Fidel Echevarría

Fidel Echevarría
Universidad de Cádiz | UCA · Department of Biology

PhD

About

82
Publications
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5,122
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Publications

Publications (82)
Article
Full-text available
The Strait of Gibraltar (SG) is the only connection of the Mediterranean Sea with the global circulation. The SG is an outstanding marine region to explore physical-biological coupling of pelagic communities due to its hydrodynamic complexity, including strong tidal forcing and marked spatial gradients and fronts. The authors have unravelled the ro...
Article
Full-text available
The temporal evolution of the physical and biogeochemical properties of the Atlantic Jet (AJ) along the first ∼ 75 m of the water column during a 4-day journey was analysed by following the trajectory of a drifter dragged by the jet from the Strait of Gibraltar towards the Alborán Sea. Three stages were differentiated based on the evolution of seve...
Article
Full-text available
The surge of research on marine litter is generating important information on its inputs, distribution and impacts, but data on the nature and origin of the litter remain scattered. Here, we harmonize worldwide litter-type inventories across seven major aquatic environments and find that a set of plastic items from take-out food and beverages large...
Article
Full-text available
The biological pump transports organic carbon produced by photosynthesis to the meso-and bathypelagic zones, the latter removing carbon from exchanging with the atmosphere over centennial time scales. Organisms living in both zones are supported by a passive flux of particles, and carbon transported to the deep-sea through vertical zooplankton migr...
Article
Characterisation of the colour is often included in studies on plastic pollution. However, the comparability and relevance of this information is limited by methodology or observer subjectivity. Based on the analysis of thousands of floating plastic fragments from a global collection, here we propose a systematic semi-automatic method to analyse co...
Article
Full-text available
Polyunsaturated aldehydes (PUAs) are bioactive molecules suggested as chemical defenses and infochemicals. In marine coastal habitats, diatoms reach high PUA production levels during bloom episodes. Two fractions of PUA can usually be analyzed: pPUA obtained via artificial breakage of collected phytoplankton cells and dissolved PUA already released...
Article
Full-text available
Sustained observations are required to determine the marine plastic debris mass balance and to support effective policy for planning remedial action. However, observations currently remain scarce at the global scale. A satellite remote sensing system could make a substantial contribution to tackling this problem. Here, we make initial steps towards...
Presentation
Full-text available
Los aldehídos poliinsaturados (PUAs) son compuestos orgánicos volátiles derivados de ácidos grasos poliinsaturados, producidos y liberados al medio marino por diferentes grupos fitoplanctónicos. Experimentalmente se han propuesto diferentes funciones biológicas de dichos compuestos, como de defensa química frente a depredadores (Caldwell, 2009), o...
Article
Full-text available
Cape Trafalgar has been highlighted as a hotspot of high chlorophyll concentrations, as well as a source of biomass for the Alborán Sea. It is located in an unique geographical framework between the Gulf of Cádiz (GoC), which is dominated by long-term seasonal variability, and the Strait of Gibraltar, which is mainly governed by short-term tidal va...
Article
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The subtropical ocean gyres are recognized as great marine accummulation zones of floating plastic debris; however, the possibility of plastic accumulation at polar latitudes has been overlooked because of the lack of nearby pollution sources. In the present study, the Arctic Ocean was extensively sampled for floating plastic debris from the Tara O...
Poster
Full-text available
The Alborán sea is a highly dynamic area connecting the Strait of Gibraltar with the rest of the western basin of the Mediterranean Sea. It is an area characterized by mesoscale processes that strongly affect several biological processes and, therefore, the physiological state of the phytoplanktonic assemblage. The aim of this research is to analyz...
Article
Full-text available
We have supplemented available, concurrent measurements of fresh weight (W, g) and body carbon (C, g) (46 individuals, 14 species) and nitrogen (N, g) (11individuals, 9 species) of marine gelatinous animals with data obtained during the global ocean MALASPINA 2010 expedition (totalling 267 individuals and 33 species for the W versus C data; totalli...
