{"id":324,"date":"2011-01-01T00:00:01","date_gmt":"2011-01-01T00:00:01","guid":{"rendered":"https:\/\/info.calcofi.com\/2011\/01\/01\/primary-productivity\/"},"modified":"2011-01-01T00:00:01","modified_gmt":"2011-01-01T00:00:01","slug":"primary-productivity","status":"publish","type":"post","link":"https:\/\/mindwander.com\/index.php\/2011\/01\/01\/primary-productivity\/","title":{"rendered":"Primary Productivity Methods"},"content":{"rendered":"

\n\tPRIMARY PRODUCTIVITY <\/o:p><\/span><\/h2>\n

\n\t <\/o:p><\/p>\n

\n
\n<\/div>\n

\n\tOVERVIEW: Primary production is estimated from 14<\/span>C uptake using a simulated in situ<\/i> technique in which the assimilation of dissolved inorganic carbon by phytoplankton yields a measure of the rate of photosynthetic primary production in the euphotic<\/span> zone.<\/p>\n

\n
\n<\/div>\n

\n\t <\/o:p><\/p>\n

\n\t1. Principle<\/span><\/h3>\n

\n\tSeawater samples are incubated with a radioactive substrate to determine the incorporation of inorganic carbon into particulate organic carbon due to photosynthesis <\/span>at selected light levels.  <\/span>The data have units of mg-carbon per m<\/span>3<\/sup><\/span> per half day.<\/span><\/p>\n

\n\t2. Productivity Cleaning Procedures <\/span><\/o:p><\/h3>\n\n\n\n\n\n\n
\n

\n\t\t\t\t\t2.1.<\/p>\n<\/td>\n

\n

\n\t\t\t\t\tMicro-90 Cleaning solution is diluted to 2% solution using de-ionized water (DW).  <\/span>Hydrochloric acid (HCl<\/span>) Trace Metal Grade, Fisher Scientific, solution (1.2M) diluted with DW. Acid-washing of Teflon should be done with great care as Teflon is porous to HCl<\/span> which can compromise dilute basic stock solutions of 14<\/sup>C -bicarbonate.<\/p>\n<\/td>\n<\/tr>\n

\n

\n\t\t\t\t\t2.2.<\/p>\n<\/td>\n

\n

\n\t\t\t\t\t250 ml polycarbonate incubation<\/span> bottles are filled to capacity with 2% MICRO for 3 days with the cap on in an inverted position. <\/span>Next, rinse all Micro away and then rinse down the walls with 20 -30mls 10%HCl and recap and shake  <\/span>to<\/span> acid rinse inside bottle.  <\/span>This should be left overnight 12-16 hours. The acid is removed by rinsing the bottles three times with milliQ<\/span> clean water before air drying.<\/p>\n<\/td>\n<\/tr>\n

\n

\n\t\t\t\t\t2.3.<\/p>\n<\/td>\n

\n

\n\t\t\t\t\t10 liter rosette sample bottles are cleaned with a 2% MICRO soak for 3 days, rinsed with de-ionized water and then dipped in 10% metals free HCl<\/span>.  <\/span>Caps, special coated springs and valve assemblies are also cleaned with a 2% MICRO soak for 3 days and then rinsed with de-ionized water and dried.  <\/span><\/p>\n<\/td>\n<\/tr>\n

\n

\n\t\t\t\t\t2.4.<\/p>\n<\/td>\n

\n

\n\t\t\t\t\tAll lab ware to be used is cleaned in this manner.<\/p>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

\n\t <\/o:p><\/p>\n

\n\t3. Preparation  <\/span>of<\/span> Isotope Stock <\/span><\/o:p><\/h3>\n\n\n\n\n\n\n\n
\n

\n\t\t\t\t\t3.1.<\/p>\n<\/td>\n

\n

\n\t\t\t\t\tTo prevent contamination of self or solutions, work with the isotope stock is performed wearing vinyl gloves.<\/p>\n<\/td>\n<\/tr>\n

