Converted
05-13-2005, 03:10 PM
I want to share some information that we have received on the hydrilla control issues in the State.
The primary chemical used is Fluridone. Also know by the trade name of Sonar. Traditionally it was used at a level of 3-5 parts per billion (ppb) and was very effective at controlling hydrilla without effecting native vegetation. The hydrilla has mutated at the genetic level to become resistant to those levels. They have increased treatment levels to 5-10 ppb and even in some cases 18-24 ppb. The problem here is that some very beneficial native vegetation cannot tolerate levels above 5 ppb.
The DEP is being forced to revert to contact treatment with aquithal K. It is much more expensive per acre than Sonar but the good news for duck hunters is that it is very selective. No longer will the entire lake be turned into a mud hole. UW-F has provided maps of many lakes in Florida to the FWC and DEP for their use in determining areas to be left untreated. Because of the cost per acre, it is likely that we will get all we are asking for and more.
Now some bad news. The storms of last year have killed a great deal of hydrilla in many of the lakes around the state. The cloudy water that remains has kept both hydrilla and native vegetation from regrowing. DEP beleives that there will be little if any hydrilla control this fall and winter because there is almost nothing to control. This bleak habitat outlook is not good news for the fall flight.
Here are some issues that DEP wants our members to better understand.
1-Spraying for water lettuce and hyacinth does not kill hydrilla. A different chemical (2-4-D) is used. Hydrilla is not affected by that chemical.
2-Mechanical harvesting is not an option except for very limited uses.
A typical mechanical harvester costs $500.00 per acre to operate. Double that cost for each mile between the treatment area and the dump site.
A harvester can cut up to 5 feet deep and cover 2 acres per day. Hydrilla grows at 1" per day. Do the math, the hydrilla would have to be harvested every 60 days. 1 harvester could only handle 120 acres total. It would take over 100 harvesters to work a large flood control lake.
Additionally, harvesters are not selective. They harvest any plant in their path. Since the hydrilla grows much faster than the native plants, after a couple passes the hydrilla would have completely covered and smothered out the native vegetation.
Harvesters also "harvest" up to 30% of the fish and other creatures living in the hydrilla.
3-Timing
The reason given for the Jan-Feb treatment is as follows. For the Sonar to work, they must maintain the treatment level for 60-90 days. The hydrilla will take 3-6 months to die off. Killing it any faster will create a wide spread fish kill due to low oxygen levels in the water. They also want to treat it when it is in a good growth rate so it will suck up the sonar. The flood control people start to lower the lakes for the summer rainy season in April. If the lakes are lowered right after a treatment then the sonar will simply be washed down stream. This is a complicated nut to crack with many agencies involved in this timing. This is not an issue with the contact chemicals so we may be able to have better input on those schedules. There is an issue of dead plants cloging water control structures as well.
DEP is a little confused about many of our comments about particular lakes. They did very little hydrilla control this past year. The hurricanes did much more damage to the hydrilla than any chemicals in 2004.
We may be up against a political battle as follows:
Now that hydrilla is at very low levels statewide, DEP may be pressured by interests in favor of control to "drive a stake in the heart of the beast" In other words, get out there and kill any hydrilla you find and you won't have a problem for many years to come. This would obviously be very bad for duck hunters and we need to be proactive on this issue. I think we need to take the stance that the hydrilla grows faster than any native vegetation so it's return will out pace the native plants no matter what we do. DEP is charged by law to take the health of the wildlife into consideration in their management plans. Lakes that have no plant coverage are certainly not good for fish or waterfowl. The small amounts of hydrilla that remain must not be treated because it is vital to wildlife in light of the terrible condition of many of the state's lakes post hurricane season '04. If we have our way, DEP will likely be critized when the hydrilla is flourishing in a year or two. We need to stand with them and we will gain a very valuable ally.
I must say that this effort by UW-F to influence the spraying has been met with real action at the top levels in FWC and DEP. They really want to know how they can manage the resource better and they are listening to our input.
