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Inhibition of photosyntheses by Trichodesmium in the Sargasso Sea
956
Oceanographic Abstracts
MCLEOD, W. C. and T. HSIEH, 1963. Experimental investigation of Ursell's theory of wavemaking by a roiling cylinder. Schiffstechnik, 10 (50): 17-22. Urselrs predictions of the amplitudes of surtace wa~es generated by a particular family of rolling cylinders are in fairly good agreement with experiment for relatively small angles of roll. For larger angles of roll, the agreement is not so good, but the theory may serve as an aid to finding the approximate value of the wave amplitude. The fact that the ratio of the wave-damping energy to the total-damping energy for the model of theoretically zero wave damping is so small in comparison with the others strongly emphasizes the applicability of Urselrs theory for predicting approximately the actual wave damping of cylindrical sections.
MCMANUS,D. A. and J. S. CREAGER, 1963. Physical and sedimentary environments on a large spitlike shoal. J. Geol., 71 (4): 498-512. Measurements of water temperature, salinity, transparency, current velocities, and sediment distribution are used to interpret the physical and sedimentary environments of a spitlike shoal extending eighty nautical miles north of the western tip of Seward Peninsula, Alaska. The shoal, covering approximately 2000 sq miles, is characterized by slopes of less than 31 ft/mile. Sediment-bearing coastal water passes northward through the Bering Strait and past the shoal at speeds of as much as 50 cm/sec. Four sedimentary environments have been recognized, and their significance with relation to the physical conditions is interpreted. The importance of seasonal variations is mentioned. MENZEL, DAVID W., 1962. Inhibition of photosyntheses by Trichodesmiurn in the Sargasso Sea. (Abstract). Ass. Island Mar. Labs., 4th Meet., Curafao, 18-20. Nov. 1962: 14. The blue-green alga, Trichodesmium thiebautii, is commonly found in nutrient impoverished tropical waters. Measurements were made of production rate of Trichodesmium independently of other phytoplankton by the use of light and dark oxygen bottles and its photosynthesis estimated by the method of Gaarder and Gran (1927). Oxygen production was usually lower in plants exposed to a 24 hr day that in those exposed for only 4 hr over noon to full sunlight. When varying quantities of plants were exposed to full sunlight for 2 hr., the more concentrated the plants the lower was their rate of oxygen production. These results suggested two possibilities: that Trichodesmium is extremely sensitive to handling and an accurate estimate of production would be impossible to obtain, or that the plants were exhibiting a toxic effect on their own species. To test whether Trichodesmium was exhibiting a toxic effect upon phytoplankton, varying amounts of filtrate from homogenized plants were added to (I) sterile cultures of Carteria (clone BT-2, WHOI) and (2) natural sea water, and their production rates measured by the C t4 method. In both (I) and (2) the results showed rather conclusively that Trichodesmiunl filtrate inhibited normal t4C uptake. METZLER, A. R., 1962. An untended digital data acquistion system. Proc. 2nd lnterindust. Oceanogr. Sym., Lockheed Ab'craft Corp., 3-10, An oceanographic buoy, with included instrument recording system, has been produced and tested which uniquely utilizes a variety of oceanographic sensors. The uniqueness of this system depends on the manner m which several types of sensor inputs can he handled by the data recording package. The present system utilizes the following type sensors: anemometer, wind-direction sensor, water temperature, Savonius Rotor Current Meters, and water current-direction sensors. Data storage is performed by a digital magnetic tape recorder with direct application to telemetry methods. The buoy philosophy used dictates the transducer method employed in each sensor and is pointed toward handling large amounts of oceanographic data from a single station.
MILLER, D., J. B. COLTON JR. and R. R. MARAK,1963. A study of the vertical distribution of larval haddock. J. Cons. Int. Exp. Mer., 28 (l): 37-49. A study of the vertical distribution of larval haddock at three locations on Georges Bank was made in May 1958, using a high-speed, multi-depth sampling technique. Each of three stations was occupied for two consecutive days, one 30 min tow being taken every 2 hr. Stations were marked by means of a free-drifting buoy in order that sampling would be restricted to a specific water mass. The results indicate that the sampling technique employed was successful in eliminating differences in day and night catches due to larval escapement. An analysis of larval distribution in terms of depth shows that although haddock, larvae occurred throughout at least the upper 50 m of the water column, maxin'.um concentrations were centred between 20 ar.d 30 m. Periodic changes in larval depth distributicn ere demonstrated. The relationship of these changes to periodic fluctuations in tl-~e depth of tl-.e thermccline is evident. Over 80 per cent of the larvae occurred within the confines of the thermocline. Some evidence from data collected at Station l suggests that very small larvae, 4-8 mm in length had a distinctly different distribution cccurring belcw tl',¢ thernzocline. Evidence to explain this disparity in distribution is lackin 8,
Oceanographic Abstracts
MCLEOD, W. C. and T. HSIEH, 1963. Experimental investigation of Ursell's theory of wavemaking by a roiling cylinder. Schiffstechnik, 10 (50): 17-22. Urselrs predictions of the amplitudes of surtace wa~es generated by a particular family of rolling cylinders are in fairly good agreement with experiment for relatively small angles of roll. For larger angles of roll, the agreement is not so good, but the theory may serve as an aid to finding the approximate value of the wave amplitude. The fact that the ratio of the wave-damping energy to the total-damping energy for the model of theoretically zero wave damping is so small in comparison with the others strongly emphasizes the applicability of Urselrs theory for predicting approximately the actual wave damping of cylindrical sections.
