Fisheries Society of the British Isles

PhD Studentships: Ada F. Eslava

PhD Student Ada Eslava (2020-2023)

(Supervisor(s): Anne Magurran (University of St Andrews), Amy Deacon (University of the West Indies, St. Augustine) and Indar Ramnarine (University of the West Indies, St. Augustine))

Biodiversity Change in Fish Communities: Integrating Taxonomic, Phylogenetic and Functional Diversity


Freshwater fish are among the most vulnerable organisms on the planet due to the ecological impacts of the multiple anthropogenic pressures that modify freshwater habitats. Despite the concern over the current state of the world’s freshwater fish faunas, little is known about how multiple facets of their diversity are changing over time.

In the tropics, the situation is particularly unclear because, historically, fewer temporal community data have been collected than in temperate locations. The tropical  island of Trinidad in the Caribbean is an exception, as stream fish communities there have been monitored at different time points during the last half-century.

In my project, I will ask two main questions. First, how has the regional freshwater fish diversity in Trinidad changed since the 1950s? Second, are the spatio-temporal patterns found in this tropical island observed in other locations of the world?

In order to answer my first question, I will extend time-series surveys by re-visiting fieldwork sites throughout the geography of Trinidad and use the records from the past to establish comparisons. To tackle the second, I will use open-access, temporal data of freshwater fish communities available in repositories such as BioTIME (

Since biodiversity is a multi-faceted concept, I will adopt a multi-dimensional  approach in my analyses. First, I will quantify two biodiversity components: the local diversity of communities and compositional change relative to a temporal baseline (also named alpha and temporal beta diversity). Second, I will use recently developed methodologies that integrate the information contained in species traits and phylogenies to measure the functional and phylogenetic dimensions of diversity alongside their taxonomic counterpart.

I’ll carry out this research at the University of St Andrews and the fieldwork at the University of the West Indies, Trinidad.


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