfish at Amaala this year.

Table: Species observed at TRS & Amaala. Numbers indicate the number of observations of each species during 2022 surveys. Checks indicate reliable previous reports of observations of these species within the project areas. Note that an observation may be of an individual or of a group. Hence, total number of individuals seen can be much higher than the number of observations

Halavi Guitarfish Tagging Study

During 2022, we observed 339 Halavi guitarfish around 26 islands and along the coast at TRS, including individuals measuring from 20-30cm to over 1m in length. Having observed similar numbers and distributions in 2021, it’s clear that the Al Wajh lagoon is a regionally significant site, with several nursery areas for this critically endangered species. Together with researchers from KAUST, we’re studying this species’ habitat use and movement. Our study area is a section of nearshore habitat at Quman Island, where juveniles have been regularly seen. We assess their movement using acoustic tagging. This involves implanting small tags into guitarfish body cavities. These tags “ping” with a unique sequence. When a tagged guitarfish is near one of the receivers deployed around the area, the pings provide time-stamped evidence of their presence and builds information on individuals’ movements.

Over two weeks in November of 2022, the team from KAUST partnering with our team captured 57 guitarfish (24 female, 33 male) and acoustically tagged 16 of those. Thirty-three of the guitarfish captured were under 40cm in length, which is too small to tag. However, this abundance of small guitarfish further supports the hypothesis that this may be a nursery area for the species (estimated size at birth 25-29cm). Our team will return every four months to download data from the acoustic receivers. Given the conservation importance of this species to us, we’re planning to expand our work next year to include regional assessments of genetic connectivity and population size that will give us a much clearer idea of the significance of the Al Wajh population.

Marine Mammals Methods

Throughout 2022, members of our monitoring team and some of the most experienced boat captains we work with recorded cetacean and dugong sightings – often while these mammals transited through the TRS area. The recorded data includes species type (for cetacean observations), location, date, and time. Where possible, we took an identifying photograph. Because some dolphin species are difficult to differentiate from above the water or at a distance, some dolphin observations were not made to species level. As this is particularly true for Bottlenose dolphins, we grouped the two local species (Common bottlenose and Indo-Pacific bottlenose) for reporting purposes.

Results Cetaceans

Six species of cetacean have been reported in the Amaala project area, including three by our team in 2022. One of those, the Indian Ocean Humpback dolphin, is considered endangered by the IUCN Red List. One exciting observation from previous work around Amaala area is of a group of Orca (killer whales). This species is a rare visitor anywhere in the Red Sea, with fewer than 10 previous reports within the basin (Notarbartolo Di Sciara et al., 2017). The observation at Amaala is by some distance the most northerly sighting we are aware of for this species in the region.

Seven species of cetacean have been observed in TRS waters. During 2022 there were 29 observations of individual cetaceans or pods. This included a large pod of Risso’s dolphin seen near Mardunah Island. Mixed pods of Indo-Pacific bottlenose and Indian Ocean Humpback dolphins were observed on multiple occasions; in fact mixed-species pods of this kind are common phenomena in the Red Sea (Gladstone & Fisher, 2000; Notarbartolo Di Sciara et al., 2017).

Spinner

Table: Cetacean species observed at TRS & Amaala (# observations indicates number of encounters with individuals or groups. Ticks indicate species that are known to be present, based on our previous data or other reliable observations)

Dugong

Although we did not conduct dugong surveys at Amaala in 2022, the team observed a dugong near An Numan Island. The majority of previous reliable dugong sightings at Amaala have been from that general area, with a particular small bay there appearing to be a high-use area. Planned surveys for 2023 will improve our data from that and other important dugong areas at both TRS and Amaala.

We have much more data from TRS. Since 2020, there have been 27 reliable observations of dugongs in TRS waters. These come from both members of the monitoring team, other survey efforts, and trusted local captains. Most of these sightings were of single individuals, however, there have been two confirmed sightings of adult-calf pairs and four other observations of pairs. Combining our sightings with historical data from earlier surveys (as shown to the right) and with results from the seagrass assessment described later in this report, we have the basis for dedicated future efforts to survey and manage this species in their key areas.