Plants can be good for fish or bad for fish. All plants are not the
same.

Hydrilla, like most structure, is a great fish attractant. Fish on
the edge of a hydrilla bed and you are likely to meet with some
success. However, the value of hydrilla as nursery habitat is highly
questionable. Navigational difficulties are caused by the growth form
of the plant, which produces a dense surface canopy (top meter or so).
Ecologically, the surface canopy can have devastating effects: it
serves as a barrier between the water column and atmosphere (blocking
gaseous exchange) and prevents light penetration (eliminating primary
productivity except by the canopy). Combined, these factors lead to
degraded water quality. Dissolved oxygen becomes depleted and carbon
dioxide becomes elevated beneath the canopy, both of which are harmful
to fish. Because of the great biomass and high photosynthetic rates,
dissolved oxygen becomes supersaturated in the canopy, and pH often
rises above 10; again, conditions that are harmful to fish. So, in
the presence of topped out hydrilla, the entire water column is, at a
minimum, stressful to fish. Add to the mix the high density of stems
and leaves, which make it difficult for predator species to forage.

In contrast, native species such as eelgrass and pondweeds do not
produce dense surface canopies. Although these species to contribute
to low dissolved oxygen at night, the periods of fish stress are much
shorter in duration and options are available to juvenile fish using
such beds as nursery habitat (they can swim to the surface to "gasp"
for oxygen). Native plant beds do serve as nursery habitat for many
freshwater fish species, including largemouth bass.

When it does not grow to excess, hydrilla benefits the fishery as
structure (not as nursery habitat). Unfortunately, hydrilla has time
and time again spread to occupy all shallow areas in lakes it has
infested, which effectively eliminates all nursery habitat, resulting
in poor bass and/or sunfish fisheries. Again, unfortunately, when
such conditions occur, lake managers often resort to control
techniques that impact all vegetation, which is no better for the
fishery than too much of the wrong kind of vegetation. We need to
find a middle road, folks.

"go-bassn" wrote:

While I'm aware of the problems hydrilla can cause if left unchecked in
SHALLOW waterways, none of the weeds you & Rich quoted compare to hydrilla
for nursery/refuge qualities. Water chestnut is more along the lines of
lily pads (all stem) once you get below the surface. Isn't peppergrass an
emergent weed? And duckweed, isn't that a tiny floating weed? As for
eelgrass, that's probably the last weed bass would gravitate to in a
mixed-weed system. No offense guys, but hydrilla has it over all these weed
types. Navigational problems aside, hydrilla has been responsible for
more bass "booms" on more lakes than nearly any other single factor.

Warren

"Chuck Coger" wrote in message
.. .
agreed.. Rich..
There are several types like eel grass, duckweed, peppergrass that produce
just as well as hydrilla, when the hydrilla isn't choking it out.

I have been on Lakes in Florida that you cant even launch on when the
hydrilla gets high. A few years ago Walk-in-water was completley choked
out,
sure plenty of fish but with no control and you have serious issues, like
not being able to navigate the waterway. The muck it creates to start with
is an issue, and when it decomposes after dying off it takes the oxygen
out
of the area. Hydrilla is little more than pyrrhic victory in a water way,
if
left unchecked it chokes the waterway so you can't fish and eventually
destroyes it, or it is controlled which is expensive to the state and
eventually they will eliminate it all if they can to reduce budgets.

Every few years our lakes in Florida have to be drained and raked to
remove
the muck left behind after the hydrilla has died off in only a few short
years usually 4 or 5. The muck is black which makes our already hot water
even hotter, sure it's nice in the winter for the fish, but its heck in
the
summer. I catch a lot of fish out of Hydrilla, nice fish at that but I
think
given the chance I would trade it for a native species that will also hold
fish.

just my $0.02

---
Chuck Coger

"RichZ" wrote in message
...
Go-bassn wrote:
There's no better
nursery for young bass than a hydrilla bed, few comparable forms of
cover
for adult bass,


Water chestnut.

RichZ
www.richz.com/fishing