Native Fish Monitoring – Shannon and Penstock Lagoons
Recently, we carried out surveys of the native fish populations at Shannon and Penstock lagoons. There are three species of native galaxiid fish within each of these waters, the Shannon paragalaxias and Great Lake paragalaxias both listed as threatened, and the more widespread and abundant Spotted galaxias, often referred to as ‘mountain trout’.
During the suvey we found the Shannon paragalaxias and Spotted galaxias were abundant at both waters and there were good signs of strong recruitment of young fish. The Great Lake paragalaxias was also found at both waters, however this species was at much lower numbers, which is normally the case. This species is more abundant at the near-by yingina / Great Lake, where it is found in and around the rocky edges, especially during Spring when they spawn along the shoreline on the undersides of submerged rock.
A pleasing observation during the survey was the very clear water at Penstock Lagoon and the number of invertebrates in the shallows, despite low water temperatures. Furthermore, the turbidity levels at Shannon Lagoon continue to improve with visibility of around ½ to ¾ of a metre! It seems the native fish are holding their own at present.