From: PO3::"Lynn.Brant@UNI.EDU" 14-FEB-1996 10:51:39.96 To: Multiple recipients of list DIATOM-L CC: Subj: Gyttja getter Dear Diatomists: Several years ago I built a collecting device that has proven useful in collecting sediment and diatoms from the bottom of small ponds and lakes. I believe it was Barbara Winsborough that dubbed this device a "gyttja getter" when she saw it at the NADS in Manitoba. Last year, at the NADS in Iowa, several persons expressed interest in the plans. Since that time I have drawn up a set of "plans" that have been used to make another one or two of these things. I will send a copy to anyone who gives me their mail address (real mail, not e-mail). Let me assure you, this is an extremely simple device. It is essentially a small copper bucket, and it is easy and cheap to make. I made mine without plans on the very first attempt, so it has to be easy! You might want to refine it a bit. E-mail your real mail address to me: LYNN.BRANT@UNI.EDU or write me at: Lynn A. Brant Department of Earth Science University of Northern Iowa Cedar Falls, Iowa 50614 USA Happy gyttja getting! From: PO3::"QUATERNARY@MORGAN.UCS.MUN.CA" "Research in Quaternary Science" 21-FEB-1996 10:46:26.32 To: Multiple recipients of list QUATERNARY CC: Subj: address Vince Vohnout makes beautiful rods. Also locking pistons that do not need a rod to hold them in place during descent of the hole. Also aluminum casing that lo cks together (no threads) so that the inside of the string is smooth. Address i s 3448 Trabue Rd., Columbus OH 43204. (614) 488-9537. vvohnout@magnus.acs.ohio- state.edu From: PO2::"QUATERNARY@MORGAN.UCS.MUN.CA" "Research in Quaternary Science" 22-FEB-1996 19:27:15.05 To: Multiple recipients of list QUATERNARY CC: Subj: Re: corers >My little company here in the Maine woods makes sediment and peat corers of >all types. Mostly we're known for Wright type piston corers and Russian >corers thought we've built several other styles. >We can also help you with MAg-Zirc and aluminum rods plus other >paraphenalia required for coring. >John Erdman >Greenfield Machine Works... jperdman@agate.net In the past year, we had Erdman make a Livingstone for us with rods and a pair of Wright-style toothed core tubes. One of the big advantages of working with them is that John has enough experience now that he can suggest modifications that will improve the effectiveness and efficiency of the equipment, and also note things that have NOT turned out to be such good ideas. We've been quite pleased with workmanship and turnaround time (less than a month from order to delivery). E-mail address WE had was JPERDMAN@aol.com. - Bob Nelson, Colby Geology *********************************************** Alter Ego: The Mad Viking! Robert E. Nelson, Chair Phone: [207] 872-3247 Department of Geology FAX: [207] 872-3555 Colby College e-mail: renelson@colby.edu 5804 Mayflower Hill Drive Waterville, Maine 04901-8858 "Good science consists mostly of play disguised as work." - E. O. Wilson *********************************************** From: PO2::"QUATERNARY@MORGAN.UCS.MUN.CA" "Research in Quaternary Science" 28-FEB-1996 06:13:55.26 To: Multiple recipients of list QUATERNARY CC: Subj: Re: tally counter Dear Pete, We use Psion organisers (pocket computers) instead of Tally counters - when we were looking into buying Tally counters a couple of years ago it turned out the the Psion organisers were much cheaper - they're also quicker, give an on-going record of percentages/concentrations and the data can be plugged directly onto the main computer/spread sheet (via a Comms link). The total cost of an organiser plus comms link is about 100 pounds. Keith Bennett has written a programme for pollen counting on the Psion that can be obtained via FTP from our home page on the www. All the best, Kathy Willis Department of Plant Sciences, University of Cambridge, U.K. From: PO4::"QUATERNARY@MORGAN.UCS.MUN.CA" "Research in Quaternary Science" 28-FEB-1996 08:50:41.96 To: Multiple recipients of list QUATERNARY CC: Subj: Re: tally counter Pete - Try Fisher Scientific (Northeast Regional Office: 52 Fadem Road, Springfield, New Jersey, 07081, U.S.A.). The have manual cell counters with up to eight keys, ranging in price up to $379.00; the 6-unit counter has only five keys and a sixth register for the total of the other five. I'd suggest a pair of the eight-key counters, which would give you 8 wide by 2 high when mounted on a board, for a total of 16 counters at a cost of $758. One could also get three of the 5-key counters