Multimedia distribution of polycyclic aromatic hydrocarbons in an intensive aquaculture area in the East China Sea: Focusing on bioaccumulation and health risks in mollusks.

Mollusks, beyond their critical significance in aquaculture, have long been recognized as sentinel species for monitoring chemical contaminants in aquatic ecosystems. This study presents a comprehensive assessment of polycyclic aromatic hydrocarbons (PAHs) in an intensive coastal aquaculture area, encompassing their multimedia distribution, tissue-specific accumulation, bioaccumulation dynamics, partitioning behavior, and associated health risks. Among the 16 analyzed PAHs, 15 were detected in inshore seawater, while all 16 were quantified in intertidal sediment and mollusks.

The incorporation of strontium and barium into the otoliths of the flounder Paralichthys olivaceus at early life stages demonstrates resilience to ocean acidification.

Ocean acidification could modify the bioavailability and chemical properties of trace elements in seawater, which could affect their incorporation into the calcareous structures of marine organisms. Fish otoliths, biomineralized ear stones made by aragonite, are suspended within the endolymph fluid of teleosts, indicating that the elemental incorporation of otoliths might also be susceptible to ocean acidification. In this study, we evaluated the combined effects of CO-induced ocean acidification (pH 8.

Interactive impacts of CO-induced seawater acidification and cadmium exposure on antioxidant defenses of juvenile tongue sole Cynoglossus semilaevis.

Antioxidant responses of juvenile sole exposed to seawater acidification (SA) and Cd were investigated. SA increased lipid peroxidation (LPO) in the fish, independent of Cd concentrations. Cd at medium and high levels inflated LPO under no or moderate SA conditions.

Ocean acidification induces tissue-specific interactions with copper toxicity on antioxidant defences in viscera and gills of Asiatic hard clam Meretrix petechialis (Lamarck, 1818).

Toxicity of contaminants in organisms under ocean acidification (OA) has attracted increasing attention in ecotoxicological studies. This study investigated how pCO-driven OA affected waterborne copper (Cu) toxicity in antioxidant defences in viscera and gills of Asiatic hard clam Meretrix petechialis (Lamarck, 1818). Clams were continuously exposed to Cu at ambient relevant (0/no metal exposure, 10 and 50 μg L) and polluted-high (100 μg L) concentrations in unacidified (pH 8.

pCO-driven seawater acidification affects aqueous-phase copper toxicity in juvenile flounder Paralichthys olivaceus: Metal accumulation, antioxidant defenses and detoxification in livers.

Ocean acidification potentially influences the biotoxicity of metals and the antioxidant defense systems of marine organisms. This study investigated how pCO-driven seawater acidification (SA) affected aqueous-phase copper (Cu) toxicity in the juvenile flounder Paralichthys olivaceus from the perspective of hepatic oxidative stress and damage to better understand the mechanisms underlying the biological effects produced by the two stressors. Fish were exposed to aqueous-phase Cu at relevant ambient and polluted concentrations (0, 5, 10, 50, 100 and 200 μg L) at different pH levels (no SA: pH 8.

Microplastic pollution in the environment and organisms of Xiangshan Bay, East China Sea: An area of intensive mariculture.

Microplastic (MP) pollution in oceans is an emerging environmental problem that poses ecological risks for marine ecosystems. Based on the abundance, distribution, and characteristics of microplastics (MPs) in surface water, sediment, and organisms, MP sources, pollution, trophic transfer, and ecological risk in Xiangshan Bay, an area of intensive mariculture in East China Sea, were assessed in this study. MPs were prevalent in the environment and organisms, with overall abundances at a low-medium level compared with the levels in the coastal areas.

Toxicological effects of cadmium on the immune response and biomineralization of larval flounder Paralichthys olivaceus under seawater acidification.

Seawater acidification can cause threats to both calcifying and uncalcifying marine organisms, affecting their acid-base regulatory functions, immune system and biomineralization. Marine pollutants, such as cadmium (Cd) that is globally distributed in coastal ecosystems, do not affect organisms alone but commonly as combined stressors. To investigate the toxicological effects of Cd on the immune and biomineralization of marine fishes under seawater acidification, flounder Paralichthys olivaceus was exposed to seawater acidification (control (pH 8.

