Invasive Species Threaten Galapagos Ecosystem Amid Climate Change

In the Galapagos Islands, the introduction of the Fowlers snouted treefrog, scientifically known as Scinax quinquefasciatus, poses a significant threat to the native wildlife, particularly as the region grapples with the compounded challenges of climate change and human impact.

According to The Guardian, these frogs arrived in the late 1990s, likely as stowaways on cargo ships from mainland Ecuador. Initially, the Galapagos, known for its unique biodiversity including giant tortoises and marine iguanas, was free from amphibians.

However, the invasive frogs have now established a substantial presence on the islands of Isabela and Santa Cruz, with populations estimated in the hundreds of thousands. Biologist Miriam San Jose from the Charles Darwin Research Station noted that their numbers are so vast that traditional tracking methods have proven ineffective, with estimates suggesting as many as six thousand frogs in a single pond.

Local farmers have expressed concerns about the disruptive noise from the frogs, especially during the wet season, as their mating calls can be overwhelming. However, the noise is not the main issue; scientists are more concerned about the ecological impact these frogs are having on the islands.

The Galapagos already hosts 1,645 invasive species, which threaten its delicate ecosystems, and the addition of these frogs could be particularly damaging. A study from 2020 indicated that the frogs are voracious insectivores, potentially consuming rare insects that are endemic to the islands, thus disrupting local food chains.

Ecologist Maria del Mar Moretta-Urdiales warned that their diet could also affect pollination, as they predominantly eat moths. Moreover, these frogs display unusual adaptability, being able to thrive in brackish water and showing varying metamorphosis rates, with some tadpoles remaining in their larval state for up to six months.

San Jose is apprehensive that the tadpoles might impact freshwater resources, which are already limited in the Galapagos. Historical attempts to control frog populations, such as hand capturing and salinity adjustments in lagoons, have largely been unsuccessful.

Alternative methods like using toxic substances or electrocution could harm other vulnerable species. San Jose emphasizes the need for further research to understand the frogs' biology and their ecological role before implementing control measures.

However, securing funding for such research has proven challenging, as most funding is directed toward preserving native species rather than controlling invasive ones. The situation in the Galapagos exemplifies the difficulties faced in biodiversity conservation, especially in the context of climate change and human activity, as invasive species continue to threaten unique ecosystems.