‘Shipping is really bad news for cetaceans in the North Sea,’ Young Robbie said, with great authority. ‘We don’t know how many dolphins and whales we lose to ship-strike every year, because if they get hit by one of those massive container carriers, the ship doesn’t even notice, and then the body floats away to the bottom of the sea.’

‘That’s horrible,’ Anna said, watching as he rolled the pastry with endearing diligence. ‘Those poor creatures.’

‘Yeah,’ Robbie agreed. ‘Then there’s all the invasive species that come in with the ballast water. Container ships have these compartments in their hulls that scoop up water to balance their weight. They hold thousands of gallons. If they suck up a load of seawater near Japan, say, and then they come all the way over here to the Northern Hemisphere and unload, they have to dump all of that water – and whatever’s in it – here. And with climate change our water is warmer, and species that wouldn’t have been able to survive here before can now, and they’re breeding, which is bad for the local ecosystem as it disrupts the food chain. That’s how we’ve ended up with colonies of Japanese skeleton shrimp and the leathery sea squirt.’

‘The what?’ Anna laughed.

‘The leathery sea squirt.’

‘You made that name up!’

‘I didn’t!’ Robbie said, laughing too. ‘It’s a real thing! It comes from Asia, and now it’s here. Look it up.’

‘I will,’ she assured him, handing him the pastry cutter. He bent over the table, frowning as he concentrated on pressing out the fluted circles. He’s only ten, she thought. Eleven years ago he didn’t exist, and yet here he is now, helping me with pastry and telling me things I didn’t know.

‘Fishing can cause problems too,’ the boy said. ‘If a net gets lost, it stays around for years. Fish can get stuck in it, and then dolphins are attracted to the food source and can get stuck too. Then they suffocate, it’s horrible.’ He stopped what he was doing and looked at her with serious eyes. ‘That’s why you should only ever serve sustainably caught fish on your bench. There are labels you can look for.’

‘Noted,’ Anna said. ‘You said something about nets the first time I met you. Remember, when you I gave you the sea purslane to try?’

‘Oh yeah,’ said the boy. ‘Ghost nets get caught there all the time, especially after a storm.’ He pushed the cutter into the last patch of pastry and leaned back. ‘Is that all right?’

‘Perfect. Okay, now to put them in the cases.’ She handed him the tart tray.