The allure of tiny silversides

Summer is here – and with it the silversides. Divers and snorkellers rejoice when these tiny silver fish, each no more than an inch long, gather in their millions in the summer months, crowding into caves and tunnels.

The sheer number of fish and the way in which the vast shoals move as one, are a spectacular sight. It is made all the more spectacular because it’s a sight that is here today, gone tomorrow.

Nobody knows for sure where they come from, where they go to or what they are. Silverside is a generic term which covers a variety of silvery juvenile fish including sardines, anchovies and herring and when they appear here in their millions, there could be several species schooling together.

Origins unknown

It is not clear why or how they suddenly appear (maybe they have just grown to a visible size) but last week the silversides arrived in force, filling the swim-throughs and tunnels at Eden Rock and Devil’s Grotto, two dive sites which lie side by side and are easily accessible from shore in George Town.

They have been gathering in the caves and grottos of East End for around three weeks now. They mass together in tight swarms for protection, explains Chris Burrowswood, an instructor at Eden Rock Dive Centre, but ironically, these huge bait balls are also their undoing.

“They pack into such a tight ball that when a bigger fish starts circling them, they have nowhere to go,” he says.

During daylight hours, Chris explains, they gather in the tunnels for extra protection – not only are they not so visible (almost every other larger fish on the reef will prey on them) – but within the confines of these caves larger fish, such as tarpon, can’t get up the speed to attack effectively.

Tightly packed in

For divers, however, swimming into a cave that is packed so tightly with fish that one cannot see more than a few inches ahead, feels like literally being part of a wildlife documentary. As you swim forward through the thick cloud of fish, they move apart as if to let you pass, somehow always retaining their group formation.

The fish are packed so densely it can almost make you dizzy at first, as your eyes struggle to find one thing to focus on. But if you stop and turn around, you can form a clearing for yourself in the heart of the swarm. And then just watch and wait. It is a bit like to watching in an Imax 3D film.

Sooner or later, a large shape emerges from the shadows: as the normally slow, lumbering tarpon breaks through the wall of silversides into your clearing you are treated to a personal feeding show. Millions of tiny fish move in unison, visibly frustrating their less agile attacker, as they swirl and swarm around him, always just a few inches out of reach.

To be in the midst of such an abundance of marine life and to witness predator and prey playing out their roles is one of those events of nature that should not be missed.

It is not clear if any silversides survive the feeding frenzy and there is no predicting how long they will be around. Last year they arrived in two batches at Eden Rock, one in June, another in August. The year before they didn’t come at all. Who knows what will happen this year – but as long as they are around, they are certainly a sight to behold.