Marine Biology Commons^™

Effects Of Ph, Eelgrass, And Settlement Substrate On The Growth Of Juvenile Magallana (Crassostrea) Gigas, A Commercially Important Oyster Species, Johnny S. Roche

Cal Poly Humboldt theses and projects

Worsening ocean acidification (OA), resulting from ongoing absorption of atmospheric carbon dioxide (CO₂) by the oceans, threatens marine life globally. Calcifying organisms, especially their early life stages, are particularly vulnerable; this includes the economically important Pacific oyster, Magallana (Crassostrea) gigas. Uptake of dissolved CO₂ through photosynthesis by seagrasses, like eelgrass (Zostera marina), may benefit calcifying organisms by increasing pH and carbonate availability. I conducted laboratory and field experiments to quantify carbonate chemistry modification by eelgrass and potential mitigation of OA impacts on growth in juvenile Pacific oysters. In the laboratory experiment, daytime …

Validation Of Pilot Protocol: Damage Scoring Of Puget Sound Mollusk Shells, Lauren Doffing

Environmental Science Undergraduate Theses

The Marine Sediment Monitoring Team at the Washington State Department of Ecology observed damage to mollusk shells while studying the benthic communities of Puget Sound. A pilot protocol was written to allow researchers to quantify the damage. Two researchers independently followed the protocol, including reference photos, for a set of samples collected in 2019 from an urban bay, East Possession Sound. Two scores were given to each specimen: highest-level damage and extent of highest-level damage. An additional score was given to bivalve species: rust/stain. The sets of scores were compared to determine if the protocol yielded similar values between the …

The Role Of Symbiotic Algae In The Acclimatization Of Oculina Arbuscula To Ocean Acidification, Erin M. Arneson

Electronic Theses and Dissertations

Ocean acidification (OA) caused by CO₂ emissions is projected to decrease seawater pH to 7.6 by 2100. Scleractinian corals are at risk because excess H⁺ in seawater binds to carbonate (CO₃^2-), reducing its availability for CaCO₃ skeletons. The energy demand for skeletal growth increases as pH decreases because corals must actively purge excess H⁺ from their seawater sourced calcifying fluid to maintain high calcification rates. In scleractinian corals it is hypothesized that photosynthesis by symbiotic algae is critical to meet this increased energy demand. To test this hypothesis, I conducted laboratory and field …

The Effects Of Ocean Acidification On The Gametogenesis Of The Red Tree Coral, Primnoa Pacifica, Ashley Rossin

Electronic Theses and Dissertations

Primnoa pacifica, otherwise known as the Red Tree Coral, is one of the most ecologically important corals in the North Pacific. This species is an ecosystem engineer, providing essential habitat for commercially important fish and invertebrate species. Ocean acidification (OA) threatens corals and all calcifying organisms and is more prevalent in polar and sub-polar regions as the concentration of CO₂ is higher and there is a lowered buffering capacity due to low alkalinity in colder waters. The impact from a chemical shift in the oceans could alter the role of P. pacifica as an ecosystem engineer in predicted ocean …

An Investigation Into The Physiological Impacts Of Ocean Acidification On Recruits Of The Temperate Coral, Oculina Arbuscula, Brianne Varnerin

Electronic Theses and Dissertations

Ocean acidification is well-researched with respect to adult scleractinian corals, however information on whether adults and recruits of the same species respond similarly to this environmental stress is lacking. I investigated the responses to increased pCO₂ of recruits of the temperate coral, Oculina arbuscula, whose adults are known to withstand high levels of pCO₂ with no depression in calcification (up to 1000 ppm CO₂). I addressed the hypothesis that O. arbuscula recruit health is not affected by increased pCO₂ by exposing small colonies (5-12mm diameter) to 475, 711, and 1270 ppm CO₂ for …

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 …

The Interactive Effects Of Ocean Acidification, Food Availability, And Source Location On The Growth And Physiology Of The California Mussel, Tharadet Daniel Man

Cal Poly Humboldt theses and projects

Research shows ocean acidification (OA) can have largely negative impacts on marine organisms and ecosystems. Prior laboratory studies show that shelled marine invertebrates (e.g., molluscs) exhibit reduced growth rates and weaker shells when experiencing OA-related stress. However, populations of the critical intertidal mussel species, Mytilus californianus, which experience naturally acidic water due to upwelling in certain parts of Northern California have been observed to have relatively stronger and thicker shells and higher growth rates than those that experience less frequent exposure to upwelling. To address the discrepancies between negative effects of OA exposure in the laboratory and seemingly positive …

