Impacts of the Invasive Seaweed Asparagopsis armata Exudate on Energetic Metabolism of Rock Pool Invertebrates

The marine red algae <i>Asparagopsis armata</i> is an invasive species gaining competitive advantage by releasing large amounts of toxic compounds to the surrounding invaded area. The main objective of this study was to evaluate the effects of this invasive seaweed on marine invertebrates by exposing the common prawn <i>Palaemon elegans</i> and the marine snail <i>Gibbula umbilicalis</i> to the exudate of this seaweed. The seaweed was collected and placed in a tank for 12 h in the dark in a 1:10 ratio. Afterwards the seawater medium containing the released secondary metabolites was collected for further testing. Lethal and sublethal effects of <i>A. armata</i> were investigated. Biochemical biomarker responses associated with energy metabolism (lactate dehydrogenase, LDH; electron transport system activity, ETS; lipid, protein and carbohydrate content) were analysed. The biomarker responses showed physiological status impairment of invertebrates after exposure to low concentrations of this algal exudate. The highest concentrations of exudate significantly increased lipid content in both organisms. In the shrimp, protein content, ETS, and LDH were also significantly increased. By contrast, these parameters were significantly decreased in <i>G. umbilicalis</i>. A behavioural impairment was also observed in <i>G. umbilicalis</i> exposed to <i>A. armata</i> exudate, reducing feeding consumption. These results represent an important step in the research of natural toxic exudates released to the environment and prospective effects of this seaweed in invaded communities under increasing global change scenarios.

This study had the support of Fundação para a Ciência e a Tecnologia (FCT) through the Strategic Project UID/MAR/04292/2020, project MARINE INVADERS—The impact and mechanisms of success of the invasive seaweed Asparagopsis armata on coastal environments (POCI-01-0145-FEDER-031144), and grant awarded to Carla Silva (SFRH/BD/87030/2012), and was also partially funded by Portuguese National Funds, FEDER funds within the PT2020 Partnership Agreement and Compete 2020-Programa Operacional Factores de Competitividade, and by the Portuguese Foundation for Science and Technology (FCT) through the strategic programme (UIDB/50017/2020 + UIDP/50017/2020). The project was also partially funded by the European Union through EASME Blue Labs project AMALIA—Algae-to-MArket Lab IdeAs (EASME/EMFF/2016/1.2.1.4/03/SI2.750419) and Integrated Programme of SR&TD “SmartBioR” (reference Centro-01-0145-FEDER-000018) cofunded by Centro 2020 program, Portugal2020, European Union, through the European Regional Development Fund.

Peer reviewed