Jose L. Rueda

• PhD
• Senior Researcher at Instituto Español de Oceanografia

Seafloor elevations (e.g., seamounts, banks, mounds) are essential underwater features for supporting and maintaining global marine biodiversity. Such geomorphological features might be of particular relevance to preserve biodiversity in the Mediterranean Sea, where a high number of anthropogenic impacts threaten deep-sea ecosystems. Using imagery...

The composition and structure of circalittoral and bathyal soft bottom echinoderm assemblages along the northern Alboran Sea, including the Alboran Ridge, have been studied in relation to sediment and near-bottom water masses characteristics. Samples were taken using a beam-trawl (50 sampling stations from 40 to 774 m depth) during 2014, 2015 and 2...

The Alboran Sea is the westernmost sub-basin of the Mediterranean Sea, and it is connected to the Atlantic Ocean through the Strait of Gibraltar. The Alboran Ridge is located in the middle of the Alboran Sea and represents a hotspot of biodiversity in the Mediterranean Sea. Besides their critical importance, there are few studies on the communities...

The arrival of a new invasive alga, Rugulopteryx okamurae, in the Strait of Gibraltar (SoG) in 2015 marked an unprecedented milestone in the North African and, later, in the European marine ecosystems. Nowadays, it is colonising vast infralittoral areas and significantly modifying some habitats and associated communities of the southern Iberian Pen...

Since Tagoro volcano erupted in 2011, several impacts have been associated to the volcano formation process, some of which are still present to date. This chapter is a review of the marine environmental perturbations caused by Tagoro volcano as a new geological structure, but thoroughly onto the partly annihilated benthic and demersal pre-existing...

The shallow Tagoro submarine volcano monitoring represents a unique opportunity not only for improving our sparse understanding of submarine volcanic processes in specific scientific fields as physical and chemical oceanography or marine geology but also its interactions over the marine biology in one of the richest marine ecosystems in Europe. Thi...

Molluscs of Chella Bank and its surroundings were studied from 21 samples collected with a van Veen grab in the depth range 95-729 m. A total of 299 taxa were identified (77 live-taken), thus increasing by more than 95% the species of molluscs reported in the recently declared site of community importance “Sur de Almería–Seco de los Olivos”. Two of...

The invasive seaweed Rugulopteryx okamurae has recently arrived in Europe from the western Pacific. Its explosive spread on coastal areas of the Gulf of Cádiz (GoC), Strait of Gibraltar and Alboran Sea is spoiling native coastal ecosystems and inflicting heavy losses on ecosystem services. We discovered for the first time large amounts (up to 17 g...

Introduction and methods Marine litter density, distribution and potential sources, and the impact on canyon seafloor habitats were investigated in the Motril, Carchuna and Calahonda canyons, located along the northern margin of the Alboran Sea. During the ALSSOMAR-S2S oceanographic survey carried out in 2019, canyon floor imagery was collected by...

Meadows of the seagrass Posidonia oceanica inhabit most infralittoral bottoms of the Mediterranean Sea and are considered one of the main climax stages of the infralittoral environment. This seagrass has its western distributional limit along the coast of the Alboran Sea. Taking into account the decline of P. oceanica meadows and the global scenari...

Multi-species bottom trawl fisheries are one of the human activities with a great impact on the benthic habitats and their associated biota. This study provides estimates of the bottom trawling activity (effort), catches and landings of the main commercial species as well as an estimation of the total revenue (TR) generated inside a mud volcano fie...

This study analyses the samples collected annually (2012 to 2018) on circalittoral and bathyal soft bottoms (30 to 800 m) by the MEDITS surveys in the northern Alboran Sea (including Alboran Island) and the Gulf of Vera to determine the composition, structure and distribution of decapod crustacean assemblages. A total of 94 decapod crustacean speci...

The presence of different water masses in depth may influence the species distribution and community structure in deep-sea benthic ecosystems. In the North Atlantic, the Mediterranean Outflow Water (MOW) represents an important forcing water mass, whose influence on the distribution of cold-water corals in the northern European margins has been par...

Carbonate mounds clustering in three fields were characterized on the upper continental slope of the northern Alboran Sea by means of a detailed analysis of the morphosedimentary and structural features using high-resolution bathymetry and parametric profiles. The contemporary and past benthic and demersal species were studied using ROV underwater...

