This article examines the nature of agrarian change in the Kusasi area of north-east Ghana. In focusing upon the dynamic of population growth the study has relevance to the recently rejoined discussion concerning the relationship between population growth and agricultural change. The context in which population growth is proceeding in Kusasi is presented as significantly different from that of other parts of tropical Africa where population growth has been recognised as the dynamic bringing about more productive and sustainable systems. In Kusasi's peripheral and subsistence-oriented economy population growth has led to increased pressure on the biological resources of the region. The permanent compound farming system of the area is now increasingly unable to provide sufficient subsistence for household needs, and, although expansion of farmland into areas recently freed from onchocerciasis is taking place, this is interpreted as merely a temporary respite in the interrelated processes of continuing environmental degradation and declining productivity under the prevailing agricultural system. The article raises the question of how, in the absence of progressive change brought about by population growth, development for regions like Kusasi is to be envisaged. Current programmes of agricultural development are considered in the context of past initiatives.

The Green River system in the upper Colorado River basin supports populations of endangered Razorback Sucker Xyrauchen texanus and Colorado Pikeminnow Ptychocheilus lucius. Documented spawning areas for these species are few and occur mainly in the Green River main stem and the lower reach of the tributary Yampa River. Herein, we report spawning by both species in an additional Green River tributary, the White River. We documented Razorback Sucker and Colorado Pikeminnow larvae and early juveniles in a 20‐km reach of the lower White River, Utah, in 2011. Movement of hatchery‐produced Razorback Sucker adults into the White River and subsequent reproduction suggests that these fish use the system to complete important life history processes. Presence of spawning areas for two endangered fishes in the White River emphasizes the important role of tributaries for providing spawning and rearing habitat for native and endangered fishes. Received April 2, 2013; accepted July 18, 2013

No abstract

In order to increase detections of razorback suckers Xyrauchen texanus tagged with passive integrated transponders in the upper Colorado River basin, we deployed two passive instream flat-plate antennas (33 × 68 cm) at a razorback sucker spawning location in the Green River, Utah, during spring of 2012 and 2013. Over the course of 29 d in 2012 and 90 d in 2013, the antennas detected 569 razorback suckers, 19 Colorado pikeminnow Ptychocheilus lucius, 16 flannelmouth suckers Catostomus latipinnis, and 1 bluehead sucker Catostomus discobolus. Despite extensive sampling via boat electrofishing (rafts and hard-bottom boats) and netting (fyke, trammel, and gill) in wetlands that occurred from the 1990s to present in the upper Colorado River basin, a large number of tagged razorback suckers and Colorado pikeminnow, including a fish released in 1996, were detected for the first time by our antennas. Our data indicate that the detectability of razorback suckers, and precision and accuracy of survival and population estimates might be increased significantly with the addition of data gathered by passive instream flat-plate antennas in the Green River.

Native fishes continue to decline in abundance and distribution. One common practice to ensure native fish persistence has been to introduce fish into new habitats. Though these introductions reduce the risk of extinction, often the introduced populations are not considered in the Endangered Species Act (ESA) listing status in the same manner as extant populations. One instance where they were considered was when Least Chub Iotichthys phlegethontis were introduced into 23 locations within the Bonneville Basin between 2005 and 2013. In 2014, 10 of these populations were considered successful and were evaluated with the six remaining extant populations by the U.S. Fish and Wildlife Service. In this instance, Least Chub were removed from the candidate list in part due to these introduced populations, which increased the resiliency, redundancy, and representation for this species to persist now and into the foreseeable future. The creation of introduced fish populations is a conservation practice that needs to be considered as a potential tool for fisheries managers, not only to ensure persistence, but also to preclude the need for federal listing under ESA.