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Adhesion of mechanically and chemically dispersed crude oil droplets to eggs of Atlantic cod (Gadus morhua) and haddock (Melanogrammus aeglefinus).

https://arctichealth.org/en/permalink/ahliterature299352
Source
Sci Total Environ. 2018 Nov 01; 640-641:138-143
Publication Type
Journal Article
Date
Nov-01-2018
Author
Bjørn Henrik Hansen
Lisbet Sørensen
Patricia Almeira Carvalho
Sonnich Meier
Andy M Booth
Dag Altin
Julia Farkas
Trond Nordtug
Author Affiliation
SINTEF Ocean AS, Environment and New Resources, Trondheim, Norway. Electronic address: bjorn.h.hansen@sintef.no.
Source
Sci Total Environ. 2018 Nov 01; 640-641:138-143
Date
Nov-01-2018
Language
English
Publication Type
Journal Article
Keywords
Animals
Gadiformes - physiology
Gadus morhua - physiology
Ovum - chemistry
Petroleum - analysis
Petroleum Pollution
Water Pollutants, Chemical - analysis
Abstract
Crude oil accidentally spilled into the marine environment undergoes natural weathering processes that result in oil components being dissolved into the water column or present in particulate form as dispersed oil droplets. Oil components dissolved in seawater are typically considered as more bioavailable to pelagic marine organisms and the main driver of crude oil toxicity, however, recent studies indicate that oil droplets may also contribute. The adhesion of crude oil droplets onto the eggs of pelagic fish species may cause enhanced transfer of oil components via the egg surface causing toxicity during the sensitive embryonic developmental stage. In the current study, we utilized an oil droplet dispersion generator to generate defined oil droplets sizes/concentrations and exposed Atlantic cod (Gadus morhua) and haddock (Melanogrammus aeglefinus) to investigate if the potential for dispersed oil droplets to adhere onto the surface of eggs was species-dependent. The influence of a commercial chemical dispersant on the adhesion process was also studied. A key finding was that the adhesion of oil droplets was significantly higher for haddock than cod, highlighting key differences and exposure risks between the two species. Scanning electron microscopy indicates that the differences in oil droplet adhesion may be driven by the surface morphology of the eggs. Another important finding was that the adhesion capacity of oil droplets to fish eggs is significantly reduced (cod 37.3%, haddock 41.7%) in the presence of the chemical dispersant.
PubMed ID
29859431 View in PubMed
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Climate based multi-year predictions of the Barents Sea cod stock.

https://arctichealth.org/en/permalink/ahliterature299316
Source
PLoS One. 2018; 13(10):e0206319
Publication Type
Journal Article
Research Support, Non-U.S. Gov't
Date
2018
Author
Marius Årthun
Bjarte Bogstad
Ute Daewel
Noel S Keenlyside
Anne Britt Sandø
Corinna Schrum
Geir Ottersen
Author Affiliation
Geophysical Institute, University of Bergen, 5007 Bergen, Norway.
Source
PLoS One. 2018; 13(10):e0206319
Date
2018
Language
English
Publication Type
Journal Article
Research Support, Non-U.S. Gov't
Keywords
Animals
Climate
Fisheries - trends
Forecasting
Gadus morhua - physiology
Linear Models
Oceans and Seas
Population Density
Seasons
Abstract
Predicting fish stock variations on interannual to decadal time scales is one of the major issues in fisheries science and management. Although the field of marine ecological predictions is still in its infancy, it is understood that a major source of multi-year predictability resides in the ocean. Here we show the first highly skilful long-term predictions of the commercially valuable Barents Sea cod stock. The 7-year predictions are based on the propagation of ocean temperature anomalies from the subpolar North Atlantic toward the Barents Sea, and the strong co-variability between these temperature anomalies and the cod stock. Retrospective predictions for the period 1957-2017 capture well multi-year to decadal variations in cod stock biomass, with cross-validated explained variance of over 60%. For lead times longer than one year the statistical long-term predictions show more skill than operational short-term predictions used in fisheries management and lagged persistence forecasts. Our results thus demonstrate the potential for ecosystem-based fisheries management, which could enable strategic planning on longer time scales. Future predictions show a gradual decline in the cod stock towards 2024.
