The multistressor effect of pH reduction, microplastic and lanthanum on sea urchin Arbacia lixula.

pH reduction (Low pH), microplastic (MP), and lanthanum (La) are substantial stressors due to their increasing trends in marine ecosystems and having adverse effects on marine species. This study investigates the single and combined effects of those stressors (Low pH: 7.45, polyethylene MP: 26 μg L, and La: 9 μg L) on the physiology and histology of sea urchin Arbacia lixula.

Assessment of Be-7, Pb-210 and Po-210 Activities in Airborne Particulate Matter Over Istanbul, Türkiye.

Airborne particulate matter is one of the air pollutants which can have detrimental health effects in the human body. Radionuclides adsorb onto air particles and make their way to humans primarily through inhalation. Naturally-occurring radionuclides, Pb and Po, are of notable health concern due to their relatively elevated ingestion and inhalation doses.

Po-210 activity concentrations in wild and farmed fish from the Aegean Sea and Sea of Marmara and dose assessment to consumers.

Polonium (Po) is the major contributor (with approximately 90%) to the radiation dose from radionuclides contained in the human diet, and it is mostly associated with seafood. This study presents Po activity concentrations in the tissues of 16 fish species from the Aegean Sea and Sea of Marmara. Among all species investigated, the highest Po activity concentration was 4450 ± 33 Bq kg dry weight (dw) in the digestive tract of anchovy (Engraulis encrasicolus), and the lowest Po activity concentration was 1.

The combined effects of polyethylene microplastics and benzoanthracene on Manila clam Ruditapes philippinarum.

Microplastic (MP) toxicity has recently been explored in various marine species. Along with the toxicity of plastics polymer itself, additional substances or pollutants that are absorbed onto it may also be harmful. In the present study, we investigated the combined impacts of polyethylene microplastics (PE MPs) and an organic pollutant (Benzo(a)anthracene, BaA) on Manila clam Ruditapes philippinarum during a one-week exposure.

Physiological and gene expression responses of the mussel Mytilus galloprovincialis to low pH and low dissolved oxygen.

The prevalence and frequency of hypoxia events have increased worldwide over the past decade as a consequence of global climate change and coastal biological oxygen depletions. On the other hand, anthropogenic emissions of CO and consequent accumulation in the sea surface result in a perturbation of the seawater carbonate system, including a decrease in pH, known as ocean acidification. While the effect of decreases in pH and dissolved oxygen (DO) concentration is better understood, their combined effects are still poorly resolved.

Chronology of trace elements and radionuclides using sediment cores in Golden Horn Estuary, Sea of Marmara.

Trace elements and radionuclides are substantial pollutants in marine environment since they are non-biodegradable and can be harmful even in minute concentrations. The Golden Horn estuary, where is an inlet of Bosphorus and two creeks, has been seriously polluted by untreated municipal and industrial dischargers for several decades. Since 1998, a large restoration and rehabilitation efforts have been undertaken in the estuary to mitigate the pollution.

Microplastic inventory in sediment profile: A case study of Golden Horn Estuary, Sea of Marmara.

Assessment of microplastics (MPs) in sediment cores is necessary to unveil global plastic pollution since most of the plastic litter might have been stored in sediment columns. In the current study, MPs inventory was determined in a 105 cm sediment core, collected in the Golden Horn Estuary, Sea of Marmara. Radiodating of sediment profile by using naturally occurring Pb and fission product Cs allowed us to couple the retrospective of global MP production to sediment MPs inventory.

Impacts of elevated pCO on Mediterranean mussel (Mytilus galloprovincialis): Metal bioaccumulation, physiological and cellular parameters.

Ocean acidification alters physiology, acid-base balance and metabolic activity in marine animals. Near future elevated pCO conditions could be expected to influence the bioaccumulation of metals, feeding rate and immune parameters in marine mussels. To better understand such impairments, a series of laboratory-controlled experiment was conducted by using a model marine mussel, Mytilus galloprovincialis.

Effects of microplastics and mercury on manila clam Ruditapes philippinarum: Feeding rate, immunomodulation, histopathology and oxidative stress.

