GLORIA

GEOMAR Library Ocean Research Information Access

X

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Online Resource
    Online Resource
    Comment on “Does the fall phytoplankton bloom control recruitment of Georges Bank haddock, Melanogrammus aeglefinus , through parental condition?”Appears in Can. J. Fish. Aquat. Sci. 65 : 1076–1086.
    Canadian Science Publishing ; 2009
    In:  Canadian Journal of Fisheries and Aquatic Sciences Vol. 66, No. 5 ( 2009-05), p. 869-872
    Details
    In: Canadian Journal of Fisheries and Aquatic Sciences, Canadian Science Publishing, Vol. 66, No. 5 ( 2009-05), p. 869-872
    Abstract: In the paper “Does the fall phytoplankton bloom control recruitment of Georges Bank haddock, Melanogrammus aeglefinus , through parental condition?”, Friedland et al. (Can. J. Fish. Aquat. Sci. 65(6): 1076–1086, 2008) examine a sizable number of hypotheses aiming to explain the recruitment patterns observed in Georges Bank haddock. The authors focus on a correlation between the size of the autumnal phytoplankton bloom and the survivor ratio (recruitment), concluding this to be the main factor determining recruitment, via the mechanism of adult condition at the time of spawning. Here we examine this result in close detail and re-analyse some of the data presented in the paper. We show that the recruitment metric upon which Friedland et al. base their conclusions inadvertently biases the analysis in favour of high recruitment events and against low recruitments. As a consequence, Friedland et al. disregard correlations that are, in fact, significant. Furthermore, we show that the parental condition hypothesis hinges upon a single, highly uncertain data point, without which the correlation is no longer significant. We find that evidence for the parental condition hypothesis is weak, and that in performing the analysis in the chosen manner, Friedland et al. have overlooked alternative hypotheses.
    Type of Medium: Online Resource
    ISSN: 0706-652X , 1205-7533
    URL: Article
    DOI: 10.1139/F09-043
    Language: English
    Publisher: Canadian Science Publishing
    Publication Date: 2009
    detail.hit.zdb_id: 7966-2
    detail.hit.zdb_id: 1473089-3
    SSG: 21,3
    SSG: 12
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 2
    Online Resource
    Online Resource
    Recruitment in a changing environment: the 2000s North Sea herring recruitment failure
    Oxford University Press (OUP) ; 2009
    In:  ICES Journal of Marine Science Vol. 66, No. 2 ( 2009-03-01), p. 272-277
    Details
    In: ICES Journal of Marine Science, Oxford University Press (OUP), Vol. 66, No. 2 ( 2009-03-01), p. 272-277
    Abstract: Payne, M. R., Hatfield, E. M. C., Dickey-Collas, M., Falkenhaug, T., Gallego, A., Gröger, J., Licandro, P., Llope, M., Munk, P., Röckmann, C., Schmidt, J. O., and Nash, R. D. M. 2009. Recruitment in a changing environment: the 2000s North Sea herring recruitment failure. – ICES Journal of Marine Science, 66: 272–277. Environmentally induced change appears to be impacting the recruitment of North Sea herring (Clupea harengus). Despite simultaneously having a large adult population, historically low exploitation, and Marine Stewardship Council accreditation (implying sustainability), there have been an unprecedented 6 sequential years of poor juvenile production (recruitment). Analysis suggests that the poor recruitment arises during the larval overwintering phase, with recent survival rates greatly reduced. Contemporary warming of the North Sea has caused significant changes in the plankton community, and a recently identified regime shift around 2000 shows close temporal agreement with the reduced larval survival. It is, therefore, possible that we are observing the first consequences of this planktonic change for higher trophic levels. There is no indication of a recovery in recruitment in the short term. Fishing mortality is currently outside the agreed management plan, and forecasts show a high risk of the stock moving outside safe biological limits soon, potentially precipitating another collapse of the stock. However, bringing the realized fishing mortality back in line with the management plan would likely alleviate the problem. This illustrates again that recruitment is influenced by more than just spawning-stock biomass, and that changes in other factors can be of equal, or even greater, importance. In such dynamically changing environments, recent management success does not necessarily guarantee future sustainability.
