Data used to generate statistical analysis in the manuscript "Carbon limitation in response to nutrient loading in an eelgrass mesocosm: influence of water residence time on eutrophication expression" by Kaldy, Brown and Pacella. This dataset is associated with the following publication: Kaldy, J., C. Brown, and S. Pacella. Carbon limitation in response to nutrient loading in an eelgrass mesocosm: influence of water residence time.. MARINE ECOLOGY PROGRESS SERIES. Inter-Research, Luhe, GERMANY, 689: 1-17, (2022).

Marine carbon dioxide removal (mCDR) approaches are under development to mitigate the effects of climate change by sequestering carbon in stable reservoirs, with potential co-benefits of local reduction of coastal acidification impacts. One such method is ocean alkalinity enhancement (OAE). A specific OAE method is the generation of aqueous alkalinity via electrochemistry to enhance the alkalinity of the receiving water by the extraction of acid from seawater, thereby avoiding issues of solid dissolution kinetics and the release of impurities into the ocean from alkaline minerals. While electrochemical acid extraction is a promising method for increasing the carbon dioxide sequestration potential of the ocean, the biological effects of increasing seawater alkalinity and pH within an OAE project site are relatively unknown. This study aims to address this knowledge gap by testing the effects of increased pH and alkalinity, delivered in the form of aqueous NaOH, on two eelgrass epifauna in the U.S. Pacific Northwest, Taylor’s sea hare (Phyllaplysia taylori) and eelgrass isopod (Idotea resecata), chosen for their ecological importance as salmon prey and for their roles in eelgrass ecosystems. Four-day experiments were conducted in closed bottles to allow measurements of the evolution of carbonate species throughout the experiment with water refreshed twice daily to maintain elevated pH, across pHNBS treatments ranging from 7.8 to 9.3. Sea hares experienced mortality in all pH treatments, ranging from 37% mortality at pHNBS 7.8 to 100% mortality at pHNBS 9.3. Isopods experienced lower mortality rates in all treatment groups, ranging from 13% at pHNBS 7.8 to 21% at pHNBS 9.3, which did not significantly increase with higher pH treatments. These experiments represent an extreme of constant exposure to elevated pH and alkalinity, which should be considered in the context of both the natural variation and the dilution of alkalinity experienced by marine communities across an OAE project site. Different invertebrate species will likely have different responses to increased pH and alkalinity, depending on their physiological vulnerabilities. Investigation of the potential vulnerabilities of local marine species will help inform the decision-making process regarding mCDR planning and permitting.

Gas fluxes (carbon dioxide, methane, nitrous oxide), sediment, environmental variables, nutrients, eelgrass and macroalgae data collected from coastal lagoons in southern Rhode Island in 2022 and 2023.

Eelgrass (Zostera marina) characteristics, sediment grain size distributions, sediment total organic carbon contents (TOC), carbon isotope ratios of sediment organic matter, and total carbon to total nitrogen ratios were measured at four lower intertidal sites in Bellingham Bay, Washington, July 2-5, 2019.

Eelgrass (Zostera marina) characteristics, sediment grain size distributions, sediment total organic carbon contents (TOC), carbon isotope ratios of sediment organic matter, and total carbon to total nitrogen ratios were measured at four lower intertidal sites in Bellingham Bay, Washington, July 2-5, 2019.

These files house the data collected during 2013 in lower Pensacola Bay. The data were used to estimate aquatic primary production and respiration. This dataset is associated with the following publication: Caffrey, J., M. Murrell , K. Amacker, J. Harper, S. Phipps, and M. Woodrey. Seasonal and interannual patterns in primary production, respiration and net ecosystem metabolism in three estuaries in the northeast Gulf of Mexico. Estuaries and Coasts. Estuarine Research Federation, Port Republic, MD, USA, 20, (2013).

These files house the data collected during 2013 in lower Pensacola Bay. The data were used to estimate aquatic primary production and respiration. This dataset is associated with the following publication: Caffrey, J., M. Murrell , K. Amacker, J. Harper, S. Phipps, and M. Woodrey. Seasonal and interannual patterns in primary production, respiration and net ecosystem metabolism in three estuaries in the northeast Gulf of Mexico. Estuaries and Coasts. Estuarine Research Federation, Port Republic, MD, USA, 20, (2013).

The MEQ monitoring program is being implemented in 35-40 estuaries in the southern Gulf of St. Lawrence (sGSL) to support the development of a MEQ measure (threshold) to promote efforts to address nutrient enrichment in estuaries. The two main indicators included in the monitoring program are dissolved oxygen and eelgrass coverage which are used to assess the trophic status of estuaries within the region. The two factors most important for impacting the trophic status of estuaries are nitrogen loading and water residence time, i.e., water circulation. If water residence time is long and/or nitrogen loading is high, nutrient impacts are likely. A peer-reviewed manuscript has demonstrated that these two factors are predictive of the dissolved oxygen regime in the upper estuary and that publication successfully used dissolved oxygen to ascribe trophic status to estuaries. In a companion paper it was also determined that nitrogen loading was negatively correlated with eelgrass coverage. These two papers form the basis of the MEQ monitoring program (see attached).

As part of the Northeast Coastal and Barrier Network's Estuarine Nutrient Enrichment Monitoring program, Network staff and cooperators continued to monitor seagrass cover and health at several park units. This file contains seagrass monitoring data collected between 2003 and 2024 field season at Assateague Island National Seashore, Cape Cod National Seashore, and Fire Island National Seashore.

As part of the Northeast Coastal and Barrier Network's Estuarine Nutrient Enrichment Monitoring program, Network staff and cooperators continued to monitor seagrass cover and health at several park units. This file contains seagrass monitoring data collected between 2003 and 2024 field season at Assateague Island National Seashore, Cape Cod National Seashore, and Fire Island National Seashore.