Experimental evaluation of vinegar (acetic acid) for control of invasive corals (Tubastraea spp.) and a review of knowledge for other aquatic pests

Abstract

Vinegar/acetic acid (V/AA) has been used to control unwanted marine and freshwater species. As a naturally occurring, available and ubiquitous substance most countries’ legislations do not consider V/AA as harmful to the environment. We investigated the toxicity of household vinegar for the invasive corals Tubastraea coccinea and T. tagusensis (Dendrophylliidae), using injection (1, 2 or 4 of 10, 20 or 40 ml of vinegar) and immersion (full and half concentration; periods of 15, 30, 45, 60 or 120 min) treatments. For Tubastraea spp., immersion treatment always resulted in the death of the corals. In contrast, the lethality of injected vinegar depended on the number and volume of injections per coral colony; partially damaged colonies may be able to recover after vinegar injection. We also carried out a critical review and analysis regarding the use of V/AA in other aquatic species. V/AA has been tested and used as a biocide from virus and bacteria to fish; as for Tubastraea spp., three quarters of studies investigated the positive effects of V/AA as a biocide, the rest negative collateral effects on non-target species. We conclude that V/AA is an effective agent for killing Tubastraea spp. and most other aquatic organisms, can be applied using different methods and in different environments for controlling: (1) invasive or outbreak species; and (2) biofouling by native or invasive species on aquaculture systems and vectors. V/AA may be used applied pre-border to shipping vectors potentially transporting non-indigenous marine biofouling species such as Tubastraea spp.