Research Insights

Freshwater environments cover less than 1% of the Earth's surface, yet they support around 6% of global biodiversity. Tropical freshwaters are particularly rich — but they are also among the most vulnerable habitats on the planet. Deforestation, dam construction, and the conversion of forest to agricultural land for crops such as oil palm are rapidly and irreversibly altering rivers, lakes, and wetlands across the tropics, causing severe declines in native species.

Freshwater mussels sit at the heart of these ecosystems. As filter-feeders, they draw water through their bodies, removing particles including algae, bacteria, and chemicals, and releasing nutrients back into the water column and sediment. This process keeps water clear, supports food webs, and provides structure to riverbeds. Despite performing these essential services, freshwater mussels are among the most threatened groups of animals on Earth — and in tropical regions, they remain almost entirely unstudied.

Tabitha's research at the University of Nottingham is addressing this gap directly. In the laboratory, she has been measuring how the filter-feeding behaviour of native mussel species collected from pristine rivers in Borneo affects nutrient dynamics — and how that behaviour changes under rising temperatures. These are among the first experiments of their kind anywhere in the region, and the first ever conducted using these species.

In the field, the research combines traditional survey methods — hand-sampling for mussels and kick-net sampling for invertebrates — with cutting-edge molecular approaches. Environmental DNA (eDNA) is collected from water samples and sediment cores, capturing genetic material shed by all organisms present in a system. This is then extracted and analysed using DNA metabarcoding, allowing researchers to assess not just mussel distributions but the full range of associated biodiversity across a heavily altered landscape.

Together, the lab and field strands of research aim to build a picture of how environmental change affects the functional dynamics of tropical freshwaters — generating baseline knowledge that can be used to develop strategies to mitigate human impacts and safeguard the biodiversity and ecosystem services these rivers provide.

Public Engagement

This animation was produced to communicate Tabitha's research to a broad audience spanning researchers, conservationists, local stakeholders, and the general public. It is designed to be accessible to viewers with little or no prior scientific background, while remaining substantive enough for use in academic and policy settings. A particular aim is to open dialogue with communities and stakeholders in the regions studied, who may have valuable local knowledge about mussel distributions but limited awareness of their ecological significance.

This is one of a series of animations produced for Envision PhD researchers. Envision runs a competition in which early-career researchers submit a brief for an animated film; selected winners have their research brought to life through professional animation.