X-Sender: egoetze@insci14.ucsd.edu
Date: Tue, 20 Nov 2001 11:11:30 -0800
To: shipsked@ucsd.edu
From: Erica Goetze <egoetze@ucsd.edu>
Subject: Cruise Plan - R/V Roger Revelle, Dec 16 - Jan 2, 2002
Cc: leastman@ucsd.edu, Colomban de Vargas <cvargas@oeb.harvard.edu>,
"James A. Schmitt" <jschmitt@ucsd.edu>
Cruise Plan - R/V Roger Revelle, Dec 16 - Jan 2, 2002. Easter Island -
Lyttleton, New Zealand
Project Title: Speciation in the Open Ocean: the Importance of Transition
Zones in Population Differentiation in the Copepod Family Eucalanidae
This project examines the Eucalanidae, a family of oceanic planktonic
copepods, as a model system to elucidate the mechanisms that play a role in
speciation in planktonic environments. Transition zones between
subtropical and subantarctic water masses often contain endemic species of
planktonic organisms or disjunct populations of more broadly distributed
species, and may be important oceanographic regions for incipient
speciation. On this cruise we will sample the plankton communities of the
South Pacific subtropical gyre, and the South Pacific transition zone. The
specimens obtained during this transit leg will be a major portion of
specimens obtained for a global phylogeographic study of speciation in this
copepod family. Samples will also be collected for a population genetic
study of planktonic foraminifera, as well as for global studies of the
importance of bacteriochlorophyl a in the mixed layer.
Of the 2 science days budgeted for the transit leg, ~ 0.3 days will be used
for CTD casts to 500m, and the remaining time will be used to collect
vertically integrated plankton samples from the upper 800m of the water
column. Paired bongo nets of 150 and 333 µm mesh will be used for sample
collection. Sampling time will allow for 25-28 plankton tows to be
collected during the cruise, with a CTD cast every other day, to be
deployed just prior to a plankton tow. Plankton tows will occur nightly
1.5 - 2 hours after sunset, and a second tow will be done daily in the
early-mid morning, as time allows. The exact location of the plankton tow
locations may be modified as we monitor underway oceanographic data.
During CTD casts, Niskin bottles will collect water samples at 6-8 depths
targeted to sample throughout the mixed layer and chlorophyl maximum, in
order to estimate chlorophyl a and bacteriochlorophyl a concentrations.
We would also like to coordinate any XBT drops done to determine sound
velocity for underway Seabeam data with the plankton sampling, as this
additional data could be quite useful for our purposes as well. Dropping
an XBT just prior to arrival or just as we are leaving station would be
ideal. We will also collect underway ADCP data for information regarding
plankton patchiness during the transit leg.
Personnel: Erica Goetze (SIO, graduate student), Dr. Colomban De Vargas
(Harvard Univ. and WHOI, post-doctoral researcher), Grzegorz Dziadurski
(volunteer assistant), Jim Schmitt (STS-ODF)