Declining stocks

• Concern over the status of the longfin eel population has become increasingly widespread over recent years. Clearly, the number of longfins has fallen dramatically over the last half century. It is a precarious life being a longfin eel, even without pressures from human activities.

  In the 1930s, European settlers declared eels ‘public vermin’ and embarked on an all-out extermination campaign – killing hundreds of thousands of eels. Thankfully, those days are long behind us.

  Ironically, it was the advent of commercial eel fishing in the 1960s that put an end to extermination campaigns. The eel harvesting industry continues to this day, having peaked at over 2,000 tonnes in 1972.

  The other human impact on eel populations is the damming of rivers and streams. Hydro-electric dams impact on eels in two ways_ by stopping young eels swimming upstream and by stopping adults in their journey downstream to the ocean to breed. Longfin eels are particularly affected by hydroelectric dams (and other barriers) because they tend to live higher up in catchments.