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1024 Oceanographic Abstracts ANGOT MICHEL, 1965. Cycle annual de l'hydrologie dans la rrgion proche de Nosy-Bg. Cahiers, O.R.S.T.O.M. Ocdanogr., 3 (1): 55-66. L'&ude ci-dessus fait apparaitre les rapports tr/~s 6troits qui existent entre l'hydrologie superficielle et subsuperficielle de la zone maritime proche de Nosy-B6 et les caractrristiques climatologiques de cette m~me rrgion. En fait, des rapports aussi 6troits ne doivent pas nous surprendre, et ce pour deux raisons principales, l'une d'origine mrtrorologique, l'autre d'origine grographique. Nosy-B6 poss~de un climat essentiellement tropical. La temprrature moyenne annuelle de l'air varie dans de tr~s 6troites limites (24° 1-27 ° 3) alors clue la quantit6 de pluie subit de considrrables fluc- tuations (55 mm en septembre et 625 mm en janvier). Dans ces conditions, il est normal que les caractgristiques hydrologiques soient considerablement affectb.es par la seule variable v6ritable, ~t savoir la pluie. Le minimum de temp6rature de janvier par exemple (ou frvrier, selon les stations) n'est que le rrsultat indirect de l'abondance subite des chutes de pluie dont la premirre action est de provoquer la baisse de la temprrature de rair en dgcembre. Sur le plan g6ographique, Nosy-B6 se trouve h proximit6 des drbouchrs de trois grandes rivi~res dont les drbits varient en fonction directe de l'abondance des pluies. De plus, jusqu'h l'isobathe de 100 m~tres, la profondeur de ce qu'on a appel6 plateau continental est suffisamment faible pour que la masse d'eau qui la surmonte soit sensible aux fluctuations de la couche superficielle. Pour conclure, on peut donc dire que l'rtude ci-dessus est celle d'un milieu maritime crtier aux caract~res typiquement tropicaux o/~ le facteur principal d'6volution saisonni~re est la quantit6 de pluie tombre dans les semaines qui prrc&lent les observations. Les variations provoqures sont souvent considgrables pour un milieu tropical dont les caract6ristiques, /t l'oppos6 de celles d'un milieu plus froid, ne s'rcartent que 16g~rement de leur position d'b..quilibre. De telles fluctuations ont certainement une trrs grande influence sur les populations biologiques qui habitent les masses d'eau en cause. ANTIA N. J., and A. WATT, 1965. Phosphatase activity in some species of marine phytoplankters. J. Fish. Res. Bd., Canada, 22 (3): 793-799. Evidence has been obtained for acid phosphatase activity (on p-nitrophenyl phosphate as substrate) at pH 4.8 in cell-free extracts of Phaeodactylum tricornutum, Skeletonema costatum, Cyclotella nana, Monochrysis lutheri, lsochrysis galbana, and Dunaliella tertiolecta grown photoautotrophically in pure culture. No alkaline phosphatase activity at pH 10.5 was observed. ANTONOV A. E. and O. S. ROUDNEVA, 1965. Peculiarities of hydrological and hydrochemical conditions in the south Baltic during the IGY. (In Russian; English Abstract). Okeanolog. Issled. Rezult. Issled. Programme. Mezhd. Geofiz. Goda. Mezhd. Geofiz. Komitet. Presidiume. Akad. Nauk. SSSR. No. 13: 90-95. The IGY took place during the end of a freshening cycle in the Baltic Sea 0957-1958) and the be- ginning of a new salinity cycle (1959). In 1958 i.e. during the period of the maximum stagnation of pre-bottom waters of the Southern Baltic there was a minimal salinity for the last 60 years period very low temperatures and low dissolved oxygen content. Phosphates and silicates were high. The salinity and temperature of the total water column were the lowest in 15 years. In 1959 there was a complete renewal of the pre-bottom layers of the Southern Baltic, which was followed by a sharp increase in salinity temperatures, and dissolved oxygen and a decrease in nutrients. These processes occurred as a result of the inflow of saline waters. The tentative forecast for the pre-bottom salinity due the river discharge for the average year days in the meridional, western and eastern circulation, which was compiled in 1960 proved to be 80 ~ correct. In the next five years western circulation will be heightened, there will be less ice and also some increase of salinity of the pre-bottom waters of the Southern Baltic. APPLEGATE VERNON C. and M. L. H. THOMAS, 1965. Sex ratios and sexual dimorphism among recently transformed sea lampreys, Petromyzon marinus Linnaeus. J. Fish. Res. Bd., Canada, 22 (3): 695-711. The sex, length, and weight were determined of nearly all recently transformed sea lampreys mi- grating downstream in the Carp Lake River, Michigan, in the fall, winter, and spring of 1960-61. Similar data were collected from samples of an earlier run in the Carp Lake River and of runs in three other tributaries of Lakes Huron and Michigan. The sex ratio of the 1960-61 migrants in the Carp Lake River was 324 males : 100 females. Sex ratios of migrants in the other runs varied from 77 to 86 males : 100 females. The high proportion of males in the 1960-61 run in the Carp Lake River is attributed to the effective prevention of recruitment of sea lampreys in the river and transformation of the females at an earlier age than is characteristic of the males. A near equal sex ratio among recently transformed migrants is considered normal for the species. The sex com- position of a run changed during the period of migration. The proportion of males among the mi- grants was greatest at the beginning of the run and declined steadily thereafter. The average size was smaller for males than for females. Differences in the mean lengths and weights of the sexes were statistically significant. The length-weight relation differed for the sexes and showed a slower rate of increase of weight with increase in length than is characteristic of other stages of the animals' life cycle. Seasonal changes in the length-weight relation had a trend towards lower weights among the migrants coming downstream in the later months of the run.

