Lázaro Marín-Guirao

• PhD in Biological Sciences
• Researcher at Instituto Español de Oceanografia

The Mar Menor is a hypersaline coastal lagoon in the southeast of Spain, which has experienced several eutrophication episodes in recent years. In 2022, an area of milky white turbid water appeared covering about 10% of its surface, and it has been there ever since. A comprehensive field research was set up to assess the origin of this possible whi...

The coastline is one of the most densely populated and exploited areas globally, positioning it as a "vanguard system" for assessing the impacts of global change. This status has led to the development of numerous indicators that provide insights into its ecological condition and the human pressures it faces. However, few studies directly evaluate...

Marine Heat Waves (MHWs) occurrence has been increasing in the Mediterranean Sea. The effects of field simulated MHWs of different intensity (medium and high temperature) on the transcriptome expression of the endemic seagrass Posidonia oceanica were evaluated considering different origins of the plant. The aim of the study was reached through a co...

The implementation of large-scale seagrass monitoring programmes (e.g. EU Marine Strategy Framework Directive) requires protocols and methodologies to provide reliable and replicable habitat quality assessments over broad geographical areas. As new platforms emerge and artificial intelligence evolves, the potential of optical remote sensing to moni...

: Large scale monitoring programs of Posidonia oceanica require novel techniques that allow for the effective and replicable assessment of meadow environmental status. In this context, shallow water remote sensing emerges as a key tool, capable of addressing one of the main indicators of habitat status: the characterization and evolution of meadow...

Seagrasses' ability to store information after exposure to stress (i.e. stress memory) and to better respond to further stress (i.e. priming) have recently been observed, although the temporal persistence of the memory and the mechanisms for priming induction remain to be defined. Here, we explored three priming strategies in Posidonia oceanica see...

Water desalination has become an important process to cope with water scarcity in the Mediterranean basin; however, the endemic seagrass Posidonia oceanica may be susceptible to high-salinity brines derived from this industry. To understand how brine affects metabolic processes in P. oceanica, transplantation experiments were performed in two sites...

We present chromosome-level genome assemblies from representative species of three independently evolved seagrass lineages: Posidonia oceanica, Cymodocea nodosa, Thalassia testudinum and Zostera marina. We also include a draft genome of Potamogeton acutifolius, belonging to a freshwater sister lineage to Zosteraceae. All seagrass species share an a...

The surfgrass Phyllospadix scouleri grows in highly productive meadows along the Pacific coast of North America. This region has experienced increasingly severe marine heatwaves (MHWs) in recent years. Our study evaluated the impact of consecutive MHWs, simulated in mesocosms, on essential ecophysiological features of P. scouleri. Overall, our find...

Desalination has been proposed as a global strategy for tackling freshwater shortage in the climate change era. However, there is a concern regarding the environmental effects of high salinity brines discharged from desalination plants on benthic communities. In this context, seagrasses such as the Mediterranean endemic and ecologically important P...

Introduction Light gradients are ubiquitous in marine systems as light reduces exponentially with depth. Seagrasses have a set of mechanisms that help them to cope with light stress gradients. Physiological photoacclimation and clonal integration help to maximize light capture and minimize carbon losses. These mechanisms can shape plants minimum li...

Introduction The rapid increase in sea-water temperatures and frequency of extreme thermal events have amplified the risk of functional extinction of Mediterranean species such as the endemic long-lived seagrass Posidonia oceanica. Because of the valuable ecological functions and ecosystem services the species provides, understanding the life-stage...

Adaptation to local conditions is known to occur in seagrasses; however, knowledge of the genetic basis underlying this phenomenon remains scarce. Here, we analysed Posidonia oceanica from six sites within and around the Stagnone di Marsala, a semi-enclosed coastal lagoon where salinity and temperature exceed the generally described tolerance thres...

In the last three decades, quantitative approaches that rely on organism traits instead of taxonomy have advanced different fields of ecological research through establishing the mechanistic links between environmental drivers, functional traits, and ecosystem functions. A research subfield where trait-based approaches have been frequently used but...

Seagrasses comprise the only submerged marine angiosperms, a feat of adaptation from three independent freshwater lineages within the Alismatales. These three parallel lineages offer the unique opportunity to study convergent versus lineage-specific adaptation to a fully marine lifestyle. Here, we present chromosome-level genome assemblies from a r...