Article
Full-text available
There is a rising concern regarding the accumulation of floating plastic debris in the open ocean. However, the magnitude and the fate of this pollution are still open questions. Using data from the Malaspina 2010 circumnavigation, regional surveys, and previously published reports, we show a worldwide distribution of plastic on the surface of the...
Article
Full-text available
Diatoms, a major component of the large-sized phytoplankton, are able to produce and release polyunsaturated aldehydes after cell disruption (potential PUAs or pPUA). These organisms are dominant in the large phytoplankton fraction (>10 µm) in the Strait of Gibraltar, the only connection between the Mediterranean Sea and the Atlantic Ocean. In this...
Article
Full-text available
With a current estimate of ~1,000 million tons, mesopelagic fishes likely dominate the world total fishes biomass. However, recent acoustic observations show that mesopelagic fishes biomass could be significantly larger than the current estimate. Here we combine modelling and a sensitivity analysis of the acoustic observations from the Malaspina 20...
Article
Full-text available
Polyunsaturated aldehydes (PUAs) are organic compounds mainly produced by diatoms, after cell wounding. These compounds are increasingly reported as teratogenic for species of grazers and deleterious for phytoplanktonic species, but there is still scarce information regarding concentration ranges and the composition of PUAs in the open ocean. In th...
Article
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This article presents a detailed analysis of the sub-mesoscale transport processes in the Strait of Gibraltar. The interest is focussed on the Camarinal Sill region, and special attention is paid to the across-strait transport processes, the divergences and convergences in the central zone, and the small-scale circulation patterns along the norther...
Article
Full-text available
Physical processes forced by tidal dynamics, such as bores and internal waves, have a high influence on biological patterns in the main channel of the Strait of Gibraltar. To analyse this connection in the case of photosynthetic processes, a set of high resolution profiles of physical (temperature, salinity, and light) and chemical (nutrients and c...
Article
Full-text available
Mesozooplankton organisms (>250 mu m) were sampled at two stations (inner and outer Bay) in the Bay of Cadiz between May and July 2008. Samples were analysed by means of a semi-automated technique in order to give a preliminary view of the mesoozooplankton community structure in the Bay, based on taxonomic diversity and biomass distribution among s...
Article
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We analyzed the effect of physical forcing on zooplankton biomass distribution in the Strait of Gibraltar as a function of tidal phase. A set of 5 Longhurst-Hardy-Plankton-Recorder (LHPR) casts were made along the main channel of the Strait during different phases of the tidal cycle to determine how the hydrological processes taking place in the st...
Article
Full-text available
de la Torriente, A., Quiñones, R. A., Miranda-Urbina, D. A., and Echevarría, F. 2010. South American sea lion and spiny dogfish predation on artisanal catches of southern hake in fjords of Chilean Patagonia. – ICES Journal of Marine Science, 67: 294–303. The South American sea lion (Otaria flavescens) is a pinniped known to interact with fisheries,...
Conference Paper
In this presentation we review the contribution of Spain to GLOBEC during the lifetime of this program. Around 50 individual projects funded by national, regional or European programs have fed the activities performed. It has been also important the effort made by the IEO (Spanish Institute of Oceanography) maintaining a monitoring program at sever...
Book
The Strait of Gibraltar is the unique and narrow connection between the Mediterranean basin and the open Atlantic Ocean. One of the main features of this place is the strong topographic constriction that happens both in the horizontal and vertical dimension in conjunction with the presence of a two-layered counter-current circulation and strong ine...
Chapter
The Strait of Gibraltar is the unique and narrow connection between the Mediterranean basin and the open Atlantic Ocean. One of the main features of this place appears as the strong topographic constriction that happens both in the horizontal (minimum width of 14 km) and vertical (minimum depth of 250 meters) dimension in conjunction with the prese...
Article
Full-text available
In this paper, we analyze the pattern of distribution of three populations of picoplanktonic autotrophs measured using flow cytometry. Prochlorococcus sp., Synechococcus sp. and eukaryotic picoplankton were investigated at 58 stations to the south of the Iberian Peninsula including the northeastern Gulf of Cádiz, Strait of Gibraltar and northwester...
