A nonparametric forecast model of inshore Atlantic cod (Gadus morhua) landings based on biomass, cumulative landings, and water temperature

Lengths at age of Atlantic cod (Gadus morhua) off the eastern coast of Canada vary up to three-fold among geographic regions, with Georges Bank and the southern Gulf of St. Lawrence being the regions of fastest and slowest growth, respectively. Colour-coded contour maps of length at ages 2–8 (n = 59 518) based on research vessel surveys between 1971 and 1992 clearly showed the spatial variations in size at age. Corresponding maps of July–September bottom water temperature appeared to reflect relative growth rate, whereas those for depth did not. A polynomial expansion of a temperature-based von Bertalanffy growth model appeared to fit the data well, with no residual patterns across most ages, lengths, temperatures, or years. Model predictions were also consistent with reported lengths at age for cod in other regions and countries. Declines in bottom water temperature over the past 5–10 years appear to be at least partly responsible for observed declines in size at age of the cod stock on the eastern Scotian Shelf.

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Thermal dynamics of ovarian maturation in Atlantic cod (Gadus morhua)

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f10-011 ◽

2010 ◽

Vol 67 (4) ◽

pp. 605-625 ◽

Cited By ~ 79

Author(s):

Olav Sigurd Kjesbu ◽

David Righton ◽

Maria Krüger-Johnsen ◽

Anders Thorsen ◽

Kathrine Michalsen ◽

...

Keyword(s):

Water Temperature ◽

Data Storage ◽

Egg Production ◽

Gadus Morhua ◽

Barents Sea ◽

Atlantic Cod ◽

Field Studies ◽

Irish Sea ◽

Oocyte Growth ◽

Thermal Dynamics

The timing and success of spawning in marine fish are of fundamental importance to population persistence and distribution and, for commercial species, sustainability. Their physiological processes of reproduction are regulated, in part, by water temperature, and therefore changes in marine climate may have dramatic effects on spawning performance. Using adult Atlantic cod ( Gadus morhua ) as a case study, we examined the links between water temperature, body size, vitellogenesis, and spawning time by conducting extensive laboratory and field studies. Our experiments documented that vitellogenesis generally starts at autumnal equinox and that oocyte growth and investment are greater in cod held at warmer temperatures. Furthermore, spawning occurred earlier when oocyte growth was more rapid. Large females spawned earlier than smaller females at warmer temperatures, but this effect vanished at colder temperatures. The experimental results were confirmed by measurements of oocyte growth collected from wild-caught cod in northern (Barents Sea) and southern (Irish Sea and North Sea) populations. The established, general model of oocyte maturation was consistent with published egg production curves of cod from these waters, considering relevant in situ temperatures recorded by individual data-storage tags on cod. These findings have considerable relevance for future studies of fish recruitment in relation to climate change.

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Influence of water temperature and oxygenation on the aerobic metabolic scope of Atlantic cod (Gadus morhua)

Journal of Sea Research ◽

10.1016/s1385-1101(00)00053-8 ◽

2000 ◽

Vol 44 (3-4) ◽

pp. 257-265 ◽

Cited By ~ 154

Author(s):

G. Claireaux ◽

D.M. Webber ◽

J.-P. Lagardère ◽

S.R. Kerr

Keyword(s):

Water Temperature ◽

Gadus Morhua ◽

Atlantic Cod ◽

Metabolic Scope ◽

Influence Of Water

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Effects of temperature on life history set the sensitivity to fishing in Atlantic cod Gadus morhua

Marine Ecology Progress Series ◽

10.3354/meps10943 ◽

2014 ◽

Vol 514 ◽

pp. 217-229 ◽

Cited By ~ 11

Author(s):

HY Wang ◽

LW Botsford ◽

JW White ◽

MJ Fogarty ◽

F Juanes ◽

...

Keyword(s):

Life History ◽

Gadus Morhua ◽

Atlantic Cod ◽

Effects Of Temperature

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Responses of Atlantic cod Gadus morhua head kidney leukocytes to phytase produced by gastrointestinal-derived bacteria

Fish Physiology and Biochemistry ◽

10.1007/s10695-009-9364-0 ◽

2009 ◽

Vol 36 (4) ◽

pp. 883-891 ◽

Cited By ~ 14

Author(s):

Carlo C. Lazado ◽

Christopher Marlowe A. Caipang ◽

Sanchala Gallage ◽

Monica F. Brinchmann ◽

Viswanath Kiron

Keyword(s):

Gadus Morhua ◽

Atlantic Cod ◽

Head Kidney

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Some recent data on sperm morphology and motility kinetics in Atlantic cod (Gadus morhua L.)

Fish Physiology and Biochemistry ◽

10.1007/s10695-020-00915-4 ◽

2021 ◽

Author(s):

Sayyed Mohammad Hadi Alavi ◽

Azadeh Hatef ◽

Ian A.E. Butts ◽

Olga Bondarenko ◽

Jacky Cosson ◽

...

Keyword(s):

Gadus Morhua ◽

Sperm Morphology ◽

Atlantic Cod

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Natural mortality from poor condition in Atlantic cod (Gadus morhua)

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f00-023 ◽

2000 ◽

Vol 57 (4) ◽

pp. 826-836 ◽

Cited By ~ 96

Author(s):

Jean-Denis Dutil ◽

Yvan Lambert

Keyword(s):

Gadus Morhua ◽

Atlantic Cod ◽

Negative Impact ◽

Fish Muscle ◽

Early Summer ◽

Wild Fish ◽

Natural Mortality ◽

Muscle Lactate ◽

Lactate Dehydrogenase Activity ◽

Poor Condition

The extent of energy depletion was assessed in Atlantic cod (Gadus morhua) in spring and early summer (1993-1995) to assess relationships between poor condition and natural mortality. Several indices of condition were compared in wild fish in the northern Gulf of St. Lawrence and in fish exposed to a prolonged period of starvation in laboratory experiments. Discriminant analyses classified only a small fraction of the wild fish as similar to cod that did not survive and a much larger fraction as similar to cod that survived starvation. This percentage increased from April to May and peaked in June 1993 and 1994. Condition factor and muscle somatic index allowed a clear distinction between live and dead fish. Muscle lactate dehydrogenase activity suggested that cod had experienced a period of negative growth early in 1993, 1994, and 1995. Fish classified as similar to starved individuals were characterized by a higher gonad to liver mass ratio than others. Reproduction may have a negative impact on survival not only in spring but also later into summer, as some individuals were found not to have recovered by late summer. This study shows that natural mortality from poor condition contributed to lower production in the early 1990s.

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