Purpose: The decline in biodiversity caused by human activities is a major global challenge. An important driver of biodiversity loss, especially in the oceans, is seafood production. However, methods for quantifying biodiversity impacts in life cycle assessment (LCA) are currently heavily focused on terrestrial systems. This study aims to identify and evaluate methods addressing aquatic biodiversity loss relevant for LCAs of seafood and to provide recommendations to research and LCA practitioners. Methods: The methodology comprised four key phases. First, environmental impacts from seafood production were identified and linked to biodiversity impacts. Second, it was assessed which impacts were addressed in existing seafood LCAs. Next, available biodiversity impact assessment methods were identified through a literature review. Finally, the identified assessment methods were evaluated and matched against the identified environmental impacts from seafood production to evaluate the efficacy of current LCA practices. Results and discussion: A total of 39 environmental impacts linked to seafood production were identified. Of these impacts, 90% were categorized as causing biodiversity loss and included effects on genetic, species, and ecosystem level. Only 20% out of the impacts associated to aquatic biodiversity loss had been included in previous seafood LCAs, indicating a narrow scope in practice, as methods were available for half of the impacts. The available methods were, however, mainly focused on impact on species level and on the drivers pollution and climate change rather than the main drivers of marine biodiversity loss: exploitation and sea-use change. Conclusions: Although many of the impacts from seafood production were related to biodiversity pressures, LCAs which are widely used to describe the environmental performance of seafood, disregard most biodiversity impacts from seafood production. The most severe limitations were the lack of methods for the pressures of exploitation and sea-use change and for effects on ecosystem and genetic biodiversity. This study provides recommendations to practitioners on how to best account for biodiversity impacts from seafood depending on the studied system, geographic area, and dataset. Future research should progress methods for impact pathways within the drivers exploitation and sea-use change, and effects on ecosystem biodiversity and genetic biodiversity.

The study examines the governance of low trophic species mariculture (LTM) using Sweden as a case study. LTM, involving species such as seaweeds and mollusks, offers ecosystem services and nutritious foods. Despite its potential to contribute to blue growth and Sustainable Development Goals, LTM development in the EU and OECD countries has stagnated. A framework for mapping governance elements (institutions, structures, and processes) and analyzing governance objective (effective, equitable, responsive, and robust) was combined with surveys addressed to the private entrepreneurs in the sector. Analysis reveals ineffective institutions due to lack of updated legislation and guidance, resulting in ambiguous interpretations. Governance structures include multiple decision-making bodies without a clear coordination agency. Licensing processes were lengthy and costly for the private entrepreneurs, and the outcomes were uncertain. To support Sweden’s blue bioeconomy, LTM governance requires policy integration, clearer direction, coordinated decision-making, and mechanisms for conflict resolution and learning.

Although rebound effects are well-known as a phenomenon, the question of how to avoid and minimize rebound effects have largely been ignored in practical policy. In this study, five concrete cases of measures and policies in the transport sector illustrate primary effects, rebound effects and possible strategies to avoid or minimize rebound effects. The cases were explored and analyzed in a series of workshops involving in total 15 researchers and societal actors. In addition to the net impact of primary and rebound effects, factors such as the time horizon and the reversibility of the effect may also be important for the evaluation of measures and policies. To detect and avoid rebound effects - and to assess the effectiveness of a policy - a system perspective is needed rather than a narrow sector focus. When designing measures, broad system-wide strategies or specific measures addressing particularly emission-intensive activities tend to be most effective for avoiding rebound.

Seaweed is often touted as a blue economy resource with climate benefits. Several calls are made to scale the industry up and to use blue carbon financing to create additional incentives for the sector to expand. But how much of a climate crisis panacea is seaweed, and under which conditions can climate benefits be realized? The article reviews the literature on climate impacts from seaweed value chains and proposes a cradle-to-grave structure for carbon accounting in seaweed value chains. While the literature points towards several ways in which climate benefits can be generated, the evidence base for net negative emissions across the value chain is not robust enough to suggest seaweed value chains, by default, are a climate solution. Instead, climate effects depend on the specific production setup, product choice and the fate of the product on the market. Climate benefits can only be claimed by tracking blue carbon flows across whole life cycles and over time. Knowledge gaps relate to effects at sea, the role of temporarily locking carbon into products and the effects of introducing this resource to the market. Blue carbon financing should be directed only to setups proven to lead to additional and permanent carbon storage.

Harvesting beach-cast can help mitigate marine eutrophication by closing land-marine nutrient loops and provide a blue biomass raw material for the bioeconomy. Cost–benefit analysis was applied to harvest activities during 2009–2018 on the island of Gotland in the Baltic Sea, highlighting benefits such as nutrient removal from the marine system and improved recreational opportunities as well as costs of using inputs necessary for harvest. The results indicate that the activities entailed a net gain to society, lending substance to continued funding for harvests on Gotland and assessments of upscaling of harvest activities to other areas in Sweden and elsewhere. The lessons learnt from the considerable harvest experience on Gotland should be utilized for developing concrete guidelines for carrying out sustainable harvest practice, paying due attention to local conditions but also to what can be generalized to a wider national and international context.

