Artificial Reefs: do they help or harm?

Here's some thoughts from recent articles about artificial reefs (emphasis mine):

Concern Lingers on Success of Artificial Reefs
Charles Q. Choi, LiveScience.com Yahoo News 27 Dec 07;
full report also on wildnews

The past 50 years saw artificial reefs built using anything from obsolete oil rigs and decommissioned warships to junk such as tires and washing machines. Not all have proven boons to the environment — some have proven ineffective or actually harmful.

"We've gotten smarter since then — we know what materials to use now to build artificial reefs," Perry said. "We don't want to just throw anything out there in the water — artificial reefs aren't just dump sites."

"You want to also make sure that artificial reefs are placed in a fairly stable environment and be outside of surf-pounding areas," Perry said. "You want to avoid them getting moved about by wave action."

However, "natural reefs are obviously still valuable," Perry said. "You can't just destroy a natural reef and put out an artificial reef as a replacement. Artificial reefs may help offset the growing worldwide loss of natural reefs a little bit, but they should not be the only answer."

Concerns do linger as to whether artificial reefs are good for the oceans.

"By concentrating fish all in one place and making them easier to catch, they may exacerbate issues of overfishing,"

Reefs in Peril: an interview with Dr. Nancy Knowlton
Katherine Cure, e-magazine.com Nov/Dec 07 Vol. XVIII, no. 6;
full report also on wildnews

What do you think about the restoration initiatives that are being tried with electricity or the implanting of new artificial reefs? Do you think we’re losing time with those experiments or do you think they might contribute to helping?

The one big issue with restoration is that there’s no point in doing anything about it, if you haven’t eliminated the original causes of coral reef decline. Because then the same things will happen with the restored reefs, as with the original reefs.

Restoration has its role, but in general, we need more attention to improving conditions. That means lowering fishing pressure, improving water quality and dealing with greenhouse gas emissions.

It’s more cost-effective than restoration initiatives, unless very specific conditions exist.

Dr. Nancy Knowlton is a coral reef scientist who studies their ecology and evolution, including the impact of climate change. The founding director of the Center for Marine Biodiversity and Conservation at the University of California, San Diego, she is also a professor at Scripps Institute of Oceanography. Her contributions have been crucial to the advancement of coral reef science.

Today, Knowlton holds the Sant Chair in Marine Science, recently awarded by the Smithsonian Institute’s National Museum of Natural History in Washington D.C. Occupying the museum’s first funded chair in marine sciences, Knowlton will provide leadership to the Smithsonian’s Ocean Initiative, an interdisciplinary move to foster greater public understanding of ocean issues.