Catalonia’s Natural Heritage and Biodiversity Observatory updates the territory’s Living Planet Index, which measures wildlife loss

Catalonia’s Natural Heritage and Biodiversity Observatory has recently published a new update to the LPI-Cat, the territory’s version of the Living Planet Index. The latest data show a 28% decline in the average size of wildlife populations in Catalonia between 2002 and 2023. Worldwide, the global LPI indicates that the average size of monitored wildlife populations — encompassing 5,495 species of amphibians, birds, fish, mammals and reptiles — has fallen by 73% in the last 50 years. In the case of Europe and Central Asia, calculations point to a 35% drop.  

The last previous update of the LPI-Cat took place in 2022. The new update provides a more accurate and reliable picture of the state of Catalonia’s wildlife populations, as it draws on information about more species and samples from more sites, thus modifying the values calculated in 2022.  

Specifically, the latest update to the index incorporates data on 353 species, 32 more than in 2022. The newly added species include the Valencia toothcarp (Valencia hispanica), a small fish endemic to coastal lagoons in Catalonia and the community of Valencia; mammals such as the barbastelle bat (Barbastella barbastellus) and the European badger (Meles meles); and the European common frog (Rana temporaria), an amphibian that lives in cold environments.  

Additionally, for the first time, the general trend of the LPI-Cat has been analysed to determine whether the rate at which the size of animal populations has decreased has sped up, slowed down or remained steady over time. The results point to the third option: although the rate of loss is not diminishing, it has not increased in recent years either, remaining at an annual average of 1.5% of specimens.  

“The Living Planet Index tells us whether the number of wild animals we have is increasing or decreasing,” explained CREAF researcher Sergi Herrando, scientific coordinator of the group of experts who calculate the index value as part of the work of the Natural Heritage and Biodiversity Observatory. “It is an average of the trends of many species, basically those for which we have enough quality information. The current version includes not only data from another two years but also information about new species of butterflies, mammals, and freshwater fish, in addition to incorporating more sites for reptiles, amphibians, and small mammals like bats. And, for the first time, we have been able to include marine species, thanks to marine biodiversity monitoring carried out at Cap de Creus and the Medes Islands.”  

Jordi Sargatal, the Government of Catalonia’s Secretary for Ecological Transition, described the LPI-Cat as “a key indicator for the Catalan Strategy for Natural Heritage and Biodiversity, as an assessment tool we can use consistently over time”. He stated the need to implement “ambitious objectives involving conservation policies that reverse this trend” and added that the Government of Catalonia’s Ministry of Territory, Housing and Ecological Transition is working to develop tools to that end, including a Nature Law and a Nature Agency, which it is hoped will be in place by mid-2025 and early 2026 respectively. 

The newly released data include information by environment type, which was updated and improved in 2024 after not having been published since appearing in the State of Nature in Catalonia report in 2020. The availability of more data has resulted in a clearer picture of the decline that has taken place in each environment type over the last 22 years, with falls of 40% in meadows and agricultural environments and in inland water environments, and 15% in forests and scrubland.  

Data on the marine environment are still limited to a handful of species and locations, so representative trends cannot be identified for all marine communities. However, the inclusion of marine species in the general indicators for the first time is a positive development.  

The newly introduced analysis of the general trend of the LPI-Cat improves scope for identifying and shaping policies geared to reversing wildlife loss. Populations of forest animals have been earmarked as a priority target for such policies, because although forest environments have been expanding and maturing in recent years, the loss of animals that inhabit them is accelerating. “That suggests that the implementation of conservation measures is being counteracted by growing pressure on the natural environment,” remarked Lluís Brotons, scientific coordinator of the Natural Heritage and Biodiversity Observatory. In the case of meadows and agricultural environments, in contrast, the trend observed has been less negative over the last 10 years, despite the overall decline. 

The causes of such variations in trends will need to be carefully studied in the coming years. As Jordi Sargatal pointed out, “conserving nature is urgent and in everyone’s interest; not doing so would entail far greater economic and social costs.”  

Although the average animal population size has fallen since the beginning of the century, a closer look reveals a wide variety of cases: there are 164 species with shrinking populations and 70 with growing populations, while the remaining 119 show no significant population trends.

The faunal groups in which declines are most generalized are fish and diurnal butterflies, with population numbers falling among almost 70% of species in each case. The numerous species of butterflies with dwindling populations include two typical of open Mediterranean environments: the black-eyed blue (Glaucopsyche melanops) and the western marbled white (Melanargia occitanica), the populations of which are in regression or have died out in many locations while increasing in none. In the case of fish, marine species like the white seabream (Diplodus sargus) and freshwater species like the Ebro barbel (Luciobarbus graellsii) are in regression.  

Among mammals, conversely, there are more species with growing than shrinking populations. The brown bear (Ursus arctos) and the European badger fall into the former category, and Schreiber’s bent-winged bat (Miniopterus schreibersii) and the long-tailed field mouse (Apodemus sylvaticus) into the latter. 

The LPI-Cat integrates time series data from 32 biological monitoring projects, which account for just over a tenth of the approximately 300 monitoring projects from which the Natural Heritage and Biodiversity Observatory’s HARMON (Harmonization of Biodiversity Monitoring) project has so far compiled data.  

The 32 projects in question are those with the best time series of population data and the widest spatial coverage. While more monitoring projects and species are gradually being added to the LPI-Cat, the data available from some monitoring initiatives, such as those involving plants, are not yet sufficiently consolidated and representative. Consequently, entire biological groups — one of which is plants — are currently absent from the index.  

A project launched by the Government of Catalonia’s Ministry of Territory, Housing and Ecological Transition and implemented through the territory’s Natural Heritage and Biodiversity Observatory, the LPI-Cat is coordinated by CREAF, the Catalan Ornithological Institute, the BiBio research group from the Granollers Museum of Natural Sciences, the University of Barcelona’s Biodiversity Research Institute (IRBio), and the Catalan Herpetological Society. The Government of Catalonia’s Ministry of Agriculture, Stockbreeding, Fisheries and Food also contributes to the project by providing data on game species.

This is the fourth update of the LPI-Cat, Catalonia’s version of an index originally created to measure global biodiversity loss by the World Wide Fund for Nature (WWF) and recognized by the United Nations. Catalonia is Spain’s only autonomous community with its own LPI, and the index value is a key piece of data in the Natural Heritage and Biodiversity Observatory’s periodic assessments of the territory’s biodiversity.  

The LPI-Cat is based on data from standardized biodiversity monitoring programmes, which are mainly organized by bodies that coordinate fieldwork and often implemented by volunteers with expert knowledge in the relevant areas. New species are only added to the index if information quality criteria are met and results are deemed representative of populations throughout Catalonia. All the contributing projects produce annual population counts (numbers of individuals) at sampling stations where periodic monitoring is carried out. The projects that provide the most information for the LPI-Cat are the Catalan Common Bird Survey (SOCC) and the Catalan Butterfly Monitoring Scheme (CBMS).

In 2024, nine projects were incorporated into the index. They included marine biodiversity monitoring projects in the Cap de Creus Natural Park and the Montgrí, Medes Islands and Baix Ter Natural Park; the QuiroRefugis and QuiroRius bat monitoring projects; the Catalan Common Amphibian Survey (SACC); and the Ministry of Agriculture, Stockbreeding, Fisheries and Food’s Mammal Monitoring Programme (for game species).