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.

Risk Assessment and Characterization in Tuna Species of the Canary Islands According to Their Metal Content.

Bioaccumulation is the process by which living organisms accumulate substances, such as pesticides, heavy metals, and other pollutants, from their environment. These substances can accumulate in the organism's tissues over time, leading to potential health risks. Bioaccumulation can occur in both aquatic and terrestrial ecosystems, and can have a significant impact on the health of both humans and wildlife. The objective of this study is to find out if the concentrations of metals in the tuna species of the Canary Islands are suitable for human consumption and if they pose a health risk. Fifteen samples of Acanthocybium solandri, Katsuwonus pelamis, Thunnus albacares, Thunnus obesus and Thunnus thynnus present in canaries were analyzed. Ten grams of muscle were taken from each specimen and the metals Al, Cd, Cr, Cu, Fe, Li, Ni, Pb and Zn were determined by Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES). The tuna species that presented more metals with a higher concentration compared to the others was T. thynnus, reaching up to 100 times more than the other studied species in Fe content with 137.8 ± 100.9 mg/Kg, which may be due to the fact that it is the largest species that reaches ages of more than fifteen years. The species Thunnus thynnus should not be suitable for commercialization according to the current legislation on the concentrations of Cd in blue fish, since 75% of the specimens studied exceeded the concentration legislated for Cd. A total of 40% of the studied specimens of this this species exceeded the legislated values for the concentration of Pb in oily fish meat, so this species must be monitored to ensure that it does not pose a risk to human health.

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.

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.

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.

Assessments of metallic contents in rare cephalopods from the Canary Islands: relationships with depth habitat and body size.

This study investigated 20 elements in the muscle of 11 cephalopod species caught in the Canary Islands inhabiting from coastal to meso-bathypelagic habitats. Among them, trace element contents from large and elusive cephalopods such as Architeuthis dux, Taningia danae, Lepidoteuthis grimaldii, and Haliphron atlanticus were determined. Statistically significant differences in element concentration were found among class sizes and habitat. Large species that are inhabiting in deepest waters such as Loligo forbesii, A. dux, T. danae, H. atlanticus, and L. grimaldii showed a high load and variability in Fe and Al, while coastal species were characterized by a homogeneous element composition, being the Zn loads highest than other elements. Metal contents in large and elusive cephalopod species were dominated by Fe, Ni, Al, Zn, and Sr, with these species being able to carry important amounts of these elements to predators such as deep-diving odontocetes that reside around the Canary waters.

Limpets as bioindicators of element pollution in the coasts of Tenerife (Canary Islands).

Currently, there is an increase in marine pollution around the world; the most affected areas are the coastal ones since on the coast is where anthropogenic pollution first acts. Therefore, it is important to have natural bioindicators as organisms that indicate us in the first instance of this pollution. The main objective of the present research is to determine if Patella aspera and Patella candei crenata show statistical differences in their element content in contaminated areas of the Island of Tenerife and to verify if limpets can be good bioindicators of marine pollution by trace elements and non-essential elements. A total of 160 limpets were taken from 4 slopes of the Island of Tenerife in the Canary Islands. The samples were analyzed using the ICP-OES to obtain results of essential trace elements (Cr, Cu, Fe, Li, Ni, and Zn) and non-essential elements (Al, B, Cd, Pb, and V). P. aspera showed a higher concentration of elements than P. candei crenata, and it was in the Buenavista locality where alarming values of Cd 0.658 ± 0.124 mg/kg were observed for P. aspera. These two limpet species have been found to be useful as bioindicators of marine pollution based on the concentrations of metals especially for Cd and Cu.

Metal content in stranded pelagic vs deep-diving cetaceans in the Canary Islands.

The Canary Islands are home to many cetacean species, many of which are resident species. The present work aims to analyze, for the first time to the best of the authors' knowledge, the macronutrients, micronutrients and trace elements and toxic heavy metals in muscle and liver tissue of six species of stranded cetaceans in the Canary Islands. The study species were: Tursiops truncatus, Stenella frontalis, Delphinus delphis, Grampus griseus, Globicephala macrorynchus and Physeter macrocephalus. Statistical analysis studied the significant differences between the concentrations in muscle and liver tissues, with the differences in element content depending on the type of diving and length of the species. The results indicate that there are differences between muscle and liver for Ca, Cd, Co, Cu, K, Mg, Mn, Mo, Ni, Pb, Sr, V and Zn. Deep-diving animals differ in their concentrations of Cr, Cu, Mg, Mn, Mo, and Zn with respect to shallow-diving animals in muscle and in liver in Al, B, Cr, K, Mn and Mo. As for the differences between sex, the males present differences in their concentrations of B, Cd, K and Mg in muscle tissue with respect to the females, while differences in the liver were only detected in the Fe content. The study of the correlations shows that as the size of the animal increases, the concentration of Cd increases while the concentrations of Al, Cu and Zn decrease. The specimens foraging in shallower waters had the highest concentration of the macronutrient.

Differences in macroelements, trace elements and toxic metals between wild and captive-reared greater amberjack (Seriola dumerili) from the Mediterranean Sea.

Despite its legislative regulation and control, the quality and safety of aquatic products is somewhat questioned due to the potential bioaccumulation of pollutants. The elements (Al, B, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Mo, Na, Ni, Pb, Sr, V and Zn) were determined in the liver and muscle of wild and captive-reared Seriola dumerili with the aim of studying possible differences between origins, and sex-related variations. Additionally, the dietary intake of these elements derived from its consumption was also evaluated. Most of the elements and metals analyzed were accumulated to a higher extent in the liver of wild specimens whereas lower differences were observed in the muscle. Overall, the elements and metal composition of wild females strongly differed from that of captive-reared specimens probably related to the mobilization of nutrients for the spawning season in wild mature females, which were greater than their captive-reared counterparts.

Characterization of classes of mollusks in the East Atlantic according to their element content.

One hundred and ninety-two samples from six species of mollusks classified into the following taxonomic classes: Gastropoda (Patella aspera, Patella candei crenata), Bivalvia (Mytilus galloprovincialis, Ensis directus), and Cephalopoda (Abraliposis morisii, Pyroteuthis margatifera) were investigated. Samples were collected in the Atlantic Ocean (Canary Islands and Galicia). The concentrations of Al, B, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Mo, Na, Ni, Pb, Sr, V, and Zn were determined by ICP-OES. Statistical analysis verified that the classes of benthic organisms had the highest concentration of elements. However, the Cephalopoda class had the highest Cd (1.685 ± 0.929 mg/kg) and Pb (0.826 ± 1.104 mg/kg) content. On the other hand, the values obtained in this study were compared with studies conducted in other parts of the world to verify the environmental state of the Atlantic Ocean using the organisms studied as bioindicators.

Influence of Biometric and Seasonal Parameters on the Metal Content of Scomber colias in Northwestern African Waters.

Studies of the content of heavy metals and trace elements in fish and other marine organisms are of great importance to know the state of the marine ecosystem. This study has been carried out in northwestern African waters, Scomber colias being the target species, sampling a total of 345 specimens over 2 years. For the determination of metals and trace elements (Al, B, Cd, Cr, Cu, Fe, Li, Ni, Pb, V, and Zn) in the muscle, the ICP-OES (inductively coupled plasma optical emission spectrometry) was used. In the statistical study, the factors (oceanographic and maturity in the seasons, size of the specimens) were used. The samples sampled in the cold season that had high concentrations of metals may be due to the influence that African upwelling has on the Canary Islands. The metallic contents of our samples are lower than those found in the studies in Mauritania and Morocco due to the greater influence that upwelling has in these areas.