Líffræðifélag Íslands - biologia.is
Líffræðiráðstefnan 2025
Erindi/veggspjald / Talk/poster V65
Höfundar / Authors: Sigríður Vala Finnsdóttir (1), Joana Micael (1), Sindri Gíslason (1)
Starfsvettvangur / Affiliations: 1. Náttúrustofa Suðvesturlands
Kynnir / Presenter: Sigríður Vala Finnsdóttir
In 2019, the non-indigenous razor clam Ensis terranovensis Vierna & Martínez-Lage, 2012 (Mollusca; Pharidae) was discovered in Icelandic waters, presumably introduced as larvae via ballast water. This represents the first record of the species outside its native distribution in Newfoundland, Canada. However, the species remains poorly studied, and its biological traits are largely unknown. Its closest relative, Ensis leei, has proven highly opportunistic in European waters, where it has proliferated rapidly and altered habitats, providing insight into how the presence of E. terranovensis might develop in Icelandic waters. To evaluate its role in Icelandic coastal ecosystems and predict future population dynamics, age is a critical variable. Given prior challenges in interpreting external growth increments in Ensis species, this study aimed to evaluate whether more cost-effective and time-efficient methods can identify growth increments as accurately as more labour-intensive methods. Four methods were evaluated: two based on external increments (direct method, image method) and two on internal increments (section method, acetate peel method). Comparing these methods provides insight into their accuracy, precision, and applicability for E. terranovensis, offering a basis for future studies on its population ecology and potential impacts on coastal ecosystems as a non-indigenous species in Icelandic waters.