Sunscreens have been shown to give the most effective protection for human skin from ultraviolet (UV) radiation. Chemicals from sunscreens (i.e., UV filters) accumulate in the sea and have toxic ...effects on marine organisms. In this report, we demonstrate that photoexcitation of inorganic UV filters (i.e., TiO2 and ZnO nanoparticles) under solar radiation produces significant amounts of hydrogen peroxide (H2O2), a strong oxidizing agent that generates high levels of stress on marine phytoplankton. Our results indicate that the inorganic oxide nanoparticle content in 1 g of commercial sunscreen produces rates of H2O2 in seawater of up to 463 nM/h, directly affecting the growth of phytoplankton. Conservative estimates for a Mediterranean beach reveal that tourism activities during a summer day may release on the order of 4 kg of TiO2 nanoparticles to the water and produce an increment in the concentration of H2O2 of 270 nM/day. Our results, together with the data provided by tourism records in the Mediterranean, point to TiO2 nanoparticles as the major oxidizing agent entering coastal waters, with direct ecological consequences on the ecosystem.
This study quantifies the concentration of trace metals in coastal marine macrophytes (seagrasses, Chlorophytae, Phaeophytae and Rhodophytae). We do so by compiling, from 155 peer review research ...articles, almost 23,000 estimates of trace metals (As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb and Zn) contents in natural populations of marine macroalgae and seagrasses distributed worldwide. The objective was to explore the global distribution of concentrations of these metals in marine macrophytes, provide an estimate of their average and range in its tissues and to identify hotspots of coastal pollution. Our results reveal Phaeophytae as the group with the largest accumulation capacity and tolerance to elevated concentrations of metals regardless the species and the location. The mapping of geographic distribution of metal accumulation in marine macrophytes identifies some coastal areas as hotspots of trace metal contamination, where concentrations could reach levels up to 600 times higher than the mean.
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•A global dataset of trace metal concentration in marine macrophyte was compiled.•Phaeophytae can accumulate elevated concentrations of metals.•Hotspots of metal contamination have been identified in coastal areas worldwide.•Hotspots are mainly caused by anthropogenic activities.
Antarctica plays a fundamental role in the Earth's climate, oceanic circulation and global ecosystem. It is a priority and a scientific challenge to understand its functioning and responses under ...different scenarios of global warming. However, extreme environmental conditions, seasonality and isolation hampers the efforts to achieve a comprehensive understanding of the physical, biological, chemical and geological processes taking place in Antarctica. Here we present unmanned aerial vehicles (UAVs) as feasible, rapid and accurate tools for environmental and wildlife research in Antarctica. UAV surveys were carried out on Deception Island (South Shetland Islands) using visible, multispectral and thermal sensors, and a water sampling device to develop precise thematic ecological maps, detect anomalous thermal zones, identify and census wildlife, build 3D images of geometrically complex geological formations, and sample dissolved chemicals (< 0.22 µm) waters from inaccessible or protected areas.
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.e. 53.6-577.5 ng L⁻¹ BZ-3; 51.4-113.4 ng L⁻¹ 4-MBC; 6.9-37.6 µg L⁻¹ Ti; 1.0-3.3 µg L⁻¹ Zn). The presence of these compounds in seawater suggests relevant effects on phytoplankton. Indeed, we provide evidences of the negative effect of sunblocks on the growth of the commonly found marine diatom Chaetoceros gracilis (mean EC₅₀ = 125±71 mg L⁻¹). Dissolution of sunscreens in seawater also releases inorganic nutrients (N, P and Si forms) that can fuel algal growth. In particular, PO₄³⁻ is released by these products in notable amounts (up to 17 µmol PO₄³⁻g⁻¹). We conservatively estimate an increase of up to 100% background PO₄³⁻ concentrations (0.12 µmol L⁻¹ over a background level of 0.06 µmol L⁻¹) in nearshore waters during low water renewal conditions in a populated beach in Majorca island. Our results show that sunscreen products are a significant source of organic and inorganic chemicals that reach the sea with potential ecological consequences on the coastal marine ecosystem.
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. This study provides observational evidence of the negative effect of aerosols containing high Cu concentrations on marine phytoplankton over a vast region of the western Mediterranean Sea. Direct aerosol measurements were combined with satellite observations, resulting in the detection of significant declines in phytoplankton biomass after atmospheric aerosol events characterized by high Cu concentrations. The declines were more evident during summer, when nanoflagellates predominate in the phytoplankton population and stratification and oligotrophic conditions prevail in the study region. Together with previous findings concerning atmospheric Cu deposition, these results demonstrate that the toxicity of Cu-rich aerosols can involve large areas of the world’s oceans. Moreover, they highlight the present vulnerability of oceanic ecosystems to Cu-rich aerosols of anthropogenic origins. Because anthropogenic emissions are increasing, large-scale negative effects on marine ecosystems can be anticipated.