A new species of gastropod, Episcomitra angelesae (Neogastropoda: Mitridae), is described from specimens collected in the upper bathyal level of the Alboran Sea (Seco de los Olivos and Alboran Ridge). The new species is compared with other similar species known from the Atlanto-Mediterranean area, including Episcomitra zonata (Marryat, 1819) and Is...

Extensive beds of the deep-sea mussel Bathymodiolus mauritanicus (currently also known as Gigantidas mauritanicus ) linked to active cold seeps related to fissure-like activity on Al Gacel mud volcano, Gulf of Cádiz, were filmed and sampled for the first time during the oceanographic expedition SUBVENT-2 aboard R/V Sarmiento de Gamboa. Al Gacel mud...

This study focused on the assessment and quantification of discards generated by clam fisheries along the northern Alboran Sea (western Mediterranean). Discard samples (n = 278) were collected throughout one year on board nine commercial vessels. A total of 129 species were identified, mostly represented by molluscs (72 spp.), arthropods (20 spp.)...

may be also exacerbated by other anthropogenic activities such as fishing. Submarine canyons represent the most significant seafloor litter sinks. In this work, the distribution and density of anthropogenic activity indicators in three submarine canyons (Motril, Carchuna and Calahonda) of the northern margin of the Alboran Sea are characterized, fo...

Tres de las cuatro nuevas especies de briozoos se han descrito con material procedente del golfo de Cádiz, mientras que la cuarta fue localizada en el mar de Alborán. A ellas se suman varias citas nuevas tanto para el Atlántico como para el Mediterráneo andaluz. - Publicación en revista de divulgación Quercus

Implementing European marine policies in the deep waters of the North Atlantic

Towards the assessment of North Atlantic deep sea ecosystems’ status: opportunities and challenges unraveled by the ATLAS project.

In this work, we characterize the morphology and recent sedimentary processes of two shelf-indenting submarine canyons (Motril and Carchuna) on the northern margin of the Alboran Sea. To achieve this aim, we used multibeam bathymetric data, seafloor imagery and short sediment cores (up to 50 cm). The Carchuna Canyon is deeply incised in the shelf,...

Submarine canyons are major morphological features incising continental margins and constitute the main pathways for shelf-to-basin sediment transfer and flux of contaminants and waste. The effectiveness of present-day canyon sediment transport depends largely on the proximity to a major sediment source from the continent, such as riverine or litto...

Litter enters the seas mostly from coastal and marine anthropogenic activities and travel long distances before being stranded at the seafloor, where is influenced by the seafloor geomorphology as well as oceanographic and sedimentary processes. Submarine canyons constitute the main pathways for the sediment transfer, flux of contaminants and waste...

The goal of the Project LIFE IP INTEMARES "Integrated, innovative and par- ticipatory management of the Natura 2000 network areas in the Spanish marine environment" is to achieve a consolidated network of marine spaces of the Natura 2000 Network, managed efficiently, with the active participation of the sectors involved and with research as basic t...

Benthic habitats, as well as their associated biota, have been studied in the Alboran Sea since the nineteenth century, with a very significant increase of knowledge in the last five decades. The geographical location of the Alboran Sea between three different biogeographical regions, the complex oceanography and the heterogeneous seafloor promote...

Marine Protected Areas (MPAs) and Key Biodiversity Areas (KBAs) are important tools for preserving species, habitats and ecological-geological-oceanographical processes. Nowadays, more than 10% of the Alboran Sea is under some protected figure or is on its way to be protected. This chapter presents the current state of the MPAs and KBAs of the Albo...

In this work, we integrate five case studies harboring vulnerable deep-sea benthic habitats in different geological settings from mid latitude NE Atlantic Ocean (24–42° N). Data and images of specific deep-sea habitats were acquired with Remoted Operated Vehicle (ROV) sensors (temperature, salinity, potential density, O2, CO2, and CH4). Besides doc...

This article offers an overview of the main sedimentary systems defining the geomorphology of deep sea environments from low to high latitudes. Mass-transport deposits, turbidite systems, contourites, volcaniclastic aprons, glacial trough mouth systems, carbonate mounds and other bathyal systems, such as pelagites, hemipelagites, mid-ocean channels...