Article
Primary production was studied at nine sites distributed within the Strait of Gibraltar (Southern Spain) and NorthWestern (NW) Alboran Sea by analyzing photosynthesis-irradiance (P–I) relationships and integrated primary production rates in relation to the different types of Deep Chlorophyll Maxima (DCM) detected in the area. The characteristics of...
Article
Full-text available
Primary production was studied at nine sites distributed within the Strait of Gibraltar (Southern Spain) and North-Western (NW) Alboran Sea by analyzing photosynthesis-irradiance (P–I) relationships and integrated primary production rates in relation to the different types of Deep Chlorophyll Maxima (DCM) detected in the area. The characteristics o...
Article
Full-text available
The spatial distribution and size structure of microbial nanophytoplankton were analysed using flow cytometry and then related to water column structure and nutrient concentration in the Strait of Gibraltar. Microbial biomass increased as the Atlantic-Mediterranean interface (AMI) shoaled and mixing processes increased from SW to NE in the strait r...
Article
A conceptual model proposing the distribution and dynamics of water masses and chlorophyll maxima according to tidal cycle is presented for the Strait of Gibraltar. The proposal is based on the analysis of data registered in a section along the strait at different stages of the tidal cycle. Basic water characteristics were established from CTD cast...
Article
Hydrographic mesoscale structures in the North-western Alboran Sea show a high variability induced by a number of different factors. One of the most important is the differences in atmospheric pressure over the Mediterranean basin when compared to the Gulf of Cádiz. This difference modulates the zonal wind field in the Alboran Sea and the intensity...
Article
The selection and establishment of the structure (number and compartments, aggregation criteria, and trophic links) of the food webs is a critical task in trophic modelling. The present work proposes a systematic method to structure trophic networks in pelagic food webs. The biomass-size spectrum (BSS) is a well-established approach to analyze the...
Article
Full-text available
The output of a two-layer hydrodynamic model along a west–east section of the Gibraltar Strait is used to estimate tidal induced mixing between the Mediterranean and Atlantic water layers and to simulate the effects of mixing processes on biogeochemical fluxes and the pelagic community of the area. The hydrodynamic model is used to estimate interfa...
Article
Full-text available
A set of weekly-composite SeaWiFS (Sea-viewing Wide Field of view Sensor) imagery (from 1998 to 2004) has been used to asses the temporal and spatial variability of the surface chlorophyll distribution in the Northwestern Alboran Sea. Empirical Orthogonal Function (EOF) analysis of the images series shows the existence of three different regions in...
Article
The output of a two-layer hydrodynamic model along a west–east section of the Gibraltar Strait is used to estimate tidal induced mixing between the Mediterranean and Atlantic water layers and to simulate the effects of mixing processes on biogeochemical fluxes and the pelagic community of the area. The hydrodynamic model is used to estimate interfa...
Article
The spatial and temporal distributions of transparent exopolymer particles (TEP) were studied for the Gulf of Caiz, by analyzing its abundance in the euphotic and upper mesopelagic zones. Both layers of the water column should reflect a distinct pattern in TEP distribution, as production of TEP is mainly linked to phytoplankton activity, which is s...
Article
The tidal cycle and its amplitude appear as an a priori forcing factor causing periodic mixing events on the Gibraltar Strait sill. These mixing events can supply nutrient-enriched deep waters to the surface atlantic layer flowing to the Mediterranean. Therefore these mixing phenomena have both important biological and biogeochemical implications a...
Article
Full-text available
Physical and biological properties of the water column in the Gulf of Cádiz area were examined during a survey in May 2001. The sampling region was dominated by the presence of a central warm core and anticyclonic circulation in the open ocean, upwelling processes nearby both Cape Santa María and Cape San Vicente, and a coastal counter current alon...
Article
Full-text available
The evolution of a natural plankton community in two microcosms with well-differentiated turbulence levels (10-3 W m-3 and 10-1 W m-3) was compared during artificially-generated blooms. Biomass-size spectra were used to assess the effects of the turbulent kinetic energy (TKE) on the plankton community. Picoplankton was the size range least affected...
