Eneko Bachiller

Eneko Bachiller
AZTI · Sustainable Fisheries Management - ICES

PhD

About

36
Publications
11,151
Reads
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366
Citations
Introduction
Scientific research: small scale fisheries, recreational fisheries, marine trophic ecology and species interactions, zooplankton. Laboratory work: Trophic ecology & trophodynamics of small pelagic fish (diet characterization). Other expertise: Scientific observer on surveys, fish sampling on local harbours, fish and zooplankton taxonomy. Main area of study: Bay of Biscay, Northeast Atlantic, Norwegian Sea, Mediterranean Sea.
Additional affiliations
July 2019 - April 2020
AZTI
Position
  • Fish sampler
March 2019 - June 2019
AZTI
Position
  • Scientific observer (tuna fishing)
Description
  • On board Playa de Noja (PEVASA)
September 2018 - March 2019
Institut de Ciències del Mar
Position
  • Research Associate
Description
  • Scientific stay in AZTI - Pasaia (Gipuzkoa)
Education
October 2007 - February 2013
AZTI
Field of study
  • Trophic ecology of small pelagic fish in the Bay of Biscay: ecological effects of trophic interactions
September 2006 - September 2007
National Oceanography Centre, Southampton
Field of study
  • Marine Environment and Resources - MSc project (AZTI-Tecnalia): "Feeding behaviour and diet of anchovy juveniles (Engraulis encrasicolus L.) in the Bay of Biscay"
September 1999 - September 2004

