Samples were collected in a perimeter of ~1 km offshore of the discharge channel of Carlsbad Desalination Plant, Carlsbad Beach, California (33°08'18.9"N 117°20'21.3"W).
Samples were collected in four trips:
Pre-discharge: Dec 2nd-4th 2014 and Sep 21st-24th 2015.
Post-discharge: May 9th-12th 2016 and Nov 8th-11th 2016
Transect lines were deployed going from the discharge channel (Outflow) and the Intake to 1000 m offshore. Sampling was done every 25 m until 200 m offshore, then at 400, 600, 800 and 1000 m (“stations”). The "Parallel" transect ran continuous parallel to the beach ~200 m offshore and samples stations were deployed every ~100 m. Station 1 is the southern-most sampling point (south of discharge channel). At each station surface (~1 m depth) and bottom water samples were taken and a sediment sample. Bottom samples were collected at a depth range of 4m - 17m.
The benthic surveys were done continuously at the first 200 m offshore if water conditions allowed. At station 400, 600, 800 and 1000 and on the parallel stations, ten 1x1m quadrates were deployed.
Sediment analysis: 300-500 g of sediment was collected at certain stations. The sediment was kept at -20 degrees C. Upon analysis, the sediment was thawed and rinsed in 90% ethanol.
The ethanol was obtained and surveyed through a microscope to count the organisms present. The counted individuals were summed and normalized to the weight of the sample.
The sediment was dried and weighed and the grain size analyzed through sieving.
BCO-DMO Blog
©2024 Biological and Chemical Oceanography Data Management Office.