to mount them in the configuration closer to what you'd wanted (5 x 3 high); these are $283 each, for a total price of $849. These counters are on page 571 of the 1995/96 Fisher catalogue. They're extremely expensive, I know, but scientific supplies tend to be (in my experience). Unfortunately, almost all other counters I've found are electronic and more expensive still. Hope this helps. - Bob Nelson *********************************************** Alter Ego: The Mad Viking! Robert E. Nelson, Chair Phone: [207] 872-3247 Department of Geology FAX: [207] 872-3555 Colby College e-mail: renelson@colby.edu 5804 Mayflower Hill Drive Waterville, Maine 04901-8858 "Good science consists mostly of play disguised as work." - E. O. Wilson *********************************************** >I am looking for a "bank" of tally counters (at least I think that's what >they are called) for noting pollen counts. A set of 12 (4 x 3 high) would >be perfect. our technician has had a problem finding a supplier of such >counters and they have disappeared from lab. catalogues that we have. >Any information gratefully received. > >Pete Coxon From: PO3::"QUATERNARY@MORGAN.UCS.MUN.CA" "Research in Quaternary Science" 28-FEB-1996 09:52:37.58 To: Multiple recipients of list QUATERNARY CC: Subj: Re: tally counter Pete, I haven't seen any in the cataloges recently, but when they WERE there they were very, very expensive. Far more than a laptop computer, which is what most folks are using these days. Lou Maher distributes a counting program free of charge, as does AASP. Pierre Zippi has one for sale too. http://geology.wisc.edu/~maher/inqua.html http://opal.geology.utoronto.ca:80/AASP/ http://www.alaska.net/~paz/PAZhome.html Others by Jock McAndrews, Aharon Horowitz . . . Owen. Owen K. Davis, Professor 520 621-7953 Department of Geosciences FAX 621-2672 University of Arizona palynolo@geo.arizona.edu Tucson, Arizona 85721 http://geo.arizona.edu/palynology From: PO4::"QUATERNARY@MORGAN.UCS.MUN.CA" "Research in Quaternary Science" 28-FEB-1996 10:04:59.35 To: Multiple recipients of list QUATERNARY CC: Subj: Re: tally counter >I am looking for a "bank" of tally counters (at least I think that's what >they are called) for noting pollen counts. A set of 12 (4 x 3 high) would >be perfect. our technician has had a problem finding a supplier of such >counters and they have disappeared from lab. catalogues that we have. >Any information gratefully received. > >Pete Coxon > Pete, and others, Forestry Suppliers, Inc., of Jackson Mississippi, have eight models of tally counters illustrated in their 1996 Engineering Catalog, page 22. These range from simple, single-counter models to one with two rows of seven counters each. A note at the bottom of the page states that counters are also available in any arrangement, up to 24 counters in a row and up to 12 tiers high. So, if the exact one you need is not illustrated in the catalogue, it is available by special order. Prices available on request from the Order Department, see telephone numbers below. A copy of the catalogue is free. They carry a wide range of scientific equipment, including items for forestry, agriculture, environmental science, limnology, weather, surveying (including GPS), protective equipment, outdoor gear, laboratory equipment, geology, air photo interpretation, and many others. For my needs, they have been one of the first places I turn. No, I do not work there. They are simply one of the best firms I have ever dealt with for scientific equipment. Their address is: Forestry Suppliers, Inc. P. O. Box 8397 Jackson, Mississippi 39284-8397 Telephone numbers: for catalogue requests (800) 360-7788 Sales Department (800) 647-5368, fax (800) 543-4203 International Sales (601) 354-3565, fax (601) 355-5126 TELEX 585330 FORSUP INC JKS I am sorry, they do not have e-mail yet, but are working on it. Hope this helps, Paul _________________________________ Paul R. Larson. Ph.D. Assistant Professor, Geography Physical Science Department Southern Utah University Cedar City, Utah 84720 EUA tel: (801) 865-8244 fax: (801) 865-8051 E-mail larson_p@suu.edu __________________________________ From: PO3::"QUATERNARY@MORGAN.UCS.MUN.CA" "Research in Quaternary Science" 28-FEB-1996 10:43:56.07 To: Multiple recipients of list QUATERNARY CC: Subj: Re: tally counter > > >I am looking for a "bank" of tally counters (at least I think that's what > >they are called) for noting pollen counts. A set of 12 (4 x 3 high) would > >be perfect. our technician has had a problem finding a supplier of