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Patrick Ouellet - One of the best experts on this subject based on the ideXlab platform.
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ocean surface characteristics influence recruitment variability of populations of northern shrimp Pandalus borealis in the northwest atlantic
Ices Journal of Marine Science, 2011Co-Authors: Patrick Ouellet, Cesar Fuentesyaco, Shubha Sathyendranath, Trevor Platt, P Koeller, Louise Savard, Helle SiegstadAbstract:Remotely sensed data were used to derive simple ecosystem indicators for four regions of the Northwest Atlantic to test the hypothesis that sea surface temperatures (SSTs) and spring phytoplankton bloom characteristics (initiation, timing, intensity, and duration) have a significant influence on larval survival and recruitment of northern shrimp (Pandalus borealis). For all years (1998 – 2007) and regions, hatching was after the initiation of the bloom and before or after the bloom reached its maximum intensity. The results suggest that the best survival of larvae is associated with high warming rates of SST following hatching, but in very cold environments, warm temperatures at hatching seem to be important for larval survival. The analyses also indicate that larval survival is supported by an early, long phytoplankton bloom which attains high concentrations of chlorophyll a. The results demonstrate the potential of remotely sensed data for deriving simple population-specific ecosystem indicators for potential use in building operational recruitment models for predicting changes in northern shrimp abundance.
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Diet Components of Northern Shrimp Pandalus borealis First Stage Larvae in the Northwest Gulf of St. Lawrence
Journal of Crustacean Biology, 2009Co-Authors: Paola Ariza, Patrick OuelletAbstract:Abstract The objective of this study was to clarify the diet composition of the first stage larvae of northern shrimp Pandalus borealis during the spring period of high biological production in the Northwestern Gulf of St. Lawrence (NWGSL). Data collected in spring 2006 revealed that hatching of P. borealis larvae took place in late April and early May during a period characterized by a phytoplankton bloom (mainly species of the genus Chaetoceros) and by an abundance of early stages of mesozooplankton, which demonstrated the onset of secondary production at the sampling site. Gut content examination of stage I larvae sampled at the site and feeding experiments conducted at sea revealed that omnivorous feeding starts at hatching, but a first approximation based on the quantity of pigments present in the larvae suggest that zooplankton is more important than phytoplankton to meet the larvae's energy needs. In addition, field observations of the degree of gut fullness and the low percentage (10%) of larvae w...
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Rearing Pandalus borealis (Krøyer) larvae in the laboratory
Marine Biology, 2005Co-Authors: Patrick Ouellet, Denis ChabotAbstract:Northern shrimp Pandalus borealis (Krøyer) larvae hatch in the northern Gulf of St. Lawrence from early May to the end of June, and larval development occurs over a range of relatively cold water temperatures. Because of the long duration of the pelagic phase and the difficulty of sampling all successive larval stages at sea, we used laboratory experiments to assess the effects of water temperature on larval development and growth. In spring 2000, P. borealis larvae were reared from hatching to the first juvenile stages (i.e., stage VI and VII) at three temperatures (3, 5, and 8°C) representing conditions similar to those in spring in the northern Gulf of St. Lawrence. Larval development and growth were dependent on temperature, with longer duration and smaller size (cephalothorax length, CL, and dry mass, DM) at 3°C relative to the 5 and 8°C treatments. There were no significant differences in the morphological characters of the different stages among treatments, indicating that regular moults occurred at each temperature. The results suggest a negative impact of cold temperatures (lower intra-moult growth rates and smaller size) and, possibly, higher cumulative mortality due to longer development time that could affect the success of cohorts at sea. However, CL and DM for stage III and later larvae were smaller than those of larvae identified at the same developmental stage in field locations. It is possible that the diet offered to larvae in this experiment ( Artemia nauplii , either newly hatched nauplii or live adults, depending on the developmental stage) was not optimal for growth, even though it is known to support successful P. borealis larval development. In the field, there is the possibility that phytoplankton contributes to the larval diet during the first stages and stimulates development of the digestive glands. Furthermore, the nutritional quality of the natural plankton diet (e.g., high protein content, fatty acid composition) might be superior and favourable to higher growth rates even at lower temperatures.
