Louisiana Universities Marine Consortium

This protocol provides guidance on the appropriate collection of bee specimens or tissue samples for molecular analysis, with an emphasis on generating genetic and genomic data while ensuring tissue integrity. Specifically, the protocol focuses on tissue collection and storage methods, including relevant specimen metadata recording and reporting, but does not cover any downstream handling or analyses, which vary depending on the aims of a given project or study. This protocol is specifically designed for freshly collected, individual bee specimens intended for genetic, genomic, or other molecular analyses. While molecular approaches to bee monitoring are not the primary focus, we emphasize their promising role for future applications. This protocol is part of a series developed in association with the U.S. National Native Bee Monitoring Network to standardize bee monitoring practices.

Standardizing data collection methods is essential for advancing research, monitoring, and conservation efforts on bees. Greater consistency in data practices will enable the production of higher-quality, interoperable datasets, fostering a deeper understanding of bee populations and trends over time. This special issue series of Journal of Melittology presents six articles outlining standardized protocols and data standards to support wild bee data collection efforts, together with this article, which makes a general argument for greater standardization. These protocols are applicable to a wide range of research efforts to maximize the quality and use of wild bee occurrence data and can also be integrated into formal monitoring programs. Here, we first outline the need for, and an overview of, a series of standardized protocols and data standards developed in association with the U.S. National Native Bee Monitoring Research Coordination Network. We provide guidance on how to decide among the protocols to achieve different objectives. We then summarize key features of the protocols, including (i) how they are designed to focus on collecting only essential information, while also providing additional recommendations; (ii) that they are intended to be embedded within whatever broader sampling schemes have been designed to meet individual project or program objectives; and (iii) their emphasis on data standards. Lastly, we argue for the collection of additional ecological information that can be used to contextualize wild bee occurrence data. This information supports hypothesis testing to better understand the causal drivers underlying the status and trends of wild bees.

Abstract. Wetland and upland ecosystems play significant but opposing roles in the global methane (CH4) budget, acting as natural sources and sinks, respectively. Two of the most common approaches for measuring CH4 fluxes (FCH4) are chambers, which capture temporally intermittent, fine-scale spatial heterogeneity (ca. 1 m2), and eddy covariance (EC) towers, which cover a larger area (ca. 100–10000 m2) at a longer term. Although chamber and EC observations have been combined in various syntheses and databases to estimate CH4 budgets, a unified cross-site evaluation of FCH4 estimates at plot and ecosystem scales is lacking. As a first step toward a systematic spatiotemporal scaling of EC tower and chamber footprints, we quantified the differences between site-level aggregate FCH4 (EC vs chamber; ΔFCH4) from ten wetland and upland sites at half-hourly, hourly, daily, weekly, monthly, and annual timescales. We found that ecosystem-scale median FCH4 was consistently higher than plot-scale FCH4 at all temporal scales, with the smallest difference at daily timescale (multi-site median ΔFCH4: 1.36 nmol m-2 s-1; ~ 104 % higher ecosystem-scale than plot-scale FCH4) and largest at annual scales (2.58 nmol m-2 s-1; ~ 87 % higher ecosystem-scale than plot-scale FCH4). In general, the agreement between ecosystem- and plot-scale FCH4 decreased with finer temporal resolution (from Spearman ⍴ = 0.95 at annual scale to ⍴ = 0.65 at half-hourly scale), while ΔFCH4 variation was greatest at daily-to-annual scales. Key environmental predictors of ΔFCH4 included plot-scale spatial heterogeneity, dominant vegetation type, vapor pressure deficit, atmospheric pressure, and friction velocity at the daily and monthly scales. Wind direction was a significant predictor only at the monthly scale, suggesting EC footprint effects. These findings suggest accounting for variation in EC footprint extent, chamber measurement placement and artifacts is key to reconciling multi-scale FCH4 observations in diverse ecosystems and refining CH4 budgets.

The development of distributaries in large river deltas plays an important role in the geology, hydrology, and ecology of the coastal ocean, as large rivers are a dominant mechanism by which particulate, suspended, and dissolved material is delivered from the continents to the global ocean. And yet, there is relatively little, near-real time observational data on the development of distributaries in large river deltas -- in part because the development of modern observation coincides with an era when rivers have been controlled by large engineering projects (i.e., the 20th and 21st centuries). This article reports on Neptune Pass, the largest new distributary to form in the Mississippi River in nearly a century. It developed between 2019 and 2021 when a small canal rapidly expanded by at least an order of magnitude. The system now carries about 15-17% of the flow of the Mississippi River, > 3,000 m3 s-1 when the Mississippi River is at moderately high flows. This is comparable to the 10th largest river in North America and the 100th largest river on Earth. Neptune Pass is building a delta, and this study sought to examine whether this delta is comprised largely of material eroded from the Neptune Pass (redistributed sediment hypothesis), or includes material recently derived from the Mississippi River (new sediment hypothesis). These hypotheses were tested using a combination of marine-geophysical surveys, remote sensing techniques, and sediment core collections. Results indicate that the delta in Quarantine Bay was 56-79% larger than the material excavated from Neptune Pass, corroborating the new sediment hypothesis, and indicating that it is a net land building system. These findings provide key insights that are critical to the restoration and safe management of the Mississippi River and its delta, the largest system of its kind in North America.

