Eels mature in UK and European rivers before migrating
Two thousand elvers are to be released at a wildlife park in a bid to address the decline of the species in the UK and the rest of Europe.
The Environment Agency and the RSPB are boosting the eel stocks at the Minsmere reserve in Suffolk where the habitat is described as ideal for eel development.
"It has shallow lakes with reed-beds, connection to rivers and no commercial fishing," an agency spokeswoman said.
"Numbers of eels reaching maturity and migrating to spawn will increase too."
The only known spawning ground for eels is the Sargasso Sea, south of Bermuda.
The spokeswoman said: "Eel larvae follow the Gulf Stream and North Atlantic Drift to return to Europe metamorphosing into glass eels when they reach the continental shelf.
"Glass eels are attracted to freshwater and enter UK rivers in the spring, historically in great numbers.
"After an average of six years for males and nine years for females, eels begin to mature, stop feeding and become silver in colouration.
"Silver eels swim downstream towards the sea to begin the long migration of 5500km back to the Sargasso Sea, where they will spawn and die."
Numbers have dropped dramatically in the past few years and are thought to be about 5% of the numbers in the 1980s.
The Environment Agency has prepared an Eel Management Plan for East Anglia to assess the status of eel stocks and actions needed to improve survival and distribution of all life stages.
The objective is to increase the numbers of adult silver eels able to migrate to the Sargasso Sea.