Boaters fear it. Not because it attacks. Because it jumps. When startled by boat engines or loud noises the silver carp launches itself out of the water like a silver missile. At speeds exceeding 50 kilometres per hour these fish can reach heights of three metres. They break bones damage equipment and terrify anyone on the water. Introduced to New Zealand in the 1970s for algae control the silver carp has become a nuisance species in several North Island waterways. Native to eastern Asia this large cyprinid reaches up to 1 metre in length and can weigh over 20 kilograms. Its silvery scales and distinctive upward-facing mouth make it unmistakable. The fish inhabits lakes and slow-flowing rivers where plankton concentrations are high. It prefers warm nutrient-rich waters often found in agricultural catchments where fertiliser runoff fuels algal blooms. Unlike native filter feeders the silver carp consumes vast quantities of phytoplankton stripping the base of the food web. Spawning occurs in flowing water during spring and summer. Eggs are released into the current where they drift downstream hatching in warm temperatures. In New Zealand most silver carp are sterile triploids introduced specifically for algae control without establishing breeding populations. However fertile individuals have been detected raising concerns about uncontrolled reproduction. Diet consists almost entirely of phytoplankton and zooplankton. The fish filters water through specialised gill rakers consuming microscopic organisms at extraordinary rates. This feeding behaviour competes directly with native fish larvae and juvenile stages that rely on the same food sources. Water clarity increases but biodiversity decreases as the plankton base collapses. Classified as Introduced the silver carp faces strict controls in New Zealand. Sterile triploid individuals are occasionally used for targeted algae management under permit but wild populations are actively managed through removal programmes. The threat to native ecosystems is significant. Lakes stripped of plankton lose their ability to support diverse fish communities. Conservation efforts focus on preventing further introductions and removing established populations before they spread.