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These supplementary teaching resources align to the open textbook, Fish, Fishing, and Conservation which is a 389-page, peer-reviewed publicly-available, openly-licensed textbook intended for undergraduate students who are exploring majors in Fish & Wildlife. It is also relevant to a general audience or for use in courses which explore social and ethical aspects of fish, fishing and conservation. The open textbook, Fish, Fishing, and Conservation, is freely available at https://doi.org/10.21061/fishandconservation Supplementary teaching resources include a sample course syllabus, schedule, and a variety of assignments. Individuals who wish to share their materials relevant to teaching in this subject area are encouraged to join and share their openly-licensed resources via the Fish, Fishing, and Conservation Instructor Group in OERCommons Are you reviewing or adopting Fish, Fishing, and Conservation for a course? Please help us understand your use by completing this form https://bit.ly/fishandconservation_interest VIVA (Virtual Library of Virginia)

The creation, movement, and consumption of distinct biomolecules by marine organisms has far reaching implications regarding ecosystem material and energy flow and how we manage the marine environment. Lipids are ubiquitous, energy rich biomolecules that are essential for all life and are used for cell membrane structure, energy storage and serve as useful indicators for ecosystem and food web dynamics. In this dissertation, the flow of specific lipid biomolecules through multiple marine environments is measured, explored, and clarified to better understand biogeochemical cycles, marine food webs and ecosystem connectivity. In the first chapter of my dissertation, I measure, quantify, and close the loop of the open ocean microbial hydrocarbon cycle, with implications for priming effects of the ocean microbiome to oil spills. It is estimated that seeps, spills, and other oil pollution introduce ~ 1.3 million tons (1.3 Tg) of hydrocarbons into the ocean each year. Additionally, it is known that globally abundant marine cyanobacteria Prochlorococcus and Synechococcus which account for ~25% of ocean net primary production also produce hydrocarbons from fatty acids. But little is known about the size, turnover and fate of these cyanobacterial hydrocarbons and the implications for the ocean’s microbiome response to future oil spills. From a research expedition in the North Atlantic, I report that cyanobacteria in an oligotrophic gyre mainly produce n-pentadecane which correlates tightly with fluorescence and Prochlorococcus abundance in oligotrophic waters. Using chemical and isotopic tracing I find that pentadecane production and diel dynamics mainly occurs in the lower euphotic zone at the deep chlorophyll maximum. I estimate the global flux of cyanobacteria-produced pentadecane exceeds total oil input in the ocean by 100 to 500-fold, with cyanobacteria producing ~ 130-650 million tons of pentadecane per year. Analysis of sinking particles at the base of the euphotic zone show that nearly all pentadecane (< 0.001 % remaining) is consumed within the euphotic zone, suggesting near complete consumption of these hydrocarbons by hydrocarbon degrading microbes. These findings characterize a wide-spread microbial hydrocarbon cycle that selectively primes the ocean’s microbiome with long-chain alkanes. In the second chapter of my dissertation, I conduct a large-scale feeding experiment on a symbiotic reef-building coral (Stylophora pistillata) in the Red Sea to clarify fatty acid and isotopic biomarker patterns of coral heterotrophy for use in the field. Coral heterotrophy is an often-overlooked facet of coral nutrition that provides essential nutrients that help corals resist and recover from thermally induced bleaching that is degrading reef ecosystems around the world due to rising global ocean temperatures. Yet, methods for measuring coral mixotrophy, the balance between organic matter contributions to the coral host from autotrophic photo endosymbionts and heterotrophy on particles and plankton have typically been too coarse to elucidate source contributions. Through my experiment I show that fatty acids and isotopic biomarkers reliably separate experimental and reef nutritional source groups (heterotrophic or autotrophic). I show that heterotrophic fatty acid biomarkers are reliably recorded into coral host and symbiont tissues, with a divergent metabolic pattern of autotrophic biomarkers as feeding increases due to positive feedback of heterotrophy on the in hospite photo symbiont population. Additionally, I show that nitrogen and essential fatty acids are preferentially recorded into coral tissue while most heterotrophic carbon is respired or exuded as mucous; this shows that the use of bulk carbon isotopes as a feeding proxy for the last ~ 40 years is largely underestimating the contribution of heterotrophy to the trophic ecology of reef building corals. Overall, this finding underscores a connectivity between oceanic phyto- and zooplankton and reef-building coral. In the third chapter of my dissertation, I explore the mixotrophic differences of divergent bleaching responses of Acropora hyacinthus colonies on the forereef of Mo’orea during the 2019 mass bleaching event. During this bleaching event, all colonies of A. hyacinthus on the deep forereef (14 m) bleached and recovered, while colonies on the shallow forereef (5 m) near the reef crest resisted bleaching entirely, despite the same temperature stress. Using fatty acid and isotopic biomarkers I show through several lines of evidence that bleaching resistant colonies near the reef crest were likely consuming more particulate organic matter than deep forereef colonies. This conclusion is supported by isotopic feeding proxies, less isotopic niche overlap of the host and symbiont of resistant colonies, and larger proportions of putative POM fatty acid biomarkers in the host of resistant colonies relative to recovered colonies. This interpretation is in line with observations that benthic communities on the reef crest are a net sink of oceanic POM and that increased reliance on heterotrophy is associated with bleaching resistance. These data show the vital importance of reef environment, coral heterotrophy, and planktonic subsidies in structuring bleaching response of corals in a warming ocean and ultimately show that the reef crest may serve as a potent zone for reseeding coral populations after marine heat waves.

