Modelling larval haddock Melanogrammus aeglefinus and cod Gadus morhua densities and mortality rates in hatchery mesocosms

A transect across southern Georges Bank in May 1983 showed higher levels of available prey for haddock (Melanogrammus aeglefinus) and cod (Gadus morhua) larvae at two stratified sites than at a well-mixed site. At the stratified sites, prey biomass was high (30–300 μg dry wt∙L−1) near the surface above the thermocline; values were lower and more uniform with depth (10–30 μg dry wt∙L−1) at the well-mixed site. Larval population centers generally coincided with prey biomass vertically. Recent growth in dry weight of haddock larvae as estimated by RNA–DNA ratio analysis was higher at the stratified sites (8–13%∙d−1) than at the well-mixed site (7%∙d−1). Larvae appeared to be in excellent condition at the stratified sites, but up to 50% of haddock larvae from the well-mixed site had RNA–DNA ratios in the range observed for starved larvae in the laboratory. Cod collected at the same site were in better condition and growing faster than haddock. The data support the hypotheses that (1) stratified conditions in the spring favor good growth and survival of haddock larvae and (2) cod larvae are better adapted to grow and survive in well-mixed waters at lower levels of available food than haddock larvae.

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Distinguishing Between One-Day-Old Cod (Gadus morhua) and Haddock (Melanogrammus aeglefinus) Eggs by Gas Chromatography and SIMCA Pattern Recognition

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f85-228 ◽

1985 ◽

Vol 42 (11) ◽

pp. 1823-1826 ◽

Cited By ~ 5

Author(s):

H. Knutsen ◽

E. Moksnes ◽

N. B. Vogt

Keyword(s):

Fatty Acids ◽

Pattern Recognition ◽

Gas Chromatography ◽

Multivariate Analysis ◽

Methyl Ester ◽

Gadus Morhua ◽

Melanogrammus Aeglefinus ◽

One Step ◽

High Resolution Gas Chromatography ◽

Haddock Melanogrammus Aeglefinus

Single cod (Gadus morhua) and haddock (Melanogrammus aeglefinus) eggs were acid hydrolized. All the fatty acids were liberated and converted to methyl ester in a one-step reaction. The nonpolar hexane extract was analyzed by high resolution gas chromatography (HRGC). Selected peaks, occurring in both types of samples and in all chromatograms, were used to create a matrix for multivariate analysis. We conclude that cod and haddock eggs can be distinguished using this method.

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Application of loop-mediated isothermal amplification (LAMP) for rapid detection of Atlantic cod (Gadus morhua), Pacific cod (Gadus macrocephalus) and haddock (Melanogrammus aeglefinus)

Molecular and Cellular Probes ◽

10.1016/j.mcp.2019.07.003 ◽

2019 ◽

Vol 47 ◽

pp. 101420

Author(s):

Yi Wang ◽

Junli Feng ◽

Xiaolan Tian

Keyword(s):

Rapid Detection ◽

Gadus Morhua ◽

Atlantic Cod ◽

Isothermal Amplification ◽

Melanogrammus Aeglefinus ◽

Pacific Cod ◽

Loop Mediated Isothermal Amplification ◽

Pacific Cod Gadus Macrocephalus ◽

Gadus Macrocephalus ◽

Haddock Melanogrammus Aeglefinus

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Analysis of the spatial distributions of mature cod (Gadus morhua) and haddock (Melanogrammus aeglefinus) abundance in the North Sea (1980–1999) using generalised additive models

Fisheries Research ◽

10.1016/j.fishres.2004.07.002 ◽

2004 ◽

Vol 70 (1) ◽

pp. 17-25 ◽

Cited By ~ 66

Author(s):

Richard Hedger ◽

Eddie McKenzie ◽

Mike Heath ◽

Peter Wright ◽

Beth Scott ◽

...

