Quote:
Originally Posted by Goooh
I agree, can you post the evidence linking lead to the ducks at Catahoula lake?
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I don't have any publications linked but here are a few quotes from our state waterfowl biologist Larry Reynolds (he is actually a member of this site, maybe he can chime in on more specifics). Catahoula Lake is probably one of the most extreme examples just due to the amount of people hunting out there for so long.
"If you want to see lead-poisoning and residual lead in the substrate, come visit Catahoula Lake. We just finished repeating core sampling transects to estimate lead availability in the top 8 inches of soil in this heavily-hunted 35,000 acre habitat to compare with past levels:
1963: 29,964 pellets per acre
1978: 76,452 pellets per acre
1988: 91,388 pellets per acre ......... do you see why implementing non-toxic regs was important in some areas? Look at the increasing trend of lead pellets in the soil.
2011: 81,264 pellets per acre
We pick up dozens of lead-poisoned ducks every year, and if we made any kind of effort to search the cover and lake edge, or run down flightless birds, we would get hundreds or thousands. We also know that one of the first effects of lead-poisoning is increased susceptibility to hunter-mortality, based on higher lead-ingestion rates and blood-lead levels in hunter-killed birds vs those killed/captured using more random methods on the lake during the same period.
and another
"We evaluate ingestion rates at Catahoula Lake every few years by taking gizzards from ducks checked at the boat ramp. None of those hunters thought they killed a lead-sick duck, but our last collection showed over 30% of the diving ducks had ingested lead, and 10% had more than enough pellets to certainly kill them. Most sources of mortality (predation, disease, exposure) are unobserved by hunters under "regular" circumstances."