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The effects of a prolonged drought on southern Steelhead Trout (Oncorhynchus mykiss) in a coastal creek, Los Angeles County, California
Full text linkLong-term lifecycle monitoring of federally endangered southern steelhead trout (Oncorhynchus mykiss) in Topanga Creek provides a unique opportunity to examine the health and abundance of a steelhead population before (2008-2011) and during (2012-2016) a prolonged drought. We found that the five-year drought resulted in a substantial and significant decline in available wetted habitat suitable for rearing and upstream migratory access for anadromous adults. The response of the steelhead population has been a significant reduction in anadromous spawning, distribution of rearing, and abundance of all life stages of anadromous and resident steelhead. After five years of drought a population that exceeded 325 individuals in 2008, now numbers fewer than 50 fish, and appears to be at extremely high risk of extirpation. Acknowledging the possibility of increased drought regionally and globally, the need to bolster southern steelhead resiliency to additional disturbance is paramount
Metrics for Equity in Transit-Oriented Development: A Case for Sustainable Investment in Los Angeles
No full textPublic transportation investments have the power to bring economic growth, mobility and environmental sustainability at the same time that they can reinforce segregation and income inequality. It is at this juncture that Los Angeles County faces a grand opportunity to develop equitably and sustainably. By doing so, low-income residents can be connected to a sophisticated transit network, and through it, jobs, amenities, and a low-carbon lifestyle– leading to sustainable growth for the region. For this reason, it becomes increasingly important to develop tools with which to measure equity outcomes around transit development. This study will use existing literature and interviews from representatives of the transit-oriented development (TOD) field to develop an equity screening metric that will ensure that development is both cognizant and applied, such that future development around transit is equitable, and benefits those who rely most on transit
Designing Equity: A case study of Pershing Square in Downtown Los Angeles
No full textThis paper evaluates the past and present revitalization of Pershing Square through equitable urban design strategies and community outreach tactics. Through comprehensive interviews and contextualization of census data to further support findings, this paper makes concise policy recommendations to further the process of curating equitable public spaces in cities
Range Expansion of the Eastern Fox Squirrel Within the Greater Los Angeles Metropolitan Area (2005-2014) and Projections for Continued Range Expansion
Full text linkMonitoring the spread and distribution of introduced species in an area can be challenging due to a variety of issues. Range expansion may exceed expected rates if the area of introduction is more suitable than expected, and may be slowed by an area in which it is difficult to establish a population. The species of interest in this study is the Eastern Fox Squirrel (Sciurus niger rufiventer) and the focus of the study is the spread of the species in Southern California. Previous studies have shown a steady and continuous spread from main points of introduction in Southern California and the species is now considered well established in the Los Angeles area. In this study, we collect, display, and discuss the spread of the Eastern Fox Squirrel in this area from 2005 through 2014 and include habitat suitability models to predict the future distribution of the species over time. Results show that the Eastern Fox Squirrel has spread east into Rancho Cucamonga, into southern portions of Irvine, and has maintained isolated populations in places such as San Diego and Riverside. Our models suggest future paths of movement for contiguous range expansion. Suggestions for species mitigation include controlling initial introductions of the species into new areas, and informing the public about continued spread of the species
The Organisms Living Around Energized Submarine Power Cables, Pipe, and Natural Sea Floor in the Inshore waters of Southern California
Full text linkBetween 1 February 2012 and 26 February 2014 using scuba, we surveyed the fishes, invertebrates, and macrophytes living on two energized submarine power cables, an adjacent pipe, and nearby natural habitat in southern California at bottom depths of 10–11 m and 13–14 m. Over the course of the study, average electromagnetic field (EMF) levels at the two cables (A and B) were statistically similar (Cable A = 73.0µT, Cable B = 91.4µT) and were much higher at these two cables than at either the pipe (average = 0.5µT) or sand (0µT). Overall, our study demonstrated that 1) the fish and invertebrate communities on cables, pipe, and natural habitat strongly overlapped and 2) there were differences between the shallower and deeper fish and invertebrate communities. We saw no evidence that fishes or invertebrates are either preferentially attracted to, or repelled by, the EMF emitted by the cables. Any differences in the fish or invertebrate densities between cables, pipe, and natural habitat taxa were most likely due to the differences in the physical characteristics of these habitats. As with the fishes and invertebrates, macrophytes did not appear to be responding to the EMF emitted by the cables. Rather, it is likely that differences in the plant communities were driven by site depth and habitat type
Does Estuary Restoration Design Alter the Fine Scale Movements of Grey Smoothhounds (Mustelus californicus) in Southern California?
