Isabel Palomera

Isabel Palomera
Spanish National Research Council | CSIC · Institute of Marine Sciences

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108
Publications
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Publications

Publications (108)
Article
Variability in body condition and energy storage has important implications for fish recruitment and ecosystem structure. Understanding strategies for energy allocation to maintenance, reproduction and growth is essential to evaluate the state of the fish stocks. In this study, we address the energetics dynamics of the annual cycle of anchovies (En...
Article
Information on the spatial patterns and habitat preferences of marine species is key to understand the functioning of marine ecosystem and to manage and protect marine resources efficiently. However, the study of spatial patterns of marine ecosystems is challenging because they are dynamic environments that can vary seasonally. We analysed the spat...
Article
The recent northward expansion of the round sardinella Sardinella aurita in the Mediterranean Sea has been documented as a consequence of rising sea temperature. At the same time, declines in sardine and anchovy biomass have been observed in the NW Mediterranean Sea, necessitating an assessment of whether the expansion of round sardinella may affec...
Article
Full-text available
Important changes have been observed in recent decades in small pelagic fish (SPF) populations of the NW Mediterranean Sea: Declines in biomass and landings of European anchovy and sardine, and a geographical expansion of round sardinella. These changes have been linked to environmental factors directly influencing annual recruitment and growth. Th...
Article
We evaluated seasonal patterns of biodiversity of the megabenthic non-crustacean invertebrates on soft bottoms of the continental shelf and slope of the Catalan Sea (Balearic Sea, Northwestern Mediterranean). Scientific demersal trawls were carried out between 30 and 400 m during winter and summer of 2013 in 37 and 45 stations respectively. Among a...
Article
Small and medium pelagic fishes play a central role in marine food webs by transferring energy from plankton to top predators. In this study, direct calorimetry was used to analyze the energy density of seven pelagic species collected over four seasons from the western Mediterranean Sea: anchovy Engraulis encrasicolus, sardine Sardina pilchardus, r...
Poster
In the Mediterranean Sea, European sardine (Sardina pilchardus) is an important species in terms of biomass and catches, although recent declines have been observed, in addition to negative changes in body condition. Different hypothesis, such as food limitation or decline in the quality of food, increase of predation, disease or overexploitation h...
Article
Small pelagic fish are among the most ecologically and economically important marine fish species and are characterized by large fluctuations all over the world. In the Mediterranean Sea, low catches and biomass of anchovies and sardines have been described in some areas during the last decade, resulting in important fisheries crises. Therefore, we...
Article
Full-text available
The ommastrephid squid, Illex coindetii, is one of the most abundant cephalopods in the Mediterranean Sea and an important predator in the ecosystem. In the present study, we examined the diet habits of I. coindetii in the north-western Mediterranean Sea by combining two complementary approaches: stomach content and stable isotopic analyses. Specif...
Article
Ecological knowledge of food web interactions within pelagic marine communities is often limited, impairing our capabilities to manage these ecologically and economically important marine fish species. Here we used stable isotope analyses to investigate trophic interactions in the pelagic ecosystem of the northwestern Mediterranean Sea during 2012...
Article
To realistically predict spatial-temporal dynamics of species in marine ecosystems it is essential to consider environmental conditions in conjunction with human activities and food web dynamics. In this study, we used Ecospace, the spatial-temporal dynamic module of Ecopath with Ecosim (EwE) food web model, to drive a spatially explicit marine foo...
Article
To realistically predict spatial-temporal dynamics of species in marine ecosystems it is essential to consider environmental conditions in conjunction with human activities and food web dynamics. In this study, we used Ecospace, the spatial-temporal dynamic module of Ecopath with Ecosim (EwE) food web model, to drive a spatially explicit marine foo...
Article
Full-text available
Thirty years of progress using the Ecopath with Ecosim (EwE) approach in different fields such as ecosystem impacts of fishing and climate change, emergent ecosystem dynamics, ecosystem-based management, and marine conservation and spatial planning were showcased November 2014 at the conference “Ecopath 30 years-modelling dynamic ecosystems: beyond...
Article
Full-text available
In this study, the feeding apparatus (gill rakers, GR) and the diet composition of European sardine Sardina pilchardus populations living in two contrasting environments were compared: the upwelling area off western Iberia and the comparatively less productive region of the north-western Mediterranean Sea. The importance of local adaptations in the...
Article
Full-text available
We show the application of a Spatially-Explicit Individual-Based Model (SEIBM) to understand the recruitment process of European anchovy. The SEIBM is applied to simulate the effects of inter-annual variability in parental population spawning behavior and intensity, and ocean dynamics, on the dispersal of eggs and larvae from the spawning area in t...