PubMed ID
30356300 View in PubMed
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Comparing catch efficiency of five models of pot for use in a Newfoundland and Labrador cod fishery.

https://arctichealth.org/en/permalink/ahliterature297395
Source
PLoS One. 2018; 13(6):e0199702
Publication Type
Comparative Study
Journal Article
Research Support, Non-U.S. Gov't
Date
2018
Author
Phillip Meintzer
Philip Walsh
Brett Favaro
Author Affiliation
Department of Ocean Sciences, Memorial University of Newfoundland, St. John's, Newfoundland and Labrador, Canada.
Source
PLoS One. 2018; 13(6):e0199702
Date
2018
Language
English
Publication Type
Comparative Study
Journal Article
Research Support, Non-U.S. Gov't
Keywords
Algorithms
Animals
Body Size
Fisheries - economics - statistics & numerical data
Gadus morhua - physiology
Models, Theoretical
Newfoundland and Labrador
Regression Analysis
Abstract
Sustainability of commercial fisheries is best achieved when fishing gears are selective and have low impacts on bottom habitat. Pots (baited traps) are a fishing technology that typically has lower impacts than many other industrial gears. In this study we compared the efficiency of five models of pots (baited traps) designed to catch Atlantic cod (Gadus morhua) for use in Newfoundland and Labrador (NL)'s expanding cod fishery. We compared catch per unit effort (CPUE) and total lengths of cod across each pot type, as well as bycatch rates of each model. All pot types were successful at catching cod, but two models (the modified Newfoundland pot, and a four-entrance pot of our design) had highest CPUE. Specifically, we found that modifying Newfoundland pots increased their CPUE by 145% without a corresponding increase in bycatch. None of the pot types produced substantial amounts of bycatch. This study demonstrated that potting gear is an effective way to catch cod in NL, and that there is flexibility in which pot fishers can use, depending on the layout of their fishing vessel.
PubMed ID
29949631 View in PubMed
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Development of a new 'ultrametric' method for assessing spawning progression in female teleost serial spawners.

https://arctichealth.org/en/permalink/ahliterature305588
Source
Sci Rep. 2020 06 15; 10(1):9677
Publication Type
Journal Article
Research Support, Non-U.S. Gov't
Date
06-15-2020
Author
Kelli C Anderson
Maud Alix
Katerina Charitonidou
Anders Thorsen
Grethe Thorsheim
Kostas Ganias
Thassya C Dos Santos Schmidt
Olav Sigurd Kjesbu
Author Affiliation
Institute of Marine Research, PO Box 1870 Nordnes, NO-5817, Bergen, Norway. kelli.anderson@utas.edu.au.
Source
Sci Rep. 2020 06 15; 10(1):9677
Date
06-15-2020
Language
English
Publication Type
Journal Article
Research Support, Non-U.S. Gov't
Keywords
Animals
Automation
Female
Gadus morhua - physiology
Oocytes - metabolism
Organ Size
Oviposition
Vitellogenesis
Workflow
Abstract
The collection and presentation of accurate reproductive data from wild fish has historically been somewhat problematic, especially for serially spawning species. Therefore, the aim of the current study was to develop a novel method of assessing female spawning status that is robust to variation in oocyte dynamics between specimens. Atlantic cod (Barents Sea stock) were used to develop the new 'ultrametric' method, that is based on the progressive depletion of the vitellogenic oocyte pool relative to the rather constant previtellogenic oocyte (PVO) pool. Fish were subsequently partitioned into one of four categories that accurately reflected changes in their oocyte size frequency distribution characteristics and gonadosomatic index throughout spawning. The ultrametric method overcomes difficulties associated with presence of bimodal oocyte distributions, oocyte tails, lack of clear hiatus region, and presence of free ova, and can be implemented at a single sampling point. Much of the workflow is fully automated, and the technique may circumvent the need for histological analysis depending on the desired outcome. The ultrametric method differs from the traditional autodiametric method in that PVOs can be separated by ultrasonication and then enumerated, and ovarian homogeneity is not a mandatory requirement per se. The method is designed for determinate spawners but might be extended to include indeterminate spawners.
