589 research outputs found
Analysis of the Variations in the Spacial Distribution and Spawning of the Greenland Halibut In Divisions 3LMN (1990-93)
In this paper the geographic, bathymetric and seasonal
distribution of the adult Greenland halibut stock exploited in
the Flemish Pass area (Div. 3LMN) is analysed for the period 1990
- 1993 using data collected by observers on board the commercial
fleet. A southward shift of the fishing area took place and adult
fish and spawning activity were recorded in unsual areas. The
main areas and seasons of spawning are described. A peak time
for spawning has not been found and spawning females appeared
evenly represented at any time of the day
Feeding Cycles of Greenland Halibut (Reinhardtius hippoglossoides) in the Flemish Pass Area in Relation to Catch Rates (1991-92)
The seasonal cycle in feeding activity of Greenland halibut
shows a maximum in autumn in depths between 700 - 900 m. In deeper
waters no seasonality appears at all. A 24-hour cycle in feeding
activity is observed which is length related, with a daytime
(6-12 hour interval) maximum in smaller fish (<60 cm) and at
both sunset and night (18-24 hour and 0-6 hour intervals) in the
largest fish (<80 cm). The intermediate length class (60-80 cm)
shows a minimum in feeding activity in the afternoon (12-18 h) and
in general a maximum in the interval 6-12 h, but in this group
significant feeding activity occurs also at night.
Catch rates decrease in autumn and reach a maximum in winter.
In winter, increased catchs occurs mainly at night (0-6 h
interval) and are based mainly in the smallest length class
(<60 cm), which feeds least during this time interval. An inverse
relationship between feeding intensity and catch rates is been
observed
Standardized CPUE Indices for Greenland Halibut and American Plaice in NAFO Divisions 3LMNO Based on Spanish Commercial Catch Rates
Standardized cpue series using a Generalized Linear Model for Greenland halibut and American plaice in
Division 3LMNO, based on catch and effort data from the Spanish trawl fleet since 1990 at depth intervals are
presented. In the case of the Greenland halibut series, the largest proportion of the variance (45%) is explained by
the factor ‘depth’, while in the American plaice on it is the factor ‘vessel’ (51%). The general trend observed in the
Greenland halibut standardized CPUE in all divisions is a sharp increase in the indices from about 600 m, attaining
maximum values between 900-1 000 m, and then decreasing at depths beyond 1 200 m. American plaice CPUE
values at depths less than 500 m are very small in all divisions. The American plaice cpue series show two peaks
one between 100-200 m. and the other between 400-500 m, decreasing sharply thereafter. The larger values in this
species are observed in Div. 3L and 3N, while very small ones are in Div. 3M at any depth
Sexual Maturity and Spawning of the Greenland Halibut (Reinhardtius hippoglossoides) From Flemish Pass Area
10 páginas, 4 figuras, 3 tablas.-- Scientific Council MeetingPeer reviewe
ab inito local vibrational modes of light impurities in silicon
We have developed a formulation of density functional perturbation theory for
the calculation of vibrational frequencies in molecules and solids, which uses
numerical atomic orbitals as a basis set for the electronic states. The
(harmonic) dynamical matrix is extracted directly from the first order change
in the density matrix with respect to infinitesimal atomic displacements from
the equilibrium configuration. We have applied this method to study the
vibrational properties of a number of hydrogen-related complexes and light
impurities in silicon. The diagonalization of the dynamical matrix provides the
vibrational modes and frequencies, including the local vibrational modes (LVMs)
associated with the defects. In addition to tests on simple molecules, results
for interstitial hydrogen, hydrogen dimers, vacancy-hydrogen and
self-interstitial-hydrogen complexes, the boron-hydrogen pair, substitutional
C, and several O-related defects in c-Si are presented. The average error
relative to experiment for the aprox.60 predicted LVMs is about 2% with most
highly harmonic modes being extremely close and the more anharmonic ones within
5-6% of the measured values.Comment: 18 pages, 1 figur
Sexual Maturity and Spawning of the Greenland Halibut (Reinhardtius hippoglossoides) From Flemish Pass Area
10 páginas, 4 figuras, 3 tablas.-- Scientific Council MeetingPeer reviewe
Non-traditional resources: skate fishery and survey results in Division 3NO
Since 1993 a significant increase in the skate catches from the Spanish trawlers have been
reported (Duran et al. 1996; Junquera et al. 1997). It was interpreted as a shift in the fishing strategy
towards the exploitation of non-regulated species. Important skate by-catches are often taken in the
Greenland halibut fishery, but at present a directed, though temporary, fishery has also been established.
In this paper a review of the available information on this subject is presented
Histological Assessment of Sexual Maturity of the Flemish Cap Cod (Division 3M) in 1995
6 páginas, 5 tablas, 2 fisguras.-- Scientific Council Meetin
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