Land Between Two Rivers; 304; The Mysterious Freshwater Clam

The following program is made possible through a grant from the Kenny Lindstrom foundation incorporated a charitable trust Mason City Iowa. Home. The mist rising off the Mississippi in the early morning is beautiful but it is oh so mysterious and certainly tenuous. Just so here's our understanding of time. Let's say you go out in a forest and you are supposed to be identifying and study a forest but the only problem was you could only go out in the middle of the night under the dark of the moon

and carry out your study on these conditions. Did it take you a long time through it so this is part of the problem that is involved with with sampling the mollusks. It's one of my ambition. Is to sometime go to a stream and that is crystal clear and you can walk along and see the clams in the bottom of the river so I can just walk along and sample them while I'm standing up without even bending over and that that that's the ideal environment what we do now is wading in mud up to a nice soft poly which means laying on your belly and kind of paddling along looking down with a snorkel and a mask to see what you can see and if it's more than six inches deep you can't see it or diving. With with support equipment. And. Picking things out. One sample at a pass. We're bringing it up to the surface so you can see. What happens. So a lot of the questions that I think

you've asked a lot of the questions that I'd like to answer the only answer is right now we are getting to the point. Where we can start gathering the data. Well here is a trail. That when the special and sandy bottoms they can move along fairly well or when you can sometimes pick up the trail. And track them. OK. And there he is. So you conceived rather prominently how they were buried with only this portion of it sticking. So it was sitting in the substrate like this with that much sticking out which makes it pretty hard to see sometimes. Again laser size. It is we've been finding it takes a lot of searching.

To be sure whether or not the clams are even in your side of things you walk around and they jump up and wave a nice head of flowers at you and say Here I am or here I'm not. We have to work at it to find them. And this means a lot of time a lot of manpower and it hasn't been available because really the whole concept of significance to clams and benthic invertebrates and things like this is only really developing in very recent times. There was interest in birds birds interested and interest in mammals but the idea of having the same amount of interest in. Clams or in insects is kind of a new concept. I had a lot of things we don't know what one of the questions I get asked as a college teacher every once in a while talking about organisms is from students all asking well what good is it. And I'm always tempted to respond to well what good are you. And the appropriate question is to ask what is its role in its natural environment what what function is it

performing. And many times for things like clams we we don't always know all of the intricacies and the balance is going on in terms of regulating things. One of the things that you Nia touched on earlier but it's important to know is the clams are terribly long lived as far as the benthic organisms go crayfish live a year or two at the most. Most of the fish are not terribly long lived and you can get clams that are living 10 12 15 25 years and some no large numbers. So they're very long lived creatures for especially for invertebrates. And as a result they do indicate something about what the environment has been like for a fairly long stretch of time. You can see the hatchets foot there that probably will be recontacted here. It's they belong to the class Pulis supporter which means hatchet footed. That's the shape of that foot that sticks out of the interior and. The Clam moves slowly along the riverbed using this

part of the unique survival of an animal whose life cycle is even more unique. Incredible and inexplicably the eggs are produced they are retained in the gills either in specialized pouches or just in the hollow spaces of the gills and then a modified form that is called the girl kitty kitty looks like a very tiny little size two or three millimeters. At that most structure with two or three very large teeth in this form it causes in its development. And the kidney are expelled out into the water in order for the clam to complete its life cycle a little kitty you have to fasten on the soft parts. Normally it's the gills but it can be the fins and other soft parts of the fish.

After about four or five days it falls off into the bottom and begins to develop the positive insights where they don't get buried by sand or don't get buried by high concentrations of silt. Have a better chance to survive if they get buried by sand or vary by silt faster than they can move upward. They die. So if you have a site in which you have fairly rapid movement of water but not too fast to carry you out of it in which there is fast movement of water so you constantly get a new supply of food being brought in and where you can anchor your your foot to get attached. Then you have an ideal site and I think it's a little bit accidental. Those plants that end up falling in the right places survive if they end up falling around places. So it's kind of like a lottery if you end up in the right location. You can persist in what you persist you can

live for 10 or 15 or 20 years very successfully. You can even live if it gets crowded. Some clam beds we get into on the river. You can take down four in five layers of shell and find nothing. The clamshell all arrive and so you down six seven eight inches and you're still finding shells that are alive. The water can percolate through the spaces between shells and you can get a very large population of shells. Scientists are frustrated because not enough information is available to make informed predictions about clams. One complication is the difficulty of finding clams in their habitat. But by far the major stumbling block is a general lack of interest. This translates to lack of money to perform

basic scientific studies which would begin to unravel the mystery of the freshwater plant. They've been concerned in recent years with die off of clams. One of the problems is that we don't really know how long to live we see how long the clams we collect live how we can age them. But from the beginning of the number that got there in the first place how many lived to be 50 or 60 years old or 20 years old or 10 years old. It's very hard to age the ones that have died because very often they drift downstream and we don't have them at all. So one of the questions that are coming up which I need answers right now is what are the population dynamics how long do clams live. How many clams normally get into a population. Can we estimate right now they're clamming the river a lot. Fish in a river. You said bag limits. And the idea is you don't want to fish more

