Species Selection and Cultivation

Several critical obstacles exist in the area of species selection and cultivation that are common for low-carbon products. See the chapter, “Cultivation and Drying Considerations” for more information.

This section summarizes several gaps that need to be solved for widespread adoption needed to have climate impact- these range from the development of more efficient processing methods to resolving the technical performance of seaweed-based bioplastics.

Processing and Conversion Technologies

Processes are still not optimized because of low volume

Achieving high yield and consistent quality through process optimization will play a critical role in developing products that are competitive.

Conversion techniques have environmental challenges that need to be addressed

Traditional biopolymer extraction methods often involve harsh chemicals (for example, sodium carbonate and hydrochloric acid are often used in the alginate isolation process). Additives such as plasticizers (e.g. glycerol) and surfactants can also result in additional health and environmental concerns. Less impactful extraction technologies have been found to improve alginate extraction yield and quality, but at a higher cost (Saji et al., 2022).

Conventional processing methods can adversely affect the mechanical properties of biopolymers

Processing biopolymers as conventional thermoplastics through conventional, highly scalable processing methods such as compression molding or extrusion can degrade biopolymers, impacting mechanical properties (Negrete-Bolagay et al., 2024). This can be addressed by blending biopolymers with other polymers (Torrejon et al., 2025).

Final Use

Seaweed-based bioplastics do not match the technical performance of incumbent products

A significant hurdle is matching the technical properties of seaweed-based bioplastics (e.g., tensile strength, water resistance, barrier properties) with those of existing conventional plastics, which consumers and manufacturers expect (World Bank, 2023).

Seaweed-based plastics must strike a balance between goals of being easily biodegradable with being long lasting and recyclable

The goal of designing home-compostable, single-use alternatives often conflicts with the aspiration to develop long-lasting, recyclable materials where the goals are likely to develop pellets that can be mold-injected to form various products using the same machinery that conventional plastics use (World Bank, 2023).

This section summarizes gaps that need to be solved for decarbonization because seaweed-based bioplastics cannot displace conventional plastics at volumes relevant to emissions reduction while biomass costs remain high, supply chain compatibility with existing manufacturing infrastructure is unproven, and market niches where performance and price tolerance align have not been identified.

The current cost of seaweed biomass is too high to produce price-competitive goods for many new markets
This is especially true when competing with commodity or commodity-derived products like plastics.

Seaweed-based bioplastics haven’t integrated into plastic supply chains

For seaweed bioplastics to achieve scale, they must seamlessly integrate into existing plastic manufacturing machinery and processing lines, including injection molding, extrusion, film blowing, and thermoforming. This requires developing compatible seaweed-based pellets (World Bank, 2023).

The plastic industry is extremely complex, making a transition to seaweed-based plastic challenging

The vast array of configurations and required functionalities in the plastics market (from food packaging to rigid parts) means that selecting and focusing on desired market niches is crucial, but also complex (World Bank, 2023).

Bioplastics from seaweed remain largely premium niche products in low-price, high-volume markets such as films and packaging

Seaweed-based bioplastic producers are in an early stage of development, with limited raw materials and high development costs. Scaling up the raw material pipeline and  product development will be key to moving out of the premium niche (World Bank, 2023).

This section summarizes gaps that need to be solved for decarbonization because the scale-dependent carbon benefit of seaweed bioplastics cannot be credibly communicated to consumers or industrial buyers until independently verified full-system-boundary LCA data exists at commercial scale.

Resistance to change from the industry

Current industry interests resist the need for novel approaches to construction. A risk averse culture has developed partially due to user concerns and perceptions on the risks of using an unfamiliar material. There is a strong preference among the industry for the status quo of synthetic and mineral-based materials.

Consumer Adoption

There is a lack of public awareness about bioplastics and their benefits

This lack of awareness needs to be overcome both among industrial users as well as the end customer. In addition, while consumers increasingly value sustainability, they may not be willing to pay a “green premium” for commodity items such as packaging (Rosenboom et al., 2022).

Seaweed-based bioplastics still must make the case for reduced climate impact

Analysis of carbon mitigation potential shows that at pilot scale, the level of climate benefit from seaweed-based bioplastics is low; at scale, there should be impact. A clear assessment of the benefits of seaweed-based bioplastics needs to be made and communicated to prevent accusations of ‘greenwashing’.

This section summarizes gaps that need to be solved for decarbonization because without a carbon price on conventional plastics, incentives for biobased alternatives, and independently verified LCA standards, seaweed bioplastics remain structurally disadvantaged regardless of their actual emissions performance, and policy-makers lack the evidence base needed to design instruments that support the transition.

There are not enough incentives to accelerate the development of seaweed-based bioplastics or disincentives to reduce our reliance on petroleum-based products

Given the nascency of the seaweed-based bioplastics sector, there is a lack of clear legislation and governance to incentivize sustainable seaweed farming practices and facilitate new farming licenses impedes growth as does the absence of incentives to develop bioplastics (outside of those for single use plastics). This, combined with the lack of a carbon tax to disincentivize petroleum-based plastics, makes it a challenge to be cost competitive (World Bank, 2023).

There is a lack of standardized, comparable LCA data to support policy from a climate impact perspective

There is a general lack of good quality, comparable data from LCA studies against which to assess and validate results and make predictions about scale. This gap means that policy makers who require independently verified LCA data before supporting policy from a climate lens cannot currently satisfy that requirement.