Data underlying the publication: Distribution and diversity of benthic macroinvertebrates in the selected Myristica swamps of Kulathupuzha and Shendurney

Myristica swamps, unique tropical freshwater ecosystems of the Western Ghats, are rich in biodiversity and critical habitats for benthic macroinvertebrates. This study assessed their population dynamics, diversity, and ecological indices in Kulathupuzha and Shendurney, focusing on environmental factors such as water and sediment quality, forestry activities, and seasonal variations. Macroinvertebrates were analyzed using PCA, indicator analysis, and correlation analysis to evaluate their relationship with physicochemical parameters like dissolved oxygen, pH, and nutrients. Kulathupuzha exhibited higher macroinvertebrate density (8,438.95 ind/m²) than Shendurney (7,420.36 ind/m²), with pollution-sensitive species like Odonata, Trichoptera, and Plecoptera indicating good water quality. Seasonal variations influenced species abundance, with pre-monsoon showing the highest density (7,703.26 ind/m²). These findings highlight the need for ongoing monitoring to manage environmental impacts and support conservation efforts in these vital ecosystems.Water samples were collected bimonthly from eleven sites during pre-monsoon, monsoon, and post-monsoon seasons (2021–2023) in sterile bottles and stored at 4°C for analysis. Physicochemical parameters of water and sediment were analyzed using standard methods (Wetzel & Likens, 1991; APHA, 2012). Sediment samples (0–10 cm depth) were collected for parameters like pH, organic carbon, and heavy metal analysis via AAS. Benthic macroinvertebrates were sampled using a standard net, identified to the family level using field guides, and further classified in the lab using stereomicroscopes and taxonomic keys.