salmon populations. Lough Leane is approximately in size and is by far the largest of the three lakes. It is also the largest body of fresh water in the region. It is also the lake richest in nutrients. It has become eutrophic as a result of phosphates from agricultural and domestic pollution entering Lough Leane Reedbed, an important habitat on the edge of Lough Leane. This nutrient enrichment has caused several algal blooms in recent years. The blooms have not yet had a severe effect on the lake's ecosystem. To prevent further pollution causing a permanent change in the lake's ecosystem, a review of land use in the catchment area is being carried out. Water quality in the lake appears to have improved since phosphates were removed from sewage in 1985. As of August 2007, several large hotels and businesses have stated their intention to stop using phosphate detergents, in an effort to preserve the quality of the lake water. Muckross Lake is the deepest of the three lakes. It has a maximum depth of , close to where the steeply sloping side of Torc Mountain enters the lake. The lake lies on the geological boundary between the sandstone mountains to the south and west and the limestone to the north. Lough Leane and Muckross Lake lie across the geological boundary. The presence of limestone causes both of the lakes to be slightly richer in nutrients than the Upper Lake. There are many caves in the limestone at lake level, created by wave action combined with the dissolution effect of the lakes' acidic water on the exposed rock. These caves are largest on the northern shore of Muckross Lake. From the Meeting of the Waters a narrow channel called the Long Range leads to the Upper Lake, the smallest of the three lakes. This lake is located in rugged mountain scenery in the upper Killarney/Black Valley area. The fast run-off in its catchment area can cause the level of the lake to rise by up to a meter in a few hours during heavy rain. Muckross Lake and the Upper Lake are high quality oligotrophic systems, with water that is slightly acidic and low in nutrients. This is caused by run-off from the upland sandstones and blanket bogs in their catchment areas. They have diverse aquatic vegetation, including quillwort (Isoetes lacustris), shoreweed (Littorella uniflora), and water lobelia (Lobelia dortmanna). All