A new study warns that Marine Protected Areas (MPAs) may not be all they first appear to be.
The study by Tundi Agardy, an environmental consultant based in Colrain, Massachusetts, warns that too many people put blind faith in MPAs without first looking at the science behind where they should actually go.
At the moment there are more than 5,000 of these sanctuaries where fishing is either banned or limited to protect biodiversity. Sizes ranges from less than 10,000 square metres through to the Phoenix Islands area which measures a massive 400,000 square kilometres.
However, three has been very little assessment into how these MPAs might best be placed.
Agardy’s study highlights five key areas where MPAs might actually do the opposite of what they set out to do: some are too small to actually be effective; they may simply drive fishing into other areas; the fact that an MPA is there gives the impression that the area is being protected when in fact nothing is actually being done; many are poorly planned or managed; if there is environmental degradation of waters just outside the protected area then all of the sanctuaries will fail.
Agardy is quoted: "I'd venture a guess that a majority of the world's several thousand MPAs have one flaw or another relating to the five categories we describe."
A case which demonstrates her point is that of the MPA in the Gulf of California created to protect the small porpoise vaquita (Phocoena sinus), which actually missed a sizeable proportion of the species' core range. The animal's numbers have continued to decline and it is now the most endangered marine mammal in the world.
Frederic Vandeperre, a marine biologist at the University of the Azores in Horta wholast month published a review of several southern European MPAs agrees:
"We still need a lot of knowledge to really understand how MPAs work exactly. We should maybe create MPAs with different structures; different designs in a controlled way, to be really like an experiment so we can figure out which elements are crucial."
For more information see: Agardy, T., Notarbartolo di Sciara, G. & Christie, P. Mar. Policy 35, 226-232 (2011)