The continuous worldwide seagrasses decline calls for immediate actions in order to preserve this precious marine ecosystem. The main stressors that have been linked with decline in seagrasses are 1) the increasing ocean temperature due to climate change and 2) the continuous inputs of nutrients (eutrophication) associated with coastal human activi...

In coastal lagoons, marine benthic macrophyte meadows can be an important element in the resistance to eutrophication of the ecosystem, as they can function as temporary nitrogen sinks, limiting the availability of this nutrient for opportunistic organisms. The role of nitrogen sinks for two dominant macrophyte species of Mediterranean coastal lago...

In the Mediterranean, anthropogenic pressures (specifically those involving nutrient loads) have been progressively moved to deeper off-shore areas to meet current policies dealing with the protection of marine biodiversity (e.g., European Directives). However, conservation efforts devoted to protecting Posidonia oceanica and other vulnerable marin...

DNA methylation (DNAm) has been intensively studied in terrestrial plants in response to environmental changes, but its dynamic changes in a temporal scale remain unexplored in marine plants. The seagrass Posidonia oceanica ranks among the slowest-growing and longest-living plants on Earth, and is particularly vulnerable to sea warming and local an...

Very small-sized shoots of the Mediterranean seagrass Posidonia oceanica, defined as “bonsai” shoots, were found in areas with most intense CO2 emissions and low pH associated with four vents systems off Panarea island (Aeolian Archipelago, Sicily, Southern Tyrrhenian Sea). Bonsai shoots were sampled in September 2021 and October 2022: Bottaro crat...

The surfgrass Phyllospadix scouleri constitutes highly productive meadows along the Pacific coast of North America – a region that has been increasingly affected by severe marine heatwaves (MHWs) in recent years. Our study assessed the effects of consecutive MHWs simulated in mesocosms on critical ecophysiological descriptors of P. scouleri. Genera...

Human- and nature-induced hypersaline conditions in coastal systems can lead to profound alterations of the structure and vitality of seagrass meadows and their socio-ecological benefits. In the last two decades, recent research efforts (>50 publications) have contributed significantly to unravel the physiological basis underlying the seagrass–hype...

In seagrass sediments, lucinid bivalves and their chemoautotrophic bacterial symbionts consume H2S, relying indirectly on the plant productivity for the presence of the reduced chemical. Additionally, the role of lucinid bivalves in N provisioning to the plant (through N2 fixation by the symbionts) was hypothesized. Thus, lucinids may contribute to...

Seagrass ecosystems usually respond in a nonlinear fashion to increasing pressures and environmental changes. Feedback mechanisms operating at the ecosystem level and involving multiple interactions among the seagrass meadow, its associated community and the physical environment are known to play a major role in such nonlinear responses. Phenotypic...

The intensification of anomalous events of seawater warming and the co-occurrence with local anthropogenic stressors are threatening coastal marine habitats, including seagrasses, which form extensive underwater meadows. Eutrophication highly affects coastal environments, potentially summing up to the widespread effects of global climate changes. I...

Marine heat waves (MHWs), prolonged discrete anomalously warm water events, have been increasing significantly in duration, intensity and frequency all over the world, and have been associated with a variety of impacts including alteration of ecosystem structure and function. This study assessed the effects of current and future MHWs on the Mediter...

Seawater warming and increased incidence of marine heatwaves (MHW) are threatening the integrity of coastal marine habitats including seagrasses, which are particularly vulnerable to climate changes. Novel stress tolerance-enhancing strategies, including thermo-priming, have been extensively applied in terrestrial plants for enhancing resilience ca...

A better understanding of species and population responses to thermal stress is critical to predict changes in their distribution under warming scenarios. Seagrasses are a unique group of marine plants that play fundamental roles in marine environments and provide vital ecosystem services. Nevertheless, previous studies on seagrass thermal toleranc...

The role of DNA methylation and its interaction with gene expression and transcriptome plasticity is poorly understood, and current insight comes mainly from studies in very few model plant species. Here, we study gene body DNA methylation (gbM) and gene expression patterns in ecotypes from contrasting thermal environments of two marine plants with...

