So let's follow the energy flow in the kelp forest and see just what might be a stake here.
KELP FOREST ENERGY FLOW (PACIFIC COAST N. AMERICA):
(Energy flows from 1 to 7)
1. SUNLIGHT (AND NUTRIENTS)
2. KELP and other Seaweeds (mostly large brown seaweeds)
3. KELP DETRITUS (small bits of dead kelp WITH BACTERIA)
4. DETRITIVORES (GAMMARID AMPHIPODS, ISOPODS, OTHER SMALL CRUSTACEANS)
5. 45 SPECIES of INSHORE AND MIGRATORY FISHES THAT FEED ON DETRITIVORES
6. FISH EATING FISHES, RIVER OTTERS, SEALS, SEA LIONS, DOLPHINS, PORPOISES,
BALEEN WHALES, VARIOUS SEA BIRDS, BALD EAGLES, OSPREY
7. KILLER WHALES (ORCA)
The key to the entire ecosystem is, of course, KELP. In the natural world of shallow water Pacific coast of N. America the major organism tasked with controlling the populations of kelp eating herbivores is the SEA OTTER.
NOTE: While other predators (Sea Stars, snails, crabs) also prey on the herbivores they have not demonstrated the ability to keep the herbivore populations in check to protect the kelp beds in the absence of the Sea Otter.
|Kelp eating Sea Urchins|
|Chiton - kelp eating|
|Kelp eating limpet|
|Gunnel - eats amphipods|
|Sculpin - eats amphipods|
|Clingfish - eats amphipods|
|Flounder - eats amphipods|
|Juv. Salmon - eats amphipods|
|River Otter - eats fish|
|Great Blue Heron|
|CA Sea Lions|