The Baikal seal (Phoca sibirica) is confined to Lake Baikal in southern Siberia. The breeding distribution of seals in winter, when the lake is frozen over, is fairly well known, whereas their movements and foraging behaviors have been relatively unstudied. With satellite‐linked radio transmitters, we documented the movements and dive patterns of four juvenile Baikal seals from autumn through spring. The seals moved extensively in the lake, each covering minimal distances of 400–1,600 km between September and early May. They spent little time hauled out from September through May and, apparently, dived continuously. Dives were mostly to depths of lo‐50 m, though a few exceeded 300 m. Most lasted between 2 and 6 mm, within theoretical aerobic dive limits, although a few exceeded 40 min. The exceptionally long dives occurred while the seals were in areas of extensive ice cover, suggesting that they were, perhaps, under ice‐pilotage in search of breathing holes rather than foraging dives. Otherwise, the dive performances of these Baikal seals were, relative to body mass, similar to those of other well‐studied phocids. Movements and dive patterns of seals appeared to be primarily associated with seasonal and die1 movements of their primary prey, golomyanka and sculpins, and secondarily correlated with patterns of ice formation and thaw.

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Epitaxial grown thick layers (>IO0 pm) of high resistivity silicon (Epi-Si) have been investigated as a possible candidate of radiation hardened material for detectors for high-energy physics. As grown Epi-Si layers contain high concentration (up to 2.1Oi2 cm") of deep levels compared with that in standard high resistivity bulk Si. After irradiation of test diodes by protons (EP = 24 GeV) with a fluence of 1.5-10'' cm-', no additional radiation induced deep traps have been detected. A reasonable explanation is that there is a sink of primary radiation induced defects (interstitial and vacancies), possibly by as-grown defects, in epitaxial layers. The "sinking" process, however, becomes non-effective at high radiation fluences (loJ4 cm-') due to saturation of epitaxial defects by high concentration of radiation induced ones. As a result, at neutron fluence of l-10i4cm'2 the deep level spectrum corresponds to well-known spectrum of radiation induced defects in high resistivity bulk Si. The net effective concentration in the space charge region equals to 3.10i2 cm-3 after 3 months of room temperature storage and reveals similar annealing behavior for epitaxial as compared to bulk silicon.