Better understanding of fish behavior is vital for recovery of many endangered species including salmon. The Juvenile Salmon Acoustic Telemetry System (JSATS) was developed to observe the out-migratory behavior of juvenile salmonids tagged by surgical implantation of acoustic micro-transmitters and to estimate the survival when passing through dams on the Snake and Columbia Rivers. A robust thr...

Nonindigenous species (NIS) pose one of the dominant environmental threats to biological diversity (Vitousek et al. 1996, Simberloff et al. 2005) and are cited as a cause of endangerment for 48% of the species listed under the US Endangered Species Act (ESA) (Czech and Krausman 1997, Wilcove et al. 1998). In 2005, NIS cost the US economy in excess of $120 billion (Pimentel et al. 2005), and the...

Serum biochemical parameters are important aspects in the management of endangered species. The values of these parameters can be used for confirming the maturity and for monitoring any changes in the quality of waters and related soils. The aim of this research was to determine the reference values of biochemical factors in Acantopagrus latus and Epinephelus coioides. Blood samples were collec...

Diversion of river water has diminished freshwater flow into many estuaries worldwide, yet the effects of these diversions on marine fisheries, many of which depend on estuaries, are largely unexplored. We document the impact of diverting Colorado River flow from the Gulf of California on the life history of a now-endangered marine fish (Totoaba macdonaldi, Sciaenidae). Growth increments in pre...

On May 15, 2009, I sent a letter with documents on an accompanying compact disk to the California Fish and Game Commission on behalf of the Center for Biological Diversity to apprise the Commission of scientific studies pertinent to the Commission's reconsideration of the Petition to List the American Pika under the California Endangered Species Act. That letter discussed the U.S. Fish and Wild...

Anthropogenic structures (e.g. weirs and dams) fragment river networks and restrict the movement of migratory fish. Poor understanding of behavioural response to hydrodynamic cues at structures currently limits the development of effective barrier mitigation measures. This study aimed to assess the effect of flow constriction and associated flow patterns on eel behaviour during downstream migra...

The American paddlefish, Polyodon spathula (Walbaum), is an endangered acipenserid fish. Its wild populations are supplemented with stocking material that is obtained by conducting artificial spawning in aquaculture conditions. When fish are bred in captivity, it is important to select breeding pairs that will produce the most genetically diverse progeny, since this permits maintaining the fitn...

A commonly overlooked aspect of conservation planning assessments is that wildlife managers are increasingly focused on habitats that contain non-native species. We examine this management challenge in the Gila River basin (150,730 km(2)), and present a new planning strategy for fish conservation. By applying a hierarchical prioritization algorithm to >850,000 fish records in 27,181 sub-watersh...

Mosquitofish (Gambusia affinis) is an example of a freshwater fish species whose remarkable diffusion outside its native range has led to it being placed on the list of the world's hundred worst invasive alien species (International Union for Conservation of Nature). Here, we investigate mosquitofish shoaling tendency using a dichotomous choice test in which computer-animated images of their co...

Since the mid-1990s, Bombus occidentalis (Green) has declined from being one of the most common to one of the rarest bumble bee species in the Pacific Northwest of the United States. Although its conservation status is unresolved, a petition to list this species as endangered or threatened was recently submitted to the U.S. Fish and Wildlife Service. To shed light on the conservation situation ...