I’m at love.fish’s new restaurant at The Streets of Barangaroo, and there’s a turban snail conch, covered in barnacles, sitting on the bar. It’s alive, but not for long. Within the hour it’ll be boiled, the flesh extracted and enveloped in fresh ravioli dough, the final result covered in a black-bean butter sauce.

The snail has just arrived via Greg Finn, a NSW diver who harvests everything by hand. “He's an amazing guy,” says Michelle Grand-Milkovic, co-owner of love.fish. “I literally call him [with an order], he goes out, catches what I need and then it arrives.”

If anything sums up what love.fish does, it’s this. Turban snails aren’t a common menu item for most restaurants. But the creature and the tale behind its appearance on the bar fits the love.fish ethos perfectly – local produce, sustainably sourced.

Since opening the first love.fish in Rozelle in 2010, with a menu of gurnard, latchet and Spanish mackerel (a little-used fish in Australia at the time), Michelle and her husband and co-owner, Michael Milkovic, have been leading a revolution in Sydney seafood. With their Rozelle operation now an institution, they’ve opened their second outlet at The Streets of Barangaroo. “We have always wanted to do this as sustainably as possible,” says Grand-Milkovic. “I want my kids to be able to have this choice of seafood when they're 40. Australia has amazing produce - how do we consume it in a way so that it’s available [in the future]?”

To balance fish stocks and combat unsustainable fishing practices – regional over-fishing and mega-trawlers being the chief culprits – love.fish champions the use of lesser-known fish, avoids any threatened or endangered species (a far less common practice than you’d imagine) and strictly uses only Australian and New Zealand produce.

It also sources directly from local fishermen, something reflected in how the produce is prepared. For example, the abalone at love.fish, which is handpicked by Finn, is made into a schnitzel at his suggestion. “We cook it the fisherman's way,” says Grand-Milkovic. “It's literally shuck, crumb, cook. It's super simple but amazing. It melts in your mouth.”

Finn also provides love.fish with a sustainable supply of live sea urchin. “Lots of small fast-growing species are quite sustainable,” says Grand-Milkovic. “The issue is how they're harvested. These urchins are harvested by hand so there's no by-catch (unwanted sea creatures, common in commercial fishing methods).” To make use of the product’s incredible freshness and flavour, love.fish serves it in a taramasalata with rye toast, radicchio and egg yolk, or live with just lemon, bread and salt.

Working so closely with providers like Finn makes love.fish’s ethical food-sourcing decisions easy when it comes to abalone, urchin and turban snails. But for other products it’s more complicated. “Sustainable seafood has to be one of the murkiest subjects,” says Grand-Milkovic. “You cannot get a definitive answer. Every fishery will tell you something different and every area has a different accreditation.”

Grand-Milkovic says for those looking to buy sustainable produce, there are a few rules you can follow when browsing the fish markets. “Always choose Australian or New Zealand [produce],” she says repeatedly. “You'll pay a premium, but it'll be worth it to buy seafood that's come from within the country. You can be assured stocks have been harvested on a level that's sustainable.”

The other key rule is to always ask questions. “Ask where it’s from,” says Grand-Milkovic. “Is it line caught? Was it farmed or wild caught? Some say fish farming is not sustainable, but there are some really smart eco-focussed operators.”

Finally, the restaurateur says, crucially, you need to care: “You need to be passionate and curious, as well as understand that you won't get it right every time.” She adds that perhaps there’s already an available service cutting out the need for such decision-making. “That's why you'd come to love.fish,” she says, “where it's as fresh and sustainable as possible. We've done all the hard work for you.”

This article is presented in partnership with The Streets of Barangaroo.