Saving The Planet Begins With Saving The Coral Reefs, Marla Maconochie

Honors Projects

This honors project uses a children’s book format to aid in explaining the importance of saving the coral reefs. This book will be informing the younger generations about important, yet complicated issues at hand in a way that they can understand and relate to. The book explains how coral reefs are important for oxygen production, biodiversity, research opportunities, protection of coastal environments and for the economy. The children’s book explains how human activities and natural stressors can impact coral survivorship. The book explains how overfishing allows for excessive algal growth that smothers corals and tackles how coral bleaching occurs and …

Effects Of Ocean Warming And Acidification On Fertilization Success And Early Larval Development In The Green Sea Urchin, Lytechinus Variegatus, Brittney L. Lenz

HCNSO Student Theses and Dissertations

Climate change is predicted to affect the larval stages of many marine organisms. Ocean warming can reduce larval survival and hasten larval development, whereas ocean acidification can delay larval development. Ocean acidification is especially concerning for marine organisms that develop and grow calcified shells or skeletons in an environment undersaturated with calcium carbonate minerals. This study assessed the effects of ocean warming and acidification on the fertilization and larval development of the green sea urchin, Lytechinus variegatus, a tropical species common in Florida and the Caribbean. After spawning, gametes were fertilized and embryos/larvae were reared at: 1) 28°C and …

Investigating The Effects Of Decreased Ph On The Intertidal Shore Crab, Hemigrapsus Nudus, Avni Gandhi

Honors Theses

Ocean acidification has emerged as an issue for marine organisms, due to increased levels of CO2 in the atmosphere. In particular, invertebrates with calcium carbonate exoskeletons seem to be at risk. Our research investigates the potential effect of decreased pH on the weight of Hemigrapsus nudus, a species of intertidal crab found in Northern California. Over a 6 week period, crabs were maintained in individual containers with recirculating chilled seawater at 12.7°C. The control aquaria was maintained at 8.1 pH, while the experimental aquaria averaged a pH of 7.5. Crabs were weighed at two week intervals, preliminary information shows the …

Linking Rising Pco2 And Temperature To The Larval Development, Physiology And Gene Expression Of The American Lobster (Homarus Americanus), Jesica Waller

Electronic Theses and Dissertations

Anthropogenic warming and ocean acidification are occurring as CO₂ continues to accumulate in the atmosphere (OA). Few studies have evaluated the joint effects of elevated temperature and partial pressure of CO₂ (pCO₂)on marine organisms. In this study we investigated the interactive effects of Intergovernmental Panel on Climate Change (IPCC) predicted temperature and pCO₂ for the end of the 21st century on key aspects of larval development of the American lobster, Homarus americanus, an otherwise well-studied, iconic, and commercially prominent species in the northeastern United States and Atlantic Canada. Our experiments showed …

Multi-Stress Proteomics: The Global Protein Response To Multiple Environmental Stressors In The Porcelain Crab Petrolisthes Cinctipes, Michael A. Garland

Master's Theses

Global climate change is increasing the number of hot days along the California coast as well as increasing the incidence of off-shore upwelling events that lower the pH of intertidal seawater; thus, intertidal organisms are experiencing an increase in more than one stress simultaneously. This study seeks to characterize the global protein response of the eurythermal porcelain crab Petrolisthes cinctipes to changes in thermal, pH, and tidal regime treatments, either combined or individually. The first experiment examined temperature stress alone and sought to determine the effect of chronic temperature acclimation on the acute heat shock response. We compared the proteomic …

Growth Of The Marine Fish-Killing Phytoflagellate, Heterosigma Akashiwo Under Emerging Coastal Regimes: Temperature, Eutrophication And Ocean Acidification, Cayla M. Bronicheski

Electronic Thesis and Dissertation Repository

Coastal oceans are fundamental to human economies, nutrition and recreation. Anthropogenic stressors have led to the acceleration of the nitrogen cycle, the accumulation of inorganic carbon in the earth’s atmosphere, the loss of UV-scavenging upper atmospheric ozone and the overall accumulation of deep elements from the earth’s crust to surface exposure. These changes have caused ocean acidification and eutrophication events in coastal waters and the impacts of these events on primary production and ocean biodiversity are not yet fully understood.

This study examined the effects of predicted future ocean conditions (salinity, temperature, reduced seawater pH and modified nitrogen supplies), on …