PubMed ID
32541862 View in PubMed
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Effect of a fish stock's demographic structure on offspring survival and sensitivity to climate.

https://arctichealth.org/en/permalink/ahliterature291333
Source
Proc Natl Acad Sci U S A. 2017 02 07; 114(6):1347-1352
Publication Type
Journal Article
Research Support, Non-U.S. Gov't
Date
02-07-2017
Author
Leif Christian Stige
Natalia A Yaragina
Øystein Langangen
Bjarte Bogstad
Nils Chr Stenseth
Geir Ottersen
Author Affiliation
Centre for Ecological and Evolutionary Synthesis, Department of Biosciences, University of Oslo, N-0316 Oslo, Norway; n.c.stenseth@ibv.uio.no l.c.stige@ibv.uio.no.
Source
Proc Natl Acad Sci U S A. 2017 02 07; 114(6):1347-1352
Date
02-07-2017
Language
English
Publication Type
Journal Article
Research Support, Non-U.S. Gov't
Keywords
Animals
Climate
Conservation of Natural Resources - methods
Female
Fisheries
Gadus morhua - physiology
Geography
Larva - physiology
Male
Norway
Oceans and Seas
Ovum - physiology
Population Dynamics
Population Growth
Russia
Abstract
Commercial fishing generally removes large and old individuals from fish stocks, reducing mean age and age diversity among spawners. It is feared that these demographic changes lead to lower and more variable recruitment to the stocks. A key proposed pathway is that juvenation and reduced size distribution causes reduced ranges in spawning period, spawning location, and egg buoyancy; this is proposed to lead to reduced spatial distribution of fish eggs and larvae, more homogeneous ambient environmental conditions within each year-class, and reduced buffering against negative environmental influences. However, few, if any, studies have confirmed a causal link from spawning stock demographic structure through egg and larval distribution to year class strength at recruitment. We here show that high mean age and size in the spawning stock of Barents Sea cod (Gadus morhua) is positively associated with high abundance and wide spatiotemporal distribution of cod eggs. We find, however, no support for the hypothesis that a wide egg distribution leads to higher recruitment or a weaker recruitment-temperature correlation. These results are based on statistical analyses of a spatially resolved data set on cod eggs covering a period (1959-1993) with large changes in biomass and demographic structure of spawners. The analyses also account for significant effects of spawning stock biomass and a liver condition index on egg abundance and distribution. Our results suggest that the buffering effect of a geographically wide distribution of eggs and larvae on fish recruitment may be insignificant compared with other impacts.
Notes
Cites: Proc Biol Sci. 2012 Jan 22;279(1727):275-83 PMID 21676978
Cites: Proc Natl Acad Sci U S A. 2012 Jun 5;109(23):8995-9 PMID 22615381
Cites: Glob Chang Biol. 2015 Mar 10;:null PMID 25758656
Cites: Proc Natl Acad Sci U S A. 2014 Mar 4;111(9):3478-83 PMID 24550465
Cites: J Anim Ecol. 2016 May;85(3):692-704 PMID 26781671
Cites: Glob Chang Biol. 2015 Apr;21(4):1521-30 PMID 25336028
Cites: Biol Lett. 2010 Apr 23;6(2):261-4 PMID 19923140
Cites: Science. 1995 Aug 4;269(5224):676-9 PMID 17758812
PubMed ID
28115694 View in PubMed
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Estimating the impact of petroleum substances on survival in early life stages of cod (Gadus morhua) using the dynamic energy budget theory.

