Metal concentrations in echinoderms: Assessing bioindicator potential and ecological implications.

This study investigates the concentrations of heavy metals and trace elements in five echinoderm species: Holothuria (Platyperona) sanctori, Arbacia lixula, Coscinasterias tenuispina, Ophioderma longicaudum, and Antedon bifida. Given their ecological significance and potential as a food source, understanding the presence and transfer of heavy metals in these species is crucial. Sampling was conducted in 2022 in Canary Islands. Analysis using ICP-OES revealed concentrations of Zn, Cd, Pb, Cu, Ni, Cr, and Fe in mg/kg. The results showed a consistent sequence of metals across all species, with Fe > Zn > Cu > Ni > Cr > Pb > Cd. Holothurians exhibiting the highest levels, followed by sea urchins. Starfish and brittle stars showed similar, lower concentrations, while crinoids exhibited the lowest levels, consistent with their filter-feeding behavior. The findings highlight the potential of holothurians as bioindicators for environmental pollutants. Understanding the role of these echinoderms as bioindicators is essential for assessing ecosystem health and informing conservation efforts in subtropical marine environments.

Environmental Factors Influencing Metal Concentrations in Scomber colias Along the Canary Islands.

A total of 140 specimens of Scomber colias were collected from the Canary archipelago waters during the first semester of 2021, with 20 samples from each of the seven main islands. After analyzing the concentrations of metals (Al, Zn, Cd, Pb, Fe, and Cu) with ICP-OES, significant variations were observed among islands, with specimens from Tenerife and Gran Canaria containing higher levels of Al, Cd, and Pb, while those from Lanzarote and Fuerteventura had elevated levels of Zn, Fe, and Cu. These differences are probably related to greater anthropogenic activity around Tenerife and Gran Canaria coasts, leading to higher pollution levels, and the influence of Saharan dust and African upwelling on Lanzarote and Fuerteventura, enriching the waters with nutrients. Specific management strategies to mitigate marine pollution and continuous monitoring are crucial to safeguard marine ecosystems and to ensure food security.

Impact of natural events on metal bioaccumulation in Anemonia sulcata.

Samples of Anemonia sulcata were collected in 2022 from different areas of the Canary Islands affected by different natural contamination sources, such sandstorms, submarine volcanic activity, continuous rainfall, upwelling and dinoflagellate blooms. Significant differences were observed between the zones for the metals and trace elements analyzed (Al, Zn, Cd, Pb, Ni, Co, Fe, B, Cu, Mg and Li). Anemones from volcanic areas showed higher levels of Cd, Pb and Ni. Individuals from sandstorm areas showed elevated levels of Al, Zn and Fe. Samples collected from areas affected by upwelling processes had higher concentrations of Cu, Mg and Li. Finally, the areas affected by dinoflagellates showed lower levels of Zn, Pb, Fe, Mg and Li. The study reveals how natural phenomena dramatically influence metal accumulation in A. sulcata, which is of great value for anticipating and managing potential problems associated with public health.

Comparative analysis of metal pollution in the Atlantic Ocean and Mediterranean Sea: insights from Anemonia sulcata study.

In this study, we investigated metal concentrations in Anemonia sulcata specimens from various locations in the Atlantic Ocean and the Mediterranean Sea. A total of 84 individuals were sampled from specific zones, and their tissue samples were processed for metal analysis using Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES). The results revealed notable differences in metal concentrations among the studied regions. The Atlantic Ocean and the Mediterranean Sea were found to have distinct patterns of marine pollution, influenced by a complex interplay of geographical, demographic, industrial, and environmental policy factors. Conversely, the semi-enclosed Mediterranean Sea has a lower natural dilution capacity, leading to the accumulation and prolonged presence of pollutants. Population density and industrial activities in coastal areas play a significant role in pollution disparities between the Mediterranean Sea and the Atlantic Ocean. The Mediterranean coasts, with higher population densities and intensive industrial operations, experience greater strain on marine ecosystems due to increased pollution sources. Additionally, environmental policies and management approaches differ between the two regions, contributing to variations in pollution response and regulation.

Metal content in Sardina pilchardus during the period 2014-2022 in the Canary Islands (Atlantic EC, Spain).

