Evaluation of the undersea habitats - Tektite II,Hydro-Lab,and Edalhab - for scientific saturation diving programs

Summary 1. The assessment of three undersea habitats — Tektite, Hydro-Lab and Edalhab — is based primarily upon the experience of the authors during a total of 62 man-days under saturation diving conditions while conducting biological research programs.2. A number of desirable and undesirable features were found in each habitat system; none of the individual systems included all of the desirable features.3. The paper discusses advantages and disadvantages of various features of the habitats including work and living areas, support equipment and techniques, operations and safety. The authors offer their experiences and suggestions to contribute to improvement of habitats and undersea diving operations.

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Bewertung der Unterwasser-Habitate Tektite II, Hydro-Lab und Edalhab für Programme des wissenschaftlichen Sättigungstauchens

Kurzfassung Eine kritische Bewertung der 3 Unterwasserlaboratorien Tektite II, Hydro-Lab und Edalhab wird auf Grund der praktischen Erfahrungen vorgenommen, die während eines längeren bemannten Einsatzes unter Sättigungsbedingungen im Rahmen eines biologischen Forschungsprogrammes in den USA gewonnen wurden. Keines der erprobten Unterwasser-Systeme erfüllte alle Erwartungen. Alle Habitate wiesen sowohl zufriedenstellende als auch mangelhafte Eigenschaften auf, die ausführlich diskutiert werden. Unter Berücksichtigung der bisher gemachten Erfahrungen werden zahlreiche Anregungen zur Verbesserung von Unterwasserlaboratorien und Empfehlungen für Taucheinsätze mitgeteilt.

     

Impact of the 2005 coral bleaching event on <Emphasis Type="Italic">Porites porites</Emphasis> and <Emphasis Type="Italic">Colpophyllia natans</Emphasis> at Tektite Reef,US Virgin Islands

A thermal stress anomaly in 2005 caused mass coral bleaching at a number of north-east Caribbean reefs. The impact of the thermal stress event and subsequent White-plague disease type II on Porites porites and Colpophyllia natans was monitored using a time series of photographs from Tektite Reef, Virgin Islands National Park, St. John. Over 92% of the P. porites and 96% of the C. natans experienced extensive bleaching (>30% of colony bleached). During the study, 56% of P. porites and 42% of C. natans experienced whole-colony mortality within the sample plots. While all whole-colony mortality of P. porites was directly attributed to coral bleaching, the majority (82%) of the C. natans colonies that experienced total mortality initially showed signs of recovery from bleaching, before subsequently dying from White-plague disease type II.     

L.D.H. and L.D.H. isoenzymes of the intra-uterine secretions of the cow during the estrous cycle

Uterine secretions were collected from 20 mature cows during estrus (day 0), metestrus (day 5), diestrus (day 10) and proestrus (day-1). Lactate dehydrogenase (LDH) and LDH isoenzymes activity were evaluated. No significant cyclic variations of LDH activity was found in the uterine secretions while the mean of the enzyme activity was higher during the estrogenic period of the cycle. The relative activity of LDH-1, LDH-2 and LDH-3 isoenzymes were higher during proestrus and estrus whereas LDH-5 activity was more important during metestrus. The LDH-3 seems to have the higher relative activity in uterine secretions of the cow.