PDF/Textbook Anadromous Fish Habitat In Californias Mediterranean Climate Watersheds Full Download

Anadromous Fish Habitat in California's Mediterranean-climate Watersheds

Author: Jeff John Opperman
Publisher:
ISBN:
Category :
Languages : en
Pages : 544

Book Description

The Influence of Land Use and Mediterranean Seasonality on California Stream Fishes

Author: Kristina Yoshida
Publisher:
ISBN:
Category :
Languages : en
Pages : 108

Book Description
Freshwaters ecosystems support extraordinary biodiversity relative to their extent and provide important societal benefits. As such, freshwater environments and biota are often heavily impacted by anthropogenic activities. Freshwater fishes in Mediterranean-climate regions are especially impacted because of large human populations in these regions and extensive agricultural production, extensive river modification for flood control and to meet societal demands, and because these systems are heavily invaded by non-native organisms. The distribution and ecology of freshwater fishes in Mediterranean-climate regions are also influenced by the distinct wet and dry periods and the high inter-annual variability in precipitation. Thus, efforts to manage and conserve native fishes in Mediterranean-climate regions require understanding both the effects of human disturbance and the strong seasonality that characterizes these regions. In this dissertation, I examine the relationship between land use and Mediterranean seasonality on freshwater fishes in streams within the greater San Francisco Bay region in California, USA. In my second chapter, I use a multivariate approach to explore variability among fish communities in 25 Bay Area watersheds. I found that a combination of local (water conductivity) and watershed-scale factors (percent forested watershed, watershed area, elevation) were important predictors of fish communities across sites. Furthermore, watershed-scale factors had indirect effects on fish communities through their influence on a local-scale factor, water conductivity. The results of this chapter highlight the importance of considering both the direct and indirect effects of watershed-scale factors on freshwater fish communities. In my third chapter, I continued my analysis of land use and fish communities with a focus on contemporary land change. For this chapter, I performed a resurvey study, surveying the habitat and fish communities in 32 sites in the Alameda Creek Watershed that had been surveyed by Dr. Robert Leidy in the mid-1990s, including sites in the rapidly urbanizing Livermore Valley region. Again using a multivariate approach, I found that the increase in urbanization across an approximately 16-year period was related to change in fish community composition, a decline in native species richness, and a decline in a common native cyprinid - changes that were not observed in another part of the watershed that has experienced little land use change in the last 16 years. The relationship between land use change and fish community change was strongest when considering land use change at a local scale. These results suggest that ongoing land change alters fish communities and that contemporary resurveys are an important tool for examining how freshwater taxa respond to recent and ongoing environmental change. In my final chapter, I assessed how seasonal drought, a characteristic feature of Mediterranean-climate systems, influenced food webs in a small intermittent stream in Marin County, CA that provides rearing habitat for threatened steelhead trout (Oncorhynchus mykiss). I used stable isotopes of carbon and nitrogen to characterize food web structure and the trophic position of a suite of predators in this system, including O. mykiss and several macroinvertebrate predators. I compared food web snapshots across time, as well as between permanent and temporary pools. I found that the intermittent stream food web remained relatively stable across time and did not differ between pool types. However, I also found significant changes in the trophic position, niche width, and mean [delta]13C values for aquatic predators. This study provides an important first look at the trophic ecology of an imperiled fish species in intermittent streams during the summer drought season, and emphasizes that food chain length increases across the drought season, possibly because invertebrate prey are concentrated with declining water levels. In conclusion, my research shows that anthropogenic factors at the watershed scale influence instream conditions and freshwater fish communities, and emphasizes that contemporary changes in land use can have subtle changes on fish community structure, which may be indicative of future declines of extirpations of native fishes. Finally, my research shows that changing conditions across the summer drought season lead to shifts in the trophic ecology of some, but not all, aquatic predators, including threatened steelhead trout. Overall my research contributes to a growing body of research that demonstrates how multi-scale natural and anthropogenic factors influence freshwater fishes in Mediterranean-climate region.

Anadromous Fish Habitat Management on Public Lands

Author: BLM Anadromous Fish Habitat Team
Publisher:
ISBN:
Category : Anadromous fishes
Languages : en
Pages : 40

Book Description
"Describes anadromous fish resources on public lands, summarizes current management, and outlines a twelve year program (FYs 1989-2000) to maintain, protect, and enhance anadromous habitats through specific management actions and habitat improvement projects"--Page 3.