The potential negative influence of the seaweed Caulerpa prolifera on the seagrass Cymodocea nodosa was explored in a Mediterranean coastal lagoon (Mar Menor, Spain) where the alga suddenly and rapidly spread four decades ago. An extensive field sampling was carried out across the lagoon to characterise the distribution and abundance of both macrop...

Seagrasses are valuable sources of food and habitat for marine life and are one of Earth's most efficient carbon sinks. However, they are facing a global decline due to ocean warming and eutrophication. In the last decade, with the advent of new technology and molecular advances, there has been a dramatic increase in the number of studies focusing...

Coastal oceans are particularly affected by rapid and extreme environmental changes with dramatic consequences for the entire ecosystem. Seagrasses are key ecosystem engineers or foundation species supporting diverse and highly productive ecosystems along the coastline that are particularly susceptible to fast environmental changes. In this context...

Citation: Pazzaglia, J.; Nguyen, H.M.; Santillán-Sarmiento, A.; Ruocco, M.; Dattolo, E.; Marín-Guirao, L.; Procaccini, G. The Genetic Component of Seagrass Restoration: What We Know and the Way Forwards. Water 2021, 13, 829.

Seagrass meadows are disappearing at rates comparable to those reported for mangroves, coral reefs, and tropical rainforests. One of the main causes of their decline is the so-called cultural eutrophication, i.e., the input of abnormal amounts of nutrients derived from human activities. Besides the impact of eutrophication at a local scale, the occ...

Under unfavourable conditions, clonal plants benefit from physiological integration among ramets, sharing resources and information. Clonal integration can buffer against environmental changes and lets the plant clone work as a ‘macro’ organism. Molecular signals that regulate this phenomenon are completely unknown in marine plants. Here we present...

El presente artículo sintetiza la situación de la laguna costera del Mar Menor en relación con los nutrientes, centrándose especialmente en el periodo anterior a la DANA de septiembre de 2019 y en la evolución de dicha situación tras la DANA, con particular atención al episodio de mortandad masiva ocurrido a mediados de octubre de 2019. Se presenta...

While thermal priming and the relative role of epigenetic modifications have been widely studied in terrestrial plants, their roles remain unexplored in seagrasses so far. Here, we experimentally compared the ability of two different functional types of seagrass species, dominant in the Southern hemisphere, climax species Posidonia australis and pi...

Se analiza la evolución del ecosistema marino de la laguna costera del Mar Menor en relación con el episodio de mortandad masiva que se registró en octubre de 2019, las causas de la crisis ecológica del Mar Menor y se apuntan algunas consideraciones en relación con la recuperación del Mar Menor

Introduction: Gene-expression patterns and their upstream regulatory mechanisms (e.g. epigenetic) are known to modulate plant acclimatability and thus tolerance to heat stress. Within species, thermal plasticity (i.e. temperature-sensitive phenotypic plasticity) and differential thermo-tolerance are recognized among different genotypes, development...

A severe degradation of Mar Menor has been caused by the eutrophication process due to the excess of nutrients, degradation that the lagoon has been suffering since the 2016 eutrophic event and that has been aggravated by the nutrient and sediments contained in the runoff caused by the subtropical jet stream of September 2019

The invasive seaweed Caulerpa cylindracea has shown a reduced ability to invade healthy Posidonia oceanica meadows by penetrating only meadow margins in early invasion stages in the western Mediterranean Sea. However, the long-term interaction with invasive seaweed could deteriorate the structure of meadows by diminishing their initial resistance t...

Whole transcriptome analysis of the seagrass Posidonia oceanica (L.) Delile, 1813 was performed under control and acute low-light conditions (LL). The study explored the molecular response of the shoot-apical meristem (SAM) in comparison with leaf tissue, which is classically used in this kind of studies. Photo-physiological and morphological respo...

In shallow coastal ecosystems, as for example coastal lagoons, macrophytes account for high biomasses and productivity (Sand-Jensen 1975, Viaroli et al. 1996) being able to play a major role in the biogeochemical cycles of nutrients (Romero et al. 2006, Touchette and Burkholder 2000). When strong inputs of nutrients occur, due to natural and/or ant...

The Mediterranean Sea is particularly vulnerable to warming and the abrupt declines experienced by the endemic Posidonia oceanica populations after recent heatwaves have forecasted severe consequences for the ecological functions and socio‐economical services this habitat forming species provides. Nevertheless, this highly clonal and long‐lived spe...

