A threat to the zerbra mussel???

Murt10

That would be some result. Time will tell.

http://www.nytimes.com/2014/02/25/science/science-takes-on-a-silent-invader.html

ytpe2r5bxkn0c1

I would be extremely cautious of releasing a bacterium into our waterways. The impact on wildlife, farming, and humans could be serious. They have only tested in tanks so how they say it will have no impact on the environment is most peculiar.

tin79

Gatlin Strong Valve wrote: »

I would be extremely cautious of releasing a bacterium into our waterways. The impact on wildlife, farming, and humans could be serious. They have only tested in tanks so how they say it will have no impact on the environment is most peculiar.

Its not a live bacteria. The cells are dead and cannot grow or infect anything. Live Pseudomonas are in every single waterway in the country anyway in amounts vastly higher than could ever be applied in this type of product. They are natural microflora. The way its isolated and delivered direct to the mussels digestive system seems to be what allows this type of product to work. You can see a lot of the background on various sources on the net.

If you do some research online you will see that it has also been tested far beyond tanks. You could look into it before you make your mind up on the statements you have made above. The new generation bio products are very interesting topics. In many ways they are much safer and more targeted than conventional chemical pesticides.

ytpe2r5bxkn0c1

Grand so! But I'll still reserve my right to be wary and somewhat sceptical, having seen decades of such cures that turned into curses. I'm just a contrary grumpy old man, so don't let my opinion annoy you.

rabwaygal

It looks promising but in the article it states it kills more than 90%. This is protenitally not effecient enough.

For example, if 95% of the population are killed, why did the remaining 5% survive? Could they be resitant to the bacterium toxin? If so then it would be similar to the whole overuse/abuse of antibiotics in humans. Because the mussel is so prolific and spreads quickly it would not take the surviving 5% to grow to 100% again, but these will all be resistant to the toxin.

Possibly they should continue to identify toxins and then use them in a staged process to kill the mussel.

I know from an angling point of view some people believe that the zebra mussel hasnt impacted on the fish stocks (and has in fact cleaned the water) but from an infrastructure point of view this needs to be tackled. This is a definite case of prevention is better than cure!!

tin79

Gatlin Strong Valve wrote: »

Grand so! But I'll still reserve my right to be wary and somewhat sceptical, having seen decades of such cures that turned into curses. I'm just a contrary grumpy old man, so don't let my opinion annoy you.

No not at all scepticism is healthy I find . We have all seen to many biocontrol failures over the years. I am not annoyed being a contrary grumpy sort myself!

It is an interesting topic though worth reading on.

tin79

rabwaygal wrote: »

It looks promising but in the article it states it kills more than 90%. This is protenitally not effecient enough.

For example, if 95% of the population are killed, why did the remaining 5% survive? Could they be resitant to the bacterium toxin? If so then it would be similar to the whole overuse/abuse of antibiotics in humans. Because the mussel is so prolific and spreads quickly it would not take the surviving 5% to grow to 100% again, but these will all be resistant to the toxin.

Possibly they should continue to identify toxins and then use them in a staged process to kill the mussel.

I know from an angling point of view some people believe that the zebra mussel hasnt impacted on the fish stocks (and has in fact cleaned the water) but from an infrastructure point of view this needs to be tackled. This is a definite case of prevention is better than cure!!

In the case of this type of biopesticide you don't often see resistance being such a problem as with single entity organic chemicals (Warfarin in rats for example). That's because biopesticides often have complex response pathways that are associated with various different biochemicals. So in many cases its not just one toxin that has the effect. So you get inherently, like you said above, a self regulating staged process.

When you have multiple biochemicals in the process genuine resistance in a population is rarer because it cant be governed by a single gene. And so the process of resistance and inheritance of resistance is much less frequent than it would be again for example with Warfarin in rats.

With massed invertebrate populations (like a mass of Zebra mussels growing on a rock) the % that doesn't die off is really down to exposure considerations. In the case of zebra mussels that could be ones that have been overgrown or just happen not to be feeding during the exposure time. So its more behavioural/circumstantial rather than genetic resistance or increased fitness. If you confirm exposure or dose directly mortality is more or less complete.

The problems with zebras in Ireland are very different to those in the US. In the US some states have climates that allow them to grow all year round. With high levels of food availability you get massive growths that can smother all benthic life. Here we just don't have the same growth potential. In Ireland you would be more looking at smaller scale treatments in industry etc for blocked pipes, inlets and so on. There is not really a need for large scale habitat treatments.

On an ecological side with Zebras, when you introduce them into highly eutrophic lakes, they can work in the anglers favour in the short term by clearing the water and making fish easier to catch. You may even get proliferation of insects in the short term so all looks well.

But overtime the mussels lock up a lot of biomass. The filter out a lot of the phyto and zooplankton and out compete native organisms like Daphnia. Over time that diminishes the food chain and leaves less biomass for fish etc because a lot of the fish species here cant feed on the adult mussels very well. So you get masses of live mussels growing over masses of dead ones with a lot of sequestered nutrients. Again in certain circumstances that's ok if you have excess nutrients in the water but over time it tends not to be.

I have seen videos taken by divers over areas of heavy infestation of zebra mussels and (particularly) of Asian clams and there is literally nothing else growing. They smother native bivalves and literally coat the bottom when the substrate is suitable. Somewhat luckily for us we seem to be at the extreme range of what the zebras can tolerate, they don't like acid pHs (that's why you see them in the limestone rivers and lakes most) and low temperatures.

OwenM

If they grow in such huge numbers, would they have a contribution or role to play in carbon sequestering because of all their shells?

tin79

OwenM wrote: »

If they grow in such huge numbers, would they have a contribution or role to play in carbon sequestering because of all their shells?

I would have thought their biomass on a global scale would not be all that high. Not compared to plants anyway.