\n

\n\t\t\t\t\t3.2.<\/p>\n<\/td>\n

\n

\n\t\t\t\t\tA solution of 0.3 g of Na2<\/sub>CO3<\/sub> anhydrous (ALDRICH 20,442-0, 99.995%) per liter Milli<\/span>-Q filtered DW in a Micro cleaned 1 liter Teflon bottle to yield a concentration of 2.8 mM<\/span> Na2<\/sub>CO3<\/sub>.   <\/span>This solution is filtered through 0.2\u00b5M Nucleapore<\/span> filter to remove particulate carbonate.<\/p>\n<\/td>\n<\/tr>\n

\n

\n\t\t\t\t\t3.3.<\/p>\n<\/td>\n

\n

\n\t\t\t\t\tConcentrated stock, 50ml of NaH-14<\/sup>CO3<\/sub> (~50-57 mCi<\/span> mmole<\/span>; MP Biomedicals<\/span> LLC.) was diluted with 350 ml the 2.8mM Na2<\/sub>CO3<\/sub> solution in productivity-cleaned 1 liter polycarbonate graduated cylinder.  It has become necessary to pH this up with an ultra clean 1N NaOH solution to raise the pH to ~10.<\/p>\n<\/td>\n<\/tr>\n

\n

\n\t\t\t\t\t3.4.<\/p>\n<\/td>\n

\n

\n\t\t\t\t\tSpecific activity can be checked by diluting the above made solution to working concentrations, ie<\/span> 50-200\u00b5l added to 250ml polycarbonate centrifuge bottle and measuring out triplicate 1ml portions into beta ethanolamine spiked (1.5%v\/v) Ecolume<\/span> scintillation cocktail.<\/p>\n<\/td>\n<\/tr>\n

\n

\n\t\t\t\t\t3.5.<\/p>\n<\/td>\n

\n

\n\t\t\t\t\t <\/span><\/sup>To check for  <\/span>14<\/sup>C<\/span>-organic carbon contamination another working aliquot of 200\u00b5l can be placed into a scintillation vial and acidified with 0.5ml 10% HCl<\/span> and placed on a shaker overnight. This is done in the hood as it liberates 14<\/sup>C-CO2<\/sub>. The acidified dpm should be <0.0001% of the total dpm of the 14<\/sup>C preparation.<\/p>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

\n\t <\/o:p><\/p>\n

\n\t4. Incubation Systems: situ incubation techniques<\/span><\/h3>\n\n\n\n\n\n
\n

\n\t\t\t\t\t4.1.<\/p>\n<\/td>\n

\n

\n\t\t\t\t\t <\/span>Incubation apparatus consists of seawater-cooled, temperature monitored incubator tubes wrapped with neutral-density screens which simulate in situ<\/i> light levels.     <\/span><\/p>\n<\/td>\n<\/tr>\n

\n

\n\t\t\t\t\t <\/o:p><\/span><\/p>\n<\/td>\n

\n

\n\t\t\t\t\t <\/o:p><\/span><\/p>\n<\/td>\n<\/tr>\n

\n

\n\t\t\t\t\t4.2.<\/p>\n<\/td>\n

\n

\n\t\t\t\t\tSix incubation depths are selected, they represent 56, 30, 10, 3, 1  <\/span>and<\/span> ~0.3 % light level.  <\/span>These values are estimated using a wand type PAR meter after cleaning tubes and screens covering them.  The near surface light level is reduced to 56% using common plastic screening to prevent a lense effect and subsequent cooking of the surface samples. <\/p>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

\n\t <\/o:p><\/p>\n

\n\t5. Sampling <\/span><\/o:p><\/h3>\n\n\n\n\n
\n

\n\t\t\t\t\t5.1.<\/p>\n<\/td>\n

\n

\n\t\t\t\t\tPrimary productivity samples are taken each day shortly before local apparent noon (LAN).  <\/span>Light penetration was estimated from the Secchi<\/span> depth (Using the definition that the 1% light level is three times the Secchi<\/span> depth).  <\/span>The depths with ambient light intensities corresponding to light levels simulated by near surface and the on-deck incubators were identified and sampled on the rosette up-cast.  <\/span>Extra bottles were tripped in addition to the usual 20 levels sampled in the combined rosette-productivity cast in order to maintain the normal sampling depth resolution.<\/p>\n<\/td>\n<\/tr>\n