Article
In this study, the feeding apparatus (gill rakers, GRs) and the diet composition of European sardine Sardina pilchardus populations living in two contrasting environments were compared: the upwelling area off western Iberia and the comparatively less productive region of the north-western Mediterranean Sea. The importance of local adaptations in th...
Article
We developed an ecological model to characterize the structure and functioning of the marine continental shelf and slope area of the northwestern Mediterranean Sea, from Toulon to Cape La Nao (NWM model), in the early 2000s. The model included previously modeled areas in the NW Mediterranean (the Gulf of Lions and the Southern Catalan Sea) and expa...
Conference Paper
Numerous studies have demonstrated the relationship between the hydrodynamics and the advection, dispersion and recruitment of small pelagic fish. However, the lack of data has often conditioned the use of realistic locations for the model setup and configuration in transport studies. Using the European anchovy in the NW Mediterranean as a case-stu...
Conference Paper
Full-text available
Illex coindetii is an ommastrephid squid distributed through the Mediterranean Sea, Eastern Atlantic (from the south of Britain to Namibia) and the Western Atlantic (Caribbean, Gulf of Mexico and Straits of Florida). It is one of the most abundant squid species in the by-catch of different fisheries in the Mediterranean. In the Western Mediterranea...
Article
Anchovy and sardine in the Mediterranean are known to share the same habitat and, consequently, to interact with one another. These two sympatric pelagic species are planktivorous and consume a wide range of planktonic prey items during all their developmental stages, potentially overlapping their ecological niches, although the feeding interaction...
Article
Full-text available
We assessed the relative importance of different prey types of the European pilchard (European sardine) from the late larval to the adult stage. Two different methodologies for analysing stomach contents were used to describe the trophic dynamics of sardine and the relationship of sardine feeding behaviour with the ontogenetic development of body s...
Article
The study of trophic ecology of marine predators is crucial to better understand the ecological factors that condition their role within marine ecosystems. Here we investigated the trophic habits and position of a Mediterranean endemic predator, the starry ray, Raja asterias. Specifically, we quantified the diet composition of this endemic ray in a...
Article
Full-text available
To date, there are numerous transport simulation studies demonstrating the relevance of the hydrodynamics for the advection, dispersion and recruitment of early stages of marine organisms. However, the lack of data has conditioned the use of realistic locations for the model setup and configuration in transport studies. This work (I) demonstrates t...
Article
European pilchard Sardina pilchardus late larvae were collected in the Gulf of Manfredonia, an important nursery area, during their seasonal inshore occurrence. Thanks to diel cycle sampling and to the wide range of larval lengths (from a minimum of 27 mm to a maximum of 45 mm), both feeding rhythm and ontogenetic changes were analysed. The feeding...
Article
a b s t r a c t The Mediterranean endemic starry ray (Raja asterias) is one of the few demersal skates that are still pres-ent in Mediterranean exploited ecosystems. However, this species has declined with time, its presence in survey data is scarce, and limited information is available about its ecology and the impact of fishing on its populations...
Article
We examined various fishing management options to recover exploited marine resources and ecosystems of the Northern-Central Adriatic Sea. Dynamic simulations were based on a spatial ecological model previously calibrated with time series of data. Scenarios regarding spatial management were evaluated with the establishment of two marine protected ar...
Article
Full-text available
We investigated ontogenetic and seasonal changes in the feeding ecology of 2 small pelagic fish species, the European anchovy Engraulis encrasicolus and the European pilchard Sardina pilchardus in the Gulf of Lions (NW Mediterranean). By analysing the stable isotopes δ13C and δ15N, we determined the seasonal variation in the food sources and in the...
Conference Paper
Elucidating the impact of climatic changes on fish populations can be complicated due to the important number of associated factors that affect the environment and the biology of the species. Also other anthropogenic alterations in the ecosystem, such as overfishing or eutrophication, often entail alterations in the trophic structure of the communi...
Article
Full-text available
Recruitment of European anchovy has been traditionally thought to largely depend on the passive transport and dispersion of eggs and larvae from spawning to nursery areas. Knowledge of the factors influencing the vertical distribution of fish early stages, and consequently influencing the transport, is a crucial issue in fisheries science. The aim...
Conference Paper
Full-text available
Egg and larval transport is defined as the horizontal translocation of a particle in a bidimensional plane from an initial (x1,y1) to a final (x2,y2) position, that is, perpendicular and parallel with the coastline. The vertical axis (z or depth) is ignored in order to simplify the analyses (Pineda et al., 2007). However, this dimension is critical...
