Artificial reefs: the effects are obvious but are they beneficial?

An article by Sara Bennington in the Blue Planet Magazine, Summer 2003 notes that while it may seem obvious that artificial reefs are good for fish, the truth may be a little more complicated.

"...Swarming fish at one site doesn't automatically equal a healthy ecosystem. "If you draw fish populations away from their natural habitat, then you have to ask if that is
having an effect on an adjacent population." 

"The concentrating effect of an artificial reef can
make it easier for fishermen to catch fish and lead to overfishing. In
addition to exposing them to human predators, these reefs can also
attract ocean predators that prey on these aggregations of smaller
fish that wouldn't be gathered if the artificial reefs weren't there."

Artificial reefs can also be detrimental to the existing habitat.

“To some people, it appears that a sandy ocean bottom is a wasteland with no value, so a reef would create a wonderful habitat,” Powell says. What people aren’t taking into account is that the sandy bottom is a natural habitat supporting ocean life. “Many artificial reefs are being put in place with little thought of how they affect the habitat that was originally there.”

Sara Bennington, Blue Planet Magazine, Summer 2003