Pond Life

Forest and Bird, Issue 291, 1 February 1999, Page 7

Pond Life

PhD, marine biologist.

Roger Grace,

We endorse Clint McCullough’s view on mosquitofish (Forest ¢& Bird, November 1998. "Damnbusia’ are unnecessary in ponds. We have a bush block near Warkworth, and three summers ago built two small dams to enhance its wildlife value. The dams were constructed in swampy ground in a bush valley early in March. Within two weeks, as they were slowly filling, the surface of both ponds were black with mosquito wrigglers. It was tempting to add mosquitofish but we wanted to establish a natural pond ecology, so did nothing. There was no human habitation within 500 metres so we figured the ‘mozzies’ would not be a problem to anyone. Within a few weeks backswimmers flew in, and diving beetles appeared. Although they were overwhelmed by the number of mosquito larvae that season, the following season was very different. Early next summer, mosquito larvae again appeared. Diving beetles and their larvae, and large numbers of backswimmers, quickly gobbled up all the mosquito wrigglers in one week! That was two years ago and we haven’t seen a mosquito wriggler in either pond since. The ponds have settled down and now contain lots of native insects, snails, a few koura and several species of pond weed. We have trouble with mosquitos at our residence in suburban Warkworth, but not at our bush block. It was just a matter of being patient for the first year then, once the natural pond ecology had established, ‘mozzies’ were not a problem.

PS. Since first writing, frogs and tadpoles have arrived