Portskewett The village lost its railway station (on the Newport to Gloucester line) when it was closed under the Beeching Axe in 1964. Black Rock, on the Severn estuary immediately south east of the village, has been an important crossing point of the River Severn for many centuries. Numerous coins found in the mud show that it was in constant use throughout the Roman period, on the route between Aquae Sulis (Bath) and Venta Silurum (Caerwent). By the 18th century, a regular ferry service crossed the Severn estuary from Black Rock to New Passage on the Bristol side, carrying passengers, cattle
Aphanizomenon flos-aquae Aphanizomenon flos-aquae Aphanizomenon flos-aquae is a brackish and freshwater species of cyanobacteria found around the world, including the Baltic Sea and the Great Lakes. "Aphanizomenon flos-aquae" can form dense surface aggregations in freshwater (known as "cyanobacterial blooms"). These blooms occur in areas of high nutrient loading, historical or current. "Aphanizomenon flos-aquae" has both toxic and nontoxic forms. Most sources worldwide are toxic, containing both hepatic and neuroendotoxins. Most cyanobacteria (including "Aphanizomenon") produce BMAA, a neurotoxin amino acid implicated in ALS/Parkinsonism. Toxicity of "A. flos-aquae" has been reported in Canada, Germany and China. "Aphanizomenon flos-aquae" is known to produce endotoxins, the