Caves or tree houses? For tropical diatoms, the choice hardly matters, according to new study
Research Matters Staff Writer(s) Pune 8 Aug 2026 A new study has found that diatoms, a vital biological indicator of river health, are much less picky about their homes than previously believed. The research, from Agharkar Research Institute, Savitribai Phule Pune University, and the Canadian Museum of Nature, Canada, shows that these microscopic algae exhibit almost no preference for growing on…
A new research study has revealed that tropical diatoms, which are crucial indicators of river health, are far less selective in their living environments than previously thought. Conducted by a team from Agharkar Research Institute, Savitribai Phule Pune University, and the Canadian Museum of Nature, the investigation found that these microscopic algae exhibit little preference between housing on submerged rocks or on aquatic plants.
This flexibility could greatly simplify the sampling process for monitoring river pollution in tropical regions. Diatoms are single-celled algae enclosed in silica shells, with different species often exhibiting specific tolerances to pollution, acidity, and nutrients. Traditionally, researchers have focused on sampling diatoms from specific surfaces, such as rocks, due to differences observed between rock-dwelling and plant-dwelling diatom communities.
However, the new study in tropical Western Ghats, a biodiversity hotspot, challenges this notion. By analyzing 40 sites across the region, the research team discovered that diatom communities on both surface types were remarkably similar. Factors like phosphorus levels, water temperature, and electrical conductivity appeared to have a much greater influence on diatom communities than the type of surface they were attached to.
In the Western Ghats, naturally high phosphorus levels and stable tropical temperatures seem to create a biological filter that determines diatom survival, regardless of the surface they inhabit. The study also highlighted the region's unique biodiversity, with over 57% of diatom species being endemic to the area. This endemism is much higher compared to European or North American rivers.
With increasing pressures from urbanization, agriculture, and climate change in the Western Ghats, the study emphasizes the importance of substrate-independent monitoring techniques. This means researchers can now accurately assess river health using whatever surface diatoms inhabit, even in challenging conditions like silty rivers or fast-flowing streams.
This flexibility in monitoring makes it easier for local communities and conservationists to keep a close eye on water resources, ensuring the preservation of this region's unique biodiversity for future generations.
Written by urgent.news from Research Matters India's reporting — not their text. Machine-written — it may contain errors, so check the original before relying on it.