Plastic packaging is a major contributor to the environmental impacts associated with the linear plastic production and consumption system due to the prevalence of short-lived single-use plastic (SUP) packaging. Deposit-refund system (DRS), as an alternative policy instrument to Extended Producer Responsibility in waste management, is deemed as a potentially promising way to address the failure of the current plastic waste management and facilitate circular plastic packaging production and consumption for food contact use. In this paper, two DRS scenarios for recycling and reuse respectively are explored, with PET trays for food-grade use in Sweden in focus. Their costs and benefits are investigated relative to the business-as-usual scenario over a 25-year period. Results show that the costs are greater than the benefits for the recycling scenario but not for the reuse scenario and that the benefit-cost ratio (1,67) of the reuse scenario is 2.3 times as high as that (0,73) of the recycling scenario. The distributive analysis reveals major cost drivers such as deposit handling and recycling in the recycling case and deposit handling, dishwashing and packaging in the reuse case and major cost takers such as materials industry and hospitality/supermarkets in both scenarios. However, the results are uncertain, as is indicated by sensitivity analysis. Several parameters with high uncertainty are identified and highlighted for system development and innovation.

Public acceptance of environmental compensation (offsetting) as a mechanism to address negative human impacts on biodiversity and ecosystem services is critical. Given that "in-kind/on-site" compensation is rarely possible, proposals must address trade-offs with respect to design. We measure Swedish citizens' support for compensation and analyze preferences for design attributes based on a choice experiment in which respondents choose between various compensation alternatives to address the hypothetical loss of green space due to urban development. We find citizens' support for compensation is high, but the activity causing the damage affects acceptance. Our model suggests that several design attributes affect choice but size of the compensation area was valued highest, both in relative and absolute terms. Further, our results suggest that compensation should be primarily focused on creating or improving biodiversity and nature values in order to be in line with public preferences. Additionally, choice depends on interactions between attributes: a larger compensation site matters more when it is relatively further away; and the importance of size and distance from damage depends on whether compensation type focuses on nature or recreational values. Observable characteristics such as a respondent's age, income and education affect compensation design preferences, but perceptions and previous experiences have the largest effect on choice. Our findings suggest that public preferences are consistent with many of the general recommendations found in guidance documents, but local context may argue for alternative priorities with respect to certain species, habitats, and/or the wellbeing of certain groups. To engender broad support, compensatory offsets will need to balance scientific rigor with transparent involvement of the public.

A blue-green bioeconomy revolution is underway in Europe, with particular attention being paid to the development of new or underutilized marine biomass resources. The wild harvest and mariculture of low-trophic non-fed species of marine biomass may be contributing to circular economies, the mitigation of environmental problems such as eutrophication and climate change through the uptake of nutrients and carbon, while also recovering finite phosphorus from marine coastal environments, thus contributing to food security. The present study provides a cradle-to-gate life cycle perspective on seven established or innovative/emerging marine biomass utilization cases in Sweden: mariculture of sugar kelp, blue mussels, and ascidians and the harvest of invasive Pacific oysters along the Skagerrak coast, the mariculture of blue mussels in the Baltic sea, the harvest of common reed in the Stockholm archipelago, and the harvest of beach-cast seaweed in Gotland. Results showed that the mariculture cases were found to contribute to eutrophication and climate impact mitigation (at gate). All cases were found to contribute to closing the loop on phosphorus by enabling recovery from marine or coastal environments, bridging marine–land flows, all while performing well from an environmental perspective with a relatively low cumulative energy demand and low carbon and nutrient footprints. This highlights the potential of low-trophic biomass to contribute to phosphorus security in the future, and demonstrates the value of industrial ecology tools such as LCA in support of this imminent Decade of Ocean Science for Sustainable Development. 

Anthropogenic consumption of nitrogen (N) and phosphorus (P) has pushed their respective planetary boundaries beyond a safe operating space causing environmental problems, and simultaneously, the depletion of finite mineral P resources is of growing concern. Previous research has found that marine biomass such as kelp, reed and mussels have a high potential for taking up N and P, which could potentially contribute both to alleviating environmental problems and recirculating P from marine environments back to human consumption systems. This paper thus examines these nutrient flows and the extent to which marine biomass can contribute to close the loop. The study utilizes an element flow analysis (EFA) to establish the mapping of N and P flows and explore plausible scenarios of biomass utilisation by 2030 and 2050 for P loop closure in Sweden. The current uptake of P and N through the seven marine biomass cases (mariculture of mussels on both the Swedish east and west coasts, kelp and ascidians and the harvest of wild oysters, beach-cast and reed) contributes to 1.1% and 0.3% respectively of the full loop closure (relative to 2016 loading). Approximately 22% of the total P (and 23% N) uptake (in the biomasses) is currently being used in products, while the rest remains unused. The plausible future scenario for 2050 expects to contribute to around 10% P and 2.8% N loop closure (relative to 2016) if all nutrients in the uptake are used.

Environmental compensation should address negative impacts from human activities on nature, including loss of biodiversity and ecosystem services. However, successful compensation, achieving no net loss, requires broad quantitative information on different types of losses and gains. We find that the scope of compensatory schemes varies in what is considered compensable, which makes it challenging to apply a conceptual approach consistently across schemes with different needs. We propose a flexible yet structured framework for determining which values should be compensated and how. Our framework focuses specifically on habitat deterioration and is illustrated with a case study involving loss of eelgrass habitat. The framework helps identify compensation needs and selects among suitable compensation options, merging science-based information with normative issues and local concerns. By integrating the ecosystem services cascade model, it encompasses aspects from biodiversity structure to human wellbeing. The framework prefers in-kind compensation because this targets the structure level and thus meets compensation needs in all subsequent levels of the cascade model; further, it is more likely to capture non-instrumental values (i.e. in nature) and reduce exposure to uncertainty. We highlight the importance of spatial aspects of ecosystem functions, services and their subsequent impacts on wellbeing. Although our selection hierarchy assumes a "similar and nearby" principle for habitat restoration (preference for in-kind/on-site), this criterion is not universal. We underscore the hierarchy's implicit normative assumptions and suggest that apparent disagreement about who should benefit may be traced to an unresolved conflict between egalitarianism and utilitarianism.