Nine-volt battery batteries were formerly made in this size. They had higher capacity than the then-standard carbon-zinc types, a nominal voltage of 8.4 volts, and very stable voltage. Once used in photographic and measuring instruments or long-life applications, they are no longer manufactured as mercury is highly toxic and accumulates in the ecosystem, posing a risk to humans and wildlife. Most battery voltage testers and chargers that can also test nine-volt need another snap clip to hold the battery, while cylindrical batteries often share a holder that may be adjustable in size. Because of the proximity of the positive and negative terminals
The Broads practices and sewage disposal in the 1950s and 1960s released high levels of phosphorus and nitrogen into the Broads, causing eutrophication. Algal blooms can be toxic, posing a health risk to humans and wildlife. Mass decay of plant matter removes oxygen, damaging fish stocks, preventing recreational fishing. The loss of larger plants and reed fringes in eutrophic waters increases erosion of banks and the buildup of sediment on lake floors. This impedes navigation and requires costly dredging to remove. The beauty of the area is damaged by eutrophication, which is detrimental to the tourism industry. The Broads authority and Environment