Is the Gulf of Cadiz ready for the ecosystem approach? A perspective from the southernmost European Atlantic regional sea

This study considers the major milestones in history, current situation and prospects of developing an ecosystem approach to management in the Gulf of Cadiz ecosystem. This particular socio-ecosystem is characterised by a clear focal ecosystem component –the role of the estuary of the Guadalquivir River as a nursery area– that have an influence on the marine ecosystem and at the same time concentrates a great number of sectoral human activities. This nursery role particularly affects the anchovy fishery, which is the most economically and culturally important fishery in the region. As a transition zone between river and marine environments, estuaries are particularly sensitive to human activities, either developed directly at the aquatic environment and its surroundings or far upstream within its catchment area. The particularities of the Guadalquivir socio-ecosystem, with an area of influence that extend as far as the city of Seville, require the consideration of multiple sectors and corresponding conflicting interests. These comprise the shipping and touristic sectors, the agriculture and aquaculture industries, or the fisheries and conservation interests. Specifically, the aim of this work is to give an overview of the main components, actors, and challenges faced by this socio-ecological system. This includes: (1) describing the ecological characteristics and focal mechanisms, (2) the legislative framework and the responsible institutional bodies, (3) the involved sectors and their corresponding pressures, (4) identifying the institutional arrangements that could be potentially used to harmonize those conflicting interests and finally (5) a diagnose of the problems encountered when conflict has arisen that has so far blocked the development of an ecosystem approach in the region

the Gulf of Cadiz

CREAM projec

Spatio-temporal variability of the North Sea cod recruitment in relation to temperature and zooplankton

The North Sea cod (Gadus morhua, L.) stock has continuously declined over the past four decades linked with overfishing and climate change. Changes in stock structure due to overfishing have made the stock largely dependent on its recruitment success, which greatly relies on environmental conditions. Here we focus on the spatio-temporal variability of cod recruitment in an effort to detect changes during the critical early life stages. Using International Bottom Trawl Survey (IBTS) data from 1974 to 2011, a major spatio-temporal change in the distribution of cod recruits was identified in the late 1990s, characterized by a pronounced decrease in the central and southeastern North Sea stock. Other minor spatial changes were also recorded in the mid-1980s and early 1990s. We tested whether the observed changes in recruits distribution could be related with direct (i.e. temperature) and/or indirect (i.e. changes in the quantity and quality of zooplankton prey) effects of climate variability. The analyses were based on spatially-resolved time series, i.e. sea surface temperature (SST) from the Hadley Center and zooplankton records from the Continuous Plankton Recorder Survey. We showed that spring SST increase was the main driver for the most recent decrease in cod recruitment. The late 1990s were also characterized by relatively low total zooplankton biomass, particularly of energy-rich zooplankton such as the copepod Calanus finmarchicus , which have further contributed to the decline of North Sea cod recruitment. Long-term spatially- resolved observations were used to produce regional distribution models that could further be used to predict the abundance of North Sea cod recruits based on temperature and zooplankton food availability.Publicado

El ecosistema del golfo de Cádiz se recupera gracias a la regulación de la pesca

Científicos del Instituto Español de Oceanografía (IEO) han publicado un trabajo en el que analizan la evolución de las poblaciones marinas del golfo de Cádiz durante los últimos 20 años y los resultados revelan la efectividad de las medidas de regulación de la pesca para revertir la degradación de los ecosistemas y cómo otras medidas políticas puntuales –como los acuerdos de pesca con Marruecos– pueden afectar también a su estado de conservación

Influencia de la variabilidad del medio marino en los recursos pesqueros. Enfoque integral de ecosistema

FREMSS, IE