https://arctichealth.org/en/permalink/ahliterature264864
Source
Mar Environ Res. 2014 Oct;101:60-8
Publication Type
Article
Date
Oct-2014
Author
Chris Klok
Trond Nordtug
Jacqueline E Tamis
Source
Mar Environ Res. 2014 Oct;101:60-8
Date
Oct-2014
Language
English
Publication Type
Article
Keywords
Animals
Environmental Exposure
Fisheries
Gadus morhua - physiology
Petroleum - toxicity
Petroleum Pollution
Abstract
To estimate the impact of accidental oil-spills on cod fisheries a model framework is developed in which a Dynamic Energy Budget (DEB) model is applied to assess mortality caused by petroleum substances in early life stages. In this paper we report on a literature search and DEB analyses, aiming for cod specific DEB-parameters. Furthermore, we explored the relevance of Fathead minnow DEB-parameters as surrogate by comparing LC50 values calculated from DEB-parameters with literature. Cod specific DEB-parameters could not be estimated based on available literature. LC50 values calculated from Fathead minnow DEB-parameters were higher than literature LC50 for early life stages of fish. Applying an extrapolation factor of 50 to the DEB-parameters resulted in LC50 values that were below literature irrespective of life stage. Therefore, we propose to use the last as an estimate for early life stages in cod and recommend relevant experiments with individual petroleum substances on cod.
PubMed ID
25244299 View in PubMed
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Examination of fine-scale spatial-temporal overlap and segregation between two closely related congeners Gadus morhua and Gadus ogac in coastal Newfoundland.

https://arctichealth.org/en/permalink/ahliterature257345
Source
J Fish Biol. 2014 Sep;85(3):713-35
Publication Type
Article
Date
Sep-2014
Author
D C Knickle
G A Rose
Author Affiliation
Centre for Fisheries Ecosystems Research, Fisheries and Marine Institute of Memorial University of Newfoundland, P. O. Box 4920, St John's, NL, A1C 5R3, Canada.
Source
J Fish Biol. 2014 Sep;85(3):713-35
Date
Sep-2014
Language
English
Publication Type
Article
Keywords
Acoustics
Animal Identification Systems
Animals
Gadiformes - physiology
Gadus morhua - physiology
Homing Behavior
Newfoundland and Labrador
Periodicity
Seasons
Spatio-Temporal Analysis
Abstract
The spatial and temporal movement patterns of sympatric juvenile Atlantic cod Gadus morhua and Greenland cod Gadus ogac were studied using high-resolution radio-acoustic positioning in a coastal area of Newfoundland during the summers of 2009 and 2010. A total of 20 fish (10 G. ogac and 10 G. morhua) were equipped with acoustic transmitters and monitored for periods up to 23 days. Most fishes showed high site fidelity with mean residence times of 12·4 (G. morhua) and 14·4 days (G. ogac). A few individuals showed a transient use of the study area, ranging distances up to c. 4 km. Mean daily home ranges [95% kernel utilization distributions (KUDs)] and core activity areas were significantly larger for G. morhua (3·8 and 0·5 ha) than for G. ogac (2·7 and 0·3 ha). Home ranges were not related to total length (LT ) for G. morhua but showed a weak positive relationship for G. ogac. Gadus morhua occupied larger areas during the day while G. ogac occupied slightly larger areas at night. Mean rates of movement for G. ogac and G. morhua ranged from 0·83 to 1·24 and 0·76 to 1·76 LT s(-1) , respectively, and were highest during crepuscular periods. Overall, G. morhua were wider ranging, moved at faster rates and were active throughout the diel cycle compared to G. ogac of the same size. It is suggested that differential use of space and activity periods plays an important role in the successful coexistence of these two species.
PubMed ID
25041096 View in PubMed
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Forecasting future recruitment success for Atlantic cod in the warming and acidifying Barents Sea.

