RE: ‘Losing control of our environment? (The Weekend Sun, January 20).K. Molloy insists that black swans and Canada geese are the primary cause of pollution in Tauranga Harbour. These birds simply recycle nutrients that are already there. As stated by the BOPRC, nutrients and sediment killing the harbour flow in from elsewhere in rivers polluted by intensive farming, from septic tanks and stormwater drains, and due to human interference with the landscape. K Molloy should visit the harbour around Turret Rd Bridge and Welcome Bay where no swans or geese are resident in spring and summer, yet sea lettuce is abundant, huge areas are anoxic due to sedimentation, and the historic cockle and pipi beds have disappeared. The complaint is reminiscent of, and is just as misinformed, as statements by fisherfolk who kill seals because seals eat fish. It is also worth noting here the swans and geese we have today may be introduced - some swans have self-introduced and they are strictly native - but NZ has extinct versions of both. There may well have been thousands of these birds on Tauranga Harbour before human arrival.

I McLean, Tauranga City.