Water availability is a controlling factor in stream ecosystems with direct influences on habitat and aquatic ecosystem process, but little work has been done evaluating how biota respond to natural variations in low flow conditions during summer, and which biotic or abiotic features in the system may link most closely...
In light of water scarcity and the impacts of climate change, there is an increased need to understand the interaction between land use characteristics and ecohydrologic processes in semiarid regions. Additionally, many semiarid and arid regions face various land management challenges, including woody plant encroachment, decreased snowpack, and increased stream...
Rivers support some of Earth’s richest biodiversity and provide essential ecosystem services to society, but they are often fragmented by barriers to free flow. In Europe, attempts to quantify river connectivity have been hampered by the absence of a harmonized barrier database. Here we show that there are at least...
Domesticated dogs can form attachment bonds with their owners and use them as a secure base to receive comfort during distress and confidence to explore novel environments. Owners often adopt multiple dog in hopes they will have ameliorative effects during periods of absence from their owner. The purpose of this...
An improved understanding of the ecohydrologic relationships in semiarid rangelands is imperative for the development of effective rehabilitation and land management practices. This thesis addresses the ecohydrologic relationships of two significant issues concerning semiarid rangeland ecosystems: western juniper encroachment and increasing stream temperatures.
This thesis is divided into two chapters;...
Secondary metabolites are synthesized by many microorganisms and provide a fitness benefit in the presence of competitors and predators. Secondary metabolism also can be costly, as it shunts energy and intermediates from primary metabolism. In Pseudomonas spp., secondary metabolism is controlled by the GacS-GacA global regulatory system. Intriguingly, spontaneous mutations...
Worldwide, in recent years capture fisheries targeting lower-trophic level forage fish and euphausiid crustaceans have been substantial (∼20 million metric tons [MT] annually). Landings of forage species are projected to increase in the future, and this harvest may affect marine ecosystems and predator-prey interactions by removal or redistribution of biomass...
In the face of dramatic declines in groundfish populations and a lack of sufficient stock assessment information, a need has arisen for new methods of assessing groundfish populations. We describe the integration of seafloor transect data gathered by a manned submersible with high-resolution sonar imagery to produce a habitat- based...
Dramatic declines in several groundfish populations have occurred along
the U.S. West Coast during the last decade (PFMC 1999, Sampson 1997,
Ralston 1998, Bloeser 1999). One problem exacerbating these declines is
insufficient stock assessments, especially for species of west coast rockfish
(Family Scorpaenidae, Genus Sebastes) which comprise the core of...
Full Text:
REPORT OF
NicoleM. Nasby for the degree of Master of Science in Marine Resource Management presented on
Dramatic declines in several groundfish populations have occurred along
the U.S. West Coast during the last decade (PFMC 1999, Sampson 1997,
Ralston 1998, Bloeser 1999). One problem exacerbating these declines is
insufficient stock assessments, especially for species of west coast rockfish
(Family Scorpaenidae, Genus Sebastes) which comprise the core of...