Supplementary Figure 4. Photographs showing the developed stage of the eggs carried by the berried female flathead lobsters (Thenus orientalis) that were collected in November and December 2016 from waters of Saudi Arabia in the Arabian Gulf.
For millennia, coastal and marine ecosystems have adapted and flourished in the Red Sea’s unique environment. Surrounded by deserts on all sides, the Red Sea is subjected to high dust inputs and receives very little freshwater input, and so harbors a high salinity. Coral reefs, seagrass meadows, and mangroves flourish in this environment and provide socio-economic and environmental benefits to the bordering coastlines and countries. Interestingly, while coral reef ecosystems are currently experiencing rapid decline on a global scale, those in the Red Sea appear to be in relatively better shape. That said, they are certainly not immune to the stressors that cause degradation, such as increasing ocean temperature, acidification and pollution. In many regions, ecosystems are already severely deteriorating and are further threatened by increasing population pressure and large coastal development projects. Degradation of these marine habitats will lead to environmental costs, as well as significant economic losses. Therefore, it will result in a missed opportunity for the bordering countries to develop a sustainable blue economy and integrate innovative nature-based solutions. Recognizing that securing the Red Sea ecosystems’ future must occur in synergy with continued social and economic growth, we developed an action plan for the conservation, restoration, and growth of marine environments of the Red Sea. We then investigated the level of resources for financial and economic investment that may incentivize these activities. This study presents a set of commercially viable financial investment strategies, ecological innovations, and sustainable development opportunities, which can, if implemented strategically, help ensure long-term economic benefits while promoting environmental conservation. We make a case for investing in blue natural capital and propose a strategic development model that relies on maintaining the health of natural ecosystems to safeguard the Red Sea’s sustainable development.
[During a study on the ecology and biology of the fan mussel, Pinna nobilis along the northern and eastern coasts of Tunisia, the presence of the shrimp, Pontonia pinnophylax and the crab, Nepinnotheres pinnotheres (Decapoda) associated with this bivalve, was recorded. The shrimp was collected only in the lagoon of Bizerte, whereas the crab was found exclusively at Stah Jaber (close to the fishing port of Monastir). P. nobilis was occupied by Pontonia pinnophylax in 23.3% of the samples and the associated shrimp population was dominated by males (63.6%). Shrimp couples were generally encountered inside the large pinnids, and the size of the shrimps increased with that of the host. P. nobilis was occupied by Nepinnotheres pinnotheres in 56.7% of the cases. The highest numbers of crabs were recorded in the oldest pinnids. The sex-ratio of the associated crab population was male-biased, 62.5% of the population being males. A morphological study of the two associated species revealed some features worth noting. In the female shrimp, distinguished by the right chela in the second pair of pereiopods being definitely larger than the left, the length of this appendage (both right and left) increased with individual size, but these two variables were found independent in the male shrimp. Concerning Nepinnotheres pinnotheres, the length of the two chelae of the first pair of pereiopods increased with that of the animal's body in both sexes. Dans le cadre d'une etude sur l'ecologie et la biologie de la grande nacre, Pinna nobilis, le long des cotes septentrionale et orientale de la Tunisie, nous avons observe la presence de la crevette Pontonia pinnophylax et du crabe Nepinnotheres pinnotheres (Decapoda) associes a ce bivalve. La crevette a ete recoltee uniquement dans la lagune de Bizerte, tandis que le crabe a ete trouve exclusivement a Stah Jaber (pres du port de peche de Monastir). P. nobilis etait occupee par Pontonia pinnophylax dans 23,3% des echantillons et la population etait dominee par les mâles (63,6%). Des couples de crevettes se rencontraient generalement dans les grandes nacres et la taille des crevettes augmentait avec celle de l'hote. P. nobilis etait occupee par Nepinnotheres pinnotheres dans 56,7% des cas. Les nombres les plus eleves de crabes ont ete releves dans les nacres les plus âgees. La sex-ratio de la population de crabe associee etait en faveur des mâles avec 62,5% de la population constituee de mâles. Une etude morphologique des deux especes associees a revele quelques faits qui valent la peine d'etre notes. Chez la crevette femelle, que l'on distingue par la pince droite de la deuxieme paire de pereiopodes nettement plus grande que la gauche, la longueur de cet appendice (a droite comme a gauche), augmente avec la taille de l'individu, mais ces deux variables sont independantes chez la