Bight'98 Chemistry Data

Metadata:

• Identification_Information
• Data_Quality_Information
• Spatial_Data_Organization_Information
• Spatial_Reference_Information
• Entity_and_Attribute_Information
• Distribution_Information
• Metadata_Reference_Information

Identification_Information:

Citation:

Citation_Information:

Originator:

Southern California Coastal Water Research Project (SCCWRP)

Publication_Date: 20021221

Title: Bight'98 Chemistry Data

Edition: Version 1

Publication_Information:

Publication_Place: Costa Mesa, CA

Publisher: SCCWRP

Online_Linkage: View a Map of this Data [html]

Download this Data as an Excel Friendly File [csv]

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Description:

Abstract:

Sediment samples from 361 sites on the continental shelf between Point Conception, California, and Ensenada, Mexico were collected between July 13 and September 16, 1998. The sites were selected using a stratified random design, and of these 290 sites were in the U.S., and 71 sites were in Mexico off the coast of Baja California. For the 290 U.S. stations, five of the strata were located offshore (river mouths, large publicly owned treatment works [POTW] discharge areas, small POTW discharge areas, remaining shallow areas [5-30 m], and remaining mid-depth areas [30-120 m]). Three additional strata were located within bays and harbors, which included marinas, ports/industrial areas, and other bay and harbor areas. Another strata was chosen for temporal comparisons. A set of thirteen historical stations were chosen because of their coincidence with previous surveys, and the availability of data going back to 1977. The Subsets of the 290 U.S. sediment samples were analyzed for grain size, mineralogy, total nitrogen, TOC, 15 metals, and 5 classes of organic contaminants. In addition, sediments were analyzed for acid volatile sulfide (AVS), simultaneously extracted metals (SEM), and metals in the sediment interstitial water. Nine different laboratories participated in various portions of the chemical and physical analyses for this study. The target metal analytes for the 290 U.S. stations were aluminum, antimony, arsenic, beryllium, cadmium, chromium, copper, iron, lead, mercury, nickel, selenium, silver, zinc. The target organic analytes were chlordanes (a + g), Total DDT's (6 isomers - o,p-DDT,DDD, DDE and p,p-DDT,DDD,DDE), 42 polychlorinated biphenyl (PCB) congeners, 24 polynuclear aromatic hydrocarbons (PAHs), and C10 - C14 linear alkylbenzenes (LABs). In addition to sediment samples, 275 composite demersal fish tissue samples representing 226 sites were analyzed for chlordanes, DDTs and PCBs. There are corresponding sediment chemistry data for 147 composite samples representing 132 sites. The sediment samples from Mexico were analyzed for a smaller suite of contaminants, excluding TOC, TN, antimony, arsenic, barium, mercury, selenium. Sediments were evaluated by using area weighted means, medians, and confidence intervals on a strata basis. Stations and bight area above background were determined using an iron normalization approach. Relationships in the types and concentration of contaminants among the stations was studied using principle component analysis (PCA). The concentration of organic pollutants in the sediments was compared to the response from a P450 human reporter gene system (P450 HRGS) bioassay, new EPA Method 4425, to evaluate its effectiveness as a screening tool for contaminated sediments. An assessment of the percent of the Southern California Bight (SCB) impacted by anthropogenic pollution was made using a combination of the ERM quotient and the equilibrium partitioning approaches.

Purpose:

The purpose of the sediment chemistry component of the Bight '98 regional monitoring project is to: 1) Estimate the nature, extent, and magnitude of chemical contamination within the SCB; 2) Compare the sediment chemical contamination among different geographic regions and among different use and/or source areas; 3) Assess the potential for biological impacts as a result of the measured levels of contaminants in the sediments; and 4) Determine the temporal changes in the concentrations and assemblages of chemical contaminants in surface sediments at selected sites over a twenty-one year period from 1977 to 1998.

Supplemental_Information:

