Xabier Irigoien

AZTI · Marine Research Division

The European Commission tendered the study “Marine Biodiversity Modelling” [RTD/2021/MV/10] to pursue the identification and characterization of a subset of candidate biodiversity models that could contribute to the implementation of the European Digital Twin of the Ocean (EU DTO). The EU DTO will be an operational infrastructure for digital ocean...

Automated positioning devices can generate large datasets with information on the movement of humans, animals and objects, revealing patterns of movement, hot spots and overlaps among others. This information is obtained after cleaning the data from errors of different natures. However, in the case of Automated Information Systems (AIS), attached t...

Dispersal and environmental gradients shape marine microbial communities, yet the relative importance of these factors across taxa with distinct sizes and dispersal capacity in different ocean layers is unknown. Here, we report a comparative analysis of surface and deep ocean microbial beta diversity and examine how these patterns are tied to ocean...

Increasing anthropogenic pressures on the coastal marine environments impact these ecosystems via a variety of mechanisms including nutrient loading, leading to eutrophication and increases in algal blooms. Here, we use a metagenomics approach to assess the taxonomic and functional changes of the microbial community throughout a nutrient enriched m...

A total of five mesozooplankton time series data sets were assembled to compare the seasonal and interannual patterns of abundance of calanoid copepods in the Western English Channel (Station L4), Celtic Sea, Bay of Biscay (Continuous Plankton Recorder), and the Cantabrian Sea (RADIALES time series, Santander, St-4 and St-6) from January 1992 to De...

We provide the raw acoustic data collected from the R/V Hesperides during the global Malaspina 2010 Spanish Circumnavigation Expedition (14th December 2010, Cádiz-14th July 2011, Cartagena) using a Simrad EK60 scientific echosounder operating at 38 and 120 kHz. The cruise was divided into seven legs: leg 1 (14th December 2010, Cádiz-13th January 20...

Contrary to epipelagic waters, where biogeochemical processes closely follow the light and dark periods, little is known about diel cycles in the ocean's mesopelagic realm. Here, we monitored the dynamics of dissolved organic matter (DOM) and planktonic heterotrophic prokaryotes every 2 h for one day at 0 and 550 m (a depth occupied by vertically m...

Establishing the foundations for a sustainable use of deep‐sea resources relies on increasing knowledge on this inaccessible ecosystem, which is challenging with traditional methods. The analysis of environmental DNA (eDNA) emerges as an alternative, but it has been scarcely applied to deep‐sea fish. Here, we have analyzed the fish eDNA contained i...

Hake, mackerel, horse mackerel, anchovy and sardine larvae were identified from samples of ichthyoplankton collected during eight surveys in the Bay of Biscay between 2000 and 2005. Comparative analyses were carried out to explore the early growth patterns of these species based on differences in body proportion and the interpretation of the otolit...

Global ocean warming, wave extreme events, and accelerating sea-level rise are challenges that coastal communities must address to anticipate damages in coming decades. The objective of this study is to undertake a time-series analysis of climate change (CC) indicators within the Bay of Biscay, including the Basque coast. We used an integrated and...

The deep-sea remains among the most unknown ecosystems on Earth despite its relevant role in carbon sequestration and increasing threat due to interest by fishing and mining industries. This, together with the recent discovery that the upper layer of this ecosystem (mesopelagic zone) harbors about 90% of the fish biomass on Earth, claims for a deep...

Fisheries in waters beyond national jurisdiction (“high seas”) are difficult to monitor and manage. Their regulation for sustainability requires critical information on how fishing effort is distributed across fishing and landing areas, including possible border effects at the exclusive economic zone (EEZ) limits. We infer the global network linkin...

The study of phenotypic variation patterns among populations is fundamental to elucidate the drivers of evolutionary processes. Empirical evidence that supports ongoing genetic divergence associated with phenotypic variation remains very limited for marine species where larval dispersal is a common homogenizing force. We present a genome‐wide scale...

The vertical distribution of subseafloor archaeal communities is thought to be primarily controlled by in situ conditions in sediments such as the availability of electron acceptors and donors, although sharp community shifts have also been observed at lithological boundaries suggesting that at least a subset of vertically stratified Archaea form a...

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...

Background Tropical habitats and their associated environmental characteristics play a critical role in shaping macroinvertebrate communities. Assessing patterns of diversity over space and time and investigating the factors that control and generate those patterns is critical for conservation efforts. However, these factors are still poorly unders...

Massive metagenomic sequencing combined with gene prediction methods were previously used to compile the gene catalogue of ocean and host‐associated microbes. Global expeditions conducted over the past 15 years have sampled to ocean to build a catalogue of genes from pelagic microbes. Here we undertook a large sequencing effort of a perturbed Red S...