\n

\n\t\t\t\t\t5.2.<\/p>\n

\n\t\t\t\t\t <\/span><\/p>\n

\n\t\t\t\t\t
\n\t\t\t\t\t5.3.<\/p>\n<\/td>\n

\n

\n\t\t\t\t\tUsing a dark sleeve to subdue the light, water samples are transferred to the incubation bottles (250 ml polycarbonate bottles) and stored in a dark box until inoculation.  <\/span><\/p>\n

\n\t\t\t\t\t <\/o:p><\/p>\n

\n\t\t\t\t\tTriplicate samples (two light<\/span> and one dark control) were drawn from each productivity sample depth.<\/p>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

\n\t <\/o:p><\/p>\n

\n\t6. Isotope Addition and Sample Incubation <\/span><\/o:p><\/h3>\n\n\n\n\n\n
\n

\n\t\t\t\t\t6.1.<\/p>\n<\/td>\n

\n

\n\t\t\t\t\tSamples are inoculated with 50-200 \u00b5l of 14<\/sup>C as NaHCO<\/span>3<\/span> <\/span>stock solution of sodium carbonate (Fitzwater et al<\/i>., 1982).<\/p>\n<\/td>\n<\/tr>\n

\n

\n\t\t\t\t\t6.2.<\/p>\n<\/td>\n

\n

\n\t\t\t\t\tSamples are incubated from LAN to civil twilight in a surface seawater-cooled incubators<\/span> with neutral-density screens which simulate in situ<\/i> light levels, corresponding to those from which samples were taken (see 4.2)<\/span>.<\/p>\n<\/td>\n<\/tr>\n

\n

\n\t\t\t\t\t6.3.<\/p>\n<\/td>\n

\n

\n\t\t\t\t\tAt civil twilight the incubation is terminated and the time noted.  <\/span>Sea state and safety is the only exception accepted to delay the end time.<\/p>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

\n\t <\/o:p><\/p>\n

\n\t7. Filtration <\/span><\/o:p><\/h3>\n\n\n\n\n\n
\n

\n\t\t\t\t\t7.1.<\/p>\n<\/td>\n

\n

\n\t\t\t\t\tAt the end of the incubation, all bottles have subsamples of 10mls removed for DO14<\/sup>C analysis. The LTER DOC filtrate apparatus consists of a plexi<\/span>-glass filtration manifold to hold up to 18 scintillation vials over which syringe needles with 0.45um equivalent micro-syringe filters can be passed through stoppers with 25 ml syringe bodies serving as filter funnels.  <\/span>The exception to this is dark bottles are only sampled for DO14<\/sup>C on two each high and low chlorophyll stations.<\/p>\n<\/td>\n<\/tr>\n

\n

\n\t\t\t\t\t7.2.<\/p>\n<\/td>\n

\n

\n\t\t\t\t\tAdditionally, from dark bottles a 1ml sample is placed into beta mercapto<\/span>-ethanol spiked (1.5%v\/v) Ecolume<\/span> scintillation cocktail  <\/span>to<\/span> determine the specific radioactivity in the samples.   <\/span>These values are used to calculate an average cruise value after removing outliers.<\/p>\n<\/td>\n<\/tr>\n

\n

\n\t\t\t\t\t7.3.<\/p>\n<\/td>\n

\n

\n\t\t\t\t\tFinally the samples are filtered onto Millipore HA filters and placed in scintillation vials.  <\/span>One half ml of 10% HCl<\/span> was added to each sample.  <\/span>The samples are then allowed to sit, without a cap, at room temperature for at least 3 hours (after Lean and Burnison<\/span>, 1979).<\/p>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

\n\t <\/o:p><\/p>\n

\n\t8. 14<\/sup>C Sample Processing <\/span><\/o:p><\/h3>\n\n\n\n\n
\n

\n\t\t\t\t\t8.1.<\/p>\n<\/td>\n

\n

\n\t\t\t\t\tAfter addition of 10mls of Ecolume<\/span> cocktail, vials are tightly capped and mixed before vials are counted for up to 10 minutes each for 14<\/sup>C  <\/span>on<\/span> a Beckman 6100LC liquid scintillation counter set to 1.0% counting precision.<\/p>\n<\/td>\n<\/tr>\n