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Vertical distribution of northern shrimp (Pandalus borealis) larvae in the Gulf of St. Lawrence ; implications for trophic interactions and transport
Canadian Journal of Fisheries and Aquatic Sciences, 1994Co-Authors: Patrick Ouellet, Denis LefaivreAbstract:In the northwestern Gulf of St. Lawrence in spring 1987 and 1988, stage I and II northern shrimp (Pandalus borealis) larvae were concentrated in the upper (
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lipid condition and survival in shrimp Pandalus borealis larvae
Canadian Journal of Fisheries and Aquatic Sciences, 1992Co-Authors: Patrick Ouellet, Christopher T Taggart, Kenneth T FrankAbstract:Ouellet, P., C. T. Taggart, and K. T. Frank. .l 992. Lipid condition and survival in shrimp (Pandalus borealis) larvae. Can. l. Fish. Aquat. Sci. 49: 368-378. Croups of shrimp (Pandalus borealis) larvae were reared under different food concentrations and types to assess changes in condition and survival during development. As expected, rate of growth (wet weight) was highei for larvae fed on 300 Artemia nauplii.L r (San Francisco strain: 0.0528 mg'd '; Canada strain: 0.0355 mg'd ') compared with those reared at 150 nauplii'L ' (San Francisco strain: 0.0211 mg'd '), larvaefed /sochrysis cells only, and no food. Shrimp larvae reared without food and larvae fed on /sochrysis cells showed a decreasing trend in wet weight during development and did not survive beyond stage ll. The triacylglycerol (TAC) content of larvae accumulated rapidly during the initial phase of intermoult followed by a decline to a minimum coincident with ecdysis. High mortality (average 2.2'/.'d ') occurred during the first phases of development (first 25 d) for all rations. Differences among experiments in the magnitude of the mortality (from 0.86 to 4.66%'d r) at the first moult were related to the proportion of larvae in poor TAC condition. The results are consistent with the concept that the TAC condition index can be used to forecast, on a relative basis, differential survival among larval groups.
Trevor Platt - One of the best experts on this subject based on the ideXlab platform.
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ocean surface characteristics influence recruitment variability of populations of northern shrimp Pandalus borealis in the northwest atlantic
Ices Journal of Marine Science, 2011Co-Authors: Patrick Ouellet, Cesar Fuentesyaco, Shubha Sathyendranath, Trevor Platt, P Koeller, Louise Savard, Helle SiegstadAbstract:Remotely sensed data were used to derive simple ecosystem indicators for four regions of the Northwest Atlantic to test the hypothesis that sea surface temperatures (SSTs) and spring phytoplankton bloom characteristics (initiation, timing, intensity, and duration) have a significant influence on larval survival and recruitment of northern shrimp (Pandalus borealis). For all years (1998 – 2007) and regions, hatching was after the initiation of the bloom and before or after the bloom reached its maximum intensity. The results suggest that the best survival of larvae is associated with high warming rates of SST following hatching, but in very cold environments, warm temperatures at hatching seem to be important for larval survival. The analyses also indicate that larval survival is supported by an early, long phytoplankton bloom which attains high concentrations of chlorophyll a. The results demonstrate the potential of remotely sensed data for deriving simple population-specific ecosystem indicators for potential use in building operational recruitment models for predicting changes in northern shrimp abundance.
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shrimp Pandalus borealis growth and timing of the spring phytoplankton bloom on the newfoundland labrador shelf
Fisheries Oceanography, 2007Co-Authors: Cesar Fuentesyaco, P Koeller, Shubha Sathyendranath, Trevor PlattAbstract:We examined latitudinal and temporal changes in the availability of food for young shrimp (Pandalus borealis) on the Newfoundland–Labrador Shelf, using a suite of quantitative characteristics of the spring phytoplankton bloom determined from satellite ocean colour data, including bloom initiation time, maximum chlorophyll concentration, timing of the maximum, and bloom duration. We found significant correlations between bloom intensity, timing, and the size of young shrimp. The results are discussed in relation to the observation that, since the early 1990s, carapace lengths of shrimp have been decreasing in many Northwest Atlantic stocks.
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Shrimp (Pandalus borealis) growth and timing of the spring phytoplankton bloom on the Newfoundland–Labrador Shelf
Fisheries Oceanography, 2007Co-Authors: César Fuentes-yaco, P Koeller, Shubha Sathyendranath, Trevor PlattAbstract:We examined latitudinal and temporal changes in the availability of food for young shrimp (Pandalus borealis) on the Newfoundland–Labrador Shelf, using a suite of quantitative characteristics of the spring phytoplankton bloom determined from satellite ocean colour data, including bloom initiation time, maximum chlorophyll concentration, timing of the maximum, and bloom duration. We found significant correlations between bloom intensity, timing, and the size of young shrimp. The results are discussed in relation to the observation that, since the early 1990s, carapace lengths of shrimp have been decreasing in many Northwest Atlantic stocks.