Working Paper on Restoration Needs

Author: U.S. Fish and Wildlife Service
Publisher:
ISBN:
Category : Fish habitat improvement
Languages : en
Pages : 426

Book Description

Restoring Ecological Function by Mimicking Natural Processes

Author: Jacob Van Epen Katz
Publisher:
ISBN: 9781321806519
Category :
Languages : en
Pages :

Book Description
Chapter 1: Impending extinction of salmon, steelhead, and trout (Salmonidae) in California. California contains the southernmost native populations of most Pacific Coast salmon and trout, many of which appear to be rapidly headed toward extinction. A quantitative protocol was developed to determine conservation status of all salmonids native to the state. Results indicate that if present trends continue, 25 (78%) of the 32 taxa native to California will likely be extinct or extirpated within the next century, following the bull trout (Salvelinus confluentus), which was extirpated in the 1970s. California's salmonids are adapted to living in a topographically diverse region with a Mediterranean climate, characterized by extreme seasonal and inter-annual variability in streamflow. Consequently, California salmonids have evolved extraordinary life history diversity to persist in the face of stressful conditions that often approach physiological limits. The spatial distributions of California salmonids vary from wide-ranging anadromous forms to endemic inland forms persisting in only a few kilometers of stream. Eighty-one percent of anadromous taxa are threatened with extinction and 73% inland taxa are either threatened or already extinct. Although specific drivers of decline differ across species, major causes of decline are related to increasing competition with humans for water, human degradation of watersheds, and adverse effects of hatchery propagation. Climate change, interacting with the other causes of decline, is increasing the trajectory towards extinction for most populations. Bringing all of California's salmonid fishes back from the brink of extinction may not be possible. If there are bold changes to management policy, however, self-sustaining populations of many species may be possible due to their inherent ability to adapt to changing conditions. Chapter 2: Floodplain Farm Fields Provide Novel Rearing Habitat for Chinook Salmon. When inundated by floodwaters, river floodplains provide rich food resources and high quality habitat for many species of wildlife. Globally, many rivers have been leveed and floodplain wetlands drained, primarily for flood control and conversion to agriculture. In the Central Valley of California, USA, where less than 5% of floodplain wetland habitats remain, a critical conservation question is how farmlands located on floodplains can be managed to provide increased habitat benefit to fish and wildlife. In this study agricultural fields located on the Sacramento River floodplain were intentionally inundated after the autumn rice harvest to mimic natural floodplain inundation patterns and determine if they could provide shallow-water rearing habitat for imperiled Sacramento River fall-run Chinook salmon (Oncorhynchus tshawytscha). Approximately 10,000 juvenile fish were reared on two hectares for six weeks when fields were idle between fall harvest and spring planting. Growth rates of juvenile salmon (average 0.76 mm/day) reared in this surrogate floodplain habitat were among the most rapid ever documented in fresh water in California and survival was high (minimum estimated survival 57%). The apparent compatibility of crop production and fish and wildlife habitat on the same ground demonstrates the ecological and economic benefits of reconciling management of agricultural working landscapes with recovery of native species. Chapter 3: Managed Inundation of Agricultural Floodplains Produces Record Growth in Juvenile Chinook Salmon. Floodplains are important engines of seasonal productivity in river ecosystems. However, in North America and Europe over 90% of floodplains habitats are no longer hydrologically connected to rivers, representing a significant loss of riverine ecosystem food web productivity. Expanding inundated floodplain area increases the volume of the photic zone, the uppermost portion of the water column, where sunlight is converted to carbohydrates by phytoplankton. Greater extent of shallow floodplain augments overall food availability and provides important aquatic habitats for many species. For example, invertebrates are in greater abundance on floodplains than in adjacent river channels, enhancing foraging success of fish that gain access to these seasonally inundated aquatic habitats. Like many large river valleys globally, the Central Valley of California, USA, (encompassing the Sacramento and San Joaquin River watersheds) has lost the majority of its floodplain habitat, primarily to conversion to agriculture. However, remnant floodplains still exist and are managed as flood bypasses which function in the winter wet season as "pressure relief valves," allowing floodwaters to pass safely around vital infrastructure and urban areas. In the summer dry season, bypasses are actively farmed. Managed inundation of agricultural floodplains may offer a means of regaining some of the ecological benefits of floodplains for native fish and wildlife while continuing to support flood protection and production agriculture, thereby creating a landscape where native species and human uses can coexist. An example of such reconciliation is Yolo Bypass, a farmed floodway where two decades of managed winter inundation of post-harvest rice fields--in the agricultural off-season when farm fields are idle--creates wetland habitat for millions of waterfowl using the critically important Pacific Flyway. Recent studies have shown that managed inundation can also provide suitable floodplain foraging habitat for native fish species such as juvenile Chinook Salmon. In order to better understand how rice farming practices affect the quality of reconciled winter rearing habitat for juvenile fall run Chinook Salmon (Oncorhynchus tshawytscha), we built and experimentally manipulated nine replicated two-acre rice fields. Fields shared a common layout and water source. Each was randomly assigned to one of three post-harvest farming options generally used in the Yolo Bypass; fallow, leaving standing rice stubble, or tilling to incorporate the stubble into the soil. Each field was stocked with approximately 4,500 juvenile salmon. Weekly sampling for water quality, invertebrate abundance and diversity, and fish growth and survival was conducted for 6 weeks, after which fields were drained and fish counted, measured

Anadromous Fish Habitat in California's Mediterranean-climate Watersheds

The Influence of Land Use and Mediterranean Seasonality on California Stream Fishes

Anadromous Fish Habitat Management on Public Lands

Working Paper on Restoration Needs

Restoring Ecological Function by Mimicking Natural Processes

California Water Resources Center

Water Resources Center Report

Living Among the Fish

Annual Report

The Politics and Practice of Watershed Restoration