This powerpoint presentation begins by providing a brief overview of the Colorado River Aqueduct system in southern California, and the significant threat of quagga mussels to the lower Colorado River system. The objectives of this 2-yr study on the 4 reservoirs of
the Colorado River Aqueduct were to: improve understanding of veliger distribution within
the reservoirs of the Colorado River Aqueduct;
identify the limnological factors governing veliger
abundance, distribution and fate; and,
develop in-lake control strategies to minimize their
spread and limit their impacts to reservoirs,
conveyances and other infrastructure. Approach methodology included: in situ measurement of water column properties
using Hydrolab Surveyor and DataSonde4a;
plankton tows using a Wisconsin closing net for
zooplankton and veliger abundance and distribution; and,
veliger enumeration and size distribution using cross-polarized
light on a Nikon E600 compound scope
fitted with a micrometer; water samples were collected using a Kemmerer sampler
near the center of the epilimnion, thermocline and
hypolimnion;
chlorophyll a and dissolved and total nutrient
concentrations determined on samples;
hydroacoustic measurements of sediment properties,
fishery and zooplankton using a BioSonics DTX
echosounder with 200-kHz split beam transducer; and,
water current velocities determined using drogues
fitted with GPS loggers and with an RDI 600-kHz
Workhorse Sentinel ADCP. Seasonal trends and spatial trends are presented. Includes figures.
| Edition : | Vol. - No. |
| File Size : | 1
file
, 1.5 MB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 24 |
| Published : | 11/01/2009 |