The contamination present in an organism varies depending on biological and oceanographic conditions, so monitoring the same species is of great importance to understand the state of the ecosystem. Fifteen specimens in Sardina pilchardus between 12 and 15 cm in total length were collected during the second half of January of each of the study years (2014, 2016, 2018, 2020 and 2022). Samples were analyzed with Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) to measure metals (Al, Cd, Cu, Fe, Li, Ni, Pb and Zn) in mg/Kg. There was a progressive decrease in Pb content over the period, with the highest concentration being obtained in 2014 (0.086 ± 0.065 mg/kg). Locally important oceanic-atmospheric events may occur in the study period that strongly impact the tissue composition of marine organisms. In this case, discontinuous trends were evident in some of the metal concentrations analyzed in the muscle of European sardine in the Canary Islands.

A Comparative Analysis of Sparisoma cretense in Island Environments: Unraveling Metal Accumulation Differences in the Canary Islands (Spain, NW African Waters).

This study investigates the impact of varying environmental conditions on the metal composition within the tissues of Sparisoma cretense, contributing to the understanding necessary to offer scientifically sound advice regarding the health status of this species. This knowledge extends beyond fishery production, encompassing implications for food security. The data span the years 2022 and 2023, encompassing both cold and warm climatic seasons. The concentrations of various metals, such as Al, Zn, Cd, Pb, Fe, and Cu, exhibited noteworthy variations across the islands, with significant increases recorded in 2023, particularly during the warm season. The intricate interplay between multiple factors shaped the availability of the analyzed elements in S. cretense. Factors such as rising temperatures during the warm season increased biological activity in marine ecosystems, seasonal fluctuations in weather conditions, water quality, and anthropogenic influences, all contributing to the observed variations in metal concentrations. Additionally, the geological composition of each island and the patterns of marine currents and sediment transport play pivotal roles in these differences. Comprehensive scientific research, monitoring, and environmental surveillance are essential for a holistic understanding of this variability and providing valuable insights for the conservation and management of marine ecosystems in the Canary archipelago.

Impact of the lockdown period during the COVID-19 pandemic on the metal content of the anemone Anemonia sulcata in the Canary Islands (CE Atlantic, Spain).

Anemones, specifically the species Anemonia sulcata, are cnidarians that serve as bioindicators in marine ecosystems, indicating the health of the environment and changes in environmental conditions. Monitoring anemone populations and studying their well-being and distribution provide valuable insights into marine ecosystem conditions. This study aimed to investigate the impact of the SARS-CoV-2 pandemic on the metal content of Anemonia sulcata. Over a six-year period (2017-2022), twenty specimens of Anemonia sulcata were collected in Tenerife, Spain. The results showed that in 2020, during the two-month lockdown in Spain from March to May when tourism was halted, A. sulcata exhibited the lowest concentrations of various metals studied (Al, Cd, Cu, Fe, Pb, and Zn). This finding suggests that the reduced anthropogenic pressure on the coast due to the absence of tourism significantly decreased pollution levels. Therefore, the study emphasizes the importance of promoting sustainable tourism worldwide. The research highlights that minimizing human impact on coastal areas through responsible tourism practices can effectively reduce pollution in marine ecosystems.

Monitoring different sources of marine pollution in the Canarian intertidal zone using Anemonia sulcata as a bioindicator.

Sea anemones have often been used as bioindicators of contamination because they are semisessile organisms that rarelly leave their niche, which is why they are conducive to affecting the ecosystem at the local level. The objective of this work is to determine whether the concentrations of heavy metals and trace elements in the anemone Anemonia sulcata vary depending on the source of contamination present. In 2021 seventy specimens were collected at five sampling points and fourteen specimens were collected in each point (Control Zone, Thermal Power Plant, Sewage Pipe, Harbour and Tourism) in 2021, on the island of Tenerife. All the areas studied characterized by a pollution condition had higher concentrations of metals and trace elements than the control area. The anemones from Harbour presented a greater number of metals with a higher concentration than the other study areas.

Metal and trace element concentrations in cetaceans worldwide: A review.

This bibliographical review is a compilation of different scientific publications that reported data on metal concentrations in the muscle tissue of different species of cetaceans from seas and oceans around the world. Forty-nine scientific articles were selected, published over a fifteen-year period (2006-2021) with data on heavy metals and trace elements. The different groups of cetaceans considered in this study generally presented low concentrations of Cd and Pb. The same cannot be said of Hg. The highest concentrations of Hg were found in the groups of false killer whales. Similarly, the use of these groups of cetaceans as bioindicators of metal contamination shows that the Mediterranean Sea is one of the most metallically contaminated areas in the world. This may be due to the closed nature of the Mediterranean Sea and to the fact that it is also a highly populated and industrialized area.

Structuring algae as buffers for heavy metals and trace elements in the Canary Islands intertidal habitat.

