scholarly journals Tourism Impact on Marine Ecosystems in the North of Red Sea

2019 ◽  
Vol 13 (1) ◽  
pp. 10
Author(s):  
Abderrahim Lakhouit
Keyword(s):  
Coral Reefs ◽  
Red Sea ◽  
Human Activities ◽  
Marine Ecosystems ◽  
Tourism Impact ◽  
The North ◽  
Algae Blooms ◽  
Marine Habitats ◽  
The Impact ◽  
Northern Red Sea

The unique marine environment of the northern Red Sea region is among the richest and most productive marine ecosystems in the world. The sea is populated with extensive algae blooms and at least five types of coral reefs. However, the region’s tourism sector is largely dependent on the surrounding environment, including the coral reefs, which are highly sensitive to human activities. A large tourist project (Neom) is scheduled to be installed in the northern Red Sea, further increasing tourist activities in the area and leading to human intrusion into crucial but fragile marine habitats such as seagrass beds, coral reefs and mangrove stands. The present study investigates how human activities are currently affecting Red Sea ecosystems. Field visits were done in order to investigate and to study human activities impact on marine ecosystems in the north of Red Sea. To the best of our knowledge, this work is the first of its kind to evaluate the impact of tourism on marine ecosystems in Saudi Arabia’s northern Red Sea coast.

scholarly journals Abundance and Diversity of Holothuroids in Shallow Habitats of the Northern Red Sea

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Boaz Yuval ◽  
Lee Sudai ◽  
Yarden Ziv
Keyword(s):  
Coral Reefs ◽  
Protected Areas ◽  
Red Sea ◽  
Marine Protected Areas ◽  
Common Species ◽  
Sea Cucumbers ◽  
Marine Habitats ◽  
Human Use ◽  
Abundance And Diversity ◽  
Northern Red Sea

Holothuroid sea cucumbers are vital members of Coral Reefs and associated marine habitats and provide vital ecological services. In the southern regions of the Red Sea their populations have been decimated by overfishing. The main objective of this study was to test the hypothesis that the northern part of the Red Sea serves as an ecological refuge for the species threatened farther to the south. Accordingly, populations of sea cucumbers in 4 shallow sites south of Eilat, Israel (29°33′00N 34°57′14E), were repeatedly surveyed from November 2013 to April 2014. Overall 11 species were observed in these shallow sites. Their abundance and diversity differed significantly between sites, but not temporally. In sites in marine protected areas, with an intact fringing reef, diversity was high, withHolothuria edulisandBohadschiasp. being the most common species. In areas with higher human use and characterized by rubble and scattered corals, diversity was low, andActinopyga bannwarthiwas the most common species. The observed abundance and diversity did not support the refuge hypothesis. These findings are discussed in relation to other surveys of abundance and diversity in similar habitats.

Coral cover and partial mortality on anthropogenically impacted coral reefs at Eilat, northern Red Sea

2004 ◽  
Vol 48 (3-4) ◽  
pp. 248-253 ◽  
Author(s):  
Jeffrey Wielgus ◽  
Nanette E. Chadwick-Furman ◽  
Zvy Dubinsky
Keyword(s):  
Coral Reefs ◽  
Red Sea ◽  
Coral Cover ◽  
Partial Mortality ◽  
Northern Red Sea

scholarly journals Evidence on the impacts of chemicals arising from human activity on tropical reef-building corals; a systematic map

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Dakis-Yaoba Ouédraogo ◽  
Mathilde Delaunay ◽  
Romain Sordello ◽  
Laetitia Hédouin ◽  
Magalie Castelin ◽  
...  
Keyword(s):  
Climate Change ◽  
Coral Reefs ◽  
Nutrient Enrichment ◽  
Human Activities ◽  
Additional Stress ◽  
Chemical Pollution ◽  
Systematic Map ◽  
Search String ◽  
Tropical Reef ◽  
The Impact