GRAB SAMPLER - A 0.1 m2 modified Van Veen grab sampler was used to collect sediment samples for physical, chemical, and infaunal analysis (Stubbs et al. 1987). This device is manufactured by Kahl Scientific Instrument Corporation, 737 West Main Street, El Cajon, California 92022 (619/444-2158). The grab sampler may be galvanized, stainless steel, or Teflon-coated. All surfaces of the grab must be clean and free of rust. Either single or tandem Van Veen grabs are acceptable. GRAB SAMPLING PROCEDURES - Prior to deployment, the grab is cocked with the safety key in place. The grab is then hoisted over the side, the safety key is removed, the grab is lowered at 2 m/sec until it is 5 m above the bottom where it is then lowered at 1 m/sec to minimize the effects of bow wave disturbance of the surface sediment. After bottom contact has been made (indicated by slack in the winch wire), the tension on the wire is slowly increased, causing the lever arms to close the grab. Once the grab is back on board, the top doors are opened for inspection. The first grab collected at a site should be used for the benthic infaunal sample. The chemistry and sediment toxicity samples will be collected from subsequent grabs. Different sediment types (e.g. cobble, gravel, well sorted sands) and localities (e.g., canyons, slopes, rocky areas) may be difficult to sample. Sediments containing rocks create the most common problem by preventing complete closure of the grab by allowing sediment to wash out during retrieval. Some of the Bight'98 sampling sites may occur on these difficult sediment types or localities because of the randomized sampling design. Therefore, if after three unsuccessful attempts at a site and up to three more unsuccessful attempts at each of two other locations (within 100 m distance from and ±10% of the depth of the nominal site), the station should be abandoned. CRITERIA FOR ACCEPTABLE GRAB SAMPLES - Upon retrieval of the grab the acceptability of the sample must be determined. Acceptability is based upon two characteristics of the sample: sample condition, and depth of penetration. Sample condition is judged using criteria for surface disturbance, leakage, canting, and washing. An acceptable sample condition is characterized by an even surface with minimal disturbance and little or no leakage of the overlying water. Heavily canted samples are unacceptable. Samples with a large amount of "humping" along the midline of the grab indicating washing of the sample during retrieval are also unacceptable. While some humping will be evident in samples from firm bottoms where penetration hasbeen poor, this is due to the closing action of the grab and is not evidence of unacceptable washing. If the sample condition is acceptable, the overlying water is drained off and the depth of penetration determined by insertion of a plastic (rather than metal) ruler vertically along the grab midline and measuring to the nearest 0.5 cm. Sediment penetration depth must be at least 5 cm: however, penetration depths of 7-10 cm should be obtained in silt (fine sand to clay). Extra caution should be taken to drain the overlying water from the grabs for chemistry and toxicity samples. It is recommended that a siphon be employed for these grabs to avoid disturbance and loss of the surface sediments. The overlying water in grabs intended for infaunal samples may be drained by slightly opening the jaws of the grab and allowing the water to run off, as long as all drained water is captured for screening with the sediments (see Sample Processing below). If both sample condition and penetration are acceptable, sampling at the station proceeds with the collection of chemistry and sediment toxicity samples from successive grabs. It is required that all of the grabs taken at a station be of similar sediment type and depth of penetration. If only one sample of a series of grab attempts is usable, the sediment sample should be kept for infaunal analysis. BENTHIC DATA SHEET - The Chief Scientist is responsible for the proper completion of the Benthic Data Sheet for each station. The information recorded on this sheet includes date time of sampling, weather and sea state, navigational position, and other information applicable to the sampling site. For each sample collected (i.e. infaunal, chemistry, toxicity), sampling failures, grab penetration depth, sediment description (type, color, and odor), vessel location, and other sample handling information are to be recorded. SEDIMENT CHARACTERIZATION - The field description of sediments is required following measurement of penetration depth. The sediment should be characterized as being coarse sand, fine sand, silt or clay, gravel, or of a mixed type. The presence of petroleum tar and shell hash should also be recorded. Obvious odors, such as hydrogen sulfide (the odor of rotten eggs), petroleum, other odors, or a lack of noticeable odors should be recorded. General sediment colors (i.e., black, green, brown, red, olive, or gray) should also be recorded. SAMPLE COLLECTION AND STORAGE - Samples for the various analyses were collected from the top 2 cm of the grab and at least 1 cm away from the metal sides of the sampling device. An appropriate amount of sample was collected using a Teflon-coated metal or plastic scoop and into a pre-cleaned container supplied by the laboratories performing the respective analyses. After collection samples were stored on ice or in a refrigerator at 4° C until returned to the laboratory. Samples for AVS-SEM, grain size, and mineralogy, were kept at 4° C until analyzed (i.e., not frozen). Samples for TOC, TN, trace metals and trace organics were kept frozen at -20°C until analyzed. SAMPLE PREPARATION - Samples for trace metal analysis were digested using a strong acid digestion following protocols specified in EPA methods 3055, 3050A and 3050B. Samples for trace for organic analysis were extracted by one of following methods: Accelerated solvent extraction (ASE), microwave assisted solvent extraction (MASE), roller table solvent extraction, and soxhlet extraction. For the fish tissue samples, the whole fish composite samples were placed in a blender with an equal mass of water and pureed until well homogenized. The whole fish puree was then solvent extracted. The data reported for the fish tissues in the database have already been adjusted for dilution, and reflect the calculated whole fish concentration. Each participating laboratory employed their own clean-up methods as appropriate for the suite of analytes being measured. ANALYTICAL METHODS - Sediment grain size distributions were measured using a laser diffraction technique on one of two instruments, a Horiba LA900 and a Coulter LS230, which measure 74 (0.05 -1019 mm) and 116 (0.04 - 2000 mm) size classes, respectively. TOC and TN were measured using a Carlo Erba 1108 Elemental Analyzer. The clay mineral content of samples was measured using x-ray diffraction, and non-clay mineral content of the samples was measured by optical microscopy. Trace metals were analyzed by one of the following methods as appropriate for the respective metal: Inductively coupled plasma atomic emission spectroscopy (ICP-AES), inductively coupled plasma mass spectrometry (ICP-MS), flame atomic absorption spectroscopy (FAA), graphite furnace atomic absorption spectroscopy (GFAA), hydride generation atomic absorption spectroscopy (HAA), or cold vapor atomic absorption spectroscopy (CVAA). Chlorinated organics (chlordanes, DDTs and PCBs) were analyzed by capillary gas chromatography with either electron capture detection (GC-ECD) or mass selective detection (GC-MS). The PAHs and LABs were analyzed by GC-MS. PREFERRED ANALYSIS METHODS: The station locations in this study were selected using a stratified random sampling design. Therefore the results from each individual station should be viewed in light of their associated area weight. This is necessary when ever spatial comparisons are made by extrapolation of individual station data. USAGE: There are few restrictions on the use of these data. For metals only the data for antimony is somewhat questionable as it frequently exceeded data quality objectives. For the trace organic data it should be noted that there are many data reported below the specified reporting limit, and some data values are also below the nominal minimum detection limit (MDL). The actual results obtained in trace organic analyses are a function of the analytes, the matrix and analytical methods employed. It was agreed upon by the participating laboratories that if they had results that were below the nominal MDL, but clearly above the background noise and identified as target analytes, they would make an effort to estimate the concentration. It was felt that an estimated concentration was better than reporting these clear analyte "hits" as non-detect, or applying some arbitrary convention such as half the MDL. As with all trace analytical data, results close to MDL have a greater degree of uncertainty as compared to data that are well above the MDL. Missing numerical values have been coded as -99 Missing text values have been coded as NR Missing date values have been coded as 01/Jan/1998 Missing time values have been coded as 23:00