Coastal marine pollution from sewage pipes, waste discharges, can seriously affect intertidal organisms. Therefore, the aim of this study is to know if the structuring algae in the Canary intertidal can act as buffers against pollution. Samples were taken in the island of Tenerife (Canary Islands, Spain) from the intertidal water of Anemonia sulcata (anemone), Palaemon elegans (shrimp), Gongolaria abies-marina and Jania virgata (both structuring algae). Each sample was analyzed by Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) obtaining values for metals and trace elements (Al, Cd, Pb, Ca, K, Mg, Na, B, Ba, Ba, Co, Cr, Cu, Fe, Li, Mn, Mo, Ni, Sr, V and Zn). Higher concentrations were obtained in the two structuring algal species, with J. vigata having higher concentrations than G. abies-marina. Specimens of A. sulcata showed higher concentrations of trace elements and heavy metals than P. elegans. P. elegans y A. sulcata showed higher heavy metal concentrations and trace elements when algae were not present in the pool. Algae have a great buffering role in the intertidal of the Canary Islands.

Trace and macro elements concentrations in the blood and muscle of loggerhead turtles (Caretta caretta) from the Canary Islands, Spain.

Sea turtles can bioaccumulate heavy metals and trace elements over the years, therefore they can be used as bioindicators of pollution in the marine environment. The aim of this study was to analyze seventeen elements in blood and muscle of Caretta caretta from the Canary Islands and compare these concentrations in the two tissues. Thirteen blood samples and six muscle samples were collected from loggerhead turtles admitted to the Rescue Center of La Tahonilla. The samples were processed through microwave digestion and incineration. For the study of the data, a descriptive statistical analysis and a PERMANOVA were performed. All individuals in this study were juveniles (size <70 cm). The results of this study differ from previous studies on loggerhead sea turtles. All the elements analyzed were detected, with Na having the highest concentration in blood (75,379 ± 30,066 mg/kg) and muscle (222,626 ± 156,049 mg/kg). Statistically significant differences were found between the concentration of Al, B, Ba, Ca, Fe, K, Na, Sr, V and Zn in each tissue analyzed. Compared to other studies, a higher Cu concentration was found both in blood (252.9 ± 114.4 mg/kg) and in muscle (416 ± 247.8 mg/kg). This study has provided new data on pollutants in loggerhead sea turtles and increased the information available for different geographic areas, although more studies are needed to understand the effects and impact of these pollutants on sea turtles.

Analysis of metals and metalloid in commercial fish species from the Galapagos Marine Reserve: Toxicological and nutritional assessment.

Aquatic pollution derived from metal presence in the Galapagos Islands could affect biodiversity and human health. This research provide a baseline on food safety in commercial fish species of the Galapagos Islands. We sampled muscle tissue of pelagic (Acanthocybium solandri) and demersal (Caulolatilus affinis, Pontinus clemensi, Hyporthodus mystacinus, and Paralabrax albomaculatus) species. Metal and metalloid concentrations per species were analyzed by Inductively Coupled Plasma Optical Spectrometry (ICP-OES). According to the Food and Agriculture Organization (FAO) regulation none of the studied species should be ingested; and according to the European Food Safety Authority (EFSA) regulation, all the studied species were above the Maximum Allowable Concentration (MAC) for Cd. According to EFSA, C. affinis should not be commercialized. Finally, A. solandri, P. clemensi and H. mystacinus do not represent a human health risk since its Margen of Safety (MoS) < 1 for people of up to 100 kg of body weight.

Essential Metals and Trace Elements in Cereals and Their Derivatives Commercialized and Consumed in Cape Verde.

Cereals and their derivatives are basic foods in the human diet and a source of minerals, but the content of elements may vary depending on the type of cereal or its processing. The levels of Na, K, Ca, Mg, Fe, Cu, Zn, Mo, Co, and Mn have been determined in 126 samples of cereals and cereal derivatives (rice, corn gofio, corn flour, wheat flour, corn, and wheat) commercialized and consumed in Cape Verde using an inductively coupled plasma-optical emission spectrometer (ICP-OES) after a wet microwave digestion process. Some elements stand out in products such as corn gofio (K), wheat (Mg), and wheat flour (Fe). Negative correlations were found between Mo-Na and Na-Zn that could suggest interference between these elements. Bearing in mind the dietary intake evaluation and the guideline values provided by EFSA (European Food Safety Authority) or FAO (Food Authority Organization), the consumption of wheat (100 g/day) provides a notable contribution of Mo, Mn, Fe, and Mg. Considering the nutritional value of the analyzed essential and trace elements, the consumption of different cereals and their derivatives should be promoted.

