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Delayed recruitment models and their application to the American lobster (Homarus americanus) fishery
206
Oceanographic Abstracts
by dextrally coiled populations in the early Pleistocene. Since the sinistral populations of G. pachyderma are known to occur in high northern latitudes in water masses whose April surface temperatures do not exceed 7.2°C, the sudden appearance of the sinistrally coiled G. pachyderma at about 1.2 m y B.P. is taken as an indicator of a considerable temperature decline in the North Pacific at that time possibly coincident with the initiation of mid-latitude glaciations of Europe and North America. The eustatic lowering of sea level exposed the shallow Korea Strait aS a land bridge and terminated the flow of warm Pacific waters into the Sea of Japan. The curtailment of warm Pacific waters substantially lowered water temperatures of the Sea of Japan, thus bringing the left-coiling populations of G. pachyderma into the areas formerly inhabited by the right-coiling populations. MARCHESSEAULT G.D., S. B. SAILA and W. J. PALM. I976. Delayed recruitment models and their application to the American lobster ( Homarus amencanus ) fishery. J. Fish. Res. Board Can., 33 (8): 1779-1787. A delayed recruitment model intended for use in developing dynamic strategies for fisheries management is proposed. The conceptual and analytical properties of the model are elaborated and compared with those of the instantaneous model of Schaefer and the delayed recruitment model recently suggested by Walter. Of the three models discussed, the delayed recruitment model proposed herein constitutes the more biologically meaningful tool for use in management decision making with fisheries characterized by a multiple year delay between spawning and recruitment. The proposed delay and Schaefer models are fitted to catch and effort data from the Rhode Island inshore pot lobster fishery, and the generated coefficients are examined with respect to their interpretation and relative importance. Values of optimum equilibrium catch and effort are calculated for the proposed delay and Schaefer models, and we show that the delay modeFs estimates of these management indices are more conservative than those derived from Schaefer's model, q'he proposed delay and Schaefer models are compared in a dynamic analysis of the fishery, in which perturbations in the stock level and fluctuations in the applied effort are simulated to predict the subsequent behavior of the stock. MARCHUK G. I. and Yu. N. SKIBA, 1976. Numerical calculation of the conjugate problem for the model of thermal interaction of the atmosphere, oceans and continents. (In Russian; English abstract.) Fiz. Atrnosf. Okeana. Izv. Akad. Nauk, SSSR, 12 (5): 459-469. The model of thermal interaction of the Earth's atmosphere, the World Ocean and continents is investigated for long-range weather prediction. Here we employ the approach based on the use of the solution of specifically stated conjugate problems. The conjugate solution is connected with the function of the temperature anomaly being predicted. The conjugate solution serves as the basic criterion of significance of input data with respect to this function. A balanced absolutely stable difference scheme is constructed for numerical calculation of the problem. The splitting-up method being employed allows us to construct an efficient computing algorithm. Results of the numerical experiments are analyzed. MATOBA YASUMOCHI, 1976. Foraminifera from off Noshiro, Japan, and postmortem destruction of tests in the Japan Sea. Progress in micropaleontology, 169-189. Micropaleontology Press, N.Y. The Recent foraminiferal fauna from off Noshiro, Japan Sea, was studied in 18 samples of bottom sediments from the continental shelf and slope. Three major fauras were found, corresponding to three types of water masses, and the water maSs seems to be most important for the faunal dis|ribution. The shelf fauna, including the subtropical neritic species, is related to the warm Tsushima Current. The transitional fauna, the Reophax-Trochammina assemblage, is at the uppermost part of the slope under the Lower Thermocline. The slope fauna, the 7halmannammina parkerae-Trochammina japonica assemblage, is under the Japan Sea Proper Water of low temperature, rather low salinity, and high content of dissolved oxygen, and includes many characteristic species. The postmortem dissolution is noted fiom comparisons among living, total, calcareous, and agglutinated populations. It is seen in two areas: one in the central part of the shelf influenced by water from land; the other on the continental slope under the water of the Lower Thermocline and the Japan Sea Proper Water. MAYZAUD P., 1976. Respiration and nitrogen excretion of zooplankton. IV. The influence of starvation on the metabolism and the biochemical composirion of some species. Mar. BioL, 37 (1): 47-58. Changes in the respiration, ammonia excretion and biochemical composition were studied for three species of starving zooplankton
(Calanus finmarchicus, Sagitta elegans, and Acartia clausi). Over the period of starvation, the respiration rate of all three species followed the same pattern of an initial decrease followed by a more or less constant level. A similar pattern was observed for the ammonia excretion rate ofS. elegans and A. clausi, whereas C. finmarchicus excretion appeared to oscillate between high and low levels of protein catabolism. Study of the biochemical changes showed that C. finmarchicus consumed primarily lipids, and at times proteins, to meet its energy requirement whereaS S. elegans and A. clausi primarily used protein. Variations in the elemental composition aS well aS the O:N ratio confirmed that C. finmarchicus alternated between periods of protein-dominant catabolism and lipid-dominant catabolism during starvation. No similar change in catabolism was observed in the two other species. The results are discussed in terms of physiological mechanisms of resistance to starvation and were used to calculate the energy budget of S. elegans and C. finmarchicus during the period of total starvation. The significance of such budgets is discussed and some of the sources of error examined.
