Filtration of the Microalga Amphidinium carterae by the Polychaetes Sabella spallanzanii and Branchiomma luctuosum: A New Tool for the Control of Harmful Algal Blooms?

Abstract

Harmful algal blooms (HABs) are extreme biological events representing a major issue in marine, brackish, and freshwater systems worldwide. Their proliferation is certainly a problem from both ecological and socioeconomic contexts, as harmful algae can affect human health and activities, the marine ecosystem functioning, and the economy of coastal areas. Once HABs establish, valuable and environmentally friendly control actions are needed to reduce their negative impacts. In this study, the influence exerted by the filter-feeding activity of the two sabellid polychaetes Branchiomma luctuosum (Grube) and Sabella spallanzanii (Gmelin) on a harmful dinoflagellate was investigated. Clearance rates (C) and retention efficiencies were estimated by employing the microalga Amphidinium carterae Hulburt. The Cmax was 1.15 ± 0.204 L h−1 g−1 DW for B. luctuosum and 0.936 ± 0.151 L h−1 g−1 DW for S. spallanzanii. The retention efficiency was 72% for B. luctuosum and 68% for S. spallanzanii. Maximum retention was recorded after 30 min for both species. The obtained results contribute to the knowledge of the two polychaetes’ filtration activity and to characterize the filtration process on harmful microalgae in light of the protection of water resources and human health. Both species, indeed, were extremely efficient in removing A. carterae from seawater, thus suggesting their employment as a new tool in mitigation technologies for the control of harmful algae in marine environments, as well as in the aquaculture facilities where HABs are one of the most critical threats.

Microalgae as a Promising Candidate for Mitigating Climate Change and Biodiversity Loss

“…This integrated approach not only addresses wastewater management but also presents an opportunity for resource recovery and the production of valuable products. The utilization of microalgae in wastewater treatment holds great promise in advancing sustainable practices and contributing to the circular economy [7]. Furthermore, microalgae contribute to the production of eco-friendly energy sources, offering a renewable and sustainable alternative to fossil fuels.…”

Microalgae: A Promising Future

“…Another ecological paper reported in this Special Issue focused on the bioremediation of the microalgal species that are considered “harmful” for their ability to produce toxins that negatively impact human health, and to induce blooms with detrimental effects on aquatic ecosystems, fisheries, aquaculture, and tourism [ 10 ]. As control actions are urgently needed to suppress harmful algal blooms, Stabili and co-authors [ 11 ] demonstrated the high filter-feeding capacity of two sabellid polychaetes, Branchiomma luctuosum and Sabella spallanzanii, on a harmful microalga (the dinoflagellate Amphidinium carterae ). Even if preliminary, these results could represent a sustainable and environmentally friendly method for the restoration of the aquatic ecosystems and a very advantageous tool for the management of the aquaculture plans.…”