What's the Deal??

[Silver Creek]

Anyone know what is going on? I saw this on another BB but I am completely ignorant. It is alarmist? Is is a real threat.

http://sports.espn.go.com/outdoors/s...ory?id=4975762

I definitly agree with the comment in the article about lead sinkers. There is no evidence that lead sinkers are threatening populations of water birds.

[Esopus Guy]

Lead shot is banned from sell in NY for this very reason. I have a hard time getting it sent to NY from some places.

[Silver Creek]

Hi Esopus,

I wrote some stuff on lead toxicity from fishing weights for the Wisconsin FF BB because there is a move to ban lead weights based on shoddy assumptions. I won't post it unless there is an interest by folks who want to answer critics with scientific research that shows that fishing weights are not threatening water bird populations.

[Esopus Guy]

On that note. Can any one send me some Black bird shot. Comes in tube dispensers. No carriers will send to NY. Best shot i've ever used. Impossible to get off your line.

[AaronJasper]

Silver Creek,

I would definitely like to see your scientific data on the actual effects of lead in streams. I was talking to a friend about this the other day. I can't see it having the effect to the extent that some would lead us to believe. He was also bringing up the fact the flourocarbon tippet is also harmful, when dispensed into the stream. While I do agree that to be fact, is it any worse than regular nylon? I know that nylon does break down sooner than flourocarbon. However, one can argue back with the fact does a 1,000 years more matter when we are talking about thousands of years already? I am sure that you have done a lot of research on this due to your scientific background. I would be very curious to read your opinions as to what the facts really are here.

About the "ban" on fishing.... Obama has done a lot of things that i don't think are right for this country, but when we are faced with so many dire situations both overseas and right here in our back yard that they would be wasting out countries resources on trying to ban access to sportfishing. I guess that going "green" means keeping our youth inside playing video games rather than fishing with their parents. My blood pressure was up just a tad while reading that article.

[rs0i]

I have recently visited the Tamarack Wildlife Rehabilitation and Education Center while trying to keep a young blue heron from starving after a big storm in Western Pa. They showed me a number of eagles that they were trying to save that were dying from the effects of lead poisoning. The bald eagles were poisoned from eating fish of course.

Also, there was a special on bald eagles on PBS this year, I think it was on Nature, that documented bald eagle deaths due to lead poisoning.

Ducks and other waterfowl and especially Ospreys were ravaged in certain areas not only from DDT use, but from eating lead pellets deposited in the water from shotgun shells that didn't find their mark.

There isn't a stream, river or lake in the U.S. that doesn't have some toxins present, generally PCBs and Mercury (from Coal burning plants). Just look in the back of the PA Fishing Summary or PFBC site for the Fish Consumption Advisory.

Canada has banned lead shot and sinkers because of its documented effects on wildlife. See two sites below for documentation, and there are more. It is not hard to find.

So why add more lead to the mix when we don't have to??? Use zinc.

http://www.michigan.gov/dnr/0,1607,7...6676--,00.html

http://www.cws-scf.ec.gc.ca/index_e.cfm

[VTflyfishing]

[quote author=Silver Creek link=topic=4197.msg33117#msg33117 date=1268152220]


I definitly agree with the comment in the article about lead sinkers. There is no evidence that lead sinkers are threatening populations of water birds.
[/quote]

That is not true at all. You should get your facts right. rsOi is 100% correct in his post. Why add more poison to our waterways when there are alternatives.

[Silver Creek]

The study that is most often quoted is one from Tuft's University in Massachusetts showing that 52% (16) of 31 dead loons examined by them died of lead fishing weight ingestion. This study was published in 1992 and this started the move to ban lead fishing weights.

"Of the 75 loons received, 31 adults were examined. Sixteen of these adult birds (52%) died from lead poisoning."

