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Wier T.P.,EXCET INC. | Moser C.S.,EXCET INC. | Grant J.F.,Battenkill Technologies Inc. | First M.R.,EXCET INC. | And 3 more authors.
Marine Pollution Bulletin | Year: 2015

By using an appropriate in-line sampling system, it is possible to obtain representative samples of ballast water from the main ballast line. An important parameter of the sampling port is its "isokinetic diameter" (DISO), which is the diameter calculated to determine the velocity of water in the sample port relative to the velocity of the water in the main ballast line. The guidance in the U.S. Environmental Technology Verification (ETV) program protocol suggests increasing the diameter from 1.0× DISO (in which velocity in the sample port is equivalent to velocity in the main line) to 1.5-2.0× DISO. In this manner, flow velocity is slowed-and mortality of organisms is theoretically minimized-as water enters the sample port. This report describes field and laboratory trials, as well as computational fluid dynamics modeling, to refine this guidance. From this work, a DISO of 1.0-2.0× (smaller diameter sample ports) is recommended. © 2015 Elsevier Ltd. Source


Moser C.S.,EXCET INC. | Wier T.P.,EXCET INC. | Grant J.F.,Battenkill Technologies Inc. | First M.R.,U.S. Navy | And 4 more authors.
Biological Invasions | Year: 2016

Ships’ hulls can transport aquatic nuisance species, but there is little quantitative information about the magnitude of vessel biofouling on a global or regional scale. There does not exist a robust method to estimate the wetted surface area (WSA) of a particular fleet of ships, especially across the diversity of possible vessel types. An estimate of the total WSA of ship arrivals into a port or region is essential to determine the potential scope of biofouling and to inform management strategies to reduce the future invasions. Multiple statistical models were developed so commonly available ships’ parameters could be used to estimate the WSA for a given set of fleet data. Using individual ship characteristics and publicly available data from  ~120,000 active commercial ships in the world fleet, the method results in a total global minimum WSA estimate of approximately 325 × 106 m2. The size of the global fleet employed here is greater than the commonly cited vessel number of approximately 80,000–90,000, as we include ships <100 gross tons. Over 190,000 vessels were initially identified, representing a WSA of 571 × 106 m2, but active status of only 120,000 vessels could be confirmed. Reliable data were unavailable on the operating status of many additional and especially smaller vessels. This approach, along with a contemporary and comprehensive estimate of global WSA, when combined with knowledge of the different operational profiles of ships that may reduce biofouling (port residence times, steaming speeds, extent of antifouling coatings, cleaning frequency, etc.), can inform current numerical models and risk assessments of bioinvasions. © 2015, Springer International Publishing Switzerland (outside the USA). Source


Drake L.A.,U.S. Navy | Moser C.S.,EXCET INC. | Robbins-Wamsley S.H.,EXCET INC. | Riley S.C.,EXCET INC. | And 4 more authors.
Marine Pollution Bulletin | Year: 2014

Relatively large volumes of water-on the order of cubic meters-must be sampled and analyzed to generate statistically valid estimates of sparsely concentrated organisms, such as in treated ballast water. To this end, a third prototype of a shipboard filter skid (p3SFS) was designed and constructed. It consisted of two housings (each containing a 35. μm mesh filter bag) and its own pump and computer controller. Additionally, the skid had a drip sampler, which collected a small volume (~10. L) of whole (unfiltered) water immediately upstream of the housings. Validation of the p3SFS occurred in two segments: (1) land-based trials, in which the collection of organisms ≥50. μm (nominally zooplankton) by the p3SFS was compared to a plankton net, and (2) shipboard trials, in which ballast water was sampled aboard a ship. In both types of trials, the data collected showed the filter skid to be an appropriate flow-through sampling device. © 2014. Source

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