Pulsed wind-driven control of phytoplankton biomass at a groundwater-enriched nearshore environment.

Along some Mediterranean coastal areas and other world regions, nutrient and chlorophyll concentrations often show gradient increases of up to one order of magnitude perpendicular to the coast. This nearshore stripe, extending a few hundred meters from the coast, is enriched by submarine groundwater discharges (SGD) containing elevated nutrient concentrations that may eventually sustain high biomass phytoplankton blooms. During a survey carried out in the summer of 2018, we examined the short-term (hours) variability of the phytoplankton biomass (measured as chlorophyll; Chl) in response to environmental changes associated with SGD and wind forcing in the nearshore waters of Palma Beach (Mediterranean Sea).

Pelagic diatoms communicate through synchronized beacon natural fluorescence signaling.

Communication between conspecific individuals is an essential part of life both in terrestrial and marine realms. Until recently, social behavior in marine phytoplankton was assumed to rely mainly on the secretion of a variety of infochemicals that allowed population-scale collective responses. Here, we demonstrate that pelagic diatoms also use Sun-stimulated fluorescence signals for synchronizing their behavior.

Method for the determination of preferential orientation of marine particles from laser diffraction measurements.

In situ laser diffractometry (LD) is increasingly used in oceanographic studies to estimate sediment transport, particle fluxes and to assess the concentration of marine phytoplankton. It enables an accurate characterization of the size distribution of suspended particles from the scattering signal produced by their interaction with a collimated laser beam. LD reliably reflects the sizes of suspensions dominated by nearly spherical particles; however, when complex particle morphologies dominate the suspension (e.

Collective sinking promotes selective cell pairing in planktonic pennate diatoms.

Finding a partner in an inherently unsteady 3-dimensional system, such as the planktonic marine environment, is a difficult task for nonswimming organisms with poor control over their orientation. We experimentally investigate the process of cell pairing in pennate marine diatoms and present field evidence of its occurrence in the ocean. We describe the mechanism as a 3-step process in which pennate diatoms () vertically reorient while sinking from surface turbulent waters to a more stable environment (i.

Settlement and post-settlement survival rates of the white seabream (Diplodus sargus) in the western Mediterranean Sea.

Survival during the settlement window is a limiting variable for recruitment. The survival is believed to be strongly determined by biological interactions and sea conditions, however it has been poorly investigated. We examined the settlement patterns related to relevant biotic and abiotic factors (i.

Advection by ocean currents modifies phytoplankton size structure.

Advection by ocean currents modifies phytoplankton size structure at small scales (1-10 cm) by aggregating cells in different regions of the flow depending on their size. This effect is caused by the inertia of the cells relative to the displaced fluid. It is considered that, at larger scales (greater than or equal to 1 km), biological processes regulate the heterogeneity in size structure.

Seasonal variation and sources of dissolved trace metals in Maó Harbour, Minorca Island.

The environmental conditions of semi-enclosed coastal water-bodies are directly related to the catchment, human activities, and oceanographic setting in which they are located. As a result of low tidal forcing, and generally weak currents, waters in Mediterranean harbours are poorly renewed, leading to quality deterioration. Here, we characterise the seasonal variation of trace metals (i.

Sunscreen products as emerging pollutants to coastal waters.

A growing awareness of the risks associated with skin exposure to ultraviolet (UV) radiation over the past decades has led to increased use of sunscreen cosmetic products leading the introduction of new chemical compounds in the marine environment. Although coastal tourism and recreation are the largest and most rapidly growing activities in the world, the evaluation of sunscreen as source of chemicals to the coastal marine system has not been addressed. Concentrations of chemical UV filters included in the formulation of sunscreens, such as benzophehone 3 (BZ-3), 4-methylbenzylidene camphor (4-MBC), TiO₂ and ZnO, are detected in nearshore waters with variable concentrations along the day and mainly concentrated in the surface microlayer (i.

Copper aerosols inhibit phytoplankton growth in the Mediterranean Sea.

Aerosol deposition plays an important role in climate and biogeochemical cycles by supplying nutrients to the open ocean, in turn stimulating ocean productivity and carbon sequestration. Aerosol particles also contain elements such as copper (Cu) that are essential in trace amounts for phytoplankton physiology but that can be toxic at high concentrations. Although the toxicity of Cu associated with aerosols has been demonstrated in bioassay experiments, extrapolation of these laboratory results to natural conditions is not straightforward.

Population genetic structure and connectivity of the harmful dinoflagellate Alexandrium minutum in the Mediterranean Sea.

The toxin-producing microbial species Alexandrium minutum has a wide distribution in the Mediterranean Sea and causes high biomass blooms with consequences on the environment, human health and coastal-related economic activities. Comprehension of algal genetic differences and associated connectivity is fundamental to understand the geographical scale of adaptation and dispersal pathways of harmful microalgal species. In the present study, we combine A.

Scientific management of Mediterranean coastal zone: a hybrid ocean forecasting system for oil spill and search and rescue operations.

The oil spill from Prestige tanker showed the importance of scientifically based protocols to minimize the impacts on the environment. In this work, we describe a new forecasting system to predict oil spill trajectories and their potential impacts on the coastal zone. The system is formed of three main interconnected modules that address different capabilities: (1) an operational circulation sub-system that includes nested models at different scales, data collection with near-real time assimilation, new tools for initialization or assimilation based on genetic algorithms and feature-oriented strategic sampling; (2) an oil spill coastal sub-system that allows simulation of the trajectories and fate of spilled oil together with evaluation of coastal zone vulnerability using environmental sensitivity indexes; (3) a risk management sub-system for decision support based on GIS technology.