Ideally, the NYSDEC’s regulations ought to be re-written in order to provide them disease-specific and site- specific regulatory authority. The “one size fits all” nature of the present regulations ignores the distinct epidemiologic differences of the listed diseases. And while containment is a laudable goal, it may be realistically impossible while neighboring and regional States are more ‘tolerant’ than New York about IPNV. It should be noted that IPN has become so widespread internationally that it is no longer listed as a disease reportable to the O.I.E (the world organization for animal health). It could also be noted that no animal or bird has yet been found which can recognize State borders or read a sign. Statistically, it is inevitable that more waters in NY will ‘get’ IPNV. All NYSDEC can hope to achieve is to delay its arrival as long as possible.
In the case of the CRSPP, the hatchery could have been permitted to continue raising a quite limited number of trout for downstream stocking only, while maintaining the upstream stocking ban. This may have permitted a gradual elution of the upstream viral reservoir while maintaining both its educational and productive character. Along with a disinfection regime for visiting anglers’ footwear, revenue could have been preserved while allowing time and budgeting for a more definitive approach. Judging from the 26 years in which the virus could have been, but was not explanted elsewhere, we see no reason why this approach could not have been successful.
Unfortunately, we are where we are. A complete re-construction of the hatchery to a pumped-water facility is financially out of the question, historically inappropriate, and probably incompatible with the hydrology of the river. So, what measures could be expeditiously undertaken? We would propose the following:
First: With the understanding that no fish have been stocked upstream since early 2007, begin an immediate water- surveillance program to measure viral concentrations over a period of a year.
This would entail the collection of at least two 5-liter aliquots of water from both the “feedwater canal” and the “deepwater pond” monthly and measuring the virus contained therein in terms of the standard of “pfu/l”, or “plaque-forming units per liter”. The months of October through April are of particular importance, insofar as rearing fry are concerned. In addition, at least one test should be performed on the well-head water available to the hatch-house. These sites represent the “final common pathway” of water for the hatch house and raceways.
Any results above 100 pfu/l probably preclude the use of the hatchery for stocking purposes, but not necessarily for strictly educational/demonstrative purposes (with the destruction & disposal of fish testing IPNV +ve.)
Results between zero and 100 pfu/l would suggest that sufficient elution of virus has occurred to make resumption of trout production feasible.
This surveillance could be done for an estimated cost of $ 12,000 to $ 13,000 . Second: Utilize the surveillance year to begin re-constructing the existing raceways. This would entail the placement of tile drains for the groundwater seeps, and either manufacturing all-concrete raceways or installing impervious plastic liners. This would be complemented by the manufacture & installation of effective sluice-gates.
Raceway re-construction would permit the effective de-watering, and disinfection in the event of a persistent or new disease occurrence.
Third: Apply to the USDA for an investigational permit allowing CRSPP to obtain the Schering-Plough food- additive vaccine which is used in commercial salmon-farming operations outside the U.S. The company maintains this product is 85% effective against IPNV.
As an indirect test of water quality, we propose obtaining certified disease-free rainbow trout eggs, rearing them in the hatch house using whichever potential water-supply has tested lowest for IPN concentrations, and begin feeding the fry with vaccine-treated food when they reach the “swim up” stage. Upon transference to the “nursery”, which is presently fed only by “canal” water, the administration of vaccine-treated food should be continued.
After transfer to the regular raceways is possible, the fry should be divided into two groups. One half of the fish should continue to receive the treated food, and one half should not. The fish should be held in two non- contiguous raceways, so that their water supplies are “in parallel”.