Georgia Sea Grant

Abstract Climate change is altering naturally fluctuating environmental conditions in coastal and estuarine ecosystems across the globe. Departures from long-term averages and ranges of environmental variables are increasingly being observed as directional changes [e.g., rising sea levels, sea surface temperatures (SST)] and less predictable periodic cycles (e.g., Atlantic or Pacific decadal oscillations) and extremes (e.g., coastal flooding, marine heatwaves). Quantifying the short- and long-term impacts of climate change on tidal marsh seascape structure and function for nekton is a critical step toward fisheries conservation and management. The multiple stressor framework provides a promising approach for advancing integrative, cross-disciplinary research on tidal marshes and food web dynamics. It can be used to quantify climate change effects on and interactions between coastal oceans (e.g., SST, ocean currents, waves) and watersheds (e.g., precipitation, river flows), tidal marsh geomorphology (e.g., vegetation structure, elevation capital, sedimentation), and estuarine and coastal nekton (e.g., species distributions, life history adaptations, predator-prey dynamics). However, disentangling the cumulative impacts of multiple interacting stressors on tidal marshes, whether the effects are additive, synergistic, or antagonistic, and the time scales at which they occur, poses a significant research challenge. This perspective highlights the key physical and ecological processes affecting tidal marshes, with an emphasis on the trophic linkages between marsh production and estuarine and coastal nekton, recommended for consideration in future climate change studies. Such studies are urgently needed to understand climate change effects on tidal marshes now and into the future.

Salt marsh ecosystems and the seascapes in which they are embedded serve as critical habitats for species harvested by fisheries (1), which provide food and economic security for hundreds of millions of people (2). Historical marsh losses coupled with increasing pressures from coastal development and climate change place these intertidal ecosystems and surrounding uplands under growing threat (3). Preventing further losses of salt marshes and associated fisheries production will require greater public awareness and difficult choices in coastal policy and management, underpinned by greater understanding of marsh function.

Climate change has far-reaching effects on human and ecological systems, requiring collaboration across sectors and disciplines to determine effective responses. To inform regional responses to climate change, decision-makers need credible and relevant information representing a wide swath of knowledge and perspectives. The southeastern U. S. State of Georgia is a valuable focal area for study because it contains multiple ecological zones that vary greatly in land use and economic activities, and it is vulnerable to diverse climate change impacts. We identified 40 important research questions that, if answered, could lay the groundwork for effective, science-based climate action in Georgia. Top research priorities were identified through a broad solicitation of candidate research questions (180 were received). A group of experts across sectors and disciplines gathered for a workshop to categorize, prioritize, and filter the candidate questions, identify missing topics, and rewrite questions. Participants then collectively chose the 40 most important questions. This cross-sectoral effort ensured the inclusion of a diversity of topics and questions (e.g., coastal hazards, agricultural production, ecosystem functioning, urban infrastructure, and human health) likely to be important to Georgia policy-makers, practitioners, and scientists. Several cross-cutting themes emerged, including the need for long-term data collection and consideration of at-risk Georgia citizens and communities. Workshop participants defined effective responses as those that take economic cost, environmental impacts, and social justice into consideration. Our research highlights the importance of collaborators across disciplines and sectors, and discussing challenges and opportunities that will require transdisciplinary solutions.

future college graduates to be engaged, science-literate citizens. Yet data suggest that most college biology classes as currently taught do little to make science truly useful for students' lives and provide few opportunities for students to practice skills needed to be key decision makers in their communities. This is especially important for our non-science majors, as they represent the vast majority (82%) of college students. In this essay, we identify three critical aspects of useful college science education to prepare science literate non-science majors: prioritize local socioscientific issues; highlight communal opportunities in science that impact students' communities; and provide students with opportunities to practice skills necessary to engage with science beyond the classroom.

This chapter illustrates how three-dimensional (physical, chemical and biological) ecosystem models can help scientists and managers understand and predict the eutrophic impact of aquaculture for a specific embayment, as well as the interactions between two different types of aquaculture: shrimp and finfish culture, which depends on supplemental feeding; and the culture of bivalve molluscs and macroalgae, which extract plankton and nutrients from surrounding waters. Two case studies of the use of ecosystem models to evaluate the impacts of aquaculture are discussed. The first example describes conditions in Jiaozhou Bay in Shandong Province and the second describes Xincun Lagoon on Hainan Island, China.

