The First Record of Bigscale Logperch and Range Expansions of Smallmouth Buffalo, White Crappie, and Gizzard Shad in Arizona

Bigscale Logperch Percina macrolepida is reported and substantiated for the first time in Arizona. A single specimen was collected during a routine survey of Cow Springs Lake on September 26, 2017, preliminarily identified as Percina sp . , preserved, and retained for species identification. We verified the specimen was a Bigscale Logperch through genetic analysis. Review of published literature and the U.S. Geological Survey Nonindigenous Aquatic Species Database suggests that this is the first known occurrence of Bigscale Logperch in Arizona. Further, three additional non-native species were detected during our sampling events on June 21 and September 26, 2017—Smallmouth Buffalo Ictiobus bubalus , White Crappie Pomoxis annularis , and Gizzard Shad Dorosoma cepedianum —representing the first collection of these species in the Little Colorado River basin that we are aware of. We recommend further evaluation of the ecology, distribution, and abundance of these four non-native species to better understand their effect on the native fishes of the watershed and the likelihood of establishment in the watershed and elsewhere in Arizona.

Trim and Draft Control Capability of the Variable Buoyancy Ship

The Variable Buoyancy Ship concept has been developed to address the problem of the introduction of nonindigenous aquatic species (NIS) into coastal waters. While this ship design concept essentially eliminates the transport of NIS across the globe, it presents special problems for operators with respect to their control of trim and draft. An investigation was, therefore, undertaken to assess this capability and ensure that adequate capability would be provided. To better visualize this issue, the equilibrium polygon used in early submarine design has been adapted to provide an effective way to characterize the trim and draft control capability of surface vessels. The results of this investigation and resulting design concept modifications are presented.

Are ecological goals suitable references to assess river restoration results? The downstream parts of the rivers Rhine and Meuse as an example

The paper presents the historical analysis of the human development of the Meuse and the Rhine rivers in the Netherlands. Causes and consequences of the geomorphological alterations of the rivers’ natural beds have been discussed. The paper provides facts and up-to-date hypothesis aimed to explain the process of new (nonindigenous) aquatic species emergence process caused by river water quality and biotopes restoration in the Netherlands.