Full text linkRestored estuaries in southern California are limited in size and shape by fragmentation from human development, which can in turn restrict habitat use. Thus, it is important to assess how habitat design affects how fish use restored estuaries. Acoustic telemetry tracking from prior studies revealed that Grey Smoothhounds (Mustelus californicus) used primarily the eelgrass ecotone and warm interior waters in Bolsa Chica Full Tidal Basin (BCFTB), a 1.48 km2 open-format marine dominated estuary. In this study, M. californicus utilized the Channel in Huntington Beach Wetlands Complex (HBWC), a smaller creek estuary. The Channel had more eelgrass than other available habitats but was also the coolest microhabitat, with temperatures below what M. californicus was found to select in BCFTB. Individuals may behaviorally thermoregulate by moving upstream, away from the HBWC Channel, during periods of incoming, cooler ocean water. Mustelus californicus translocated to different microhabitats within the HBWC selected the Channel habitat after the translocation regardless of where animals were released. Despite the large difference in available subtidal habitat between HBWC and BCFTB, no differences in patch size utilization distributions of M. californicus were observed. While individuals seem to shift between microhabitats based on temperature and eelgrass availability, the area size used by M. californicus appears to be the same within both sites despite the differences in overall size between sites. These results suggest that differences in microhabitat use may influence distribution patterns of M. californicus within each site, and therefore, shark abundance may vary with the restoration design (e.g. basin versus channel) and the size of the estuarine habitat. This information on habitat selection will be critical to planning future restorations on the Southern California coast
Endlicher and Sequoia: Determination of the Entymological Origin of the Taxon Sequoia
Full text linkThe genus Sequoia owes its taxonomic identity to Austrian botanist Stephen L. Endlicher. Research of primary material in Vienna and other locations have revealed Endlicher as a gifted linguist and botanist, who corresponded and interacted with colleagues throughout the world. These included persons who were experts on the Cherokee language and the person Sequoyah. Endlicher’s botanical work of creating eponymous taxa combined with his knowledge of the person Sequoyah throws new light on the origin of the genus Sequoia
Rules for Resistors: A Comparative Analysis of the Working Families Party and Tea Party
No full textThis paper will examine how third party efforts can gain influence in politics to make American democracy more representative. It will answer the question: how can third party efforts build political power at the federal, state, and local level? Data was collected through interviews with current staff of the Working Families Party and former staff of a Tea Party organization, FreedomWorks. The two organizations share many striking similarities despite their political differences. These similarities include: cultivating organizational and individual membership, budgets in the tens of millions of dollars, organizing around issue and electoral campaigns, focusing on economic issues, training members, and the goal of pushing the mainstream parties they operate within to represent the values they claim to represent by electing their own candidates. The analysis found that these two groups both represent a renewal in making government accountable to the people through active democratic participation and that they utilize populist resentment of the two mainstream political parties. It is recommended that third party efforts seek to reform policies that create obstacles for their participation, while mostly working within and around the existing two party system. It is also recommended that third party efforts take active steps to maintain their political independence, continue to utilize public opinion in their favor, cultivate individual grassroots members and create leadership structures around them, and seek new funding sources.
Distribution of the Eastern Fox Squirrel (Sciurus niger) within California as of 2015
Full text linkAbstract - The eastern fox squirrel, Sciurus niger, has been introduced to many areas outside of its native range. Once introduced to a new region the species has generally expanded its geographic range and is considered to be an invasive species, causing both ecological and economic harm. While some information is available on where introductions have occurred, detailed information is not available on the current geographic distribution of the species within California. Since invasive species tend to be under-represented in specimen collections at museums, new methods for obtaining location data were needed. We used a time period of 1995 through 2015 for observations so that location data would be most up-to-date. A majority (51%) of location data used in this study came from wildlife rehabilitation centers, approximately 31% came from citizen-science type sources such as the California Road-Kill Observation System, a previously published journal article, and research-grade submissions to iNaturalist, 10% came from the California Department of Public Health West Nile Virus Surveillance Program, and 8% came from the authors and trained student observers. Maps are presented to show the current geographic distribution of the species indicating a broader range than what was previously known
Habitat use and behavior of the east Pacific green turtle, Chelonia mydas in an urbanized system
Full text linkGreen sea turtles, Chelonia mydas, are known to inhabit populated and often urbanized areas. To understand turtle habitat use and behavior within these unique habitats, seven juvenile green turtles were fitted with acoustic transmitters (September 2012 – August 2014), of which two transmitters included an accelerometer (AP transmitter). One individual fitted with an AP transmitter was tracked using a passive acoustic array in an urbanized river, the San Gabriel River, Long Beach, CA (33°45’ N, 118°05’ W). Three additional turtles in this river and three turtles (one with AP transmitter) in a restored estuary (33°44’ N, 118°03’ W) in southern California were actively tracked for two non-consecutive 24-h periods. Those fitted with AP transmitters indicated that turtles were less active at night (0.58 ± 0.56 m/s2 and 0.50 ± 0.63 m/s2) than during the day (0.86 ± 0.63 m/s2 and 0.78 ± 0.60 m/s2) at both sites. Activity data and corresponding movements of the actively tracked turtle fitted with the AP transmitter were used to infer resting periods for other tracked individuals. Turtles rested near bridge pilings and runoff outflows in the river to potentially shelter from tidal flow. Turtles used significantly larger daily areas in the urbanized river (0.046 ± 0.023 km2) where resources may be patchier and less abundant, compared to turtles in the estuary (0.024 ± 0.012 km2) where large, dense eelgrass beds are present. Based on the habitat use and behaviors of green sea turtles, it appears that some green sea turtles are able to make use of both highly developed and restored habitats and likely benefit from certain aspects of development