Effects of the Invasive Freshwater Mussel Limnoperna fortunei on Sediment Properties and Accumulation Rates

TOKUMON, ROMINA; BOLTOVSKOY, DEMETRIO; CATALDO, DANIEL

TRANSACTIONS-AMERICAN GEOPHYSICAL UNION

AMER GEOPHYSICAL UNION

Año: 2018

0002-8606

Since its introduction into South America around 1990, the freshwater bivalve Limnopernafortunei (the golden mussel) has spread rapidly and is now a dominant component of the benthic andperiphytic fauna in many rivers, lakes, and reservoirs. Sizable impacts of this nonindigenous species onnutrient recycling, plankton abundance and composition, and trophic relationships with fishes have beenreported, but its effects on the sediments have received little attention. In this work, we use eighteen 20-Lflow-through experimental units with and without mussels where changes in the mass and characteristics ofthe sediments accumulated throughout a yearly cycle in monthly, biannual, and annual intervals areanalyzed. Experimental units with mussels yielded almost 2 times more sediments than units withoutmussels and contained significantly higher loads of organic matter and total N. Total P was not affected bythe presence of mussels. Sediments accumulated in the biannual and annual experimental units agreed wellwith the yields of the monthly units, but the vertical stratification of organic matter, N, and P wasunpatterned. Seasonal changes in the volume of total sediments, biodeposits, and their organic matter and Ncontents were positively associated with ambient water temperature and with intermediate (~150?250 NTU,nephelometric turbidity units) turbidity. Our results suggest that ecosystem-wide modifications in theliving conditions of the benthic epifaunal and infaunal organisms in waterbodies invaded by the mussel arelikely significant, although variable locally, regionally, and across taxa.