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decreasing shrimp Pandalus borealis sizes off newfoundland and labrador environment or fishing
Fisheries Oceanography, 2007Co-Authors: P Koeller, Cesar Fuentesyaco, Trevor PlattAbstract:During the 1990s, carapace length statistics including minimum size caught (Lmin), mean male and female lengths, size at sex transition (L50) and maximum size (Lmax) of northern shrimp (Pandalus borealis) decreased in commercial and survey catches off Newfoundland and Labrador. Decreased growth rates caused by decreases in per-capita food availability due to large population increases, exacerbated by increased metabolic demands from higher water temperatures in the mid-1990s, appear to be the main cause of the size decrease. Fishing could have had an accelerating effect on environmentally driven decreases in shrimp growth and size by ‘cropping’ the largest shrimp from the population. The greatest decreases in shrimp size occurred in Hudson Strait and the adjacent northern shelf, the area which also has the highest densities and largest shrimp. We hypothesize that the greater size decrease here resulted from decreased primary production from decreased nutrient flux into the euphotic zone, caused by increased atmospheric warming, freshwater runoff and stratification during the warming trend of the 1990s.
Cesar Fuentesyaco - One of the best experts on this subject based on the ideXlab platform.
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ocean surface characteristics influence recruitment variability of populations of northern shrimp Pandalus borealis in the northwest atlantic
Ices Journal of Marine Science, 2011Co-Authors: Patrick Ouellet, Cesar Fuentesyaco, Shubha Sathyendranath, Trevor Platt, P Koeller, Louise Savard, Helle SiegstadAbstract:Remotely sensed data were used to derive simple ecosystem indicators for four regions of the Northwest Atlantic to test the hypothesis that sea surface temperatures (SSTs) and spring phytoplankton bloom characteristics (initiation, timing, intensity, and duration) have a significant influence on larval survival and recruitment of northern shrimp (Pandalus borealis). For all years (1998 – 2007) and regions, hatching was after the initiation of the bloom and before or after the bloom reached its maximum intensity. The results suggest that the best survival of larvae is associated with high warming rates of SST following hatching, but in very cold environments, warm temperatures at hatching seem to be important for larval survival. The analyses also indicate that larval survival is supported by an early, long phytoplankton bloom which attains high concentrations of chlorophyll a. The results demonstrate the potential of remotely sensed data for deriving simple population-specific ecosystem indicators for potential use in building operational recruitment models for predicting changes in northern shrimp abundance.
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shrimp Pandalus borealis growth and timing of the spring phytoplankton bloom on the newfoundland labrador shelf
Fisheries Oceanography, 2007Co-Authors: Cesar Fuentesyaco, P Koeller, Shubha Sathyendranath, Trevor PlattAbstract:We examined latitudinal and temporal changes in the availability of food for young shrimp (Pandalus borealis) on the Newfoundland–Labrador Shelf, using a suite of quantitative characteristics of the spring phytoplankton bloom determined from satellite ocean colour data, including bloom initiation time, maximum chlorophyll concentration, timing of the maximum, and bloom duration. We found significant correlations between bloom intensity, timing, and the size of young shrimp. The results are discussed in relation to the observation that, since the early 1990s, carapace lengths of shrimp have been decreasing in many Northwest Atlantic stocks.
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decreasing shrimp Pandalus borealis sizes off newfoundland and labrador environment or fishing
Fisheries Oceanography, 2007Co-Authors: P Koeller, Cesar Fuentesyaco, Trevor PlattAbstract:During the 1990s, carapace length statistics including minimum size caught (Lmin), mean male and female lengths, size at sex transition (L50) and maximum size (Lmax) of northern shrimp (Pandalus borealis) decreased in commercial and survey catches off Newfoundland and Labrador. Decreased growth rates caused by decreases in per-capita food availability due to large population increases, exacerbated by increased metabolic demands from higher water temperatures in the mid-1990s, appear to be the main cause of the size decrease. Fishing could have had an accelerating effect on environmentally driven decreases in shrimp growth and size by ‘cropping’ the largest shrimp from the population. The greatest decreases in shrimp size occurred in Hudson Strait and the adjacent northern shelf, the area which also has the highest densities and largest shrimp. We hypothesize that the greater size decrease here resulted from decreased primary production from decreased nutrient flux into the euphotic zone, caused by increased atmospheric warming, freshwater runoff and stratification during the warming trend of the 1990s.
Helle Siegstad - One of the best experts on this subject based on the ideXlab platform.
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environmental factors affecting recruitment of northern shrimp Pandalus borealis in west greenland waters
Marine Ecology Progress Series, 2012Co-Authors: Kai Wieland, Helle SiegstadAbstract:Survey estimates of northern shrimp Pandalus borealis biomass in West Greenland waters increased from about 178 000 t in 1998 to about 598 000 t in 2003. The increase in stock size was preceded by several consecutive years in which recruitment was substantially above average. Recruitment has been poor since then despite record high levels of female stock biomass. Ricker- type stock-recruitment functions did not indicate that the variability in recruitment was related to female biomass. Multiple regression analysis revealed that mean female length, ambient bottom temperature and biomass of Greenland halibut Reinhardtius hippoglossoides had the most impor- tant effect on the variations of the 'recruit per female biomass' time series for the years 1993 to 2011. Variables which did not contribute significantly to the model included biomass of Atlantic cod Gadus morhua. This can be explained by the low stock size of Atlantic cod throughout the major part of the study period. The final model explained 83% of the variation in the recruit per female biomass index. However, the observations for 5 out of the 19 years considered in the pres- ent study were outside the 95% confidence interval of the fitted model, possibly due to a mismatch between the timing of larval hatch and the timing of the phytoplankton bloom, which could not adequately be addressed due to data limitations.
