Davis Aerodrome Project (DAP) - A database of the microinvertebrate fauna of terrestrial and lacustrine habitats of the Vestfold Hills

Full description

The Davis Aerodrome Project (DAP) collected a range of environmental survey data over several field seasons to support a comprehensive environmental assessment of the proposed aerodrome. This data includes flora, fauna, soils, lake ecosystem, nearshore, marine, air quality and meteorological information which has been collected by a number of different methods, and extends across the current Davis Station, proposed aerodrome and supporting infrastructure footprint (Ridge Site), previous sites considered for the aerodrome (Heidemann Valley, Adams Flat), as well as locations across the Vestfold Hills away from any of the proposed developments.
The Vestfold Hills is one of the largest, ice-free coastal oases in Antarctica. The rocky landscape is dotted with numerous lakes, some of which receive meltwater from the Antarctic icesheet, and are ultrafresh. Other lakes owe their existence to the isolation of marine basins during isostatic rebound, and are now saline to hypersaline. In summer local meltstreams develop, and in moist places mosses and lichens can be abundant. All these habitats – lakes, soils, mosses and lichens – harbour a range of microinvertebrates, including species of nematode, tardigrade, monogonont and bdelloid rotifers, mites, copepod and cladoceran. The animals that inhabit the Vestfold Hills are highly adapted to their environment; many are able to survive being frozen for extended periods. The wide range of lacustrine habitats means that there a similarly wide range of species present. The Vestfold Hills are home to some species not recorded elsewhere, as well as unusual occurrences of marine species that survive in saline lakes.

The animals of the Vestfold Hills can also be viewed as part of a continent-wide biota, components of which had their origins prior to the break-up of Gondwanaland and the onset of Antarctic glaciation. Many species occur widely across the continent, while others have very limited distributions. Understanding Antarctic biogeography yields insights into the development of the physical geography of the continent.

Identification of the microinvertebrates can be difficult. While some species are immediately obvious, others cannot be identified purely on morphology. In particular, the bdelloid rotifers are renowned for being difficult to identify as many look similar, and they have a propensity to curl up into an unidentifiable ball. Modern DNA-based methods have markedly increase the number of species known to occur in the Vestfold Hills and throughout Antarctica. Furthermore, detailed genetic ‘barcodes’ based on a standardised section of the mitochondrial cytochrome c oxidase subunit 1 gene (CO1) indicate the presence of a range of haplotypes that provide a further level of detail.

This database provides all known records of free-living metazoan microinvertebrates from the Vestfold Hills. Records were extracted from published observations, the first of which were made on samples collected on a visit to the area by scientists from the Soviet Union in 1956. Many early identifications are to genus only, and should be viewed in this light. Limited detailed taxonomic publications appeared up until circa 2015. Modern, molecular genetic techniques were first applied to samples from the area in the early 2010s, which indicated far greater diversity than previously realised. A concerted lake and terrestrial sampling program associated with the Davis Aerodrome Project (DAP) provided numerous new direct observations, as well a multitude of DNA-based data.

This database represent the current state of knowledge as of 30 June, 2022.
Latitude Resolution:
Early terrestrial records often have poor spatial resolution, as data are only available from low-resolution maps. Modern samples (post-2000) typically have locations determined by GPS, and are therefore far more accurate. Locations of lakes are well known, and therefore all records from lakes have good spatial resolution in terms of lake location. GPS-determined sampling locations are available in general for samples collected post-2000.

Longitude Resolution:
See above

Vertical Resolution:
Surface altitude of the lakes was determined from a digital elevation model of the Vestfold Hills developed in the 1990s. This DEM is known to have problems in some areas.

Temporal Resolution:
The date of sample collection for samples collected as part of the DAP program are recorded in the database, but is poorly known for earlier samples. The date of analysis of the samples is not recorded.

A data update was provided on 2022-10-26.

Lineage

Progress Code: completed

Statement: Data was obtained from the following sources: 1. Published data. The quality of much of this data is uncertain, as many species cannot be identified purely from microscopic observations. Some publications, however, are the work of taxonomic experts (some describing new species), and these are of high quality. The original source is referenced for all published observations in the database, which are with a few exceptions (for which details are provided) given under the names recorded in the publications. 2. Direct observation of animals in samples collected during the DAP program. The taxa are listed at the highest taxonomic rank for which there is no doubt. 3. Molecular genetic data obtained by environmental DNA analysis, or by analysis of single animals sent to the Barcode of Life project (https://ibol.org/) for analysis. These data should be seen to be of the highest quality.

Notes

Purpose
This database lists all records of metazoan microinvertebrates from lacustrine and terrestrial habitats of the Vestfold Hills, as at 30 June, 2022. Assembly of this database aimed to bring together a comprehensive and current body of information on metazoan microinvertebrates in the Vestfold Hills for the purpose of inform environmental assessment processes being undertaken as part of the Davis Aerodrome and Davis Masterplan projects.