    Type of Medium: Online Resource
    ISSN: 1095-9289 , 1054-3139
    URL: Article
    DOI: 10.1093/icesjms/fsn211
    Language: English
    Publisher: Oxford University Press (OUP)
    Publication Date: 2009
    detail.hit.zdb_id: 2463178-4
    detail.hit.zdb_id: 1468003-8
    detail.hit.zdb_id: 29056-7
    SSG: 12
    SSG: 21,3
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 3
    Online Resource
    Online Resource
    Precisely wrong or vaguely right: simulations of noisy discard data and trends in fishing effort being included in the stock assessment of North Sea plaice
    Oxford University Press (OUP) ; 2007
    In:  ICES Journal of Marine Science Vol. 64, No. 9 ( 2007-12-01), p. 1641-1649
    Details
    In: ICES Journal of Marine Science, Oxford University Press (OUP), Vol. 64, No. 9 ( 2007-12-01), p. 1641-1649
    Abstract: Dickey-Collas, M., Pastoors, M. A, and van Keeken, O. A. 2007. Precisely wrong or vaguely right: simulations of noisy discard data and trends in fishing effort being included in the stock assessment of North Sea plaice. – ICES Journal of Marine Science, 64: 000–000. ICES stock assessments of North Sea plaice are routinely carried out with eXtended Survivors Analysis (XSA), based on landings and survey data. Recently, the assessments included data on discarded young fish, sampled with high variance. Fishing effort has been declining since the mid-1990s, so conditioning the estimated fishing mortality (F) on the recent past could introduce bias into the perceived stock size. Simulated populations with North Sea plaice-like characteristics are used to explore the dependence of the perceived stock dynamics on the inclusion of discards data at different sampling noise, using the same methods and XSA settings as ICES. The sensitivities of the results were tested against different trends in fishing effort and recruitment, and different scenarios for “shrinkage” (i.e. the way in which the past is used to estimate the most recent fishing mortality). Within the bounds of the simulation assumptions, the perception of population trends from an XSA stock assessment can be biased when there are trends in fishing effort: decreasing effort leads to underestimating SSB and overestimating F. When discards are not included, bias in SSB is greatest when effort decreases, and bias in F is greatest when effort increases. Bias in SSB and F were removed by including discard data, but at substantial loss of precision. If effort shows a clear trend and discards are substantial and estimated noisily, the recent trend in the target population may be hard to track with an XSA-type assessment methodology.
    Type of Medium: Online Resource
    ISSN: 1095-9289 , 1054-3139
    URL: Article
    DOI: 10.1093/icesjms/fsm155
    Language: English
    Publisher: Oxford University Press (OUP)
    Publication Date: 2007
    detail.hit.zdb_id: 2463178-4
    detail.hit.zdb_id: 1468003-8
    detail.hit.zdb_id: 29056-7
    SSG: 12
    SSG: 21,3
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 4
    Online Resource
    Online Resource
    Mean daily growth of herring larvae in relation to temperature over a range of 5–20°C, based on weekly repeated cruises in the Greifswalder Bodden
    Oxford University Press (OUP) ; 2009
    In:  ICES Journal of Marine Science Vol. 66, No. 8 ( 2009-09-01), p. 1696-1701
    Details
    In: ICES Journal of Marine Science, Oxford University Press (OUP), Vol. 66, No. 8 ( 2009-09-01), p. 1696-1701
    Abstract: Oeberst, R., Dickey-Collas, M., and Nash, R. D. M. 2009. Mean daily growth of herring larvae in relation to temperature over a range of 5–20°C, based on weekly repeated cruises in the Greifswalder Bodden. – ICES Journal of Marine Science, 66: 1696–1701. Reported estimates of mean daily growth of herring larvae generally cover the temperature range 1–12°C and few estimates are available for temperatures 〉 15°C. We use larval surveys on Rügen spring-spawning herring in the Strelasund and the Greifswalder Bodden to estimate larval growth over a wider temperature range because the water temperature in that area normally increases from 5 to 20°C during the larval growth period (i.e. from spring to summer). This large temperature increase has a significant influence on the mean daily growth of herring larvae. Growth estimates were based on the modes of length frequencies observed at individual stations or accumulated over strata from consecutive surveys. Mean daily growth (G; mm d−1) of larvae was primarily determined by the ambient temperature (T) during the growth interval (5–7 d), resulting in the following relationship: G = 0.011 + 0.037 T. A non-linear function is also described. Growth rate was not length-dependent over the size range studied (5–20 mm). The study also showed that herring larvae were growing and surviving in temperatures up to 17.5°C.
