The Seaweed Harvesting Horses of Prince Edward Island

Irish moss is a cash crop that grows wild in the waters off Prince Edward Island, Canada. When storms uproot it and send it washing into the surf, farmers hook up horses to dredges and scoop it up. Brian Barth describes the process in Modern Farmer. He talked to 60-year old Joe Dorgan, a lifelong resident of the island:

I asked Dorgan what I thought was an obvious question: Why horses? When the tradition started on PEI in the 1930s, draft horses were still commonly used in agriculture, so it makes sense that their strength would be harnessed to pull heavy clumps of seaweed ashore. But surely a more efficient mechanized approach would have been devised by the time the industry hit its peak in the ’70ss. Dorgan’s answer wasn’t particularly scientific: “The horses don’t mind the water, and they’re good workers, and that’s just been the way it was,” he says. “Our ancestors done it that way and it’s still done that way today.”
I suspect that the problems associated with using motorized machinery in saltwater, like accelerated rust and corrosion, may have been a practical obstacle. But perhaps the industry was never big enough to warrant R&D investment anyways—a $6 million industry can hardly be called an industry.