National Status and Trends: Bioeffects Program - Kachemak Bay Database

This study was based on the sediment quality triad (SQT) approach. A stratified probabilistic sampling design was utilized to characterize the Kachemak Bay system in terms of chemical contamination, sediment toxicity and benthic infaunal community structure. The purpose was to define the extent and magnitude of toxicity and other biological effects associated with contaminants in the Kachemak Bay system. Five strata (Homer harbor, Western intertidal, Western subtidal, Eastern intertidal, and Eastern subtidal) were established in the shallow (less than 10 fathoms) northern area of the bay. Sediment samples were collected at multiple stations in each strata. A broad suite of sediment contaminants were analyzed at each station, including polynuclear aromatic hydrocarbons (PAHs), chlorinated pesticides including DDT and its metabolites, polychlorinated biphenyls (PCBs), trace elements, and butyl-tins Other parameters included grain size analysis, total organic/inorganic carbon (TOC/TIC), and percent solids. Characterization of infaunal assemblages and the abundance of organisms present in sediments provide additional information to help determine areas of degraded sediments. Whole sediment toxicity bioassays with two species of amphipod were conducted to test for overt contaminant toxicity. This project provides invaluable baseline data on sediment infauna species richness, chemical contamination and toxicity that is georeferenced and posted on the internet through the NOAA's National Status and Trends data portal.

Specific objectives of the study were to: 1. Describe the concentrations and spatial distribution of contaminants in the Kachemak Bay estuary; 2. Characterize benthic macroinvertebrate community in terms of species richness, abundance, and characteristics of the benthic infaunal community in Kachemak Bay; 3. Describe the incidence, severity and spatial extent of toxicity in Kachemak Bay; 4. Describe the study results in relation to known or suspected sources of contamination; 5. Describe statistical relationships between levels of contaminants and adverse biological effects, and identify chemicals of concern in terms of regional environmental quality and adverse biological effects; 6. Compare environmental conditions within sub-areas of Kachemak Bay and compare estimates of toxicity in Kachemak Bay with those in other estuaries based on comparable data. The dataset objective is to report information about chemical residues in sediment, sediment toxicity, and benthic infauna characteristics of the system.

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PRINCIPAL INVESTIGATORS - S. Ian Hartwell, NOAA Ocean Service, National Status and Trends Program; Dennis Apeti, NOAA Ocean Service, National Status and Trends Program; Kimani Kimbrough, NOAA Ocean Service, National Status and Trends Program; W. Edward Johnson, NOAA Ocean Service, National Status and Trends Program; SAMPLE COLLECTION INVESTIGATORS - Ian Hartwell, NOAA Ocean Service, National Status and Trends Program; Kimani Kimbrough, NOAA Ocean Service, National Status and Trends Program; W. Edward Johnson, NOAA Ocean Service, National Status and Trends Program; SAMPLE PROCESSING INVESTIGATORS - Contaminant analyses: Organic and inorganic chemicals in sediment: TDI Brooks Inc., College Station, TX SAMPLE PROCESSING INVESTIGATORS - Sediment physico-characteristics Grain size and total organic content: TDI Brooks Inc., College Station, TX SAMPLE PROCESSING INVESTIGATORS - Benthos taxonomy: Allan Fukuyama, FHT Environmental, Edmonds, WA. 98026 SAMPLE PROCESSING INVESTIGATORS - Toxicity and Bioassays: Dan Johnson, TRAC Laboratories, Inc. Pensacola, FL. 32507

The dataset is composed of three relational files each listed below. The "SITES" data file reports information regarding the planned sampling locations and the actual locations. The geographical information provided for a sampling site (the estuary stratum and site) is useful when interpreting the results of other data files. Link for the SITES data http://ccma.nos.noaa.gov/about/coast/nsandt/download.aspx The "FIELD" data file reports measurements made in the field while on station. This includes water column data such as temperature, salinity, dissolved oxygen, and specific conductance. Link for the FIELD data dictionary http://ccma.nos.noaa.gov/about/coast/nsandt/download.aspx The "INDICATOR" data file reports the results of analyses for chemical/microbial analytes, sediment toxicity bioassays and biomarkers, and benthic community indices. Link for the INDICATOR data dictionary http://ccma.nos.noaa.gov/about/coast/nsandt/download.aspx

NOAA National Status and Trends Program

These data were prepared by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, make any warranty, expressed or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed in this report, or represents that its use would not infringe privately owned rights. Reference therein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. Any views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof. Although all data have been used by NOAA, no warranty, expressed or implied, is made by NOAA as to the accuracy of the data and/or related materials. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by NOAA in the use of these data or related materials.

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NOAA requests that all individuals who download NOAA data acknowledge the source of these data in any reports, papers, or presentations. If you publish these data, please include a statement similar to: "Some or all of the data described in this article were produced by the NOAA's Ocean Service through its National Status and Trends Program (NSandT)"

MEASUREMENT QUALITY OBJECTIVESSite location - Sampling sites were located by GPS with a manufacturer reported position accuracy of better than 3 meters in DGPS mode. Coordinates are expressed in units to the nearest 0.0001 decimal degrees. An acceptable tolerance goal for siting was that the sampling location be established within 0.2nm (+/- 120ft) of the given coordinates. In the event the vessel could not navigate to the site (i.e., too shallow) or the bottom type was not appropriate (i.e., rock or shellfish bed) then the first alternate site was substituted. In the event the first alternate could not be sampled then the second alternate site was sampled. Organic and Inorganic Contaminants - The measurement quality objectives of the Kachemak Bay Project specify accuracy and precision requirements of 30% for organic analytes and 15% for inorganic analytes in sediment samples. Water column measurements - Water column monitoring instrumentation was calibrated based on manufacturer's recommendations (YSI Corporation). Depth was recorded from the vessel fathometer.Benthic taxonomy-The minimum acceptable sorting efficiency was 95%. The minimum acceptable taxonomic efficiency was 95%. ACTUAL MEASUREMENT QUALITY - Water column measurements: Fields are arranged as follows: Measurement; Units; Expressed to Nearest.DO; mg/L; 0.1. Salinity; ppt; 0.01. Specific Conductance; mS/cm; 1. Depth; Meters; 0.5. Temperature, C, 0.1.Secchi depth; feet; 1.0.

Data are believed to be complete

All chemical contaminant values have been rounded to three significant digits. To accommodate the wide range of values, all concentration values have been formatted to the thousandth unit (0.001). The actual precision is as listed below. Metals, variable ug/g; Butlytins 0.01 ng Sn/g; PAHs 0.1 ng/g; PCBs 0.01 ng/g; Pesticides 0.01 ng/g. DATA QUALITY ASSURANCE PROCEDURES Site location - Handheld GPS units were compared daily with vessel GPS units. Organic and Inorganic Contaminants - QA procedures include blanks, spiked samples, and standard reference materials with each batch of samples. Any batch failing to meet the specifications presented in the "Measurement Quality Objectives" section would be reanalyzed or rejected. Contact NSandT staff for additional information on the Quality Assurance Project Plan Water column measurements - fields are arranged as follows: Indicator; QA sample type or measurement; Data generated for measurement quality. DO; Water-saturated air calibration; Difference between probe value and saturation level. Salinity; Seawater standard; Difference between probe measurement and standard value. Specific Conductance; Seawater standard; Difference between probe measurement and standard value. Temperature; Thermometer; +/- 1C. Benthic taxonomy-At a minimum, 10 percent of all samples were resorted and recounted on a regular basis. Ten percent of samples were randomly selected and re-identified. A voucher collection composed of representative individuals of each species encountered in the project was accumulated and retained.