rotula by Stephanie Anderson
surface, bottom and net tow samples are collected
from Station II in Narragansett Bay, RI (lat. 41
34.2N; long. 71 23.4W). Previously, equal volumes
of surface and bottom water were combined for counting. Currently,
surface and bottom water are
counted separately (count type indicated with
data). Phytoplankton cells are enumerated under a
compound microscope using a Sedgewick-Rafter
counting chamber. Samples are counted live and
unconcentrated. A 20μm net tow sample is
species observed in the net sample are
recorded as present but not counted. Species
identifications are based on appearance in the
Sedgewick-Rafter chamber and supplemented with
permanent mounts examined with phase contrast and
interference contrast optics. Samples are
preserved in 1% Lugol's preservative. The accurate
identification of very small and problematic
species is not guaranteed. Quality control
of all counts in the database has been conducted
on samples collected between
1999 and 2008 and includes analysis of changes in community composition (Windecker, 2010).
Cell count data spreadsheets are available
(Microsoft Excel; units = cells per liter). The
available data start in January 1999. See
Historical Data (below) for earlier data.
Acartia tonsa & various phytoplankton by Anna Mosby and Caitlyn Lawrence
Weekly vertical net
tows are taken from 5 m to surface with a ¼ m
diameter, 64μm mesh net from the
same station at which phytoplankton are collected.
The volume filtered is 0.25 m3.
The sample is preserved immediately in a final
concentration of 4% buffered formalin-seawater
solution. Zooplankton are identified and
enumerated under a dissecting microscope from a
subsample taken with a wide bore pipette
calibrated in mls. The subsample volume is chosen
to ensure counting of at least 200 organisms.
Species identification is made for all copepodite
stages of copepods. Copepod nauplii are lumped. Other
taxa are identified to species when known, or if
not (as for benthic larvae) to order.
Gelatinous species are collected with a separate
vertical tow taken with a ½ m diameter 1 mm mesh
net with a flowmeter. Sample volume is 1.1 m3.
This sample is returned to the laboratory and live
organisms are counted immediately to ensure that
ctenophores, which do not withstand preservation,
can be accurately enumerated. Diameter of medusae
and ctenophores are measured and all are
identified to species. Drained volume of the
sample is recorded. Sampling began in 1999 but
samples were stored and only those from October
2001 to the present have been counted with funding
from the National Science Foundation and the
Vetleson Foundation Grants to Barbara K. Sullivan.
Zooplankton and data gelatinous zooplankton spreadsheets are available for download (Microsoft Excel). The available data start in October 2001.
Lachat Nutrient Analyzer
Environmental parameters measured include secchi-disk depth, temperature, salinity and nutrient concentrations. Physical data spreadsheets (including secchi-disk depth, temperature and salinity) are available for download (Microsoft Excel). The available data begin in 1999. Water column profiles of temperature, salinity, depth, pH, dissolved oxygen and chlorophyll fluorescence are also recorded. Please e-mail if you are interested in obtaining water column profile data. Nutrient concentrations are measured in surface and bottom samples. Samples are collected, kept on ice and filtered within a few hours of collection. Filtering is done with an acid washed filtration manifold (60 ml syringe and Millipore filtering tips) using 0.45 mm cellulose filtering membranes. Filtrate is placed in 60 ml polyethelene bottles and frozen at -20ºC until analysis. For further information on nutrient analysis please see our methods summary.
Nutrient data spreadsheets are available for download (Microsoft Excel). The available data begin in 2003.
Nutrient analysis was
conducted through support from RI Sea Grant from