The Sitemap XML protocol is also extended to provide a way of listing multiple Sitemaps in a 'Sitemap index' file. The maximum Sitemap size of 50 MiB or 50,000 URLs means this is necessary for large sites. An example of Sitemap index referencing one separate sitemap follows.
Cultural or artificial eutrophication occurs when human activity introduces increased amounts of these nutrients, which speed up plant growth and eventually choke the lake of all of its animal life.n nature, eutrophication is a common phenomenon in freshwater ecosystems and is really a part of the normal aging process of many lakes and ponds. Some never experience it because of a lack of warmth and light, but many do.
Eutrophication is the artificial enrichment of an aquatic system by the addition of nutrients[?]. The effect is often unintentional and harmful, indirectly causing the death of aquatic plants and animals. It is primarily caused by the leaching of phosphate or nitrate containing fertilisers into lakes or rivers. Some algae and blue-green bacteria thrive on the excess ions and a population explosion known as algal bloom occurs. This growth is unsustainable, however.