such > >counters and they have disappeared from lab. catalogues that we have. > >Any information gratefully received. > > > >Pete Coxon > Ben Meadows carries them. The prices range from $33.50 for a 1-row counter to $245 for a 12-row one. Counters can also be special ordered with desired number of counters and/or tiers and with totalizers. Tel.: 1-800-241-6401 E-MAIL: mail@benmeadows.com WWW address: http://www.benmeadows.com Regards, Jose Valdes From: PO4::"QUATERNARY@MORGAN.UCS.MUN.CA" "Research in Quaternary Science" 28-FEB-1996 11:21:26.34 To: Multiple recipients of list QUATERNARY CC: Subj: Re: tally counter I would recommend calling the Denominator Company for information about their tally counters. You can get their number by calling directory information for Woodbury, Connecticut. Their counters may also still be sold through Forestry Suppliers and other companies, but if you get them directly from the Denominator Company you can request the colors and the order of the colors. Sincerely, Sally Horn University of Tennessee From: PO3::"phoe@FUB46.ZEDAT.FU-BERLIN.DE" "Philipp Hoelzmann" 5-MAR-1996 03:36:08.19 To: Multiple recipients of list PALEOLIM CC: Subj: Re: freeze coring methods Hi everybody! We are using two different freeze-coring methods for sampling baltic lakes in Northern Germany: a) a 3 m long cylindric corer. In this cylindric corer liquid N2 circulates and the sediment freezes (up to 2.7m long and 5-15cm thick) "in situ" at the outside to this corer. There are mainly two difficulties: 1) this method works only up to a water depth of 10m maximum; 2) the method needs a fairly big platform (4x4m) and all this is a lot of work! For reference check: Pachur, Denner & Walter (1984): A freezing device for sampling the sediment - water interface of lakes. - Catena, Vol. 11, p. 65-70. (this is a rather old publication concerning this method and we already modified the system!) b) we are trying these days to construct a more mobile freeze corer: this is a 1.7m long cylindric corer. The hollow inside of this corer is filled with a mixture of "Trockeneis and Aceton" (german terms!)- dry ice (CO2) and aceton- and then the corer -which has a outlet- is shut. Tied to a rope you let the corer (approx.40 kg of weight) sink in the sediment and after 10-15 min. you can recover the corer. This system may be used from smaller boats and you can obtain up to eight profiles per day. Cheers, Philipp. **************************************************** * Dr. Philipp Hoelzmann * * Free University of Berlin - Dept. of Geosciences * * Grunewaldstr. 35, D-12165 Berlin * * Phone: +49 30 838 49 83, Fax: +49 30 838 48 42 * * E-mail: phoe@fub46.zedat.fu-berlin.de * **************************************************** From: PO3::"S30079@PRIME-A.PLYMOUTH.AC.UK" 6-MAR-1996 04:17:02.16 To: Multiple recipients of list PALEOLIM CC: Subj: Freeze coring With reference to the ongoing debate about freeze-coring, perhaps the following paper might be useful: Renberg I. & Hansson H. 1993. A pump freeze corer for recent sediments. Limnol.Oceanogr. 38.(6). pp 1317-1321. _______________________________________________________________________ Mick Cooper Department of Environmental Sciences University of Plymouth Plymouth Tel: + (01752) 233034 PL4 8AA Fax: + (01752) 233035 UK E-mail: s30079@prime-a.plymouth.ac.uk _______________________________________________________________________ From: PO3::"QUATERNARY@MORGAN.UCS.MUN.CA" "Research in Quaternary Science" 7-MAR-1996 15:01:38.80 To: Multiple recipients of list QUATERNARY CC: Subj: drilling/long coring Hello everybody, I am collating information on drilling and long coring (>40 m of sediment) equipment for large and deep lakes. It will be published as an annex to a PAGES brochure on Lake Drilling recommendations. I am looking for: 1 - detailed descriptions of the equipment. I can send a questionnaire I have prepared. 2 - list of references. I would also be pleased to receive a reprint. 