Marine biomass for a circular blue‐green bioeconomy? A life cycle perspective on closing nitrogen and phosphorus land‐marine loops

Abstract

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.

The Role of Organic Fertilizers in Transition to Sustainable Agriculture in the MENA Region

“…Also, rather than considering fertilizer application merely from the view of inputs and short-term yields, and besides measures such as C:N ratios, we need to take on a more holistic view, looking at how choice of fertilizer relates to nutrient absorption efficiency, drought resistance of root systems [143], soil health, land degradation, water management and ecological intensification. Future shortages of P [144][145][146], loss of arable land [37], decline in soil carbon [147], as well as widespread decline in soil fertility driven by industrial practices in agriculture, point to the important role of organic fertilizers. However, availability of organic material is constrained by competing demands on biomass and land for industrial and carbon sequestration purposes, while contamination of organic waste and wastewater [10,118,148] poses an issue for possible circular approaches.…”

Health Benefits, Food Applications, and Sustainability of Microalgae-Derived N-3 PUFA

“…This industry mainly produces extracts for processed foods and other industries, such as cosmetics and medicine, while the ready-to-use of raw biomass has been widely generated as well. Similar to other industries, a sustainable algal industry can create a great value chain, which is an important step towards bluegreen bioeconomy [266,267]. The socioeconomic impact of microalgae industry can be assessed and predicted from numerous aspects, including but not limited to societal factors, such as education, technical training, new businesses, startup companies and supports, financial investments, new sources of functional ingredients, and the improvement of life quality, and thus reduced health care costs associated with the consumption of microalgal products.…”

Stakeholder Perspectives on Blue Mussel Farming to Mitigate Baltic Sea Eutrophication

“…Typically, eutrophication is managed using a linear paradigm whereby the external inputs of nutrients from the catchment are reduced. New approaches based on internal (in-situ) measures and circular thinking (e.g., [4][5][6][7]) are needed. At present, internal measures to capture and/or remove nutrients directly from the waterbody are rarely employed, but they are desirable as they offer greater possibilities for circularity and nutrient reuse.…”

“…Most efforts to date towards a goal of circular nutrient management in the Baltic Sea region have focused on nutrient reuse in the catchment [5,6]. Today, there is increasing awareness that marine biomass may also have a role to play in the circular nutrient economy [7].…”