Universidade da Coruña. UDCDspace
(405 recursos)
UDCDspace é o repositorio dixital da Universidade da Coruña, un sistema que proporciona de xeito estable e seguro a preservación de documentos dixitais produto da actividade científica e institucional da UDC, e facilita a súa accesibilidade en Internet.
Mostrando recursos 1 - 13 de 13
1.
Population modelling of European shags ("Phalacrocorax aristotelis")
at their southern limit: conservation implications - Velando Rodríguez, Alberto; Freire Botana, Juan Manuel
The European shag ("Phalacrocorax aristotelis") population at Cíes Islands (the most important breeding area in its southern limit)
increased rapidly from 1986 to 1992, and afterwards the population suffered a slight decline. This study analyzed population data
obtained from ringing recoveries and reproductive monitoring between 1993 and 1997. The reproductive success was highly variable
and associated with adverse weather events. Adult survival rate was very low compared with other colonies, probably due to high
accidental capture in gill-nets. In recent years, the fishing effort with gill-nets increased in the study area. Sensitivity analysis of
parameters showed that the population is more affected by changes in...
2.
Megabenthic decapod crustacean assemblages
on the Galician continental shelf and upper slope (north-west Spain) - Fariña Pérez, Antonio Celso; Freire Botana, Juan Manuel; González Gurriarán, Eduardo
The structure of megabenthic decapod crustacean
assemblages on the Galician (north-west Spain)
continental shelf (100 to 200 depth) and upper slope (200
to 500 m) was analyzed based on surveys carried out in
autumn and spring, from 1980 to 1987. Forty species
belonging to 19 families were caught. The portunid crab
"Polybius henslowii", a species with pelagic phases, was the
most abundant species, but displayed strong spatial and
temporal fluctuations. Other dominant species were the
Norway lobster "Nephrops norvegicus", the portunid "Liocarcinus
depurator", the galatheids "Munida intermedia" and
"M. sarsi", and the shrimps "Solenocera membranacea",
"Plesionika heterocarpus", "Pasiphaea sivado" and "Dichelopandalus
bonnieri". Total abundance and biomass (average
values excluding Polybius henslowii = 255 individuals
and...
3.
Information-theoretic approach for selection
of spatial and temporal models of community organization - Godínez Domínguez, Enrique; Freire Botana, Juan Manuel
The literature on the ecology of marine assemblages includes frequent examples of data
analysis with no well-defined alternative hypotheses for the definition of environmental variables
(independent matrix for multivariate methods). Alternative models, whereby spatial or temporal
patterns are investigated, should be explicitly assumed. We present a parsimonious procedure for
model selection in multivariate data combined with canonical correspondence analysis to determine
the measure of explained variance for each tested model, using Akaikes information criterion (AIC)
for model selection. The AIC procedure is an effective tool for model selection and, in contrast to
other conventional procedures that use only 1 implicit model and ignore other community patterns, it
provides...
4.
New approaches to the behavioural ecology of decapod crustaceans
using telemetry and electronic tags - Freire Botana, Juan Manuel; González Gurriarán, Eduardo
Decapod crustaceans have complex life histories and behaviour in aspects such as foraging, mating and reproduction,
moulting and growth, habitat selection and migration. New technologies have enabled us to use an individual,
field-based approach to analyze these problems, although they have been less developed in decapods than in marine
vertebrates. These new possibilities are discussed here mainly from a biological point of view. There is a brief
review of previous applications of telemetry to analyze habitat selection, foraging behaviour, energetics, moulting
site selection and migrations in decapods, and two case studies are discussed in more detail. The first one refers to
the study of differences in...
6.
