Satellite Tracking of Post-nesting Green Sea Turtles (Chelonia mydas) From Ras Baridi, Red Sea

Identifying migratory pathways and linking nesting sites to foraging areas is essential for effective conservation management of migratory species, such as marine turtles. Post-nesting marine turtles disperse from their nesting sites to multiple foraging areas located from a few to hundreds of kilometers away. Over a six-year period 16 female green turtles (Chelonia mydas) were equipped with satellite transmitters between October and December of five nesting seasons to determine their migratory routes from their nesting area at five contiguous beaches at Ras Baridi, Saudi Arabia, to their foraging areas. All foraging areas for these turtles were located in shallow coastal areas or in shallow areas around offshore islands within the Red Sea basin. The majority (n = 12) migrated through the shallow (<200 m) water along the coastal margin to reach foraging areas located to the North (n = 4) and South (n = 12) of the nesting site. Four turtles crossed the deep trough of the Red Sea during their journeys. Ten of the 16 turtles migrated to foraging areas within the territorial waters of Saudi Arabia. The other six turtles migrated to foraging areas in Egypt (n = 4) and Eritrea (n = 2). These 16 turtles traveled between 130 and 1749 km from their nesting site to foraging areas located in the northern, middle and southern parts of the Red Sea. Because these turtles utilized foraging areas in at least three countries (Saudi Arabia, Egypt, and Eritrea) and one passed through the territorial waters of Sudan, conservation and management of green turtles in the Red Sea requires multinational cooperation to address anthropogenic threats in the region.

Managing the Hazards of Aeolian, Fluvial and Coastal Erosion in Gudhi Area-Northern Kuwait Bay

Kuwait Institute for Scientific Research plans to set up some research facilities within the Gudhi area, which lies north of the coastal spill of Kuwait Bay. The area is about 653,000 m2, the region highly sensitive from an environmental perspective and ecological. It is a coastal strip dominated by rich fauna and flora mainly Nitraria retusa forming large nabkhas that attract many wildlife scientists. The presence of nabkhas is a good indicator of fluvial and aeolian activities in the area. The establishment of infrastructures within this area is anticipated to cause significant damage to wildlife. Additionally, any future infrastructures in the area is under the following threats: 1-S and encroachment as it is located within an active wind corridor. 2-Fluvial action during flood seasons as it is located at downstream of Jal Al-Zur watershed. 3-The wave erosion along 1200m coastal margin. As an important role of KISR is the attention and care regarding the environmental aspects associated with project actions, therefore, it is proposed that a proper scientific research project should be implemented prior to the establishment of any infrastructure development. The main objective of this study is to assess and control hazards in the Gudhi area by implementation of native plants and mangroves landscape design. Assessment and monitoring of fauna and flora have provided initial information on existing vegetation, soil properties that are considered important to quantify ecological conditions prior to actual vegetation plantation establishment or restoration effort. Nitraria and Lycium populations were found the most proper in controlling hazards of mobile sand and flush floods for the study area.

IMPORTÂNCIA DE MICROHABITATS NA OCORRÊNCIA DE GÊNEROS DE EPHEMEROPTERA E TRICHOPTERA EM UMA ILHA NO RIO XINGU

IMPORTANCE OF MICROHABITATS IN THE OCCURRENCE OF EPHEMEROPTERA AND TRICHOPTERA SPECIES IN AN ISLAND IN RIO XINGU. This work described the abundance, richness and composition of genera and the functional food groups (GFA) of Ephemeroptera and Trichoptera (ET), in different microhabitats of a fluvial island, in Volta Grande of the Xingu River, Brazilian Amazon. Aquatic insects were collected from 30 samples located in puddles situated in the interior of the island (rocks as substrate); and another 30 samples located in the coastal margin of the island (pebble as substrate). The different facets of diversity (abundance, richness and composition of genera and GFA) were compared between puddle samples with rock substrate and those from the coastal region with pebble substrate. In total, 56 individuals were collected, distributed in 15 genera ET. The greatest estimated genera richness and the largest number of individuals occurred in the rocks of the puddle environments. The composition of genera differed between the rocks in the puddle environments and the pebbles in the coastal environments, with the community of the latter being more homogeneous. There were more scraper organisms distributed predominantly in the rocks of the puddle environments and filtering organisms arranged predominantly in the pebbles of the coastal environments. The distribution of scrapers is related to the availability of food, since the island has little vegetation and the light on the rocks is favorable for colonization by biofilm, its main food resource. In the coastal region, the greater distribution of filters is related to the greater number of fine particles suspended in water, its main food resource. The results demonstrate that even in spatially close environments, such as on a small island, differences in the availability of food resources in different microhabitats can influence the distribution in multiple facets of diversity. Thus, even in dynamic environments such as large rivers, maintaining microhabitats is important for aquatic insect communities.

Coastal complexity of the Antarctic continent

The Antarctic outer coastal margin (i.e. the coastline itself or the terminus or front of ice shelves, whichever is adjacent to the ocean) is a key interface between the ice sheet and terrestrial environments and the Southern Ocean. Its physical configuration (including both length scale of variation, orientation, and aspect) has direct bearing on several closely associated cryospheric, biological, oceanographical, and ecological processes, yet no study has quantified the coastal complexity or orientation of Antarctica's coastal margin. This first-of-a-kind characterization of Antarctic coastal complexity aims to address this knowledge gap. We quantify and investigate the physical configuration and complexity of Antarctica's circumpolar outer coastal margin using a novel technique based on ∼ 40 000 random points selected along a vector coastline derived from the MODIS Mosaic of Antarctica dataset. At each point, a complexity metric is calculated at length scales from 1 to 256 km, giving a multiscale estimate of the magnitude and direction of undulation or complexity at each point location along the entire coastline. Using a cluster analysis to determine characteristic complexity “signatures” for random nodes, the coastline is found to comprise three basic groups or classes: (i) low complexity at all scales, (ii) most complexity at shorter scales, and (iii) most complexity at longer scales. These classes are somewhat heterogeneously distributed throughout the continent. We also consider bays and peninsulas separately and characterize their multiscale orientation. This unique dataset and its summary analysis have numerous applications for both geophysical and biological studies. All these data are referenced by https://doi.org/10.26179/5d1af0ba45c03 (Porter-Smith et al., 2019) and are available free of charge at http://data.antarctica.gov.au (last access: 7 June 2021).