Understanding what factors shape the magnitude of divergence under rapid evolution is critical. Phenotypic divergence, specifically, can be influenced by selective forces such as the environment (climate, geographic distance) as well as non-selective forces (genetic composition of the founding population). Threespine sticklebacks provide a unique opportunity to study the magnitude of divergence under rapid evolution. Marine sticklebacks independently colonized freshwater habitats at the end of the last ice age (~12,000 years ago) generating multiple replicate pairs that represent a natural experiment. However, studies rely on untested assumptions that marine sticklebacks are not phenotypically varied and are unchanged from their ancestors. Here, we test how differential environmental conditions impact the estimated magnitude of phenotypic divergence and parallelism of independent freshwater stickleback populations. We find that marine variation is comparable to freshwater variation. Importantly, the inferred magnitude of phenotypic divergence of each freshwater population is dependent on marine sampling location. The geographic distance and environmental similarity between the marine and freshwater pairs explain a significant degree of variance. When estimating the degree of parallelism among freshwater pairs, marine reference also affects the inferred magnitude. The observed pattern suggests the choice of reference population and its geographic distance are important aspects to consider when estimating freshwater divergence and parallelism. Results also implicate a signature of local adaptation and/or isolation by distance. We provide recommendations for choosing ecologically relevant marine references in future studies on this important evolutionary model system.

Widespread overuse and large-scale production of antibiotics create antibiotic pollution, disrupting environmental microbiota and creating a public health risk. Highly urbanized coastal environments can be under high impact from antibiotic pollution from many trails of polluted effluents and runoff. The city of Long Beach is one such coastal area under high impact, since it is highly urban, industrialized, and experiences frequent sewage spills. We collected water samples from the LA River in a transect running southwest into the San Pedro Channel in order to investigate (1) how does strength of antibiotic resistance change as distance from shore increases, and (2) does antibiotic resistance correlate with composition of the bacterial community. There was no consistent relationship between strength of antibiotic resistance and distance from shore. Instead, we found that bacteria from the Pacific Ocean showed higher antibiotic resistance than bacteria from the LA River in five out of eleven antibiotic treatments. We also found that the alpha diversity of bacterial communities was lower in the LA River samples compared, and alpha diversity positively correlated with strength of antibiotic resistance in four antibiotic treatments. Our findings highlight how prevalence of antibiotic pollution does not always follow a distance dilution, as well as the need for understanding the strength behind antibiotic resistance in marine bacteria.

