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Turbulence and sound are important cues for oyster reef larval recruitment. Numerous studies have found a relationship between turbulence intensity and swimming behaviors of marine larvae, while others have documented the importance of sounds in enhancing larval recruitment to oyster reefs. However, the relationship between turbulence and the reef soundscape is not well understood. In this study we made side-by-side acoustic Doppler velocimeter turbulence measurements and hydrophone soundscape recordings over 2 intertidal oyster reefs (1 natural and 1 restored) and 1 adjacent bare mudflat as a reference. Sound pressure levels (SPL) were similar across all three sites, although SPL >  2000 Hz was highest at the restored reef, likely due to its larger area that contained a greater number of sound-producing organisms. Flow noise (FN), defined as the mean of pressure fluctuations recorded by the hydrophone atf<  100 Hz, was significantly related to mean flow speed, turbulent kinetic energy, and turbulence dissipation rate (ε), agreeing with theoretical calculations for turbulence. Our results also show a similar relationship between ε andFNto what has been previously reported for ε vs. downward larval swimming velocity (w_b), with bothFNandw_bdemonstrating rapid growth at ε >  0.1 cm²s⁻³. These results suggest that reef turbulence and sounds may attract oyster larvae in complementary and synergistic ways. 

Abstract Megaripples are current‐generated seafloor bedforms of well‐sorted sand or gravel and wavelengths over 1 m. In this aquatic eddy covariance study, we measured large rates of benthic primary production and respiration for a shallow‐water sandy megaripple field exposed to strong tidally driven currents and intense sunlight. Current and light were the main short‐term drivers of a highly dynamic oxygen exchange. Daytime oxygen release as high as 300 mmol m⁻² d⁻¹and nighttime oxygen uptake up to −100 mmol m⁻² d⁻¹were likely sustained by current‐driven transport of oxygen, nutrients, and organic matter (fuel) into and out of the sand and superimposed by rapid internal cycling. Seasonal differences in temperature (45%) and light (69%) between April and September were the main long‐term drivers of substantially greater rates of gross primary production and respiration in September. The megaripples functioned as an intense metabolic hotspot with carbon cycling rates larger than those of most near‐shore sediments. 

Abstract Students lose interest in science as they progress from elementary to high school. There is a need for authentic, place‐based science learning experiences that can increase students' interest in science. Scientists have unique skillsets that can complement the work of educators to create exciting experiences that are grounded in pedagogy and science practices. As scientists and educators, we co‐developed a lesson plan for high school students on the Eastern Shore of Virginia, a historically underserved coastal area, that demonstrated realistic scientific practices in students' local estuaries. After implementation of the lesson plan, we observed that students had a deeper understanding of ecosystem processes compared to their peers who had not been involved, were enthusiastic about sharing their experiences, and had a more well‐rounded ability to think like a scientist than before the lesson plan. We share our experiences and five best practices that can serve as a framework for scientists and educators who are motivated to do similar work. Through collaboration, scientists and educators have the potential to bolster student science identities and increase student participation in future scientific endeavors. 

As part of a long-term study on the effects of nitrogen (N) loading in a shallow temperate lagoon, we measured rates of N₂fixation associated with seagrass (Zostera marina) epiphytes during the summer from 2005 to 2019, at two sites along a gradient from where high N groundwater enters the system (denoted SH) to a more well-flushed outer harbor (OH). The data presented here are the first such long-term N₂fixation estimates for any seagrass system and one of the very few reported for the phyllosphere in a temperate system. Mean daily N₂fixation was estimated from light and dark measurements using the acetylene reduction assay intercalibrated using both incorporation of¹⁵N₂into biomass and a novel application of the N₂:Ar method. Surprisingly, despite a large inorganic N input from a N-contaminated groundwater plume, epiphytic N₂fixation rates were moderately to very high for a seagrass system (OH site 14-year mean of 0.94 mmol N m⁻² d⁻¹), with the highest rates (2.6 mmol N m⁻² d⁻¹) measured at the more N-loaded eutrophic site (SH) where dissolved inorganic N was higher and soluble reactive phosphorus was lower than in the better-flushed OH. Over 95% of the total N₂fixation measured was in the light, suggesting the importance of cyanobacteria in the epiphyte assemblages. We observed large inter-annual variation both within and across the two study sites (range from 0.1 to 2.6 mmol N fixed m⁻²d⁻¹), which we suggest is in part related to climatic variation. We estimate that input from phyllosphere N₂fixation over the study period contributes on average an additional 20% to the total daily N load per area within the seagrass meadow. 

