Reconstructing the Holy Loch Ecosystem: The Holy Loch Food Web Project A foundational framework for a long-term ecosystem census integrating barcoding, environmental DNA, classical taxonomy, and niche architecture.

The Holy Loch Food Web Project has the single aim of clarifying all of the definable taxa and their associated ecological niches in our entire ecosystem comprising sea loch, saltmarsh, temperate rainforest, vegetated shingle, carr woodland and freshwater swamp. Although a simple idea, in reality, there are huge numbers of hurdles to get there. This note founds the whole project which will comprise, probably, hundreds of checklists from fungal, plant and animal taxa, updated as results from ongoing DNA barcoding via UK BIOSCAN led by the Wellcome Sanger Centre, eDNA metabarcoding and updated taxonomic understanding continue to clarify my simple species inventory. The project has no obvious end point. At the time of writing on 30th December 2025, the total number of eukaryote species listed at the Holy Loch exceeds 3000, and that is before we embark on eDNA techniques for soil fungi and large, unexplored taxa such as Nematoda. I expect the number of species to increase significantly in future.