Data collected includes the following: Densities of yellow eel, juvenile salmon and juvenile trout at 40-50 sites, fish (per m2) and lengths of individual fish. Data collected from the Burrishoole catchment rivers and lakes within Furnace Newport Co. Mayo. Data surveys have taken place annually since 1959. Data surveys have involved surveys of salmon and trout stocks taking place in the rivers and main lakes of the catchment. Electrofishing, with 3 fishing depletions, are used for salmonids in the streams and fine mesh beach seines are used in the lakes. Data has been collected to ascertain knowledge on the abundance of key target species in the Burrishoole catchment. Data originally collected by the Guinness Estate and more recently by the Marine Institute Newport facility team. Data is 100% complete for each year since 1959.