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.

A Bayesian mixture model for missing data in marine mammal growth analysis.

Abstract: Much of what is known about bottle nose dolphin (Tursiops truncatus) anatomy and physiology is based on necropsies from stranding events. Measurements of total body length, total body mass, and age are used to estimate growth. It is more feasible to retrieve and transport smaller animals for total body mass measurement than larger animals, introducing a systematic bias in sampling. Adverse weather events, volunteer availability, and other unforeseen circumstances also contribute to incomplete measurement. We have developed a Bayesian mixture model to describe growth in detected stranded animals using data from both those that are fully measured and those not fully measured. Our approach uses a shared random effect to link the missingness mechanism (i.e. full/partial measurement) to distinct growth curves in the fully and partially measured populations, thereby enabling drawing of strength for estimation. We use simulation to compare our model to complete case analysis and two common multiple imputation methods according to model mean square error. Results indicate that our mixture model provides better fit both when the two populations are present and when they are not. The feasibility and utility of our new method is demonstrated by application to South Carolina strandings data.

The Importance of Federal and Regional Partnerships in Coastal Observing

Abstract: Congress designed the U.S. Integrated Ocean Observing System (IOOS) as a partnership of 17 Federal agencies and 11 regional systems. Through collaborative projects and shared objectives, these partnerships improve the understanding of the coastal ocean environment by increasing the data available for modeling and analysis, improving forecasting capabilities, and through new decision support tool innovations. This chapter describes the benefits of IOOS partnerships and highlights five case studies. The case studies focus on enhancements to fisheries management, drinking water management, prediction of harmful algal blooms, and the benefits of a dedicated coastal ocean modeling testbed that intentionally brings together the research and operational communities.

Polyculture production of juvenile fishes for survival in nature

Abstract: Production of seed for stock enhancement projects requires consideration of the behavioural quality of the animals to be released in the wild. Our approach to improving behavioural quality of hatchery fish is to raise them in polyculture with the plants or animals that fish normally utilize as shelter in nature. Results suggest that such ‘naturalized’ systems provide a broad improvement in behaviour as both predator avoidance and feeding skills were improved relative to control hatchery fish. In addition fish in a naturalized system grew better and were more tolerant of stress than were fish reared by traditional hatchery methods. We hypothesize that the spatial heterogeneity of our ‘naturalized’ systems provided training in both hiding and seeking and that these activities improved feed conversion and stress tolerance.

Wireless Data Communication for Ocean Bottom Instrumentation

Abstract: The National Ocean Service (NOS) of NOAA maintains and operates a Physical Oceanography Real Time System (PORTS®) in the Nation’s major ports, harbors and bays. The traditional way to obtain real-time data from bottom mounted instruments is via underwater cable link. However, it is vulnerable to damages and costly to install and maintain. This paper describes a new approach utilizing wireless data telemetry. The system consists of an ocean bottom instrumentation platform and a data relay surface buoy. The bottom platform contains a RD Instruments (RDI) 1200 KHz acoustic Doppler current profiler (ADCP), a LinkQuest UWM1000 underwater acoustic transmitting modem, and acoustic recovery devices. The surface buoy supports a UWM1000 receiving modem and a Freewave 900MHz spread spectrum line-of-sight radio modem with antenna. The ADCP provides measurements of vertical current profiles at 6-minute interval and surface waves at hourly interval. The underwater acoustic modem transmits at 9.6 K baud rate the current data at the end of each 6-minute sampling, and wave data at the end of each 20-minute sampling. These data are relayed via radio at 48.5 K baud rate to a shore base station located at the University of Maryland’s Horn Point Laboratory about 16 miles away. There the data are then transferred in near-real-time via internet to NOS office in Silver Spring. Data are monitored and archived at both sites. The system was deployed off Taylors Island in the Chesapeake Bay in late July 2003 and was operated reliably through a 8-month period. It demonstrated successfully its measurement concept and capability for real-time monitoring of both currents and waves from a single ADCP instrument. This paper describes the overall system, component testings and field experiences, and presents some sample results.Copyright © 2004 by ASME

Physical and elemental analysis of Middle East sands from recent combat zones

Abstract: Objective: The lungs are uniquely exposed to the external environment. Sand and dust exposures in desert regions are common among deployed soldiers. A significant number of Veterans deployed to the Middle East report development of respiratory disorders and diseases.Materials and methods: Sand collected from Fallujah, Iraq and Kandahar, Afghanistan combat zones was analyzed and compared to a sand sample collected from an historic United States (U.S.) battle region (Fort Johnson, James Island, SC, Civil War battle site). Sand samples were analyzed to determine the physical and elemental characteristics that may have the potential to contribute to development of respiratory disease.Results: Using complementary scanning electron microscopy (SEM) imaging and analysis, and inductively coupled plasma mass spectrometry (ICP-MS), it was determined that Iraq sand contained elevated levels of calcium and first row transition metals versus Afghanistan and U.S. sand. Iraq sand particle texture was smooth and round, and particles were considerably smaller than Afghanistan sand. Afghanistan sand was elevated in rare earth metals versus Iraq or U.S. sands and had sharp edge features and larger particle size than Iraq sand.Conclusions: These data demonstrate significant differences in Iraq and Afghanistan sand particle size and characteristics. Middle East sands contained elevated levels of elements that have been associated with respiratory disease versus control site sand, suggesting the potential of sand/dust storm exposure to promote adverse respiratory symptoms. Data also demonstrate the potential for variation based on geographical region or site of exposure. The data generated provide baseline information that will be valuable in designing future exposure studies.