Uptake of Paralytic Shellfish Toxins by Blacklip Abalone (Haliotis rubra rubra Leach) from direct exposure to Alexandrium catenella microalgal cells and toxic aquaculture feed

Andreas Seger; Gustaaf Hallegraeff; David A J Stone; Matthew S Bansemer; D Tim Harwood; Alison Turnbull

doi:10.1016/j.hal.2020.101925

Uptake of Paralytic Shellfish Toxins by Blacklip Abalone (Haliotis rubra rubra Leach) from direct exposure to Alexandrium catenella microalgal cells and toxic aquaculture feed

Harmful Algae. 2020 Nov:99:101925. doi: 10.1016/j.hal.2020.101925. Epub 2020 Oct 27.

Authors

Andreas Seger¹, Gustaaf Hallegraeff², David A J Stone³, Matthew S Bansemer⁴, D Tim Harwood⁵, Alison Turnbull⁶

Affiliations

¹ South Australian Research and Development Institute (SARDI), Seafood Safety and Market Access, 2B Hartley Grove, Urrbrae, 5064, Australia; Institute for Marine and Antarctic Studies, University of Tasmania, 20 Castray Esplanade, Hobart, Tasmania, 7001, Australia. Electronic address: andreas.seger@utas.edu.au.
² Institute for Marine and Antarctic Studies, University of Tasmania, 20 Castray Esplanade, Hobart, Tasmania, 7001, Australia.
³ South Australian Research and Development Institute, Aquatic Sciences, 2 Hamra Avenue, West Beach, 5024, Australia.
⁴ South Australian Research and Development Institute, Aquatic Sciences, 2 Hamra Avenue, West Beach, 5024, Australia; Primary Industries and Regions South Australia, Fisheries and Aquaculture, 25 Grenfell Street, Adelaide, 5000, Australia.
⁵ Cawthron Institute, 98 Halifax Street, Nelson, 7010, New Zealand.
⁶ South Australian Research and Development Institute (SARDI), Seafood Safety and Market Access, 2B Hartley Grove, Urrbrae, 5064, Australia; Institute for Marine and Antarctic Studies, University of Tasmania, 20 Castray Esplanade, Hobart, Tasmania, 7001, Australia.

PMID: 33218447
DOI: 10.1016/j.hal.2020.101925

Abstract

The Tasmanian abalone fishery represents the largest wild abalone resource in the world, supplying close to 25% of the annual wild-caught global harvest. Prompted by the need to manage Paralytic Shellfish Toxin (PST) contamination of Blacklip Abalone (Haliotis rubra rubra) from east coast Tasmania, the uptake of toxins by this species is investigated in a land-based, controlled aquaculture setting. Abalone were exposed to either live Alexandrium catenella microalgal cultures or PST contaminated feed pellets during a 28 day exposure period and toxins quantified in viscera, foot muscle and epipodium tissues. PST profiles of abalone foot tissues were dominated by saxitoxin and neosaxitoxin, whilst viscera more closely resembled those of the toxin source (A. catenella cells rich in gonyautoxin 1&4 and 2&3 or feed pellets containing A. catenella extracts rich in these analogues). This indicates direct uptake of PST in the viscera via browsing/grazing on the pellet and /or sedimented microalgal cells. After exposure to A. catenella cell culture, PST concentrations in the foot (muscle + epipodium) were on average 8 times higher than in the viscera. Higher toxicity of foot tissue was caused by higher PST content of the epipodium (up to 1,085 µg STX.2HCl equiv. kg^-1), which despite its small contribution to total animal weight significantly added to the overall toxin burden. Higher PST levels in the abalone foot suggest that toxin monitoring programmes may not need to routinely analyse both foot and viscera, potentially allowing for a 50% reduction of analytical costs. This option is being further investigated with continuing field studies.

Keywords: Bioaccumulation; Biotoxin; Epipodium; Gastropod; PST profile.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Aquaculture
Dinoflagellida*
Microalgae*
Seafood
Shellfish / analysis