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

Artificial reef projects raise environmental questions - The Washington Post

A recent article in the Washington Post looks at the potential environmental concerns surrounding the sinking of decommissioned ships for artificial reefs. Among the issues which scientists are studying is the impact of overfishing as anglers gather at artificial reef sites and the accumulation of toxic chemicals, including PCB's, in the bodies of fish who feed off the reef.

Artificial reef projects raise environmental questions - The Washington Post

Artificial reef plan criticized by non-profit

 Next spring’s sinking of the USS Arthur W. Radford will pollute the ocean with toxic waste, cost Americans jobs and hurt marine life by attracting fish to one area where they will be over-harvested, according to a report by the Basel Action Network, a national nonprofit group that focuses on environmental and trade issues.

read more.... 

Artificial reefs not shown to increase regional fish production

An academic research concludes that despite their popularity

"...reef construction may have potentially deleterious effects on reef fish populations including (1) increased fishing effort and catch rates (2) boosting the potential for overexploitation of stocks by increasing access to previously unexploited stock segments and, (3) increasing the probability of overexploitation by concentrating previously exploited segments of the stock..."

read more

Artificial reefs & the red snapper ban

Creation of more habitat is suggested as a solution to declining red snapper population. But will it actually make the problem worse?

A point of contention among scientists, though, is whether reefs are beneficial for the environment. Some studies say reefs can provide spots for fish nurseries and lead to increased populations, while other studies show artificial reefs merely draw fish from a large region to a focal point for fisherman to pluck them out of the water -- like fish in a barrel, only underwater -- exacerbating overfishing.

read more here:
http://www.news-journalonline.com/news/outdoors/fishing/2010/06/28/ramping-up-reefs.html

Artificial reefs creating 'fish bowls'

Politician in Australia question the expansion and creation of artificial reefs and that the reefs benefit the fishers more than the fish.

''Most of the problems of fish stocks can be traced to inappropriate land use management, of estuaries, wetlands,'' he said. ''Why isn't the government spending money on areas that increase numbers of fish?''

Read more:
http://www.smh.com.au/nsw/government-chases-fishing-vote-with-the-great-yarra-reef-20100422-tg22.html

An article in Scientific American about using subway cars for artificial reefs

One question that was largely overlooked in the entire controversy was whether artificial reefs should be created at all. Many fishing groups supported the reef-building efforts, arguing that more reefs and therefore more habitat would lead to more reef fish, but that may not be the case. "It's obviously beneficial to the person who has a boat that makes money renting space on the boat to catch fish. And it's of benefit to the person that has a private boat and wants to catch fish," Bennett says. "The question is whether it's good for the fish, and I don't think we know the answer."

Read the entire article here:
http://www.scientificamerican.com/article.cfm?id=the-submerged-subway-reef

Understanding the Ecology of Artificial Reefs

A scientist in Florida discusses the complex issues surrounding artificial reefs including how fish populations are altered by their presence.

When we build a reef, we’re altering the availability
of the structure fish need in proximity to their foraging
grounds. So yes, they’re drawn to it, and there are rea-
sonable studies to suggest that in general, artificial reefs
hold initially higher densities of fish than natural reefs.
However, there is not necessarily the same biodiversity
or the same community composition because the reef
structures, by design, are different.

Read the entire article (in PDF form)
http://www.flseagrant.org/images/PDFs/sgeb_65_web%20optimized.pdf

Do artificial reefs work?

An interesting article out of Australia examining whether artificial reefs are an effective method of encouraging and protecting fish stock.

"The concept for constructing artificial reefs as a means of enhancing recreational fisheries is now considered questionable by fisheries managers if we are to maintain fish stocks at sustainable levels."

Read the entire article here:
http://www.pir.sa.gov.au/fisheries/recreational_fishing/artificial_reefs/do_artificial_reefs_work