As johnntj stated, the 90's were a uni heyday. Scallops were being depleted and and it gave the divers a new revenue source. Because urchin harvesting was a new business, it was unregulated and by the time the good ol' State of Maine got around to regulating it, they were already over harvested and the damage done. Uni lovers, close your eyes and imagine 5 gallon plastic buckest filled w/ fresh uni ready to get taken to Bangor and air freighted to Japan.
The question is why would you want to?!
I have eaten just about everything that swims, flies or walks at some point. but despite several tries I just can't understand the appeal of uni. it is far and away the most unpleasant thing i have ever eaten (fermented tofu a close second)
Regardless, I wish you well on your search.
Well, I used to dive for these things in the '90s - seven straight winters. I'd had 'em at sushi bars before I moved to Maine to dive for "Whore's Eggs" and thought they were better with a raw quail egg on top. Then I had a couple right out of the water and they were outstanding. I used to eat one from my first bag of the day for good luck. Since I was reasonably able to escape serious injury and cheat death a couple times I have to say that little regimen worked like a charm.
It's just too bad they are extremely perishable so no-one but uni harvesters get them in such pristine condition. There are arguments, however, that support their flavor after a certain time out of the water, processed and trayed. They get a gaminess that is appealing to most people, myself included - so long as it comes with a quail egg.
i've live Uni had at a few Sushi spots in town.
it's a great experience.
they will first snip the quills then open the bottom and remove the gonads. they line the shell (on top of the 'other' stuff) with shiso leaves and place the Plump, Yummy, Ocean Goodness on top.
the kick is that they serve the whole urchin (quills down) on a bed of rock salt and ice in a cocktail glass, the quills move and the salt/ice mix 'crunches' as you eat.
Very rarely found in any New England retail venue. You might be able to order it from Browne Trading in Portland Maine:
100g trays of fresh Maine urchin were for sale there a month ago for $18 each without shipping but the season is winding down, if not over until September.