Highlights Gazul MV presents a high geomorphological variability and diversity of bottom types. Six main epibenthic assemblages have been identified conforming habitats. Hard bottoms of the MV edifice contain the most biodiverse assemblages. Cold-water coral communities are dominated by Madrepora oculata. Gazul MV harbors different vulnerable...

Divulgative paper published in Journal Eco Magazine, Deep Sea Issue

Chella Bank (also known as Seco de los Olivos seamount) is a volcanic submarine elevation (76-700 m deep) located ca. 16 km off the southern coast of Spain, within the Alboran Sea, in the Atlantic-Mediterranean transition zone. It represents a biodiversity hotspot for Europe, with more than 600 species listed to date, and contains several habitats...

The deep sea is the largest biome on Earth but the least explored. Our knowledge of it comes from scattered sources spanning different spatial and temporal scales. Implementation of marine policies like the European Union's Marine Strategy Framework Directive (MSFD) and support for Blue Growth in the deep sea are therefore hindered by lack of data....

Digitaria digitaria, a small astartid usually less than 10 mm in length, has a non-brooding behaviour in spite of its limited space for gonad development. This species lives in highly unstable environments with strong currents, which represent a challenge for fertilization and larval settlement. The studied population of D. digitaria from the Strai...

Molluscs from the Gazul mud volcano and its adjacent areas in the northern Gulf of Cádiz were studied using differ­ent sampling methods. This mud volcano has vulnerable deep-sea habitats and a potential high biodiversity. A total of 232 species were identified from the taxocoenosis and thanatocoenosis, of which 86 are new records for the Spanish ma...

The Mediterranean is a semi-enclosed sea, with a narrow natural connection —the Strait of Gibraltar— through its western basin to the North Atlantic. Many studies have investigated how the inflow of North Atlantic Surface water into the Mediterranean shapes the faunal composition and abundance of the shallow-water benthic communities of the Western...

This study examines material collected in the northern part of the Gulf of Cádiz, in the Northeastern Atlantic Ocean, between the Iberian Peninsula and northern Africa, at 300–1200 m depth, within the Site of Community Importance “Volcanes de fango del Golfo de Cádiz” (Mud volcanoes of the Gulf of Cádiz, ESZZ-12002). Several previous studies were c...

The Iberian margin in the Gulf of Cádiz hosts a fluid venting area embedded into a contourite depositional drift and is a natural laboratory to study how multiple interacting processes shape the seafloor. A high-resolution morpho-sedimentary analysis, based on geophysical data, sediment samples and submarine imagery, has been carried out; the onset...

Circulation patterns in the North Atlantic Ocean have changed and re-organized multiple times over millions of years, influencing the biodiversity, distribution, and connectivity patterns of deep-sea species and ecosystems. In this study, we review the effects of the water mass properties (temperature, salinity, food supply, carbonate chemistry, an...

The Gulf of Cádiz represents an area of extensive seepage of the south-western Iberian Peninsula that is located between two continents and basins, where a high geomorphologic, sedimentary and environmental complexity occurs. In the present study, epibenthic communities were investigated in a mud volcano field containing four mud volcanoes (Gazul,...

The deep sea plays a critical role in global climate regulation through uptake and storage of heat and carbon dioxide. However, this regulating service causes warming, acidification and deoxygenation of deep waters, leading to decreased food availability at the seafloor. These changes and their projections are likely to affect productivity, biodive...

The Canary Islands are a volcanic alignment of seven islands that conforms an archipelago located in the northwestern part of the still active Nubian (African) tectonic plate. The archipelago showed its latest volcanic activity south off El Hierro Island in 2011, resulting in the formation of the newest underwater volcano, known as Tagoro, for the...

Bottom trawling activity, commercial species and benthic and demersal assemblages were studied integrating Vessel Monitoring System data (VMS), fishing logbook data and otter trawl samples in a mud volcano (MV) field of the Spanish margin of the Gulf of Cádiz (GoC) in 2011. High trawling activity was detected around Anastasya MV and between the Cád...