3 - descriptions of platforms are also welcome. In existence or ideal ones. I already have: (location in brackets) - Nedra (Siberia) - Foraky (Europe and Africa) - Sedidrill (Europe) - Eurodrill (Europe) - Usinger piston corer (Europe) Missing: - Wright modified Livingstone (N. America, Europe) - others. You can see that the geographical distribution is quite unbalanced. Thank you for your contribution. Suzanne ----------------------- Dr. Suzanne A. G. LEROY Center for Palaeoecology, School of Geosciences, Queen's University Belfast, Belfast, N. Ireland. Ph: +44-1232-335 143 and 245 133 ext. 3978; fax: +44-1232-321 280; e-mail: s.leroy@qub.ac.uk. From: PO3::"dre@MAROON.TC.UMN.EDU" "D.R. Engstrom" 17-APR-1996 09:04:36.50 To: Multiple recipients of list PALEOLIM CC: Subj: Coring Rods Light-Weight Magnesium-Zirconium Alloy Coring Rods Light-weight magnesium alloy drive rods have not been commercially available from drill supply companies for several years. In response to pent-up demand and our own needs for new drive rods, we recently fabricated a modest order for a group of colleagues on an experimental basis. This trial run was eminently successful, both in terms of quality and our ability to supply the rods at a reasonable cost (similar to commercial prices 10 years ago). We have therefore decided to make these rods available to the larger Paleo community on a special order basis. The rods are world-standard EW size: 1-3/8" (3.5 cm) O.D.; a 3-meter length weighs about 6.5 pounds (2.9 kg). The slightly larger diameter of the EW size (compared to the old E-rods), makes them easier to grip but only slightly heavier. Available lengths & cost (shipping charges additional): 1.5-meter $180 2.0-meter $200 3.0-meter $230 The 3-meter lengths are excellent if transportation is not a problem (i.e. you can drive to all your coring sites). The 2-meter rods can be flown as baggage on most commercial airlines. The 1.5-meter rods can be carried by horse or pack-frame. The greater cost/length for the short rods reflects fixed costs for couplings, threading, and fabrication. The rods are internally threaded with world-standard "acme"-type coarse square threads. One end of each rod is fitted with an aluminum alloy coupler that allows rapid coupling/decoupling of rod sections. These Al-couplings are anodized with an extremely hard Teflon-impregnated coating and incorporate small improvements in thread design that should wear better over time. Adapters between the EW size and the old E-rods (and other world mining standards) are commercially available. With each order we include a "connector" coupling that has been internally drilled and tapped to accept the 5/8" threaded stub on the top of most Livingstone-type corers. The treaded hole is fitted with a stainless-steel helicoil insert for greater durability. Information and Ordering Advance ordering is required. Because of the cost of manufacturing these rods, we do not keep a large stock on hand. We plan to begin producing the next set of rods in mid-June and are currently collecting orders from interested individuals. We will need a firm commitment (preferably a signed purchase order) from each participant. Based on previous experience we expect that it will take 3-4 months to fabricate and ship the rods. Please contact either of us by Email (or phone) if you have any questions or wish to place an order. Daniel Engstrom (612-433-5953) Herbert Wright (612-624-5215) St. Croix Watershed Research Station Limnological Research Center Science Museum of Minnesota University of Minnesota Marine on St. Croix, MN 55047 Minneapolis, MN 55455 dre@maroon.tc.umn.edu hew@maroon.tc.umn.edu From: PO2::"dinger@sci.mus.mn.us" "Jim Almendinger" 18-APR-1996 18:19:14.90 To: Multiple recipients of list QUATERNARY CC: Subj: Coring rods Light-Weight Magnesium-Zirconium Alloy Coring Rods Light-weight magnesium alloy drive rods have not been commercially available from drill supply companies for several years. In response to pent-up demand and our own needs for new drive rods, we recently fabricated a modest order for a group of colleagues on an experimental basis. This trial run was eminently successful, both in terms of quality and our ability to supply the rods at a reasonable cost (similar to commercial prices 10 years ago). We have therefore decided to make these rods available to the larger Paleo community on a special order basis. The rods are world-standard EW size: 1-3/8" (3.5 cm) O.D.; a 3-meter length weighs about 6.5 pounds (2.9 kg). The slightly larger diameter of the EW size (compared to the old E-rods), makes them easier to grip but only slightly heavier. Available lengths & cost (shipping charges additional): 1.5-meter $180 2.0-meter $200 3.0-meter $230 The 3-meter lengths are excellent if transportation is not a problem (i.e. you can drive to all your coring sites). The 2-meter rods can be flown as baggage on most commercial airlines. The 1.5-meter rods can be carried by horse or pack-frame. The greater cost/length for the short rods reflects fixed costs for couplings, threading, and fabrication. The rods are internally