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Acoustic propagation in shallow water overlying a consolidated bottom
200
Oceanographic Abstracts
HOBSON L.A., W.J. MORRIS and K. T. P1RQUET, 1976. Theoretical and experimental analysis of the J4C technique and its use in studies of primary production. J. Fish. Res. Board Can., 33 (8): 1715-1721. Theoretical and experimental field studies of ~4C uptake by marine phytoplankton were carried out to determine environmental conditions required for the technique to measure net photosynthesis. Results of theoretical studies indicate that rapidly metabolizing populations (rate constants for gross photosynthesis and respiration of 0.1 h -~ and 0.007 h -~, respectively) may saturate with ~4C after about 30 h of continuous irradiation, Results of field studies indicate that a minimum of 24 h are required for net photosynthesis to be measured when daily irradiations exceed 20 cat cm -2 and nutrient limitation of photosynthesis does not occur. Additional measurements that may be made to aid in interpreting results obtained by the ~4C technique are briefly discussed. HOLLIBAUGH J. T., 1976. The biological degradation of arginine and glutamic acid in seawater in relation to the growth of phytoplankton. Mar. Biol., 36 (4): 303-312. The responses of natural summer coastal plankton communities to low-level additions (10-s to 10 -7 M) of arginine and glutamic acid has been followed by in vivo measurement of chlorophyll fluorescence. This technique is capable of detecting a response to a 10-6 M enrichment under most conditions. The time sequence of the response varied with the amino acid used and with the enantiomeric form of the amino acid. Ammonia and carbon dioxide were liberated before the increase in chlorophyll fluorescence occurred. Liberation of ammonia in a dark bottle from L-arginine was from 75 to 85% of the theoretical yield. Microautoradiography using 14C L-arginine or L-glutamic acid at 10-7 M showed heavy labeling associated with fecal pellets and detrital aggregates. Phytoplankton cells were not appreciably labeled. The evidence suggests that bacteria are important in the cycling of these compounds. HOPPE H.-G., 1976. Determination and properties of actively metabolizing heterotrophic bacteria in the sea, investigated by means of microautoradiography. Mar. Biol., 36 (4): 291-302. Substrate transformation and microbial biomass production in aquatic ecosystems depend mainly on the total number of actively metabolizing heterotrophic bacteria. The most common methods used concern the determination of either the colony-forming bacteria or the total number of bacteria including autotrophs and inactive organisms. A micro-autoradiographic method is presented which enables the substrate uptake of single bacteria by means of 3H-amino-acid mixture and Nuclepore filters to be determined. The standardization procedure rew,'aled the greatest success after 3 h incubation with 10/aCi/ml tritiated amino-acid mixture and an exposure of 14 days to the X-r,'ty film. Preliminary experiments showed inactivation of an active fresh-water population from 100% to 0.6% within 3 h at 28 °/70 S. With increasing distance from the shore, the number of colony-forming units decreases from 6 to 0.01% of the total numger of active heterotrophic bacteria. It is concluded from the results that the fraction of very small heterotrophic bacteria which cannot be cultured on nutrient media is responsible for the continuous breakdown of organic matter in offshore regions of the s~a. HORNIBROOK N. de B., 1976. Globorotalia truncatulinoides and the Pliocene-Pleistoeene boundary in northem Hawkes Bay New Zealand. Progress in micropaleontology, 83-102. Micropaleontology Press, N. Y. A 1,000-fuot (300-m) drill hole in thick, rapidly deposited, marine Pliocene-Pleistocene beds at Wairoa, to investigate the zone of overlap of Globorotalia tosaensis and G. truncatulinoides provided a detailed sequence containing both forms, through the upper 850 feet (260 m ) of pumiceous siltstone but did not penetrate the total interval of overlap. The ratio of keeled to non-keeled forms is variable, although the non-keeled form becomes more predominant with increasing depth. The two forms appear to be morphotopical extremes of a single species. Populations between 249 feet (75 m ) and 552 feet (170 m ) consist of sparse, small, sinistrally coiled individuals, whereas above and below this interval they are more abundant, larger, and dextrally coiled. The earliest specimens of G. tosaensis occur within the upper part of the range-zone of Obicides molestus (Waipipian Stage, Late Pliocene) but not earlier. There is a close match of bolh foraminifera and calcareous