Long Lasting Effects of DDT spraying program in New Brunswick

[SwampDonkey]

[CBC,   Environmental Science and Technology Journal - https://pubs.acs.org/doi/10.1021/acs.est.9b01396,  https://www.smithsonianmag.com/smart-news/forty-six-years-after-its-ban-ddt-still-impacts-canadian-lakes-180972417]

More than 50 years after New Brunswick stopped  spraying DDT to kill the spruce budworm, researchers have found "concerning" levels of the banned pesticide in five remote lakes in north-central New Brunswick.

But they were dismayed to find that the levels of DDT in the top layers of sediment were still significantly more than 5 parts per billion, which is considered acceptable by the Canadian Council of Ministers of the Environment. On average, the modern-day sediments were 16 times beyond that level, but one lake was 450 times over the limit. That means DDT and its toxic breakdown products, DDD and DDE, are still hanging around causing problems in those lakes—and likely many more throughout the continent.

The chemical has an aquatic half-life of 150 years, meaning it will take about 750 years before the amount of insecticide trapped in lakes degrades by 97 percent.

Nasty stuff.

[TreefarmerNN]

Certainly not great but the total effect is dependent on transmission out of the sediment.  There are possible vectors, including simply dissolving back into the water but more likely the possible vectors would be in the food chain.  Or it's possible that it will simply remain in the sediments and gradually sink down as it's further covered up. 

Interesting discovery though. 

[SwampDonkey]

The author stated that they are looking at effects on birds and fish in a follow up study. But it's known to pass along from prey to predator and accumulate in fatty tissue. It can also pass along from generation to generation.

[Ianab]

DDT was certainly a problem because of it's widespread use before it's negative side had been discovered. Stopping it's use didn't instantly fix the problem, but those residues aren't in the immediate food chain like they were when it was being carpet bombed on bugs. 

Back then, they sprayed the Mosquitoes, then the bait fish ate them, then the trout ate those, and it was the Bald Eagles that ended up with the toxins and died. 

At least now, with no fresh DDT going into the ecosystem, things are looking up for the Bald Eagles. 

[TreefarmerNN]

DDT was certainly a problem because of it's widespread use before it's negative side had been discovered. Stopping it's use didn't instantly fix the problem, but those residues aren't in the immediate food chain like they were when it was being carpet bombed on bugs.

Back then, they sprayed the Mosquitoes, then the bait fish ate them, then the trout ate those, and it was the Bald Eagles that ended up with the toxins and died.

At least now, with no fresh DDT going into the ecosystem, things are looking up for the Bald Eagles.

It's a very rare day that I don't see multiple eagles.  I'd say they've recovered in our area- dang things are everywhere.

[Magicman]

It's a very rare day that I don't see multiple eagles.

Your profile does not indicate your location?  Maybe you could add it. 

[SwampDonkey]

Eagles and Osprey have recovered here also, no shortage of either. DDT wasn't sprayed as heavy in other areas of the continent as it was here in NB. It was sprayed heaviest here than the rest of Canada. I know it affected brook trout here and might still. If it's in newer sediment, it's in the water settling out.

[TreefarmerNN]

It's a very rare day that I don't see multiple eagles.

Your profile does not indicate your location?  Maybe you could add it. 

Done

[barbender]

In northern MN, we have so many eagles that you have to be careful at times not to hit one that may come flying off a deer carcass in the ditch. 

Me and my daughter were driving a few weeks ago, I saw an eagle soaring above the one side of the road. A glanced ahead of me, and saw a squished morsel of squirrel or something in my lane. Just as I thought, "don't you dare!", the eagle swooped down right in front of us and snatched up the squished bit. If I hadn't noticed it and slowed, we may well have hit it.

The current population is a pretty huge turn around. When I was a kid, it was really something to see a bald eagle. You'd maybe see one a year.

[Magicman]

They are scavengers which is why Benjamin Franklin was against adopting Bald Eagles as the National Bird.  He submitted the Wild Turkey.

[Otis1]

I grew up in a town named Eagle River (WI not AK) also the snowmobile capital of the world., so there's a few eagles around. I have seen them swimming with their wings when they grab too big of fish to fly. Their size is impressive when they fly directly in front of the truck like barbender said. When I lived in CO there was a spot on the river that didn't freeze so there would be dozens of them every winter. 