Marine Protected Areas (MPAs) have been implemented worldwide as a tool for improving the overall health and function of fisheries and marine ecosystems impacted by fishing activity. Monitoring the performance of MPAs in a comprehensive way is crucial for the effective management and thoughtful implementation of new MPAs. In California, mesophotic (30-100m) rocky reef fish communities are a valuable commercial/recreational resource, though the effects of MPAs on this community remain relatively understudied. This is at least partially a result of depth restricted sampling tools that do not typically overlap; SCUBA surveys are generally limited to shallow depths (<30 m) and Remotely Operated Vehicle/Autonomous Underwater Vehicle surveys are often used for deep water (>100m). Additionally, traditional extractive techniques like trawl surveys are limited by their inability to effectively sample high relief rocky habitats, and are not commonly used in MPAs due to their destructive nature. With this study we tested the effects of two MPAs on demersal fish communities living on mesophotic rocky reefs utilizing Baited Remove Underwater Video (BRUV) surveys. We deployed BRUV landers annually from 2019 to 2021 at Anacapa State Marine Reserve/State Marine Conservation Area (SMR/SMCA) and Carrington Pt. SMR. We observed significant positive reserve effects on the total biomass of targeted (i.e., fished) species and on the size structure of individual focal species at both study sites. Relative abundance (MaxN) proved to be a less sensitive metric than biomass for detecting MPA effects, underscoring the utility of a stereo-video camera system that is capable of capturing highly accurate fish measurements. Dissimilar rocky habitat abundance for the deepest depth zones at Anacapa Island, where rockfish (Sebastes spp.) represent the largest proportion of the fish community, is likely one explanation for the negative reserve effect we observed for targeted rockfish abundance at this site. The results of this study provide useful information on how two California MPAs affect valuable fish communities that have historically been understudied and emphasize the importance of accurate fish measurement to detect these effects. This work also highlights the significance of habitat availability on the distribution of species with high habitat affinity. The continued monitoring of demersal fish communities on mesophotic rocky reefs would provide resource managers a more comprehensive understanding of MPA performance in California.

The surface temperature in the Arctic has warmed at twice the rate of the global mean temperature during recent decades. This Arctic amplification of global warming has been a striking feature of climate change, and many studies have investigated what processes contribute to this phenomenon. Many of these processes are often described in the context of climate feedbacks using analyses focused on top-of-the-atmosphere radiative changes. In this context, regional surface warming can then be partitioned into contributions from each feedback process. However, this partitioning can be complicated by interactions between feedbacks themselves and atmospheric heat transport. In the second chapter, we instead apply a feedback-locking approach and evaluate the resulting changes in surface temperature. These results are strikingly different from previous feedback analyses, highlighting the important role of interactions within the climate system. This chapter and many other previous studies focus only on the role of atmospheric and surface processes in Arctic amplification. However, substantial questions remain regarding the role of ocean heat transport. In the third chapter, we investigate changes in oceanic heat fluxes under global warming. We find a mechanism associated with the presence of sea ice that drives enhanced horizontal ocean heat transport into the Arctic region and can contribute substantially to Arctic amplification if this heat is allowed to reach the surface. Currently, only a small amount of the heat stored at depth in the Arctic Ocean can reach the surface, but recent observational studies have argued that sea ice retreat could result in enhanced vertical mixing. In the fourth chapter, we investigate the impacts of a positive feedback whereby increased vertical mixing due to sea ice retreat causes the previously isolated subsurface Arctic Ocean heat to melt more sea ice. We find that an abrupt “tipping point” can occur under global warming, with an associated hysteresis window, for a limited range of parameters. Throughout the thesis, we use idealized models to show how ocean and climate processes can impact Arctic warming, providing insights into possible physical mechanisms that could be at play now or in the future.

Time and energy are finite resources in any environment, and how and when organisms use their available resources to survive and reproduce is the crux of life history theory (Gadgil and Bossert 1970; Balon 1975; Stearns 1976). The different survival strategies used by animals are often shaped by their environment in addition to their biology (Winemiller and Rose 1992), which allows for exploration into biological variability when environmental factors are known. For this reason, the Line Islands in the Central Pacific provide an ideal location to perform observational studies due to their unique productivity gradient and fish assemblage structures across the island chain (Sandin et al. 2008; DeMartini et al. 2008; Fox et al. 2018; Zgliczynski et al. 2019). Many of the world’s coral reefs are in remote regions that lack monitoring programs or even local populations, so conducting ecological surveys on fish communities in these regions can require extensive amounts of time, energy, resources and people. The inherent variability an environment exerts on the many factors that contribute to growth over a lifetime make it difficult to generate a directly proportional formula that calculates age. A novel age estimation method was developed that utilizes in-situ visual census data to estimate the age of fishes, and as a case study, several fish were chosen as representative species to explore its capabilities. Through this process, new ecological information and insight can be gained about the age structures of fish populations both between and throughout the Line Islands.