Professional societies are critical agents of change for making the field of coastal and ocean sciences more diverse, equitable, inclusive, just, and accessible because their leadership and programming engage students, educators, researchers, and professionals in a range of sectors. Societies reach community members in academia, industry, nonprofit organizations, and government at all levels, and with geographic scope that ranges from local to international. Professional societies can act as standard setters for their disciplines, exemplifying and amplifying promising practices in the field, and assisting members with adopting these practices at their home institutions. The functions of professional societies can be parsed into categories that describe the unique ways they serve their memberships and their fields, all of which impact the professions’ cultures. In this paper, we assess the role of professional societies in advancing diversity, equity, inclusion, justice, and accessibility (DEIJA) in the field of ocean sciences across a range of societal functions. We also highlight some actions that coastal and ocean science-focused professional societies are taking to integrate DEIJA into each of their functions to improve the culture of ocean sciences.

Abstract The “Georgia Jumper” turtle excluder device (TED) is a rare example of a well-accepted conservation tool required by regulation. Mediated by the UGA Marine Extension and Georgia Sea Grant, Georgia's shrimping industry was integral to the design, revision, and implementation of excluder devices, since the earliest “jellyball shooter” proposed to NMFS in 1980. This paper highlights fisher involvement in the creation of the popular “Georgia Jumper” TED. Both the Diffusion of Innovation and the Traditional Ecological Knowledge literatures stress the importance of meaningful engagement of user communities in the development of new management approaches, and make specific recommendations for improving uptake of new methods. Consistent with literature expectations, fisher and industry participation in the development, testing, and implementation of TEDs has been key to the general acceptance of TEDs in Georgia. This paper illustrates the importance of fisher participation in conservation efforts such as these.

For half a century, red spruce ( Picea rubens Sarg.), a commercially and ecologically important boreal tree species, has experienced growth decline and high mortality in eastern North America. A tree growth systems model, ARIM (annual radial increment model), was developed to evaluate responsible factors for red spruce growth in the Great Smoky Mountains National Park. The dominant cause at higher elevations (1800–2000 m) was found to be air pollution involving high-frequency acidic rain and cloud immersion. The identified causes at lower elevations (1450–1700 m) were insufficient solar absorption due to photoinhibition, drought stress resulting from reduced precipitation and high evapotranspiration due to warmer temperatures, and minor effects of air pollution. The ARIM exemplifies a complex systems concept and methodology for evaluating multivariable factors in tree growth systems. ARIM provides a general model structure that incorporates complex direct and indirect interactions for tree system studies and quantitatively integrates knowledge and data from different disciplines by developing a new set of indices, the relative basis index values. The ARIM results implicate comprehensive habitat-dependent directions for long-term conservation policies and management of red spruce with environmental changes, climate change, and air pollution in the Great Smoky Mountains National Park.

ABSTRACT Some chelonians, such as the gopher tortoise ( Gopherus polyphemus ), spend much of their time underground in burrows. Often, they will retreat into these burrows when approached. This predator avoidance behavior may potentially influence the spatial use patterns that researchers directly observe via manual telemetry. In an effort to record the movements of gopher tortoises using affordable methods that reduce behavioral effects, we devised a novel application for Global Positioning System (GPS) loggers, specifically that of a low‐cost recreational unit that could be modified for extended deployment (~6 months) under gopher tortoise‐conditions. We conducted a stationary testing study of these GPS loggers whereby they were deployed at specific depths (0.5 m, 1.0 m, and 2.0 m) inside inactive burrows and on the surface at our study site in southeastern Georgia, USA, during summer 2017. This stationary trial allowed us to characterize the effect of burrow depth on GPS fix success rate (FSR), mean location error (µLE), and root mean square of the location error (LE RMS ). We found that µLE and LE RMS increased with increasing depth underground; µLE ranged from 17.34 m on the surface to 69.98 m at the 2.0‐m depth. However, following exclusion of LE outliers >3 standard deviations from each treatment mean, LE RMS decreased to 8.6 m at the surface to 40.46 m at the 2.0‐m depth. The FSR varied by burrow depth from 0.51 (2.0‐m depth) to 0.99 (surface). Additionally, we provide our attachment and deployment methods as used for studying the spatial ecology of the gopher tortoise with modified recreational GPS loggers. Overall, the modified GPS loggers performed well, obtaining 146,118 successful GPS fixes on 38 individual gopher tortoises during 84 unique deployments, each approximately 3.5–6 months in duration. © 2020 The Wildlife Society.

