Exploring private land conservation non-adopters’ attendance at outreach events in the Chesapeake Bay watershed, USA

Background Outreach events such as trainings, demonstrations, and workshops are important opportunities for encouraging private land operators to adopt voluntary conservation practices. However, the ability to understand the effectiveness of such events at influencing conservation behavior is confounded by the likelihood that attendees are already interested in conservation and may already be adopters. Understanding characteristics of events that draw non-adopters can aid in designing events and messaging that are better able to reach beyond those already interested in conservation. Methods For this study, we interviewed 101 operators of private agricultural lands in Maryland, USA, and used descriptive statistics and qualitative comparative analysis to investigate differences between the kinds of outreach events that adopters and non-adopters attended. Results Our results suggested that non-adopters, as compared to adopters, attended events that provided production-relevant information and were logistically easy to attend. Further, non-adopters were more selective when reading advertisements, generally preferring simplicity. Future research and outreach can build on these findings by experimentally testing the effectiveness of messages that are simple and relevant to farmers’ production priorities.

A Season Independent U-net Model for Robust Mapping of Solar Arrays Using Sentinel-2 Imagery

We have an unprecedented ability to map the Earth’s surface as deep learning technologies are applied to an abundance of high-frequency Earth observation data. Simple, free, and effective methods are needed to enable a variety of stakeholders to use these tools to improve scientific knowledge and decision making. Here we present a trained U-Net model that can map and delineate ground mounted solar arrays using publicly available Sentinel-2 imagery, and that requires minimal data pre-processing and no feature engineering. By using label overloading and image augmentation during training, the model is robust to temporal and spatial variation in imagery. The trained model achieved a precision and recall of 91.5% each and an intersection over union of 84.3% on independent validation data from two distinct geographies. This generalizability in space and time makes the model useful for repeatedly mapping solar arrays. We use this model to delineate all ground mounted solar arrays in North Carolina and the Chesapeake Bay watershed to illustrate how these methods can be used to quickly and easily produce accurate maps of solar infrastructure.

Assessment of Reintroduction of American Eel into Buffalo Creek (Susquehanna River, Pennsylvania)

American Eel Anguilla rostrata populations along the Atlantic coast of the United States have been in decline over the past several decades. One suggested cause of the decline is construction of barriers that block access to upstream tributaries where they can spend a significant portion of their lives. Success of reintroduction efforts above barriers has rarely been evaluated. Within the Susquehanna River (Chesapeake Bay watershed), over 1 million eels were released above four major downstream barriers in the past decade. We used backpack electrofishing and tagging to monitor growth, sexual differentiation, and population density of reintroduced eels in Buffalo Creek, a tributary to the Susquehanna River (Pennsylvania). From 2012 to 2019, we caught over 2,000 individuals, tagged more than 1,800, and recaptured 229. Recaptured eels provided insight into growth, sexual differentiation, and movement. Nearly 99% of recaptures remained near stocking locations. The average growth rate was 47.8 mm/y and ranged between −5.8 and 116.0 mm/y. Females generally grew significantly faster than males, and growth rates of several females exceeded 100 mm/y, a rate typically associated with estuarine residents. The population density within stocking sites was over 2,300 eels/km, roughly four times higher than Susquehanna River tributaries below the most downstream dam, and exceeded the target stocking goal of 529 eels/km. While we caught most eels in areas sampled near stocking locations, we captured some eels in smaller upstream tributaries away from stocking locations. Our study is the first to examine how reintroduced eels grow following stocking above four major dams on the Susquehanna River. We suggest that managers considering moving eels above blockages account for release location and density to achieve desired benefits to the overall population.

Perfluoroalkyl Substances in Plasma of Smallmouth Bass from the Chesapeake Bay Watershed

Smallmouth bass Micropterus dolomieu is an economically important sportfish and within the Chesapeake Bay watershed has experienced a high prevalence of external lesions, infectious disease, mortality events, reproductive endocrine disruption and population declines. To date, no clear or consistent associations with contaminants measured in fish tissue or surface water have been found. Therefore, plasma samples from two sites in the Potomac River and two in the Susquehanna River drainage basins, differing in land-use characteristics, were utilized to determine if perfluoroalkyl substances were present. Four compounds, perfluorooctane sulphonic acid (PFOS), perfluoroundecanoic acid (PFUnA), perfluorodecanoic acid (PFDA) and perfluorododecanoic acid (PFDoA), were detected in every fish. Two additional compounds, perfluorooctane sulphonamide (PFOSA) and perfluorononanoic acid (PFNA), were less commonly detected at lower concentrations, depending on the site. Concentrations of PFOS (up to 574 ng/mL) were the highest detected and varied significantly among sites. No seasonal differences (spring versus fall) in plasma concentrations were observed. Concentrations of PFOS were not significantly different between the sexes. However, PFUnA and PFDoA concentrations were higher in males than females. Both agricultural and developed land-use appeared to be associated with exposure. Further research is needed to determine if these compounds could be affecting the health of smallmouth bass and identify sources.