Dead fish a ‘natural cycle’
Hundreds of tiny fish have been washing up on Lake Taupo¯ beaches?
James Barnett from the Department of Conservation’s Taupo¯ Trout Fishery management says the dead fish are no cause for alarm. ‘‘This is a natural occurrence. ‘‘It’s a cyclical event. The species involved is the common bully, which spawns in the shallows during the summer.’’
The deaths happen every summer, but normally the deaths are spread out over a period of time, Barnett said.
‘‘Increased water temperatures, combined with the rigor of defending their eggs, take a huge toll on bullies, resulting in large-scale deaths.’’
The bullies are an important source of food for trout, helping sustain smelt during their larval stage and trout as adults, he said.
However, the deaths are unlikely to affect trout populations. ‘‘It’s a natural food cycle: it shouldn’t have any significant impact at all,’’ Barnett said.
‘‘There will still be other generations of bully that haven’t met sexual maturity yet, which will come through.’’
The common bully can be found throughout New Zealand.
‘‘They usually have a sea-going larval phase. However, lake-based populations have become established in many areas, including Lake Taupo¯ .’’
The little fish washing up on Lake Taupo¯ beaches will have died from warm summer water temperatures.