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Updated: Aug 29, 2025
Quantifying Fish Swimming Behavior in Response to Acute Exposure of Aqueous Copper Using Computer Assisted Video and Digital Image Analysis
Published on: February 26, 2016
Beyond deep-sea mining sublethal effects: Delayed mortality from acute Cu exposure of the cold-water octocoral
Inês Martins1, António Godinho1, Maria Rakka1
1Institute of Marine Sciences - Okeanos, University of the Azores, Rua Professor Doutor Frederico Machado 4, 9901-862 Horta, Portugal; Instituto do Mar - IMAR, University of the Azores, Horta, Portugal.
Abstract:
The potential release of metals, especially copper (Cu) during mining of seafloor massive sulphides (SMS), represents a potential toxicological threat to cold-water coral (CWC) habitats. Herein, we evaluated for the first time the response of the whip coral Viminella flagellum to short-term acute Cu exposure. Nubbins of V. flagellum were exposed to Cu concentrations of 0 (control); 60; 150; 250; 450 and 600 μg/L for 96 h. After exposure, V. flagellum nubbins were transferred to a continuous flow-through aquarium and feed once a day for 3 weeks. No immediate mortality was detected during the short-term Cu exposure. However, a delayed mortality, which was concentration dependent was observed. The first signs of tissue loss occurred after 1 week of recovery in non-contaminated conditions in V. flagellum nubbins previously exposed to Cu concentrations of 60 and 150 μg/L followed by nubbins exposed to Cu concentrations of 250, 450 μg/L after 2 weeks and 600 μg/L after 3 weeks. A delayed mortality impact should be considered in future Cu tolerance experiments and scenarios of deep-sea mining exploitation.