Abstract Background Tropical coral reefs cover ca. 0.1% of the Earth’s surface but host an outstanding biodiversity and provide important ecosystem services to millions of people living nearby. They are currently threatened by local stressors (e.g. nutrient enrichment and chemical pollution arising from poor land management, sewage effluents, agriculture, industry) and global stressors (mainly seawater warming and acidification, i.e. climate change). Global and local stressors interact in different ways, but the presence of one stressor often reduces the tolerance to additional stress. While global stressors cannot be mitigated solely by local actions, local stressors can be reduced through ecosystem management, therefore minimizing the impact of climate change on coral reefs. We systematically mapped the evidence of impacts of chemicals arising from anthropogenic activities on tropical reef-building corals, which are the main engineer species of reef ecosystems, to inform decision-makers on the available evidence on this topic. Methods We searched the relevant literature using English terms combined in a tested search string in two publication databases (Scopus and Web Of Science Core Collection). The search string combined terms describing the population (tropical reef-building corals) and the exposure (chemicals). We searched for additional literature through three search engines, three dissertations repositories, 11 specialist websites, and through a call to local stakeholders. Titles, abstracts, and full-texts were successively screened using pre-defined eligibility criteria. A database of all studies included in the map with coded metadata was produced. The evidence was described and knowledge clusters and gaps were identified through the distribution and frequency of studies into types of exposure and/or types of outcomes and/or types of study. Review findings The initial searches identified 23,403 articles which resulted in 15,177 articles after duplicate removal. Among them, 908 articles were retained after screening process, corresponding to 7937 studies (a study being the combination of a taxon, an exposure, and an outcome). Among these studies, 30.5% dealt with the impact of nutrient enrichment on corals while 25% concerned the impact of human activities without reference to a chemical. The most measured outcomes were those related to the chemical concentration in corals (bioaccumulation, 25.8%), to coral physiology (16.9%), cover (14%), and mortality (9%). Half of the studies (48.4%) were experimental—the exposure was controlled by the researchers—and were conducted in laboratory conditions (39.4%) and in situ (9%). The most studied taxa, exposure, and outcomes were different between experimental and observational studies. Conclusions We identified four well-represented subtopics that may be amenable to relevant full syntheses via systematic reviews: (1) evidence on bioaccumulation of chemicals by corals; (2) evidence on the effects of nutrient enrichment on corals; (3) evidence on the effects of human activities on corals; and (4) evidence on the ecotoxicological effects of chemicals on corals (except nutrient enrichment). The systematic map shows that corals in their natural environment can be exposed to many categories of chemicals, and that there is a complete gap in experimental research on the combined effects of more than two categories of chemicals. We therefore encourage research on this topic.

scholarly journals Coral reef baselines: how much macroalgae is natural?

2013 ◽  
Author(s):  
John F Bruno ◽  
William F Precht ◽  
Peter S Vroom ◽  
Richard B. Aronson
Keyword(s):  
Coral Reef ◽  
Coral Reefs ◽  
Human Activities ◽  
Marine Ecosystems ◽  
The Other ◽  
Baseline Condition ◽  
Natural State ◽  
Resource Managers ◽  
Macroalgal Biomass ◽  
Effective Conservation

Identifying the baseline or natural state of an ecosystem is a critical step in effective conservation and restoration. Like most marine ecosystems, coral reefs are being degraded by human activities: corals and fish have declined in abundance and seaweeds, or macroalgae, have become more prevalent. The challenge for resource managers is to reverse these trends, but by how much? Based on surveys of Caribbean reefs in the 1970s, most reef scientists believe that the average cover of seaweed was very low in the natural state. On the other hand, evidence from remote Pacific reefs, ecological theory, and impacts of over-harvesting in other systems all suggest that, historically, macroalgal biomass may have been higher than assumed. Uncertainties about the natural state of coral reefs illustrate the difficulty of determining the baseline condition of even well-studied systems.

scholarly journals Why compare marine ecosystems?