    Type of Medium: Online Resource
    ISSN: 1095-9289 , 1054-3139
    URL: Article
    DOI: 10.1093/icesjms/fsp193
    Language: English
    Publisher: Oxford University Press (OUP)
    Publication Date: 2009
    detail.hit.zdb_id: 2463178-4
    detail.hit.zdb_id: 1468003-8
    detail.hit.zdb_id: 29056-7
    SSG: 12
    SSG: 21,3
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 5
    Online Resource
    Online Resource
    Genetic population structure of marine fish: mismatch between biological and fisheries management units
    Wiley ; 2009
    In:  Fish and Fisheries Vol. 10, No. 4 ( 2009-12), p. 361-395
    Details
    In: Fish and Fisheries, Wiley, Vol. 10, No. 4 ( 2009-12), p. 361-395
    Type of Medium: Online Resource
    ISSN: 1467-2960 , 1467-2979
    URL: Issue
    URL: Article
    DOI: 10.1111/faf.2009.10.issue-4
    DOI: 10.1111/j.1467-2979.2008.00324.x
    Language: English
    Publisher: Wiley
    Publication Date: 2009
    detail.hit.zdb_id: 2024569-5
    SSG: 21,3
    SSG: 12
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 6
    Online Resource
    Online Resource
    Temporal and spatial variability in growth and condition of dab (Limanda limanda) and sprat (Sprattus sprattus) larvae in the Irish Sea
    Wiley ; 2006
    In:  Fisheries Oceanography Vol. 15, No. 6 ( 2006-11), p. 490-507
    Details
    In: Fisheries Oceanography, Wiley, Vol. 15, No. 6 ( 2006-11), p. 490-507
    Type of Medium: Online Resource
    ISSN: 1054-6006 , 1365-2419
    URL: Issue
    URL: Article
    DOI: 10.1111/fog.2006.15.issue-6
    DOI: 10.1111/j.1365-2419.2006.00406.x
    Language: English
    Publisher: Wiley
    Publication Date: 2006
    detail.hit.zdb_id: 1214985-8
    detail.hit.zdb_id: 2020300-7
    SSG: 21,3
    SSG: 12
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 7
    Online Resource
    Online Resource
    Fecundity, atresia, and spawning strategies of Atlantic herring (Clupea harengus)
    Canadian Science Publishing ; 2009
    In:  Canadian Journal of Fisheries and Aquatic Sciences Vol. 66, No. 12 ( 2009-12), p. 2130-2141
    Details
    In: Canadian Journal of Fisheries and Aquatic Sciences, Canadian Science Publishing, Vol. 66, No. 12 ( 2009-12), p. 2130-2141
    Abstract: Atlantic herring ( Clupea harengus ) have contrasting spawning strategies, with apparently genetically similar fish “choosing” different spawning seasons, different egg sizes, and different spawning areas. In the North Sea, both autumn- and winter-spawning herring share the same summer feeding area but have different spawning areas. Females of both spawning types start their oocyte development in April–May. Oocyte development is influenced by the body energy content; during the maturation cycle, fecundity is down-regulated through atresia in relation to the actual body condition. Hence, fecundity estimates must account for the relative time of sampling. The down-regulation over the whole maturation period is approximately 20% in autumn- and 50% in winter-spawning herring. The development of the oocytes is the same for both spawning strategies until autumn when autumn spawners spawn a larger number of small eggs. In winter spawners, oocyte development and down-regulation of fecundity continues, resulting in larger eggs and lower number spawned. In theory, autumn and winter spawners could therefore switch spawning strategies, indicating a high level of reproductive plasticity.
    Type of Medium: Online Resource
    ISSN: 0706-652X , 1205-7533
    URL: Article
    DOI: 10.1139/F09-153
    Language: English
    Publisher: Canadian Science Publishing
    Publication Date: 2009
    detail.hit.zdb_id: 7966-2
    detail.hit.zdb_id: 1473089-3
    SSG: 21,3
    SSG: 12
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 8
    Online Resource
    Online Resource
    An investigation of seasonal and annual catches and discards of the Dutch pelagic freezer-trawlers in Mauritania, Northwest Africa
    Elsevier BV ; 2006
    In:  Fisheries Research Vol. 77, No. 2 ( 2006-2), p. 184-191
    Details
    In: Fisheries Research, Elsevier BV, Vol. 77, No. 2 ( 2006-2), p. 184-191
    Type of Medium: Online Resource
    ISSN: 0165-7836
    URL: Article
    DOI: 10.1016/j.fishres.2005.08.012
    Language: English
    Publisher: Elsevier BV
    Publication Date: 2006
    detail.hit.zdb_id: 406532-3
    detail.hit.zdb_id: 1497860-X
    SSG: 21,3
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 9
    Online Resource
    Online Resource
    What do pelagic freezer-trawlers discard?
