Age and growth parameters of skates of the genus Bathyraja obtained between 2003-2005 along the Argentine continental shelf

In the last 20 years directed shark and ray fishery has increased alarmingly everywhere in the world. For most species though, no data on growth rate, mortality, fecundity and other life history aspects exist as of now and management of the fishery is therefore insufficient. Also there still exist methodological difficulties in the age determination of elasmobranchs fishes, a fact which complicates the investigation of growth parameters. This study tried to identify the best ageing methods and estimate growth parameters for ten skate species of the genus Bathyraja, all occurring in the southwest Atlantic in depths of 50m and more. 720 samples were collected on board of argentine research vessels in between 2003 and 2005. Crystal violet and a new staining method using potassium permanganate, both applied on sagittal sections of vertebral centra, proved to be most effective in enhancing the banding pattern in most of the species. Thorns were also tested and readings were consistent with the ones made on vertebral sections. Growth parameters could be derived for six species and for the other four estimates could be made. Growth rate as well as infinite length varied between species, with those attaining bigger sizes having lower growth rates. No latitudinal differences in growth rate could be detected but a comparison with samples from other studies showed that total lengths were always reported to be higher around the Malvinas Islands.

Natural resources on the Russian continental shelf: Foreign investors sought... on Russian terms. OSW Commentary No. 76, 2012-05-09

In recent weeks, Rosneft, a Russian state-owned oil company, has signed co-operation agreements with three Western corporations: America’s ExxonMobil, Italy’s Eni, and Norway’s Statoil. In exchange for access to Russian oil fields on the continental shelf as minority shareholders, these Western investors will finance and carry out exploration there. They will also offer to Rosnieft technology transfer, staff exchange and the purchase of shares in their assets outside Russia (for example in the North Sea or in South America). Rosneft’s deals with Western energy companies prove that the Russian government is resuming the policy of a controlled opening-up of the Russian energy sectors to foreign investors which it initiated in 2006. So far, investors have been given access to the Russian electric energy sector and some onshore gas fields. The agreements which have been signed so far also allow them to work on the Russian continental shelf. This process is being closely supervised by the Russian government, which has enabled the Kremlin to maintain full control of this sector. The primary goal of this policy is to attract modern technologies and capital to Russia and to gain access to foreign assets since this will help Russian corporations to reinforce their positions in international markets. The signing of the above agreements does not guarantee that production will commence. These are a high-risk projects. It remains uncertain whether crude can be extracted from those fields and whether its development will be cost-effective. According to estimates, the Russian Arctic shelf holds approximately 113 billion tonnes of hydrocarbons. The development of these fields, including building any necessary infrastructure, may consume over US$500 billion within 30 years. Furthermore, the legal regulations currently in force in Russia do not guarantee that foreign investors will have a share in the output from these fields. Without foreign support, Russian companies are unlikely to cope with such technologically complicated and extremely expensive investments. In the most optimistic scenario, the oil production in the Russian Arctic may commence in fifteen to twenty years at the earliest.

Distribution of molluscs on the Atlantic continental shelf off Southern Spanish Sahara, West Africa

Two hundred and seventy five mollusc species from the continental shelf off Southern Spanish Sahara (depth: 32-60 m) were identified. Their distribution pattern is strongly influenced by the nature of the bottom (firm substrate, shelter, stability of sediment) rather than other factors at that depth interval. This faunal assemblage shows great affinity to the Mediterranean and Lusitanian faunas, and comprises only few (22 %) exclusively Senegalese and species living south of Senegal.

Sand resources on the Inner Continental Shelf of the Cape Fear region, North Carolina /

"November 1977."