2009 ◽  
Vol 67 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Steven A. Murawski ◽  
John H. Steele ◽  
Phillip Taylor ◽  
Michael J. Fogarty ◽  
Michael P. Sissenwine ◽  
...  
Keyword(s):  
Coral Reefs ◽  
Human Activities ◽  
Model Building ◽  
Marine Ecosystem ◽  
Marine Ecosystems ◽  
Learning By Doing ◽  
Ecosystem Dynamics ◽  
Comparative Approach ◽  
Ecosystem Responses ◽  
Continental Shelves

Abstract Murawski, S. A., Steele, J. H., Taylor, P., Fogarty, M. J., Sissenwine, M. P., Ford, M., and Suchman, C. 2010. Why compare marine ecosystems? – ICES Journal of Marine Science, 67: 1–9. Effective marine ecosystem-based management (EBM) requires understanding the key processes and relationships controlling the aspects of biodiversity, productivity, and resilience to perturbations. Unfortunately, the scales, complexity, and non-linear dynamics that characterize marine ecosystems often confound managing for these properties. Nevertheless, scientifically derived decision-support tools (DSTs) are needed to account for impacts resulting from a variety of simultaneous human activities. Three possible methodologies for revealing mechanisms necessary to develop DSTs for EBM are: (i) controlled experimentation, (ii) iterative programmes of observation and modelling (“learning by doing”), and (iii) comparative ecosystem analysis. We have seen that controlled experiments are limited in capturing the complexity necessary to develop models of marine ecosystem dynamics with sufficient realism at appropriate scales. Iterative programmes of observation, model building, and assessment are useful for specific ecosystem issues but rarely lead to generally transferable products. Comparative ecosystem analyses may be the most effective, building on the first two by inferring ecosystem processes based on comparisons and contrasts of ecosystem response to human-induced factors. We propose a hierarchical system of ecosystem comparisons to include within-ecosystem comparisons (utilizing temporal and spatial changes in relation to human activities), within-ecosystem-type comparisons (e.g. coral reefs, temperate continental shelves, upwelling areas), and cross-ecosystem-type comparisons (e.g. coral reefs vs. boreal, terrestrial vs. marine ecosystems). Such a hierarchical comparative approach should lead to better understanding of the processes controlling biodiversity, productivity, and the resilience of marine ecosystems. In turn, better understanding of these processes will lead to the development of increasingly general laws, hypotheses, functional forms, governing equations, and broad interpretations of ecosystem responses to human activities, ultimately improving DSTs in support of EBM.

Tectonics of the Northern Red Sea, insights from multibeam bathymetric mapping of Mabahiss Deep.

2020 ◽  
Author(s):  
Daniele Trippanera ◽  
Margherita Fittipaldi ◽  
Nico Augustin ◽  
Froukje M. van der Zwan ◽  
Sigurjón Jónsson
Keyword(s):  
Oceanic Crust ◽  
Red Sea ◽  
Spreading Rate ◽  
Ocean Floor ◽  
Tectonic Activity ◽  
Rift System ◽  
Central Volcano ◽  
The South ◽  
The North ◽  
Northern Red Sea

<p>The Red Sea is a unique place to study the birth of an oceanic rift basin and the interplay between magma and tectonics at a young divergent plate boundary. The Red Sea is a NNW-SSE oriented and 2000 km long rift system with a spreading rate decreasing from ~16 mm/yr in the south to ~7 mm/yr in the north. The morphology also changes along the rift axis: the south portion is a continuous and well-developed rift, clearly exposing oceanic crust, the central portion is characterized by deeps made by oceanic crust separated by shallower inter-trough zones, and the northern part contains more widely spaced and less obvious deeps with the transition to the continental crust not well defined. While the central Red Sea morphology has been extensively studied, the structure of the northern Red Sea and its link to the central Red Sea are still unclear. Indeed, the northern Red Sea rift is offset by 100 km to the central Red Sea axis by the still poorly understood Zabargad fracture zone.</p><p>Here we aim at improving the understanding of the volcano-tectonic structure of the axial part of the southern tip of the northern Red Sea that corresponds to the Mabahiss Deep. To this aim, we carried out multiple multibeam surveys with R/V Thuwal and R/V Kobi Ruegg to map the sea bottom to add to what had been done in earlier surveys. In addition, we obtained several sub-bottom profiling lines across and along the deep to better constrain the shallow sedimentary structure.</p><p>Our results show that the 15 km long, 9 km wide and 2250 m deep Mabahiss Deep along with the 800 m high and 5 km wide central volcano are the key prominent structures of the area. The deep is bordered by a series of Red Sea parallel normal faults on two sides forming a graben-like structure and thus suggesting a rift-like morphology. The central volcano is well preserved and has a 2 km wide summit caldera containing several volcanic cones and thus suggesting a permanent magmatic source underneath of a relatively young age. The ocean floor outside the deep and the volcanic edifice is mostly covered by salt flows, limiting structural analysis of the surrounding areas.</p><p>A comparison between the northern and central Red Sea suggests, although in both areas thick salt covers most of the ocean floor, that the axes have similar rift-like structures with stable axial volcanism. However, in the central Red Sea larger portions of the oceanic crust are free of salt and the deformation seems larger with more prominent faults that also affect the floor of the deeps and split apart volcanic edifices, enhancing the occurrence of diffused monogenic volcanic cones. Therefore, this might suggest, despite the central and northern Red Sea sharing the same structure and evolution, that the less volcanic and tectonic activity in the north probably reflects the decreasing spreading rate from south to north along the Red Sea.</p>