The Gulf of Cádiz is influenced by the collision of the Alborán Domain with the North African and South Iberian margins, which ultimately promotes hydrocarbon-rich fluid venting. Regarding oceanography, the effects of the Eastern North Atlantic Central Water, the Mediterranean Outflow Water and their interaction, strongly influence seabed topograph...

The Bay of Málaga is located in a high biodiversity and productivity area that harbours a wide variety of commercial species exploited by different fishing fleets. Benthic and demersal fauna from circalittoral soft bottoms have been studied using a benthic dredge (BD) (8 sampling stations) and an otter trawl (OT) (8 sampling stations on a seasonal...

A relationship between scleractinian cold-water corals and fluid venting submarine structures has been observed in Mediterranean and adjacent areas. Mud volcanoes and mud diapirs promote different substrate types for biological colonisation: from muddy bottoms with chemosynthesis-based communities and typical bathyal soft bottom fauna to hard botto...

The present study describes for the first time the spatial distribution of five macrourid species throughout the Mediterranean Sea and analyses depth, geographical and time-related trends regarding their abundance, biomass and mean fish weight. The data were collected as part of the MEDITS annual bottom trawl survey carried out by several European...

The holothurian Parastichopus tremulus, a species only know from the north-eastern Atlantic, is reported for the first time from the Mediterranean Sea. Five individuals of the species were collected in the vicinity of the Seco de los Olivos sea mount in May 2017 from a bottom trawl sample carried out during the MEDITS trawl survey. Scanning Electro...

Lesson learned in the ATLAS project regarding the challenges and opportunities in achieving “Good Environmental Status” in North Atlantic deep-seas.

Assessing environmental status in North Atlantic deep seas

Tagoro, the youngest submarine volcano of the Canary Islands, erupted in 2011 South of El Hierro Island. Pre-existing sea floor and inhabiting biological communities were buried by the newly erupted material, promoting the appearance of new habitats. The present study pursues to describe the first metazoans colonizing different new habitats formed...

The Pirabas Formation crops out in northern Brazil, spread discontinuously through the states of Pará, Maranhão and Piauí. It is one of the most fossiliferous geotectonic units in Brazil, filled by lower Miocene sediments that are correlated lithostratigraphically with the Caribbean Province. Information on fossil bryozoans from the Pirabas Formati...

Seasonal dynamics and preferential sedimentary habitats of commercial molluscs have been studied in soft bottoms within the limits of the Special Area of Conservation (SAC) “Calahonda” (S Spain). This SAC harbours a high diversity of invertebrate communities, and it is located in a very touristy area of the littoral of Malaga and within the limits...

Mud volcanoes are singular seafloor structures classified as ‘sensitive habitats’. Here we report on the sponge fauna from a field of eight mud volcanoes located in the Spanish margin of the northern Gulf of Cadiz (North-eastern Atlantic), at depths ranging from 380 to 1146 m. Thirty-eight beam-trawl samplings were conducted (covering over 61,000 m...

The Gulf of Cádiz margin is characterized by geological processes that control seabed bathymetry and promote hydrocarbon-rich fluid venting in areas where the Eastern North Atlantic Central Water and the Mediterranean Outflow Water influence the substrate types. Geological and oceanographic processes determine the distribution of a wide variety of...

The seabed characteristics, the oceanographic circulation and the geomorphology heterogeneity of the Gulf of Cádiz (mud volcanoes, diapiric ridges, channels, etc.) promote a wide variety of biological communities.

Mechanized dredging impact on discards was assessed along the northern Alboran Sea (W Mediterranean Sea). Data from 101 dredging operations were analysed for contrasting spatial and seasonal variability of damage, with the use of a three-level damage scale. 4.5% of discarded individuals displayed intermediate damage, whereas 11.3% displayed severe...

Molluscan assemblages of circalittoral and bathyal soft bottoms of the northern Alboran Sea were studied using an experimental otter trawl. Samples of fauna were collected from 190 hauls during four MEDITS surveys carried out in spring between 2012 and 2015 at depths ranging from 30 to 800 m. Measurements of water column variables (temperature and...

The smooth clam, Callista chione (Linnaeus, 1758), is a venerid bivalve widely appreciated in southern Spain where it represents the top commercial bivalve species in terms of landings and economic value. In this area, a total of 223 artisanal boats (68% of the artisanal fleet) are involved in shellfishing targeting bivalve molluscs, including the...

