Egg mortality and hatching rate of Baltic cod (Gadus morhua) in different salinities

1991 ◽  
Vol 111 (1) ◽  
pp. 29-32 ◽  
Author(s):  
A. Nissling ◽  
L. Westin
Keyword(s):  
Gadus Morhua ◽  
Hatching Rate ◽  
Egg Mortality ◽  
Baltic Cod

Early embryonic cleavage pattern, hatching success, and egg-lipid fatty acid composition: comparison between two cod (Gadus morhua) stocks

1997 ◽  
Vol 54 (10) ◽  
pp. 2410-2416 ◽  
Author(s):  
J Pickova ◽  
P C Dutta ◽  
P -O Larsson ◽  
A Kiessling
Keyword(s):  
Gadus Morhua ◽  
Hatching Success ◽  
Hatching Rate ◽  
Cleavage Pattern ◽  
Egg Viability ◽  
Lipid Fatty Acid ◽  
Embryonic Cleavage ◽  
The Baltic ◽  
Lipid Fatty Acid Composition ◽  
Baltic Cod

Baltic cod (Gadus morhua), from a brackish environment, were compared with oceanic (Skagerrak) cod in terms of early embryonic cleavage pattern, hatching success, and egg-lipid fatty acid composition. The influence of diet on these variables was investigated by analysing eggs from the Baltic stock, caught during three successive years and given controlled food for 24, 7, and 2 months, respectively, before the experiment commenced. Skagerrak cod eggs contained twice as much arachidonic acid (AA) in the phospholipid (PL) fraction as eggs from the Baltic cod, regardless of the length of time the Baltic cod had been kept in captivity and fed a control diet. Correlation between hatching rate and docosahexaenoic (DHA; 22:6n-3)/ eicosapentaenoic acid (EPA; 20:5n-3) ratio was significant (r2 = 0.56) as well as hatching rate and AA content of the PL fraction (r2 = 0.61). Symmetry during development, which was correlated to egg viability, was higher for eggs from Skagerrak than those from the Baltic stock. We suggest that AA content and DHA/EPA ratio of the PL fraction are important factors influencing egg viability and possibly also egg symmetry.\b Further, it appears that the factor(s) influencing the composition of the PL fraction is mostly related to stock rather than to diet.

Robustness of egg production methods as a fishery independent alternative to assess the Eastern Baltic cod stock (Gadus morhua callarias L.)

2012 ◽  
Vol 117-118 ◽  
pp. 75-85 ◽  
Author(s):  
Gerd Kraus ◽  
Hans-Harald Hinrichsen ◽  
Rüdiger Voss ◽  
Eske Teschner ◽  
Jonna Tomkiewicz ◽  
...  
Keyword(s):  
Egg Production ◽  
Gadus Morhua ◽  
Production Methods ◽  
Eastern Baltic ◽  
Baltic Cod

scholarly journals Deoxygenation impacts on Baltic Sea cod: Dramatic declines in ecosystem services of an iconic keystone predator

AMBIO ◽  
2021 ◽  
Author(s):  
Alessandro Orio ◽  
Yvette Heimbrand ◽  
Karin Limburg
Keyword(s):  
Ecosystem Services ◽  
Baltic Sea ◽  
Gadus Morhua ◽  
Generalized Additive Model ◽  
Additive Model ◽  
Maximum Length ◽  
The Baltic Sea ◽  
Hypoxic Zone ◽  
The Baltic ◽  
Baltic Cod

AbstractThe intensified expansion of the Baltic Sea’s hypoxic zone has been proposed as one reason for the current poor status of cod (Gadus morhua) in the Baltic Sea, with repercussions throughout the food web and on ecosystem services. We examined the links between increased hypoxic areas and the decline in maximum length of Baltic cod, a demographic proxy for services generation. We analysed the effect of different predictors on maximum length of Baltic cod during 1978–2014 using a generalized additive model. The extent of minimally suitable areas for cod (oxygen concentration ≥ 1 ml l−1) is the most important predictor of decreased cod maximum length. We also show, with simulations, the potential for Baltic cod to increase its maximum length if hypoxic areal extent is reduced to levels comparable to the beginning of the 1990s. We discuss our findings in relation to ecosystem services affected by the decrease of cod maximum length.

scholarly journals Factors affecting rule compliance with mesh size regulations in the Baltic cod trawl fishery

2007 ◽  
Vol 64 (8) ◽  
pp. 1603-1606 ◽  
Author(s):  
Petri Suuronen ◽  
Vesa Tschernij ◽  
Pekka Jounela ◽  
Daniel Valentinsson ◽  
P-O. Larsson
Keyword(s):  
Gadus Morhua ◽  
Management Practice ◽  
Mesh Size ◽  
Factors Affecting ◽  
Trawl Fishery ◽  
Management Measures ◽  
Gradual Introduction ◽  
Minimum Landing Size ◽  
The Baltic ◽  
Baltic Cod

Abstract Suuronen, P., Tschernij, V., Jounela, P., Valentinsson, D., and Larsson, P-O. 2007. Factors affecting rule compiance with mesh size regulations in the Baltic cod trawl fishery. – ICES Journal of Marine Science, 64: 1603–1606. In this study, we evaluate the efficiency and applicability of a series of gear-based management measures, enforced since 1990, whose purpose was to improve size selectivity in the trawl fishery for Baltic cod (Gadus morhua). In general, our study revealed that these measures had no marked effect on the capture and discard of young cod. Legal and illegal manipulation of selective codends was widespread. The adoption of a codend design that offered a modest increase in selectivity, but had a good match with the legislated minimum landing size (MLS), led to greater compliance, demonstrating that a mismatch between MLS and selectivity should be avoided. It was also obvious that, generally, the fishing industry did not tolerate large short-term losses. Our evaluation is that overly ambitious rules will be circumvented, and frequent and incoherent changes in the regulations represent bad management practice. A gradual introduction of restrictions and participation by fishers in the decision-making process will increase compliance.

scholarly journals Linking lipid dynamics with the reproductive cycle in Baltic cod Gadus morhua

2012 ◽  
Vol 471 ◽  
pp. 215-234 ◽  
Author(s):  
MC Røjbek ◽  
C Jacobsen ◽  
J Tomkiewicz ◽  
JG Støttrup
Keyword(s):  
Reproductive Cycle ◽  
Gadus Morhua ◽  
Lipid Dynamics ◽  
Baltic Cod
Sign in / Sign up

Export Citation Format

Share Document