From pongo@UCLA.EDUTue Apr 29 14:47:43 1997 Date: Mon, 26 Aug 1996 12:34:20 -0700 From: Sean Sumner Anderson To: Multiple recipients of list ALGAE-L Subject: Nutrient Control Hola! Howdy everybody. I am working on growth of the brown alga Zonaria farlowii off of the California Coast. Long story short, I am trying to generate a growth response curve over a range of nutrient (Nitrogen) levels from 0-50umol. I have tried a couple of brands of artificial seawater with no luck. For whatever reason, my fronds just don't dig artificial water. Consequently I have decided to try to use nutrient scrubbers and lower nutrient levels in ambient seawater , and then spike the water up to my various desired levels. So.....I am wondering; 1) Any advice on the scrubber design/problems you have encountered? 2)Many of the people I have spoken with about my artificial seawater problem say the can't get their organisms to grow well in artificial water either. Does anybody have a brand/formula that they find works well with macrophytes? 3) (I think I already know the answer to this one, but it's worth a shot) Does anybody know of a reliable way of increasing ambient (subtidal) nutrient levels in the field? Thanks for any and all help you can send my way! -Sean Anderson *************************** Sean Anderson UCLA Biology Department 405 Hilgard Ave Los Angeles, CA 90095-1606 http://ecomac.botany.ucla.edu *************************** From p.lavery@COWAN.EDU.AUTue Apr 29 14:47:43 1997 Date: Wed, 28 Aug 1996 11:59:09 +0800 From: Paul Lavery To: Multiple recipients of list ALGAE-L Subject: Reply to algal scrubbing [The following text is in the "iso-8859-1" character set] [Your display is set for the "US-ASCII" character set] [Some characters may be displayed incorrectly] >Sean I used a combination of enriched seawater with scrubbing to gain a range of nutrient concentrations for a tissue nutrient vs growth rate study. As with you, a wide range of artificaila media proved useless for growing Chaetomorpha linum and Ulva rigida. The C. linum filasments turned a dark colour and the cell morphology was altered such that they formed shrivelled, twisted filaments ( a bit like a perm gone wrong!) In the end I used a modification of McLachlan's (1973) SWM medium. I simply added a generous dose of Ulva to the seawater to strip N and P from it (a few hours usually got concentrations down to less than 1 µmol. Then I added the supplements to replace those non-N or P nutrients which might also have been depleted and manipulted the N & P concentrations to achieve a range from 0 - 40 µmol P and 0 - 100 µmol N. All the details are in Lavery & McComb 1991 The nutritional ecophysiology of Chaetomorpha linim and Ulva rigida in Peel Inlet, Western Australia. Botanica Marina 34 251-260. The medium worked well and growth rates were equal to or higher than anything observed in the field. None of the morphological changes noted in artificial media occurred in the modifeid SWM. Cheers Paul Lavery > > >*************************** > Sean Anderson > > UCLA Biology Department > 405 Hilgard Ave > Los Angeles, CA 90095-1606 > > http://ecomac.botany.ucla.edu >*************************** From tma@UDEL.EDUTue Apr 29 14:47:43 1997 Date: Tue, 27 Aug 1996 20:37:30 -0400 From: Thomas Arnold To: Multiple recipients of list ALGAE-L Subject: Re: Nutrient Control Sean - Maybe I can help. I've been working on "culturing" a couple brown's for my thesis work. I have the same problem with artifical water(s). Re: the algal scrubbers. Read Walter Addey's papers and his book on scrubbers for home/research aquaria - he is the expert and the book especially is very helpful in designing your own scrubbers. Building one and growing your algal "mats" takes time, of course. I found that it's easier (most of the time) to find low nutrient seawater and add what you need (nitrate, etc.) Off-shore water (in the summer) works best because it usually has low nutrient levels. Re: the field fertilization experiments. I've just finished one where I used slow-release nitrate fertilizer (40-0-0) to fertilize cold-water seaweeds. 200g quantities in porous plastic bottles will last 4-7 days depending on temperatures, exposure, etc. Many people use Osmocote slow release fertilizer (18-10-6; Sierra Corp.) because it has a polymer coating and lasts a long time (1- 1 1/2 weeks). It's great if you don't mind the phosphorous, etc. See papers by Yates and Peckol 1993 (Ecology) and, also, I think there is one by Chapman et al. for use in California kelp beds. The phycological methods book by Littler et al. has a chapter on fertilizing plants in the field and also includes more refs. Hope that helps. Tom Arnold ----------------------- Tom Arnold College of Marine Studies University of Delaware 1(302)645-4008 ----------------------- From malta@CEMO.NIOO.KNAW.NLTue Apr 29 14:47:43 1997 Date: Wed, 28 Aug 1996 10:25:00 PDT From: "Malta, Erikjan" To: Multiple recipients of list ALGAE-L Subject: Re: nutrient scrubbing Sean, With respect to field enrichment; you could try dissolving the nutrients in agar blocks or put them in plastic vials with small holes. See Geertz-Hansen & Sand-Jensen (1992). MEPS 81: 179-183 or Pedersen (1995). Ophelia 41: 261-272. I tried the agar method in aquaria and you get a nice slow release. Succes, Erik-jan. --------------------------------------------------------------------- Erik-jan Malta Malta@cemo.nioo.knaw.nl NIOO - CEMO Vierstraat 28 4401 EA Yerseke the Netherlands tel: (31) (0)113 571920 fax: (31) (0)113 573616 ---------------------------------------------------------------------