Graduate Recital: Matthew Boze

Kemp Recital HallMarch 31, 2012Saturday Afternoon4:30 p.m

The Influence of Message Type, Environmental Attitude, and Political Ideology on Perceptions of Aquaculture in the United States

In the United States, aquaculture receives varying degrees of support based on individuals’ perceptions of the industry. This study analyzes the factors that contribute to those perceptions; namely, message type, affect, political orientation, and environmental attitude. We collected data through a nationwide survey, distributed by Qualtrics, which recruited a representative sample of U.S. residents. The survey included multiple-choice, Likert scale, and open-ended questions regarding individual characteristics (e.g., age, income, political orientation, etc.) and opinions on aquaculture. In order to study message type, we employed four experimental conditions (narrative video, narrative text, infographic video, and text) and one control group with no message. Affect was measured using the Linguistic Inquiry and Word Count (LIWC) software program. Finally, environmental attitude was determined using Dunlap et al.’s (2000) 15-item version of the New Environmental Paradigm (NEP). Results from this study suggest that the infographic and narrative video were most effective in eliciting responses regarding perceived benefits of aquaculture. We found that the control group had the lowest rates of aquaculture benefit responses, indicating that it is better to use some sort of stimuli than none at all. Mirroring findings from previous research on aquaculture perceptions (Feucht & Zander, 2015; Freeman et al., 2012; Rickard et al., 2018; Rickard et al., 2020; Schlag & Ystgaard, 2013; Vanhonacker et al., 2011), we also found these results to be an indicator of individuals’ generally low level of awareness and knowledge surrounding aquaculture. Additionally, findings suggest that the narrative video was somewhat off-putting to participants, as there were increased rates of negative emotion among those who watched the narrative video. Lastly, results showed that an individual’s environmental attitude is associated with a greater likelihood of mentioning general aquaculture benefits, as well as environmental benefits. Alternatively, findings indicate that political ideology does not predict an individual’s views on aquaculture– which we speculate might be due to aquaculture not yet having gained the same degree of politicization as other environmental issues in the public sphere within the U.S. (e.g., climate change). Looking forward, these findings could encourage aquaculture advocates to gear outreach efforts toward individuals with higher environmental-consciousness and be further encouraged in their efforts, as perceptions do not appear to be politically saturated. Researchers might further investigate the influence of message type by employing more conditions with varying length, message, and speaker. Future research might also employ path analysis to explore how perceptions of aquaculture are influenced by different message types, political orientation, and environmental attitude, in both direct and indirect ways. Overall, this work contributes to a more holistic understanding of the public’s perceptions of aquaculture and in turn, informs more effective communication efforts with increased information salience and ideally, support for sustainable aquaculture

Student Ensemble: Percussion Ensemble

Kemp Recital HallNovember 6, 2011Sunday Evening7:00 p.m

A review of how we assess denitrification in oyster habitats and proposed guidelines for future studies

Excess nitrogen (N) loading and resulting eutrophication plague coastal ecosystems globally. Much work is being done to remove N before it enters coastal receiving waters, yet these efforts are not enough. Novel techniques to remove N from within the coastal ecosystem are now being explored. One of these techniques involves using oysters and their habitats to remove N via denitrification. There is substantial interest in incorporating oyster-mediated enhancement of benthic denitrification into N management plans and trading schemes. Measuring denitrification, however, is expensive and time consuming. For large-scale adoption of oyster-mediated denitrification into nutrient management plans, we need an accurate model that can be applied across ecosystems. Despite significant effort to measure and report rates of denitrification in oyster habitats, we are unable to create such a model, due to methodological differences between studies, incomplete data reporting, and inconsistent measurements of environmental variables that may be used to predict denitrification. To make a model that can predict denitrification in oyster habitats a reality, a common sampling and reporting scheme is needed across studies. Here, we provide relevant background on how oysters may stimulate denitrification, and the importance of oyster-mediated denitrification in remediating excess N loading to coastal systems. We then summarize methods commonly used to measure denitrification in oyster habitats, discuss the importance of various environmental variables that may be useful for predicting denitrification, and present a set of guidelines for measuring denitrification in oyster habitats, allowing development of models to support incorporation of oyster-mediated denitrification into future policy decisions

Facilitating better outcomes: how positive species interactions can improve oyster reef restoration

Over 85% of the world's oyster reefs have been lost in the past two centuries, triggering a global effort to restore shellfish reef ecosystems and the ecosystem services they provide. While there has been considerable success in re-establishing oyster reefs, many challenges remain. These include: high incidence of failed restoration, high cost of restoration per unit area, and increasing stress from climate change. In order to leverage our past successes and progress the field, we must increase restoration efficiencies that not only reduce cost per unit area, but also increase the resilience of restored ecosystems. To help address this need, we qualitatively review the literature associated with the structure and function of oyster reef ecosystems to identify key positive species interactions (i.e., those species interactions where at least one partner benefits and no partners are harmed). We classified positive inter- and intraspecific interactions between oysters and organisms associated with oyster ecosystems into the following seven functional categories: (1) physical reef creation, (2) positive density dependence, (3) refugia from physical stress, (4) refugia from biological stress, (5) biodiversity enhancement, (6) settlement improvement, and (7) long-distance facilitation. We discuss each category of positive interaction and how restoration practitioners can use knowledge of such processes to enhance restoration success. We propose that systematic incorporation of positive species interactions into restoration practice will both enhance ecological services provided by restored reefs and increase restoration success

