Barry Docks by Friar's point. It had been a port in Medieval times. The island was about long and wide, with a height of above mean sea level. The mainland slopes up to the north, so the sound was well sheltered from the wind. No rivers or streams ran into the sound. The Bristol Channel is known for the range of its tides. During normal spring tides there is a range in water level of , and during normal neap tides a range of but tides can peak at around in which case sea water flows into the dock over the top
Issues relating to biofuels ecosystems including rainforest in South America. In forest ecosystems, these effects themselves will undermine the climate benefits of alternative fuels, in addition to representing a major threat to global biodiversity. Although biofuels are generally considered to improve net carbon output, biodiesel and other fuels do produce local air pollution, including nitrogen oxides, the principal cause of smog. Issues relating to biofuels There are various social, economic, environmental and technical issues with biofuel production and use, which have been discussed in the popular media and scientific journals. These include: the effect of moderating oil prices, the "food vs fuel" debate, poverty