On the other hand, a species such as Chinook, which prefer to stay deep could use a 10m deep cage. Our observations inside gravity cages suggests Chinooks will be highly stressed in gravity cages because of the oscillating bottom. Many other species of fish are bottom dwellers and they will not do well in gravity cages. Cage shape best be selected based upon current cycles. In very low currents circular or hexagonal cages will fit in with turbo swimming patterns, whereas the corners in square, rectangular, and hexagonal cages provide wake shelter for fish constantly exposed to high currents.
Toxic blooms are a fact of life.
However we view the most recent event in Rich Passage, it did provide us with some insights into this phenomena. During this bloom we had divers in the water. They observed that there was a definite tendency for the plankton to orient toward the surface. Below 2 meter the water clarity was significantly better. The common thinking has been that the water mixes so thoroughly in Rich Passage that the bloom extends to full depth.