See Pokras, M.A. and R. Chafel. Lead toxicosis from ingested fishing sinkers in adult common loons (Gavia immer) in New England. Journal of Zoo and Wildlife Medicine 1992. 23: p. 92-97. From:

http://www.jstor.org/pss/20460274

However this death rate of 52% was much greater than death rates found by other researchers. The US Government funded a cooperative study through the U.S. Geological Survey, National Wildlife Health Center, 6006 Schroeder Road, Madison. This was a cooperative study from 5 scientific organizations - U.S. Geological Survey, National Wildlife Health Center; Department of Veterinary Sciences, University of Wyoming; BioDiversity Research Institute, Falmouth, ME; Arizona Cooperative Fish and Wildlife Research Unit, School of Renewable Natural Resources University of Arizona; and the Vermont Cooperative Fish and Wildlife Research Unit, University of Vermont. The study was of dead waterfowl including over 300 dead loons collected from 9 states: Minnesota, Wisconsin, Maine, New York, New Hampshire, North Carolina, Florida, California and Alaska.

I believe this is the most reliable study of the effect of the toxic effects fishing weights. It does not include deaths from bullets and lead shotgun pellets like most other lead toxicity studies do.

"From 1995 through 1999, 2,240 individuals of 28 species of waterbirds were examined in the United States for ingested lead fishing weights. A combination of radiography and visual examination of stomachs was used to search for lead weights and blood and liver samples from live birds and carcasses, respectively, were collected for lead analysis. Ingested lead weights were found most frequently in the Common Loon (Gavia immer) (11 of 313 = 3.5%) and Brown Pelican (Pelecanus occidentalis) (10 of 365 = 2.7%), but also in one of 81 (1.2%) Double-crested Cormorants (Phalacrocorax auritus) and one of 11 (9.1%) Black-crowned Night Herons (Nycticorax nycticorax). "

http://www.nwhc.usgs.gov/disease_inf...ds_sinkers.pdf

The Minnesota DNR also did their own study of the death rate of loons due to lead fishing rates.


http://www.dnr.state.mn.us/eco/nonga...s/leadout.html


"Out of 101 dead loons that were analyzed, a total of seven died of lead poisoning and an equal number died of fish line entanglement." That 7% rate includes both lead from bullets and shotguns as well as fishing weights. The actual rate was just over 5% due to fishing weights.

It is obvious that the data from Tufts is not constant with the wider survey data from the US Government's National Wildlife Health Center. One of the authors of this report is the Biodiversity Institute in Gorham, ME. They are experts in toxins especially mercury toxicity.

Why would the Biodiversity Institute, an expert in heavy metal toxicity not include the Tuft's data? The only conclusion that seems plausible is that the data from Tufts was a special situation that does not apply to the country as a whole as determined by the U.S. Geological Survey, National Wildlife Health Center.

I found this explanation, ""Although the rates were much lower in the NWHC study, there is no doubt that lead-sinker mortality is higher in New England than in other parts of the country. The variance appears to be a result of the different character of lakes (and loons) in the two regions. Pokras points out that the heaviest incidence of lead poisoning occurs in a heavily fished 5-lake region in New Hampshire. The lakes, most of which are only a short drive from Boston, are deep, clear, infertile and very heavily developed. As he described the situation, “on weekends, you can walk across the lake from boat to boat.” There are practically no natural nesting areas, so the birds nest on floating platforms installed by loon-preservation groups. The loons commonly hang around docks and fishing boats, hoping to pick up lost or discarded bait, a behavior that greatly increases their odds of ingesting fishing gear. Adding to the problem is the fact that the lake basins have a high density of lost sinkers that are easy to see because the bottoms are so clean."

If the 50% of loons were dying of lead toxicity nationally and specifically in my state of Wisconsin, one would expect and effect on loon populations and other waterfowl.

