Seminar on Discarded Munitions

Collecting a sea star near a sea-dumped munition. /Courtesy of Hawaiʻi Undersea Military Munitions Assessment

The Hatfield Marine Science Center’s research seminar continues with a talk on discarded munitions. It takes place on Thursday, Oct. 19, at 3:30 p.m., in the auditorium of the Gladys Valley Marine Studies Building at HMSC (2030 S.E. Marine Science Dr. in Newport).

This is a hybrid event; use this link to join via Zoom.

The speaker is Michael S. Tomlinson, a consulting Coastal Oceanographer.

About the talk:

"The US Department of Defense discarded excess, obsolete, or unserviceable munitions in nearshore marine waters of the US and its territories from the early 1900s through 1970. Chemical munitions and agents (e.g., mustard gas, Lewisite) typically were discarded in deeper water but some conventional munitions were discarded at water depths reachable by recreational divers. One such area, Ordnance Reef, is located off the leeward side of Oʻahu, Hawaiʻi. The Army’s National Defense Center for Energy and Environment (NDCEE) was tasked to assess the change in conditions (e.g., presence of munition constituents and concentrations) at Ordnance Reef following a technology demonstration whereby munitions at depths from ~9 to ~36 m were recovered with a Remotely Operated Underwater Munitions Recovery System (ROUMRS). Pre- and post-ROUMRS sampling of sediment and biota (traditional Hawaiian food) was conducted by the University of Hawaiʻi at Mānoa (UHM). The results contained multiple non-detects (NDs), i.e., left-censored data. Fortunately, there are methods for statistically analyzing left-censored data without compromising the results caused by ignoring NDs or substituting values for NDs. While other statistics will be briefly discussed, this seminar concentrates on the use of a nonparametric ordination technique called nonmetric multidimensional scaling (NMDS) to identify the possible sources of the various analytes, particularly arsenic, lead, and energetics (e.g., dinitrotoluene) that may be found in the sediments and biota."