Using This Collection/Resources

Adversely affected [benthos] – Benthic communities characterized by Ecology’s binary Benthic Index as negatively impacted by natural or anthropogenic habitat changes or both

Anoxic - Deficient in oxygen

Anthropogenic – Human-caused

Azoic - No life present. For the purpose of our studies, azoic sediments means there are no benthic organisms present; however, there may be smaller organisms present like meiofauna and bacteria that we do not quantify.

AZTI Marine Biotic Index (AMBI) - index that classifies species into five ecological groups (EGs) based on their sensitivity to environmental stress (Borja et al., 2000; Borja et al., 2020; Sigovini et.al., 2013)

Benthic – Of, relating to, or occurring at the bottom of a body of water

Benthic carnivore – Feeding mode which consists of feeding on bottom-dwelling animals

Benthic Index – Since 1997, all Puget Sound sediment monitoring program benthic invertebrate samples have been assessed by best professional judgment of two or more benthic experts, using multiple lines of evidence, as either adversely affected or unaffected by natural or anthropogenic stressors. Details are described in our Quality Assurance Monitoring Plan.

Benthos – The flora and fauna found on the bottom, or in the bottom sediments, of a body of water

Biogeochemistry – For the purpose of our studies, biogeochemistry refers to the measurements of carbon and nitrogen in the surficial sediments.

Biomass – The mass of living biological organisms in a given area or ecosystem at a given time

Bioturbation – Disturbance of the sediment by the activities of living organisms

Bray-Curtis similarity – A measure of the similarity of two groups of organisms based on both species composition and abundance (or biomass). Bray-Curtis dissimilarity is the opposite, a measure of how dissimilar two groups of organisms are.

C:N – Ratio of total carbon to total nitrogen

Detritus – Dead particulate organic matter composed of leaves and other plant parts, animal remains, waste products, or other organic debris

Distance-based Redundancy Analysis (dbRDA): Another term for multivariate multiple regression is redundancy analysis (RDA), which is used to reveal linear combinations of predictor variables which explain the greatest variation in the multivariate response variable; dbRDA is RDA conducted with distance (dissimilarity) measures which may be other than Euclidean distance. A dbRDA plot is a method of visualizing the first two dimensions (those containing the most variation) of the multi-dimensional model fit. The closer the symbols are to each other, the more similar the samples are.

Dissimilarity metric – A measure of how dissimilar two samples are. Examples are Euclidean distance and Bray-Curtis dissimilarity.

ECY – Washington State Department of Ecology

EIM – Environmental Information Management – The Washington State Department of Ecology’s database which houses environmental data collected by the agency and its stakeholders

Euclidean distance – The smallest distance between two points. For two multi-dimensional samples, Euclidean distance is a function of the differences between corresponding variables in the samples.

EPA – United States Environmental Protection Agency

Facultative Carnivore – Feeding mode which consists of feeding on other animals, with the ability to switch feeding modes

Facultative Detritivore – Feeding mode which consists of ingesting detritus (broken-down plant and animal material), with the ability to switch feeding modes

Feeding Guild – A group of unrelated species that exploits the same class of trophic resources in a similar way

Filter-feeder – Feeding mode which consists of capturing and ingesting food particles suspended in water

Grab penetration depth – A measure of compactness of the sediments based on how deeply the grab bites into the sediments

Grain size – Size of individual sediment particles. For the purpose of our studies, grain size is expressed as percent by weight for each of four size classes: gravel, sand, silt, and clay. The sum of the silt and clay percentages is referred to as percent fines.

Herbivore – Feeding mode that consists of eating plants

HPAH – High-molecular-weight polycyclic aromatic hydrocarbon

km² – Square kilometers

LOTT – Lacey, Olympia, Tumwater, and Thurston County wastewater treatment plant

LPAH – Low-molecular-weight polycyclic aromatic hydrocarbon

Macrofauna – For the purpose of our studies, benthic invertebrates large enough to be collected on a 1-mm sieve (i.e., greater than 1 mm in size)

Major taxa abundance – Total abundance in each of five major groups

Marine Sediment Quality Vital Sign – The PSP’s Puget Sound Vital Signs are measures of the health of the Puget Sound ecosystem. Each Vital Sign is composed of one or more indicators, specific measures of condition that are compared to recovery targets (PSP, 2019). The SCI is one indicator in the current Marine Sediment Quality Vital Sign. With the revision of the Vital Signs, effective January 2022, the SCI will be an indicator in the Marine Water Quality Vital Sign (PSP, 2020), and the Marine Sediment Quality Vital Sign will be discontinued.

Mean SQS quotient (mSQSq) – The average ratio of contaminant concentrations to respective SQS. The mSQSq is a useful measure of the degree of chemical contamination. This index is a multi-chemical effects-based index that accounts for both the presence and relative concentrations of chemicals for which there are state standards (Long et al., 2006). A mean SQS quotient (mSQSq) is calculated by dividing chemical concentrations in the sediments at each station by their respective SQS values, then calculating the mean of those ratios. The higher the mSQSq, the greater the potential for toxicity to sediment-dwelling organisms (Long et. al., 2006).