nannofosslls with the relatively thick overlap zone of G. tosaensis and G. truneatulinoides in DSDP S te 206 in the New Caledonia Basin. The last discoasters occur well above the earliest G. truncatulinoides in both localities, and there is an interval of more than 2,000 feet (600 m ) in the Wairoa Syncline within which the Plio-Pleistocene boundary could be placed. Correlation with the Calabrian is uncertain. The ranges of Globorotalia cr~ssula and G. crassafi~rmis are useful locally. Globorotalia crassaformis coils dextrally below 692 feet and sinistrally above that level. Changes in faunal diversity ar d in coiling direction of Globorotalia pachyderrna and G. truncatulinoides indicate alternations of warm and cool periods. INGENITO FRANK and S. N. WOLF, 1976. Acoustic propagation in shallow water overlying a consolidated bottom. J. acoust. S~c. Am., 60 (3): 611-617. An experiment designed to measure normal mode amplitude functions and attenuation coefficients was conducted in shallow water on Campeche Bank off the Yucatar Peninsula. Measurements were made at two locations on the bank in water of about 30 m in depth over a bottom consisting of consolidated limestone having a measured and sound velocity of 1,900 m/sec. Pulsed cw signals
Oceanographic Abstracts
201
with frequencies of 400, 750, and 1,500 Hz were used. Theoretical calculations of the mode amplitude functions using a fluid model of the bottom were found to agree well with the measurements. In order to reconcile the measured mode attenuation coefficients with theory, it was necessary to assume that the shear velocity of the bottom was 1,000 m/sec. The latter is lower than the minimum sound velocity in the water column so that the generation of propagating shear waves in the bottom was the dominant attenuation mechanism. Significant differences in the measured mode attenuation coefficients at the two stations were explained by the deepening of the low velocity channel at the bottom of the water column. INGLE J. C. Jr. and E. J. SCHNACK, 1975. Differential movement of sand grains in the nearshore environment; a study using fluorescent tracers. (Abstract only.) B')lm. parana. GeoscL, 33: p. 32. Fluorescent tracers were used in several tests with the purpose of analysing the sorting of various sand size fractions in a relatively high-energy environment. Large amounts of ,:oloured sand (varying from 30 to 64 Kg) were released and core samples were collected at different intervals in a radial pattern around the source point using plastic tubes (height: 7 cm; diameter: 3 cm). Each core sample (about 2 cm height) was separated into several size fractions by screening and the number of fluorescent grains was determined by analysing each fraction with a U.V. lamp. Wave heights and periods, and longshore currents were measured during each tracer test. The analysis of tracer data indicate thai the average grain velocities differ for the various size fractions; the coarser grains exhibit lower velocities than the finer ones. So far, the results show a similar directional pattern for all grain sizes over short intervals (one hour or less). JEFFREY S.W., 1976. The occurrence of chlorophyll c i and c2 in algae. ,L Phycol., 12 (3): 349-354. Forty-two species of chlorophyll c- containing algae (diatoms, dinofagellates, chrysomonads, haptophytes, cryptomonads, and xanthophytes) were examined for their content of chlorophyll c~ and c2. This work, and recent studies on c~/c2 distribution in the literature (total 86 species), show that chlorophyll c2 is universal to all algae examined. Chlorophyll Cl occurs in addition to c2 in brown seaweeds, diatoms, chrysomonads, haptophytes (coccolithophorids), xanthophytes, and the fucoxanthin-containing dinoflagellates; c2 only occurs in dinoflagellales and cryptomonads. Two exceptions to the generalizations are one dinoflagellate and one cryptomonad containing e~ in addition to e , . No explanation can be offered on present knowledge for these exceptions. No alga was found containing only chlorophyll c~. Chlorophyll c, far from being a minor accessory chlorophyll, occurred in amounts almost equal to chlorophyll a (some diatoms and dinoflagellates) or ranged from 50 to 20% of the chlorophyll a (diatoms, dinoflagellates, chrysomonads, cryptomonads, browns). Xanthophytes, however, contained only trace amounts of chlorophyll c, with ratios of chlorophyll a : c ranging from 55 : 1 to 116 : 1 on a weight basis. In those algae with both chlorophyll c components, c~ and c2 occurred either in equal amounts, or chlorophyll c2 was twice the c~ content. JEFFREY S. W., 1976. A report of green algal pigments in the central North Pacific Ocean. Mar. Biol., 37 (I):
33-37.
