Izaskun Zorita

AZTI · Marine Research Division

The accumulation of contaminants in aquatic organisms is of concern to human health due to the potential for exposure through the consumption of seafood. This dataset presents the levels of 17 polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), and 12 dioxin-like polychlorinated biphenyls (DL-PCBs) (PCB-81, PCB-77, PCB-126, PCB-169, PCB-...

Introduction Estuarine ecosystems are under high anthropogenic pressure and receive a wide Q7 variety of contaminants, including metals. They can remain trapped in estuarine sediments at high concentrations for long periods but eventually they can be released to the overlying water and become toxic for the resident benthic biota. As a consequence,...

The expansion of mussel aquaculture is limited by the availability of spat and production on land is dependent on costly cultures of microalgae as feed. Substitution of algae with microencapsulated feeds can reduce feed contaminations, ease the storage and extend the shelf life, ensuring stable production of consistent quality at sustainable costs....

Mussel farming is an emerging activity on the Basque coast. The experiences of mussel (Mytilus spp.) culture carried out in longlines in the coastal zone of Mendexa, between Ondarroa and Lekeitio (Southeastern Bay of Biscay), have been promising. However, some basic aspects of the biology of mussels cultured in offshore conditions are not yet well...

Since bivalves are filter-feeding organisms that can concentrate microorganisms and contaminants from the surrounding environment, there are strict sanitary requirements to ensure food safety. The legislation establishes a time limit of 2 months for shellfish relaying processes, but this study aims to determine whether the purification time can be...

In the present study the feasibility of black scallop Mimachlamys varia (Linnaeus, 1758) culture was evaluated using different growing systems under suspended conditions on the Basque coast (SE Bay of Biscay). Juveniles obtained from a hatchery, with a mean shell height of 23.6 ± 4.1 mm and a mean weight of 2.06 ± 1.09 g, were deployed in oyster ca...

Klima Aldaketa eta Itsasertzari buruzko Mugaz gaindiko V. Biltzarra. Laburpen zabalak V Congreso transfronterizo sobre Cambio Climático y Litoral. Abstracts extendidos V Congrès transfrontalier sur le Changement Climatique et Littoral. Abstract étendue V Cross border conference on climate and coastal change. Extended abstracts

This dataset presents the growth performance and survival of black scallops (Mimachlamys varia) reared under suspended conditions using different growing systems at two different sites of the Basque coast (SE Bay of Biscay). Monthly data on environmental variables (temperature, salinity, oxygen saturation and chlorophyll “a” concentration) in the w...

The 18th of January 2022 high concentrations of“paralytic shellfish poisoning” toxin were detected.in mussels Although these events are scarce, they entail serious health risks. Previous events of this toxin were registered in December 2018, and October 2018. To track the posible origins of the phytoplancton producing this toxin, we analysed the e...

Global expansion of bivalve aquaculture can drive sustainable protein production. Inland culture of mussel spat can play an important role in supporting extensive mussel farming. Nursery culture of bivalves is, however, dependent on nutritious, cost‐efficient, and more reliable diets for spat. The aim of this study was to assess the impact of dieta...

BIOGEARS addresses the challenge of minimizing the use of plastics in the sea by developing prototypes of biobased and compostable ropes, biogears, and examines their use in culture of mussels and seaweed Integrated Multi-Trophic Aquaculture (IMTA) systems. The goal of the biopolymers used in the development of the biogears is to achieve competitiv...

The effect of stocking density on the growth and mortality of the European flat oyster (Ostrea edulis Linnaeus, 1758) reared in lantern nets was evaluated, starting from spat up to the end of juvenile phase. Oysters were deployed in a raft on the Basque coast (SE Bay of Biscay) for 18 months. Oysters were divided into four densities ranging from 25...

Polycyclic aromatic hydrocarbons (PAHs) are priority contaminants in coastal and estuarine ecosystems under anthropogenic pressure. Although PAHs tend to accumulate in the sediment, toxicity for benthic flat fish such as soles may be caused by PAHs released from the sediment to the water column. Within this context, the present investigation aims a...

BIOGEARS contribuye a la generación de economía circular y apoya las estrategias de economía circular de plásticos desde un Blue Lab, que es un laboratorio de innovación para la generación de soluciones económicamente viables para afrontar el reto de la reducción del uso de plásticos en el ambiente marino y de su acumulación en forma de basura. Aun...

Whole-sediment toxicity assays contribute to elucidating the intricate association between the presence of contaminants in sediments and their toxicopathic effects in benthic fish. In the present study, Solea senegalensis juveniles were exposed under laboratory conditions to contaminated whole-sediments for 7 and 28 days. Sediments were obtained fr...

The extensive production of the Mediterranean mussel Mytilus galloprovincialis largely depends on environmental conditions for a stable production of spats, which are collected from the shore or rope collectors. Auxiliary inland hatchery and nursery facilities can support the production, by ensuring known quantity and quality of spats each year, re...