Current methods for monitoring marine fish (including bony fishes and elasmobranchs) diversity mostly rely on trawling surveys, which are invasive, costly, and time‐consuming. Moreover, these methods are selective, targeting a subset of species at the time, and can be inaccessible to certain areas. Here, we used environmental DNA (eDNA), the DNA pr...

Prochlorococcus and Synechococcus are pico-sized cyanobacteria that play a fundamental role in oceanic primary production, being particularly important in warm, nutrient-poor waters. Their potential response to nutrient enrichment is expected to be contrasting and to differ from larger phytoplankton species. Here, we used a metagenomic approach to...

The Red Sea is characterized by higher temperatures and salinities than other olig-otrophic tropical regions. Here, we investigated the vertical and seasonal variations in the abundance and biomass of autotrophic and heterotrophic picoplankton. Using flow cytometry, we consistently observed five groups of autotrophs (Prochlorococcus, two population...

Global ocean expeditions have provided minimum estimates of ocean’s prokaryote diversity, supported by apparent asymptotes in the number of prokaryotes with sampling effort, of about 40,000 species, representing <1% of the species cataloged in the Earth Microbiome Project, despite being the largest habitat in the biosphere. Here we demonstrate that...

Current methods for monitoring marine fish diversity mostly rely on trawling surveys, which are invasive, costly and time-consuming. Moreover, these methods are selective, targeting a subset of species at the time, and can be inaccessible to certain areas. Here, we explore the potential of environmental DNA (eDNA), the DNA present in the water colu...

This comparison highlights that Automatic Identification System (AIS)-based methods to estimate fishing effort such as the Global Fishing Watch (GFW) methodology can provide the general pattern of relative distribution of fishing effort intensity. These results were obtained in an area where coverage is quite good in general and with good vessels r...

In the last few years, there has been increasing interest in the commercial exploitation of mesopelagic fish and a trawl-acoustic methodology has been recommended to make estimates of abundance of these resources. This study provides relevant information on the scattering properties of a key mesopelagic fish species in the Bay of Biscay, Mueller’s...

Identifying the role that environmental factors and biotic interactions play in species distribution can be essential to better understand and predict how ecosystems will respond to changing environmental conditions. This study aimed at disentangling the assemblage of the pelagic predator-prey community by identifying interspecific associations and...

Contrary to epipelagic waters, where biogeochemical processes closely follow the light and dark periods, little is known about diel cycles in the mesopelagic realm. Here, we monitored the dynamics of dissolved organic matter (DOM) and planktonic heterotrophic prokaryotes every 2 h for one day at the surface and 550 m (a depth occupied by mesopelagi...

This presentation summarizes the acoustic-based studies on mesopelagic species conducted by AZTI in the last years

By 2050 it is expected that food, clean drinking water and sustainable energy has to be produced for world population of closeto10 billion people. Ourseasandoceansrepresent71%ofearth'ssurface,yetitsspaceandresources today are not sustainably utilised to their full extent. The importance of the use of the marine environment is within the EU widely a...

This study investigates the impact of extreme heat wave events on long‐lived massive corals (Porites spp.) from the central Saudi Arabian Red Sea using trace element (Sr/Ca, Li/Mg, Mg/Ca, U/Ca, B/Ca and Li/Ca) records preserved in the coral skeleton for the period between 1992 and 2012. Prior to 1998, the trace element records show strong correlati...

This chapter introduces the environmental gradients that characterize the broader Red Sea habitat. The Red Sea is formed by an actively spreading rift and notably has only one natural connection to the Indian Ocean – a narrow, shallow opening known as the Strait of Bab al Mandab. The resultant isolation undoubtedly plays a key role in shaping the e...

Marine species have exhibited trends in their geographic distribution and phenology in recent decades, and these changes are triggered by climate variability or anthropogenic pressures. Northeast Atlantic albacore has recently been identified to show changes of this nature, although the underlying causes are still uncertain. The aim of this work wa...

Hydrographic and atmospheric forcing set fundamental constraints on the biogeochemistry of aquatic ecosystems and manifest in patterns of resource (nutrient) availability and recycling, species composition of communities, trophic dynamics, and ecosystem metabolism. In the Red Sea, gradients in environmental conditions and primary production have be...

Trophic cascades and amplification throughout bottom-up processes make marine prey-predators particularly vulnerable to synergistic effects of exploitation and climate change. Understanding the species interactions in marine ecological networks is hence key for biodiversity conservation and sustainable management of exploited species. The present s...

Several studies have been carried out on heavy metal pollution in mangrove ecosystems. However, the role of mangroves in heavy metal remobilization is still relatively unknown. On one side, mangrove woody organs and soils sequester heavy metals for long time periods, but on the other hand, senescence of mangrove leaves may return these metals colle...