Thin-layer chromatography showed that chlorophyll b was present in acetone extracts of 6 samples of suspended matter collected in February 1973 from the central North Pacific Ocean. Pigment patterns showed the presence of green algae and diatoms through most of the euphotic zone down to 200 m. Ratios of chlorophyll b :a ranged from 0.2 to 0.5 at 5 and 100 m depths, but were less than 0.05 at 200 m. JOHNS B., 1976. A note on the boundary layer at the floor of a tidal channel. Dynam. Atmos. Oceans, I (1): 91-98. A numerical model is used to study the effecl of non-linearities on the dynamics of the boundary layer at the floor of a tidal channel. A feature of the model is the use of a non-linear transfer term to represent the effect of the turbulent stress in the system. Numerical evaluations are made in order to determine whether this term leads to distortions in the current profiles that are comparable with those normally associated with the inertia terms. Comparisons are also made between the predicted current profiles and those obtained from a simple Stokes' "shear-wave" solution. JOHNSON W. S., 1976. Biology and population dynamics of the intertidal isopod Cirolana harfordi. 343-350.
Mar. Biol.. 3~; (4):
The distribution of Cirolana harlbrdi (Lockington) populations is determined largely by the availability of loose boulders on sandy beaches. The isopods swim out from under the rocks at high tide to feed. Their diet consists primarily of minute polychaetes and crustaceans. In addition, the isopods locate and utilize any available dead animal matter in the surf zone. Breeding occurs throughout most of the year, except for a brief lull in the fall. Females produce I or 2 broods of 18 to 68 young during their 2-year lifespan. Marsupial incubation lasts 3 to 4 months. The population size and structure remained relatively constant from one year to the next. Mortality rates estimated for juveniles, males and females showed that newly emergent young and post-reproductive females suffer the greatest losses (up to 75% mortality per month).
Oceanographic Abstracts
HOBSON L.A., W.J. MORRIS and K. T. P1RQUET, 1976. Theoretical and experimental analysis of the J4C technique and its use in studies of primary production. J. Fish. Res. Board Can., 33 (8): 1715-1721. Theoretical and experimental field studies of ~4C uptake by marine phytoplankton were carried out to determine environmental conditions required for the technique to measure net photosynthesis. Results of theoretical studies indicate that rapidly metabolizing populations (rate constants for gross photosynthesis and respiration of 0.1 h -~ and 0.007 h -~, respectively) may saturate with ~4C after about 30 h of continuous irradiation, Results of field studies indicate that a minimum of 24 h are required for net photosynthesis to be measured when daily irradiations exceed 20 cat cm -2 and nutrient limitation of photosynthesis does not occur. Additional measurements that may be made to aid in interpreting results obtained by the ~4C technique are briefly discussed. HOLLIBAUGH J. T., 1976. The biological degradation of arginine and glutamic acid in seawater in relation to the growth of phytoplankton. Mar. Biol., 36 (4): 303-312. The responses of natural summer coastal plankton communities to low-level additions (10-s to 10 -7 M) of arginine and glutamic acid has been followed by in vivo measurement of chlorophyll fluorescence. This technique is capable of detecting a response to a 10-6 M enrichment under most conditions. The time sequence of the response varied with the amino acid used and with the enantiomeric form of the amino acid. Ammonia and carbon dioxide were liberated before the increase in chlorophyll fluorescence occurred. Liberation of ammonia in a dark bottle from L-arginine was from 75 to 85% of the theoretical yield. Microautoradiography using 14C L-arginine or L-glutamic acid at 10-7 M showed heavy labeling associated with fecal pellets and detrital aggregates. Phytoplankton cells were not appreciably labeled. The evidence suggests that bacteria are important in the cycling of these compounds. HOPPE H.