During the INDEMARES/CHICA 0610, 0211 and 0412 expeditions, carried out in the northern Spanish sector of the Gulf of Cádiz (Spain), samples were collected with a box-corer in 11 mud volcanoes and their adjacent bottoms. Chemoautotrophic communities were found in nine mud volcanoes. Among Decapoda, a rare eucalliacid, belonging to the genus Calliax...

Seamounts may promote the presence of vulnerable marine ecosystems (VMEs) worldwide. In the Alboran Sea (W Mediterranean Sea), the Chella Bank (locally known as “Seco de los Olivos”) is a seamount that covers ca. 100 km2 and is under the influence of different water masses in this important Atlanto-Mediterranean biogeographical transition zone. Dur...

Decapod assemblages associated with algal fronds and the underlying substratum in two different photophilous macroalgal beds dominated by the brown algae Halopteris scoparia were studied in the northwestern Alboran Sea, between July 2007 and April 2008. A total of 35 decapod species were found in the macroalgal beds, most of them inhabiting both st...

Diapirs and mud volcanoes (MVs) are formed by the migration and extrusion of fluids and mud to the seafloor, respectively. In the Gulf of Cádiz there are ca. 60 MVs and several diapirs with different environmental conditions and seepage activity. Previous studies, mainly on MVs, have demonstrated that the invertebrate fauna associated with these se...

The MEDWAVES (MEDiterranean out flow WAter and Vulnerable EcosystemS) cruise targeted areas under the potential influence of the MOW within the Mediterranean and Atlantic realms. These include seamounts where Cold-water corals (CWCs) have been reported but that are still poorly known, and which may act as essential “stepping stones” connecting faun...

The composition and structure of discard, as well as the damage caused to target and non-target species, was analyzed in 95 commercial fishing hauls carried out between March 2013 and March 2014 by the mechanized dredging fleet targeting wedge clam (Donax trunculus) in the northern Alboran Sea (southern Spain). A large proportion of the catch (ca....

Soft bottom molluscan assemblages from the Bay of Tunis have been studied in order to analyse their seasonality and trophic diversity in relation to environmental variables. A total of 147 species of molluscs was identified, with gastropods displaying the highest species richness and bivalves the highest abundances, and including five non-indigenou...

Seabed morphology, sub-bottom characteristics and benthic communities of the Hespérides volcanic complex, located in the continental slope of the Gulf of Cadiz, have been analyzed. The aim of this study is to characterize the morphological features, the geological processes and near-bottom water masses for understanding the relationships between th...

Article published in Quercus on the Natural Heritage of the Bay of Málaga ( southern Spain)

Mercator mud volcano has been explored by direct visual observations using a ROV at 350 to 370 m depth. Underwater images, taken mainly at the summit, have allowed characterizing the fluid venting environment, where different microforms, habitats and associated biota, with typical seepage components have been identified. Chemosynthetic bacterial co...

Habitat characterization using underwater images has been carried out in 4 mud volcanoes (Gazul, Almazán, St. Petersburg and Aveiro) and one mud volcano/diapir complex (Hespérides) located at the middle slope of the Spanish margin of the Gulf of Cádiz (360-1200m depth). A total of 126 species, mostly cnidarians, sponges, brachiopods, crustaceans an...

Seabed morphology, sub-bottom characteristics and benthic habitats of a sector of the Gulf of Cadiz continental slope have been analyzed. The aim is to recognize morphological features, geological processes and near-bottom water masses for understanding the relationships between the occurrence of fluid venting related edifices and their associated...

This paper evaluates the influence of habitat heterogeneity, inter-habitat connectivity and biogeograhical patterns in the context of a biodiversity hotspot in an Atlantic-Mediterranean marine transition area. We analyzed some biological and ecological aspects of molluscan assemblages inhabiting different habitats located in the northwestern Albora...

The analysis of a data set of multibeam bathymetry plus high resolution seismic and parametric profiles allow us to characterize the geomorphologic units on the Alboran Sea-floor as well as the evolution of morpho-sedimentary systems along the Pliocene and Quaternary, later than the main erosive Messinian event. Since the opening of the Gibraltar S...