https://arctichealth.org/en/permalink/ahliterature295325
Source
Glob Chang Biol. 2018 01; 24(1):526-535
Publication Type
Journal Article
Research Support, Non-U.S. Gov't
Date
01-2018
Author
Stefan Koenigstein
Flemming T Dahlke
Martina H Stiasny
Daniela Storch
Catriona Clemmesen
Hans-Otto Pörtner
Author Affiliation
University of Bremen, Bremen, Germany.
Source
Glob Chang Biol. 2018 01; 24(1):526-535
Date
01-2018
Language
English
Publication Type
Journal Article
Research Support, Non-U.S. Gov't
Keywords
Adaptation, Physiological
Animals
Climate change
Ecosystem
Gadus morhua - physiology
Larva
Oceans and Seas
Population Dynamics
Reproduction
Temperature
Abstract
Productivity of marine fish stocks is known to be affected by environmental and ecological drivers, and global climate change is anticipated to alter recruitment success of many stocks. While the direct effects of environmental drivers on fish early life stage survival can be quantified experimentally, indirect effects in marine ecosystems and the role of adaptation are still highly uncertain. We developed an integrative model for the effects of ocean warming and acidification on the early life stages of Atlantic cod in the Barents Sea, termed SCREI (Simulator of Cod Recruitment under Environmental Influences). Experimental results on temperature and CO2 effects on egg fertilization, egg and larval survival and development times are incorporated. Calibration using empirical time series of egg production, temperature, food and predator abundance reproduces age-0 recruitment over three decades. We project trajectories of recruitment success under different scenarios and quantify confidence limits based on variation in experiments. A publicly accessible web version of the SCREI model can be run under www.oceanchange.uni-bremen.de/;SCREI. Severe reductions in average age-0 recruitment success of Barents Sea cod are projected under uncompensated warming and acidification toward the middle to end of this century. Although high population stochasticity was found, considerable rates of evolutionary adaptation to acidification and shifts in organismal thermal windows would be needed to buffer impacts on recruitment. While increases in food availability may mitigate short-term impacts, an increase in egg production achieved by stock management could provide more long-term safety for cod recruitment success. The SCREI model provides a novel integration of multiple driver effects in different life stages and enables an estimation of uncertainty associated with interindividual and ecological variation. The model thus helps to advance toward an improved empirical foundation for quantifying climate change impacts on marine fish recruitment, relevant for ecosystem-based assessments of marine systems under climate change.
PubMed ID
28755499 View in PubMed
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Harvest Pressure on Coastal Atlantic Cod (Gadus morhua) from Recreational Fishing Relative to Commercial Fishing Assessed from Tag-Recovery Data.

https://arctichealth.org/en/permalink/ahliterature274950
Source
PLoS One. 2016;11(3):e0149595
Publication Type
Article
Date
2016
Author
Alf Ring Kleiven
Albert Fernandez-Chacon
Jan-Harald Nordahl
Even Moland
Sigurd Heiberg Espeland
Halvor Knutsen
Esben Moland Olsen
Source
PLoS One. 2016;11(3):e0149595
Date
2016
Language
English
Publication Type
Article
Keywords
Animals
Fisheries
Gadus morhua - physiology
Geography
Models, Theoretical
Norway
Recreation
Reward
Survival Analysis
Abstract
Marine recreational fishing is a popular outdoor activity. However, knowledge about the magnitude of recreational catches relative to commercial catches in coastal fisheries is generally sparse. Coastal Atlantic cod (Gadus morhua) is a target species for recreational fishers in the North Atlantic. In Norway, recreational fishers are allowed to use a variety of traps and nets as well as long-line and rod and line when fishing for cod. From 2005 to 2013, 9729 cod (mean size: 40 cm, range: 15-93 cm) were tagged and released in coastal Skagerrak, southeast Norway. Both high-reward (NOK 500) and low-reward tags (NOK 50) were used in this study. Because some harvested fish (even those posting high-reward tags) may go unreported by fishers, reporting rates were estimated from mark-recovery models that incorporate detection parameters in their structure, in addition to survival and mortality estimates. During 2005 to 2013, a total of 1707 tagged cod were recovered and reported by fishers. We estimate the overall annual survival to be 33% (SE 1.5). Recreational rod and line fishing were responsible for 33.7% (SE 2.4) of total mortality, followed by commercial fisheries (15.1% SE 0.8) and recreational fixed gear (6.8% SE 0.4). Natural mortality was 44.4% (SE 2.5) of total mortality. Our findings suggest that recreational fishing-rod and line fishing in particular-is responsible for a substantial part of fishing mortality exerted on coastal cod in southern Norway.