Management strategies for sustainable invertebrate fisheries in coastal
ecosystems of Galicia (NW Spain) - Freire Botana, Juan Manuel; Bernárdez Martí, Cristina; Corgos López-Prado, Antonio; Fernández Rodríguez, Luis José; González Gurriarán, Eduardo; Sampedro Pastor, María Paz; Verísimo Amor, Patricia
Artisanal coastal invertebrate fisheries in Galicia are socio-economically important and ecologically relevant. Their
management, however, has been based on models of fish population dynamics appropriate for highly mobile demersal
or pelagic resources and for industrial fisheries. These management systems focus on regulating fishing effort,
but in coastal ecosystems activities that change or destruct key habitats may have a greater effect on population
abundance than does fishing mortality. The Golfo Artabro was analysed as a representative example of a coastal
ecosystem in Galicia, and the spider crab "Maja squinado" used as a model of an exploited coastal invertebrate,
for which shallow coastal areas are key habitats for...
7.
Socioeconomic and biological causes of management failures in
European artisanal fisheries: the case of Galicia (NW Spain) - Freire Botana, Juan Manuel; García Allut, Antonio
Coastal ecosystems and artisanal fisheries show a great complexity due to the high number of human factors that infuence their
functioning and to the number of components involved in the fishing activity. Moreover, a great number of stocks exploited by coastal
artisanal fisheries are invertebrates with a strong and persistent spatial structure and a population dynamics that do not fit the finfish
models. The present state of the artisanal coastal fisheries in Galicia (NW Spain) is analyzed, presenting di!erent symptoms of
a general state of overexploitation derived from the mismatch between management (derived from models designed for industrial
finfisheries) and the biological and socioeconomic context....
9.
Crustacean fisheries - Tully, Oliver; Freire Botana, Juan Manuel; Addison, Julian
Proceedings of the Conference on Life History Assessment and Management of Crustaceans, La Coruna, Galicia, Spain, 811 October 2001
10.
Development and perspectives for community-based
management of the goose barnacle ("Pollicipes pollicipes") fisheries in Galicia (NW Spain) - Molares Vila, José; Freire Botana, Juan Manuel
The goose barnacle, "Pollicipes pollicipes", is an intertidal cirripede that lives attached to rocks on very exposed shores, forming
dense aggregations. It occurs in the northeast Atlantic (from 48 to 14?N). Commercial fisheries have been developed in several
countries, but except for a short-lived local consumption, most of the production is traded in the Spanish market, where the
price can reach ?80/kg in first-sale auctions. This species shows a strong spatial structure, constituting metapopulations with
local adult populations sharing a common larval pool. Advection of larvae depends largely of oceanographic conditions that
govern larval transport and survival. In Galicia (NW Spain), the regional government regulations...
12.
Plankton biomass and larval fish abundance prior to and
during the El Niño period of 19971998 along the central Pacific coast of México - Franco Gordo, María Carmen; Godínez Domínguez, Enrique; Filonov, Anatoliy E.; Tereshchenko, Irina E.; Freire Botana, Juan Manuel
The temporal and spatial distributions of zooplankton biomass and larval fish recorded during 27 months (December
1995December 1998) off the Pacific coast of central México are analyzed. A total of 316 samples were obtained by surface
(from 4068 to 0 m) oblique hauls at 12 sampling sites using a Bongo net. Two well-defined periods were observed: a
pre-ENSO period (December 1995march 1997) and an ENSO event (July 1997September 1998) characterized by
impoverishment of the pelagic habitat. The highest biomass concentrations occurred at coastal stations during the
pre-ENSO period. During the El Nino period no spatial patterns were found in coastal waters. The months with highest
biomass...
13.
La pesca artesanal gallega y el problema de la comercialización : ¿"Lonxanet.com" como una alternativa? - García Allut, Antonio
La pesca artesanal en Galicia tiene una enorme importancia social, económica y
cultural. No obstante, en ella se dan una serie de problemáticas de carácter estructural
que la hacen vulnerable. La situación de la comercialización de los productos pesqueros
de la pesca artesanal agrava los problemas anteriores desestructurando al sector,
perjudicando a los pescadores y a la viabilidad futura de sus órganos de gestión
(Cofradías). En esta ponencia se presenta una solución que hasta la fecha ha corregido y
mejorado este estado de cosas mediante la puesta en marcha de una iniciativa
empresarial pensada para minimizar estos problemas. Esta iniciativa se llama Lonxanet
y en la que seis...
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