Publications

Publications (36)
Article
Full-text available
Small pelagic fish are the link between planktonic production and higher trophic levels. Competition for resources may play a role in the population dynamics of species, some of them probably standing out from the others due to greater feeding success. It is therefore important to understand the trophic niche of species overlapping both spatially a...
Article
Full-text available
The Norwegian spring-spawning (NSS) herring (Clupea harengus), blue whiting (Micromesistius poutassou) and Northeast Atlantic (NEA) mackerel (Scomber scombrus) are extremely abundant pelagic planktivores that feed in the Norwegian Sea (NS) during spring and summer. This study investigated the feeding ecology and diet composition of these commercial...
Article
Full-text available
This work combines state-of-the-art methods (DNA metabarcoding) with classic approaches (visual stomach content characterization and stable isotope analyses of nitrogen (δ15N) and carbon (δ13C)) to investigate the trophic ecology of anchovy (Engraulis encrasicolus) and sardine (Sardina pilchardus) at high taxonomic and spatial resolution in the Wes...
Article
Full-text available
The northward expansion of round sardinella (Sardinella aurita) in the Mediterranean Sea, together with declines and fluctuations in biomass and landings of European sardine (Sardina pilchardus) and anchovy (Engraulis encrasicolus) observed in recent decades, may suggest potential inter-specific competition in the pelagic domain. The coexistence of...
Article
Full-text available
The present study uses bioenergetics modeling to estimate the annual consumption of the main zooplankton groups by some of the most commercially important planktivorous fish stocks in the Northeast Atlantic, namely Norwegian spring-spawning (NSS) herring (Clupea harengus), blue whiting (Micromesistius poutassou) and NEA mackerel (Scomber scombrus)....
Article
We quantified the incidence of microplastics in the gut contents of the European sardine (Sardina pilchardus) and anchovy (Engraulis encrasicolus) in the Northwestern Mediterranean Sea and tested which variables influence this abundance, including the prevalence of parasites (i.e., trematoda larvae and nematodes). We detected a 58% occurrence of mi...
Article
Recruitment of sardine (Sardina pilchardus Walbaum, 1792) and anchovy (Engraulis encrasicolus Linnaeus, 1758) is thought to be regulated by predation of their eggs and larvae. Predators of sardine and anchovy can be identified by visual taxonomic identification of stomach contents, but this method is time consuming, tedious and may underestimate pr...
Presentation
Full-text available
Intraguild predation between small pelagic fish as regulation mechanism of early life stage survival may have a significant effect on inter-annual variations in fish abundance and recruitment variability. For instance, although traditionally linked to physical (e.g. transport, retention) processes, survival of anchovy early life stages in the main...
Article
Full-text available
Semi-automated classification of zooplankton allows increasing the number of processed samples cost-effectively, albeit with a relatively limited taxonomic accuracy, partly because cost-efficiency trade-off but also due to technological limitations that might be overcome in the future. The present study tests the suitability of using a cost-efficie...
Presentation
Intraguild predation between small pelagic fish as regulation mechanism of early life stage survival (e.g. top-down control) may have a significant effect on inter-annual variations in fish abundance and recruitment variability. For instance, although traditionally linked to physical (e.g. transport, retention) processes, survival of anchovy early...
Presentation
Intraguild predation between small pelagic fish as regulation mechanism of early life stage survival (e.g. top-down control) may have a significant effect on inter-annual variations in fish abundance and recruitment variability. For instance, although traditionally linked to physical (e.g. transport, retention) processes, survival of anchovy early...
Poster
Full-text available
Sardines (Sardina pilchardus) and anchovies (Engraulis encrasicolus) are small pelagic species inhabiting the Bay of Biscay. Due to their high commercial value, significant effort is devoted to understand the factors affecting the recruitment of these species, which is partly regulated by mortality of their eggs and larvae, predated by other organi...
Presentation
Full-text available
There are indications of top down control of zooplankton by pelagic planktivorous fish in the Norwegian Sea (NS). The present study uses bioenergetics modeling to estimate the annual consumption of the main zooplankton groups by the most abundant small pelagic fish feeding in the NS: the Norwegian spring-spawning (NSS) herring (Clupea harengus), bl...
Data
Average prey composition in percentages (mean mg fish-1 weighed with the total estimated abundance per station) for mackerel, herring and blue whiting in spring and summer and from 2005 to 2010, based on the highest taxonomic level categorization (i.e. 45 prey groups). Stations included in this analysis were those within the Atlantic water mass and...
Data
Zooplankton total biomass (dry weight, g m-2) distribution per year (2005–2010) in May and July. Dark grey lines indicate water mass boundaries for each year and season, and light grey lines represent the average boundaries during each season. (TIF)
Data
Estimated fish abundance distribution per year (2005–2010) in May and July for (A) mackerel (July), (B) herring and (C) blue whiting. Abundances per grid square (see section 2.3) are defined as thousands of tonnes for herring and blue whiting, and in CPUE for mackerel. Black symbols represent sampling stations. Dark grey lines indicate water-mass b...
Presentation
The Norwegian spring-spawning (NSS) herring (Clupea harengus), blue whiting (Micromesistius poutassou) and Northeast Atlantic (NEA) mackerel (Scomber scombrus) are extremely abundant pelagic planktivores that feed in the Norwegian Sea (NS) during spring and summer. This study investigated the feeding ecology and diet composition of these commercial...
Article
Full-text available
In the course of the pasttwodecades, Atlanticmackerel,Scomberscombrus, haveexpandedtheirsummerfeeding distributionin theNorwegian Sea substantially, and now potentially overlap with pelagic larvae of Norwegian spring-spawning herring, Clupea harengus, as these drift northwards. Mackerel are known to be opportunistic predators, and the aim of this s...
Article
Full-text available
Small pelagic fish can play an important role in various ecosystems linking lower and upper trophic levels. Among the factor behind the observed inter-annual variations in small pelagic fish abundance, intra- and interspecific trophic interactions could have a strong impact on the recruitment variability (e.g. anchovy). Egg cannibalism observed in...
Presentation
Full-text available
The Norwegian Sea (NS) is the feeding ground for three potentially vastly abundant pelagic populations: Norwegian spring-spawning (NSS) herring (Clupea harengus), blue whiting (Micromesistius poutassou) and Northeast Atlantic (NEA) mackerel (Scomber scombrus), the latter partly having their summer feeding in the NS. These planktivorous populations...
Presentation
Atlantic mackerel, Scomber scombrus, have in the past two decades expanded the summer feeding distribution in the Norwegian Sea substantially, and now potentially overlaps with pelagic larvae of Norwegian spring spawning (NSS) herring, Clupea harengus, drifting northwards. Mackerel is known as an opportunistic predator, and therefore can feed on NS...
Article
Full-text available
PhD-based Divulgative Science Articles - CAF-Elhuyar 1st Award (2014)
Article
Full-text available
Bachiller, E. and Irigoien, X. 2013. Allometric relations and consequences for feeding in small pelagic fish in the Bay of Biscay. – ICES Journal of Marine Science, 70:232–243. The body size of fish is an important factor in determining their biology and ecology, as predators eat prey smaller than themselves. Predator mouth size restricts the avail...
Article
Full-text available
Bachiller, E., Cotano, U., Boyra, G., and Irigoien, X. 2013. Spatial distribution of the stomach weights of juvenile anchovy (Engraulis encrasicolus L.) in the Bay of Biscay. – ICES Journal of Marine Science, 70: 362–378. Previous studies have shown that the survival of larval and juvenile anchovy off the continental shelf in the Bay of Biscay is n...
Presentation
Anchovy and sardine have a central place in upwelling ecosystems where they constitute an important part of commercially exploited species, and play a role as forage fish for numerous predators. Different hypotheses have been suggested to explain interannual and long term variations in fish abundance and the strong reduction in anchovy biomass duri...
Presentation
Most pelagic fish species, and in particular anchovy (Engraulis encrasicolus) and sardine (Sardina pilchardus) in upwelling systems, undergo large interannual and interdecadal fluctuations in abundance (Cury, 1988; Lluch-Belda et al., 1989; Baumgartner, 1992; Schwartzlose et al., 1999; Chavez et al., 2003). Anchovy and sardine have a central place...
Article
Full-text available
The rapid development of image-based methods for counting and classifying zooplankton has made it possible to analyze large numbers of samples in a semiautomated way. However, using semiautomated methods to deal with hundreds of samples increases the risk of propagating errors during the procedure. Furthermore, classification methods based on train...
Article
Full-text available
In trophic studies of small pelagic fish, comparisons between gut contents and the available food in field are commonly limited by the sampling procedure. In this sense, different sized zooplankton samples can differ depending on the mesh size of the sampling net. In the same way, the variability on the distribution of both predators and preys as a...
Thesis
Full-text available
Several studies have suggested that climate and oceanographic structure mediated changes in zooplankton abundance and composition might influence fish recruitment with consequences for fish populations and fish management. In this sense fisheries science now recognizes the influence of environment and an ecosystem approach to management is being pr...
Article
Full-text available
Rapid development of semi-automated zooplankton counting and classification methods has carried out new chances when defining objectives for plankton distribution studies. Image analysis allows processing many more samples than under microscope classification with less effort and faster, but with lower taxonomical resolution. Although research in t...
Presentation
Full-text available
The rapid development of image-based methods for counting and classifying zooplankton has made it pos- sible to analyze large numbers of samples in a semiautomated way. However, using semiautomated methods to deal with hundreds of samples increases the risk of propagating errors during the procedure. Furthermore, clas- sification methods based on t...
Thesis
The diet of juvenile anchovies in the Bay of Biscay was investigated. We analysed the effect of being on and off the shelf, sampling hour and location according to main hydrographic features (i.e. Gironde Estuary and Arcachon Areas). Firstly zooplankton samples were analyzed with image analysis, trying different methods in order to obtain more accu...