    Oxford University Press (OUP) ; 2008
    In:  ICES Journal of Marine Science Vol. 65, No. 4 ( 2008-05-01), p. 605-611
    Details
    In: ICES Journal of Marine Science, Oxford University Press (OUP), Vol. 65, No. 4 ( 2008-05-01), p. 605-611
    Abstract: Borges, L., van Keeken, O. A., van Helmond, A. T. M., Couperus, B., and Dickey-Collas, M. 2008. What do pelagic freezer-trawlers discard? – ICES Journal of Marine Science, 65: 605–611. Estimates of discards by the Dutch pelagic freezer-trawler fleet were derived based on data from observers on board commercial vessels. In all, 27 fishing trips of duration 2–5 weeks each were sampled between 2002 and 2005, covering the North Sea and the western waters of the British Isles. Different methods to estimate discards were compared, and raising these estimates by number of trips or by total landings did not greatly influence the annual estimates of total discards. Some 30 000 t of fish were discarded annually by the fleet, the commercial target species mackerel, herring, and horse mackerel being discarded most, with 41%, 19%, and 15% of the total discards by weight, respectively. The most commonly discarded non-commercial species was boarfish, accounting for 5% of total discards. Slippage accounts for 10% of all discards, and the most common species slipped is herring. There is extensive discarding of juvenile mackerel in the horse mackerel fishery, and to a lesser extent highgrading of mackerel in the same fishery.
    Type of Medium: Online Resource
    ISSN: 1095-9289 , 1054-3139
    URL: Article
    DOI: 10.1093/icesjms/fsn050
    Language: English
    Publisher: Oxford University Press (OUP)
    Publication Date: 2008
    detail.hit.zdb_id: 2463178-4
    detail.hit.zdb_id: 1468003-8
    detail.hit.zdb_id: 29056-7
    SSG: 12
    SSG: 21,3
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 10
    Online Resource
    Online Resource
    When is year-class strength determined in western Baltic herring?
    Oxford University Press (OUP) ; 2009
    In:  ICES Journal of Marine Science Vol. 66, No. 8 ( 2009-09-01), p. 1667-1672
    Details
    In: ICES Journal of Marine Science, Oxford University Press (OUP), Vol. 66, No. 8 ( 2009-09-01), p. 1667-1672
    Abstract: Oeberst, R., Klenz, B., Gröhsler, T., Dickey-Collas, M., Nash, R. D. M., and Zimmermann, C. 2009. When is year-class strength determined in western Baltic herring? – ICES Journal of Marine Science, 66: 1667–1672. Weekly surveys of larvae in the Strelasund and the Greifswalder Bodden were used to investigate when year-class strength is determined in western Baltic spring-spawning (WBSS) herring. An abundance metric of larvae reaching a length of 20 mm over the entire spawning season was constructed by accounting for increases in daily growth resulting from seasonal increases in temperature (5–20°C). The index was significantly correlated with the acoustic estimates of age-1 herring in the western Baltic Sea (r = 0.88) and with the estimates of year-class strength obtained from stock assessment (r = 0.65). Previous studies of herring elsewhere have reported that year-class strength is determined during the late larval stage, but we show that year-class strength can already be fixed at a larval length of only 20 mm. Although the index obtained may be used in stock assessment and predictions, the intriguing question remains, namely how can the signal of larval productivity from one single spawning component of WBSS herring reflect the year-class dynamics of the entire stock?
    Type of Medium: Online Resource
    ISSN: 1095-9289 , 1054-3139
    URL: Article
    DOI: 10.1093/icesjms/fsp143
    Language: English
    Publisher: Oxford University Press (OUP)
    Publication Date: 2009
    detail.hit.zdb_id: 2463178-4
    detail.hit.zdb_id: 1468003-8
    detail.hit.zdb_id: 29056-7
    SSG: 12
    SSG: 21,3
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...