Shares in US land-based salmon producer AquaBounty have fallen more than 20 percent from Monday's high of $4.29 (€4.05) following the company's shareholders approving a reverse stock split aimed at avoiding a delisting from the Nasdaq index.

In September, AquaBounty called on its shareholders to consent to the stock split, warning a potential delisting would inhibit the company's ability to raise additional capital and potentially threaten its future.

On Oct.