Megafauna – Benthic invertebrate macrofauna weighing more than 2 g per organism

MSMT – Marine Sediment Monitoring Team

Multi-dimensional scaling (MDS) – A method for representing many-dimensional samples in a 2-dimensional plot such that the spacing of the points preserves as closely as possible the corresponding dissimilarities among the samples. Metric MDS (mMDS) uses the scale of the dissimilarity metric, whereas non-metric MDS (nMDS) uses only the ranks of the dissimilarities.

Multivariate AZTI Marine Biotic Index (M-AMBI) - a widely-used tool for assessing the ecological quality of marine and estuarine environments based on benthic (bottom-dwelling) macroinvertebrates. It integrates the AZTI Marine Biotic Index (AMBI) with metrics of species richness and diversity. These three metrics are combined using multivariate statistical techniques to produce the M-AMBI score

m² – Square meters

Omnivore – Feeding mode that consists of eating both plants and animals

Organic matter (OM) – Originates from the wastes and remains of carbon-based life forms like plants, animals, and humans. It consists of carbon and nutrients, including nitrogen. For the purpose of our studies, organic matter is represented by the measured values of organic carbon and nitrogen.

PAH – Polycyclic aromatic hydrocarbon

Partial Least Squares (PLS) regression – PLS regression is a way of reducing a large number of possibly correlated predictor variables before regression. Uncorrelated linear combinations of the predictor variables, called components, are generated to maximize the covariance between the predictor and response variables. The components are then used as the predictors in a regression of the response variables.

PBDE – Polybrominated diphenyl ether

PCB – Polychlorinated biphenyl

Pelagic – Inhabiting the water column

Pielou’s Evenness – Measure of equitability of distribution of individuals among species

Planktonic – Relating to small or microscopic organisms (plankton) that drift or swim weakly in a body of water

Priority Pollutants – A set of chemical pollutants regulated by the Environmental Protection Agency (EPA), and for which EPA has published analytical test methods

R² and Adjusted R² – R² (R-squared) is a measure of model fit. It indicates the proportion of variation in the dependent variable that is accounted for by the independent variables. However, R² increases with every independent variable added, even if the added variable doesn't have any influence on the dependent variable. The adjusted R² indicates the percentage of variation explained by only those independent variables that actually affect the dependent variable.

Sediment Chemistry Index (SCI) – The Sediment Chemistry Index is a measure of the degree of chemical contamination at each station. SCI values range from 0 (severely degraded) to 100 (highest quality) and categorize sediments as having minimum, low, moderate, or maximum levels of exposure to the chemicals for which the Washington State Sediment Quality Standards (SQS) have been defined. The target value for the SCI as an indicator within the PSP’s Marine Sediment Quality Vital Sign is 93.333..., corresponding to the bottom of the minimum exposure level. Details are described in our Quality Assurance Monitoring Plan.

Sediment Quality Standards (SQS) – The Sediment Quality Standards are sediment chemical concentrations below which adverse biological effects are not expected to occur or above which at least minor adverse impacts on benthic invertebrates are expected always to occur. The SQS are one of two sets of Washington State sediment criteria (Sediment Management Standards) that were derived with the apparent-effects threshold approach, a method of comparing sediment chemical concentrations with both sediment toxicity and adverse effects to the resident benthos. SQS are numerically equal to Sediment Cleanup Objectives, which are the regulatory criteria for cleanup of contaminated sediments, authorized under the Model Toxics Control Act RCW 70.105D (Ecology, 2013).

sp. – Indeterminate species

spp. – Multiple indeterminate species

Subsurface Deposit Feeder – Feeding mode which consists of ingesting sediment below the surface

Surface Deposit Feeder – Feeding mode which consists of ingesting sediment at the surface

Surface sediment - For the purpose of our studies, surface sediment refers to the top 3 cm layer of sediment collected for biogeochemical and chemical analyses.

Swartz Dominance – Minimum number of taxa accounting for 75% of the sample abundance

Taxa – Plural of taxon, which is species or higher-level taxonomic identification

Taxa group – For the purposes of our studies, taxa group refers to either a single phylum (e.g., Annelida, Arthropoda, Echinodermata, Mollusca) or a group of phyla (e.g., miscellaneous taxa, which includes multiple phyla like Nemertea, Cnidaria, and Bryozoa).

Taxa richness – Total number of taxa

TC – Total carbon

TIC – Total inorganic carbon

TN – Total nitrogen

TOC – Total organic carbon

Total abundance – Total number of organisms

Trophic – Of or relating to nutrition. The trophic level of an organism is the position it occupies in a food web.

TS - Total sulfides

Unaffected [benthos] – Benthic communities characterized by Ecology’s binary Benthic Index as not negatively impacted by natural or anthropogenic habitat changes

WAC – Washington Administrative Code

Zooplankton-eater – Feeding mode that consists of eating tiny planktonic animals (zooplankton)

δ¹³C – Isotopic signature of carbon, based on relative abundances of two stable isotopes, ¹³C and ¹²C, in a sample compared to a standard: 

δ¹⁵N – Isotopic signature of nitrogen, based on relative abundances of two stable isotopes, ¹⁵N and ¹⁴N, in a sample compared to air:

Data summaries for all reports are available upon request. For more information, contact our team.