Large and fine-scale biodiversity patterns of marine and terrestrial fauna across wide-spread, fragmented territories: assessing inherent challenges of data scarcity.
Published in Scientific Reports (Springer Nature), 2025
✦ Abstract
The ongoing biodiversity crisis calls for a complete biodiversity inventory of marine and terrestrial ecosystems. The task is particularly challenging for fragmented island territories, where baseline biodiversity information is often difficult to procure. By centralising information from different sources (museums, research institutions, citizen scientists), 'big-data' platforms provide an opportunity to evaluate species biodiversity information of understudied regions.
Using data primarily sourced from the Global Biodiversity Information Facility (GBIF), and complemented by a review of 56 potential data sources — of which nine provided unique, non-redundant records — we curated the first biogeographic dataset for both marine and terrestrial animal species in French Polynesia, a territory of 124 islands and atolls in the Central Pacific, a marine biodiversity hotspot facing pressing conservation challenges.
The dataset revealed heterogeneous species richness across archipelagos and islands. Inventory completeness ranges from 1.9 to 98.4%, suggesting that a large proportion of the studied area remains poorly documented. Spatial and temporal sampling biases were partly explained by accessibility constraints (proximity to airports, roads or ports), and completeness was higher for marine than terrestrial species.
Our database identifies taxa and locations requiring urgent attention, and highlights well-documented species that can serve as indicators of environmental degradation. Explicitly acknowledging the inherent biases of biodiversity datasets is the first step towards a more comprehensive characterisation of species diversity across fragmented territories — crucial for sound adaptive-management and conservation planning.