Many species of fish produce sounds that can be used to monitor them non-intrusively and could complement traditional monitoring techniques. However, the manual annotation of fish sounds in acoustic recordings remains time-intensive, limiting the use of passive acoustics as a viable monitoring tool. This study compares two automated approaches for detecting fish sounds: Random Forest (RF) and Convolutional Neural Networks (CNN). Both algorithms were trained on 21,950 manually labeled fish and non-fish sounds recorded between 2014 and 2019 in the Strait of Georgia, British Columbia, Canada. Performance calculated on data from the Strait of Georgia, Barkley Sound, and the Port of Miami showed that the CNN performed up to 1.9 times better than the RF (F-score: 0.82 versus 0.43) and was in some cases able to find more faint fish sounds than the analyst. Noise analysis in the 20–1000 Hz frequency band shows that the CNN is still reliable in noise levels greater than 130 dB re 1 μPa in the Port of Miami but becomes less reliable in Barkley Sound past 100 dB re 1 μPa due to mooring noise. We show that the proposed approach can make passive acoustics viable for monitoring fish in a variety of environments.

Coastal wetlands are hotspots of carbon sequestration, and their conservation and restoration can help to mitigate climate change. However, there remains uncertainty on when and where coastal wetland restoration can most effectively act as natural climate solutions (NCS). Here, we synthesize current understanding to illustrate the requirements for coastal wetland restoration to benefit climate, and discuss potential paths forward that address key uncertainties impeding implementation. To be effective as NCS, coastal wetland restoration projects will accrue climate cooling benefits that would not occur without management action (additionality), will be implementable (feasibility) and will persist over management-relevant timeframes (permanence). Several issues add uncertainty to understanding if these minimum requirements are met. First, coastal wetlands serve as both a landscape source and sink of carbon for other habitats, increasing uncertainty in additionality. Second, coastal wetlands can potentially migrate outside of project footprints as they respond to sea-level rise, increasing uncertainty in permanence. To address these first two issues, a system-wide approach may be necessary, rather than basing cooling benefits only on changes that occur within project boundaries. Third, the need for NCS to function over management-relevant decadal timescales means methane responses may be necessary to include in coastal wetland restoration planning and monitoring. Finally, there is uncertainty on how much data are required to justify restoration action. We summarize the minimum data required to make a binary decision on whether there is a net cooling benefit from a management action, noting that these data are more readily available than the data required to quantify the magnitude of cooling benefits for carbon crediting purposes. By reducing uncertainty, coastal wetland restoration can be implemented at the scale required to significantly contribute to addressing the current climate crisis.

Coastal wetlands are hotspots of carbon sequestration, and their conservation and restoration can help to mitigate climate change. However, there remains uncertainty on when and where coastal wetland restoration can most effectively act as natural climate solutions (NCS). Here, we synthesize current understanding to illustrate the requirements for coastal wetland restoration to benefit climate, and discuss potential paths forward that address key uncertainties impeding implementation. To be effective as NCS, coastal wetland restoration projects will accrue climate cooling benefits that would not occur without management action (additionality), will be implementable (feasibility) and will persist over management-relevant timeframes (permanence). Several issues add uncertainty to understanding if these minimum requirements are met. First, coastal wetlands serve as both a landscape source and sink of carbon for other habitats, increasing uncertainty in additionality. Second, coastal wetlands can potentially migrate outside of project footprints as they respond to sea-level rise, increasing uncertainty in permanence. To address these first two issues, a system-wide approach may be necessary, rather than basing cooling benefits only on changes that occur within project boundaries. Third, the need for NCS to function over management-relevant decadal timescales means methane responses may be necessary to include in coastal wetland restoration planning and monitoring. Finally, there is uncertainty on how much data are required to justify restoration action. We summarize the minimum data required to make a binary decision on whether there is a net cooling benefit from a management action, noting that these data are more readily available than the data required to quantify the magnitude of cooling benefits for carbon crediting purposes. By reducing uncertainty, coastal wetland restoration can be implemented at the scale required to significantly contribute to addressing the current climate crisis.