Plastic pollution, which is one of the most important environmental problems at the present time, has been understood recently, and the effects of this pollution on ecosystem and biota are becoming a growing problem, especially in the aquatic ecosystems. Direct or indirect exposure to those particles leads to adverse effects on marine organisms. In the marine environment, plastic materials interact with other pollutants such as metals, thereby affecting the uptake levels of those pollutants in marine organisms.

Mercury and Po-210 in mollusc species in the island of Gökçeada in the north-eastern Aegean Sea: Bioaccumulation and risk assessment for human consumers.

Among the radioactive pollutants Po is the most substantial one in terms of seafood safety due to its efficient accumulation in marine animals and high irradiation of its alpha emission. Mercury is a highly toxic metal for both marine organisms and human beings. Biomagnification of MeHg (methylmercury) through marine food chains has made Hg concern of ecotoxicology and seafood safety.

Multi-pollutant Monitoring in a Rehabilitated Estuary: Elements and Radionuclides.

The Golden Horn Estuary, Istanbul, Turkey, had been exposed to untreated industrial discharges and municipal wastewater for over fifty years; however, during the last fifteen years pollution has been reduced due to an extensive rehabilitation campaign. Since sediment is the main accumulation matrix of marine ecosystems, surface sediment samples were collected from the estuary and analyzed for concentrations of some elements and radioactivity. The elements of predominant anthropogenic origin such as As, Cu, Pb, Sb, Sn and Zn and Cs were observed in the mid-estuary.

Effects of ocean acidification on Cd, Co, and Cs bioconcentration by the European oyster (Ostrea edulis): Biokinetics and tissue-to-subcellular partitioning.

The uptake and depuration kinetics of dissolved Cd, Co and Cs were determined experimentally in the European flat oyster Ostrea edulis (Linnaeus, 1758) under different pH conditions (i.e., 8.

Geochronology and sources of heavy metal pollution in sediments of Istanbul Strait (Bosporus) outlet area, SW Black Sea, Turkey.

Geochemical and sedimentological analyses and radionuclide (Pb and Cs) dating of three cores from the Bosporus outlet area of the Black Sea, north of Istanbul, were conducted to assess the sources and history of heavy metal pollution. The sedimentary succession in the shelf core KD12-01 consists mainly of clay (49-80%) and silt (15-41%). Radionuclide dating of the core indicates that it consists of old sediments that are uncontaminated with heavy metals.

Acidified seawater increases accumulation of cobalt but not cesium in manila clam Ruditapes philippinarum.

The pH of seawater around the world is expected to continue its decline in the near future in response to ocean acidification that is driven by heightened atmospheric CO emissions. Concomitantly, economically-important molluscs that live in coastal waters including estuaries and embayments, may be exposed to a wide assortment of contaminants, including trace metals and radionuclides. Seawater acidification may alter both the chemical speciation of select elements as well as the physiology of organisms, and may thus pose at risk to many shellfish species, including the manila clam Ruditapes philippinarum.

Trophic transfer of Cs in the Manila clam Ruditapes philippinarum.

Bioaccumulation of radiocaesium in many marine organisms occurs through complex trophic transfer mechanisms. The present study addresses the trophic transfer of Cs in the widely distributed marine bivalve, the Manila clam Ruditapes philippinarum, by experimentally determining the assimilation efficiency (AE) and the specific role of food quality or diet on the AE in this marine invertebrate. Pulse-chase feeding experiments were carried out on this clam using the phytoplankton species Tetraselmis chuii, Phaeodactylum tricornutum and Isochrysis galbana.

Biokinetics of radiocesium in shrimp (Palaemon adspersus): seawater and food exposures.

The bioaccumulation of (134)Cs was studied in the shrimp Palaemon adspersus (Rathke, 1837) using dissolved or food pathways. The uptake and loss kinetics (following seawater and food uptake) were followed for 27 and 38 days, respectively. The steady state concentration factor (CFss) value of (134)Cs in the whole body of the shrimp was found to be 15 ± 0.