Oyster reef restoration fails to recoup global historic ecosystem losses despite substantial biodiversity gain

Human activities have led to degradation of ecosystems globally. The lost ecosystem functions and services accumulate from the time of disturbance to the full recovery of the ecosystem and can be quantified as a “recovery debt,” providing a valuable tool to develop better restoration practices that accelerate recovery and limit losses. Here, we quantified the recovery of faunal biodiversity and abundance toward a predisturbed state following structural restoration of oyster habitats globally. We found that while restoration initiates a rapid increase in biodiversity and abundance of reef-associated species within 2 years, recovery rate then decreases substantially, leaving a global shortfall in recovery of 35% below a predisturbed state. While efficient restoration methods boost recovery and minimize recovery shortfalls, the time to full recovery is yet to be quantified. Therefore, potential future coastal development should weigh up not only the instantaneous damage to ecosystem functions but also the potential for generational loss of services

Directly Measured Denitrification Reveals Oyster Aquaculture and Restored Oyster Reefs Remove Nitrogen at Comparable High Rates

Coastal systems are increasingly impacted by over-enrichment of nutrients, which has cascading effects for ecosystem functioning. Oyster restoration and aquaculture are both hypothesized to mitigate excessive nitrogen (N) loads via benthic denitrification. The degree to which these management activities perform similar functions for removing N, however, has not been extensively examined in New England, a place where nutrient runoff is high and increasing oyster (Crassostrea virginica) restoration and aquaculture activity is taking place. Here, we use a novel in situ methodology to directly measure net N2 and O2 fluxes across the sediment-water interface in a shallow (~1 m) coastal pond in southern Rhode Island. We collected data seasonally during 2013 and 2014 at restored oyster reefs, oyster aquaculture, oyster cultch (shell), and bare sediment. Restored oyster reefs and aquaculture had the highest mean (±SE) denitrification rates, 581.9 (±164.2) and 346 (±168.6) μmol N2−N m−2 h−1, respectively, and are among the highest recorded for oyster-dominated environments. Denitrification rates at sites with oyster cultch were 60.9 (±44.3) μmol N2−N m−2 h−1, which is substantially less than the sites with active oysters but still more than 50% higher than denitrification rates measured in bare sediment (24.4 ± 10.1 μmol N2–N m−2 h−1). The increase in denitrification rates at treatments, however, varied by season and the greatest rates for restored reefs were in the fall. Overall, the greatest aggregate denitrification rates occurred in the fall. Sediment oxygen demand (SOD) followed similar patterns but with greater overall rates in the summer, and displayed a strong linear relationship with denitrification (R2 = 0.93). Our results demonstrate that habitats associated with live oysters have higher net denitrification rates and that oyster reef restoration and oyster aquaculture may provide similar benefits to the ecosystem in terms of N removal. However, gas fluxes may also be affected where three-dimensional structure is introduced via oyster shell cultch and this appears to be seasonally-dependent. These data will be important for managers as they incorporate oysters into nutrient reduction strategies and consider system-level trade-offs in services provided by oyster reef restoration and aquaculture activities

Directly Measured Denitrification Reveals Oyster Aquaculture and Restored Oyster Reefs Remove Nitrogen at Comparable High Rates

Coastal systems are increasingly impacted by over-enrichment of nutrients, which has cascading effects for ecosystem functioning. Oyster restoration and aquaculture are both hypothesized to mitigate excessive nitrogen (N) loads via benthic denitrification. The degree to which these management activities perform similar functions for removing N, however, has not been extensively examined in New England, a place where nutrient runoff is high and increasing oyster (Crassostrea virginica) restoration and aquaculture activity is taking place. Here, we use a novel in situ methodology to directly measure net N2 and O2 fluxes across the sediment-water interface in a shallow (~1 m) coastal pond in southern Rhode Island. We collected data seasonally during 2013 and 2014 at restored oyster reefs, oyster aquaculture, oyster cultch (shell), and bare sediment. Restored oyster reefs and aquaculture had the highest mean (±SE) denitrification rates, 581.9 (±164.2) and 346 (±168.6) μmol N2−N m−2 h−1, respectively, and are among the highest recorded for oyster-dominated environments. Denitrification rates at sites with oyster cultch were 60.9 (±44.3) μmol N2−N m−2 h−1, which is substantially less than the sites with active oysters but still more than 50% higher than denitrification rates measured in bare sediment (24.4 ± 10.1 μmol N2–N m−2 h−1). The increase in denitrification rates at treatments, however, varied by season and the greatest rates for restored reefs were in the fall. Overall, the greatest aggregate denitrification rates occurred in the fall. Sediment oxygen demand (SOD) followed similar patterns but with greater overall rates in the summer, and displayed a strong linear relationship with denitrification (R2 = 0.93). Our results demonstrate that habitats associated with live oysters have higher net denitrification rates and that oyster reef restoration and oyster aquaculture may provide similar benefits to the ecosystem in terms of N removal. However, gas fluxes may also be affected where three-dimensional structure is introduced via oyster shell cultch and this appears to be seasonally-dependent. These data will be important for managers as they incorporate oysters into nutrient reduction strategies and consider system-level trade-offs in services provided by oyster reef restoration and aquaculture activities