Lough Furnace

{{Short description|Lake in County Mayo, Ireland}}

{{Use dmy dates|date=November 2021}}

{{Use Irish English|date=November 2021}}

{{Infobox body of water

| name = Lough Furnace

| native_name ={{native name|ga|Loch na Foirnéise}}

| image = File:SeeIrland.jpg

| caption =

| pushpin_map = Ireland

| image_bathymetry =

| caption_bathymetry =

| location = County Mayo, Ireland

| coords = {{coord|53.916698|N|9.570908|W|region:IE_type:waterbody|display=inline,title}}

| lake_type = Saline Lagoon

| inflow = Lough Feeagh, Yellow River

| outflow = Burrishoole Channel, to Clew Bay

| catchment = Burrishoole

| basin_countries = Ireland

| date-flooded =

| length =

| width =

| area = {{convert|1.5|km2|abbr=on}}

| depth =

| max-depth = {{convert|20|m}}

| volume =

| residence_time =

| shore =

| elevation = {{convert|4|m|ft|abbr=on}}

| islands = Inishower, Illanroe, Saint's Island

| cities =

}}

Lough Furnace ({{Langx|ga|Loch na Foirnéise}}) is a tidally-influenced, meromictic, saline lagoon in County Mayo, Ireland, located south of Lough Feeagh.{{cite web|url=http://www.marine.ie/Home/site-area/infrastructure-facilities/newport-catchment-facilities/burrishoole-fishery-0|title=Burrishoole Fishery|publisher=}} It receives freshwater inflow from the upstream Lough Feeagh at the base of the Burrishoole Catchment and tidal input of saline water from Clew Bay, through the Burrishoole Estuary.

The lagoonal estuary is notable for the perennially anoxic deep water in the main inner basin.{{cite journal|last1=Kelly|first1=S.|last2=Eyto|first2=E. de|last3=Dillane|first3=M.|last4=Poole|first4=R.|last5=Brett|first5=G.|last6=White|first6=M.|title=Hydrographic maintenance of deep anoxia in a tidally influenced saline lagoon|url=http://www.publish.csiro.au/mf/MF17199|journal=Marine and Freshwater Research|language=en|doi=10.1071/MF17199|date=12 December 2017|volume=69|issue=3|page=432|url-access=subscription}} Tidal currents transport salty, dense oceanic water from Clew Bay into the inner basin and river inflows form a buoyant seaward surface layer. The large density contrast between these two water layers limits vertical mixing and the salty, dense bottom water becomes isolated and develops stagnant, anoxic conditions. Given the highly unusual physical environment, Furnace has served as a model system for important ecologically-motivated research including the population dynamics of euryhaline invertebrates,{{cite journal|last1=Parker|first1=M.|last2=West|first2=B.|title=The natural history of Neomysis integer (Leach) in Lough Furnace, Co. Mayo, a brackish lough in the west of Ireland|url=http://www.sciencedirect.com/science/article/abs/pii/0302352479900719|journal=Estuarine and Coastal Marine Science|language=en|doi=10.1016/0302-3524(79)90071-9|date=February 1979|volume=8|issue=2|pages=157–167|url-access=subscription}} a paleolimnological reconstruction of its evolution toward anoxic conditions, which appears to have occurred at ca. 3400 calendar years before present,{{cite journal|last1=Cassina|first1=F.|last2=Dalton|first2=C.|last3=Dillane|first3=M.|last4=Eyto|first4=E. de|last5=Poole|first5=R.|last6=Sparber|first6=K.|title=A multi-proxy palaeolimnological study to reconstruct the evolution of a coastal brackish lake (Lough Furnace, Ireland) during the late Holocene|url=http://www.sciencedirect.com/science/article/abs/pii/S0031018213001909|journal=Palaeogeography, Palaeoclimatology, Palaeoecology|language=en|doi=10.1016/j.palaeo.2013.04.016|date=August 2013|volume=383-384|pages=1–15|hdl=10793/957|hdl-access=free}} divergent evolution in fish ecotypes,{{cite journal|last1=Ravinet|first1=M.|last2=Hynes|first2=R.|last3=Poole|first3=R.|last4=Cross|first4=T.F.|last5=McGinnity|first5=P.|last6=Harrod|first6=C.|last7=Prodöhl|first7=P.A.|title=Where the Lake Meets the Sea: Strong Reproductive Isolation Is Associated with Adaptive Divergence between Lake Resident and Anadromous Three-Spined Sticklebacks|journal=PLOS ONE|language=en|doi=10.1371/journal.pone.0122825|date=14 April 2015|volume=10|issue=4|pages=e0122825|pmid=25874617|pmc=4397041|doi-access=free}} bio-physical interactions between benthic fish and internal waves{{cite journal|last1=Kelly|first1=S.|last2=Eyto|first2=E. de|last3=Poole|first3=R.|last4=White|first4=M.|title=Ecological consequences of internal seiches in a semi-enclosed, anoxic coastal basin|url=http://www.int-res.com/abstracts/meps/v603/p265-272/|journal=Marine Ecology Progress Series|language=en|doi=10.3354/meps12727|date=17 September 2018|volume=603|pages=265–272|s2cid=91758400 |url-access=subscription}} and dynamics of sub-surface chlorophyll maxima.{{cite journal|last1=Eyto|first1=E. de|last2=Kelly|first2=S.|last3=Ryder|first3=E.|last4=Dillane|first4=M.|last5=Archer|first5=L.|display-authors=etal|title=High frequency monitoring reveals fine scale spatial and temporal dynamics of the deep chlorophyll maximum of a stratified coastal lagoon|url=http://www.sciencedirect.com/science/article/abs/pii/S0272771418307236|journal=Estuarine, Coastal and Shelf Science|language=en|doi=10.1016/j.ecss.2018.12.010|date=5 March 2019|volume=218|pages=278–291|s2cid=134902498 |url-access=subscription}}

Lough Furnace is the lower part of the Burrishoole fishery. It contains salmon, grilse and sea trout.{{cite web|url=http://www.paddymcdonnell.ie/lough-furnace/|title=Lough Furnace|publisher=}}{{cite web|url=http://www.fishinginireland.info/salmon/northwest/burrishoole_fishery.htm|title=Fishing in Ireland. An angler's guide to the best fishing in Ireland.|publisher=}}