Time_Period_of_Content:

Time_Period_Information:

Range_of_Dates/Times:

Beginning_Date: 19980312

Ending_Date: 20001208

Currentness_Reference: ground condition

Status:

Progress: Complete

Maintenance_and_Update_Frequency: None planned

Spatial_Domain:

Description_of_Geographic_Extent: Southern California Bight

Bounding_Coordinates:

West_Bounding_Coordinate: -120.49462

East_Bounding_Coordinate: -116.6375

North_Bounding_Coordinate: 34.459

South_Bounding_Coordinate: 31.7511

Keywords:

Theme:

Theme_Keyword_Thesaurus: None

Theme_Keyword: Sediment Chemistry

Theme_Keyword: Tissue Chemistry

Theme_Keyword: Interstitial Water

Theme_Keyword: Acid Volitile Sulfides

Theme_Keyword: Metals

Theme_Keyword: Organics

Theme_Keyword: MASE

Theme_Keyword: Soxhlet

Theme_Keyword: Roller

Theme_Keyword: Tissue

Theme_Keyword: EPA 3055

Theme_Keyword: EPA 3055A

Theme_Keyword: EPA 3050B

Theme_Keyword: ASE

Theme_Keyword: Priority Pollutants

Theme_Keyword: Pesticides

Theme_Keyword: PAH

Theme_Keyword: PCB

Access_Constraints: None

Use_Constraints: Dataset credit required

Point_of_Contact:

Contact_Information:

Contact_Person_Primary:

Contact_Person: Eddy Zeng

Contact_Organization:

Southern California Coastal Water Research
Project(SCCWRP)

Contact_Position: Scientist

Contact_Address:

Address_Type: mailing address

Address: 3535 Harbor Blvd., Suite 110

City: Costa Mesa

State_or_Province: California

Postal_Code: 92626

Country: USA

Contact_Voice_Telephone: 714.755.3200

Contact_Facsimile_Telephone: (714.438.1016

Contact_Electronic_Mail_Address: eddyz@sccwrp.org

Hours_of_Service: 8:00 a.m. to 4:00 p.m. Monday Through Friday

Contact_Instructions: E-mail preferred

Data_Set_Credit: SCCWRP

Native_Data_Set_Environment: Microsoft Access Version 97

Cross_Reference:

Citation_Information:

Originator:

Southern California Coastal Water Research Project (SCCWRP)

Publication_Date: 20021221

Title: Bight'98 Survey

Edition: Version 1

Publication_Information:

Publication_Place: Costa Mesa, California

Publisher: SCCWRP

Online_Linkage: http://www.sccwrp.org/data/1998_bight_survey.html