Influence of Seminal Metals on Assisted Reproduction Outcome.

Increased levels of metal ions in human seminal fluid have a significant correlation with male fertility. Few publications explain the effect of metals in semen and their influence on assisted reproductive treatments. Semen parameters and the levels of twenty-two metals were measured in the seminal fluid of 102 men attended in a Reproductive Unit. Metals were determined by optical emission spectrophotometry. A statistical relationship was found between spermiogram and iron, which was lower than expected in pathological spermiograms (p = 0.032); zinc (p = 0.066), calcium (p = 0.047), and magnesium (p = 0.048) mean levels were higher in normozoospermics. More days of sexual abstinence correlates with higher seminal zinc (p = 0.001) and magnesium levels (p = 0.002). Lower vanadium values were found to be associated with higher fertilization rates (p = 0.039). Higher values of lead (p = 0.052) and vanadium (p = 0.032) were obtained in patients who did not reach 100% embryo cleavage rate. Aluminium (p = 0.042) and sodium (p = 0.002) were found in lower amounts associated with better blastocyst rates. The implantation rate shows an inverse association with women's age and iron and calcium content, compared to magnesium and sodium which presented a significant direct association with this percentage. A significant direct relationship was found between the positive evolution of pregnancy and the values of zinc (p = 0.004), calcium (p = 0.013), potassium (p = 0.002), and magnesium (p = 0.009). The study confirms that zinc, iron, calcium, sodium, aluminium, magnesium, vanadium, and lead have positive-negative effects on reproduction and support the analysis of metals in semen as a new line of study on male fertility with implications for reproductive outcomes.

Interdecadal variations of the mercury content in Scomber colias in Canary Islands.

Mercury is a very dangerous toxic metal that bioaccumulates very easily in organisms, and it migrates through the food web. The specimens studied in this study were Scomber colias. In the results obtained for the years 1973, 1992, and 2021, the concentration of mercury has been decreasing considerably over the decades, starting with 0.23 ± 0.04 mg/kg in 1973, and having less than half in 2021 with 0.11 ± 0.01 mg/kg. This may be due to the laws imposed by the countries against pollution and to a greater extent in the elimination of mercury; thanks to these measures it has been possible to reduce the concentration of mercury by half in S. colias. Otherwise, the conservation and availability of historical collections of living beings should be considered an unvalued source of information which could help to monitor legislation measures launched to ameliorate the human impact on the natural environment.

Fluoride Exposure from Soybean Beverage Consumption: A Toxic Risk Assessment.

The consumption of vegetable milk as a substitute for cow's milk has increased in recent years. Of all the vegetable beverages on the market, soy is the most widely consumed. Soy is exposed to contamination by different chemical elements during harvesting. In this study, the concentration of fluoride in soy beverages was analyzed. Fluoride is an element that in high concentrations can be toxic, causing dental and bone fluorosis. The aims of the study were (i) to analyze the fluoride concentration in 30 samples in the most popular brands (A-Brand, B-Brand, C-Brand) of soybean beverages by a fluoride ion selective potentiometer and (ii) to evaluate the toxicological risk derived from its consumption. The fluoride concentrations were 15.5 mg/L (A-Brand), 11.3 mg/L (B-Brand) and 8.5 mg/L (C-Brand). A consumption of 1 to 3 servings/day was established. One serving (200 mL) of soybean beverage offered a contribution percentage over the ADI (acceptable daily intake) for infants and children. Teenagers and adults did not exceed the ADI (10 mg/day). The consumption of soy beverages contributes significantly to the daily intake of fluoride, which could exceed the ADI with a consequent health risk. It is recommended to control the fluoride levels in the raw material and in the final product to assure the safety of these products.

The influence of the degassing phase of the Tagoro submarine volcano (Canary Islands) on the metal content of three species of cephalopods.

Underwater volcanic eruptions are a type of natural contamination that affect all marine organisms at a local level. These eruptions usually begin and end a degassing stage of the volcano that, although they do not affect the magnitude of magma emanation, affect organisms to a lesser degree locally, such as cephalopods that due to their metabolism and trophic level, are good bioindicators of contamination. A total of 180 samples of three species of cephalopods were collected for the study: sixty Sepia officinalis, sixty Octopus vulgaris and sixty Loligo vulgaris in the area of the submarine volcano in El Hierro, Tenerife and Lanzarote in the Canary Islands (twenty samples per species in each location), and the metal concentrations (Al, Cd, Cr, Cu, Fe, Li, Ni, Pb and Zn) in each of the samples were analyzed. All species showed significant differences for all metals in El Hierro compared to Tenerife and Lanzarote. All the analyzed species from El Hierro had higher concentrations of the nine studied metals, this is due to the fact that they were caught near the Tagoro submarine volcano, which at the time was in a state of degassing and discharged many metal-rich compounds.