Demographic modelling of giant sea anemones: population stability and effects of mutualistic anemonefish in the Jordanian Red Sea

2017 ◽  
Vol 68 (11) ◽  
pp. 2145 ◽  
Author(s):  
Austin K. Dixon ◽  
Matthew J. McVay ◽  
Nanette E. Chadwick
Keyword(s):  
Body Size ◽  
Coral Reefs ◽  
Red Sea ◽  
Management Strategies ◽  
Population Level ◽  
Turnover Rates ◽  
Sea Anemones ◽  
Demographic Models ◽  
Demographic Modelling ◽  
Northern Red Sea

Giant sea anemones serve as important hosts for mutualistic anemonefish on Indo-Pacific coral reefs, but their population dynamics and turnover rates remain largely unknown. We used size-based demographic models to determine recruitment, changes in body size and mortality of bulb-tentacle anemones Entacmaea quadricolor and leathery anemones Heteractis crispa over 2years on coral reefs in the northern Red Sea, Jordan. Individuals recruited at consistent rates and grew rapidly until they reached ~300-cm2 tentacle crown surface area, then mostly remained static or shrank. Mortality rate decreased with body size, and the retention of large individuals strongly influenced population size. Individuals of H. crispa were more dynamic than those of E. quadricolor, possibly due to their hosting significantly smaller anemonefish. Both populations were abundant and stable but dynamic in terms of individuals, with estimated turnover times of only ~5 and 3years for E. quadricolor and H. crispa respectively. We conclude that some giant anemones may be short lived relative to their fish symbionts, and that stasis rates of large individuals disproportionately affect their populations. These results have implications for conservation management strategies of these major cnidarians on coral reefs, and indicate wide variation between species in the population-level effects of mutualistic interactions.

Porifera, one new species Suberea purpureaflava n. sp. (Demospongiae, Verongida, Aplysinellidae) from northern Red Sea coral reefs, with short descriptions of Red Sea Verongida and known Suberea species

Zootaxa ◽  
2011 ◽  
Vol 2994 (1) ◽  
pp. 60 ◽  
Author(s):  
JOCHEN GUGEL ◽  
MARIT WAGLER ◽  
FRANZ Brümmer
Keyword(s):  
New Species ◽  
Coral Reefs ◽  
Red Sea ◽  
Colour Change ◽  
Gulf Of Aqaba ◽  
Light Yellow ◽  
Dark Violet ◽  
One New Species ◽  
Northern Red Sea

A new verongid sponge (Suberea purpureaflava n. sp.) is described from Dahab, Gulf of Aqaba, in the northern Red Sea. It has a pronounced colour change (a dark red ectosome with whitish pore sieves and a light yellow choanosome in the living specimen changes to a uniform dark violet in the fixed state) and rather rare dendritic fibres with pith and bark and a diameter of about 110–165µm, with the pith occupying 80–90 % of the fibre. Especially the pore sieves were very striking in situ. The new species is compared to all verongid sponges so far recorded from the Red Sea and to all known and accepted Suberea species worldwide. An identification key to all known Suberea species is given. This new species record brings the number of Suberea species described to a total of 11.

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