National Ocean Service

About: National Ocean Service is a government organization based out in Silver Spring, Maryland, United States. It is known for research contribution in the topics: Algal bloom & Population. The organization has 500 authors who have published 643 publications receiving 46096 citations.

Distribution and sources of PCBs (Aroclor 1268) in the Sapelo Island National Estuarine Research Reserve

Abstract: Aroclor 1268 is a highly chlorinated PCB mixture that was released into the aquatic environment near Brunswick, GA (BR), as a result of decades of local industrial activity. This extensive contamination has led to US EPA Superfund designation in estuarine areas in and around Purvis Creek, GA. Roughly 50 km to the northeast is the Sapelo Island National Estuarine Research Reserve (SI) where previous studies have documented unexpectedly high Aroclor 1268-like PCB levels in blubber and plasma samples of resident bottlenose dolphins. This result led to a collaborative effort to assess the PCB patterns and concentrations in SI sediment and fish (as potential vectors for PCB transfer to SI resident dolphins). Thirty SI randomly assigned stations were sampled for sediment PCB levels. Additionally, fish were collected and analyzed from SI (n = 31) and BR (n = 33). Results were pooled with regional assessments of PCB concentrations from South Carolina and North Carolina in an effort to determine the association of Aroclor 1268 levels in SI samples. Results indicated that PCB levels in sediment and fish are much lower in the SI estuary compared to BR sediment and fish concentrations. However, PCB congener profiles for both sediments and fish were similar between the two locations and consistent with the Aroclor 1268 signature, indicating possible transport from the Brunswick area. A likely source of Aroclor 1268 in dolphins from SI is contaminated fish prey.

Detection and Surveillance of Harmful Algal Bloom Species and Toxins

Abstract: The ability to mitigate the adverse impacts of harmful algal blooms (HAB) on humans, wildlife, fisheries, and ecosystems, as well as to identify the environmental factors driving HAB population growth and toxicity, is based largely on early detection of causative organisms and their toxins. This chapter explores a wide range of organism and toxin detection methods and technologies. It describes the fundamental principles of operation/conduct. It outlines the prospects for future advances in bloom and toxin detection/surveillance capabilities. Molecular methods used to detect organisms are potentially faster and more accurate than light microscopy (LM) methods. Monoclonal antibodies (MAbs) and polyclonal antibodies have been used to detect cultured and field‐collected cells of a wide variety of harmful algae. Immunoassays are based on antibodies recognizing and binding to one or more epitopes or antigenic determinants on a toxin molecule. The Enzyme‐Linked Immunosorbent Assay, ELISA has been the format of choice for most commercial algal toxin detection kits.

Integrated Environmental Modeling and Assessment of Coastal Ecosystems: Application for Aquaculture Management

Abstract: This article presents an approach that couples coastal ecosystem modeling with integrated environmental assessment methodologies to support coastal management. The focus is to support the development of an ecosystem approach to aquaculture management including interactions with watershed substance loading. A Chinese bay, with intense aquaculture and multiple catchment uses, and where significant modeling efforts were undertaken is used as a case study. The ecosystem model developed for this bay is used to run scenarios that test the local management strategy for nutrient reduction. The corresponding ecological and economic impacts of the managers’ scenarios are analyzed by means of the Differential Drivers-Pressure-State-Impact-Response (ΔDPSIR) analysis. Emphasis is given to the analysis of the eutrophication process in the bay including present eutrophic condition and the expected changes due to the simulated scenarios. For this purpose, the Assessment of Estuarine Trophic Status (ASSETS) screening mode...

Using Procedural Blanks to Generate Analyte-Specific Limits of Detection for Persistent Organic Pollutants Based on GC-MS Analysis

Abstract: Several methods are used to generate a limit of detection for organic pollutants measured by gas chromatography–mass spectroscopy (GC-MS); all have theoretical and practical drawbacks. The current project investigated two common existing methods (statistical and empirical) for applicability to chromatographic properties from real samples, comparing these with a new proposed method using procedural blanks to estimate a minimum detectable peak area. Weaknesses of all three methods are discussed. The proposed method was superior to other examined methods in that it provided analyte-specific limits of detection linked to the recovery of mass-labeled internal standards for every analyte within every sample. Other identified quality assurance benefits included the following: enhanced protection against false positives; providing a sensitivity performance metric across batch, analyst, and instrument; enabling chemists with discretionary decisions specific to every analyte regarding detectability and interference...