-G., 1976. Determination and properties of actively metabolizing heterotrophic bacteria in the sea, investigated by means of microautoradiography. Mar. Biol., 36 (4): 291-302. Substrate transformation and microbial biomass production in aquatic ecosystems depend mainly on the total number of actively metabolizing heterotrophic bacteria. The most common methods used concern the determination of either the colony-forming bacteria or the total number of bacteria including autotrophs and inactive organisms. A micro-autoradiographic method is presented which enables the substrate uptake of single bacteria by means of 3H-amino-acid mixture and Nuclepore filters to be determined. The standardization procedure rew,'aled the greatest success after 3 h incubation with 10/aCi/ml tritiated amino-acid mixture and an exposure of 14 days to the X-r,'ty film. Preliminary experiments showed inactivation of an active fresh-water population from 100% to 0.6% within 3 h at 28 °/70 S. With increasing distance from the shore, the number of colony-forming units decreases from 6 to 0.01% of the total numger of active heterotrophic bacteria. It is concluded from the results that the fraction of very small heterotrophic bacteria which cannot be cultured on nutrient media is responsible for the continuous breakdown of organic matter in offshore regions of the s~a. HORNIBROOK N. de B., 1976. Globorotalia truncatulinoides and the Pliocene-Pleistoeene boundary in northem Hawkes Bay New Zealand. Progress in micropaleontology, 83-102. Micropaleontology Press, N. Y. A 1,000-fuot (300-m) drill hole in thick, rapidly deposited, marine Pliocene-Pleistocene beds at Wairoa, to investigate the zone of overlap of Globorotalia tosaensis and G. truncatulinoides provided a detailed sequence containing both forms, through the upper 850 feet (260 m ) of pumiceous siltstone but did not penetrate the total interval of overlap. The ratio of keeled to non-keeled forms is variable, although the non-keeled form becomes more predominant with increasing depth. The two forms appear to be morphotopical extremes of a single species. Populations between 249 feet (75 m ) and 552 feet (170 m ) consist of sparse, small, sinistrally coiled individuals, whereas above and below this interval they are more abundant, larger, and dextrally coiled. The earliest specimens of G. tosaensis occur within the upper part of the range-zone of Obicides molestus (Waipipian Stage, Late Pliocene) but not earlier. There is a close match of bolh foraminifera and calcareous nannofosslls with the relatively thick overlap zone of G. tosaensis and G. truneatulinoides in DSDP S te 206 in the New Caledonia Basin. The last discoasters occur well above the earliest G. truncatulinoides in both localities, and there is an interval of more than 2,000 feet (600 m ) in the Wairoa Syncline within which the Plio-Pleistocene boundary could be placed. Correlation with the Calabrian is uncertain. The ranges of Globorotalia cr~ssula and G. crassafi~rmis are useful locally. Globorotalia crassaformis coils dextrally below 692 feet and sinistrally above that level. Changes in faunal diversity ar d in coiling direction of Globorotalia pachyderrna and G. truncatulinoides indicate alternations of warm and cool periods. INGENITO FRANK and S. N. WOLF, 1976. Acoustic propagation in shallow water overlying a consolidated bottom. J. acoust. S~c. Am., 60 (3): 611-617. An experiment designed to measure normal mode amplitude functions and attenuation coefficients was conducted in shallow water on Campeche Bank off the Yucatar Peninsula. Measurements were made at two locations on the bank in water of about 30 m in depth over a bottom consisting of consolidated limestone having a measured and sound velocity of 1,900 m/sec. Pulsed cw signals
Oceanographic Abstracts
201
with frequencies of 400, 750, and 1,500 Hz were used. Theoretical calculations of the mode amplitude functions using a fluid model of the bottom were found to agree well with the measurements. In order to reconcile the measured mode attenuation coefficients with theory, it was necessary to assume that the shear velocity of the bottom was 1,000 m/sec. The latter is lower than the minimum sound velocity in the water column so that the generation of propagating shear waves in the bottom was the dominant attenuation mechanism. Significant differences in the measured mode attenuation coefficients at the two stations were explained by the deepening of the low velocity channel at the bottom of the water column. INGLE J. C. Jr. and E. J. SCHNACK, 1975. Differential movement of sand grains in the nearshore environment; a study using fluorescent tracers. (Abstract only.) B')lm. parana. GeoscL, 33: p. 32. Fluorescent tracers were used in several tests with the purpose of analysing the sorting of various sand size