There is a proposal to ban lead weights in Wisconsin but the most recent data shows that populations (Eagles, Osprey, Loons and Trumpeter Swans) that are supposedly at risk from lead fishing weights are actually INCREASING and not decreasing.



http://dnr.wi.gov/org/land/wildlife/...preysurv08.pdf


http://www.northland.edu/sigurd-olso...ion-survey.htm

http://www.dnr.state.wi.us/org/water...on-Project.pdf

http://whyfiles.org/015species_restore/swan.html


http://library.fws.gov/Bird_Publicat...swan_pop00.pdf


"A central tenant of fish and wildlife management is management for the optimal overall population level, not for the well being of any one individual. Simply put, sustaining populations is the goal of fisheries and wildlife management, not sustaining individuals."

"It is not disputed that lead toxicosis may harm or kill loons and other water birds. This fact is well documented. The pivotal question is: are loon populations, and populations of other water birds, significantly reduced by lead sinker ingestion? Or phrased in a more comprehensive fashion: is mortality from lead toxicosis in loons and other water birds high enough to threaten self- sustaining loon populations? Based on available research the answer to both of these questions is no."

"This determination is based on a comprehensive 1999 study requested by the U.S. Fish and Wildlife Service, Division of Federal Aid and conducted by the National Wildlife Health Research Center in Madison, Wisconsin......the results showed that only 3.5% of common loons (from a sample of 313) had ingested lead sinkers and just 27 of 36,671 waterbird and bald eagle carcasses (0.007%) contained ingested lead sinkers"

http://www.asafishing.org/images/gov...d_position.pdf




The FEDERAL GOVT'S OWN RESEARCH to study the effect of lead fishing weights showed at most only 3.5% of the deaths were due to lead weights. Other water birds had LESS that 3.5% lead weight ingestion. Now consider that the death rate from C&R fishing varies from 3-5% per fish per release, and some fish are caught multiple times. It then becomes apparent that a maximum 3.5% death rate from lead fishing weights in birds is probably less than the cumulative population deaths from C&R fishing in trout. Why not ban C&R fishing using that same logic?????

Shouldn't there be evidence that lost lead fishing weights are affecting wildfowl populations before any ban is passed? If lead weights are responsible for a maximum of 3.5% of the death of loons, why not ban C&R fishing on that same basis.

It should also be noted that no one has studied the effect of lead fishing weights on the deaths of water fowl feeding on river systems. The data that is used to ban trout fishing weights on rivers are based on erroneous data from a unique situation on some lakes in New England.

We base threats to wildlife based on population studies. That is how we determine endangered and threatened species. That is exactly how we justify C&R fishing as a renewable resource. The threat of lead based fishing weights should be based on that same logic.

[Silver Creek]

There is no cheap substitute for lead that is near the specific gravity of lead. Tungsten is dense but solid tungsten is not soft. Soft forms of tungsten are composed of tungsten particles and a soft carrier that lowers the overall density. Tin is often used as a substitute for split shot, but tin alloy shot is not near the density of lead. Silver is the closest for both malleability and density.



Here are the specific gravities of some metals in comparison to lead.

Tungsten 19.0
Tantalum 16.6
Lead 11.342
Silver 10.5
Molybdenum 10.2
Bismuth 9.781
Copper 8.89
Nickel 8.85
Monel 8.80
Cobalt 8.71
Iron 7.87
Tin 7.29
Zinc 7.14

Tin is 2/3 the specific gravity of lead. You would need 50% more tin to equal the weight of lead but you would also have a greater volume that would decrease the sink rate even if the weights were identical. In addition, where density per volume is critical as in wrapping lead wire in fly construction, I have not found anything yet that is the equal of cheap lead wire. Silver wire would be the closest but it is not as malleable.

Tungsten is heavier than lead but it is not malleable and must be compounded with a carrier substance that lower's the net specific gravity if it is to be used as a substitute for split shot. I have seen no comparisons of the net specific gravity of tungsten compounds compared to lead.

[AaronJasper]

I can't wait to read this after my talk tonight!