Estudios recientes sugieren que los depredadores marinos, y en especial las aves marinas, dependen sustancialmente de la presencia de otros depredadores para localizar el alimento. Este tipo de asociaciones interespecíficas también han sido ampliamente descritas entre los cetáceos, donde grupos mixtos de delfínidos han sido frecuentemente observado...

Abstract Seagrasses play an important role in climate change mitigation and adaptation, acting as natural CO2 sinks and buffering the impacts of rising sea level. However, global estimates of organic carbon (Corg) stocks, accumulation rates and seafloor elevation rates in seagrasses are limited to a few regions, thus potentially biasing global esti...

Future scenarios of fish stocks and the impacts of climate variability and change on fisheries are critical to anticipate and minimize potential economic losses in this sector. In this study, we assessed the impact of recent sea warming and future climate change on anchovy in the Bay of Biscay, where sea surface temperature has increased in the las...

The vast majority of marine dissolved organic carbon (DOC), the largest reservoir of reduced carbon on Earth, is believed to accumulate in the abyssal layers of the ocean over timescales of decades to millennia. However, evidence is growing that small animals that migrate vertically every day from the surface to mesopelagic layers are significantly...

Red Sea mangroves occur in an oligotrophic sea without permanent freshwater inputs. Understanding the mechanisms to cope with nutrient limitation is, therefore, important to understand their distribution and nutrient dynamics in coastal ecosystems. We measured total number of meristems to estimate their leaves production and nutrients (N, P, and Fe...

Clownfishes are an excellent model system for investigating the genetic mechanism governing hermaphroditism and socially-controlled sex change in their natural environment because they are broadly distributed and strongly site-attached. Genomic tools, such as genetic linkage maps, allow fine-mapping of loci involved in molecular pathways underlying...

In the version of this Article originally published, the potential carbon loss from soils as a result of mangrove deforestation was incorrectly given as ‘2.0–75 Tg C yr–1’; this should have read ‘2–8 Tg C yr–1’. The corresponding emissions were incorrectly given as ‘~7.3–275 Tg of CO2e’; this should have read ‘~7–29 Tg of CO2e’. The corresponding p...

Global patterns of planktonic diversity are mainly determined by the dispersal of propagules with ocean currents. However, the role that abundance and body size play in determining spatial patterns of diversity remains unclear. Here we analyse spatial community structure - β-diversity - for several planktonic and nektonic organisms from prokaryotes...

Mangroves forests of Avicennia marina occupy about 135 km² in the Red Sea and represent one of the most important vegetated communities in this otherwise arid and oligotrophic region. We assessed the soil organic carbon (Corg) stocks, soil accretion rates (SAR; mm y⁻¹) and soil Corg sequestration rates (g Corg m⁻² yr⁻¹) in 10 mangrove sites within...

Most vertebrates have a duplex retina comprising two photoreceptor types, rods for dim-light (scotopic) vision and cones for bright-light (photopic) and color vision. However, deep-sea fishes are only active in dim-light conditions; hence, most species have lost their cones in favor of a simplex retina composed exclusively of rods. Although the pea...

Mesopelagic fish are largely abundant poorly studied fish that are still intact, but which, due to their potentially great added value, will be imminently exploited by humans. Therefore, studies that provide information to anticipate the anthropogenic impact on this important resource are urgently needed. In particular, knowledge about their connec...

Patterns of variability in diversity (alpha and beta), abundance, and community structure of soft-bottom macrobenthic assemblages were investigated across an inshore/offshore environmental gradient in the central Red Sea. A total of three distinct soft-substrate biotopes were identified through multivariate techniques: seagrass meadows, nearshore a...

Patterns of variability in diversity (alpha and beta), abundance, and community structure of soft-bottom macrobenthic assemblages were investigated across an inshore/offshore environmental gradient in the central Red Sea. A total of three distinct soft-substrate biotopes were identified through multivariate techniques: seagrass meadows, nearshore a...

An important aspect of population dynamics for coral reef fishes is the input of new individuals from the pelagic larval pool. However, the high biodiversity and the difficulty of identifying larvae of closely related species represent obstacles to more fully understanding these populations. In this study, we combined morphology and genetic barcodi...

Abundance of gobiid species in the samples. (PDF)

Primers used for the DNA barcoding. (PDF)

List of non-gobiid taxa identified in the samples. (PDF)

Assignment at the sub-family level by combined DNA barcoding and morphology. (PDF)

Abundance of apogonid species in the samples. (PDF)

Abundance of labrid, pomacentrid and scarid species in the samples. (PDF)

Dates of ichthyoplankton sampling. (PDF)

List of gobiid taxa identified in the samples. (PDF)

Abundance of encountered families in the samples. (PDF)