crevette mâle. Chez Nepinnotheres pinnotheres, la longueur des deux pinces de la premiere paire de pereiopodes augmente avec celle du corps de l'animal dans les deux sexes., During a study on the ecology and biology of the fan mussel, Pinna nobilis along the northern and eastern coasts of Tunisia, the presence of the shrimp, Pontonia pinnophylax and the crab, Nepinnotheres pinnotheres (Decapoda) associated with this bivalve, was recorded. The shrimp was collected only in the lagoon of Bizerte, whereas the crab was found exclusively at Stah Jaber (close to the fishing port of Monastir). P. nobilis was occupied by Pontonia pinnophylax in 23.3% of the samples and the associated shrimp population was dominated by males (63.6%). Shrimp couples were generally encountered inside the large pinnids, and the size of the shrimps increased with that of the host. P. nobilis was occupied by Nepinnotheres pinnotheres in 56.7% of the cases. The highest numbers of crabs were recorded in the oldest pinnids. The sex-ratio of the associated crab population was male-biased, 62.5% of the population being males. A morphological study of the two associated species revealed some features worth noting. In the female shrimp, distinguished by the right chela in the second pair of pereiopods being definitely larger than the left, the length of this appendage (both right and left) increased with individual size, but these two variables were found independent in the male shrimp. Concerning Nepinnotheres pinnotheres, the length of the two chelae of the first pair of pereiopods increased with that of the animal's body in both sexes. Dans le cadre d'une etude sur l'ecologie et la biologie de la grande nacre, Pinna nobilis, le long des cotes septentrionale et orientale de la Tunisie, nous avons observe la presence de la crevette Pontonia pinnophylax et du crabe Nepinnotheres pinnotheres (Decapoda) associes a ce bivalve. La crevette a ete recoltee uniquement dans la lagune de Bizerte, tandis que le crabe a ete trouve exclusivement a Stah Jaber (pres du port de peche de Monastir). P. nobilis etait occupee par Pontonia pinnophylax dans 23,3% des echantillons et la population etait dominee par les mâles (63,6%). Des couples de crevettes se rencontraient generalement dans les grandes nacres et la taille des crevettes augmentait avec celle de l'hote. P. nobilis etait occupee par Nepinnotheres pinnotheres dans 56,7% des cas. Les nombres les plus eleves de crabes ont ete releves dans les nacres les plus âgees. La sex-ratio de la population de crabe associee etait en faveur des mâles avec 62,5% de la population constituee de mâles. Une etude morphologique des deux especes associees a revele quelques faits qui valent la peine d'etre notes. Chez la crevette femelle, que l'on distingue par la pince droite de la deuxieme paire de pereiopodes nettement plus grande que la gauche, la longueur de cet appendice (a droite comme a gauche), augmente avec la taille de l'individu, mais ces deux variables sont independantes chez la crevette mâle. Chez Nepinnotheres pinnotheres, la longueur des deux pinces de la premiere paire de pereiopodes augmente avec celle du corps de l'animal dans les deux sexes.]
Despite the important role of marine mammals in marine ecosystems and the imperative for their conservation, there is still a great lack of information on the diversity, distribution, and density of these animals in the Saudi waters of the Arabian Gulf. To fill this gap, an integrative data-collection approach including fishermen’s questionnaires, opportunistic sighting reports, and directed boat-based surveys, was undertaken between 2016 and 2020, leading to the first scientific report of marine mammal diversity, distribution, and density in the region. The results of the different approaches carried out during the study confirmed a high diversity of cetaceans on the west coast of the study area, with bottlenose dolphins ( Tursiops aduncus ), humpback dolphins ( Sousa plumbea ) and dugongs ( Dugong dugon ) as the most common species. While the two dolphin species were found to be widely distributed in both coastal and offshore waters, D. dugon appears to occur exclusively in coastal waters in the southern part of the study area, mainly in the Gulf of Salwah. The presence of both species of dolphins increased during the summer months and in the vicinity of the numerous oil and gas facilities in this region. The distribution of the observed dolphins was found mostly within a 10–20 km radius around each facility. Other cetacean species observed less frequently in the area include Bryde’s whale ( Balaenoptera edeni ), killer whale ( Orcinus orca ), common dolphin ( Delphinus delphis ) and finless porpoise ( Neophocaena phocaenoides ). Regarding the density of marine mammals in the region, boat-based surveys confirmed the results of fishermen’s questionnaires and reports of opportunistic sightings, with bottlenose and humpback dolphins being the most abundant species. These results provide a baseline for policies oriented to the conservation of mammals in the Saudi waters of the Arabian Gulf.