Coastal erosion and shoreline retreat can be offset by responsible shoreline management through nature-based solutions such as living shorelines. This study describes five roles played by environmental nonprofit organizations in shoreline management and coastal resilience in Virginia by illustrating how these nonprofits support and encourage living shorelines. The five key roles played by environmental nonprofits are: (1) public education about living shorelines, (2) advocacy for living shorelines, (3) technical assistance to design and install living shoreline projects, (4) training for professionals to increase capacity for living shoreline projects, and (5) access to funding. The government regulatory framework primarily addresses the permitting process, leaving it to nonprofit organizations to fulfill various roles beyond the actual permitting process. The implications of greater involvement by the nonprofit sector in shoreline management that encourages and supports living shorelines are discussed.

Aquaponic production of fresh produce is a sustainable agricultural method becoming widely adopted, though few studies have investigated potential food safety hazards within commercial systems. A longitudinal study was conducted to isolate and quantify several foodborne pathogens from a commercial, aquaponic farm, and to elucidate their distribution throughout. The survey was conducted over two years on a controlled-environment farm containing Nile tilapia (Oreochromis niloticus) and lettuce (Lactuca sativa). Samples (N=1,047) were collected bimonthly from three identical, independent systems, and included lettuce leaves, roots, fingerlings (7-126 d old), feces from mature fish (>126 d old), water, and sponge swabs collected from the tank interior surface. Most probable number of generic Escherichia coli were determined using IDEXX Colilert Quanti-Tray. Enumeration and enrichment were used to detect Shiga toxin-producing E. coli (STEC), Salmonella enterica, Listeria monocytogenes, Aeromonas spp., Aeromonas hydrophilia, and Pseudomonas aeruginosa. Generic E. coli, STEC, L. monocytogenes, and S. enterica were not detected in collected samples. P. aeruginosa was isolated from water (7/351; 1.99%), swabs (3/351; 0.85%), feces (2/108; 1.85%), and lettuce leaves (2/99; 2.02%). A. hydrophila was isolated from all sample types (623/1047; 59.50%). Incidence of A. hydrophila in water (X2=23.234, p<0.001) and sponge samples (X2=21.352, p<0.001) increased over time.

This study evaluated two approaches to the aquaculture of L. polyphemus with the ultimate goal of harvesting LAL at an industrial scale. To monitor HSCs, a combination of physical, biochemical and cellular components were examined for HSC cohorts in an indoor recirculating aquaculture system (RAS) and an outdoor on-bottom pen culture system (PCS) over a 6-month period. The metrics included body weight, hemocyanin (Hc) concentration, amebocyte density, and LAL reactivity. In addition, a simulated biomedical bleeding event (extracting 30% of the total hemolymph volume) was performed to assess physiochemical properties of the hemolymph and amebocytes after a one-week recovery period. Overall, the HSCs fared better in the RAS compared to the PCS, with higher rebound kinetics with respect to Hc concentrations, amebocyte density, LAL reactivity, and with 100% survival in the RAS cohort. Further, hemolymph reinfusion (after amebocyte removal) was shown to improve HSC recovery time. In summary, outcomes of this research show that a RAS, coupled with adequate nutrition and care can provide HSCs with a suitable environment for sustainable hemolymph extraction and year-round LAL production.

Beyond the well‐established benefits of wildlife road crossings and associated infrastructure—improving driver safety, reducing animal mortality, reconnecting habitats—there is another important but often underappreciated benefit: supporting wildlife and ecosystems in adapting to climate change. We explore this potential by (1) synthesizing the literature surrounding climate adaptation and wildlife crossings, (2) presenting a case study on how crossings support shifting animal migrations, and (3) describing key considerations for incorporating climate information into crossing prioritizations. Among other climate‐adaptive benefits, research suggests crossings can support species range shifts and protect access to resources even as drought and human development compromise that access. Our case study outlines an approach for prioritizing crossing locations most likely to support animal migration both today and into the future. By accounting for such dynamics, wildlife crossings can be a cost‐effective tool that protects wildlife as well as motorists and enhances the resilience of infrastructure and ecosystems in a changing world.

