A multi-method characterization of Elasmobranch & Cheloniidae communities of the north-eastern Red Sea and Gulf of Aqaba

The Red Sea is particularly biodiverse, hosting high levels of endemism and numerous populations whose extinction risk is heightened by their relative isolation. Elasmobranchs and sea turtles have likely suffered recent declines in this region, although data on their distribution and biology are severely lacking, especially on the eastern side of the basin in Saudi Arabian waters. Here, we present sightings of elasmobranchs and sea turtles across the north-eastern Red Sea and Gulf of Aqaba collected through a combination of survey methods. Over 455 survey hours, we recorded 407 sightings belonging to 26 elasmobranch species and two sea turtle species, more than 75% of which are of conservation concern. We identified 4 species of rays and 9 species of sharks not previously recorded in Saudi Arabia and report a range extension for the pink whipray (Himantura fai) and the round ribbontail ray (Taeniurops meyeni) into the Gulf of Aqaba. High density of sightings of conservation significance, including green and hawksbill sea turtles and halavi guitarfish were recorded in bay systems along the eastern Gulf of Aqaba and the Saudi Arabian coastline bordering the north-eastern Red Sea, and many carcharhinid species were encountered at offshore seamounts in the region. Our findings provide new insights into the distribution patterns of megafaunal assemblages over smaller spatial scales in the region, and facilitate future research and conservation efforts, amidst ongoing, large-scale coastal developments in the north-eastern Red Sea and Gulf of Aqaba

The Status of Coastal Benthic Ecosystems in the Mediterranean Sea: Evidence From Ecological Indicators

The Mediterranean Sea is subject to multiple human pressures increasingly threatening its unique biodiversity. Spatially explicit information on the ecological status of marine ecosystems is therefore key to an effective maritime spatial planning and management, and to help the achievement of environmental targets. Here, we summarized scientific data on the ecological status of a selection of marine ecosystems based on a set of ecological indicators in more than 700 sites of the Mediterranean Sea. For Posidonia oceanica seagrass beds, rocky intertidal fringe, and coastal soft bottoms, more than 70% of investigated sites exhibited good to high ecological conditions. In contrast, about two-thirds of sites for subtidal rocky reefs were classified to be in moderate to bad conditions, stressing the need for prioritizing conservation initiatives on these productive and diverse environments. Very little quantitative information was available for the southern Mediterranean Sea, thus monitoring programs and assessments in this area are essential for a representative assessment of the health of marine coastal ecosystems in the whole basin. This overview represents a first step to implement a baseline that, through georeferenced data on ecological status, could help identifying information gaps, directing future research priorities, and supporting improvements to spatial models of expected cumulative impacts on marine ecosystems

The Status of Coastal Benthic Ecosystems in the Mediterranean Sea: Evidence From Ecological Indicators

The Mediterranean Sea is subject to multiple human pressures increasingly threatening its unique biodiversity. Spatially explicit information on the ecological status of marine ecosystems is therefore key to an effective maritime spatial planning and management, and to help the achievement of environmental targets. Here, we summarized scientific data on the ecological status of a selection of marine ecosystems based on a set of ecological indicators in more than 700 sites of the Mediterranean Sea. For Posidonia oceanica seagrass beds, rocky intertidal fringe, and coastal soft bottoms, more than 70% of investigated sites exhibited good to high ecological conditions. In contrast, about two-thirds of sites for subtidal rocky reefs were classified to be in moderate to bad conditions, stressing the need for prioritizing conservation initiatives on these productive and diverse environments. Very little quantitative information was available for the southern Mediterranean Sea, thus monitoring programs and assessments in this area are essential for a representative assessment of the health of marine coastal ecosystems in the whole basin. This overview represents a first step to implement a baseline that, through georeferenced data on ecological status, could help identifying information gaps, directing future research priorities, and supporting improvements to spatial models of expected cumulative impacts on marine ecosystems

Predator-prey interactions in coral reef fish : the implications of predation risk on the behavior and growth of prey

