Preliminary Assessment of Stress and Genotoxicity Biomarkers in Bivalve Molluscs from the Gulf of Annaba, Algeria

Investigating seasonal metal impact on Stramonita haemastoma gastropod along the Algerian East Coast: Understanding through various pollution indicators

The main objective of this study was to assess the impact of environmental pollution on the gastropod Stramonita haemastoma by examining various physiological and biochemical parameters. Trace metal elements (TME) were measured in the snail's foot. Over a one-year period from 2013 to 2014, the study investigated the variations in reduced glutathione, malondialdehyde, metallothionein, glutathione S-transferase, acetylcholinesterase and catalase activities in the foot of the gastropod at three different sites. The results showed spatiotemporal fluctuations in biomarkers, physiological parameters and TME. This integrative approach, being the first of its kind in the region using S. haemastoma as a model organism, represents a means of environmental assessment accessible to all countries allowing the monitoring and conservation of coastal marine environments on a national and international scale and which could be used in marine biomonitoring programs to indicate the impact of pollution and assess the quality of the Algerian coastal marine environment.

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 pCO₂-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^-1) and polluted-high (100 μg L^-1) concentrations in unacidified (pH 8.10) and acidified (pH 7.70/moderate OA and 7.30/extreme OA) seawater for 21 days. Following coexposure, metal bioaccumulation and responses of antioxidant defence-related biomarkers to OA and Cu coexposure were investigated. Results showed that metal bioaccumulation was positively correlated with waterborne metal concentrations but was not notably influenced by OA conditions. Both Cu and OA affected the antioxidant responses to environmental stress. Additionally, OA induced tissue-specific interactions with Cu on antioxidant defences, varying with exposure conditions. In unacidified seawater, antioxidant biomarkers were activated to defend against oxidative stress induced by Cu and prevented clams from lipid peroxidation (LPO or MDA), but failed to defend against DNA damage (8-OHdG). OA exacerbated Cu toxicity in antioxidant defences and increased LPO levels in tissues. Gills and viscera adopted adaptive antioxidant defence strategies to manage oxidative stress, with the former being more vulnerable to oxidative stress than the latter. MDA and 8-OHdG were sensitive to OA and Cu exposure, respectively, and were useful bioindicators for assessing oxidative stress. Integrated biomarker response (IBR) and PCA can reflect the integrative responses of antioxidant biomarkers to environmental stress and illuminate the contributions of specific biomarkers to antioxidant defence strategies. The findings provided insights for understanding antioxidant defences against metal toxicity in marine bivalves under OA scenarios, which is essential into managing wild populations.

Wild Garlic Allium triquetrum L. Alleviates Lead Acetate-Induced Testicular Injuries in Rats

The current study investigates the potential alleviating activity of bulbs (B) and leaves (L) of Allium triquetrum aqueous extract (ATE) on repro-toxicity induced by lead acetate (Pb) in male Wistar rats administrated orally for 3 consecutive weeks. Eighteen groups of rats were divided into the control, Pb (500 mg/kg body weight/day), positive controls of B and L (2 g, 3 g, 4 g, 6 g/kg body weight/day), in addition to four mixtures of each of Pb-B (Pb-B1, Pb-B2, Pb-B3, Pb-B4) and Pb-L (Pb-L1, Pb-L2, Pb-L3, Pb-L4). The two extracts were subjected to phytochemical screening and HPLC analysis. Sperm characteristics were evaluated by CASA system, as well as the serum testosterone, testicular and epididymal levels of glutathione (GSH), glutathione peroxidase (GPx), and malondialdehyde (MDA). The phytochemical screening proved that bulbs' and leaves' extracts were rich in various compounds and the HPLC showed that leaves contain more tannins. Results revealed a significant decrease in the testicular and in the epididymal weights, sperm concentration, motility, testosterone, velocity, vitality, round cells, GSH, and GPx levels in the Pb-intoxicated rats compared to the control, with the exception of MDA concentration that was significantly increased. However, the co-administration of garlic extracts (Pb-B and Pb-L) exhibited a significant increase in all mentioned markers, except for the MDA level which was reduced. Likewise, Pb caused histological injuries in the testicular seminiferous of rats, while the co-administration of wild garlic has reduced such effect, especially in the higher doses. Both extracts of Pb-B and Pb-L have attenuated Pb toxicity in a dose-dependent manner. In conclusion, aqueous extracts of A. triquetrum have the potential to reduce Pb testicular injuries by boosting sperm characteristics and ameliorating oxidative stress markers.

Growth and reproduction of Donax trunculus from the Gulf of Annaba (Northeast Algeria) in relation to environmental conditions

This study was aimed to evaluate the physiological reproductive end points (sex ratio, gametogenic cycle) and biological indices (condition index, length-weight relationship) in D. trunculus collected monthly over the year 2016, from two sites of the Gulf of Annaba (Northeast Algeria): El Battah (relatively unpolluted site) and Sidi Salem (polluted site). The results showed that gametogenesis takes place from December to August in both sites, with an autumnal resting phase. Also, the spawning occurred between March and August with two major spawning phases: April and August in El Battah vs May and August in Sidi Salem. The condition index showed a significant decrease in Sidi Salem site and positive correlation with gonad index. Moreover, the sites exert a significant effect on the allometric relationship and no significant effect on sex ratio. The observed reproductive events are discussed with the changes in the biological indices and the levels of pollution in the studied sites.

Effects of pollution on marine organisms

This review covers selected 2019 articles on the biological effects of pollutants, including human physical disturbances, on marine and estuarine plants, animals, ecosystems, and habitats. The review, based largely on journal articles, covers field, and laboratory measurement activities (bioaccumulation of contaminants, field assessment surveys, toxicity testing, and biomarkers) as well as pollution issues of current interest including endocrine disrupters, emerging contaminants, wastewater discharges, marine debris, dredging, and disposal. Special emphasis is placed on effects of oil spills and marine debris due largely to the 2010 Deepwater Horizon oil blowout in the Gulf of Mexico and proliferation of data on the assimilation and effects of marine debris microparticulates. Several topical areas reviewed in the past (e.g., mass mortalities ocean acidification) were dropped this year. The focus of this review is on effects, not on pollutant sources, chemistry, fate, or transport. There is considerable overlap across subject areas (e.g., some bioaccumulation data may be appeared in other topical categories such as effects of wastewater discharges, or biomarker studies appearing in oil toxicity literature). Therefore, we strongly urge readers to use keyword searching of the text and references to locate related but distributed information. Although nearly 400 papers are cited, these now represent a fraction of the literature on these subjects. Use this review mainly as a starting point. And please consult the original papers before citing them.