threaded with world-standard "acme"-type coarse square threads. One end of each rod is fitted with an aluminum alloy coupler that allows rapid coupling/decoupling of rod sections. These Al-couplings are anodized with an extremely hard Teflon-impregnated coating and incorporate small improvements in thread design that should wear better over time. Adapters between the EW size and the old E-rods (and other world mining standards) are commercially available. With each order we include a "connector" coupling that has been internally drilled and tapped to accept the 5/8" threaded stub on the top of most Livingstone-type corers. The treaded hole is fitted with a stainless-steel helicoil insert for greater durability. Information and Ordering Advance ordering is required. Because of the cost of manufacturing these rods, we do not keep a large stock on hand. We plan to begin producing the next set of rods in mid-June and are currently collecting orders from interested individuals. We will need a firm commitment (preferably a signed purchase order) from each participant. Based on previous experience we expect that it will take 3-4 months to fabricate and ship the rods. Please contact either of us by Email (or phone) if you have any questions or wish to place an order. Daniel Engstrom (612-433-5953) Herbert Wright (612-624-5215) St. Croix Watershed Research Station Limnological Research Center Science Museum of Minnesota University of Minnesota Marine on St. Croix, MN 55047 Minneapolis, MN 55455 dre@maroon.tc.umn.edu hew@maroon.tc.umn.edu Posted by: Jim Almendinger phone: 612-433-5953 St. Croix Watershed Research Station fax: 612-433-5924 Science Museum of Minnesota email: dinger@sci.mus.mn.us 16910 152nd St. N Marine on St. Croix, MN 55047 From: PO3::"QUATERNARY@MORGAN.UCS.MUN.CA" "Research in Quaternary Science" 10-MAY-1996 10:15:53.31 To: Multiple recipients of list QUATERNARY CC: Subj: Re: message from Argentina (fwd) I HAVE tried (and watch tried) PVC pipe. If you want a good core, you HAVE to have a piston anchored in place. Otherwise the compression is terrible. In sorted beach sand with shells, using a 4 inch PVC pipe, the compression is slight. With smaller tubes (= greater surface/volume = more friction) the compression in estuary sands is about 50%. I.e., a 1.5 m drive gives 75 cm of sediment. For coring lake muds or organic sediments the recovery is very low. Try rigging a rope through a tennis ball or some other piston inside the PVC pipe, anchor it with a tripod at the surface. Owen. At 06:24 PM 5/9/96 EDT, you wrote: >I haven't attempted this myself, but a good low-cost alternative for coring >in those types of sediment may be a simple PVC pipe. Some people have had >excellent results using a pipe about 10cm diameter pipe hammered into a salt >marsh. They recovered a complete 2m section (large step-ladder is needed so >you can hammer down on the top of the pipe. After hammering the pipe a few >cm into the marsh, they used a 1inch-diam. Dutch corer around the edge of the >pipe to break the vacuum, but I imagine you could improvise something to do >the same. > >Dan Deocampo >Dpt. of Geological Sciences >Rutgers University >Piscataway, NJ > > Owen K. Davis, Professor 520 621-7953 Department of Geosciences FAX 621-2672 University of Arizona palynolo@geo.arizona.edu Tucson, Arizona 85721 http://geo.arizona.edu/palynology From: PO4::"QUATERNARY@MORGAN.UCS.MUN.CA" "Research in Quaternary Science" 10-MAY-1996 16:12:53.75 To: Multiple recipients of list QUATERNARY CC: Subj: PVC cores Greetings all. I too have been using PVC pipe while coring playa and other similar sediments. As Owen Davis notes, a piston is essential for this technique, not just to minimise compression but to prevent sediment being sucked from the bottom of the pipe on extraction. We find that the plugs used by plumbers to close off pipe work well. The diameter of the plug can be adjusted for a snug fit and most importantly they are cheap. If anybody would like details of our cheap and nasty PVC pipe coring kit, please let me know. Cheers, Jon Luly From jperdman@AGATE.NETThu May 1 18:34:14 1997 Date: Fri, 20 Sep 1996 22:03:32 -0500 From: John Erdman Reply to: Research in Quaternary Science To: Multiple recipients of list QUATERNARY Subject: Hand Corers for limnic sediments Aldo - I got your note that was posted on the Quaternary list of which I am a member. I own a small company here in Maine that has a lot of experience in making hand corers. We have been working for several years with the faculty at the Quaternary