fish. Then. You can reproduce. They're talking about this in plants but at the present time we just don't know how old. The claim lives and for the commercial ones are they restate reestablishing New South stars and claims coming into the bed so we can continue to take out several hundred Tani's. From a bed here. In Mississippi have a much higher diversity than the Missouri both because of the hydraulics of the river the things they've done to the river amount of salvation that was coming down historically coming down the Missouri all have an effect. The upper Mississippi River the one it's running primarily through limestone. Sold the hardness of the water is relatively high. Lots of calcium which they need to make to make the shell the stability of the

river has been at least over the last 10000 years fairly stable at least in some areas so everything seems to a fit together to make it an ideal place for for native mussels. Up until. Three years last five years 90 percent of the work that was done was done claims in the river. Were primarily taxonomic. The showers were collected usually by Grayling which consists of dragging a long bar with hooks or wires not barred but just hooks and writers that drag down in the sand when they drag into the opening. The clams open shell irritated and closes down on it so you can pull it up and you have a festoon of clams hanging from this from this

bar. This is the traditional way of harvesting plants from the river. Climbing started in the late 80s hundreds when German came from a button factory in Germany he smuggled out the designs to make a button saw a saw that could cut out round blanks. I've showered smuggled over this country move to Muscatine because he had heard that there were a lot of clans in the Mississippi River and built the first button factory that had muskets and. They then began to harvest Chel for the button industry. This developed and expanded a great deal and they could find they brought him. Possibly it was a bigger impact than is presently going on but by the turn of the century areas like the like in the Boston bed

were being completely eliminated. The industry started to slow down at that time by the nineteen twenties had just about disappeared in about at that time. The first of the plastic buttons came in and it became much easier to produce that plastic button stamp it out and polish it than it was to collect the clam shells. We use one. Every day. Tree where you were swing out over the river and drop. That was no money. I can remember. We had batteries to. Mr. game tonight and we could play that.

The news was on because it was battery driven. When they did or where the batteries are. And. When you came to town. You didn't come to town by car. You came to town by the river. In a launch then only on the river. And he worked at very poor. In the daytime so he would launch it in the morning and come to work. Then when he got off work like in the afternoon the four o'clock seven miles. Jail bars or bars all the way down. Home. And take out of the boat. Then the next morning when he went. Back to work. The shells. Put in the bags and in town. Then in the time

six. And in Muscatine. Body. Button. A quite a few people have but machines. And you would cut blanks. And then when you've got say like a. God two and a half gallon pail of blanks. Then you took the blanks down. To the button factory. And they bought the blanks off of you. And then they made but. The days of the robot industry in Iowa are gone just as our frolicking river otters have also disappeared. But playful curiosity still rears his craggy head even in conversation. What are we talking about when we talk about politics and the world chewable and.

Readable time they're pretty hard. You wouldn't wouldn't put it on your favorite list of thanks to you. You know not really. In fact I think when they did a lot of commercial clamming they often go. Through the. Meat away or gave it to hogs or did not use it for human consumption of the classic stories or they used to give them the hogs and the hogs and feed on it hogs like it and then to be hog farmers to go through pig pens and washing down and find pearls because the pearls would be in the meat and then it passed to the hogs and they'd pick them up and in the pig pens It required to hold a little bit of so I think the Mississippi clam population revived after the interest in preventing just fine. In fact not much attention was given to clams until the Japanese discovered a new use for clam shells.

The Japanese developed techniques for culturing pearls. What they do is they take a shower. They grind it maybe I shouldn't say this because it will destroy everybody's illusions. When I first heard about it I had this idea that they would take this sort of kind of it. Spear and stick it in Leave it in the ice there for years and years and years and the big build a bigger and bigger problem you find get a nice big pearl. What they do is they square blanks put it in a roller and roll it to make spears and they make different size spheres they take the sphere put it in the oyster leave it in the year at the most put down about three layers of mother of pearl and then they pull it out. And it's the culture and they can make the cultured any size they want to by varying the size of the blank. I've heard that they can carve the blanks to make them look like little figures put them in and they have little little statues and

things. So there basically is no limit to what they can do. And this at the present time is the major market for for clams and it has been increasing with every year. 65 percent of the shells come out of the Mississippi River. And hang out. For. 20 years. When a serious die off of clams occurred in 1981 a need to environmentalist teamed with commercial climbers seeking stricter regulation of the industry. Concern for the health of the clam population crested now the better informed public wanted to know are we doing enough. But this concern did not result in adequate additional funding to answer basic scientific questions. And without these answers scientists are still unable to develop informed conclusions. The shell was. There in the river and they're just like towns down there. I mean when you you go

down a big bed of shells now you find scattered shells everywhere but you'll find a 3 400 500. Sometimes a thousand tons of shells. Well. A diver. Goes in. Any hand picks the shells. So you're not disrupting the bed you're hand picking in your hand sorting them on the bottom of the river. Everything that goes in that boat. Other than dead shells. Should stay in the boat. And we have rings. Steel rings which. You'll. See. That. The greater. The grades the shills if they're too small. They have to go back in the river. We'll be diving in an area. In the river and there will be any shelters in this.

