The impact of salinization on benthic macro-crustacean assemblages in a Mediterranean shallow lake

• Published in: Aquatic ecology 2024-09, Vol.58 (3), p.689-706
• Main Authors: Žganec, Krešimir, Andersen, C. Brannon, Lajtner, Jasna
• Format: Article
• Language: English
• Subjects: Active control; Adriatic Sea; Antennarius; Aquatic crustaceans; Benthos; Biodiversity; Biomedical and Life Sciences; Croatia; Crustaceans; Echinogammarus; Ecological effects; Ecological monitoring; Ecosystems; Freshwater; Freshwater & Marine Ecology; Gammarus; Information management; Inland water environment; Isopoda; Lake basins; Lakes; Life Sciences; Littoral environments; littoral zone; Long-term changes; Macroinvertebrates; Marine crustaceans; Palaemon; Population decline; population dynamics; Saline water; Salinity; Salinity effects; Salinization; Seawater; Shellfish; species; Water management; watersheds; Zoobenthos
• ISSN: 1386-2588; 1573-5125
• DOI: 10.1007/s10452-024-10099-1

The shallow Vrana Lake in Dalmatia, Croatia, is directly connected to the Adriatic Sea by the Prosika canal (0.85 km), constructed in the eighteenth century. The aim of this research was to examine the impacts of salinization on long-term changes in littoral macro-crustacean (Malacostraca) populations and assemblages in Vrana Lake and connecting canals. Benthic macroinvertebrates were sampled at seven sites during the period 2011–2020 (14 months) using a hand net (25 × 25 cm, 500 µm). During the study period, saltwater intrusions (strongest in 2012) through the Prosika Canal and site V4 caused increased salinization, resulting in a shift from normal oligohaline (0.5–5 PSU) to mesohaline (5–18 PSU) salinity. Out of a total of 18 macro-crustacean taxa identified, five widespread species—amphipods Echinogammarus stocki and Gammarus aequicauda , isopods Lekanesphaera hookeri and Proasellus coxalis , and decapod Palaemon antennarius constituted 91.6% of collected specimens (26,986). The first three brackish/marine species were significantly positively correlated with the average salinity 12 and 24 months before sampling. They disappeared or had very low abundance during the second low salinity phase (