MCMANUS,D. A. and J. S. CREAGER, 1963. Physical and sedimentary environments on a large spitlike shoal. J. Geol., 71 (4): 498-512. Measurements of water temperature, salinity, transparency, current velocities, and sediment distribution are used to interpret the physical and sedimentary environments of a spitlike shoal extending eighty nautical miles north of the western tip of Seward Peninsula, Alaska. The shoal, covering approximately 2000 sq miles, is characterized by slopes of less than 31 ft/mile. Sediment-bearing coastal water passes northward through the Bering Strait and past the shoal at speeds of as much as 50 cm/sec. Four sedimentary environments have been recognized, and their significance with relation to the physical conditions is interpreted. The importance of seasonal variations is mentioned. MENZEL, DAVID W., 1962. Inhibition of photosyntheses by Trichodesmiurn in the Sargasso Sea. (Abstract). Ass. Island Mar. Labs., 4th Meet., Curafao, 18-20. Nov. 1962: 14. The blue-green alga, Trichodesmium thiebautii, is commonly found in nutrient impoverished tropical waters. Measurements were made of production rate of Trichodesmium independently of other phytoplankton by the use of light and dark oxygen bottles and its photosynthesis estimated by the method of Gaarder and Gran (1927). Oxygen production was usually lower in plants exposed to a 24 hr day that in those exposed for only 4 hr over noon to full sunlight. When varying quantities of plants were exposed to full sunlight for 2 hr., the more concentrated the plants the lower was their rate of oxygen production. These results suggested two possibilities: that Trichodesmium is extremely sensitive to handling and an accurate estimate of production would be impossible to obtain, or that the plants were exhibiting a toxic effect on their own species. To test whether Trichodesmium was exhibiting a toxic effect upon phytoplankton, varying amounts of filtrate from homogenized plants were added to (I) sterile cultures of Carteria (clone BT-2, WHOI) and (2) natural sea water, and their production rates measured by the C t4 method. In both (I) and (2) the results showed rather conclusively that Trichodesmiunl filtrate inhibited normal t4C uptake. METZLER, A. R., 1962. An untended digital data acquistion system. Proc. 2nd lnterindust. Oceanogr. Sym., Lockheed Ab'craft Corp., 3-10, An oceanographic buoy, with included instrument recording system, has been produced and tested which uniquely utilizes a variety of oceanographic sensors. The uniqueness of this system depends on the manner m which several types of sensor inputs can he handled by the data recording package. The present system utilizes the following type sensors: anemometer, wind-direction sensor, water temperature, Savonius Rotor Current Meters, and water current-direction sensors. Data storage is performed by a digital magnetic tape recorder with direct application to telemetry methods. The buoy philosophy used dictates the transducer method employed in each sensor and is pointed toward handling large amounts of oceanographic data from a single station.
MILLER, D., J. B. COLTON JR. and R. R. MARAK,1963. A study of the vertical distribution of larval haddock. J. Cons. Int. Exp. Mer., 28 (l): 37-49. A study of the vertical distribution of larval haddock at three locations on Georges Bank was made in May 1958, using a high-speed, multi-depth sampling technique. Each of three stations was occupied for two consecutive days, one 30 min tow being taken every 2 hr. Stations were marked by means of a free-drifting buoy in order that sampling would be restricted to a specific water mass. The results indicate that the sampling technique employed was successful in eliminating differences in day and night catches due to larval escapement. An analysis of larval distribution in terms of depth shows that although haddock, larvae occurred throughout at least the upper 50 m of the water column, maxin'.um concentrations were centred between 20 ar.d 30 m. Periodic changes in larval depth distributicn ere demonstrated. The relationship of these changes to periodic fluctuations in tl-~e depth of tl-.e thermccline is evident. Over 80 per cent of the larvae occurred within the confines of the thermocline. Some evidence from data collected at Station l suggests that very small larvae, 4-8 mm in length had a distinctly different distribution cccurring belcw tl',¢ thernzocline. Evidence to explain this disparity in distribution is lackin 8,