Sublethal or nonlethal predator-prey interactions (predation risk) can influence prey species' behaviours and food web dynamics across a wide-range of ecological communities and diverse taxa. In this thesis, I explore the potential for predation risk to influence the behaviour and growth of marine animals. Local predation risk fluctuates greatly in space and time and anti-predator behaviour is expected to be selected over evolutionary times to optimise prey fitness. Flexibility in behavioural responses to predation risk is likely to be an evolutionary adaptation that mitigates the trade-offs between the costs of physical and chemical defences against predators and maximising growth and reproduction. In high-risk situations during the life of an animal, antipredator behaviour maximising survival may reduce net energy intake by an individual and potentially its reproductive fitness relative to net energy intake and fitness in low risk situations. I identify major determinants of, and common prey responses to, predation risk in marine environments. I argue that nonlethal predator-prey interactions influence the behaviour of marine species and, because of the high phenotypic plasticity characteristic of these animals, are likely to affect life-history traits such as growth and size-at-maturity. These effects may be especially significant in speciose communities, such as coral reefs, where the number of nonlethal interactions is high. I examine the anti-predator behaviour of juveniles and adults of a number of species of site-attached coral reef fishes. In order to test for a change in behaviour due to predation risk, I exposed these fishes to a caged Serranid predator, Cephalopholis cyanostigma, in laboratory aquaria. Seeking and associating with refuge was the most common antipredator response in diurnal species of the prey fish, P. moluccensis and P. amboinensis. Conversely, two nocturnal prey species (Apogon fragilis and Cheilodipterus quinquelineatus) moved away from their refuge in the presence of the reef piscivore, presumably to avoid attacks from potential ambush predators. Both size classes of the four species of prey examined reduced their foraging significantly in the presence of a predator. Vigilance, however, was primarily a role assumed by adults and not juveniles. Such differing ontogenetic behaviour and the associated selected advantages may help explain the persistence of mixed size-class groups, a common feature in social groups of coral reef fish planktivores. Moreover, anti-predator behaviour of individual coral reef fish may depend on the ecology of that species and the specific foraging of its ontogenetic stage. I then examined, more closely, predator-induced modifications in foraging behaviour of a common tropical fish, Pomacentrus moluccensis, in groups of different size and at different ontogenetic stages on coral reefs in the Great Barrier Reef. Different group sizes of P. moluccensis were exposed to a potential predator or non-predator and changes in foraging behaviour of juveniles and adults were observed. In the presence of a predator, foraging effort, estimated by the number of bites taken and foraging distance away from shelter, was reduced whilst the presence of a non-predator caused an increase in foraging distance of P. moluccensis. In the presence of a predator, adults exhibited greater reduction in foraging than juveniles. Juveniles continued foraging even in the presence of predators which may help explain maintenance of high growth rates in young coral reef fishes. In contrast, reduced foraging in adults might reflect an emphasis on survival. Prey fish in large groups exposed to a predator displayed less reduction in foraging effort compared to fish in smaller groups. This was consistent with observational surveys that show a reduction in per capita vigilance with an increase in prey group size. Therefore, aggregating in coral reef fishes, a common phenomenon, may serve to dilute predation risk and increase individual foraging effort in social groups of pomacentrids. These results suggest that nonlethal predator-prey interactions may have an important effect on food ingestion rates and therefore energy uptake of coral reef fish. These effects were mediated by prey group size and ontogeny. Finally, I investigated the effects of non-fatal interactions on prey morphology and growth, and explored how intraspecifc density may influence these effects. Using experimental manipulations of group sizes of Pomacentrus moluccensis, and a system of artificial coral reefs and cages at Lizard Island on the Great Barrier Reef (GBR), I tested the prediction that predation risk would reduce foraging and growth in this species while grouping would dilute this risk and ameliorate some of these negative effects. Results indicated that the risk of predation affected the behaviour and reduced the growth rate of the prey and that these effects were most pronounced in small prey group sizes. Observational data collected from natural reefs in the immediate vicinity suggested that a reduction in per capita vigilance with increase in group size may explain the diminished individual costs of predation risk recorded in large groups. These results suggest that predators may significantly reduce the growth of a prey individual at low prey group size, but will have a smaller effect at higher prey group sizes due to a reduction in per capita vigilance. This suggests that social groups in coral reef fish systems may have evolved, in part, to optimise the trade-offs between survival and growth. Suppression of growth due to predation risk may affect population dynamics of adult coral reef fish by regulating the rate of individuals reaching reproductive maturity and/or by increasing the probability of size-selective mortality on juveniles

