HomeMy WebLinkAboutCOM 0880.005 2008-2010Below is Dan Polhemus' response about Rene's statement regarding aquarium collectors under reporting and she
likes to quote him directly.
Begin forwarded message:
From: Dan.A.Polhemus®hawaii.gov
Date: December 23, 2009 8:25:16 AM HST
To: XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
Subject: Re: Your quote is being used is it accurate?
H i XXXX -
Thanks for the dialog. Let me see if I can address your questions.
First regarding underreported aquarium catch. Unfortunately there hasn't been a comprehensive study of
whether there is substantial underreporting in the aquarium fishery (or any other fishery). The numbers I've
cited in the past (2X -5X unreported catch) are based on two previous studies of the Hawai i aquarium fishery.
I have attached the reports for you. This is the best information that's available. Given human nature it
wouldn't be surprising that some level of underreporting occurs but there is no information anywhere to
support anything like the 10X figure which I've heard mentioned. Furthermore when we've compared the
number of animals caught, as reported by collectors on their fish catch reports, with the numbers purchased by
dealers there isn't any indication of gross underreporting by the collectors.
As far as aquarium related mortality in Hawaii goes here's a quote from a Cesar 2002 study "Mortality
rates of aquarium fish are low and have gone down considerably since the last survey in 1984. Currently,
mortality rates from collection to wholesaler are estimated at 0 to 1 percent. In the wholesalers tanks,
mortality rates range from close to 0% up to 2 %. During shipment, rates range from 0.75% to 2 %. This give a
current total of between 1% and 5 %, down from a range of 5% to 8% in the early 1980's (van Poolen and Obara,
1984; estimates of wholesalers and collectors, own study)."
I haven't seen any work to support the figure of 99% mortality rate within one year for captive
marinelife. For animals which have been collected using cyanide this may not be unrealistic and there is good
work on such chemical related mortality. The aquarium fishery in Hawaii does not use destructive chemicals.
The 2007 statistic cited indicating that 20,000 reef animals died while in the possession of collectors seems
to be based upon comparing what collectors report as being caught vs. what's sold. In 2007 this difference was
20,345 animals statewide. A closer examination of the catch report data reveals that of that total figure,
6,000 or so were miscellaneous shrimp, most likely opae ula, which were being harvested in fairly large
numbers around that time. We don't know why such large number of shrimp were caught and not sold. They
may have been used for fishing purposes or to feed aquarium fish. They're pretty hardy animals so this
difference may not represent collector related mortality but a redirected use.
Another interesting component of the reporting that year was a single monthly report in March 2007 that
indicated a catch of 8,897 yellow tangs by a Big Island collector. Of these only 850 were reported sold. This
seems to be an unrealistically high reported catch for a single collector in one month not to mention in March,
months before settlement of the young, more collectible, tangs occurs. We checked the actual report and there
was a data entry error. It should have been 897 caught (not 8,897). Thus the total FY 2007 difference
between #'s caught and sold is actually 12,345 of which almost half were miscellaneous shrimp. For FY 2009
we see that there was a difference of about 18,000 in the number reported caught and sold. 16,000 of these
mr.�
Co. No. o th o 0. C
Ref, To P F SCi
Rif. fate A 0 2 late
were opae ula. The difference in yellow tangs reported caught and sold was 2,233, which if it does represent
mortality, suggests a collector to dealer mortality of 0.8% - quite similar to what Cesar found.
It is a good thing for folks to scrutinize and ask questions about what's going on in our fisheries and on
our reefs. These are important to all of us. A realistic perspective does need to be maintained however. Let
me elaborate. On Maui in 2009 there were a total of 16,300 aquarium animals caught, representing 82
different species. Yellow tangs accounted for 69% while Kole was 7% of the catch. During that same year non-
aquarium commercial fishers captured (and killed) 319,491 reef fishes of 75 species. While yellow tangs
weren't caught to any degree there was considerable overlap in a number of the other species. To the
commercial food catch one can add another 480,000 reef fish taken by recreational /subsistence fishers
(extrapolated from 2006 NOAA Rec Fishing Survey data). So, in the grand scheme of things, the aquarium
take on Maui is literally a drop in the bucket, representing less than 2% of the total mortality of reef animals
that year. This serves to point out that undue focus and hyperbole about aquarium collecting and its impact on
the reefs is dangerously shortsighted and counterproductive. We need to think and act holistically.
Hope I didn't overwhelm you with numbers.
- Dan Polhemus
Dr. DAN A. POLHEMUS
Division of Aquatic Resources
State of Hawaii DLNR
1151 Punchbowl St.
Honolulu, HI 96813
Phone: (808) 587 -0100
e -mail: Dan.A.Polhemus @hawai i .gov