The sublethal effects of a polychlorinated biphenyl (Aroclor 1254) diet on the Atlantic cod (Gadus morhua)

Abstract Weltersbach, M. S., and Strehlow, H. V. 2013. Dead or alive—estimating post-release mortality of Atlantic cod in the recreational fishery. – ICES Journal of Marine Science, 70: 864–872. Atlantic cod (Gadus morhua) is one of the most important commercial and recreational target species in European marine waters. Recent recreational fisheries surveys revealed that recreational cod catches and release rates are substantial compared to the commercial fishery, particularly in the western Baltic Sea. Despite high release rates, no literature exists exploring the post-release mortality of cod and potential sublethal effects after catch-and-release in recreational fisheries. This study investigates (i) the post-release mortality of undersized cod, (ii) potential factors affecting mortality, and (iii) consequences of the catch-and-release process on cod. During four experimental trials, western Baltic Sea cod were angled from a charter vessel and thereafter observed together with control fish in netpens for 10 d at holding temperatures between 6.2 and 19.8°C. Adjusted mortality rates for angled cod ranged from 0.0–27.3% (overall mean 11.2%). A logistic regression analysis revealed that bleeding and holding-water temperature were the only significant predictors of mortality. Slow hook injury healing (>10 d) and bacterial wound infections were observed in some surviving cod. The results will help to increase the accuracy of recreational cod removal estimates and thereby improve the management of western Baltic cod stock.

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Catch-and-release of Atlantic cod (Gadus morhua): post-release behaviour of acoustically pretagged fish in a natural marine environment

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/cjfas-2014-0290 ◽

2015 ◽

Vol 72 (2) ◽

pp. 252-261 ◽

Cited By ~ 20

Author(s):

Keno Ferter ◽

Klaas Hartmann ◽

Alf Ring Kleiven ◽

Even Moland ◽

Esben Moland Olsen

Keyword(s):

Large Scale ◽

Gadus Morhua ◽

Sublethal Effects ◽

Atlantic Cod ◽

Small Scale ◽

Marine Environments ◽

Vertical Movements ◽

Catch And Release ◽

Diel Vertical Migrations ◽

In The Wild

Studying the sublethal effects of catch-and-release (C&R) is challenging, as there are several potential sources of bias. For example, if behavioural alterations immediately after the release event are to be studied, separation of tagging effects from actual C&R effects is required, which is a challenge in the wild, particularly in marine environments. To investigate the effects of C&R on Atlantic cod (Gadus morhua) in their natural environment, 80 cod were caught in fyke nets, fitted with acoustic transmitters, and released. After recovery from tagging and handling for at least 14 days, nine individuals were recaptured and released at least once during experimental angling, following best release practice. All cod survived the C&R event and did not show any large-scale behavioural changes (i.e., changes in diel vertical migrations). However, analysis of small-scale vertical movements showed that three individuals underwent short-term alterations (e.g., reduced or increased swimming activity). This study showed that pretagging fish with acoustic transmitters before experimental angling is an option when investigating fish behaviour immediately after the release event in marine environments. Moreover, release guidelines for cod should be developed, as cod can recover quickly if caught in shallow waters (<20 m) and properly handled and released.

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Biological indications of contaminant exposure in Atlantic cod (Gadus morhua) in the Baltic Sea

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f08-042 ◽

2008 ◽

Vol 65 (6) ◽

pp. 1122-1134 ◽

Cited By ~ 10

Author(s):

Sabine Schnell ◽

Doris Schiedek ◽

Rolf Schneider ◽

Lennart Balk ◽

Pekka J. Vuorinen ◽

...

Keyword(s):

Baltic Sea ◽

Organic Contaminants ◽

Gadus Morhua ◽

Polychlorinated Biphenyl ◽

Atlantic Cod ◽

Human Impacts ◽

Toxic Substances ◽

The Baltic Sea ◽

Contaminant Exposure ◽

The Baltic

The Baltic Sea is exposed to severe human impacts. Besides eutrophication and overfishing, a variety of chemical contaminants threaten the health of fish. During a cruise in December 2001, Atlantic cod ( Gadus morhua ) were collected in the western and southern Baltic Sea, somatic condition factors were estimated, and different biomarkers of contaminant exposure were analysed. Additionally, various polychlorinated biphenyl congeners and organochlorine pesticides were measured in cod liver as more general indicators of pollution, not necessarily as the causative agents for biomarker signals. In most specimens, hepatic ethoxyresorufin-O-deethylase activity and bile 1-OH pyrene, a common polycyclic aromatic hydrocarbon metabolite, were detectable. Both features indicate an induction of the CYP1A biotransformation system in response to toxic substances. The increased occurrence of DNA adducts in some of the specimens also indicates the presence of genotoxic substances. Acetylcholinesterase was inhibited, an indication of exposure to organophosphates, carbamates, or certain heavy metals, particularly in specimens taken at Wismar Bay and off the Lithuanian coast. In general, spatial differences in the biomarker responses as well as in contaminant loads were found, suggesting differences in physiologically active concentrations and mixtures of organic contaminants in this ecosystem.

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Environmentally realistic exposure to weathered North Sea oil: Sublethal effects in Atlantic cod (Gadus morhua) and turbot (Scophthalmus maximus)

Journal of Toxicology and Environmental Health Part A ◽

10.1080/15287394.2017.1352195 ◽

2017 ◽

Vol 80 (16-18) ◽

pp. 895-906 ◽

Cited By ~ 2

Author(s):

Tor Fredrik Holth ◽

Audun Storset ◽

Anne Luise Ribeiro ◽

Ásdís Ólafsdóttir ◽

Halldór Pálmar Halldórsson ◽

...

Keyword(s):

North Sea ◽

Gadus Morhua ◽

Sublethal Effects ◽

Atlantic Cod ◽

Scophthalmus Maximus ◽

Turbot Scophthalmus Maximus

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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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