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.

Integrating multiple techniques to identify stock boundaries of common bottlenose dolphins (Tursiops truncatus)

Abstract: Under US policy, a stock is a group of animals shown to be demographically independent from other such groups. Evidence of demographic delineations for marine mammal stocks is gained primarily through genetic analysis. However, additional techniques play an important role in determining fine-scale ranging patterns that can be used to define a stock's geographic boundaries. In cases where genetic studies have not yet been performed, movement and ranging pattern data are essential in identifying a targeted geographic region for tissue sampling and genetic studies. Photo-identification surveys, vessel-based radio telemetry, automated radio telemetry systems (ARTS), and satellite-linked telemetry are sampling techniques that have been used to determine common bottlenose dolphin ranging patterns and provide detailed insight into stock boundaries. The results of near simultaneous use of these sampling techniques are compared using data from a case study of bottlenose dolphins within the estuaries of southern Georgia. Satellite-linked and radio telemetry were determined to be useful sampling techniques for identification of short-term ranging patterns. Satellite-linked telemetry had the second lowest cost per location ($122) and identified dolphin ranging patterns within and outside of the study area boundaries. Vessel-based radio telemetry was more costly ($195 per location) and had relatively limited tracking coverage. However, this sampling technique permitted visual observations of animal and tag condition. The combination of vessel-based radio telemetry and ARTS, which had the lowest cost per location ($34), was an effective method for determining ranging patterns of tagged individuals within and outside of the study area. Photo-identification surveys, relative to satellite-linked and radio telemetry, were not as efficient for determination of targeted individuals’ short-term ranging patterns and had the highest cost per location of the four sampling techniques ($292). However, photo-identification is more effective than any other technique for compiling data on large numbers of individuals within a designated study area. Photo-identification surveys are essential for long-term monitoring and provide additional insight into dolphin stock structure that cannot be determined through telemetry alone. Copyright © 2013 John Wiley & Sons, Ltd.

Sediment quality of the Neuse River estuary, North Carolina: an integrated assessment of sediment contamination, toxicity, and condition of benthic fauna

Abstract: A study of ecological conditions associatedwith bottom sediments in the Neuse Riverestuary, U.S.A. was undertaken during summer1998. Sampling of macroinfauna, sedimentsfor toxicity and chemical contaminant analyses,and physical properties of water was carriedout synoptically over a four-day period at 20stations from the mouth of the Neuse River atPamlico Sound to approximately 90 km upstream. The distribution and condition of benthicinfauna were found to vary in response tonatural and anthropogenic factors, and apparentassociations between degraded infaunalcondition and sediment contamination and/ortoxicity were observed over roughly half of thesampled area (7 stations, 47% area). With fewexceptions, degraded benthic conditions wereassociated with significant sedimentcontamination or toxicity. High sedimentcontaminant levels were found to occur almostexclusively in fine-grained, organic-rich muds. These results suggest that high organic loadingand chemical contaminant inputs to the NeuseRiver, coupled with low freshwater dischargerates and high residence times in the lowerestuary, have contributed to degraded benthicconditions at these sites.