Evaluating stakeholder participatory processes in policy development for Marine Protected Areas

This paper evaluates two stakeholder participatory workshops (local communities and tourism stakeholder) to support the development of a management plan for South Ari Atoll Marine Protected Area (SAMPA), Maldives. SAMPA is the largest MPA in the country declared by Maldives to preserve one of the largest whale shark aggregations in the world. However, to date it exists with no management plan to date. The objective of the workshops was to consult with stakeholders on a range of potential regulatory and governance mechanisms proposed for the MPA that can be included in a potential management plan. The paper finds that the two stakeholder workshops had, both functional and dysfunctional aspects that influenced the potential design of a management plan for SAMPA. Overall, the workshops represented a clear opportunity for collective learning and collaboration that fostered dialogue and deliberation. However, important and influential stakeholders were under-represented at the workshops. Furthermore, a reluctance of government to demonstrate how the outcomes of the workshop would be integrated in its decision-making left many participants feeling sceptical about the fairness, equity and effectiveness of the processes that would follow. With no management plan to date, this paper proposes that any future stakeholder process in SAMPA should be underpinned by well informed governance and regulatory options that have the support and commitment of the government which can ensure SAMPA's ecosystem services are sustained to benefit long-term human well-being

Marine World Heritage: creating a globally more balanced and representative list

The World Heritage Convention provides the potential for a comprehensive policy framework that allows for identification, management, governance, and protection of the world's most outstanding natural marine areas.Benefits of World Heritage (WH) listing include increased international attention and technical cooperation, governmental support and improvements to management, and enhanced funding opportunities.There are currently only 46 (of 981 or 4.7%) World Heritage Sites (WHS) that have been inscribed for their outstanding marine values, and these marine WHS (mWHS) represent predominantly tropical as opposed to temperate and polar ecosystems.Forty-seven (76%) of the world's 62 nearshore biogeographic provinces do not contain any mWHS or contain a low (<1%) coverage that is unlikely to capture the full range of values and features present in these provinces. A large proportion of the world's offshore provinces, representing 40% of the global ocean, do not contain any mWHS.To fulfill the World Heritage Committee's Global Strategy for a Representative, Balanced and Credible World Heritage List, States are encouraged to increase efforts to identify and nominate marine sites of potential Outstanding Universal Value (OUV), especially in biogeographic regions that are not yet represented, or underrepresented, on the WH List.However, as the criteria and guidance for the Convention are based primarily on terrestrial systems, further guidance on using them in the marine context is provided here. It is proposed that physical oceanographic features be considered under criterion (viii) 'geology and oceanography', while biological oceanographic features be considered under criterion (ix) 'ecological and biological processes'. Use of criteria (vii) 'superlative phenomena' and (x) 'species' can follow current guidance for terrestrial systems.Potential approaches that can help address gaps in biogeographic representation of marine WHS and create a more balanced and representative marine World Heritage List are outlined here

King tuna: Indian Ocean trade, offshore fishing, and coral reef resilience in the Maldives archipelago

