pdf bromatologia

ANALES DE BIOLOGÍA, 15 (Biología Ambiental, 4), (1988) 1989: 191-208
SECRETARIADO DE PUBLICACIONES - UNlVERSlDAD DE MURCIA

ESTRUCTURA Y DINÁMICA DE LA COMUNIDAD INFRALITORAL DE CODIUM
VERMILARA (OLIVI) DELLE CHIAJE DE LA COSTA BR A V A (MEDITERRÁNEO
OCCIDENTAL).
E. Ballesteros*
Recibido: 18 marzo 1988
Aceptado: 7 noviembre 1988
SUMMARY
Structure and dynamics of Codium vermilaracommunity in the Costa Brava (Western Meditemanan).
Codium vermilara community occurs in rocky bottoms around 8-20 meters depth in some places of the
Catalan Coast (Northwestern Mediterranean). Species composition is dominated by sciaphilic algae such as
Codium vermilara, Halopreris Jilicina and Sphaerococcus coronopifolius, Encrusting algae (e.g. Mesophyllum
lichenoides, Neogoniolirhon mamillosum?)cover al1 the substrate and represent a high percentage of the whole
biomass. Turf-algae are also very abundant and thallus of Codium vermilara are entirely covered by epiphytes
in spring. Biomass ranges between 1.500 and 2.000 g dwt m - Z (including calcareous algae) and percentage
coverage ranges between 180 and 410%. Species richness is extraordinarily high (up to 129 species in 1.024
cm2).Species diversity (Shannon's index) ranges between 1.6 and 2.7 bits (calculated from biomass values) or
between 2.8 and 4.3 bits (calculated from coverage values). Pattern diversity is relatively high, so that areas of
600 cm 2 are recommended in order to pick up representative samples of this community.
Community dynamics can be included in the model described by BALLESTEROS (1984) forMediterranean
phytobenthic communities. Production phase occurs in spring-summer, while diversification phase occurs in
autumn-winter. Production of Codium vermilara seems to be mainly limited by light since period of maximum
growth occurs in spnng and summer. Nevertheless, nutrient availability seems to play an important role in
production cycle of this species, slightly displacing production tospnng, when irradiance has not reached its
maximum values but nutrient concentration in seawater is still detectable. Mean annual production of Codium
vermilara ranges between 0.15 and 0.30 g C m-2 day- ',and community production ranges between 0.3 and 0.4
g C m-2 day-l that represents an amount of organic matter higher than that produced by phytoplankton. In
comparison with other Mediterraneancommunities these values are lower than those estimated from other
infralittoral communities, but higher than those estimated from circalittoral, strongly light-limited, communities.
Key words: Community structure, Community dynamics, Phytobenthos, Codium, Western Mediterra-

nean.
RESUMEN

Se analiza la composición específica, la estructura y la dinámica de la comunidad de Codium vermilarapropia de los fondos rocosos de la Costa Brava situados entre los 8 y los 20 metros de profundidad. Esta
comunidad, dominada por especies esciáfilas es extraordinarimante rica en especies, posee una elevada diversidad y el motivo estructural se alcanza para superficies cercanas a los 600 cm2. La variación del recubrimiento
a lo largo del año permite describir la dinámica de la comunidad. Estase ajusta al modelo general descrito para
las comunidades bentónicas del Mediterráneo Occidental. La fase de producción tiene lugar en primavera-verano y la fase de diversificación ocurre en otoño-invierno, como corresponde a una comunidad de tránsito
entre las zonas infralitoral y circalitoral. El crecimiento de Codium vermilara está gobernado por la disponibilidad de luz y nutrientes aunque lairradiancia parece ser el factor principal. La producción anual media de

*

Centre d'Estudis Avancats. C. Sta. Bhrbara s/n. 17300 Blanes. Girona. Spain.

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E.

BALLESTEROS

Codium vermilara se ha estimado en 0.15-0.30 g C m-2 día- l y la producción global de la comunidad en 0.3-0.4
g C m-2 día- l , valores inferiores a la producción de otras comunidades infralitorales pero...