\n

\n\t\t\t\t\t8.2.<\/p>\n<\/td>\n

\n

\n\t\t\t\t\tData is captured to a flat file using Beckman data capture software for Windows in ASCII format.  <\/span>This format is then used to integrate productivity depths into the CalCOFI<\/span> data processing flow.<\/p>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

\n\t <\/o:p><\/p>\n

\n\t9. Calculations<\/span><\/h3>\n

\n\tData is presented as mean mg Carbon assimilated per meter cubed of seawater for one half light day.  <\/span><\/p>\n

\n\tmgC\/m3 <\/sup>per one half light day <\/span>=  <\/span>((Sampledpm<\/sub><\/span><\/span> <\/span><\/sub>\u2013 Blankdpm<\/sub><\/span>) x W)\/R, where<\/span><\/p>\n

\n\t <\/span><\/p>\n

\n\t   <\/span>W = 25200 = 12,000 x A  <\/span>x FT<\/span><\/sub>  <\/span>x 1.05<\/p>\n

\n\t   <\/span>12,000= molecular weight of carbon in milligrams<\/p>\n

\n\t   <\/span>A = carbonate alkalinity (milliequivalents<\/span>\/liter)<\/p>\n

\n\t   <\/span>FT<\/span><\/sub> = Total carbon dioxide content\/ carbonate alkalinity<\/p>\n

\n\t   <\/span>1.05 is the 14<\/sup>C isotope fractionation factor, reflecting preferential use of C12 over C14 by a factor of 5%<\/p>\n

\n\t   <\/span>R = dpm added to sample (\u00b5Ci\/200\u00b5l x 2.2 x 106<\/sup>)<\/p>\n

\n\t <\/p>\n

\n\tTo better understand this equation and variables see Strickland and Parsons (1968).<\/p>\n

\n\t10. Equipment\/Supplies<\/span><\/h3>\n

\n\t\u00b7         <\/span><\/span><\/span>10 liter pri<\/span>. prod<\/span>. cleaned sampling bottles<\/p>\n

\n\t\u00b7         <\/span><\/span><\/span>Secchi<\/span> disk<\/p>\n

\n\t\u00b7         <\/span><\/span><\/span>Re-pipet<\/span> dispensers for delivering 20\u00b5l, 200\u00b5l, 0.5ml<\/p>\n

\n\t\u00b7         <\/span><\/span><\/span>Pipets<\/span> able to measure 1ml and 10ml<\/p>\n

\n\t\u00b7         <\/span><\/span><\/span>250 ml polycarbonate centrifuge bottles<\/p>\n

\n\t\u00b7         <\/span><\/span><\/span>liquid scintillation counting (LSC) vials<\/p>\n

\n\t\u00b7         <\/span><\/span><\/span>Seawater plumbed incubation rack with neutral density screening.<\/p>\n

\n\t\u00b7         <\/span><\/span><\/span>Par meter, wand type (Biospherical<\/span> Instruments)<\/p>\n

\n\t\u00b7          <\/span><\/span><\/span><\/sup>14<\/sup>C sodium bicarbonate stock solution (MP Biomedicals<\/span>, LLC)<\/o:p><\/sup><\/p>\n

\n\t\u00b7         <\/span><\/span><\/span>Millipore Type HA filters (Fisher Scientific)<\/p>\n

\n\t\u00b7         <\/span><\/span><\/span>vacuum filtration system including separate device for DOC filtrate capture<\/p>\n

\n\t\u00b7         <\/span><\/span><\/span>Polycarbonate centrifuge bottles<\/p>\n

\n\t\u00b7         <\/span><\/span><\/span>Teflon laboratory wares<\/p>\n

\n\t\u00b7         <\/span><\/span><\/span>vortex mixer<\/p>\n

\n\t\u00b7         <\/span><\/span><\/span>liquid<\/span> scintillation counter (LS 6000LC Beckman Instruments, Inc.)<\/p>\n

\n\t11. Reagents<\/span><\/h3>\n

\n\t\u00b7         <\/span><\/span><\/span>Milli<\/span>-Q filtration\/anion exchange water purifier<\/p>\n

\n\t\u00b7         <\/span><\/span><\/span>Micro-90 Cleaning solution, Cole Palmer Instrument Co.<\/span><\/p>\n