Phosphatase activity in some species of marine phytoplankters : Antia N. J., and A. Watt, 1965. J. Fish. Res. Bd., Canada, 22 (3): 793–799

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Page 1: Phosphatase activity in some species of marine phytoplankters : Antia N. J., and A. Watt, 1965. J. Fish. Res. Bd., Canada, 22 (3): 793–799

1024 Oceanographic Abstracts

ANGOT MICHEL, 1965. Cycle annual de l'hydrologie dans la rrgion proche de Nosy-Bg. Cahiers, O.R.S.T.O.M. Ocdanogr., 3 (1): 55-66. L'&ude ci-dessus fait apparaitre les rapports tr/~s 6troits qui existent entre l 'hydrologie superficielle et subsuperficielle de la zone maritime proche de Nosy-B6 et les caractrristiques climatologiques de cette m~me rrgion. En fait, des rapports aussi 6troits ne doivent pas nous surprendre, et ce pour deux raisons principales, l 'une d'origine mrtrorologique, l 'autre d'origine grographique.

Nosy-B6 poss~de un climat essentiellement tropical. La temprrature moyenne annuelle de l 'air varie dans de tr~s 6troites limites (24 ° 1-27 ° 3) alors clue la quantit6 de pluie subit de considrrables fluc- tuations (55 mm en septembre et 625 mm en janvier). Dans ces conditions, il est normal que les caractgristiques hydrologiques soient considerablement affectb.es par la seule variable v6ritable, ~t savoir la pluie. Le minimum de temp6rature de janvier par exemple (ou frvrier, selon les stations) n'est que le rrsultat indirect de l 'abondance subite des chutes de pluie dont la premirre action est de provoquer la baisse de la temprrature de ra i r en dgcembre.

Sur le plan g6ographique, Nosy-B6 se trouve h proximit6 des drbouchrs de trois grandes rivi~res dont les drbits varient en fonction directe de l 'abondance des pluies. De plus, jusqu'h l ' isobathe de 100 m~tres, la profondeur de ce qu 'on a appel6 plateau continental est suffisamment faible pour que la masse d'eau qui la surmonte soit sensible aux fluctuations de la couche superficielle.