Your VOICE is being heard!
The primary chemical used is Fluridone. Also know by the trade name of Sonar. Traditionally it was used at a level of 3-5 parts per billion (ppb) and was very effective at controlling hydrilla without effecting native vegetation. The hydrilla has mutated at the genetic level to become resistant to those levels. They have increased treatment levels to 5-10 ppb and even in some cases 18-24 ppb. The problem here is that some very beneficial native vegetation cannot tolerate levels above 5 ppb.
The DEP is being forced to revert to contact treatment with aquithal K. It is much more expensive per acre than Sonar but the good news for duck hunters is that it is very selective. No longer will the entire lake be turned into a mud hole. UW-F has provided maps of many lakes in Florida to the FWC and DEP for their use in determining areas to be left untreated. Because of the cost per acre, it is likely that we will get all we are asking for and more.
Now some bad news. The storms of last year have killed a great deal of hydrilla in many of the lakes around the state. The cloudy water that remains has kept both hydrilla and native vegetation from regrowing. DEP beleives that there will be little if any hydrilla control this fall and winter because there is almost nothing to control. This bleak habitat outlook is not good news for the fall flight.
Here are some issues that DEP wants our members to better understand.
1-Spraying for water lettuce and hyacinth does not kill hydrilla. A different chemical (2-4-D) is used. Hydrilla is not affected by that chemical.
2-Mechanical harvesting is not an option except for very limited uses.
A typical mechanical harvester costs $500.00 per acre to operate. Double that cost for each mile between the treatment area and the dump site.
A harvester can cut up to 5 feet deep and cover 2 acres per day. Hydrilla grows at 1" per day. Do the math, the hydrilla would have to be harvested every 60 days. 1 harvester could only handle 120 acres total. It would take over 100 harvesters to work a large flood control lake.
Additionally, harvesters are not selective. They harvest any plant in their path. Since the hydrilla grows much faster than the native plants, after a couple passes the hydrilla would have completely covered and smothered out the native vegetation.
Harvesters also "harvest" up to 30% of the fish and other creatures living in the hydrilla.
3-Timing
The reason given for the Jan-Feb treatment is as follows. For the Sonar to work, they must maintain the treatment level for 60-90 days. The hydrilla will take 3-6 months to die off. Killing it any faster will create a wide spread fish kill due to low oxygen levels in the water. They also want to treat it when it is in a good growth rate so it will suck up the sonar. The flood control people start to lower the lakes for the summer rainy season in April. If the lakes are lowered right after a treatment then the sonar will simply be washed down stream. This is a complicated nut to crack with many agencies involved in this timing. This is not an issue with the contact chemicals so we may be able to have better input on those schedules. There is an issue of dead plants cloging water control structures as well.
DEP is a little confused about many of our comments about particular lakes. They did very little hydrilla control this past year. The hurricanes did much more damage to the hydrilla than any chemicals in 2004.
We may be up against a political battle as follows:
Now that hydrilla is at very low levels statewide, DEP may be pressured by interests in favor of control to "drive a stake in the heart of the beast" In other words, get out there and kill any hydrilla you find and you won't have a problem for many years to come. This would obviously be very bad for duck hunters and we need to be proactive on this issue. I think we need to take the stance that the hydrilla grows faster than any native vegetation so it's return will out pace the native plants no matter what we do. DEP is charged by law to take the health of the wildlife into consideration in their management plans. Lakes that have no plant coverage are certainly not good for fish or waterfowl. The small amounts of hydrilla that remain must not be treated because it is vital to wildlife in light of the terrible condition of many of the state's lakes post hurricane season '04. If we have our way, DEP will likely be critized when the hydrilla is flourishing in a year or two. We need to stand with them and we will gain a very valuable ally.
I must say that this effort by UW-F to influence the spraying has been met with real action at the top levels in FWC and DEP. They really want to know how they can manage the resource better and they are listening to our input.
Your VOICE is being heard!