Notes
Cites: PLoS One. 2012;7(2):e3121622363583
Cites: Mol Ecol. 2003 Feb;12(2):385-9412535089
Cites: Biometrics. 2003 Mar;59(1):43-5312762440
Cites: Proc Biol Sci. 2004 Jul 7;271(1546):1337-4415306331
Cites: Science. 2004 Sep 24;305(5692):1958-6015331771
Cites: Science. 2005 Jun 10;308(5728):1621-315947186
Cites: Biometrics. 2005 Jun;61(2):442-716011690
Cites: Proc Biol Sci. 2006 May 7;273(1590):1085-9216600885
Cites: PLoS One. 2009;4(2):e457019240812
Cites: Ecol Lett. 2009 Jul;12(7):622-3119453620
Cites: Ecology. 2010 Oct;91(10):2918-3021058552
Cites: Mol Ecol. 2011 Feb;20(4):768-8321199035
Erratum In: PLoS One. 2016;11(7):e015922027391096
PubMed ID
26959371 View in PubMed
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Intra-annual variation in feeding of Atlantic cod Gadus morhua: the importance of ephemeral prey bursts.

https://arctichealth.org/en/permalink/ahliterature304826
Source
J Fish Biol. 2020 Nov; 97(5):1507-1519
Publication Type
Journal Article
Date
Nov-2020
Author
Peter Grønkjaer
Rasmus Ottosen
Thor Joensen
Lee Reeve
Einar E Nielsen
Rasmus Hedeholm
Author Affiliation
Department of Bioscience, Aquatic Biology, Aarhus University, Aarhus, Denmark.
Source
J Fish Biol. 2020 Nov; 97(5):1507-1519
Date
Nov-2020
Language
English
Publication Type
Journal Article
Keywords
Animals
Biomass
Diet
Energy Metabolism - physiology
Feeding Behavior - physiology
Gadus morhua - physiology
Gastrointestinal Contents
Greenland
Seasons
Abstract
Seasonal prey bursts are important for the life cycles and energy budgets of many predators. This study documents the diet and, especially, the importance of the ephemeral occurrence of capelin as prey for Atlantic cod (Gadus morhua) in Godthaabsfjord, west Greenland, over an annual cycle. The cod showed clear differences in diet composition on the 11 sampling dates resulting in a spring-summer, late summer-autumn and winter cluster. Moreover, a single sampling date, 12 May, was defined by cod gorge feeding on spawning capelin, which led to average stomach contents 4.3 times higher than the average for the remaining sampling dates. Changes in nitrogen stable isotope values from 22 April to 7 July in cod liver and muscle tissue were used to calculate the consumption of capelin. Based on this, the consumption of capelin varied between 538 and 658?g wet weight for a 1.3 kg cod. Using published consumption/biomass estimates and observed growth rates, the capelin intake corresponds to 10.1%-33.3% of the annual food consumption and accounts for 28.1%-34.5% of the annual growth of the cod. The present study documents the omnivorous feeding mode of Atlantic cod but highlights the utilization and importance of ephemeral prey bursts for the annual energy budget of the cod. It is hypothesized that access to capelin is critical for the postspawning recovery of Godthaabsfjord cod.
PubMed ID
32875592 View in PubMed
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15 records – page 1 of 2.