POTENTIAL ERROR WITH IN-SITU SURVEYS OF SMALLMOUTH BASS, MICROPTERUS-DOLOMIEU LACEPEDE, AS DETERMINED BY RADIOTELEMETRY

In situ surveys using scuba are important tools in the management of s mallmouth bass (Micropterus dolomieu) in boreal, clear lakes of North America. Population estimates that are derived from such surveys may b e erroneous if the size composition of the fish observed by divers dif fers from that of the entire population. Forty-four adult smallmouth b ass of three size classes were radio-tagged and tracked during the sum mer of 1993 (mid June to early September) in Green Lake, Maine, USA, t o investigate possible site-related error from observations by divers being towed along the lake shore. Our results indicate that scuba dive rs may fail to count a significant portion of large smallmouth bass du ring late summer (mid July to early September), compared to small-or m edium-sized fish. The results suggest that scuba surveys should be con ducted during early summer (mid June to mid July) to derive more accur ate population estimates. (C) 1997 Elsevier Science B.V.