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This Strategy Research Project addresses the relevance and challenges of executing engineer activities in support of U.S. Armed Forces participating in complex contingency operations. The complex, uncertain environment, in which U.S. Forces operate, requires extensive engineer effort to enhance national interests and to fulfill all mission objectives. By focusing on engineer activities conducted during the Stabilization Force (SFOR) 6, Bosnia-Herzegovina, numerous lessons learned can highlight the challenges of executing successful engineer operations in a joint, multinational, coalition in the context of contemporary military operations. Relevant doctrine, addressing the common and unique aspects of complex contingency operations is still in need of refinement These lessons requiring doctrinal refinement are evident in mine and unexploded ordnance removal, force mobility support, facility construction, force protection, and combined engineer projects. Moreover, combined engineer projects help to further engagement strategies with Multi-National Forces and former warring factions while expanding overall engineer capability. Engineer commanders must also deal with the full spectrum of military and civilian leadership challenges within a contingency area. To be effective, there must be an engineer command structure operating with proper doctrine and sufficient resources, to plan and execute the engineer operations so essential to the support of contemporary complex contingency operations.

As part of the San Juan River Basin Recovery Implementation Program (SJRIP), investigations of non-native fishes were conducted during 1991-1997 to characterize interactions with native fishes. The impacts of non-native fish species on natives has often been identified as a key impact, along with habitat alteration, that facilitates loss of native biological diversity. In the San Juan River, the endangered Colorado pikeminnow Ptychocheilus lucius and razorback sucker Xyrauchen texanus, as well as the other members of the native fish community, are the focus of the SJRIP. A major component of native fish recovery efforts in the San Juan River is the mimicry of the natural hydrograph, and SJRIP studies were designed to assess the response of the resident fish community to variable flow conditions affected the releases from upstream Navajo Dam. Section 5.4 of the SJRIP Long Range Plan identified several informational and action needs regarding non-native fish species: 1) characterize distribution and abundance patters of non-native fishes, 2) characterize habitats used by non-native fishes, 3) describe the food habits of non-native fishes, 4) characterize the response of non-native fishes to varying flow regimes, 5) develop a non-native fish stocking policy, 6) develop regulations to restrict bait-fish species harvest, 7) develop regulations to control importation of non-native fishes, and 8) monitor and evaluate non-native fishes control actions implemented as part of the SJRIP. This report presents results of non-native fishes investigations that address items 1-4 and 8 above. The distribution and abundance patterns of large-bodied non-native fishes were studied to determine responses to varying flow regimes. Sampling was primarily by raft-mounted electrofishing, but also included limited hoop and trammel netting. Main and secondary channel sampling collected 18 species of non-native fish. Channel catfish Ictalurus punctatus and common carp Cyprinus carpio were the m

Experimental and theoretical values are compared for the added masses of marine propellers and disks in axial translation. The experimental apparatus and procedure are described in detail, but the theoretical model is only outlined. Values predicted by the theoretical model were 15 to 30 percent smaller than the experimental results, except for the case of a circular disk in broadside motion where the results agreed within 2 percent. The generation of vorticity on the surfaces of the propellers and disks is proposed as a possible explanation for the discrepancies.