Professional and scientific societies are increasingly engaging in efforts to create a science community that manifests justice, equity, diversity, and inclusion (JEDI). However, progress assessment is challenging, and opportunities for community feedback are limited. During the 2022 Ocean Sciences Meeting, the Oceanography Society (TOS) JEDI committee led an interactive Town Hall to collect feedback from conference participants and TOS membership on three themes: challenges, initiatives, and opportunities related to advancing JEDI in ocean sciences. This Town Hall was preceded by a survey that was administered to the TOS membership. Survey respondents and Town Hall participants provided valuable observations and synthesis on the past, present, and future of JEDI work in ocean sciences. Discussion included both positive efforts and outcomes of JEDI work as well as harmful and ineffective practices. This paper synthesizes feedback received and highlights ways in which the ocean sciences community and professional and scientific societies can advance similar work. Gatekeeping, a system of implicit or explicit cultural and institutional constraints to and requirements for entry into a field, was identified as the most significant challenge to diversifying the ocean sciences. The majority of survey respondents agreed that efforts to broaden participation have been successful, and identified specific initiatives that have been effective, including the development and support of mentorship and training programs and partnerships with minority-serving institutions. Some challenges to advancing JEDI initiatives include targeted recruitment from the most “elite” institutions and “parachute science.” Respondents agreed that professional and scientific societies have an important role to play in advancing JEDI in ocean sciences. Participants discussed strategies to broaden participation, including efforts that can be employed by professional and scientific societies such as regular data collection on demographics, improved information sharing, and stricter codes of conduct at professional meetings. We conclude by summarizing some new TOS-led initiatives that are designed to promote JEDI in ocean sciences and beyond.

Fisheries and aquaculture provide food and economic security, especially in the developing world, but both face challenges from infectious disease. Here, we consider management of disease issues from a structured decision‐making perspective to examine how infectious disease can threaten seafood production and influence management decisions. For both wild fisheries and aquaculture, disease‐management objectives generally aim to mitigate the severity and economic burden of outbreaks. General management strategies include manipulating host densities, reducing system connectivity, conserving or improving habitat, and implementing direct treatments or some other biological interventions. To inform decisions, mathematical models can be used to explore disease dynamics and to forecast the potential effectiveness of alternative management actions. Developing and implementing disease‐management strategies also involve considering uncertainties and balancing competing stakeholder interests and risk tolerances. We conclude by outlining several steps for applying structured decision making that are broadly useful to decision makers facing issues related to disease.

Abstract The Federal Emergency Management Agency (FEMA) offers a portfolio of flood risk mitigation options for high-risk homeowners, hoping to reduce flood damages. Buyout (home acquisition) and home retrofit (e.g., home elevation) are candidates available to homeowners. FEMA has recently amended and increased its buyout efforts. This study examines homeowners’ stated preference for buyout and home elevation contracts using survey data. Results indicate multiple factors influence the decision to participate in home acquisition and elevation programs. Importantly, we find that preferences vary with the timing (whether the contract is offered before or after a damage event) of the contract offered.

With the inexorable march of climate change, increased flooding is inevitable. Understanding the feedback between federal flood mitigation policies and the ways in which local governments build flood resilience is a significant gap in the literature. In particular, the effect that federal flood mitigation grants have on the intensity of local flood mitigation is nonexistent. This work measures flood risk mitigation by using the level of participation in FEMA's Community Rating System (CRS). Communities that participate in the CRS and undertake mitigation are awarded points; more points imply a higher level of participation. Since its inception in 1990, CRS communities have received considerably more federal pre-disaster flood mitigation grants compared to non-CRS communities. This study assesses the effect of federal pre-disaster flood mitigation grants on the level of participation in the CRS program. We use data on Hazard Mitigation Assistance programs and CRS participation data between 2010 and 2015. We link these data to flood risk and socioeconomic information. Our results indicate (i) federal pre-disaster flood mitigation grants do not appear to significantly influence the level of CRS participation, (ii) the effect of flood risk and socioeconomic factors on the level of CRS participation are mixed, and (iii) the current level of CRS participation is influenced by the previous level of CRS participation, which is not tied to federal pre-disaster flood mitigation grant. These findings add to the growing discussions on the drivers and barriers of local flood risk mitigation.

