GLORIA

GEOMAR Library Ocean Research Information Access

Your search history is empty.
feed icon rss

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
Filter
Document type
Keywords
Language
  • 1
    In: Journal of marine systems, New York, NY [u.a.] : Elsevier, 1990, 74(2008), 1/2, Seite 329-342, 0924-7963
    In: volume:74
    In: year:2008
    In: number:1/2
    In: pages:329-342
    Description / Table of Contents: We employed a coupled biologicalphysical, individual-based model (IBM) to estimate spatial and temporal changes in larval fish habitat suitability (the potential for areas to support survival and high rates of growth) of the German Bight, southern North Sea. In this Lagrangian approach, larvae were released into a size-structured prey field that was constructed from in situ measurements of the abundance and prosome lengths of stages of three copepods (Acartia spp., Temora longicornis, Pseudocalanus elongatus) collected on a station grid repeatedly sampled from February to October 2004. The choice of prey species and the model parameterisations for larval fish foraging and growth were based on field data collected for sprat (Sprattus sprattus) and other clupeid larvae. A series of 10-day simulations were conducted using 20 release locations to quantify spatialtemporal differences in projected larval sprat growth rates (mm d- 1) for mid-April, mid-May and mid-June 2004. Based upon an optimal foraging approach, modeled sprat growth rates agreed well with those measured in situ using larval fish ototliths. On the German GLOBEC station grid, our model predicted areas that were mostly unsuitable habitats (areas of low growth potential), e.g. north of the Frisian Islands, and others that were consistently suitable habitats (areas that had high growth potential), e.g. in the inner German Bight. In some instances, modelled larvae responded rapidly (~ 5 days) to changing environmental characteristics experienced along their drift trajectory, a result that appears reasonable given the dynamic nature of frontal regions such as our study area in the southern North Sea.
    Type of Medium: Online Resource
    Pages: graph. Darst.
    ISSN: 0924-7963
    Language: English
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 2
    In: Fisheries oceanography, Oxford [u.a.] : Wiley-Blackwell, 1997, 16(2007), 3, Seite 207-215, 1365-2419
    In: volume:16
    In: year:2007
    In: number:3
    In: pages:207-215
    Description / Table of Contents: Otolith increment width and larval fish data (length and weight) were used to develop an individual-based model (IBM) to describe daily resolved growth rates of North Sea herring (Clupea harengus) larvae (Autumn Spawners) caught during International Herring Larvae Surveys in the ICES area IVa from 1990 to 1998. The model combines sagittal otolith readings (core and individual increment measurements), larval standard length and weight data, and solves an over-determined set of linear system equations for all parameters using the method of least square residuals. The model consists of a matrix, which describes the increment width formation of 119 larvae, a vector containing their length/weight measurements, and a vector describing residuals. The solution vector yields age-dependent maximum somatic growth rates of herring larvae up to an age of 41 days with sizes ranging from 10 to 25 mm. The observed environmental temperature in which larvae dwelled was relatively uniform. Therefore, measured increment width was individually used to determine daily growth from any single larva in relation to their potential maximum growth under optimal feeding conditions. The results are discussed with respect to the spatial and temporal variability of larval occurrence. Finally, an analysis of error estimation of the larval growth characteristics is presented.
    Type of Medium: Online Resource
    Pages: graph. Darst.
    ISSN: 1365-2419
    Language: English
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 3
    Keywords: Hochschulschrift
    Type of Medium: Online Resource
    Pages: 1 Online-Ressource (96 Seiten = 11 MB) , Graphen, Karte
    Edition: 2020
    Language: German
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 4
    Type of Medium: Book
    Series Statement: ICES council meeting papers 1996(7)
    Language: Undetermined
    Note: Zugl.: ICES council meeting papers : C
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 5
    In: Deep-sea research. Part 2, Topical studies in oceanography, Amsterdam [u.a.] : Elsevier Science, 1993, 56(2009), 21/22, Seite 1968-1983, 1879-0100
    In: volume:56
    In: year:2009
    In: number:21/22
    In: pages:1968-1983
    Description / Table of Contents: Analysis of the temporal and spatial variability of biological processes and identification of the main variables that drive the dynamic regime of marine ecosystems is complex. Correlation between physical variables and long-term changes in ecosystems has routinely been identified, but the specific mechanisms involved remain often unclear. Reasons for this could be various: the ecosystem can be very sensitive to the seasonal timing of the anomalous physical forcing; the ecosystem can be contemporaneously influenced by many physical variables and the ecosystem can generate intrinsic variability on climate time scales. Marine ecosystems are influenced by a variety of physical factors, e.g., light, temperature, transport, turbulence. Temperature has a fundamental forcing function in biology, with direct influences on rate processes of organisms and on the distribution of mobile species that have preferred temperature ranges. Light and transport also affect the physiology and distribution of marine organisms. Small-scale turbulence determines encounter between larval fish and their prey and additionally influences the probability of successful pursuit and ingestion. The impact of physical forcing variations on biological processes is studied through long-term observations, process studies, laboratory experiments, retrospective analysis of existing data sets and modelling. This manuscript reviews the diversity of physical influences on biological processes, marine organisms and ecosystems and their variety of responses to physical forcing with special emphasis on the dynamics of zooplankton and fish stocks.
    Type of Medium: Online Resource
    Pages: graph. Darst
    ISSN: 1879-0100
    Language: English
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 6
