Big Island, Small Abalone

posted by Sarah Curry on 13 February 2015

I love visiting fish farms, especially sustainable fish farms, so I was excited to check out Big Island Abalone on a recent trip to the Big Island of Hawaii. However, unless you’re an adventurous sushi eater or live on the West Coast, you may not have seen them around too much… we Americans tend to stick to what we know and like – tuna, salmon and shrimp! But since I am on a quest to expand the diversity of seafood in my diet, it was great to learn about abalone at the largest farm of it’s kind in the U.S.

Biosecurity sign

Abalone are molluscs and have one shell, and one big muscle or ‘foot’ that makes up the entirety of the fleshy part of their body beneath the shell, and it’s what they use to cling to rocky coastlines around the world. They are considered a delicacy on par with the likes of shark fin soup in some Asian countries, and some Californians go crazy trying to pry them out of rocky crevices. Abalone come in a range of sizes, the biggest being the red abalone in California that can grow up to almost a foot, but the abalone being grown at Big Island are smaller abalone, Ezo awabi, that are native to Northern Japan.

The 10-acre farm is just south of the Kona Airport in an area called the Hawaiian Ocean Science Technology Park (HOST). This area is home to several aquaculture companies and research facilities that take advantage of super deep, cold, clean ocean water that’s piped up and made available for the farms. Big Island Abalone mixes water from 3,000 feet deep and 150 feet to reach 60 to 65 degrees fahrenheit, the optimal growth temperature for the abalone.

How Does the Farm Work?


There are up to five million abalone on farm at any given time. Once a month the farm’s hatchery has a spawning, producing about 250,000 baby abalone.  The babies form a shell after about a week and from there enter into the first of five growth cycles.

Every couple of days the abalone are fed either dried red kelp, sea lettuce (a type of algae), or fish byproduct depending on what stage of growth they’re in. They grow and harvest six to ten tons of sea lettuce each week on site and the massive raceways that grow the algae take up a third of the farm.

The tanks the abalone live in are cleaned regularly by one of the farm’s 30 employees, but in a recent effort to clean the tanks more biologically, the company has added sea cucumbers and is waiting to see how and if this affects growth. When ready to harvest, the abalone are graded (divided up depending on their size), and either shucked or shipped live. The farm’s primary market is Japan, and they can get live abalone there in just 15 to 20 hours post harvest.  Right now the company harvests about 100 tons of abalone, but with hopes to work up to 120 tons.  Once the abalone are harvested, the water goes into a settling pond before being released back into the ocean. Our tour guide Frank assured us that even if any farmed abalone where to make it back into the ocean (they’re not native to Hawaii, remember?), they wouldn’t be able to survive, since the ocean temperature is too warm for them.


Eat ’em if you’ve Got ’em.

At the end of the tour we got to sample some that had been grilled ever so lightly in their shell, with no added seasoning. The result was a slightly chewy, but delicious and delicate morsel. It was good and kind of reminded me of calamari, so I ended up buying some at $19/pound to take home with me. My cousin and I successfully shucked them and removed the gonads, etc. before sautéing them ever so gently. Unlike the California’s red abalone, these don’t have to be pounded down to make them yummy. We cooked ours in butter and garlic, so even the skeptics in the room gave them a try.

Abalone are shellfish, and here at Fish Navy, we recommend consuming domestic shellfish as a sustainable seafood choice. Why? Shellfish are either filter feeds (oysters, clams, etc.) or herbivores, like the abalone. Having a sustainable food source is a major factor in raising any type of critter, especially seafood. See Seafood Watch’s guides for more information on different types of abalone farms around the world (1,2).  One more crazy cool thing — they can swivel their shells around almost 360 degrees! See it here.

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