Understanding fish diversity patterns is critical for fisheries management amidst overfishing and climate change. Fish egg surveys have been used to characterize pelagic spawning fish communities, estimate biomass, and track population trends in response to perturbations. Environmental DNA (eDNA) metabarcoding has been implemented to rapidly and non-invasively survey marine ecosystems. To understand the efficacy of eDNA metabarcoding for assessing pelagic spawning fish community composition, concurrent eDNA metabarcoding and fish egg DNA barcoding off Scripps Institution of Oceanography’s Pier (La Jolla, CA) were conducted. Both methods revealed seasonal patterns in agreement with previous fish and fish egg surveys. Species richness was highest in late spring and summer. The presence and spawning of commercially important species and species of conservation concern were detected. Both methods showed overlap for pelagic spawning fishes for broadcast spawners, schooling fish, and locally abundant species. Some actively spawning species were not co-detected with eDNA, likely due to different sampling strategies, taxonomic biases, and abiotic/biotic factors influencing eDNA transport, shedding, and degradation. We identified key advantages and disadvantages of each method. Fish egg barcoding provided information on spawning trends but did not detect taxa with alternate reproduction strategies. Metabarcoding eDNA detected species not found in fish egg sampling, including demersal and viviparous bony fishes, non-spawning adults, Chondrichthyan, and Mammalian species, but missed abundant pelagic fish eggs. This study demonstrates that DNA barcoding of fish eggs and eDNA metabarcoding work best in tandem as each method identified unique fish taxa and provided complementary ecological and biological insight.

The western North Atlantic is a dynamic region characterized by the Gulf Stream western boundary current and inhabited by a diverse host of odontocete, or toothed whale, top predators. Their habitats are highly exploited by commercial fisheries, shipping, marine energy extraction, and naval exercises, subjecting them to a variety of potentially harmful interactions. Many of these species remain poorly understood due to the difficulties of observing them in the pelagic environment. Their habitat utilization and the impacts of anthropogenic activities are not well known. Over the past decade, passive acoustic data has become increasingly utilized for the study of a wide variety of marine animals, and offers several advantages over traditional line-transect visual survey methods. Passive acoustic devices can be deployed at offshore monitoring sites for long periods of time, enabling detection of even rare and cryptic species across seasons and sea states, and without altering animal behaviors. Here we utilized a large passive acoustic data set collected across a latitudinal habitat gradient in the western North Atlantic to address fundamental knowledge gaps in odontocete ecology. I approached the problem of discriminating between species based on spectral and temporal features of echolocation clicks by using machine learning to identify novel click types, and then matching these click types to species using spatiotemporal correlates. I was able to identify novel click types associated with short-beaked common dolphins, Risso’s dolphins, and short-finned pilot whales in this way. Next I characterized temporal patterns in presence and activity for ten different species across our monitoring sites at three different temporal scales: seasonal, lunar, and diel. I observed spatiotemporal separation of apparent competitors, and complex behavioral patterns modulated by interactions between the seasonal, lunar, and diel cycles. Finally I investigated the relationships between species presence and oceanographic covariates to predict habitat suitability across the region, and explored niche partitioning between potentially competitive species. The insights gained here significantly advance our understanding of toothed whale ecology in this region, and can be used for more effective population assessments and management in the face of anthropogenic threats and climate change.

Amines were measured by aerosol mass spectrometry (AMS) and Fourier Transform Infrared (FTIR) spectroscopy during the North Atlantic Aerosols and Marine Ecosystems Study (NAAMES) cruises. Both AMS non-refractory (NR) amine ion fragments comprising the AMS CxHyNz family and FTIR non-volatile (NV) amine measured as primary (C-NH2) amine groups typically had greater concentrations in continental air masses than marine air masses. Secondary continental sources of AMS NR amine fragments were identified by consistent correlations to AMS NR nitrate, AMS NR m/z 44, IC non-sea salt potassium, and radon for most air masses. FTIR NV amine group mass concentrations for particles with diameters <1 μm showed large contributions from a primary marine source that was identified by significant correlations with measurements of wind speed, chlorophyll a, seawater dimethylsulfide (DMS), AMS NR chloride, and ion chromatography (IC) sea salt as well as FTIR NV alcohol groups in both marine and continental air masses. FTIR NV amine group mass concentrations in <0.18 μm and <0.5 μm particle samples in marine air masses likely have a biogenic secondary source associated with strong correlations to FTIR NV acid groups, which are not present for <1 μm particle samples. The average seasonal contribution of AMS NR amine fragments and FTIR NV amine groups ranged from 27% primary marine amine and 73% secondary continental amine during Early Spring to 53% primary amine and 47% secondary continental amine during Winter. These results demonstrate that AMS NR and FTIR NV amine measurements are complementary and can be used together to investigate the variety and sources of amines in the marine environment.