Scientists first caught on to the strange event when they found thousands of purple sea urchins and other organisms dead in their laboratory tanks.

Northern sea nettle jellyfish die-off

7-29-14 Crab larvae wash ashore - Port Graham, Alaska, USA

7-26-13 Tadpole shrimp at swimming hole

7-3-12 Barnacle decline - McDonald Spit, Alaska, USA

Of all of the aquatic animals that could be collected in a gillnet on the Kenai River, crawfish are some of the least likely. Why? Because they do not naturally occur in the Kenai River or any other river in Alaska. Unfortunately, crawfish have been collected from the lower Kenai River twice in the last four years, and both times they were leftovers from someone’s dinner.