Combining pond margin sampling and SCUBA-diving effectively assesses biodiversity from shallow to deep zones

For each selected pond, four quadrats of 4 m2 and spaced at least 5 m apart were selected at 8 different water depths (32 quadrats per pond, 64 quadrats in total). These depths were: 0.25 m, 0.50 m, 0.75 m, 1 m, 1.5 m, 2 m, 2.5 m and 3 m, nearly reaching the maximum depth of both ponds. Quadrats were selected to be representative of all microhabitats present (e.g. emergent vegetation, submerged vegetation, open water, etc.). For water deeper than 1 m, a line and dropper was used to determine water depth. Each quadrat from a depth of 0.25 m to 1 m was marked using a implanted pole, and each quadrat from a depth of 1.5 to 3 m was marked using floating buoys to ensure a constant depth was maintained while sampling. Macroinvertebrates were sampled within each quadrat for a total of 5 min, using a standard pond net (30 cm X 30 cm, 1000-micron mesh size). Quadrats at depths of 0.25 m to 1 m were sampled by the surveyor standing in the water, and quadrats at depths of 1.5 m to 3 m were sampled by the surveyor using SCUBA-diving gear to reach the desired depth