https://www.selleckchem.com/products/7-12-dimethylbenz-a-anthracene-dmba.html Mercury- Selenium concentrations were determined in 136 samples of Carcharhinus falciformis (Silky shark) sampled from the Chiapas coast, Gulf of Tehuantepec, Mexico during August 2014 - January 2015. Average Hg concentrations in neonates and juveniles (all values in μg g-1 w.w.) were found to be 0.115 and 0.129 respectively, below the maximum permissible limit of 1 μg g-1 set by the Mexican government. However, excess Se values (all values in μg g-1 d.w.) observed in neonates (5.366) and juveniles (2.815) prove to maintain antioxidant ability by inducing Hg excretion and reducing its toxicity. Calculated Biomagnification Factor (BMFTL) denoted high values for the prey C.hippurus, signifying absolute magnification of Hg and Se along the food chain. This study provides key toxicological evidences of Hg- Se interaction and their effects in marine systems and human health. Long-term effects of environmental factors on phytoplankton community in Deep Bay, Hong Kong, were investigated from 1994 to 2016. Phytoplankton community experienced three important shifts small flagellates and Chroomonas spp. dominated from 1994 to 2006. Heavy blooms of diatoms Skeletonema costatum and Thalassiosira spp. occurred and became the dominant species between 2007 and 2009. Phytoplankton community was dominated by small flagellates and Chroomonas spp. from 2010 to 2015, and their abundance was much higher than earlier periods. Abundance of Chroomonas spp. decreased sharply in 2016, and Thalassiosira spp. became the dominant species. Phytoplankton community changed from consisting mainly of small flagellates and Chroomonas spp. to more diatoms, changing from ~90% to ~45% for other species abundance and from less then 10% to ~55% for diatoms. Nitrite, 5-day biochemical oxygen demand, salinity, suspended solids and turbidity were more influential on phytoplankton variation (23.65% explained by all the variables). M