Sea turtles are vulnerable to climate change since their reproductive output is influenced by incubating temperatures, with warmer temperatures causing lower hatching success and increased ...feminization of embryos. Their ability to cope with projected increases in ambient temperatures will depend on their capacity to adapt to shifts in climatic regimes. Here, we assessed the extent to which phenological shifts could mitigate impacts from increases in ambient temperatures (from 1.5 to 3°C in air temperatures and from 1.4 to 2.3°C in sea surface temperatures by 2100 at our sites) on four species of sea turtles, under a “middle of the road” scenario (SSP2‐4.5). Sand temperatures at sea turtle nesting sites are projected to increase from 0.58 to 4.17°C by 2100 and expected shifts in nesting of 26–43 days earlier will not be sufficient to maintain current incubation temperatures at 7 (29%) of our sites, hatching success rates at 10 (42%) of our sites, with current trends in hatchling sex ratio being able to be maintained at half of the sites. We also calculated the phenological shifts that would be required (both backward for an earlier shift in nesting and forward for a later shift) to keep up with present‐day incubation temperatures, hatching success rates, and sex ratios. The required shifts backward in nesting for incubation temperatures ranged from −20 to −191 days, whereas the required shifts forward ranged from +54 to +180 days. However, for half of the sites, no matter the shift the median incubation temperature will always be warmer than the 75th percentile of current ranges. Given that phenological shifts will not be able to ameliorate predicted changes in temperature, hatching success and sex ratio at most sites, turtles may need to use other adaptive responses and/or there is the need to enhance sea turtle resilience to climate warming.
Sea turtles are vulnerable to climate change and their ability to cope with projected increases in temperatures will depend on their capacity to adapt to shifts in climatic regimes. We assessed the extent to which phenological shifts could mitigate impacts from increases in temperatures on four species of sea turtles. Expected shifts in nesting will not be sufficient to maintain current incubation temperatures at 7 (29%) of our sites, hatching success rates at 10 (42%) of our sites, with current trends in hatchling sex ratio being able to be maintained at half of the sites.
The study aimed to confirm the presence of historic oyster banks of Qatar and code the biotopes present. The research also collated historical records and scientific publications to create a timeline ...of fishery activity. The oyster banks where once an extremely productive economic resource however, intense overfishing, extreme environmental conditions and anthropogenic impacts caused a fishery collapse. The timeline highlighted the vulnerability of ecosystem engineering bivalves if overexploited. The current status of the oyster banks meant only one site could be described as oyster dominant. This was unexpected as the sites were located in areas which once supported a highly productive oyster fishery. The research revealed the devastating effect that anthropogenic impacts can have on a relatively robust marine habitat like an oyster bed and it is hoped these findings will act as a driver to investigate and map other vulnerable habitats within the region before they too become compromised.
•The first biotope classification of oyster banks of Qatar•Oyster densities seriously diminished•Oyster fishery collapse in 1950’s•Overfishing, extreme environmental conditions, anthropogenic impacts resulted in dramatic habitat change.
The outwelling paradigm argues that mangrove and saltmarsh wetlands export much excess production to downstream marine systems. However, outwelling is difficult to quantify and currently 40–50% of ...fixed carbon is unaccounted for. Some carbon is thought outwelled through mobile fauna, including fish, which visit and feed on mangrove produce during tidal inundation or early life stages before moving offshore, yet this pathway for carbon outwelling has never been quantified. We studied faunal carbon outwelling in three arid mangroves, where sharp isotopic gradients across the boundary between mangroves and down-stream systems permitted spatial differentiation of source of carbon in animal tissue. Stable isotope analysis (C, N, S) revealed 22–56% of the tissue of tidally migrating fauna was mangrove derived. Estimated consumption rates showed that 1.4% (38 kg C ha−1 yr−1) of annual mangrove litter production was directly consumed by migratory fauna, with <1% potentially exported. We predict that the amount of faunally-outwelled carbon is likely to be highly correlated with biomass of migratory fauna. While this may vary globally, the measured migratory fauna biomass in these arid mangroves was within the range of observations for mangroves across diverse biogeographic ranges and environmental settings. Hence, this study provides a generalized prediction of the relatively weak contribution of faunal migration to carbon outwelling from mangroves and the current proposition, that the unaccounted-for 40–50% of mangrove C is exported as dissolved inorganic carbon, remains plausible.
