User:MichelleEngel8/Lough Feeagh

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Lough Feeagh (Irish: Loch Fíoch) is a freshwater lake in County Mayo, Ireland. It is the largest of the lakes in the Burrishoole catchment, which consists of seven lakes and interconnecting rivers and streams. Lough Feeagh is one of the lakes observed and studied by the Global Lake Ecological Observatory Network (GLEON).

Lough Feeagh drains into Lough Furnace, which then drains through the short Burrishoole Channel into Clew Bay.

Limnology
Lough Feeagh is located at (53°50′N; 9°35′W) in western Ireland, in a valley of the Nephin Beg mountain range. The maximum depth is 45 m and the surface area is 3.9km2. Lough Feeagh is a temperate monomictic lake. Lough Feeagh is the largest freshwater lake in the Burrishoole catchment at 410 ha, which drains into Clew Bay through the Burrishoole Channel. Lough Feeagh formed from glacial movements as the glacier retreated to the Atlantic around 15,000 BC and is a freshwater lake. The lake shore and surrounding mountains can be like a tundra and feature few trees. The lake is important to the Atlantic salmon, European eel, and sea trout due to its connection with Lough Furnace, a tidal lagoon connected to the Atlantic coast with brackish water.

Lough Feeagh is an oligotrophic lake. These types of lakes are more common in colder areas such as Ireland due to the way colder temperatures affect how the water column mixes and stratifies and oligotrophic lakes usually are mixed less. Lough Feeagh is also considered a deep humic lake, meaning that the water is more brown than clear from the presence of Dissolved Organic Matter such as peat, and the pH of the water is usually more acidic. Humic Lakes are typical to the western Ireland. The water of Lough Feeagh drains into Lough Furnace through two streams: Salmon Leap and Mill Race. Salmon Leap is a naturally occurring channel, whereas 20- meter Mill Race was manmade. Both of these streams are steep and can usually only be passed by salmon and other fishes in one direction. The fish can migrate into Lough Furnace, but cannot swim back into Lough Feeagh. Some species of fish, such as lake trout, require well oxygenated, cold water that oligotrophic lakes provide. Lough Feeagh is an important lake in studying these species.

History
Lough Feeagh has had a human presence since the Iron Ages and is a part of local folklore. Lough Feeagh and Lough Furnace are considered to be the best for salmon fishing in Ireland. Mayo County now only allows fishing in Lough Furnace during a certain season, and no salmon fishing is allowed in Lough Feeagh. There is a history of spinning and weaving along the shores until the 1950s, known as the Buckagh Mountain weavers. Lough Feeagh has been monitored by the Marine Institute through the Automatic Water Quality Monitoring Station (AWQMS) since 1996, and the data they collect goes towards the Global Lake Ecological Observatory Network (GLEON).

Research
Lough Feeagh participates in a worldwide, 25 year study on the effect of climate change on lake temperature. As part of this study, they observed a 0.34˚C increase in temperature each decade. Lough Feeagh specifically warmed at a rate of 0.35° C per decade in a 25 year span from 1985-2009. The National Maritime Museum of Ireland also reports that Lough Feeagh is watched internationally to observe how diadromous fish will react to the warming temperatures. It is important to monitor the changes to lake ecosystem because of their freshwater supply for drinking and crop irrigation, the fish supply for food, and the energy created for the use of manufacturing and production. They further observed that lakes in the north have shorter seasons of ice cover and greater light intensity during the day, which fundamentally affects how the lakes mix their water column. Lough Feeagh is essential to these limnological studies because of the consistency and length of time monitoring the water quality, thus allowing for global comparisons and connecting to greater trends of climate change viewed around the world.

In 1997, a study occurred in Lough Feeagh and Lough Furnace looking at the effect of farmed salmon genetics on native salmon populations. The study tries to understand how closed off breeding programs that raise salmon from Norwegian Mowi stock within cages can lose a small number of salmon into the open lakes and how that loss can affect the local populations. Using traps in the Srahrevagh River feeding into Lough Furnace, samples from electrofishing, and controls from a hatchery, they found that escaped farmed salmon can survive into the smolt stage. If the foreign fish are introduced to the natural ecosystem, they can take over the nutrients going to the local fish and choke out the native population. The farmed fish are also genetically isolated for generations since the early 1980s and in culture since the 1960s, this isolation in the genes can cause complications once mixed with current populations.

Lough Feeagh was also a part of another research study which examined patterns of respiration and gross primary production. This study in 2013 found that at the daily level oligotrophic and dystrophic lakes have a stronger relation between primary production and respiration than eutrophic lakes. In particular to Lough Feeagh, it has a low total amount of phosphorus, and yet the level of net respiration is not as high as in other lakes that follow the pattern. It is suggested that this lake diverges from the pattern because of a large amount of water entering the system from several rivers and constantly moving the water column. Overall, the study found that lakes with high total phosphorus (TP) have low levels of respiration, and lakes with low TP have high levels of respiration.

Another research study from 2000 looked at Lough Feeagh and Lough Leane to determine whether the North Atlantic Oscillation (NAO) weather event was affecting variation in temperature. The results of this study found that Lough Feeagh had warmer lake surface temperatures in winters that had a positive NAO event, and thus the lake experienced an increase in algal blooms from that winter. The weather event also affects the temperature of the soil on land, which may lead to denitrification of the soil, not delivering nitrogen, a key nutrient, to the lake system.