Amanda Kirkland

In addition to steep carbon emission reductions, all modeled pathways to reach global climate goals require carbon removal. Marine carbon dioxide removal has the potential to play a large role in drawing down legacy anthropogenic emissions due to the scalability and durability of proposed methods. While this field is rapidly expanding, a number of issues remain, including efforts to grow the industry, align projects with equity and justice goals, and ensure development of trusted, unique, durable carbon credits. We, a group of early career ocean professionals (ECOPs), provide an overview of the scale of the field, the aforementioned issues, and then make recommendations to ensure global equity and expand early career capacity in the marine carbon dioxide removal sector. We argue that substantial investment is needed to reduce costs of marine carbon dioxide removal and spur innovation in monitoring, reporting, and verification, but also in the training and development of early career researchers. Careful co‐design of marine removal projects by experienced and emerging collaborators, including local communities, can help mitigate perpetuating existing global inequalities. Given the anticipated growth of the marine carbon dioxide removal workforce, ECOPs can contribute their existing interdisciplinary expertise, if they are supported within traditional structures. Those entering the field can leverage skill sets that intersect engineering, policy, community engagement, and business. We maintain that ECOPs will be key leaders in the field, if appropriately engaged, compensated, and empowered.

Global ocean change can negatively impact bivalves, that serve to increase microhabitat and clarify waters in coastal ecosystems. Although effects of global stressors on commercial bivalves have been studied, predicting effects on non-commercial species is challenging due to species-specific responses and potential for synergistic or antagonistic effects when stressors are combined. We assessed the impact of global ocean change on the leafy jewel box clam, Chama macerophylla, a widely distributed epifaunal species. We focused on clams in the northern Gulf of Mexico, where amplified warming and acidification are anticipated. We hypothesized adult clams would experience heightened physiological stress when exposed to warming and acidification, with synergistic effects to combined stressors. Moderate and extreme stressor(s) used in experiments were seldom to never recorded in clam habitat. Yet, 98% of clams survived a 30-day laboratory exposure to single and combined stressor(s). Shells were bimineralic and no alterations in mineral composition were observed. Initially, clams at ambient carbonate chemistry showed increased respiration with higher temperatures, that were subsequently lower by day 30. Notably, clams, when at a constant ambient temperature, exhibited the highest calcification in the most acidic waters, suggesting a compensatory mechanism. When both stressors were present, respiration did not increase as expected with warmer temperatures, and extreme conditions led to variable calcification. Physiological responses from multi-stressor experiments were not statistically relatable to the stress condition, making it challenging to discern impacts of multi-stressors. This study highlights the importance of understanding adaptive mechanisms and long-term stress on bivalves crucial to benthic-pelagic coupling.

Seagrasses, corals, marsh plants, kelps, and mangroves support valuable coastal ecosystems but are threatened by environmental stressors. The need to manage these foundation taxa has spurred more than a decade of study on the relationship between genetic diversity and function or stability. We synthesized this literature base (129 relevant publications) and found more reported instances of neutral to positive relationships between genetic diversity and function than negative. However, much of the scientific understanding is based on the response of three genera and from unreplicated observational studies that correlate genetic diversity to measured response variables. When a disturbance was present, the studies often lacked controls or baseline data. Only 5.5% of the studies robustly tested for stability. These shortcomings preclude a rigorous evaluation of whether more genetically diverse foundation populations increase stability and hinder the use of genetics-based conservation strategies. Future studies should be focused on diverse species and ecosystem-level impacts using manipulative designs.