Spring is a time of year full of religious significance. There are many different traditions to accompany those holidays. You might think that I would write about seafood and the significance of fish in these spring holidays. But I actually wanted to write about what people wore — or more like what people wore many years ago that took its significance from the sea.

If you asked your average person what color signifies royalty, they would say the color purple. The origins of this color, however, are less obvious. It turns out that one of the first purple dyes came from a humble snail simply trying to defend itself — one that happens to live in Maine. And that purple wasn’t just used to signify royalty but was also used to color the robes of priests and the pages of religious texts starting back in the 6th century in the Roman era.

One of the reasons that purple was so valued was because it was hard to come by. The purple dye that comes from a whelk comes from a gland called the hypobranchial gland and is composed of bromine, along with other components. In order to get the dye out of a snail, you either have to be really good at “scaring” it, a process called “milking,” or you smash the snails. This has resulted in shell piles, somewhat akin to middens we have in New England, where people smashed the snails for their dye. Regardless of the method used to harvest the dye, it takes a lot of snails to dye a piece of cloth — hence its high value as a color and the reason it was used to signify wealth and power.

It’s always interesting to think back to who first figured out that snails produce purple dye and how they figured out how to use it. For one, when the dye is first released, it doesn’t look purple at all but is rather a milky color. But if you collect the dye or collect it onto a piece of cloth, it eventually turns purple. The beauty of doing this in the sea is that the salt and sun help to speed up the process and also to set the dye. I have yet to try this, as I’m not keen on killing snails for fun, but am tempted to try it on a small scale and then perhaps eat the snails afterwards.

The type of snails that produce this dye are called whelks. They are predatory snails that live in the intertidal and prey upon other shellfish including other snails. There are multiple species of whelks that produce this type of dye. The spiny murex Bolinus brandaris, the banded murex Hexaplex trunculus and the rock-shell Stramonita haemastoma are all Mediterranean species.

The snail that we have in Maine that produces a similar dye is the dogwhelk or dogwinkle (Nucella lapillus) and is also found on much of the coast of Europe.

Dogwhelks are the ones that drill tiny holes into the shells of their prey. You can tell a dogwhelk from a periwinkle by the tiny groove at the spire of its shell where its powerful drill-like radula comes out to drill these holes, then liquifying its prey with digestive juices it secretes out and funneling it back into its body through its siphon. This differentiates whelks from periwinkles, another small-ish sea snail species that lives in similar environments and locations but are herbivores that use their rough tongue-like radulas to scrape algae off the rocks. Periwinkles don’t have the same type of dye that whelks do.

Knowing the ancient process of procuring purple dyes gives me a much greater respect both for the color purple that is so easy to come by these days and also for whelks that I just thought were vicious predators but, it turns out, are also producers of a powerful and power-marking dye.

Susan Olcott is the director of operations at Maine Coast Fishermen’s Association.