Area. All of a sudden we've got high water. And it seems like a warship is the silt. The mud. Out of this area. And a guy will grow up and jump in there. And there's just shells over where. I mean there's just. Three or four hundred tons of shells will be in this area where. The year before it was there was nothing in the Mississippi. It's so big. It's so black. Make a lot of diverse A. Black water diving. And. It's so black down there you can see you could be walking on one shell bed right here and the biggest shell bed in the world be right behind you and you never saw it. But I usually just keep all the debate don't you. Want to get down. On Them wire a little case in it. It takes in the. Mirror. Now we take the samples in the fall after the climbing season ended and

for muscle beds in our primary concern about the washboard. One that commercial schollers are interested in that in the three ridge and what we found. Was that the washboard population. At least wasn't as healthy as a three year age and it looked as though that there weren't enough small ones coming in to replace the large ones they were harvesting. And we have a potential here for. Losing at least the abundance of species has in the river if not the species itself. And it's. Important economic importance too because some of the small towns along the river a lot of money is generated in those communities from the harvest of this species. So the DNR and other agencies are concerned about. The economic aspect too. They want the shelters to stand business. They're also concerned that they want that resource to keep.

Being renewable. For as long as they possibly can. We had a very large shell kill. In the river in 81 and 82. And. It was. Big. And they don't they don't have any idea what caused ratio. They and this is. One reason why we passed all these laws. But they don't they don't they're not any closer. To what caused this. Than they were in 81 and 82 when the. Lot of meat was floating down the river it was a conference that was held last June down at Rock Island to try and evaluate whether or not one it was a real die off. And what we could do about it. Most of the Leaning Tower just freshwater Malakal are just in the country were there. They spent two and a half days and they

discovered that one day couldn't decide whether or not it was a real die off in other words whether it was something atypical they couldn't decide rather than would normally die in there in the 10 year period of time. They couldn't tell right they died and they couldn't really evaluate what impact this would have on the populations on a long term basis. That's right very successful. It's interesting in science you sometimes have the feeling that all the good problems have been solved. But if you start looking something that seems as common as this you suddenly start realizing that all the good questions haven't even been asked let alone solved. Back in books we got all big ones that we haven't got any any small ones one of the real questions that I think everybody is starting to ask is. If you look at populations through the smile that has a small one. When you start getting in that's when you start getting in that

small that one is most likely from a girl kitty this year. How much they move. From this stage to the stage you know or do they stay at the same place all the time. No idea. They. Most clams can move. They don't run around but they can move four five seven ten You gave you by crawling by using a foot in dragging themselves to the bottom. To the mud in the bottom so there is some movement. Do they move more than that would they go from a backwater you know it's either hatcheries in the back water and moved. Nobody really knows that this is one of the questions that we don't have the good information yet. Here. Some of the crucial question is the population increasing or

decreasing. The die off that we talk about actually. Affect. Negatively the whole population. What is the percentage of juveniles and adults and does it stay constant over a 10 year period of time. The kinds of values that any game manager would feel it would be an absolute necessity to answer any questions about the health of the health of the species. So a lot of the questions that I think you've asked a lot of the questions that I'd like to answer the only answer is right now we are getting to the point. Where we can start gathering the data. If you look at Pebble. And that feels pretty much the same. So there is a feeling that we have been underestimating. Judo and getting a good picture of what the adults are. But especially with things like planning we're very interested in recruitment right

now it's how many young men are down there or what percentage of the final triumph of a species. These are young adults who are the only place in the south. And this is what they're hoping to find by picking up in sieving complete samples. It would be nice to know whether the clam bed is being replaced in place or does the clam bed start is a barrier you have bottom in gradually over the years accumulating more and more clams because clams end up being accumulated there. And whether we could create a new clam bed can you just dump clams down there. We don't know. Another interesting. Simple question it should be. If you take a clam you take it in your throat in what happens. I don't know. What scientists do know about a clam that is thrown back out of the water is that it will be

carried by the current for a time. But they don't know is whether the clam ever will have the chance to open its shell extend its foot and reattach itself to a substrate. If it is unable to do so and remains closed it will die. Is the future of clam research destined never to open up or would be allowed to attach a foot and prosper is successful commercial clam industry depends on informed answers about freshwater clams a dedicated scientific community not only seeks answers but would like to pose as yet unknown questions. Only time will tell if these people find solutions to their common concerns about the mysterious yet tenacious freshwater plant. Life one to put on its plants in the world one of the number that's long gone.

My nanny. Was. With a wife. Why did you drop down about. It. Wow wow. OK. Drive. Slow son. Let's see if you find. My. I now am I out. OK Roger. One way this program was made possible through a grant from the Kenny Lindstrom foundation incorporated a

charitable trust Mason City Iowa.