Contaminants and Hatchery Fish (Q & A)
Q. Do hatchery-raised fish contain contaminants such as PCBs? If so, why?
A. Hatchery or farm-raised fish, like most food we eat, contain small amounts of contaminants such as PCBs. These contaminants are widely present, do not break down rapidly in nature, and are found throughout food chains.
Q. Has new information become available about PCBs and farm-raised trout or salmon?
A. Yes, a recent study reported on PCB concentrations in farm-reared salmon from a variety of locations in the world. The results showed low but differing levels of PCBs depending upon the species of fish tested and where the fish were raised. The results also showed that wild salmon contain PCBs, again in differing amounts.
Q. DEC raises lots of trout and salmon, what is known about PCB concentrations in those fish?
A. Samples of hatchery reared trout and salmon from DEC hatcheries were analyzed for PCBs several years ago, well in advance of the recently published study. The results showed that PCB concentrations were very low, usually less than the detection limit at our laboratory of 20 parts per billion. The current FDA tolerance level for PCBs in commercially caught and marketed fish is 2,000 parts per billion.
Q. What species and sizes of fish did DEC test?
A. DEC tested the species and sizes that are most commonly reared for stocking, and a few larger specimens that we retain for egg taking purposes. We tested brook trout, brown trout and rainbow trout that averaged 8-9 inches in length. We also tested 2-year-old brown trout, which are 12-14 inches in length. These are the species and sizes that are most commonly stocked and immediately available for legal harvest in waters managed with statewide angling regulations (ie. no minimum size limit for trout).
Q. What about larger fish?
A. DEC also tested Atlantic salmon broodstock, which averaged 20-22 inches long. The PCB concentrations in these fish ranged from less than 20 parts per billion to about 120 parts per billion.
Q. Why was there a difference in PCB levels between the smaller and larger fish?
A. In general, larger/older fish will accumulate more PCBs via food intake over time than smaller/younger fish because the larger/older fish eat more and so can be exposed to more contaminants. DEC's results showed that pattern.
Q. How do the contaminant levels from DEC's results compare to levels used to establish fish consumption advisories?
A. The PCB concentrations found in fish tested by DEC were lower than the thresholds used to establish highly restrictive consumption advisories. The concentrations found were consistent with the general statewide fish consumption advisory of no more than one meal per week of fish from New York's freshwaters.
Q. Can DEC keep producing hatchery reared fish that contain only small amounts of PCB's?
A. Yes, we believe we can because we specify the ingredients used in our pelleted fish feeds. As such, we can limit the amount of PCB's in the finished feed used at our hatcheries.