Keyword(s):

North Sea ◽

Gadus Morhua ◽

Additive Models ◽

Melanogrammus Aeglefinus ◽

Spatial Distributions ◽

Generalised Additive Models ◽

The North ◽

The North Sea ◽

Haddock Melanogrammus Aeglefinus

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Fecundity estimation of Atlantic cod (Gadus morhua) and haddock (Melanogrammus aeglefinus) of Georges Bank: Application of the autodiametric method

Fisheries Research ◽

10.1016/j.fishres.2009.04.011 ◽

2009 ◽

Vol 99 (1) ◽

pp. 47-54 ◽

Cited By ~ 21

Author(s):

Alexandre Alonso-Fernández ◽

Ann Carole Vallejo ◽

Fran Saborido-Rey ◽

Hilario Murua ◽

Edward A. Trippel

Keyword(s):

Gadus Morhua ◽

Atlantic Cod ◽

Melanogrammus Aeglefinus ◽

Georges Bank ◽

Haddock Melanogrammus Aeglefinus

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The vertical separation of fish in the aft end of a demersal trawl

ICES Journal of Marine Science ◽

10.1093/icesjms/fsp034 ◽

2009 ◽

Vol 66 (4) ◽

pp. 772-777 ◽

Cited By ~ 24

Author(s):

Ludvig Ahm Krag ◽

René Holst ◽

Niels Madsen

Keyword(s):

Vertical Distribution ◽

Gadus Morhua ◽

Melanogrammus Aeglefinus ◽

Multinomial Model ◽

Vertical Separation ◽

Commercially Important ◽

Merlangius Merlangus ◽

The Vertical Distribution ◽

Haddock Melanogrammus Aeglefinus ◽

Important Fish

Abstract Krag, L. A., Holst, R., and Madsen, N. 2009. The vertical separation of fish in the aft end of a demersal trawl. – ICES Journal of Marine Science, 66: 772–777. Two multi-compartment separator frames were used to study the vertical separation of some commercially important fish species in the aft end of a trawl, with the aim of separating cod (Gadus morhua) from other species. A non-linear multinomial model with random effects was used to analyse the data and to compare the performance of the two frames. The vertical distribution of cod in the aft end of the trawl was close to uniform, whereas haddock (Melanogrammus aeglefinus), whiting (Merlangius merlangus), plaice (Pleuronectes platessa), and lemon sole (Microstomus kitt) showed more uneven distributions. The use of guiding bars in the separator frame significantly (p < 0.05) increased the catch of cod, plaice, and lemon sole in the upper compartment. The vertical separation of cod was density-dependent; high densities of fish resulted in a more uniform distribution of cod. The species separations found differ from those reported from the studies of species separation in the region of the trawl mouth.

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Recruitment to Northwest Atlantic Cod (Gadus morhua) and Haddock (Melanogrammus aeglefinus) Stocks: Influence of Stock Size and Climate

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f87-004 ◽

1987 ◽

Vol 44 (1) ◽

pp. 26-39 ◽

Cited By ~ 70

Author(s):

J. Anthony Koslow ◽

Keith R. Thompson ◽

William Silvert

Keyword(s):

Large Scale ◽

Gadus Morhua ◽

Reproductive Output ◽

Atlantic Cod ◽

Low Frequency ◽

Melanogrammus Aeglefinus ◽

Northwest Atlantic ◽

Biological Variables ◽

Low Frequency Variability ◽

Haddock Melanogrammus Aeglefinus

Year-class success of both Atlantic cod (Gadus morhua) and haddock (Melanogrammus aeglefinus) stocks in the northwest Atlantic exhibits large-scale coherence and low-frequency variability with apparent periodicities of 10–20 yr. Several physical and biological variables in the region exhibit similar large-scale coherence and apparent periodicity. Multiple regression analysis indicates that year-class success in northwest Atlantic cod stocks tends to be associated with large-scale meteorological patterns and offshore winds. Recruitment to most haddock stocks from the Scotian Shelf to Georges Bank is negatively associated with abundance of 0-group mackerel, which may be due to predation over winter and/or to a combination of environmental features including sea-surface temperature, large-scale atmospheric pressure systems, and freshwater outflows. Statistical analyses often did not define a unique set of variables that best predicted fishery recruitment due to widespread intercorrelations among environmental processes and the likelihood that not all relevant processes entered directly into the analyses. There is little evidence that stock reproductive output during the study period was significantly related to year-class success.

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