Maine's popular spring wild edible is in season. Fiddleheads can be found along rivers and in other marshy areas around the state. A flavorful green, food safety experts warn of health risks associated with eating improperly cleaned and cooked fiddleheads. Credit: Julia Bayly / BDN

Foraging fiddleheads is a longtime tradition for Mainers. The tender croziers are a New England delicacy, with their unique, bright flavor and asparagus-like consistency. But could they become endangered with overharvesting?

Results of a four-year study conducted by a University of Maine Cooperative Extension expert shows that overzealous foraging of fiddleheads can cause significant decline or even destruction of their populations over time. David Fuller, the study’s author and University of Maine Extension agricultural and non timber forest products professional, analyzed how varying degrees of fiddlehead harvesting affect frond production and mortality. His findings were published in the Journal of the National Association of County Agricultural Agents.

The study focused on 30 ostrich ferns, each producing a minimum of four fiddleheads per crown, growing under mature sugar maples in a naturalized stand in Franklin County. Once every spring between 2006 and 2008, Fuller collected all of the fiddleheads from one group of ferns, half from another group and none from the third.

The fern crowns with all the fiddleheads removed in a single harvest suffered significant decline in growth in the subsequent years, and in some cases were killed outright. By the third consecutive year of harvesting, Fuller observed that these ferns exhibited a drop in mean fiddlehead yield per crown from 5.1 to 1.4, as well as mortality in 50 percent of the crowns.

The plants in which he harvested half of their fiddleheads exhibited a decrease in the mean number of fiddleheads from 6 to under 5 fiddleheads per crown in the third year. The group of ferns Fuller left unharvested produced the same average number of fiddleheads every year.

“These findings suggest that fewer than half of the fiddleheads from a given plant could be harvested and be sustainable with no follow-up harvest that year,” Fuller said. “Plants whose fiddleheads have already been harvested by other harvesters that spring should be left alone.”

Responsible foragers have long discouraged overharvesting in order to maintain populations year to year. Now, for fiddleheads at least, they have the science to back their ethics.