fractions in a relatively high-energy environment. Large amounts of ,:oloured sand (varying from 30 to 64 Kg) were released and core samples were collected at different intervals in a radial pattern around the source point using plastic tubes (height: 7 cm; diameter: 3 cm). Each core sample (about 2 cm height) was separated into several size fractions by screening and the number of fluorescent grains was determined by analysing each fraction with a U.V. lamp. Wave heights and periods, and longshore currents were measured during each tracer test. The analysis of tracer data indicate thai the average grain velocities differ for the various size fractions; the coarser grains exhibit lower velocities than the finer ones. So far, the results show a similar directional pattern for all grain sizes over short intervals (one hour or less). JEFFREY S.W., 1976. The occurrence of chlorophyll c i and c2 in algae. ,L Phycol., 12 (3): 349-354. Forty-two species of chlorophyll c- containing algae (diatoms, dinofagellates, chrysomonads, haptophytes, cryptomonads, and xanthophytes) were examined for their content of chlorophyll c~ and c2. This work, and recent studies on c~/c2 distribution in the literature (total 86 species), show that chlorophyll c2 is universal to all algae examined. Chlorophyll Cl occurs in addition to c2 in brown seaweeds, diatoms, chrysomonads, haptophytes (coccolithophorids), xanthophytes, and the fucoxanthin-containing dinoflagellates; c2 only occurs in dinoflagellales and cryptomonads. Two exceptions to the generalizations are one dinoflagellate and one cryptomonad containing e~ in addition to e , . No explanation can be offered on present knowledge for these exceptions. No alga was found containing only chlorophyll c~. Chlorophyll c, far from being a minor accessory chlorophyll, occurred in amounts almost equal to chlorophyll a (some diatoms and dinoflagellates) or ranged from 50 to 20% of the chlorophyll a (diatoms, dinoflagellates, chrysomonads, cryptomonads, browns). Xanthophytes, however, contained only trace amounts of chlorophyll c, with ratios of chlorophyll a : c ranging from 55 : 1 to 116 : 1 on a weight basis. In those algae with both chlorophyll c components, c~ and c2 occurred either in equal amounts, or chlorophyll c2 was twice the c~ content. JEFFREY S. W., 1976. A report of green algal pigments in the central North Pacific Ocean. Mar. Biol., 37 (I):
33-37.
Thin-layer chromatography showed that chlorophyll b was present in acetone extracts of 6 samples of suspended matter collected in February 1973 from the central North Pacific Ocean. Pigment patterns showed the presence of green algae and diatoms through most of the euphotic zone down to 200 m. Ratios of chlorophyll b :a ranged from 0.2 to 0.5 at 5 and 100 m depths, but were less than 0.05 at 200 m. JOHNS B., 1976. A note on the boundary layer at the floor of a tidal channel. Dynam. Atmos. Oceans, I (1): 91-98. A numerical model is used to study the effecl of non-linearities on the dynamics of the boundary layer at the floor of a tidal channel. A feature of the model is the use of a non-linear transfer term to represent the effect of the turbulent stress in the system. Numerical evaluations are made in order to determine whether this term leads to distortions in the current profiles that are comparable with those normally associated with the inertia terms. Comparisons are also made between the predicted current profiles and those obtained from a simple Stokes' "shear-wave" solution. JOHNSON W. S., 1976. Biology and population dynamics of the intertidal isopod Cirolana harfordi. 343-350.
Mar. Biol.. 3~; (4):
The distribution of Cirolana harlbrdi (Lockington) populations is determined largely by the availability of loose boulders on sandy beaches. The isopods swim out from under the rocks at high tide to feed. Their diet consists primarily of minute polychaetes and crustaceans. In addition, the isopods locate and utilize any available dead animal matter in the surf zone. Breeding occurs throughout most of the year, except for a brief lull in the fall. Females produce I or 2 broods of 18 to 68 young during their 2-year lifespan. Marsupial incubation lasts 3 to 4 months. The population size and structure remained relatively constant from one year to the next. Mortality rates estimated for juveniles, males and females showed that newly emergent young and post-reproductive females suffer the greatest losses (up to 75% mortality per month).