Problem with short grass flats

I fish a lot of high tide flats with short grass up here in the Morehead City area. Something intriguing is going on this summer. On a lot of the flats I have traditionally fished on in the past the short grass is gone. I am not talking about thinned out, I am talking gone. Flats that used to be covered up with short grass are now bare mud. The fish are also not using these areas like they once did. I only have a few theories as to why this could be happening starting with the low amount of rain we have had this year but I don’t actually know for certain. Anybody have any ideas?

That happens down here sometimes. I read a DNR article where they said that mats of the dead spartina stalks will get stuck on a flat during a flood tide. When the flood tide wanes, the dead spartina stalks sit on the living grass and blocks the sun and the living grass dies- no photosynthesis. The next flood comes in and washes it out leaving the barren mud. This happens alot on the north sides of causeways. It seems that NE winds often coincide with the flood tide (or it will make a smaller tide deeper). The causeways keep the grass from floating with the wind and it causes that same effect. A big tide with a strong SW wind will do the same, but not as often because the SW winds will hold down the tide.

Or it could be an anti-environmentalist herbiphobic spraying herbicides in the marsh. Sounds plausible.

Not sure about your area but I have observed the same phenomenon on a flat in McClellanville. Here’s what happened: on a big flood tide a huge raft of dead spartina grass is created at the furthest edge of the flood. The raft of dead grass hangs up in the short living grass and stays once the water recedes. On a big string of tides this raft gets even bigger (I think it doesn’t go over the places where the really tall grass is because that sticks up enough even during a flood tide to keep the large raft from forming).

When the tides pass you have a four or six inch solid mass of mulch that kills everything beneath it. The grass dies and the stems break off and the roots are dead too, this exposes the mud and creates a soft patch.

if ya gonna be dumb boy you got to be tough - JJ Gray

haha, should have re-checked thread before I posted.

I’ve been wading the same flat for five years now and have seen this happen in once spot and now knowing what it looks like when it’s half grown back in I can say that other parts of that same flat were in the process of growing back when I first found it. Takes a couple of years for it to get back to full cover but in the meantime the fiddler population explodes over that spot where the sunlight makes it all the way top the ground.

Was just saying the other day how I was amazed just how much a flat changes from one year to the next. Unless you go back year after year it’s hard to notice.

if ya gonna be dumb boy you got to be tough - JJ Gray

your grass may have had some adverse reactions to cold winter and snow… the crowns of many a bonefish flat in keys suffered this winter and fish havent been using those places like they used to…

Newman
www.gtownkingfisher.com

Gordon, have you noticed any difference on the flat as to how firm it is compared to the past. Don’t know if it is true (maybe ya’ll can educate me) but I was told the short spartina prefers a firmer or sandier base and the tall spartina usually grows in the deep mud. Could eutrophication (like in freshwater Florida lakes) be taking place and making the flat deeper in mud from the decomposition?

18.5 Baycraft Flats Edition
Johnson 150 Oceanrunner
Wood Driftboat

Some interesting theories. Stuff to ponder. Thanks for the input.

I have seen the same thing on a flat in Beaufort. What I noted though was that the number of periwinkles (I think this is what the snails are) was off the chart. There were 30-40 snails on 1 bare piece of grass, and snails clumped on each other on every rock and shell. I think that on this flat anyway the snails just decimated the grass. On another flat that I fish, there is 25% more grass this year than last.

On the topic of firmer bottom or more mud, the grass is the same spartina here, where the bottom is muddy it grows taller, and where the bottom is firmer or sandier it doesn’t get as much out of the soil so it is stunted and grows shorter.

JohnH

JohnH0802