Effects of motor boats on submerged aquatic macrophytes
Published source details
Asplund T.R. & Cook C.M. (1997) Effects of motor boats on submerged aquatic macrophytes. Lake and Reservoir Management, 13, 1-12.
Published source details Asplund T.R. & Cook C.M. (1997) Effects of motor boats on submerged aquatic macrophytes. Lake and Reservoir Management, 13, 1-12.
Action: Physically exclude vehicles
A replicated, paired, controlled study in 1995 in a lake in Wisconsin, USA (Asplund & Cook 1997) reported that fencing to exclude motorboats typically increased the abundance and height of submerged macrophytes after 10 weeks. Macrophytes more abundant in fenced than open plots in eight of eight comparisons: four of four comparisons for above-ground biomass (fenced: 104–2,021 g/m2; open: 34–654 g/m2) and four of four comparisons for cover (fenced: 66–99%; open: 42–73%). Macrophytes were taller in fenced plots in three of four comparisons (for which fenced: 65–94 cm; open: 41–50 cm; other comparison no significant difference). In five of six comparisons, there was no significant difference in abundance or height between different fence types (solid or mesh; see original paper for data). Methods: In mid-June 1995, sixteen 6 x 6 m plots were established across two sites in Lake Ripley with heavy boat traffic. Eight plots (four plots/site) were fenced to exclude boats: half with solid clear plastic sheeting, and half with orange plastic barricade fencing. Fences extended 75 cm above the water surface and suspended 50 cm above the lake bed. The other eight plots were not fenced. Submerged macrophytes were surveyed by a snorkeller in late August 1995. Biomass included shoots only (roots and runners removed) and was dried before weighing.