Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtainthe best experience, we recommend you use a more up to date browser (or turn off compatibility mode inInternet Explorer). In the meantime, to ensure continued support, we are displaying the site without stylesand JavaScript.AdvertisementYou have full access to this article via your institution.Hello Nature readers, would you like to get this Briefing in your inbox free every day? Forty metres off the Italian coast, herbs, vegetables and flowers grow in six vinyl biospheres below the sea...…Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtainthe best experience, we recommend you use a more up to date browser (or turn off compatibility mode inInternet Explorer). In the meantime, to ensure continued support, we are displaying the site without stylesand JavaScript.AdvertisementYou have full access to this article via your institution.Hello Nature readers, would you like to get this Briefing in your inbox free every day? Forty metres off the Italian coast, herbs, vegetables and flowers grow in six vinyl biospheres below the sea...WW…