One-pot near-ambient temperature syntheses of aryl(difluoroenol) derivatives from trifluoroethanol

Difluoroalkenylzinc reagents prepared from 1-(2’-methoxy-ethoxymethoxy)-2,2,2-trifluoroethane and 1-(N,N-diethylcarbamoyloxy)-2,2,2-trifluoroethane at ice bath temperatures, underwent Negishi coupling with a range of aryl halides in a convenient one pot procedure. While significant differences between the enol acetal and carbamate reagents were revealed, the Negishi protocol compared very favourably with alternative coupling procedures in terms of overall yields from trifluoroethanol

Speckled Catshark Halaelurus boesemani

The Speckled Catshark (Halaelurus boesemani) is a relatively small (to 48 cm total length), data-poor catshark. It is known from a limited number of specimens collected from four locations along an ~900 km stretch of Somali coastline. It occurs on continental and insular shelves at depths of 29-91 m. Its entire distribution has been subject to at least four decades of unregulated commercial benthic trawling; shelf-occurring catsharks are very susceptible to capture in this fishing gear. The new Somali Fisheries Law bans benthic trawling, but it is suspected that past declines have already occurred given the long history of unregulated fishing across its entire range. Furthermore, enforcement of this new regulation will be a challenge. While specific data are lacking, a population size reduction of 30-50% is suspected over the past three generations (~45 years) based on actual levels of exploitation (bycatch) and the species is assessed as Vulnerable A2d. It is of concern that there have been no records since 1991, although it is acknowledged that research and monitoring have been limited in Somalia. Further investigation of this species is required to accurately define its range, biology, extent of catches in local fisheries and levels of declines. This assessment should be revisited as soon as this is available

Smallbelly Catshark Apristurus indicus

The Speckled Catshark (Halaelurus boesemani) is a relatively small (to 48 cm total length), data-poor catshark. It is known from a limited number of specimens collected from four locations along an ~900 km stretch of Somali coastline. It occurs on continental and insular shelves at depths of 29-91 m. Its entire distribution has been subject to at least four decades of unregulated commercial benthic trawling; shelf-occurring catsharks are very susceptible to capture in this fishing gear. The new Somali Fisheries Law bans benthic trawling, but it is suspected that past declines have already occurred given the long history of unregulated fishing across its entire range. Furthermore, enforcement of this new regulation will be a challenge. While specific data are lacking, a population size reduction of 30-50% is suspected over the past three generations (~45 years) based on actual levels of exploitation (bycatch) and the species is assessed as Vulnerable A2d. It is of concern that there have been no records since 1991, although it is acknowledged that research and monitoring have been limited in Somalia. Further investigation of this species is required to accurately define its range, biology, extent of catches in local fisheries and levels of declines. This assessment should be revisited as soon as this is available

Troubled Waters: Threats and Extinction Risk of the Sharks, Rays and Chimaeras of the Arabian Sea and Adjacent Waters

The extinction risk of sharks, rays and chimaeras is higher than that for most other vertebrates due to low intrinsic population growth rates of many species and the fishing intensity they face. The Arabian Sea and adjacent waters border some of the most important chondrichthyan fishing and trading nations globally, yet there has been no previous attempt to assess the conservation status of species occurring here. Using IUCN Red List of Threatened Species Categories and Criteria and their guidelines for application at the regional level, we present the first assessment of extinction risk for 153 species of sharks, rays and chimaeras. Results indicate that this region, home to 15% of described chondrichthyans including 30 endemic species, has some of the most threatened chondrichthyan populations in the world. Seventy-eight species (50.9%) were assessed as threatened (Critically Endangered, Endangered or Vulnerable), and 27 species (17.6%) as Near Threatened. Twenty-nine species (19%) were Data Deficient with insufficient information to assess their status. Chondrichthyan populations have significantly declined due to largely uncontrolled and unregulated fisheries combined with habitat degradation. Further, there is limited political will and national and regional capacities to assess, manage, conserve or rebuild stocks. Outside the few deepsea locations that are lightly exploited, the prognosis for the recovery of most species is poor in the near-absence of management. Concerted national and regional management measures are urgently needed to ensure extinctions are avoided, the sustainability of more productive species is secured, and to avoid the continued thinning of the regional food security portfolio

Putting sharks on the map: A global standard for improving shark area-based conservation

Area-based conservation is essential to safeguard declining biodiversity. Several approaches have been developed for identifying networks of globally important areas based on the delineation of sites or seascapes of importance for various elements of biodiversity (e.g., birds, marine mammals). Sharks, rays, and chimaeras are facing a biodiversity crisis with an estimated 37% of species threatened with extinction driven by overfishing. Yet spatial planning tools often fail to consider the habitat needs critical for their survival. The Important Shark and Ray Area (ISRA) approach is proposed as a response to the dire global status of sharks, rays, and chimaeras. A set of four globally standardized scientific criteria, with seven sub-criteria, was developed based on input collated during four shark, biodiversity, and policy expert workshops conducted in 2022. The ISRA Criteria provide a framework to identify discrete, three-dimensional portions of habitat important for one or more shark, ray, or chimaera species, that have the potential to be delineated and managed for conservation. The ISRA Criteria can be applied to all environments where sharks occur (marine, estuarine, and freshwater) and consider the diversity of species, their complex behaviors and ecology, and biological needs. The identification of ISRAs will guide the development, design, and application of area-based conservation initiatives for sharks, rays, and chimaeras, and contribute to their recovery

7-Selenabicyclo2.2.1heptane

Thermolysis of a benzene solution of N-4-(p-(methoxybenzyl)seleno) cyclohexanoyl-N,S-dimethyldithiocarbonate affords the hitherto unknown 7-selenabicyclo2.2.1heptane in 48% conversion and in 20% yield after chromatography. G3(MP2)-RAD calculations predict a rate constant of 5 X 104 s-1 at 80 °C (3.8 X 106 s -1 at 200 °C) for the intramolecular homolytic substitution process involved in this cyclization