charge of water 35 feet below. Figure 8 is a close-up aerial photograph
of the boat basin. Two stations within the basin (100 and 400) and one
offshore of the entrance channel (mid) were selected for pre-project and
post-project monitoring. In 1980, Larsen and Associates measured dis-
solved oxygen levels, salinity and temperature (thereby deriving water
density) at depths from surface to bottom at these three stations.
Since that time, and during the monitoring program, they are measuring:
1.   Dissolved oxygen, temperature and salinity within one hour
of sunrise at 2 foot depth intervals, surface to bottom at
the two stations within the boat basin and one offshore.
They note the presence or absence of hydrogen sulfide in
benthic samples. Quantitative benthic samples, in duplicate,
have been obtained at all three stations monthly.
2.   Water movement through the culvert system over one tidal
cycle is measured monthly by recording flow meter.
3.   There was one pre-project and will be quarterly post-
project measurements of total phosphates, nitrogen and
organic carbon from the same three stations at surface
and near the bottom.
4.   There will be a one-time dye study of water circulation
patterns in the basin on in and outgoing tide.
Figure 9 shows dissolved oxygen measurements obtained in 1980 at
various depths in this boat basin. These data are the averages of the
two interior stations at any one time. It is readily seen that in
November of 1980, the basin was distinctly stratified, and dissolved
oxygen was absent below 15 feet. In early December, the basin destrati-
fied and oxygen was present all the way to the bottom. Later in


47