Project

New Conservation Methodologies

The Patagonia Program aims to conserve the environments and species of Patagonia through solid strategies, thought in an integral way through the generation of knowledge. This allows us to work in an adaptive way, continuously improving our actions. Currently, technological development allows us to work with techniques that until recently were very costly both logistically and economically. That is why our objective is to propose actions that allow us to collaborate with those groups that provide us with tools that will make our conservation programs more efficient. Satellite image monitoring (using new analysis tools, such as AI), increasingly modern transmitters and molecular techniques, among others, are the strategies we are addressing.

patagonia in action program

Lines of research

Monitoring of endangered species in Patagonian freshwater systems using environmental DNA techniques

Responsible

Graciela Obregón

State

Active

Introduction

Environmental DNA is the genetic material that can be extracted directly from environmental samples such as water, soil, air. This genetic material (DNA) is released into the environment from tissue debris, hairs/feathers, among other excretions and secretions. Environmental DNA sampling is a technique that allows the detection of species. It is a non-invasive method that is very useful to analyze the presence of elusive species or few individuals, which are difficult to detect with traditional techniques. This, together with other traditional field survey methods, such as the search for tracks, will allow us to update the distribution of the species under study. We also use camera traps to obtain information on their habits and activity patterns.

Target

The objective is to test the use of modern techniques to generate rapid detection tools of lower logistical and economic cost to obtain updated information on the distribution of species with which we already work in the program. These species inhabit different types of Patagonian freshwater systems, such as the Huillín, the Torrent Duck and the Little Redfish. For this we apply environmental DNA molecular techniques and classical monitoring methodologies and compare the probability of detection of these different methodologies.

methodology

To achieve our objectives, we developed a set of species-specific primers that allow us to amplify diagnostic fragments of environmental DNA for each of the species. But first, it is necessary to conduct field work throughout western Patagonia, from Neuquén to Santa Cruz. Sampling sites include seven national parks and many other nearby localities. For each of the species we work in ten water systems (rivers, lakes or lagoons as appropriate for each species we work with). In each system we define between one to five sampling sites separated by 10 km, 5 km and 1 km depending on the area of action of each species. At each sampling site, between one and ten liters of water are collected in triplicate in sterile plastic bottles. The water samples obtained are filtered in the field, and each filter will be preserved separately for subsequent DNA extraction. Also at each site, the presence of the species is evaluated based on specific non-invasive methodologies for each one. For example, for the Huillín, a 600 m transect is walked in search of traces (feces or footprints). In the Torrent Duck sampling sites, a distance of 1 km is covered to visually record individuals. Finally, in systems with possible presence of Redfish, the playback technique is used. For the extraction of DNA from each filter, work is carried out in the laboratory. Subsequently, and independently for each study species, the DNA obtained is used to test the PCR amplification of mitochondrial fragments, using previously selected primers. The sequences obtained by PCR amplification are compared with those previously obtained from tissue samples in order to verify that the amplified and sequenced DNA corresponds to the study species. Additionally, the efficiency of the aDNA technique is statistically compared taking into account the characteristics of the different water bodies and the efficiency compared to other non-invasive sampling techniques.

partners

- Molecular Ecology Research Group (GIEM), which is part of the Institute of Ecology and Sustainable Development (INEDES-UNLu-CONICET).

results and progress

Within the framework of the project, we have managed to develop and optimize the application of species-specific primers for the amplification of mitochondrial DNA obtained from environmental DNA samples for each of the study species. In addition, during the first months of the year 2023 we have carried out a first sampling campaign that will allow us to fine-tune the technique for obtaining and extracting aDNA. The project has no results or publications yet.

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