Interest and engagement in aquaculture has been increasing in recent years to meet aquatic resource demands, and much attention has been directed to growing seaweed in the United States. However, research and regulatory environments have not kept pace with its growth, leading to challenges to expanding the industry, and in many cases, these developments may be ahead of available peer-reviewed literature, resulting in a dearth of information from industry participants about their needs and perspectives. The results of the first survey of industry members and those adjacent to the US domestic seaweed aquaculture industry are presented. Presenting contributions of participants throughout the supply chain from seaweed seed string producers through to processors and culinary professionals, and including regulators and researchers. A total of 268 respondents responded to the needs assessment survey, with engagement from fourteen states, primarily representing the U.S. northeast and west coasts. Results describe a wide differential in levels of industry engagement and development across states with Maine providing an example of a well-developed industry, and others just beginning to develop seaweed growing permits and infrastructure. Respondents were asked to identify challenges which were then categorized as: (1) production systems (32%); (2) market opportunities, including both supply and demand (26%); (3) regulations (26%); and (4) post-harvest opportunities and infrastructure (i.e., processing facilities) (16%). Considering these challenges collectively, a holistic approach to scaling up the industry is needed to address challenges throughout the supply chain and across states. The paper concludes with recommendations for policy makers, regulators, extension professionals and researchers to assist this nascent industry in scaling up domestically by working to facilitate information transfer across states and roles within the industry to increase capacity at various levels of the supply chain, address remaining scientific questions, and move toward a regulatory framework for an inter-state (or domestic) industry.

Great Bay Estuary (GBE), within the rapidly warming Gulf of Maine, has experienced significant ecological shifts this century due to naturalization of invasive species. The range expansion of the American blue crab (Callinectes sapidus) currently underway from the mid-Atlantic northward brings the possibility of similar ecological shifts. This study accounts recent trapping and diet analysis of C. sapidus in GBE. Diet is an important component of understanding how the blue crab range expansion may affect GBE ecosystem functions. Across all sites and trap types, 27 blue crabs were captured. Metagenomic analysis of shotgun sequencing techniques were used on the gut contents of blue crabs captured. Most specimens had > 50

ABSTRACTGreat Bay Estuary (GBE) is a complex estuarine system at the convergence of seven rivers, ocean and land. The GBE ecosystem supports typical estuarine species but, like many estuaries, has been a target of both invasive and range‐expanding species. The goal of this study was to compare abundance, sex and size distribution of green crabs between oyster farm sites and non‐farmed sites within GBE in 2021 and 2022. Overall catch was higher in 2021 compared to 2022. The highest population of green crabs was estimated to be in the farm area around Cedar Point, and natural/restoration area near Moody Point had the smallest European green crab population. In both years, the majority of green crabs captured (98%) were adult males, and few were juveniles captured. At the last sampling date of 2021 and 2022, most crabs were large (68 ± 0.5 mm and 63 ± 2 mm carapace width, respectively). Shellfish growers, restoration and management teams could use these data in mitigation strategies to sustain industries and enhance GBE health. This information is important for oyster restoration initiatives and oyster growers as they may want to: consider putting traps around their restoration reefs and farms to help reduce green crab infestation/predation in their growing areas; make decisions regarding best management practices and optimal growing locations when applying for permits; and work with management teams with gear improvement, such as floating gear, to reduce green crab intrusion into cages. High‐priority locations for trapping should be areas such as oyster farms, oyster reefs and restoration sites.

Engaging relevant stakeholders, specifically those with opposing views, is a challenge many Extension professionals face. Employing practical methods to engage opposing sectors is critical in implementing projects to ensure long-term success. Advocacy-driven messaging has fueled interest in seaweed farming, however, existing practical challenges have led to frustration from relevant sectors. The National Seaweed Hub serves as a central clearinghouse for available science-based, non-advocate, and practical resources related to the emerging domestic seaweed aquaculture industry. Through facilitated sector-driven work groups and other engagement activities, seaweed sectors collaborated and strategized to generate implementable projects, ideas and resources targeting barriers to industry expansion.

On 2 September and 7 October 2022, we captured post-copulatory pairs of Callinectes sapidus (Blue Crab) in Green Crab traps in Great Bay Estuary, NH. On the first occasion, the 2 crabs included a mature post-ecdysis (12-24 hour) female and a mature male, and the female's shed exoskeleton also remained in the trap. Both seminal receptacles had pink sperm plugs and were turgid with spermatophores, indicative of recent successful insemination. Details of the second capture mirrored the first with the exception that the exuvia was not in the trap. This is the first scientific reporting of Blue Crabs mating in Great Bay Estuary, NH, documenting an ongoing range expansion of a species with the potential to have major ecological and economic impacts.

We extracted and analyzed microplastics (MP) in archived sediment cores from Great Bay Estuary (GBE) in the Gulf of Maine region of North America. Results indicated that MP are distributed in GBE sediments, 0-30 cm, at an average occurrence of 116 ± 21 particles g-1 and that morphology varies by site and depth. Analysis by sediment depth and age class indicated that MP accumulation increased over several decades but recently (5-10 years) has likely begun to decrease. Hydrodynamic and particle transport modeling indicated that bed characteristics are a more controlling factor in MP distribution than typical MP properties and that the highest accumulation likely occurs in regions with weaker hydrodynamic flows and lower bed shear stress, e.g., eelgrass meadows and along fringes of the Bay. These results provide a baseline and predictive understanding of the occurrence, morphology, and sedimentation of MP in the estuary.