Assessment of plastic pollution in the Bohai Sea: Abundance, distribution, morphological characteristics and chemical components.

Plastics are globally distributed in oceans and can pose a threat to the environment and organisms. In this study, plastic pollution in surface water and sediments of the Bohai Sea was assessed based on plastic abundance, distribution and characteristics (shape, polymer, size and color). Water and sediment samples were collected across the sea using a plankton net (330 μm) and a grab sampler, respectively.

Tissue-Specific Accumulation and Antioxidant Defenses in Flounder (Paralichthys olivaceus) Juveniles Experimentally Exposed to Methylmercury.

Methylmercury (MeHg) is the most toxic form of mercury and can accumulate in the cells of marine organisms, such as fish, causing adverse effects on various physiological functions. This study examined MeHg accumulation and its toxicological role in antioxidant defenses in tissues, including the liver, gills, and muscle of flounder (Paralichthys olivaceus) juveniles. After 30 d of MeHg exposure (0, 0.

Effects of seawater acidification and cadmium on the antioxidant defense of flounder Paralichthys olivaceus larvae.

Increasing atmospheric carbon dioxide has led to a decrease in the pH of the ocean, which influences the speciation of heavy metals and consequently affects metal toxicity in marine organisms. To investigate the effects of seawater acidification and metals on the antioxidant defenses of marine fishes, the flounder Paralichthys olivaceus, was continuously exposed to cadmium (Cd; control, 0.01 and 0.

Biomagnification of methylmercury in a marine food web in Laizhou Bay (North China) and associated potential risks to public health.

The concentrations of total mercury (THg) and methylmercury (MeHg) were assessed in water, sediment and biota (54 species) samples from the coast of Laizhou Bay, to evaluate MeHg biomagnification in Laizhou Bay food web. The trophic web structure was determined with stable isotope ratios. The MeHg concentrations were highly variable among species ranged from 4.

Antioxidant defenses and immune responses of flounder Paralichthys olivaceus larvae under methylmercury exposure.

Methylmercury (MeHg) is a highly toxic contaminant in coastal environments and poses threats to marine fish in early life stages (ELSs). However, MeHg toxicity to fish embryos and larvae is not well investigated. This study investigated the antioxidant defenses and immune responses of flounder Paralichthys olivaceus larvae exposed to waterborne MeHg (0, 0.

Interactive effects of strontium and barium water concentration on otolith incorporation in juvenile flounder Paralichthys olivaceus.

Although the relationship between the incorporation of an element into otoliths and the concentration of the element in water has been extensively investigated in many fish species, the interactive effects of multiple elements in water on the otolith incorporation of an element are not adequately explored or well understood. In this study, 16 treatments in triplicate using strontium (Sr; 1, 2, 3 and 4 times the ambient baseline, 6.5 mg l-1) and barium (Ba; 1, 2, 4 and 6 times the ambient baseline, 40 μg l-1) as categorical variables in an orthogonal design were established to evaluate the relative or interactive effects of water elements on otolith elemental incorporation in juvenile flounder Paralichthys olivaceus (from 15 to 116 days post hatching).

Toxicity Test Assay of Waterborne Methylmercury on the Japanese Flounder (Paralichthys olivaceus) at Embryonic-Larval Stages.

Methylmercury (MeHg) is a widespread pollutant in aquatic ecosystems, but its toxicity to the early life stages of marine fish has not been adequately investigated. This study used acute toxicity tests on embryonic-larval stages of a marine flounder Paralichthys olivaceus to determine the LC values for embryos and larvae and evaluate the responses of several biological endpoints to subacute MeHg exposure. Under exposures (0-15 μg L) below LC values ( < 15.

Bioaccumulation of heavy metals and health risk assessment in three benthic bivalves along the coast of Laizhou Bay, China.

This study investigated the tissue- and species-specific bioaccumulation of heavy metals (Cr, Cu, Hg, Zn, As, Cd, and Pb) in three benthic bivalves (the ark shell, Scapharca subcrenata; the surf clam, Mactra veneriformis; and the Manila clam, Ruditapes philippinarum) collected from the coast of Laizhou Bay in the Bohai Sea. The results demonstrated that the visceral masses of the bivalves tended to accumulate heavy metals more efficiently than their muscles. The capacities of the bivalves to bioaccumulate metals followed a similar order: Cd>Hg>Zn=As>Cu>Cr=Pb.

