Biology subjects

Hallett, M. T.

Publications and source records attributed to Hallett, M. T..

2 recordsLinked to original sources

bioRxiv2021

A metagenomic-based stufy of two sites from the Barbadian reef system

We study the microbiome of sea water collected from two locations of the Barbadian coral reefs. The two sites differ in several environmental and ecological variables including their endogenous benthic community in addition to their proximity to urban development and runoffs from inland watersheds. The composition of the microbial community was estimated using whole genome DNA shotgun sequencing. Although both sites exhibit a similar degree of richness, the less urbanized site (Maycocks reef at Hangmans Bay) is strongly concentrated with phototrophs. In comparison, the more urbanized location (Bellairs Research Institute) is enriched for copiotrophs, macroalgal symbionts and marine-related disease-bearing organisms from taxa scattered across the tree of life. Overall, our samples and associated measurements of chemical and environmental qualities of the water are in line with previous marine microbiome profiles of warm ocean surface waters. This suggests our approach captures salient information regarding the state of each coral reef site and sets the stage for larger longitudinal studies of coral reef dynamics in Barbados.

microbiology↗

bioRxiv2020

Mysterious disappearances of a large mammal in Neotropical forests

The drivers of periodic population cycling by some animal species in northern systems remain unresolved1. Mysterious disappearances of populations of the Neotropical, herdforming white-lipped peccary (Tayassu pecari, henceforth "WLP") have been anecdotally documented and explained as local events resulting from migratory movements or overhunting2,3,4, or as disease outbreaks5,6, and have not been considered in the context of large-scale species-specific population dynamics. Here we present evidence that WLP disappearances represent troughs in population cycles that occur with regular periodicity and are synchronized at regional and perhaps continent-wide spatial scales. Analysis of 43 disappearance events and 88 years of commercial and subsistence harvesting data reveals boom - bust population cycles lasting from 20 to 30 years, in which a rapid population crash occurring over 1 to 5 years is followed by a period of absence of 7 to12 years and then a slow growth phase. Overhunting alone cannot explain the crashes, but as in northern systems dispersal during the growth phase appears to play a key role. This is the first documentation of population cycling in a tropical vertebrate.

ecology↗