[SwampDonkey]

My favorite artificial flies for brook trout were the Parmachene Belle, Royal Coachman and the Trout Fin [Sometimes I would use an actual trout fin on a hook]. 

[barbender]

Yes Magic, I see them as vultures with good hair, mostly.

[TreefarmerNN]

They are scavengers which is why Benjamin Franklin was against adopting Bald Eagles as the National Bird.  He submitted the Wild Turkey.

I have a friend who calls them "Bald Headed Buzzards". 

[YellowHammer]

We never saw bald eagles here.  Never.  Now I have a couple living down at the creek and sometimes perch in some of the trees in our yard.  Pretty cool.  

A little off topic, but I don't know about your buzzards, but the ones here are getting dangerous, very numerous, and are becoming pretty aggressive predators.  They are especially bad for the cattle industry, they have developed a habit of killing defenseless calves or pecking their eyes out, and attacking in large flocks.  They can be legally shot when attacking livestock, and I had and friend who, with the permission of the local Game Warden, shot 30 over his cows during calving season.  We got out of the business just about the time it started happening, the last calf we had, there were a dozen perched on the hay ring watching the momma cow, waiting for her to lay down.  Nasty things.   

[barbender]

There's quite a few birds that will go after calves. Golden Eagles are a real problem for sheep ranchers in Wyoming. I think I read that they have to get permits so that they can harass the eagles, to keep them off of lambs. I've also read about ravens and crows going after calves out there.

[TreefarmerNN]

We never saw bald eagles here.  Never.  Now I have a couple living down at the creek and sometimes perch in some of the trees in our yard.  Pretty cool. 

A little off topic, but I don't know about your buzzards, but the ones here are getting dangerous, very numerous, and are becoming pretty aggressive predators.  They are especially bad for the cattle industry, they have developed a habit of killing defenseless calves or pecking their eyes out, and attacking in large flocks.  They can be legally shot when attacking livestock, and I had and friend who, with the permission of the local Game Warden, shot 30 over his cows during calving season.  We got out of the business just about the time it started happening, the last calf we had, there were a dozen perched on the hay ring watching the momma cow, waiting for her to lay down.  Nasty things.   

Most likely those are black vultures and they are nasty birds.  Your friend can get a permit to take them outside of when they are actually attacking livestock.  When I got a permit, I was advised to hang a bird or two from a tree where it's visible to the flock.  Good advice as the flock mostly left that area. 

Turkey vultures aren't that aggressive and the black vultures are.  But turkey vultures have a superior sense of smell so they find carrion first and then the black vultures come in and eat first.  Unfortunately the black vultures have very good sight and are willing to attack livestock that's down or calving.  They typically will peck the eyes out first and then start at the rear end while the animal is still alive.  Nasty, vicious birds.  IMHO- it would be fine with me to cut the flock down to nothing and let the turkey vultures do all clean up duty.

[barbender]

We only have turkey vultures up here, and I've never heard of them going after anything but really good and dead stuff. My Grandpa told me there weren't any of those around when he was young.

[SwampDonkey]

The first turkey vultures I saw up here was around 2012. We never had them here either. The very first ones I saw was in 2001 in Virginia. I never see turkey vultures bother cattle. We don't have a lot of them. Most I see is a couple pairs around here, but near slaughter houses I see a lot more circling around.

[Magicman]

We always had much grief with buzzards and calving.  They would start pecking on a calf before it was delivered.  I have no idea whether Turkey Buzzards were guilty, but I know that the black common buzzards were a bad dudes.

[SwampDonkey]

From what I can find, it's the black vultures that are a nuisance to cows.

https://extension.missouri.edu/publications/g9466

[Ianab]

It's possibly a good thing the NZ's Haast Eagle is now extinct. It's natural prey was Moa birds, that could grow to about 400lb, and Maori legends tell of them attacking people. It's thought they died out in the 1400s after the early Maori ate all the Moa birds. 

But it's not high on my list of species to de-extinct. We've all seen Jurassic Park, how much more warning do you need. 

[YellowHammer]

A 400 lb bird!

Them Jurassic Park bird critters were lucky they never came down south here to Alabama, they wouldn't last a minute.  Every mobile home or trailer park they walked by would be shooting at them!  Hoo wee, that would be a big bucket of fried chicken!    

[Ianab]

I think that's what the old time Maori settlers thought too. They soon ate them all though. 

https://en.wikipedia.org/wiki/South_Island_giant_moa