Article
The Mediterranean deep sea, being isothermal and longitudinally trophic-graded, is an optimal natural benchmark to test for macro-ecological patterns of species distribution. The relevance of environment−biota interactions on deep-sea megafauna in the Mediterranean Sea, a matter still neglected, is addressed here along longitudinal and bathymetric...
Article
Full-text available
The diel variation in feeding intensity and daily ration of the sardine Sardina pilchardus (Walbaum, 1792) was investigated based on 50 pelagic trawl hauls carried out during the period of thermal stratification (July 2007 and July 2008) and mixing (December 2007 and February 2009) in a coastal area of the North Aegean Sea (eastern Mediterranean)....
Article
Understanding how marine ecosystems are structured and how they function is a scientific challenge. Nowadays, to learn about ecosystem trophic dynamics ecologists use two complementary methodological approximations, mass-balance ecosystem models and isotopic tools. However, despite the wide applications of these methodologies, the comparison and co...
Article
Full-text available
We analyzed data from catch statistics, scientific surveys and results from ecosystem models to assess main changes in marine resources of the North-Central Adriatic Sea (Central Mediterranean) from the mid 1970s to the early 2000s. We then quantified food-web changes using these datasets and trophodynamic indicators. We applied time series trends...
Conference Paper
Las poblaciones de peces pelágicos como las de anchoa y sardina son las más explotadas en el Mediterráneo. Además, al ser especies de vida corta, especialmente afectadas por las fluctuaciones ambientales, es imprescindible profundizar en los aspectos de su biología para establecer una gestión adecuada del recurso. Este trabajo se encuadra en un pro...
Article
This study presents a comparative analysis of protected and exploited Mediterranean Sea food webs using standardized ecological models of two ecosystems: the Central-North Adriatic Sea (highly exploited) and the Miramare Natural Marine Reserve (Northern Adriatic Sea, protected since 1986). Food webs are analysed in terms of structural and functiona...
Conference Paper
This work was carried out in the framework of SARDONE project to assess and compare the ecology of juveniles of Engraulis encrasicolus (L.) in two important fishing areas of the Mediterranean Sea. Although in the Adriatic Sea the mean zooplankton biomass was much higher than in the Gulf of Lions during autumn 2007, the diet of the anchovy juveniles...
Article
The objective of this work was to describe inter- and intra-annual variations in the environmental characteristics of the North-eastern Aegean Sea and to relate these changes to the egg and larval distributions, growth and feeding of larval anchovy (Engraulis encrasicolus). Four cruises, two in July and two in September in 2003 and 2004 were perfor...
Article
Full-text available
The vertical distribution of pelagic fish eggs is an important issue in modeling and fisheries science. Knowledge on the influence of egg-density is a key aspect in IBM's where satisfactory equations to simulate realistic spatial variation are required. The egg-density of European anchovy is poorly known and only some studies on Atlantic provide in...
Article
We analysed changes in the ecological roles of species, trophic structure and ecosystem functioning using four standardized mass-balance models of the South Catalan Sea (North-western Mediterranean). Models represented the ecosystem during the late 1970s, mid 1990s, early 2000s, and a simulated no-fishing scenario. The underlying hypothesis was tha...
Article
Full-text available
We used a process-oriented model (Ecosim) to characterize changes in marine resources in the north-central (NC) Adriatic Sea (Mediterranean) from 1975 to 2002, and to explore the extent to which these changes were driven by trophic interactions, environment and fishing. Fishing efforts and fishing mortalities were used to drive the ecosystem model,...
Article
Full-text available
Otolith growth and the value and properties of the Recent Otolith Growth Index (ROGI) were studied in sea bass (Dicentrarchus labrax L.) larvae that were reared for the first month of life with four different feeding regimes: fed, non-fed, late-feeding and late two-day fast. A marking experiment using alizarin complexone was previously carried out...
Chapter
Full-text available
The assessment and management of small pelagic fish (SPF) stocks is particularly difficult and uncertain because their short life expectancy, characteristic aggregative behavior, rapid response to climate and environmental signals and large and variable natural mortality make them less tractable through traditional population dynamic models and ass...