Article
Full-text available
The evolution of a natural plankton community in two microcosms with well-differentiated turbulence levels (10-3 W m-3 and 10-1 W m-3) was compared during artificially-generated blooms. Biomass-size spectra were used to assess the effects of the turbulent kinetic energy (TKE) on the plankton community. Picoplankton was the size range least affected...
Article
Full-text available
A detailed description of high-amplitude steady topographic internal waves recorded at Camarinal Sill during a survey on the R.V. “Investigador” is presented. These internal waves are generated during the maximum outflow (westward) stage of the tidal current and remain over the sill for more than 4 h until the outflow slackens, then being released...
Article
This study presents a joint analysis of the distributions of some biogeochemical variables and their relation to the hydrodynamics of Gibraltar Strait. It is a synthesis paper that brings together many results obtained during CANIGO project. We show the role of hydrodynamics as a forcing agent for the plankton community structure in the Strait, wit...
Article
In order to estimate plankton biomass transport through the Gibraltar Strait, plankton biomass and velocity profiles were measured at three stations located in the eastern side of the Strait as a part of the CANIGO project. Abundance and biomass measurements were carried out for autotrophic (Prochlorococcus, Synechococcus and eukaryotic pico-nano-a...
Article
Diatoms and the large, fast-sinking aggregates they form during blooms play an important role in downward flux of particles in the ocean. To study how the aggregation process operates on particle dynamics, diatom blooms were generated and followed under controlled conditions in nutrient-enriched laboratory mesocosm where a homogeneous mixed surface...
Article
Full-text available
During a summer cruise in the Gulf of Cádiz area (Southern Iberian Peninsula), an upwelling episode off the eastern coast of Cape Santa María was noted. The observed temperature field data suggested an anticyclonic circulation from NW to SE and a velocity of the associated surfacecurrents ranging between 10 and 15 cm s−1 was estimated. Research was...
Article
Diatom aggregates are a significant component of the downward particle flux recorded by sediment traps during phytoplankton blooms. However, although these large parti- cles are an important vector for the transfer of carbon to the deep ocean, there is a lack of empirical approaches to formulate their generation at the ocean surface. There is also...
Article
The Gulf of Cádiz is an area of transition for Atlantic waters inflowing the Mediter- ranean and Mediterranean waters inflowing the Atlantic. Despite the potentials that this exchange dynamics can encapsulate, little is known on the biological response to the physical forcing in surface waters of the area. In this presentation we show a set of prel...
Article
Full-text available
Phytoplankton size structure is acknowledged as a fundamental property determining energy flow through 'microbial' or 'herbivore' pathways. The balance between these two pathways determines the ability of the ecosystem to recycle carbon within the upper layer or to export it to the ocean interior. Small cells are usually characteristic of oligotrop...
Article
Full-text available
The surface distribution of light attenuation due to particles (c) as well as chlorophyll-a and gelbstoff fluorescence (Fch and Fcd, respectively) were recorded during an OMEGA (EU funded, MAST III project) cruise in the northwestern Alborán Sea through a high spatial (zonally separated by 10 km and virtually meridionally continuous) and temporal (...
Article
Full-text available
This study presents the distribution and fluxes of dissolved nutrients in the Strait of Gibraltar, as well as their relationship to the microphytoplankton biomass distribution in the zone. In June and September 1997, the upper Atlantic inflowing waters west of the sill showed low nutrient concentrations. A significant increase was observed at the e...
Article
Full-text available
In this paper we present microplankton distribution patterns in the Strait of Gibraltar obtained during a cruise carried out in September 1997. Chlorophyll, microplankton abundance and biovolume increase from southwest to northeast, a tendency that coincides with a gradual elevation of the interface depth in the same direction. The vertical distrib...
Article
Full-text available
The results obtained from 59 stations sampled in the Gulf of Cadiz, Straits of Gibraltar and Alborán Sea (northwest sector) during July 1995 are analysed in this paper. The main hydrological characteristics recorded during the survey and their possible relationship with planktonic distribution and composition are presented. The eggs and larvae of a...