The knowledge of how molecular functions vary in relation to developmental and environmental cues within and among seagrass leaves is scarce in comparison with terrestrial angiosperms. This strongly limits the mechanistic understanding of photosynthetic development and light acclimation processes in seagrasses, besides having fundamental methodolog...

Abstract Increased plant mortality in temperate seagrass populations has been recently observed after summer heatwaves, although the underlying causes of plant death are yet unknown. The potential energetic constrains resulting from anomalous thermal events could be the reason that triggered seagrass mortality, as demonstrated for benthic invertebr...

Global warming is emerging as one of the most critical threats to terrestrial and marine species worldwide. This study assessed the effects of simulated warming events in culture on two seagrass species, Posidonia oceanica and Cymodocea nodosa, which play a key role in coastal ecosystems of the Mediterranean Sea. Changes in fatty acids as key metab...

Seagrasses are key marine foundation species, currently declining due to the compounded action of global and regional anthropogenic stressors. Eutrophication has been associated with seagrass decline, while grazing has been traditionally considered to be a natural disturbance with a relatively low impact on seagrasses. In the recent years, this ass...

Posidonia oceanica meadows are facing global threats mainly due to episodic heat waves. In a mesocosm experiment, we aimed at disentangling the molecular response of P. oceanica under increasing temperature (20 °C–32 °C). The experiment was carried out in spring, when heat waves can potentially occur and plants are putatively more sensitive to heat...

Seagrasses are globally declining and often their loss is due to synergies among stressors. We investigated the interactive effects of eutrophication and burial on the Mediterranean seagrass, Posidonia oceanica. A field experiment was conducted to estimate whether shoot survival depends on the interactive effects of three levels of intensity of bot...

Sexual reproduction in predominantly clonal marine plants increases recombination favoring adaptation and enhancing species resilience to environmental change. Recent studies of the seagrass Posidonia oceanica suggest that flowering intensity and frequency are correlated with warming events associated with global climate change, but these studies h...

Seawater warming associated to the ongoing climate change threatens functioning and survival of keystone coastal benthic species such as seagrasses. Under elevated temperatures, the production of reactive oxygen species (ROS) is increased and plants must activate their antioxidant defense mechanisms to protect themselves from oxidative damage. Here...

The endemic Mediterranean seagrass Posidonia oceanica is highly threatened by the increased frequency and intensity of heatwaves. Meadows of the species offer a unique opportunity to unravel mechanisms marine plants activate to cope transient warming, since their wide depth distribution impose divergent heat-tolerance. Understanding these mechanism...

Seagrasses form extensive meadows in shallow coastal waters and are among the world's most productive ecosystems. Seagrasses can produce both clonally and sexually, and flowering has long been considered infrequent, but important for maintaining genetically diverse stands. Here we investigate the molecular mechanisms involved in flowering of the se...

The Mediterranean endemic seagrass Posidonia oceanica is generally regarded as a stenohaline species, highly sensitive to salinity increments; however, in a few particular cases, natural populations can grow under salinity levels above its normal threshold of tolerance. One such case is a population of P. oceanica in the southeastern coastal region...

Here we present the results of a multiple organizational level analysis conceived to identify acclimative/adaptive strategies exhibited by the seagrass Posidonia oceanica to the daily fluctuations in the light environment, at contrasting depths. We assessed changes in photophysiological parameters, leaf respiration, pigments, and protein and mRNA e...

Phenotypic differences among populations of the same species reflect selective responses to ecological gradients produced by variations in abiotic and biotic factors. Moreover, they can also originate from genetic differences among populations, due to a reduced gene flow. In this study, we examined the extent of differences in photo-acclimative tra...

Oxidative stress response of P. oceanica and C. nodosa to short-term heat stress Posidonia oceanica and Cymodocea nodosa are marine angiosperms widely distributed in the Mediterranean Sea. As habitat builders, they have crucial importance for coastal ecosystems; however because of human activities and environmental changes populations are in regres...

The increase in extreme heat events associated to global warming threatens seagrass ecosystems, likely by affecting key plant physiological processes such as photosynthesis and respiration. Understanding species’ ability to acclimate to warming is crucial to better predict their future trends. Here, we study tolerance to warming in two key Mediterr...