Data
Variation of L index from nominal value (open circle) as resulting from changes in input parameters (X = TLc, PPR, PP and TE) around their nominal value. Each curve results from sensitivity analyses on one single parameter indicated between parentheses, L(X). (0.04 MB DOC)
Data
Assessment of ecosystem overfishing for Open Sea (FAO areas) for the period 2000–2004 including higher estimates of IUU catches (results follow the ones presented in Table S1). (0.03 MB DOC)
Data
Results of global sensitivity on L index obtained by randomly choosing the four input parameters from normal distributions (μ = nominal values, SD = 10% for all but 5% for TLc). White and red circles represent median and mean values, respectively. (1.12 MB DOC)
Data
Global assessment of ecosystem overfishing for Large Marine Ecosystems (LME) and Open Sea (FAO areas) for the period 2000–2004. (0.07 MB DOC)
Data
Global assessment of ecosystem overfishing for Large Marine Ecosystems (LME) and Open Sea (FAO areas) for the period 1990–1999. (0.05 MB DOC)
Data
Global assessment of ecosystem overfishing for Large Marine Ecosystems (LME) and Open Sea (FAO areas) for the period 1970–1979. (0.06 MB DOC)
Data
Global assessment of ecosystem overfishing for Large Marine Ecosystems (LME) and Open Sea (FAO areas) for the period 1950–1959. (0.05 MB DOC)
Article
An ecosystem model representing the continental shelf and upper slope of the South Catalan Sea (NW Mediterranean) is calibrated and fitted to the available time series data from 1978 to 2003. We use a process-oriented model to explore the extent to which changes in marine resources and the ecosystem were driven by trophic interactions, environmenta...
Article
Full-text available
The spatial distribution, biomass and size structure of key mesozooplankton species and micronekton in the Bransfield Strait (Antarctica) are described in relation to environmental variables during the austral summer 2001. Stratified (BIONESS) biological sampling at five depth-ranges and CTD casts were performed at 40 stations, including a cross-St...
Article
Full-text available
We explored the potential ecosystem effects of improved selectivity in the South Catalan Sea demersal trawl fishery. A calibrated food web model representing current conditions of the ecosystem and selectivity data from recent fishing experiments were used to perform temporal dynamic simulations. This enabled the evaluation of direct and indirect i...
Article
Full-text available
23 pages. Exploited ecosystems are characterised by exports of secondary production from each fished trophic level that reduce the energy available for upper levels at the ecosystem scale, thus impinging on overall secondary production. Depletion in secondary production is proposed here as a proxy for quantifying the ecosystem effects of fishing. T...
Article
Full-text available
Fisheries catches represent a net export of mass and energy that can no longer be used by trophic levels higher than those fished. Thus, exploitation implies a depletion of secondary production of higher trophic levels (here the production of mass and energy by herbivores and carnivores in the ecosystem) due to the removal of prey. The depletion of...
Article
In the NW Mediterranean Sea, anchovy (Engraulis encrasicolus) and sardine (Sardina pilchardus) are the most important small pelagic fish in terms of biomass and commercial interest. Round sardinella (Sardinella aurita) and Sprat (Sprattus sprattus) are also present in this region. This paper provides a general insight into the ecology of these spec...
Article
A trophic mass-balance model was developed to characterise the food web structure and functioning of the Northern and Central Adriatic Sea and to quantify the ecosystem impacts of fishing during the 1990s. Forty functional groups were described, including target and non-target fish and invertebrate groups, and three detritus groups (natural detritu...
Article
The Mediterranean is globally considered an oligotrophic sea. However, there are some places or certain seasons in which mechanisms that enhance fertility may occur. These mechanisms and related processes are especially relevant when they take place during the period of larval development. This study analyzes how environmental conditions occurring...
Article
The Gulf of Lions is one of the main anchovy (Engraulis encrasicolus) spawning areas in the NW Mediterranean. During the spring, low-salinity surface water from the outflow of the Rhône is advected by the shelf-slope current along the continental slope off the Catalan coast. In June 2000, a Lagrangian experiment tracking these low-salinity surface...
Article
The NW Mediterranean has a number of structural features in common with upwelling ecosystems. Therefore, an ecological model representing a NW Mediterranean exploited ecosystem was standardized and compared with four previously standardized models from coastal upwelling ecosystems: the Northern and Southern Humboldt (Chile and Peru upwelling system...
Article
Eggs and larvae of anchovy were obtained from plankton collections made along the Catalan coast (north-western Mediterranean) from 1983 to 1985 in order to determine spawning seasons and areas and other aspects of its life history. Previous studies have shown the existence of two main spawning areas, to the north and south of the Catalan coast, res...
Article
Relationships between environmental factors and the growth and condition of pilchard Sardina pilchardus (Walbaum) larvae were studied in November 1998 in the northwestern Mediterranean (NWM). Long-term growth of fish was assessed using otolith analysis and condition was assessed through histological and biochemical (RNA/DNA) indices. These measurem...