Sunscreen is released into the marine environment and is considered toxic for marine life. The current analytical methods for the quantification of sunscreen are mostly specific to individual ...chemical ingredients and based on complex analytical and instrumental techniques. A simple, selective, rapid, reproducible and low-cost spectrophotometric procedure for the quantification of commercial sunscreen in seawater is described here. The method is based on the inherent properties of these cosmetics to absorb in the wavelength of 300-400 nm. The absorption at 303 nm wavelength correlates with the concentration of most commercial sunscreens. This method allows the determination of sunscreens in the range of 2.5-1500 mg L-1, it requires no sample pretreatment and offers a precision of up to 0.2%. The spectrophotometric method was applied to quantify sunscreen concentrations at an Atlantic Beach with values ranging from 10 to 96.7 mg L-1 in the unfiltered fraction and from the undetectable value to 75.7 mg L-1 in the dissolved fraction. This method is suggested as a tool for sunscreen quantifications in environmental investigations and monitoring programs.
Iron plays a crucial role in the high-nutrient, low-chlorophyll Southern Ocean regions, promoting phytoplankton growth and enhancing atmospheric carbon sequestration. In this area, iron-rich ...Antarctic krill (Euphausia superba) and baleen whale species, which are among their main predators, play a large role in the recycling of iron. However, penguins have received limited attention despite their representing the largest seabird biomass in the southern polar region. Here, we use breeding site guano volumes estimated from drone images, deep learning-powered penguin census, and guano chemical composition to assess the iron export to the Antarctic waters from one of the most abundant penguin species, the Chinstrap penguin (Pygoscelis antarcticus). Our results show that these seabirds are a relevant contributor to the iron remobilization pool in the Southern Ocean. With an average guano concentration of 3 mg iron g
, we estimate that the Chinstrap penguin population is recycling 521 tonnes iron yr
, representing the current iron contribution half of the amount these penguins were able to recycle four decades ago, as they have declined by more than 50% since then.
Studies detailing the environmental impact of sunscreen products on coastal ecosystems are considered a high priority. In the present study, we have determined the release rate of dissolved trace ...metals (Al, Cd, Cu, Co, Mn, Mo, Ni, Pb, and Ti) and inorganic nutrients (SiO2, P-PO4 3–, and N-NO3 –) from a commercial sunscreen in seawater, and the role of UV radiation in the mobilization of these compounds. Our results indicate that release rates are higher under UV light conditions for all compounds and trace metals except Pb. We have developed a kinetic model to establish the release pattern and the contribution to marine coastal waters of dissolved trace metals and inorganic nutrients from sunscreen products. We conservatively estimate that sunscreen from bathers is responsible for an increase of dissolved metals and nutrients ranging from 7.54 × 10–4 % for Ni up to 19.8% for Ti. Our results demonstrate that sunscreen products are a significant source of metals and inorganic nutrients to coastal waters. The normally low environmental concentrations of some elements (e.g., P) and the toxicity of others (e.g., Pb) could be having a serious adverse effect on marine ecology in the Mediterranean Sea. This risk must not be ignored.
Con este artículo se continúa la exploración de las funciones del lenguaje académico en la lengua de señas colombiana (LSC), realizada por los mismos autores. El propósito en esta ocasión es ...presentar las características de la descripción física en LSC, tal como aparece en textos producidos por informantes sordos basándose en textos en español escrito. Se encuentra que, en la descripción física, más que en funciones anteriormente estudiadas, los textos en señas permiten describir las entidades de forma muy clara, acercándose a lo que los textos hablados y escritos consiguen principalmente a través de la multimedia. Se pueden identificar también en ellos las diversas nociones semántico-gramaticales presentes en textos similares en español. Los señantes recurren constantemente a préstamos del español a través de la ortografía manual, a veces para llenar una laguna léxica, otras para ayudar a los niños a reconocer conceptos en la lengua escrita.
Remote-sensing ocean colour studies have already been used to determine coastal water quality, coastal biodiversity, and nutrient availability. In recent years, Unmanned Aerial Vehicles (UAVs) ...equipped with multispectral sensors, originally designed for agriculture applications, have also enabled water-quality studies of coastal waters. However, since the sea surface is constantly changing, commonly used photogrammetric methods fail when applied to UAV images captured over water areas. In this work, we evaluate the applicability of a five-band multispectral sensor mounted on a UAV to derive scientifically valuable water parameters such as chlorophyll-a (Chl-a) concentration and total suspended solids (TSS), including a new Python workflow for the manual generation of an orthomosaic in aquatic areas exclusively based on the sensor’s metadata. We show water-quality details in two different sites along the Maltese coastline on the centimetre-scale, improving the existing approximations that are available for the region through Sentinel-3 OLCI imagery at a much lower spatial resolution of 300 m. The Chl-a and TSS values derived for the studied regions were within the expected ranges and varied between 0 to 3 mg/m3 and 10 to 20 mg/m3, respectively. Spectral comparisons were also carried out along with some statistics calculations such as RMSE, MAE, or bias in order to validate the obtained results.
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