Aquaculture is an industry that creates economic value, employment, and economic support to rural and coastal areas and is called to address growing food demands, thus the European Union is keen on its large-scale expansion. Although offshore mussel aquaculture has been identified as a promising sector for aquaculture expansion, this sector makes u...

In the Basque Country (SE Bay of Biscay) the interest for offshore aquaculture has increased considerably during recent years. In 2012 AZTI set up an experimental facility at 2km off the coast of Mendexa (Biscay), to test the feasibility of culturing shellfish in open waters. This facility is installed at a deep of 45-50m and consists of longlines;...

The Bilbao estuary (SE Bay of Biscay) is a recovering ecosystem whose sediments are still contaminated. They represent a potential risk for the biota including benthic and demersal species living in direct contact with the sediment. In this context, the present study aims to survey trends of the health status of the Bilbao estuary based on sediment...

Seabirds have been widely used to monitor marine debris by the analysis of plastic ingestion. With the aim of obtaining the first data on ingestion of plastics by different seabird species in the Bay of Biscay and evaluating their suitability as biomonitors of plastic pollution in this area, a total of 159 seabirds of fifteen species were analyzed....

The supply of mussel seed is critical for the development of industrial mussel production. However, supplies of mussel seed from natural sources to the Mollusk Production Area (MPA), in the Southeastern Coast of the Bay of Biscay (Basque Country), have been scarcely studied. The aim of the present study is to evaluate the settlement and recruitment...

Efecto de la densidad en el crecimiento y mortalidad de la ostra japonesa Crassostrea gigas cultivada en aguas de la costa vasca (SE del Golfo de Bizkaia)

Mussel farming is an emerging activity in the Basque coast. The experiences of mussel (Mytilus spp.) culture carried out in long-lines in the coastal zone of Mendexa, between Ondarroa and Lekeitio (Southeastern Bay of Biscay), have been promising. However, some basic aspects of the biology of mussels cultured in offshore conditions are not yet well...

An important question in bivalve aquaculture is how many individuals of a certain species can be grown on a lease before growth is limited or before mortality becomes unacceptable. Thus, in the present study effects of stocking density on changes of total weight, length and survival were evaluated monthly along the production cycle of the Pacific o...

Efforts to develop offshore oyster and mussel aquaculture have been made in the Basque region since 2007. It is well known that differences in the temporal pattern of gonad condition is found in molluscs from different geographical origins. Thus, in new shellfish farming initiatives it is crucial to characterize the reproductive cycle to ascertain...

Micronuclei (MN) and nuclear buds (NB) frequency was assessed monthly over a one-year period in erythrocytes of common soles (Solea solea) from the Basque continental shelf, a minor disturbed area, in order to determine baseline levels and potential biotic and abiotic confounding factors within biomonitoring purposes. Both genotoxic parameters pres...

Plastic litter content in stomachs of seabirds, like the Northern Fulmar (Fulmarus glacialis), is being used as indicator of changes in levels of litter in environmental monitoring programs of the North Sea. Furthermore, one of the Ecological Quality Objectives for the North Sea (EcoQOs) adopted by the Oslo- Paris Convention (OSPAR) is based on the...

El País Vasco cuenta con un Plan Estratégico para el desarrollo de la acuicultura, incluido en el Plan Plurianual de la Acuicultura, que rota sobre 4 ejes principales (de la figura): simplificación administrativa, desarrollo ambiental sostenible, mercado e imagen y competitividad y desarrollo económico local. A su vez, el desarrollo de la acuicultu...

An important question in bivalve aquaculture is how many individuals of a certain species can be grown on a lease before growth is limited or before mortality becomes unacceptable. Regardless, the information about stocking density is scarce in the scientific literature and results are not always comparable. Thus, stocking density for oyster cultur...

Bivalve mollusc aquaculture has been considered as an economic diversification activity for fisheries in the strategic plans of the Basque Government. In the last years several initiatives of mollusc aquaculture have been set up in the Basque Coast. In the present study, results of the hydrodynamic and water quality characterization of the producti...

Using a long-term (1995–2014) monitoring network, from 51 sampling stations in estuaries and coasts of the Basque Country (Bay of Biscay), the objective of this investigation was to assess the responsiveness of 83 variables in water (18), sediments (27), biota (26), phytoplankton (2), macroinvertebrates (5) and fishes (5) to different human pressur...

Liver and gonad histopathology, biometric parameters and hepatic metal bioaccumulation were assessed monthly over a one-year period in common soles from the Basque continental shelf, in order to determine baseline levels and confounding factors within biomonitoring studies. Biometric parameters and hepatic metal bioaccumulation varied according to...

Bioaccumulation and biological effects of pollution were assessed in mussels (Mytilus galloprovincialis) caged for one month at three sites in the Oiartzun estuary (south-eastern Bay of Biscay, Spain) with the aim of evaluating their usefulness within the investigative monitoring defined in the European Union Water Framework Directive (WFD). The hi...

Bivalve histopathology has become an important tool in aquatic toxicology, having been implemented in many biomonitoring programmes worldwide. However, there are various gaps in the knowledge of many sentinel organisms and the interference of confounding factors. This work aimed (i) to develop a detailed semi-quantitative histopathological index of...

