Dr. Dayton asked me to post the following statement from him back out to you all, in response to those several emails.

A couple pieces of context:
SAT = Science Advisory Team (for the California MLPA)
Ed Parnell (PhD) is a researcher in Dr. Dayton’s group at SIO

About Paul Dayton:  http://sio.ucsd.edu/Profile/?who=pdayton

PLEASE NOTE that he is only addressing the issue of whether artificial reefs such as the Yukon are killing zones and is not addressing the larger issue of the role of such sites in the California MLPA or in MPAs in general.

===== STATEMENT FROM DR. DAYTON =====

First, I am on the SAT for the MLPA and my understanding is that it is not appropriate for me to be involved in any discussions about specific MLPA issues, but some of you have already mentioned my two decades struggle to protect some habitats for future people to enjoy and learn from natural habitats.  I have also long advocated protecting examples of the best habitat and when possible not restrict the most intensive use.

But just for the record regarding artificial reefs and sunken ships, I can not recall writing a paper calling them killing zones, but I have discussed that term and in the beginning I did worry that they attracted fish that were otherwise rare where they were much more vulnerable to being killed.

However, the San Diego Ocean Foundation asked Ed Parnell to help them study that issue with what was really an excellent program on the Yukon.  There were a lot of divers and a huge amount of effort and Ed did a terrific job analyzing the data and the very brief take home message is that almost all of the fish that were around the Yukon had settled on the ship as larvae.  So if we think of the ship as a sink for larvae it seems unlikely that those larvae limit the populations on natural habitats.  Hence the ship attracts larvae at little cost to their natural populations.  Thus simplistically we can consider the ship as a means of enhancing those populations and even if every one of the fish that settled on the ship as larvae are killed, it is still a virtual wash in the big natural picture.  And of course the fishermen do not kill all of the fish, so the ship does enhance the fish populations which is a good thing to most people.

Second, the ship is covered with all sorts of really spectacular invertebrates and in my mind thus serves as a great educational value to divers interested in invertebrates.  I can not think of any down side to this and I consider it a huge positive value.  I just wish more people could be interested in such fascinating marine animals and make an effort to learn more about the natural history of these species.  And the ship vastly enhances the opportunity for those who do care to get out and enjoy some really interesting animals.  To this I plug the wonderful educational outreach efforts by the San Diego Ocean Foundation.  This group really makes a huge effort to expose the public to nature and I can not over-emphasize how very important that is.  And again, the Yukon is a wonderful asset to this outreach work.

The only potentially negative concern that I can not address is the hypothesis that the ship is leaking toxic material such as PCBs.  This could be tested by catching flat fish that live near the ship and would be expected to have concentrated toxins if they exist.  To my knowledge this has not been done because the analyses are expensive.

My personal, and I repeat it is very personal to me, view right now is that the Yukon offers a large positive role within these concerns. I was already persuaded of this at the last Dive Council meeting I talked to at Scripps and I did explicitly mention “killing zones” at that talk but then explained Ed Parnell’s excellent analysis and reported that I now supported sinking ships (within reason) so long as they were cleaned as well as the Yukon.  I emphasize again that it is really important to look for toxins in fish associated with the Yukon.  If there are a lot of toxins I would reconsider my support, but I do not now consider the ships to be killing zones as they cause a lot more larval settlement of larvae that would suffer mortality in the plankton I suspect.

===== END OF STATEMENT =====