Pour conclure, on peut donc dire que l 'rtude ci-dessus est celle d 'un milieu maritime crt ier aux caract~res typiquement tropicaux o/~ le facteur principal d'6volution saisonni~re est la quantit6 de pluie tombre dans les semaines qui prrc&lent les observations. Les variations provoqures sont souvent considgrables pour un milieu tropical dont les caract6ristiques, /t l 'oppos6 de celles d 'un milieu plus froid, ne s 'rcartent que 16g~rement de leur position d'b..quilibre. De telles fluctuations ont certainement une trrs grande influence sur les populations biologiques qui habitent les masses d'eau en cause.

ANTIA N. J., and A. WATT, 1965. Phosphatase activity in some species of marine phytoplankters. J. Fish. Res. Bd., Canada, 22 (3): 793-799. Evidence has been obtained for acid phosphatase activity (on p-nitrophenyl phosphate as substrate) at pH 4.8 in cell-free extracts of Phaeodactylum tricornutum, Skeletonema costatum, Cyclotella nana, Monochrysis lutheri, lsochrysis galbana, and Dunaliella tertiolecta grown photoautotrophically in pure culture. No alkaline phosphatase activity at pH 10.5 was observed.

ANTONOV A. E. and O. S. ROUDNEVA, 1965. Peculiarities of hydrological and hydrochemical conditions in the south Baltic during the IGY. (In Russian; English Abstract). Okeanolog. Issled. Rezult. Issled. Programme. Mezhd. Geofiz. Goda. Mezhd. Geofiz. Komitet. Presidiume. Akad. Nauk. SSSR. No. 13: 90-95. The IGY took place during the end of a freshening cycle in the Baltic Sea 0957-1958) and the be- ginning of a new salinity cycle (1959). In 1958 i.e. during the period of the maximum stagnation of pre-bottom waters of the Southern Baltic there was a minimal salinity for the last 60 years period very low temperatures and low dissolved oxygen content. Phosphates and silicates were high. The salinity and temperature of the total water column were the lowest in 15 years. In 1959 there was a complete renewal of the pre-bottom layers of the Southern Baltic, which was followed by a sharp increase in salinity temperatures, and dissolved oxygen and a decrease in nutrients. These processes occurred as a result of the inflow of saline waters. The tentative forecast for the pre-bottom salinity due the river discharge for the average year days in the meridional, western and eastern circulation, which was compiled in 1960 proved to be 80 ~ correct. In the next five years western circulation will be heightened, there will be less ice and also some increase of salinity of the pre-bottom waters of the Southern Baltic.

APPLEGATE VERNON C. and M. L. H. THOMAS, 1965. Sex ratios and sexual dimorphism among recently transformed sea lampreys, Petromyzon marinus Linnaeus. J. Fish. Res. Bd., Canada, 22 (3): 695-711. The sex, length, and weight were determined of nearly all recently transformed sea lampreys mi- grating downstream in the Carp Lake River, Michigan, in the fall, winter, and spring of 1960-61. Similar data were collected from samples of an earlier run in the Carp Lake River and of runs in three other tributaries of Lakes Huron and Michigan. The sex ratio of the 1960-61 migrants in the Carp Lake River was 324 males : 100 females. Sex ratios of migrants in the other runs varied from 77 to 86 males : 100 females. The high proportion of males in the 1960-61 run in the Carp Lake River is attributed to the effective prevention of recruitment of sea lampreys in the river and transformation of the females at an earlier age than is characteristic of the males. A near equal sex ratio among recently transformed migrants is considered normal for the species. The sex com- position of a run changed during the period of migration. The proportion of males among the mi- grants was greatest at the beginning of the run and declined steadily thereafter. The average size was smaller for males than for females. Differences in the mean lengths and weights of the sexes were statistically significant. The length-weight relation differed for the sexes and showed a slower rate of increase of weight with increase in length than is characteristic of other stages of the animals' life cycle. Seasonal changes in the length-weight relation had a trend towards lower weights among the migrants coming downstream in the later months of the run.