Sole and hake, together with sediments, were collected during two campaigns along the Basque continental shelf to study the utility of two existing histopathological indices for assessing the biological effects of contaminants to implement the European Marine Strategy Framework Directive. Hepatic and gonadal histopathology were measured, and metal...

Biofouling formation on submerged structures placed in the marine environment is a worldwide problem. Many of the treatments that are used to combat biofouling provoke adverse effects on marine organisms, and thus, their use is being restricted. In this context, the society is requesting the development of alternative effective and environmental fr...

Monitoring the quantification of fish diseases is a well established and widely used tool to assess pollution effects in marine environments. However, there is sparse published information on externally visible diseases and on liver histopathology of common sole (Solea solea), a promising sentinel species in south-western Europe. To address this i...

Imposex and butyltin body burden were assessed in 2011 along the Basque coast (northern Spain) in two gastropod species (Nassarius reticulatus and Nassarius nitidus) four years after an initial survey in 2007. The aim of this re-survey was to monitor the effectiveness of the European ban on the use of tributyltin (TBT) based antifouling paints on s...

The study aimed to assess and compare the digestive capacity in individuals of Senegalese sole (SSE) and common sole (SSO), captured in two different areas, one inner (INN) and one outer (OUT), along the Nervión estuary in the southeastern Bay of Biscay. The final objective of the work was to further use the results obtained in the understanding of...

The European Marine Strategy Framework Directive (Directive 2008/56/EC), establishes a framework and common objectives for the protection and conservation of the marine environment. This Directive requires the implementation of all measures necessary to achieve the Good Environmental Status by 2020, according to 11 qualitative descriptors: (1) bio...

As the introduction of alien species represents one of the most important causes of biodiversity loss, it is crucial to study the distribution of alien species in order to control or eradicate their introduction and spread. Thus, the present study aimed to analyse the spatial distribution and temporal trends of soft-bottom marine benthic alien spec...

Native and caged mussels were used in combination for the monitoring of pollution biological effects through an integrative biomarker approach. Mussels (Mytilus galloprovincialis) were deployed in cages in two well-known model localities with different pollution levels in the Basque coast. After 3 weeks caged and native mussels were collected from...

Ecological Impacts of Toxic Chemicals presents a comprehensive, yet readable account of the known disturbances caused by all kinds of toxic chemicals on both aquatic and terrestrial ecosystems. Topics cover the sources of toxicants, their fate and distribution through the planet, their impacts on specific ecosystems, and their remediation by natura...

There is a need for sensitive biological effect methods by which to detect impacts of chronic exposure to low concentrations of contaminants. Two methods shown to be potentially useful for monitoring purposes in fish include lysosomal membrane stability and peroxisome proliferation. These biological endpoints were assessed in Atlantic cod (Gadus mo...

The implementation of the Marine Strategy Framework Directive (MSFD) is directing European marine research towards the coordinated and integrated assessment of sea environmental status, following the ecosystem-based approach. The MSFD uses a set of 11 descriptors which, together, summarise the way in which the whole system functions. As such, the E...

Imposex assessment (imposition of male characters in female dioecious gastropods due to organotin compounds) in two gastropod species, Nassarius reticulatus and Nassarius nitidus, is detailed by a visual guideline. The information that appears in different sections is accompanied by photographs, diagrams and data summary reports with the aim of sol...

A biomonitoring program was carried out in spring and autumn in three pollution hot-spots and sensitive areas of the NW Mediterranean Sea using red mullets (Mullus barbatus) as sentinel organisms and a battery of biomarkers together with gonad histology. In fish from anthropogenic impacted areas (Fos-sur-mer, Cortiou, Arenzano, Delta of Ebro) lysos...

With the aim of assessing the biological effects of pollution along three gradients of pollution in the NW Mediterranean Sea, a biomonitoring survey was implemented using a battery of biomarkers (lysosomal membrane stability, lysosomal structural changes, metallothionein (MT) induction and peroxisome proliferation) in mussels over a period of two y...

Metallothioneins (MTs) are metal-inducible proteins that can be used as biomarkers of metal exposure. In mussels two families of MT isoforms (MT10 and MT20) have been characterized. In this study, mussels (Mytilus galloprovincialis) were exposed to 200 ppb Cd and 40 ppb Cu for 2 and 9 days to characterize the tissue and isoform specificity of metal...

In the present work, mussels (Mytilus edulis) were transplanted into a copper (Cu) gradient in Visnes (Norway) for a period of 3 weeks during November 2003. Sites 1 and 2 showed similar low levels of Cu, site 3 had intermediate Cu levels and site 4 was the most polluted with Cu as confirmed by AAS of digestive gland tissue. Values of lysosomal memb...

Metallothionein (MT) induction is widely used as a biomarker of exposure to metals in mussels. The aims of the present work were first to compare the suitability of spectrophotometry and differential pulse polarography (DPP) for MT detection in mussels exposed to 200 ppb cadmium for 9 days in a laboratory experiment and in mussels sampled in differ...