Life Sciences Commons^™

Jeweled Spider Flies (Eulonchus Tristis) Are Important Pollinators Of Iris Bracteata, A Rare Siskiyou Mountain Endemic, Jean-Paul E. Ponte

Cal Poly Humboldt theses and projects

Little is known about the pollination biology of the Pacific Coast Irises (Iris: series Californicae, hereafter PCI), especially who visits and pollinates their flowers. In general, Iris flowers are considered bee-pollinated, however, flies in the genus Eulonchus (Acroceridae) are known to visit some PCI members. Therefore, I assessed the relative importance of Eulonchus and other insect visitors to the pollination of a rare PCI species native to the Siskiyou Mountains, I. bracteata.

Methods. I quantified pollinator importance for all flower visitors at sites in northern California and southern Oregon as the product of average visit rate and …

The Ability Of Phyllospadix Spp., A Pair Of Intertidal Foundation Species, To Maintain Biodiversity And Ameliorate Co2 Stress In Rocky Shore Tidepools, Tayler M. Tharaldson

Cal Poly Humboldt theses and projects

Ocean acidification (OA) is often demonstrated to have negative effects on marine organisms, but less is known about whether marine organisms can mediate OA effects. I examined relationships between surfgrass (Phyllospadix spp.), a foundation species and tidepool biodiversity, and its ability to mediate fluctuations in pH and dissolved oxygen (OA; DO) which are stressors in tidepools. I surveyed tidepools in northern California, where I quantified biodiversity, pH, and DO, and related those variables to surfgrass abundance. Laboratory and field experiments manipulating CO₂ and surfgrass presence were done to examine surfgrass effects on day/night pH and DO fluctuations …

Western Snowy Plover Nest Survival In Humboldt County, California, Katelyn M. Raby

Cal Poly Humboldt theses and projects

Productivity measures, such as nest survival, are often used to indirectly assess habitat quality and guide targeted management practices for the conservation of threatened and endangered species. The coastal population of the Western Snowy Plover (Charadrius nivosus nivosus) is listed as threatened due to three limiting factors: human disturbance, loss and degradation of habitat as a result of invasive plants, and increasing predator populations. I examined the relative influence of these three limiting factors on nest survival, using data from 2004 to 2017 at eight sites in Humboldt County, California. I assigned nests (n = 610) to three …

The Effects Of Ocean Acidification And Reduced Oxygen On The Behavior And Physiology Of Juvenile Rockfish, Corianna H. Flannery

Cal Poly Humboldt theses and projects

As climate change progresses, the frequency and duration of upwelling events that bring low pH, low dissolved oxygen (DO) water to nearshore habitats are expected to increase. In addition, long-term global changes in ocean pH and DO are expected to occur within the next few decades to centuries. Locally, there have been documented reductions in near-shore pH along with the expansion of oxygen minimum zones within the California Current System. However, very few studies have investigated the potential interactive effect of these stressors on temperate reef fish. For this thesis, two sets of laboratory experiments were conducted to determine the …

Predictive Mapping Of Two Nearshore, Demersal Fish Species On Northern California Reefs Using Scuba-Based Visual Surveys And Remote Sensing, Christopher H. Teague

Cal Poly Humboldt theses and projects

California's shallow rocky reefs provide critical habitat for a diverse assemblage of fishes. Effective management strategies for these species require both accurate stock assessments as well as a spatially explicit understanding of the relationship between fishes and characteristics of their habitat. We used a generalized additive model framework to create spatially predictive maps of the abundance and biomass of two demersal fish species prevalent on northern California reefs: lingcod (Ophiodon elongatus) and kelp greenling (Hexagrammos decagrammus). These models incorporated data from SCUBA-based fish and habitat surveys at depths from 12-26 meters as well as measures of …