Morphological and histological changes in digestive tract development during starvation in the miiuy croaker.

A histological method was used to describe the ontogenetic development of the digestive tract of laboratory-reared miiuy croaker (Miichthys miiuy) and to evaluate the effects of short-term food deprivation on the morphology and histology of the digestive tract. Larvae and juveniles were maintained at 24 °C in a thermostatically controlled system. Three starvation experiments were conducted during different developmental stages: 1-7 days after hatching (dah; prior to benthic swimming); 26-35 dah (during settling); and 42-53 dah (after benthic swimming).

Tissue-specific accumulation of cadmium and its effects on antioxidative responses in Japanese flounder juveniles.

This study investigated the accumulation of cadmium (0-8 mg Cd L⁻¹) and its toxicological effects on oxidative stress biomarkers in different tissues of Japanese flounder juveniles. Following Cd exposure for 28 d, accumulation of Cd in fish was dose-dependent and tissue-specific, with the greatest accumulation in the liver, followed by the kidney, gill, and muscle. Although the gill and liver mounted active antioxidant responses at ≥ 4 mg L⁻¹ Cd including a decrease in glutathione level and GST and GPx activities, the antioxidant response failed to prevent lipid peroxidation induction in these organs.

Toxicity testing of waterborne mercury with red sea bream (Pagrus major) embryos and larvae.

Acute toxicity tests revealed that, in red sea bream (Pagrus major) embryos, 24 and 48 h LC(50) values of waterborne HgCl(2) were 67.3 and 39.1 μg Hg(2+) L(-1).

Short-term mercury exposure affecting the development and antioxidant biomarkers of Japanese flounder embryos and larvae.

This study investigated the acute and sub-lethal toxicities of waterborne mercuric chloride to Japanese flounder (Paralichthys olivaceus) embryos and larvae. Acute toxicity tests indicated that the 48-h LC(50) values of mercury to the embryos and larvae were 48.1 (32.

Toxicity of short-term copper exposure to early life stages of red sea bream, Pagrus major.

Acute (0, 0.1, 0.2, 0.

Antioxidative responses and bioaccumulation in Japanese flounder larvae and juveniles under chronic mercury exposure.

This study investigated the sub-lethal effects of waterborne mercury on growth, bioaccumulation and antioxidative responses of larvae and juveniles of Japanese flounder (Paralichthys olivaceus). Fish were exposed to 0-10 microg Hg(2)(+)L(-1) solutions from embryonic to the juvenile stages for 80 days. Antioxidative responses to mercury exposure were studied in metamorphosing larvae (18 days post hatching, dph), settling larvae (33 dph) and juveniles (78 dph).

Accumulation and oxidative stress biomarkers in Japanese flounder larvae and juveniles under chronic cadmium exposure.

This study investigated how Cd exposure affected oxidative biomarkers in Japanese flounder, Paralichthys olivaceus, at early life stages (ELS). Fish were exposed to waterborne Cd (0-48microg L(-1)) from embryonic to juvenile stages for 80days. Growth, Cd accumulation, activities of superoxide dismutase (SOD, EC 1.

Cadmium toxicity to embryonic-larval development and survival in red sea bream Pagrus major.

At 18 degrees C and 33 psu, 24 and 48 h LC(50) values of cadmium (Cd) for red sea bream Pagrus major embryos were 9.8 and 6.6 mgl(-1), respectively, while 24, 48, 72, and 96 h LC(50) values for larvae were 18.

Toxic effects of zinc on the development, growth, and survival of red sea bream Pagrus major embryos and larvae.

This study investigated the zinc toxicity to red sea bream Pagrus major embryos and larvae at 18 +/- 1 degrees C (33 +/- 1 per thousand in salinity) under laboratory conditions. The acute toxicity tests indicated that zinc 48-h LC50 to embryos and 96-h LC50 to larvae were 4.3 (3.