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ocean surface characteristics influence recruitment variability of populations of northern shrimp Pandalus borealis in the northwest atlantic
Ices Journal of Marine Science, 2011Co-Authors: Patrick Ouellet, Cesar Fuentesyaco, Shubha Sathyendranath, Trevor Platt, P Koeller, Louise Savard, Helle SiegstadAbstract:Remotely sensed data were used to derive simple ecosystem indicators for four regions of the Northwest Atlantic to test the hypothesis that sea surface temperatures (SSTs) and spring phytoplankton bloom characteristics (initiation, timing, intensity, and duration) have a significant influence on larval survival and recruitment of northern shrimp (Pandalus borealis). For all years (1998 – 2007) and regions, hatching was after the initiation of the bloom and before or after the bloom reached its maximum intensity. The results suggest that the best survival of larvae is associated with high warming rates of SST following hatching, but in very cold environments, warm temperatures at hatching seem to be important for larval survival. The analyses also indicate that larval survival is supported by an early, long phytoplankton bloom which attains high concentrations of chlorophyll a. The results demonstrate the potential of remotely sensed data for deriving simple population-specific ecosystem indicators for potential use in building operational recruitment models for predicting changes in northern shrimp abundance.
Shubha Sathyendranath - One of the best experts on this subject based on the ideXlab platform.
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ocean surface characteristics influence recruitment variability of populations of northern shrimp Pandalus borealis in the northwest atlantic
Ices Journal of Marine Science, 2011Co-Authors: Patrick Ouellet, Cesar Fuentesyaco, Shubha Sathyendranath, Trevor Platt, P Koeller, Louise Savard, Helle SiegstadAbstract:Remotely sensed data were used to derive simple ecosystem indicators for four regions of the Northwest Atlantic to test the hypothesis that sea surface temperatures (SSTs) and spring phytoplankton bloom characteristics (initiation, timing, intensity, and duration) have a significant influence on larval survival and recruitment of northern shrimp (Pandalus borealis). For all years (1998 – 2007) and regions, hatching was after the initiation of the bloom and before or after the bloom reached its maximum intensity. The results suggest that the best survival of larvae is associated with high warming rates of SST following hatching, but in very cold environments, warm temperatures at hatching seem to be important for larval survival. The analyses also indicate that larval survival is supported by an early, long phytoplankton bloom which attains high concentrations of chlorophyll a. The results demonstrate the potential of remotely sensed data for deriving simple population-specific ecosystem indicators for potential use in building operational recruitment models for predicting changes in northern shrimp abundance.
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shrimp Pandalus borealis growth and timing of the spring phytoplankton bloom on the newfoundland labrador shelf
Fisheries Oceanography, 2007Co-Authors: Cesar Fuentesyaco, P Koeller, Shubha Sathyendranath, Trevor PlattAbstract:We examined latitudinal and temporal changes in the availability of food for young shrimp (Pandalus borealis) on the Newfoundland–Labrador Shelf, using a suite of quantitative characteristics of the spring phytoplankton bloom determined from satellite ocean colour data, including bloom initiation time, maximum chlorophyll concentration, timing of the maximum, and bloom duration. We found significant correlations between bloom intensity, timing, and the size of young shrimp. The results are discussed in relation to the observation that, since the early 1990s, carapace lengths of shrimp have been decreasing in many Northwest Atlantic stocks.
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Shrimp (Pandalus borealis) growth and timing of the spring phytoplankton bloom on the Newfoundland–Labrador Shelf
Fisheries Oceanography, 2007Co-Authors: César Fuentes-yaco, P Koeller, Shubha Sathyendranath, Trevor PlattAbstract:We examined latitudinal and temporal changes in the availability of food for young shrimp (Pandalus borealis) on the Newfoundland–Labrador Shelf, using a suite of quantitative characteristics of the spring phytoplankton bloom determined from satellite ocean colour data, including bloom initiation time, maximum chlorophyll concentration, timing of the maximum, and bloom duration. We found significant correlations between bloom intensity, timing, and the size of young shrimp. The results are discussed in relation to the observation that, since the early 1990s, carapace lengths of shrimp have been decreasing in many Northwest Atlantic stocks.