Abstract We consider the goal of flood risk managers to induce voluntary flood risk mitigation actions from homeowners in at-risk areas by first distinguishing between risk metrics that are salient to policy makers and risk managers (denoted principal-salient) and risk metrics that are salient to homeowners (denoted agent-salient). We derive a single index each for principal- and agent-salient risk, then combine these indices with data on households’ preference for parcel-level flood risk mitigation activities. We estimate choice models to understand how risk indicator type affects homeowner preferences and policy recommendations. Models with agent-salient risk metrics outperform those utilizing principal-salient risk metrics. More importantly, willingness to accept estimates show the two risk measures yield significantly different policy outcomes, with greater agent-salient risk being associated with greater willingness to adopt risk mitigation but no similar relationship existing between principal-salient risk and willingness to adopt risk mitigation. We note that there are important benefits from using both types of metrics when targeting risk mitigation grants.

Abstract Benthic grazers and suspension feeders, such as oysters and mussels, may play a disproportionate role in controlling algal biomass and plankton community composition in estuarine systems. Nonetheless, their effects on plankton communities remain poorly understood across environmental contexts, in part from a paucity of in situ measurements. Here, we conducted in situ manipulative field experiments to evaluate the effects of the Atlantic ribbed mussel, Geukensia demissa , on bulk chlorophyll a (µg L − 1 ); absolute cell abundance (individuals mL − 1 ) of plankton groups &gt; 10 μm in diameter (i.e., pennate and centric diatoms, dinoflagellates, and heterotrophic nano- and microzooplankton); and relative cell abundance (%) of plankton trophic levels (i.e., auto-, mixo-, and heterotrophic) across three salt marsh sites in the southeastern U.S. (Georgia and Florida). Mussel grazing reduced both chlorophyll a concentrations and total absolute cell abundances by 120–150% compared to cordgrass only plots and the ambient water column. Mussel effects on plankton groups were consistently strong and negative, ranging from − 1.12 to − 2.51. At two of the three sites, mussels reduced pennate and centric diatoms to a greater extent (&gt; 155%) than dinoflagellates (~ 100%). This selective grazing likely shifted plankton community composition toward a more mixotrophic structure, whereby the relative contribution of autotrophic diatoms declined from roughly 80% and 65% in ambient waters to 70% and 45% in mussel plots, respectively, while the relative abundance of dinoflagellates increased. Given the essential role of the plankton community in mediating the ecological and geochemical functioning of estuaries, our results highlight that, within natural salt marshes, mussels play a significant role each tidal cycle in modifying such functions through their prolific and selective grazing on this community.

Coastal Glynn County, Georgia, is home to four hazardous sites on the United States EPA's National Priorities List. Toxicants of concern include mercury, the pesticide toxaphene, and Aroclor 1268, a mixture of highly chlorinated polychlorinated biphenyls (PCBs); these toxicants are known to persist in the local environment and/or regional aquatic life, including local seafood. At the invitation of, and in partnership with, local community leaders and environmental groups, we conducted a human exposure study in Glynn County. The average age of the study participants was 61 years, 66 % were female, and 46 % were Black. Mercury levels in study participants were comparable to the general US population. Levels of less chlorinated PCBs (PCB 118, 138, 153 and 180) were lower in participants compared to the general population, but the highly chlorinated PCBs associated with Aroclor 1268 were elevated; 19.3 %, 25.0 % and 39.8 % of participants were above the estimated 95th percentile reference values for PCBs 196 + 203, 199, and 206, respectively. About 20 % of participants were above the 95th percentile reference level for both toxaphene Parlars tested (Parlars 26 and 50). We also report on several other toxicants including other metals (lead and cadmium), p,p’-DDE, and poly- and per-fluorinated alkyl substances (PFAS). This study provides evidence that toxicants associated with local hazardous sites have contributed to exposures in Glynn County residents, and that some residents have exposures far exceeding what is common in the general population. • Participants had high levels of PCBs linked to Aroclor 1268, but not other PCBs. • Blood levels of both toxaphene Parlars were elevated in many participants. • Some individuals had exposures many times greater than population 95th percentiles. • Several focal toxicants were higher in Black participants. • Fishers and people with occupational histories of exposure showed high levels.