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Projects

Project (1)
Project
The ecosystem in the Norwegian Sea has been under constant change during the last decades. Ecologically and commercially important pelagic fish stocks; Norwegian Spring Spawning herring, North East Atlantic mackerel, and blue whiting, have all had their turn in being the most abundant pelagic species, however, the exact nature of the interspecific interactions between these species is still poorly understood. In the last decade the summer feeding area of the NEA mackerel stock has been expanding drastically and in 2014 mackerel was observed all over the Nordic Seas. While mackerel stock is thriving, Norwegian spring spawning herring stock is currently at its lowest level in 20 years. Some hypothesize that the absence of strong year classes of Norwegian spring spawning herring is a direct result of expansion of mackerel as they prey upon herring larvae. In addition to the suggestion that mackerel is competing for food with herring, it has also been hypothesized that by eating herring larvae, the mackerel would worsen the already dire conditions of many sea bird populations along the Norwegian coast. In the spirit of ecosystem based fisheries management the supposedly detrimental effect of mackerel on other fish stocks and sea birds should be taken into account in the management of the Norwegian Sea Ecosystem. In this study we aim at improving our understanding about the species interactions and the dynamics of the Norwegian Sea ecosystem by developing and using modern methods for identifying and quantifying the diet of these ecologically and economically important pelagic fish populations. We will use modern statistical methods to scrutinize these data, and end-to-end ecosystem models to test the hypotheses regarding ecosystem dynamics from plankton, via fish, to sea birds under the current climate change. This project is an investment in understanding and long-term monitoring and management of the Norwegian Sea and other ecosystems.