Cantabrian Sea ecosystem model and fishery
resources management
Francisco Sânchez, Ignacio Olaso
Instituto Espanol de Oceanografia, Apdo 240, 39080 Santander, Espana
f.sanchez@st.ieo.es
Abstract
The Ciantabrian Sea ecosjrstem is described using a mass-balance model of
trophic interactions, in order to know the impacts of the different fisheries that operate in this area. Kstimation cof trophic level of fisheries,
transfer efficiency between trophic levels and mixed trophic impact analysis considering the fishety both as an impacting and impacted component are included. Also, we explore the potential relevance of simulating the effect of different fishing regimes on the ecoststem flow
structure using Ecosim. Finally, Ecospace was used as an exploratory
tool for the analysis of trophic relationships in the space and for the
evaluation of the effect of some management options.
Resumen
Se describe el ecosistema del Mar Cantábrico usando un modelo de balance
de masas con el objetivo de conocer los impactos de las pesquerias que
actían en la zona. Se incluyen estimaciones del nivel trôfico de las
pesquerias, la eficiencia del transporte de biomasa entre los distintos
niveles trôficos y el impacto trôfico mixto considerando a la pesqueria
tanto como su componente impactante como impactado. También se
explora el potencial de la simulaciôn de diferentes esfuerzos de pesca
sobre la estructura del flujo de biomasa en el ecosistema con Ficosim.
Por ûltimo, se emplea Ecospace como una herramienta exploratoria en
el anâlisis de las relaciones trôficas en el espacio y para evaluar el efecto
pnjducido por algunas medidas de gestiôn.
Introduction
Due to the particular situation of the Cantabrian Sea, it is possible to
find typical temperate water species together with others of northem
origin or subtropical species from the south and consequently high diversity indices exist. It is the winter spawning area for some species, such
as hake, megrims, red-sea bream and horse mackerel, and the feeding
area for others, e.g. anchot 7 )’ and tuna. Some other species remain outside of the ecosvstem during different seasons due to their migratoty
habits (e.g. mackerel, blue whiting). Also, fishing is an important economic resource in the Cantabrian Sea (approximately 200 000 tons per
year), where a large commercial fleet exists. Trawlers fish on the muddy
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resources management
Francisco Sânchez, Ignacio Olaso
Instituto Espanol de Oceanografia, Apdo 240, 39080 Santander, Espana
f.sanchez@st.ieo.es
Abstract
The Ciantabrian Sea ecosjrstem is described using a mass-balance model of
trophic interactions, in order to know the impacts of the different fisheries that operate in this area. Kstimation cof trophic level of fisheries,
transfer efficiency between trophic levels and mixed trophic impact analysis considering the fishety both as an impacting and impacted component are included. Also, we explore the potential relevance of simulating the effect of different fishing regimes on the ecoststem flow
structure using Ecosim. Finally, Ecospace was used as an exploratory
tool for the analysis of trophic relationships in the space and for the
evaluation of the effect of some management options.
Resumen
Se describe el ecosistema del Mar Cantábrico usando un modelo de balance
de masas con el objetivo de conocer los impactos de las pesquerias que
actían en la zona. Se incluyen estimaciones del nivel trôfico de las
pesquerias, la eficiencia del transporte de biomasa entre los distintos
niveles trôficos y el impacto trôfico mixto considerando a la pesqueria
tanto como su componente impactante como impactado. También se
explora el potencial de la simulaciôn de diferentes esfuerzos de pesca
sobre la estructura del flujo de biomasa en el ecosistema con Ficosim.
Por ûltimo, se emplea Ecospace como una herramienta exploratoria en
el anâlisis de las relaciones trôficas en el espacio y para evaluar el efecto
pnjducido por algunas medidas de gestiôn.
Introduction
Due to the particular situation of the Cantabrian Sea, it is possible to
find typical temperate water species together with others of northem
origin or subtropical species from the south and consequently high diversity indices exist. It is the winter spawning area for some species, such
as hake, megrims, red-sea bream and horse mackerel, and the feeding
area for others, e.g. anchot 7 )’ and tuna. Some other species remain outside of the ecosvstem during different seasons due to their migratoty
habits (e.g. mackerel, blue whiting). Also, fishing is an important economic resource in the Cantabrian Sea (approximately 200 000 tons per
year), where a large commercial fleet exists. Trawlers fish on the muddy
187