Institute at the University of Maine manufacturing specialty corers and coring equipment. For the last two years we have been expanding our services to researchers all over the world. In fact we've just shipped full coring systems to Italy and New Zealand. In these cases all communications have been conducted via E-mail, file transfers, and an occasional fax. Most of the people using our corers are coring in environments like those you described. Many are coring in lakes either from ice or boats in depths up to 40 meters and using casings collecting core samples up to 20 meters long. Most of our experience is with the Wright square rod piston corers, any of the Davis-Doyle piston corers, and Russian corers (used for collecting peat from peat bogs). I'm a "retired" PhD and I spent most of my scientific career designing and building scientific equipment. So what we're best at is helping you design or select the exact corer to meet your needs. Or building equipment based on descriptions in journal articles. To get started it would help for me to know a little more about your area of interest. Have you written a research proposal for others that might describe what you intend to do? Could you send it by email? Here are some specific questions that will help define your corer. How deep will the water be? Are you interested in the water sediment interface? How big a core sample do you want? What diameter? How long? How deep into the sediments will you be going? How finely will you be subsectioning your samples? Will there be marsh gasses present? (eg do you need a freeze corer?) What do you expect to encounter in the sediments that will interfere with coring? eg Rocks?, sand? hard marls? undecomposed roots, very soupy sediments? What will you be doing with the core samples eg how will you "work them up" for analyses? Will you be analyzing for trace metals? Aldo - these are just a few of the questions that immediately come to mind. Perhaps you already have a corer design selected? I'm at home now for the weekend. If you are interested, we should exchange a few more email messages. On Monday I can send you some additional information about Greenfield Machine and our corers. I hope we can be of service to you. Greenfield Machine Works Email jperdman@agate.net Greenfield Road Phone 207-827-5557 Costigan, Maine USA FAX 207-827-5557 From dre@maroon.tc.umn.eduThu May 1 18:34:37 1997 Date: Fri, 7 Mar 1997 15:34:44 -0600 From: "D.R. Engstrom" To: Multiple recipients of list PALEOLIM Subject: Mg Coring Rods Light-Weight Magnesium Coring Rods About a year ago we posted a notice on the Paleolimnology listserver about the availability of light-weight magnesium alloy drive rods that we produce on a limited advance-order basis. Our procedure has been to collect a dozen or so orders from colleagues before making a production run. Having completed our second group order, we are now gathering requests for third run early this summer. Orders received by mid-June will be filled around the end of October; a minimum of 4 months is needed to obtain the magnesium tubing and fabricate the couplings. *NOTE* We currently hold a modest inventory of the 1.5-m lengths available for immediate shipment. The following description is repeated from last yearUs announcement: ------------------------------------------- The rods are world-standard EW size: 1-3/8" (3.5 cm) O.D.; a 3-meter length weighs about 6.5 pounds (2.9 kg). The slightly larger diameter of the EW size (compared to the old E-rods), makes them easier to grip but only slightly heavier. Available lengths & cost (shipping charges additional): 1.5-meter $180 2.0-meter $200 3.0-meter $230 The rods are internally threaded with world-standard "acme"-type coarse square threads. One end of each rod is fitted with an aluminum alloy coupler that allows rapid coupling/decoupling of rod sections. These Al-couplings are anodized with an extremely hard Teflon-impregnated coating. ------------------------------------------- Please contact either of us by e-mail (or phone) if you have any questions or wish to place an order. Daniel Engstrom (612-433-5953) Herbert Wright (612-624-5215) St. Croix Watershed Research Station Limnological Research Center Science Museum of Minnesota University of Minnesota Marine on St. Croix, MN 55047 Minneapolis, MN 55455 dre@maroon.tc.umn.edu hew@maroon.tc.umn.edu Dr. D.R. Engstrom St. Croix Watershed Research Station Science Museum of Minnesota Marine on St. Croix, MN 55047 dre@maroon.tc.umn.edu 612-433-5953 (phone) 612-433-5924 (fax)