Brazil’s Unexpected Spike in Non‑Native Mollusks
A recent study published in the journal Biological Invasions reveals that Brazil now hosts at least 82 alien mollusk species, a three‑fold increase over the 26 species recorded just a decade ago. The surge represents a more than 200 % rise in a surprisingly short period, prompting scientists to warn that many of these newcomers may become ecological troublemakers.
Where the invaders are found
Researchers divided the country’s habitats into three categories: marine and coastal waters, freshwater systems, and terrestrial environments. They identified 32 non‑native species along the seashore, 17 in rivers, lakes and ponds, and a striking 33 on land. In addition, twelve species have uncertain origins, underscoring how little is still known about the full composition of Brazil’s alien mollusk community.
From harmless hitchhikers to destructive pests
Not every introduced species wreaks havoc. Some settle without noticeable impact, while others thrive under controlled conditions such as farms or aquaria. The real concern emerges when a population establishes itself in the wild, reproduces successfully, and begins to damage ecosystems, economies, or public health. At least twenty of the identified species already meet the criteria for being invasive.
Iconic offenders
The golden mussel (Limnoperna fortunei)—likely native to China—has become a textbook case of rapid expansion. First observed in Brazil in the early 1990s, it now blankets countless waterways across South America. Its prolific fouling of water‑intake pipes has crippled hydro‑electric plants and cooling systems, costing the Brazilian government roughly ten million dollars in futile control attempts.
Another notorious newcomer is the giant African land snail (Lissachatina fulica). Imported as a potential escargot crop, the venture collapsed, releasing thousands of snails into agricultural zones. These herbivores devour a wide range of crops and also serve as vectors for a parasitic worm that can cause meningitis in humans.
Knowledge gaps and policy challenges
“We discovered that Brazil has become dramatically richer in exotic mollusks, yet for many of them we still lack basic information,” says lead author Marcel Sabino Miranda. The study highlights a pressing need for systematic monitoring, rapid identification, and risk assessment frameworks. Without such tools, distinguishing harmless arrivals from future invaders will remain a guessing game.
Improved border inspections, public awareness campaigns, and targeted research funding could halt the tide of new introductions. In the meantime, the existing invasive species continue to test Brazil’s biodiversity resilience and economic stability.
Source: https://scientias.nl/brazilie-telt-ineens-ruim-drie-keer-zoveel-uitheemse-weekdiersoorten/