The traditional offshore pole-and-line tuna fishery of the Maldives has historically promoted low levels of reef fishing in this archipelago. While the tuna fishery is old and extensive-some evidence suggests it has been in place for over a thousand years-the reasons for its development have not been closely examined. Why did an offshore fishery develop in such small and isolated islands with abundant and easily accessible nearshore reefs? Why is tuna considered the "king of fish" in the Maldives, in contrast to many other islands across the globe where reef fish are prized for a wide variety of cultural and social reasons, often deeply rooted in community histories? In this article, we use a historical approach to uncover some of the drivers of this fishery, and the long-term consequences it has had for the resilience of this island chain. We trace the written accounts of travellers, voyagers, and traders, in addition to more recent research to gain an understanding of how early Indian Ocean trade networks may have shaped the development of this fishery over time. We propose that the early growth of the tuna fishery was likely tied to the trade in money cowries (Monetaria moneta), of which the Maldives was a major global supplier. A regional demand and market for dried tuna from the fourteenth century onwards contributed to the income of Maldivians and promoted and supported reef health by encouraging relatively low levels of reef fishing. However, the emergence and substantial growth of the Maldivian tourist industry in the past few decades are resulting in a shift in local consumption preferences and increased exploitation of reef fisheries. Exploring this history is important, not only to help contextualize the modern governance of the offshore tuna fishery, but also for a more nuanced understanding of the social, cultural, and ecological dynamics that have shaped Maldivian coral reefs in the past with implications for those that will do so in the future

Do marine protected areas in the Red Sea afford protection to dugongs and sea turtles?

Dugongs (Dugong dugon) and most sea turtles are threatened by gill nets and other human activities worldwide. In the Red Sea these animals are potentially isolated from populations in other areas of the world. This isolation would make recovery following major population decline in the Red Sea unlikely. Protected areas are promoted as a management tool to safeguard these animals from human activities. Elba National Park, Egypt, supports populations of dugongs and sea turtles, as well as a growing fishing industry. We undertook a survey of fishers to determine if dugongs and sea turtles formed bycatch in Elba National Park. Specifically, we quantified the proportion of fishers operating in Elba National Park who had caught these animals as bycatch in fishing nets and the proportion of fishers who perceived that sea turtle eggs were still collected. This study indicates that at least one protected area in the Red Sea is not achieving conservation objectives relating to these animals. Nine and eighty percent of fishers reported having caught dugongs and sea turtles in nets, respectively. Seven percent of fishers perceived that people still collected turtle eggs. Elba National Park is failing to protect these animals for reasons including: it is managed solely as an IUCN Category VI Protected Area; fishers lack awareness of laws pertaining to these animals; and fishers are highly resource dependent. Potential management strategies to reduce bycatch include the establishment of IUCN Category 1a Protected Areas in important dugong and sea turtle habitat, encouraging fishers to adopt fishing gear that poses less risk to megafauna and raising awareness among fishers of the protected status of dugongs and sea turtles

Can luxury and environmental sustainability co-exist? Assessing the environmental impact of resort tourism on coral reefs in the Maldives

Tourism is a mainstay of the Maldivian economy, with approximately 1 million tourists a year attracted by the rich tropical marine ecosystems and the luxurious service and experience offered in the country's resorts. However, developing and running resorts to cater for tourists on relatively small and remote islands presents various environmental challenges for surrounding coral reefs. We investigated the potential impacts of tourism operations, including construction, sewage, pollution and sand pumping, on reef condition around seven islands exclusively leased for resorts. We reported variable environmental sustainability of resort practices, with some in particular being damaging. The initial construction of the resort represented an acute impact on reef condition, inferred from the lower coral cover and lower abundance of large and mature coral colonies around the newest resorts investigated. Levels of algal cover and loose sediment were higher on reef sites near the resorts, where the majority of the damaging activities take place. However, resorts activities were less important for explaining reef condition than the differences between habitats, such as the reef flat or slope, and the atoll where the resort was located. Compared to other regions globally, tourist development appeared to have less impact on reef condition in the Maldives maintaining moderately high coral cover and features of a resilient ecosystem. It is important to note that better waste management and the use of environmentally friendly infrastructure development is needed to reduce the impacts of resorts in the Maldives