Amplified Impact of Climate Change on Fine-Sediment Delivery to a Subsiding Coast, Humboldt Bay, California

In Humboldt Bay, tectonic subsidence exacerbates sea-level rise (SLR). To build surface elevations and to keep pace with SLR, the sediment demand created by subsidence and SLR must be balanced by an adequate sediment supply. This study used an ensemble of plausible future scenarios to predict potential climate change impacts on suspended-sediment discharge (Qss) from fluvial sources. Streamflow was simulated using a deterministic water-balance model, and Qss was computed using statistical sediment-transport models. Changes relative to a baseline period (1981–2010) were used to assess climate impacts. For local basins that discharge directly to the bay, the ensemble means projected increases in Qss of 27% for the mid-century (2040–2069) and 58% for the end-of-century (2070–2099). For the Eel River, a regional sediment source that discharges sediment-laden plumes to the coastal margin, the ensemble means projected increases in Qss of 53% for the mid-century and 99% for the end-of-century. Climate projections of increased precipitation and streamflow produced amplified increases in the regional sediment supply that may partially or wholly mitigate sediment demand caused by the combined effects of subsidence and SLR. This finding has important implications for coastal resiliency. Coastal regions with an increasing sediment supply may be more resilient to SLR. In a broader context, an increasing sediment supply from fluvial sources has global relevance for communities threatened by SLR that are increasingly building resiliency to SLR using sediment-based solutions that include regional sediment management, beneficial reuse strategies, and marsh restoration.

Mesozooplankton biomass, grazing and trophic structure in the bluefin tuna spawning area of the oceanic Gulf of Mexico

We investigated size-fractioned biomass, isotopes and grazing of mesozooplankton communities in the larval habitat of Atlantic bluefin tuna (ABT) in the oceanic Gulf of Mexico (GoM) during the peak spawning month of May. Euphotic-zone biomass ranged from 101 to 513 mg C m−2 during the day and 216 to 798 mg C m−2 at night. Grazing varied from 0.1 to 1.0 mg Chla m−2 d−1, averaging 1–3% of phytoplankton Chla consumed d−1. Carnivorous taxa dominated the biomass of > 1-mm zooplankton (78% day; 60% night), while only 13% of smaller zooplankton were carnivores. δ15N enrichment between small and large sizes indicates a 0.5–0.6 trophic-step difference. Although characteristics of GoM zooplankton are generally similar to those of remote oligotrophic subtropical regions, zooplankton stocks in the ABT larval habitat are disproportionately high relative to primary production, compared with HOT and BATS averages. Growth-grazing balances for phytoplankton were resolved with a statistically insignificant residual, and trophic fluxes from local productivity were sufficient to satisfy C demand of suspension feeding mesozooplankton. While carnivore C demand was met by local processes in the central GoM, experiments closer to the coastal margin suggest the need for a lateral subsidy of zooplankton biomass to the oceanic region.

3D modelling of Isbræ-type glaciers and temperate-zone processes

<p>The majority of Greenland’s outlet glaciers are Isbræ-type, with high driving stresses, steep surface slopes, flow through deep channels, and with a basal layer of temperate ice theorised to thicken towards the coastal margin. Understanding the formation processes and thermodynamic influence of this temperate ice is important as limited laboratory testing indicates temperate ice has a viscosity 5-10 times lower than cold ice with no liquid phase. Furthermore, limited field data suggests lower rates of deformation within basal temperate ice than in the cold ice directly overlying it, which is presently unexplained. Here, we present preliminary results from a 3D finite-element model of an idealised Isbrae-type glacier built with Elmer/Ice, incorporating water-content-dependent ice viscosity, basal melting, and a parameterization of basal crevassing, and use it to investigate the formation and thermodynamic behaviour of temperate ice in response to varying bedforms and model parameters. We find that the observed decrease in strain in temperate ice close to the glacier base can be explained by a high strain area close to the cold-temperate transition zone. We further compare our model results to temperate ice variability observed at Sermeq Kujalleq (Store Glacier) to determine key temperate ice parameters requiring further investigation. These results provide a more complete understanding of the heterogeneous ice deformation behind the fast movement of Greenland’s Isbræ-type glaciers and can therefore help to improve predictions of future glacier flow.</p>

Kevin Barry’s Atlantic Drift

Kevin Barry is a short story writer, novelist, dramatist, and editor, with Olivia Smith, of Winter Papers, an annual anthology of contemporary Irish writing. His work is steeped in music, film, and television, and echoes with their influence. Underpinning this is an attachment to writers like Dermot Healy and John McGahern, both novelists whose importance to a writer like Barry makes all the more sense from a coastal, and an archipelagic, perspective. His binding theme is disappointment and his lyricism is braided into the tragic perspective his characters, and his narrators, have of the human condition, which is for the most part a tilting balance between anxiety and drink. These edgy narratives are often set in wet weather by the sea and as so often in this book, the coastal margin operates as a hydroscape in which the boundaries between innocence and experience fragment and shift.