First you hear it.
Like river rapids rushing over rocks, a frothing, hissing, bubbling sound that erupts out of nowhere. But there is no river, because you’re out at sea, rocking over the swells. There should be nothing but the gentle lap of waves against the boat.
And then you see it. White water. The sea is boiling, churning, alive.
And above this, a pulsing cloud of seabirds. Spinning in all directions, a flock of thousands spiralling in on itself and plunging into the sea.
This is a work-up. This is a shoal of fish feeding frantically on krill, and seabirds cueing in on this to get their own helping. It’s a chaos of wings and water.
The birds are following the fish, because the fish are following the krill. It’s the krill that everyone is after, a rich, energy-dense resource. With the spring blooms of phytoplankton, the Hauraki Gulf becomes a soup of algae, salps and krill that supports the higher levels of the food chain.
These work-ups aren’t stationary, and when you’re trying to film what’s happening underwater this can be a bit of a problem. We can’t see the currents of movement underneath, only the frenzy at the surface that erupts out of nowhere. One minute we’re on top of it – the next – it’s behind us and hundreds of meters away. All we can do is follow the birds. And hope that we’re lucky enough to be in the right position to capture the action.
To be in the middle of this storm of seabirds is nearly indescribable. You can smell them, the musky warm scent of petrels wafting over the sharp salt tang and the pungent whiff of algae. You can feel the brush of their wings as they pass by. The air is full of churring, squeaking, laughing calls. 
Fairy prions are filter-feeding, taking beakfulls of water and straining the krill out using the lamellae that line their bills. Fluttering shearwaters have a different strategy – plunging headfirst into the sea and flying just as effectively underwater as they do in the air to chase after prey. But we can’t see much of that from the surface – so that’s where the drop-cam comes in, a floating pole fitted with GoPro cameras facing in all directions to capture the underwater action.
When we’re lucky enough to get the drop-cam in the right place, the results can be spectacular. There’s just as much happening below the waves, which you can see here.