Fluoride levels in river water from the volcanic regions of Cauca (Colombia).

Fluoride concentrations of 0.5 mg/L in drinking water are considered useful for dental caries prevention. However, fluoride concentrations higher than 1.2 mg/L in water can pose a risk of dental fluorosis due to high exposure to fluoride. The objective is to determine the fluoride concentration in water from aqueducts of different Colombian municipalities of Cauca (Popayán, Coconuco, and Puracé) to assess the fluoride dietary intake from the consumption of this water. A total of 66 water samples have been taken from Popayán, Coconuco, and Puracé. Fluoride content was determined by fluoride ion-selective electrode (ISE) potentiometry. The fluoride concentrations recorded in Coconuco and Puracé water were ≤ 0.002 mg/L. The mean fluoride content recorded in the Popayán water was 0.42 mg/L, with its highest concentration in Cauca River water (0.83 mg/L). Considering the admissible intake values, the water from Popayán confers remarkable fluoride intakes, especially in children with high percentages of contribution to the admissible daily intake (46.7% to 7- to 12-month children and 41.5% to 1- to 3-year children). The fluoride content in the water of Coconuco and Puracé does not reach an optimal value (< 0.5 mg/L) for the protective effect against dental caries, while the water of the main Cauca River basin does reach the optimal value. Likewise, the intake of fluoride from the consumption of the analyzed water does not confer any health risk. However, the implementation of monitoring systems for fluoride levels is recommended in order to safeguard the consumer's health.

Assessment of Toxic Metals (Al, Cd, Pb) and Trace Elements (B, Ba, Co, Cr, Cu, Fe, Mn, Mo, Li, Zn, Ni, Sr, V) in the Common Kestrel (Falco tinnunculus) from the Canary Islands (Spain).

The monitoring of trace elements and toxic metals in apical predators of the trophic chain provides data on the degree of contamination in ecosystems. The common kestrel is one of the most interesting raptors in this respect in the Canary Islands; therefore, the study of the levels of trace elements and toxic metals in this species is of much scientific value. The content of trace elements and toxic metals (B, Ba, Co, Cr, Cu, Fe, Mn, Mo, Li, Zn, Ni, Sr, V, Al, Cd, Pb) was determined in the liver, muscle, and feathers of 200 specimens of common kestrel carcasses (Falco tinnunculus canariensis) from Tenerife. Cr (0.82 ± 2.62 mg/kg), Cu (11.82 ± 7.77 mg/kg), and Zn (198.47 ± 520.80 mg/kg) are the trace elements that stand out in the feather samples; this may be due to their affinity for the pigments that give them their coloring. Li was noteworthy in the liver samples (8.470 ± 5.702 mg/kg). Pb stood out in the feathers (4.353 ± 20.645 mg/kg) > muscle (0.148 ± 0.095 mg/kg) > liver (0.187 ± 0.133 mg/kg). The presence of metals in feathers correlates with recent exposure and reflects environmental contamination. When using raptor feathers as indicators of metal contamination, it is important to know what the levels of each metal signify. The analysis of the different tissues and organs of raptors, such as the common kestrel, provides valuable information on the degree of environmental contamination of the ecosystem in which it lives. Gender was not an influencing factor in this study.

Metal and metalloids concentration in Galapagos fish liver and gonad tissues.

The Galapagos Islands are one of the best-preserved archipelagos in the world. We sampled individuals of six demersal and three pelagic species. The metal concentration of liver and gonad tissues were analyzed by Inductively Coupled Plasma Optical Spectrometry. Findings suggest none of the pelagic species showed metallic concentrations that could pose a risk to their health or reproductive capacity. S. violacea and P. clemensi Zn levels were higher in liver than in gonads, indicating that these species could be in their reproduction period. Zn risk toxicity for the study species is negligible. High concentrations of Cd were found in the liver of C. princeps, C. affinis and P. albomaculatus which could cause morphological and physiological alterations. We hypothesize that the high metal concentrations found in the demersal species could come from the volcanism of the islands, since no major sources of anthropogenic metal contamination can be found in the archipelago.