<pre>
<b>PI:</b> David Garrison and Marcia Gowing
<b>dataset:</b> Mesopelagic microplankton abundance and carbon biomass
<b>project/cruise:</b> Arabian Sea/TTN-054 - Process Cruise 7
<b>ship:</b> Thomas Thompson
<H2>Mesopelagic microplankton Methodology: 11 August 2004</H2>
<pre>
Water samples were collected from 250 to 1000 or 1100 m depth. On cruises
TTN043 and TTN045 aliquots totaling 4-9 liters per depth were taken from
two 10 liter Niskin bottles. On cruises TTN050 and TTN054, entire contents
(42-59 liters) of six 10 liter Niskin bottles per depth were used. Organisms
were then concentrated within ~ 225 ml by the reverse filtration technique
(Dodson and Thomas 1978) with 20 micrometer pore sized NitexTM mesh.
Concentrated samples were measured and preserved in glass jars with a solution
of 20% paraformaldehyde in 5% sodium borate to give a final concentration of
2% paraformaldehyde. Entire samples were settled in the dark at 4 degrees °C
in chambers to which a drop of a 1 mg per ml aqueous solution of DAPI
(Coleman 1980) had been added. Entire chambers were examined at 150X using an
epifluorescence microscope and a combination of tungsten and UV light.
Microplankton (predominantly organisms 20-200 micrometers but sometimes larger)
with a stained nucleus were counted and measured. Biomass was estimated by
converting cell volumes to carbon using conversion factors for the various
groups as described by Gowing et al. (2003).</pre>
References:
Coleman, A.W. 1980. Enhances staining of bacteria in natural environments by
fluorochrome staining of DNA. Limnol. Oceanogr. 25:948-951.
Dodson, A.N., W.H. Thomas. 1978. Reverse filtration. In: Sournia, A. (ed),
Phytoplankton Manual. UNESCO, Paris, pp. 104-122.
Gowing, M.M., D.L. Garrison, K.F. Wishner, C. Gelfman. 2003. Mesopelagic
microplankton of the Arabian Sea. Deep-Sea Res. I. 50:1205-1234.
<H3>PI note regarding multi-bottle sampling</H3>
Note: _gt20 in the parameter names indicates organisms predominantly
20-200 micrometers but sometimes larger in size.
</pre>