Oceanographic Abstracts
by dextrally coiled populations in the early Pleistocene. Since the sinistral populations of G. pachyderma are known to occur in high northern latitudes in water masses whose April surface temperatures do not exceed 7.2°C, the sudden appearance of the sinistrally coiled G. pachyderma at about 1.2 m y B.P. is taken as an indicator of a considerable temperature decline in the North Pacific at that time possibly coincident with the initiation of mid-latitude glaciations of Europe and North America. The eustatic lowering of sea level exposed the shallow Korea Strait aS a land bridge and terminated the flow of warm Pacific waters into the Sea of Japan. The curtailment of warm Pacific waters substantially lowered water temperatures of the Sea of Japan, thus bringing the left-coiling populations of G. pachyderma into the areas formerly inhabited by the right-coiling populations. MARCHESSEAULT G.D., S. B. SAILA and W. J. PALM. I976. Delayed recruitment models and their application to the American lobster ( Homarus amencanus ) fishery. J. Fish. Res. Board Can., 33 (8): 1779-1787. A delayed recruitment model intended for use in developing dynamic strategies for fisheries management is proposed. The conceptual and analytical properties of the model are elaborated and compared with those of the instantaneous model of Schaefer and the delayed recruitment model recently suggested by Walter. Of the three models discussed, the delayed recruitment model proposed herein constitutes the more biologically meaningful tool for use in management decision making with fisheries characterized by a multiple year delay between spawning and recruitment. The proposed delay and Schaefer models are fitted to catch and effort data from the Rhode Island inshore pot lobster fishery, and the generated coefficients are examined with respect to their interpretation and relative importance. Values of optimum equilibrium catch and effort are calculated for the proposed delay and Schaefer models, and we show that the delay modeFs estimates of these management indices are more conservative than those derived from Schaefer's model, q'he proposed delay and Schaefer models are compared in a dynamic analysis of the fishery, in which perturbations in the stock level and fluctuations in the applied effort are simulated to predict the subsequent behavior of the stock. MARCHUK G. I. and Yu. N. SKIBA, 1976. Numerical calculation of the conjugate problem for the model of thermal interaction of the atmosphere, oceans and continents. (In Russian; English abstract.) Fiz. Atrnosf. Okeana. Izv. Akad. Nauk, SSSR, 12 (5): 459-469. The model of thermal interaction of the Earth's atmosphere, the World Ocean and continents is investigated for long-range weather prediction. Here we employ the approach based on the use of the solution of specifically stated conjugate problems. The conjugate solution is connected with the function of the temperature anomaly being predicted. The conjugate solution serves as the basic criterion of significance of input data with respect to this function. A balanced absolutely stable difference scheme is constructed for numerical calculation of the problem. The splitting-up method being employed allows us to construct an efficient computing algorithm. Results of the numerical experiments are analyzed. MATOBA YASUMOCHI, 1976. Foraminifera from off Noshiro, Japan, and postmortem destruction of tests in the Japan Sea. Progress in micropaleontology, 169-189. Micropaleontology Press, N.Y. The Recent foraminiferal fauna from off Noshiro, Japan Sea, was studied in 18 samples of bottom sediments from the continental shelf and slope. Three major fauras were found, corresponding to three types of water masses, and the water maSs seems to be most important for the faunal dis|ribution. The shelf fauna, including the subtropical neritic species, is related to the warm Tsushima Current. The transitional fauna, the Reophax-Trochammina assemblage, is at the uppermost part of the slope under the Lower Thermocline. The slope fauna, the 7halmannammina parkerae-Trochammina japonica assemblage, is under the Japan Sea Proper Water of low temperature, rather low salinity, and high content of dissolved oxygen, and includes many characteristic species. The postmortem dissolution is noted fiom comparisons among living, total, calcareous, and agglutinated populations. It is seen in two areas: one in the central part of the shelf influenced by water from land; the other on the continental slope under the water of the Lower Thermocline and the Japan Sea Proper Water. MAYZAUD P., 1976. Respiration and nitrogen excretion of zooplankton. IV. The influence of starvation on the metabolism and the biochemical composirion of some species. Mar. BioL, 37 (1): 47-58. Changes in the respiration, ammonia excretion and biochemical composition were studied for three species of starving zooplankton
(Calanus finmarchicus, Sagitta elegans, and Acartia clausi). Over the period of starvation, the respiration rate of all three species followed the same pattern of an initial decrease followed by a more or less constant level. A similar pattern was observed for the ammonia excretion rate ofS. elegans and A. clausi, whereas C. finmarchicus excretion appeared to oscillate between high and low levels of protein catabolism. Study of the biochemical changes showed that C. finmarchicus consumed primarily lipids, and at times proteins, to meet its energy requirement whereaS S. elegans and A. clausi primarily used protein. Variations in the elemental composition aS well aS the O:N ratio confirmed that C. finmarchicus alternated between periods of protein-dominant catabolism and lipid-dominant catabolism during starvation. No similar change in catabolism was observed in the two other species. The results are discussed in terms of physiological mechanisms of resistance to starvation and were used to calculate the energy budget of S. elegans and C. finmarchicus during the period of total starvation. The significance of such budgets is discussed and some of the sources of error examined.