Quantifying regional biodiversity in the tropics: A case study of freshwater fish in Trinidad and Tobago

• Published in: Biotropica 2019-09, Vol.51 (5), p.700-708
• Main Authors: Jones, Faith A. M., Rutherford, Mike G., Deacon, Amy E., Phillip, Dawn A. T., Magurran, Anne E.
• Format: Article
• Language: English
• Subjects: Anthropocene; assemblage composition; Biodiversity; Collection; Composition; Data; Data collection; Datasets; Estimates; extrapolation; Fish; Fresh water; Freshwater; Freshwater fish; Freshwater fishes; Inland water environment; Literature reviews; Museum collections; Museums; Neotropics; Polls & surveys; Rarefaction; Regional analysis; Rivers; Species diversity; Species extinction; Species richness; Surveying; Surveys; Tropical climate; Tropical environments; Zoology
• ISSN: 0006-3606; 1744-7429
• DOI: 10.1111/btp.12692

Extinction rates are predicted to accelerate during the Anthropocene. Quantifying and mitigating these extinctions demands robust data on distributions of species and the diversity of taxa in regional biotas. However, many assemblages, particularly those in the tropics, are poorly characterized. Targeted surveys and historical museum collections are increasingly being used to meet the urgent need for accurate information, but the extent to which these contrasting data sources support meaningful inferences about biodiversity change in regional assemblages remains unclear. Here, we seek to elucidate uncertainty surrounding regional biodiversity estimates by evaluating the performance of these alternative methods in estimating the species richness and assemblage composition of the freshwater fish of Trinidad & Tobago. We compared estimates of regional species richness derived from two freshwater fish datasets: a targeted two year survey of Trinidad & Tobago rivers and historical museum collection records submitted to The University of the West Indies Zoology Museum. Richness was estimated using rarefaction and extrapolation, and assemblage composition was benchmarked against a recent literature review. Both datasets provided similar estimates of regional freshwater fish species richness (50 and 46 species, respectively), with a large overlap (85%) in species identities. Regional species richness estimates based on survey and museum data are thus comparable, and consistent in the species they include. Our results suggest that museum collection data are a viable option for setting reliable baselines in many tropical systems, thereby widening options for meaningful monitoring and evaluation of temporal trends. in Spanish is available with online material. Resumen Se prevé que las tasas de extinción acelerarán durante el Antropoceno. La cuantificación y mitigación de estas extinciones requieren de datos sólidos sobre las distribuciones de las especies y la diversidad de taxones en las biotas regionales. Sin embargo, muchas asociaciones biológicas, particularmente aquellas que se encuentran en los trópicos, están escasamente caracterizadas. Los muestreos dirigidos y las colecciones históricas de museo están siendo utilizados cada vez más para satisfacer la necesidad urgente de disponer de información precisa, pero todavía no está claro hasta qué punto estas fuentes de información contrastantes apoyan inferencias significativas sobre el cambio de la biodiversidad e