ABSTRACT Meiofauna, organisms smaller than 1 mm, are the most abundant and diverse invertebrates inhabiting the world's ocean floor but their contribution to benthic oxygen demand is still poorly constrained. This knowledge is crucial for understanding seabed respiration, global marine carbon, and oxygen cycles, which are relevant to all nutrient cycling and energy flows in the ecosystem. It is common to predict meiofauna respiration based on their biomass or volume, which are difficult to quantify, and thus meiofauna are rarely included in biogeochemistry studies. In addition, it is still unknown how well the generalized allometric relations describe all meiofauna respiration. Therefore, we used a novel approach specially developed for single meiofauna respiration measurements to derive the respiration rates of 10 meiofauna groups in two marine and one brackish coastal muddy environments under oxic and hypoxic conditions, representing natural sediment conditions. Our estimates suggest that large ostracods and juveniles of macrofauna (e.g., bivalves, trumpet worms, and priapulids) had the highest individual respiration rates. Meiofauna community as a whole contributed 3–33% to sediment oxygen uptake. However, the most important contributors to the overall sediment oxygen uptake were nematodes and foraminifera which had lower respiration rates but were highly abundant. Therefore, out of more than 22 meiofauna phyla, we recommend that nematode and foraminifera respiration, which contributes 3–30% (total 3–33%) to sediment oxygen uptake, should be taken into consideration in any estimations of benthic oxygen and carbon cycles. 

Coastal landscapes are naturally shifting mosaics of distinct ecosystems that are rapidly migratingwith sealevel rise. Previous work illustrates that transitions among individual ecosystems have disproportionate impacts on the global carbon cycle, but this cannot address nonlinear interactions between multiple ecosystems that potentially cascade across the coastal landscape. Here, we synthesize carbon stocks, accumulation rates, and regional land cover data over 36 years (1984 and 2020) for a variety of ecosystems across a large portion of the rapidly transgressing mid-Atlantic coast. The coastal landscape of the Virginia Eastern Shore consists of temperate forest, salt marsh, seagrass beds, barrier islands, and coastal lagoons. We found that rapid losses and gains within individual ecosystems largely offset each other, which resulted in relatively stable areas for the different ecosystems, and a 4% (196.9 Gg C) reduction in regional carbon storage. However, new metrics of carbon replacement times indicated that it would take only 7 years of carbon accumulation in surviving ecosystems to compensate this loss. Our findings reveal unique compensatory mechanisms at the scale of entire landscapes that quickly absorb losses and facilitate increased regional carbon storage in the face of historical and contemporary sea-level rise. However, the strength of these compensatory mechanisms may diminish as climate change exacerbates the magnitude of carbon losses. 

Phytoplankton and sea ice algae are traditionally considered to be the main primary producers in the Arctic Ocean. In this Perspective, we explore the importance of benthic primary producers (BPPs) encompassing microalgae, macroalgae, and seagrasses, which represent a poorly quantified source of Arctic marine primary production. Despite scarce observations, models predict that BPPs are widespread, colonizing ~3 million km²of the extensive Arctic coastal and shelf seas. Using a synthesis of published data and a novel model, we estimate that BPPs currently contribute ~77 Tg C y⁻¹of primary production to the Arctic, equivalent to ~20 to 35% of annual phytoplankton production. Macroalgae contribute ~43 Tg C y⁻¹, seagrasses contribute ~23 Tg C y⁻¹, and microalgae-dominated shelf habitats contribute ~11 to 16 Tg C y⁻¹. Since 2003, the Arctic seafloor area exposed to sunlight has increased by ~47,000 km²y⁻¹, expanding the realm of BPPs in a warming Arctic. Increased macrophyte abundance and productivity is expected along Arctic coastlines with continued ocean warming and sea ice loss. However, microalgal benthic primary production has increased in only a few shelf regions despite substantial sea ice loss over the past 20 y, as higher solar irradiance in the ice-free ocean is counterbalanced by reduced water transparency. This suggests complex impacts of climate change on Arctic light availability and marine primary production. Despite significant knowledge gaps on Arctic BPPs, their widespread presence and obvious contribution to coastal and shelf ecosystem production call for further investigation and for their inclusion in Arctic ecosystem models and carbon budgets.