The Foyle is famous for its salmon, a species once so abundant the servants of ‘big houses’ around Derry were served it as their daily staple.
But how many have heard of the European Smelt, a fish that is a relatively recent arrival to the famous Derry river system?
According to a new report by the Loughs Agency the species - which is fried and eaten in northern Germany and the Baltic States where it is also found - was first recorded in Derry in 1973 but is now an important part of the eco-system.
Up until their detection at the Coolkeeragh Power Station intake screens 45 years ago Smelt had only ever been reported before in Ireland in the River Shannon.
But now they are here in healthy numbers. And in a new conservation report on the species that surveyed their presence in the Foyle between 2012 and 2017 the Loughs Agency has concluded that they need to continue to be protected.
“European smelt are an important part of the native fisheries biodiversity of the Foyle area and indeed the island of Ireland,” the report states.
“At certain times and to certain audiences it can be an abstract concept that a species with no commercial or recreational value should be afforded conservation and protection efforts.
“Yet over recent years the concept of ecosystem services and quantifying the economic value of the environment can and is being calculated and analysed.
“Without too much effort direct links can be made between European smelt and more traditional economically significant species such as Sea trout and Atlantic salmon. European smelt play an important role in the ecosystem of Lough Foyle and the rivers which discharge into it.
“European smelt are an important prey item for numerous fish species of commercial and recreational interest that inhabit Lough Foyle utilising the productive waters as spawning, nursery and feeding territories for some or all of their lives,” the report adds.