Science Magazine published a report on Cascading Effects of the Loss of Apex Predatory Sharks from a Coastal Ocean on March 30, 2007.
A summary of the same article on CBC News
I listened to an interview with the authors on the BBC. If I can recall the details of the interview accurately:
1. Shark fishing by man has reduced apex shark populations by 90 percent. (Editorial: So much for claims that shark fishing for sport has a neglible effect on populations.)
2. The massive decrease in apex shark populations has led to a 10-fold increase in the populations of apex shark prey populations such as skates, rays, etc.
3. The incease in skate and ray populations has decimated certain shellfish species such as scallops. One researcher noted that in previous studies passing skates and rays had no appreciable effect on local shellfish populations. But now the skate and ray populations are so large that shellfish are virtually eliminated in their entirety in areas where skates and rays feed.
The cause and effect were verified by placing closely-placed vertical stakes in the sea floor to prevent skates and rays from feeding in that area. The shellfish within the staked area were untouched whereas shellfish in the surrounding area were decimated.
3. Robert E. Hueter, director of shark research at Mote Marine Laboratory in Sarasota, Fla., said scientists have warned about the effects of shark depletion for years but there have been few studies to back them up. This report, he said, "demonstrates plausible links between the decline of sharks, the subsequent rise of their prey, and the resulting decline of those prey species' prey. You don't have to be a marine biologist to grasp this connection."
A summary of the same article on CBC News
I listened to an interview with the authors on the BBC. If I can recall the details of the interview accurately:
1. Shark fishing by man has reduced apex shark populations by 90 percent. (Editorial: So much for claims that shark fishing for sport has a neglible effect on populations.)
2. The massive decrease in apex shark populations has led to a 10-fold increase in the populations of apex shark prey populations such as skates, rays, etc.
3. The incease in skate and ray populations has decimated certain shellfish species such as scallops. One researcher noted that in previous studies passing skates and rays had no appreciable effect on local shellfish populations. But now the skate and ray populations are so large that shellfish are virtually eliminated in their entirety in areas where skates and rays feed.
The cause and effect were verified by placing closely-placed vertical stakes in the sea floor to prevent skates and rays from feeding in that area. The shellfish within the staked area were untouched whereas shellfish in the surrounding area were decimated.
3. Robert E. Hueter, director of shark research at Mote Marine Laboratory in Sarasota, Fla., said scientists have warned about the effects of shark depletion for years but there have been few studies to back them up. This report, he said, "demonstrates plausible links between the decline of sharks, the subsequent rise of their prey, and the resulting decline of those prey species' prey. You don't have to be a marine biologist to grasp this connection."
I don't care for fishy tasting fish. The lighter and whiter the better.
