10/21/23 Morning Trip

Reservation Point | San Pedro Canyon | Relict Beach | Biodredge | Otter Trawl

Station 1: Reservation Point

Date: 10/21/2023, 8:30 AM
Conditions: 64°F, sunny, no clouds, light wind (ENE 5)
Latitude: 33° 43' 14" N
Longitude: 118° 15' 45" W

Bottom depth (m): 25.2 
Forel Ule Color: III
Secchi Disk (m): 4.5

Depth
Electrical Salinity ‰
Dissolved
O2 mL/L
Acidity (pH)
Temp ºC
1 33.16 7.52 n/a 17.8
5  33.14 7.33 n/a 17.5
10 33.19 7.23 n/a 17.0
15 33.19 7.19 n/a 16.0
20 33.19 7.7 n/a 15.2

 

Sediment Description

The sediment in this part of the Los Angeles Harbor is typical of that found over most of the San Pedro Shelf - a grey-green silty to clayey micaceous mud. This sediment was derived from land, brought to the harbor via the Los Angeles river, storm drains, and general run-off. Coarser particles like sand settled near the shore, while silts and clays drifted out to the quiet waters of the shelf.

But why is it green? The harbor waters are warm and nutrient-rich, allowing algae and phytoplankton to thrive, and tinting the mud green.


Gray-green slity clay from station 1Sediment Desc: Green-grey clay-rich silty clay.
Flora & Fauna: worm tube, 2 brittle stars, 1 broken bivalve shell
Lithogenous: 100%
Biogenesis: 0%
Consolidated? No
Oxidized? Yes

 

 

 

 

 

 

 



Station 2: San Pedro Canyon


Date: 10/21/2023, 9:06:00 AM
Conditions: 67°F, sunny, no clouds, light wind (ENE 6 mph)
Latitude: 33° 40' 45"
Longitude: 118° 17' 47" W

Bottom depth (m): 46 
Forel Ule Color: I
Secchi Disk (m): 20.0


Depth
Electrical Salinity ‰
Dissolved
O2 mL/L
Acidity (pH)
Temp ºC
1 33.34 8.09 n/a  18.8
5 33.35 8.21 n/a 18.8
10 33.32 8.35 n/a 18.0
15 33.25 8.54 n/a 17.0
20 33.23 8.49 n/a 16.5


Sediment Description: station not done
% lithogenous: n/a
% biogeneous: n/a
Consolidated? n/a
Oxidized? n/a




Station 3: Relict Beach

Date: 10/21/2023, 10:14 AM
Conditions: 68°F, sunny, no clouds, light wind (ENE 7 mph)
Latitude: 33° 40' 44" N
Longitude: 118° 12' 25" W

Bottom depth (m): 22
Forel Ule Color: I
Secchi Disk (m): 14.5

Depth
Electrical Salinity ‰
Dissolved
O2 ml/l
Acidity (pH)
Temp ºC
1 33.32 8.27 n/a 18.2
5  33.31 8.30 n/a 18.0
10 33.31 8.37 n/a 17.4
15 33.27 8.53 n/a 16.4
20 33.23 8.54 n/a 14.6

Orange-brown medium sand from Station 3
Sediment Desc: orange brown medium sand
Flora & Fauna: shell fragments, sand flea
% lithogenous: 80
% biogeneous: 20
Consolidated? no
Oxidized? yes