We spoke to PhD student Georgie Savage about her fieldwork investigating the impacts of chemical pollutants on giant tortoises and their habitats, and how her research can benefit conservation plans.
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What was the aim of your recent research trip to Galapagos, and who were the partners you worked with?
I had numerous aims for my most recent field trip to Galapagos, which was supported by Galapagos Conservation Trust, as I always want to make the most of the time I have on the Islands, connecting with as many partners and collecting as many samples as possible! Firstly, while working with the Galapagos Science Centre (GSC), I aimed to investigate the presence of pesticides and emerging contaminants of concern in urban coastal areas around the three main inhabited islands, utilising rapid assessment techniques. A contaminant is quite literally anything that should not be where it is found – they can be synthetic or naturally occurring substances that are not yet monitored or widely regulated but are suspected of posing a risk to human or environmental health. This research project was part of the permit granted under GSC (PC-52-24).
Secondly, in collaboration with the Charles Darwin Foundation (CDF) and the Giant Tortoise Movement Ecology Programme, we hoped to characterise heavy metals and emerging contaminants in highland ponds from different land-use categories (e.g., agricultural land, the Galapagos National Park and tourist ranches) on Santa Cruz island.
Thirdly, we wanted to assess the exposure of Galapagos giant tortoises, which wallow in these ponds and migrate through the different land-use categories, to emerging contaminants, using passive samplers. Passive samplers are devices that can measure contaminants in different environmental matrices (water, sediment, air) through the natural diffusion of substances onto a sorbent material over time. This research project was part of the permit granted under CDF (PC-28-24).
All of this work was done in coordination with the Galapagos National Park Directorate, with Park Rangers often joining us in the field.
Where are the chemical pollutants you are detecting in ponds and coastal areas coming from, and how are they infiltrating these environments?
Unfortunately, despite the geographical remoteness of the Galapagos Archipelago, which is approximately 1000 km off the coast of mainland Ecuador, in the middle of the Eastern Pacific Ocean, the Islands have not escaped the ‘Great Acceleration’ – a term used to describe the dramatic increase in human activities, including urbanisation, industrialisation and globalisation, since the mid-20th century.
The Galapagos Islands are under pressure from their growing agricultural, shipping, fishing and tourism industries, which are heightening their exposure risk to chemicals such as pesticides, oil, emerging contaminants, heavy metals and plastic. Furthermore, the cumulative influence of Galapagos’ equatorial position amongst major atmospheric and oceanic currents, along with distinctive environmental conditions such as extreme sunlight (UV radiation) and rainfall, is likely exacerbating the Archipelago’s susceptibility to chemicals from both local and continental inputs, as well as driving their transport and distribution to different environments.
What impact could these pollutants have on tortoises and other species?
We don’t yet have the answer to this question, but it will very much depend on the environmental concentrations the Galapagos giant tortoises are exposed to, which is what we’re currently trying to find out. Scientific evidence suggests that chemicals can have an array of health, behavioural and reproductive impacts on animals, which can range from subtle changes in individuals to dynamic effects on whole populations.
For example, exposure to chemicals can weaken the immune system, increase disease susceptibility, disrupt hormones, impair development, reduce fertility, alter neurological function and change social interactions.
Research, partly funded by GCT, has found that tortoises in Galapagos are ingesting plastic.
What are some of the challenges you face when conducting research in the field?
I think one thing I’ve learnt when conducting fieldwork in Galapagos is to have a plan A, B, C, D and Z! You can never fully anticipate the challenges you might face in the field until you are on the ground and experiencing them. The key to fieldwork is getting creative, problem-solving and being able to quickly adapt.
The extreme weather conditions are an inevitable challenge we have to adapt to in Galapagos, especially when at sea or up in the highlands. One minute it’s boiling and you’re sweating buckets, and then the next there’s a torrential downpour and you’re soaked! The rough sea can be interesting and prevent us from accessing certain sites, meaning we often have to swim ourselves and our kit there. Navigating the dense high and low land vegetation and sharp and slippery lava rock terrain can also be a real obstacle – a machete really is your best friend in this situation! The mosquitoes and horseflies are a constant battle, especially when you can’t wear insect repellent because it’ll contaminate your samples!
How could this research be used to help protect Galapagos species and habitats?
We are hoping to develop a toolkit of techniques, equipment and methods to help rapidly assess and monitor chemical contaminants in Galapagos. The data from this fieldwork will enable us to identify point sources of pollutants and chemical hotspots, where mitigation and management strategies can be implemented by the Galapagos National Park Directorate.
Furthermore, it will allow us to conduct environmental risk assessments to identify the species most at risk from chemical contaminants and thereby target our interventions. Once we have evidence of presence and impact, we can then open dialogue channels with farmers, fishermen and other stakeholders to try to navigate the current trade-off between the ‘Great Acceleration’ and the conservation of Galapagos.
Adopt a Galapagos giant tortoise today and help to protect this species, their habitats and other Galapagos wildlife.