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•The unquantified role of migratory fauna in the fate of carbon, means that mangrove carbon budgets are unresolved.•We quantified the faunal biomass exiting mangroves and used energy budgets and isotopic dietary tracers.•We found that less than 1% of mangrove litter production is actually faunally outwelled.•We predict that the proportion of faunally-outwelled carbon is likely to be similar in other mangroves•Our results support the current hypothesis that 40-50% of mangrove production is exported as dissolved inorganic carbon.
The northwestern Indian Ocean hosts globally crucial marine biodiversity, which is relatively understudied. There has, however, been significant research and conservation effort focused on marine ...turtles across the region in recent decades. We undertook an exhaustive review of 251 relevant publications to extract and collate the current information concerning marine turtles. To ensure completeness, we received input on a preliminary draft from a large group of experts who have worked extensively in the region. Data presented here are from all 13 countries with significant coastlines in the region (Bahrain, Djibouti, Egypt, Eritrea, Iran, Kuwait, Oman, Qatar, Saudi Arabia, Somalia, Sudan, United Arab Emirates, and Yemen) on occurrence, nesting biology, morphology, foraging areas, population status, threats, and relevant national legislation and international conservation strategies. The experts independently provided details on what they felt were the (1) most significant threats to marine turtles, (2) most critical knowledge gaps for marine turtle ecology, (3) impediments to practical conservation, and (4) essential strengths and opportunities in the region.
Projected climate change is forecasted to have significant effects on biological systems worldwide. Marine turtles in particular may be vulnerable, as the sex of their offspring is determined by ...their incubating temperature, termed temperature-dependent sex determination. This study aimed to estimate historical, and forecast future, primary sex ratios of hawksbill turtle
Eretmochelys imbricata
hatchlings at an important nesting ground in northeastern Qatar. Incubation temperatures from the Arabian/Persian Gulf were measured over 2 nesting seasons. Climate data from same period were regressed with nest temperatures to estimate incubation temperatures and hatchling sex ratios for the site from 1993 to 2100. Future hatchling sex ratios were estimated for 2 climate forecasts, one mid-range (SSP245) and one extreme (SSP585). Historical climate data showed female-biased sex ratios of 73.2 ± 12.1% from 1993 to 2017. Female biases from 2018 to 2100 averaged 85.7% ± 6.7% under the mid-range scenario and 87.9% ± 5.4% under the high-range scenario. In addition, predicted female hatchling production was >90% from 2054 and 2052 for SSP245 and SSP585, respectively. These results show that hawksbill primary sex ratios in Qatar are at risk of significant feminization by the year 2100 and that hawksbill turtle incubation temperatures in an extreme, understudied environment are already comparable to those predicted in tropical rookeries during the latter half of the 21
st
century. These results can help conservationists predict primary sex ratios for hawksbill turtles in the region in the face of 21
st
-century climate change.
Total mercury (THg) and methylmercury (MeHg) were recorded in the commercial demersal fish Lethrinus nebulosus, caught from six locations in Qatar EEZ (Exclusive Economic Zone). Concentrations of THg ...decreased in the order: liver˃muscle˃gonad. THg concentrations in fish tissue ranged from 0.016ppm in gonad to 0.855ppm (mgkg−1w/w) in liver tissues, while concentrations in muscle tissue ranged from 0.24 to 0.49ppm (mgkg−1w/w) among sampling sites. MeHg concentrations were used to validate food web transfer rate calculations. Intake rates were calculated to assess the potential health impact of the fish consumption. There is no major threat to human health from the presence of Hg in L. nebulosus, based upon reasonable consumption patterns, limited to no more than three meals of L. nebulosus per week.
•Hg in fish was within allowable concentrations and poses no threat to public health.•Concentrations of Hg decreased in the order: liver˃muscle˃gonad.•Consumers are encouraged to limit themselves to no more than three meals of Sha'ri per week.•Eating small fish would be safer than larger and older ones.
The Prometheus project is seeking to create a virtual studio production chain. This paper discusses the technologies that are being investigated and in particular the research in progress within the ...Content and Coding Laboratory in BTexact Technologies. Also presented are the historical changes in the production of real and animated performances and how Prometheus and current trends can have an impact upon this. Two areas are identified where further study is required to ensure believability and coherence when virtual performances are created from reusable digital components. PUBLICATION ABSTRACT
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