From butterflies to seagrass... discover the biodiversity indicators guiding the future of sustainable development

As nature faces increasing pressures from biodiversity loss, climate change and pollution, tracking how ecosystems are changing – and how this affects society – is needed now more than ever. But measuring biodiversity and nature’s contributions to people (NCPs) is notoriously complex. 

However, a project report – as part of the EU-funded GUARDEN project (safeGUARDing biodiversity and critical ecosystem services across sectors and scales) – led by PML’s Dr Stefanie Broszeit, sets out a robust framework to help researchers and policy teams select the most relevant, reliable, and practical biodiversity indicators for their needs.  

What are biodiversity indicators? 

Biodiversity indicators are measurable tools used to track the state of nature. They reflect key aspects of biodiversity – such as species populations, ecosystem condition, or genetic diversity – and help us understand how these are changing over time. By providing clear, evidence-based insights, biodiversity indicators support better decisions for conservation, policy, and sustainable development. 

The indicators – spanning marine, terrestrial, and freshwater areas – are tailored to real-world case studies in France and Madagascar, Greece, Cyprus and Spain. The main mission of the GUARDEN project is to safeguard biodiversity and its contributions to people by bringing them to the forefront of policy and decision-making. Therefore, each case study site was chosen because it highlights a “conflict” between nature conservation and human infrastructure development, a typical situation all over the world. The question in these areas is the same: what is the effect of developing infrastructure on flora and fauna, especially endemic species and habitats, under the EU Habitats Directive. 

The report outlines a carefully curated list of 154 scientifically rigorous indicators, drawn from an initial pool of over 800 that had been deemed relevant to the case studies, from existing indicators published in the Global Biodiversity Framework of the Convention of Biological Diversity, the Intergovernmental Science Policy Platform on Biodiversity and Ecosystem Services, the United Nations Sustainable Development Goals, the Convention on Biological Diversity, as well as regional (for example EU indicators), and national indicators.     

These indicators span ecological health, human wellbeing, and policy progress – and many spotlight species and ecosystems that people deeply care about. 

Each selected indicator was assessed on the merits of measuring aspects of biodiversity and NCPs relevant to the case study sites. A sample of the indicators that were matched with NCPs include: 

Other indicators are useful to measure pressures on ecosystems and people, for example the number of heat islands in a city or changes to the acidity (measured as pH) of seawater 

These include measuring pressures from tourism, infrastructure and energy development, as well as habitat condition, bird and butterfly populations, and local perceptions of nature. 

The GUARDEN team worked directly with local stakeholders in each case study to create bespoke indicator sets that reflect site-specific biodiversity challenges and development pressures. They checked with stakeholders of the project which of these indicators they already use and which ones they would be interested in. This way, it allowed stakeholders to consider using indicators that they have not yet come across. Their responses also provided the research team with a better understanding of what indicators that stakeholders already use can provide data for global ecosystem assessments such IPBES, SDGs, and CBD.  

“We wanted to include indicators that reflect not just what nature is, but what it means to people,” said Dr Broszeit. “From sea turtles to seagrass, these are the threads that connect ecological change to people’s lives and livelihoods.” 

Further information on other work carried out in GUARDEN includes: 

• MINKA: a citizen science platform for collecting biodiversity and environmental data, with a focus on the Sustainable Development Goals (SDGs). Find out more and get involved >> 

• An API for AI species recognition: species identification of birds using their birdsong >> 

• Nature Today | A birdsong AI joins the world’s biggest bird sound forum 

More information can be found on the GUARDEN website here >>