Otter (Lutrinae) Care Manual - Association of Zoos and Aquariums

PART 3: DISINFECTION
Association of Zoos and Aquariums 144
Otter (Lutrinae) Care Manual
Bromine: Bromine is unsuitable for outdoor usage as it is broken down very quickly by sunlight
Ozone-Chlorine comparison: The common perception is that ozone systems are more elaborate and
expensive than chlorine. In truth, both systems will require that water parameters be measured. If the
operator starts with more or less a blank slate, the level of sophistication required to safely and effectively
operate and maintain a properly designed chlorine disinfection system vs. the level of sophistication
required to safely and effectively operate a properly designed ozone disinfection system may just about
be equal.
Indeed, one could argue that the chlorine system operator needs a higher level of sophistication and
dedication and needs to work harder and be more attentive than if they had an ozone system. As we are
talking about otters, when comparing an ozone system to a chlorine system, the latter system is more
likely to harm the animals (or their human caretakers).
Ozone: If you have a well designed, installed and maintained system, the operator will keep the various
filters and probes clean. They might occasionally turn a few dials but other than that, operation consists
primarily of monitoring the system and recording data. Every year or so you should get a visit from an
ozone tech for the more serious maintenance issues depending on your system, but that is about it.
Advances in design now allow us to use much smaller dosages of ozone than in the past with the
resulting decrease in safety concerns.
The oxidation process with ozone occurs in the contact chamber away from the animals, and any
residual ozone is unlikely to be anywhere near as harmful, if at all, to the otters as chlorine residuals. The
by-products of ozonation can be dealt with.
Chlorine: In the United States, many municipalities add chlorine to their water, and readings from tap
water of 1ppm or higher are possible. For this reason, many aquariums run their city supplied water
through carbon filters prior to use. While otters generally show no adverse effects from these levels, it is
not known what the overall impact is to their health and the water repellency of their coats. For this
reason, the AZA Otter SSP recommends that otters should not be exposed to chlorine levels higher than
0.5ppm for prolonged periods, and ideally, chlorine should be kept at a non-detectable level. The addition
of sodium thiosulfate will neutralize any residual chlorine. The most efficient and effective way to do this is
to use an automated system (www.polarispool.com/products/details.asp?ID=34).
This would cost you about $5000.00 to buy and install. Because chlorine is most effective between
the pH of 7.2-7.8, such automated systems draw from sodium hypochlorite barrels and muriatic acid
barrels. Without an automated system, the pool will have to be tested daily and chemical adjustments
made manually. Even with the automatic controller, this system is inherently more labor intensive than an
ozone system.
The oxidation process with chlorine occurs in the water with the animals that are exposed directly to
the chemicals. Therefore an overdose of chlorine or muriatic acid would affect the animals. Increasingly,
evidence is mounting that chlorinated pools may cause health problems in humans
(www.swimming.about.com/od/allergyandasthma/a/cl_pool_problem_3).
Therefore all things being equal, one has to wonder how sensible and ethical it is to continue using
chlorine with otters. Chlorination produces carcinogenic byproducts know as Trihalomethanes (THM)
(www.epa.gov/enviro/html/icr/gloss_dbp). Sooner or later, this may become a regulatory issue and we
have no way of removing THM from the process.
In the end, the decision on the type of disinfection to use is an equation. Your particular institution
may have a set of circumstances (access to highly trained personnel and sophisticated water quality
measuring equipment, inexpensive sources of sodium hypochlorite and muriatic acid, lots of cheap labor,
etc.) that will sway the equation towards chlorine. And in cases where algae is out of control, chlorine may
be the most immediate and cost effective solution.
However, all things being equal, our experience has been that when you add up the total cost of
doing it correctly over a number of years, having an ozone disinfection system works out to be cheaper,
less dangerous, and far less labor intensive. Time is money.