\n\t\u00b7         <\/span><\/span><\/span>HCl<\/span> for trace metal analysis (Fisher Chemical)<\/p>\n

\n\t\u00b7         <\/span><\/span><\/span>Na2<\/sub>CO3<\/sub> (99.995%) Aldrich Chemical<\/p>\n

\n\t\u00b7         <\/span><\/span><\/span>NaH-14<\/sup>CO3<\/sub> solution (cat #17441H MP Biomedicals<\/span>, LLC.)<\/p>\n

\n\t\u00b7         <\/span><\/span><\/span>2-amino ethanol (ethanolamine)  <\/span>ACS grade<\/p>\n

\n\t\u00b7         <\/span><\/span><\/span>Aquasol<\/span>-II (Dupont<\/span>)<\/p>\n

\n\t\u00b7         <\/span><\/span><\/span>Ecolume<\/span> (MP Biomedicals<\/span>, LLC.)<\/p>\n

\n\t <\/o:p><\/p>\n

\n\t12. Re-count check<\/span><\/h3>\n
\n\t14<\/sup>C scintillation counts were checked for accuracy by re-counting an entire cruise (n>200) of vials 9 months after original counting.  Depletion due to half life was ignored due to the long half life of 14<\/sup>C.  Results for samples greater than 1000dpms were averaged resulting in a return of counts equal to 101.3%.  Efficiencies had a similar recount statistic of 100.9%.  The exercise lead to evaluating cruise counts where the source of some replicate inconsistency was the result of chemiluminescence problems in which the counter displays a “lumex %”. It is important to monitor for higher lumex numbers which result in elevated counts due to a chemiluminescent reaction. Samples were dark adapted and recounted resulting in much better replicates.<\/div>\n

\n\t13. References<\/span><\/h3>\n

\n\t <\/o:p><\/p>\n

\n\t\u00b7         <\/span><\/span><\/span>Fitzwater, S. E., G. A. Knauer<\/span> and J. H. Martin, 1982.  <\/span>Metal contamination and its effect on primary production measurements.  <\/span>Limnol<\/i><\/span>. Oceanogr<\/span><\/span><\/i>.,<\/span> 27<\/i>: 544-551.<\/p>\n

\n\t\u00b7         <\/span><\/span><\/span>Lean, D. R. S. and B. K. Burnison, 1979.  <\/span>An evaluation of errors in the 14<\/span>C method of primary production measurement.  <\/span>Limnol<\/i><\/span>. Oceanogr<\/span><\/span>.,<\/span> 24<\/i>: 917-928.<\/p>\n

\n\t\u00b7         <\/span><\/span><\/span>Steeman<\/span>-Nielsen, E. (1951). “Measurement of production of organic matter in sea by means of carbon-14”. Nature 267: 684\u2013685.<\/p>\n

\n\t\u00b7         <\/span><\/span><\/span>Strickland, J. D. H. and Parsons, T. R. 1968.  <\/span>A Practical Handbook of Seawater Analysis pp. 267-278.<\/p>\n

\n\t <\/o:p><\/p>\n","protected":false},"excerpt":{"rendered":"

PRIMARY PRODUCTIVITY   OVERVIEW: Primary production is estimated from 14C uptake using a simulated in situ technique in which the assimilation of dissolved inorganic carbon by phytoplankton yields a measure of the rate of photosynthetic primary production in the euphotic zone.   1. Principle Seawater samples are incubated with a radioactive substrate to determine the […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[19],"tags":[],"class_list":["post-324","post","type-post","status-publish","format-standard","hentry","category-methods"],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/mindwander.com\/index.php\/wp-json\/wp\/v2\/posts\/324","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/mindwander.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/mindwander.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/mindwander.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/mindwander.com\/index.php\/wp-json\/wp\/v2\/comments?post=324"}],"version-history":[{"count":0,"href":"https:\/\/mindwander.com\/index.php\/wp-json\/wp\/v2\/posts\/324\/revisions"}],"wp:attachment":[{"href":"https:\/\/mindwander.com\/index.php\/wp-json\/wp\/v2\/media?parent=324"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/mindwander.com\/index.php\/wp-json\/wp\/v2\/categories?post=324"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/mindwander.com\/index.php\/wp-json\/wp\/v2\/tags?post=324"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}