Well Al's older than dirt, which makes him geriatric by any definition. Therefore, the sashimi grade of tuna that Al eats, is the geriatric version.
Some of the richest tuna fishing grounds in the world are off the Galapagos Islands. It's also the furthest north penguins are found in large colonies. Both are due to the cold waters of the Humboldt Current which peter out in the region of the Galapagos. Fishermen in the Galapagos are said to have been using trained penguins for generations to dive into vast schools of tuna, clamping down the fish, and swimming back to the boat where the birds regurgitate their catch to their owners, as they do with their chicks in the wild. The bird then goes back in water and after more tuna.
In the late 60's with mercury becoming more prevalent in tuna caught in the waters off Japan, the Japanese fishing interests had to look for other sources for the booming sushi trade, which demanded a high grade product. They headed to the Galapagos. After some conflict with Ecuadoran authorities the Japanese agreed to buy all of their tuna from the Ecuadorans themselves. The Ecuadorans kept their traditional Galapagos tuna fishery safe, and found a huge market in Japan for their high quality tuna with it's very distinctive taste, texture, and smell.
My guess is, and this only a guess, that sashimi, which is considered very high quality, would have to meet the Japanese standards to meet the demands of foodies here who demand authenticity. That means it very likely goes straight from the penguins gullet and into your stores.
I hope Al doesn't see this before he's had a chance to take his afternoon meds. If he starts yelling, "Soylent Green is people!", give me a heads up? It's the Fansomian distress cry. I'll send Dr. Zaius over with the wagon to pick him up.