    In: Fisheries research, Amsterdam [u.a.] : Elsevier Science, 1981, 91(2008), 1, Seite 1-14, 0165-7836
    In: volume:91
    In: year:2008
    In: number:1
    In: pages:1-14
    Type of Medium: Online Resource
    Pages: graph. Darst
    ISSN: 0165-7836
    Language: English
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 7
    In: Oceanologia, Sopot : [Verlag nicht ermittelbar], 1971, 50(2008), 2, Seite 205-220, 0078-3234
    In: volume:50
    In: year:2008
    In: number:2
    In: pages:205-220
    Description / Table of Contents: Existing coupled biophysical models for Baltic larval cod drift, growth and survival use idealised constructed mean prey fields of nauplius distributions. These simulations revealed the best feeding conditions for Baltic cod larvae longer than 6 mm. For shorter, first feeding larvae (between 4.5 and 6 mm) pronounced differences in growth and survival were observed, which depend on food availability and to a lesser degree on ambient temperature. We performed runs with an Individual-based Model (IBM) for Baltic cod larvae in order to demonstrate how natural variability in prey abundance influences the survival success of first feeding larvae. In the Baltic, this larval stage lives mainly between 20 and 40 m depth and feeds exclusively on the nauplii of different calanoid copepods (Acartia spp., Pseudocalanus acuspes, Temora longicornis and Centropages hamatus). Prey data obtained from vertically stratified samples in the Bornholm Basin (Baltic Sea) in 2001 and 2002 indicate a strong variability at spatial and temporal scales. We calculated larval survival and growth in relation to natural variation of prey fields, i.e. species-specific nauplius abundance. The results of the model runs yielded larval survival rates from 60 to 100% if the mean size of nauplii species was taken and lower survival if prey consisted of early nauplius stages only.
    Type of Medium: Online Resource
    ISSN: 0078-3234
    Language: English
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Ocean dynamics 39 (1986), S. 35-40 
    ISSN: 1616-7228
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Summary An investigation is described which examines the influence of long-term storage on the salinity of bottled seawater samples in common soft glass bottles. Two experiments were carried out over independent time periods, the first one covering 7 months and the second one 16 months. The results show that long-term storage increases mean salinity and variance. During the first 6 months a rate of change of about 0.0012 in 30 days is observed. After that time the rate of change decreases to about 0.0004 per 30 days. The observed curve is interpreted as desorption of glass components into the seawater sample. Evaporation and the influence of efficient biological activities can be excluded confidently. For the salinity sample bottles used in the physical laboratories in Kiel the results make long-term stored salinity samples inappropriate for accurate in-situ calibration of modern CTD devices. The details of the chemical reactions were not investigated.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 9
    facet.materialart.
    Unknown
    Elsevier
    In:  Deep Sea Research Part I: Oceanographic Research Papers, 40 (11-12). pp. 2167-2177.
    Publication Date: 2018-03-07
    Description: The origin and the spreading of the shallow Mediterranean water core (Ms) in the Iberian basin is discussed with a quasi-synoptic hydrographic data set enhanced by chlorofluoromethane (CFM) measurements. Its characteristic density level is found to be σt = 27.4. Characterized by high temperature and CFM values, Ms enters the Iberian basin in the region of Cape St Vincent between depths of 500–750 dbar. A heat anomaly of 〉11.8 × 109 J m−2 is chosen as the boundary between the presence of Ms and the background field. The core is found in a tongue-like shape as well as in separate isolated eddies of both cyclonic and anticyclonic circulation. Using the optimum multiparameter analysis (Tomczak and Large, 1989, Journal of Geophysical Research, 94, 16141–16149), the North Atlantic Central Water (NACW), which mixes with the Mediterranean outflow to form Ms, turned out to be in the mean 1°C warmer and 0.11 saltier than in regions with minor Mediterranean influence. This points to the Gulf of Cadiz as the origin of Ms, where the Mediterranean oufflows is in contact with NACW of the appropriate characteristics.
    Type: Article , PeerReviewed
    Format: text
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 10
    facet.materialart.
    Unknown
    AGU (American Geophysical Union)
    In:  Journal of Geophysical Research: Oceans, 98 (C6). p. 10155.
    Publication Date: 2018-03-05
    Description: Hydrographic data of temperature, salinity, oxygen, nitrate, phosphate, and silicate at 81 stations with 435 samples on 3 sections between the Azores, the Grand Banks of Newfoundland, and the Bermuda Islands are used to determine the mixing of water masses by optimum multiparameter analysis over the depth range 100–1500 m. The method optimally utilizes all information from our hydrographic data set by solving an overdetermined set of linear mixing equations for all parameters using the method of least squares residuals. It is shown that the method gives quantitative information on the influence of the various water masses of the western North Atlantic. The Gulf Stream and the North Atlantic Current appear as broad bands transporting large amounts of Western North Atlantic Central Water at their warm flank. Western Subarctic Intermediate Water and Shelf Water supplied by the Labrador Current and containing significant amounts of Labrador Current Water are found on their inshore side. The area of the Azores front is found in the vicinity of the Comer Seamounts, where the uniform water mass distribution of the Sargasso Sea changes into a more complex structure that reflects the influence of water masses originating in the Labrador Sea. Small-scale structures, like eddies or Gulf Stream rings, are also detectable by this analysis method. Comparison with dynamic height analysis supports the circulation pattern of the North Atlantic Current as a continuation of the Gulf Stream, and of the southeastward flowing Azores Current originating in the area of the Southeast Newfoundland Rise.
    Type: Article , PeerReviewed
    Format: text
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...