National Organic Standards Board Materials Subcommittee Proposal 

Marine Macroalgae1 in Crop Fertility Inputs 

August 11, 2020 

Summary: 

This proposal brings forward an annotation to marine macroalgae used as crop fertility inputs to provide 

parameters on harvesting addressing conservation areas, bottom trawling, protecting reproduction of 

the population and ecosystem functions, biomass and architecture, and bycatch. 

Introduction and Use: 

Seaweeds are classified into three broad groups based on pigmentation: brown, red, and green; 

respectively, Phaeophyceae, Rhodophyceae and Chlorophyceae (TR 2016 lines 103-4), and all three 

classes are used in organic fertilizers2

. Seaweeds are also called macro-algae, distinguishing them from 

micro-algae (Cyanophyceae) which are microscopic in size and often unicellular (TR 2016 lines 108-110). 

Seaweeds used in synthetic aquatic plant extracts and in nonsynthetic products, namely meal, are 

macroalgae. 

Marine macroalgae are used in extracts as foliar fertilizers or as soil conditioners. They also are used as 

a foliar/soil feed or transplant solution and seed treatment. The material is absorbed into the plant and 

acts as a growth promoter (TR 2006 lines 63-6). Marine macroalgae is widely used by producers. During 

the most recent sunset review of aquatic plant extracts, certifiers reported high numbers of growers 

listing these materials on their Organic System Plans. 

Background: 

In 2015, the board had a lengthy sunset review, and as part of that process reviewed marine materials in 

the Handling (seaweeds for human consumption), Crops (aquatic plant extracts for fertilizers), and 

Livestock (kelp for feed) subcommittees. In the Crops Subcommittee, the majority of initial comments 

were in favor of keeping aquatic plant extracts on the National List. During the fall public comment 

period, the Subcommittee identified concern about potential overharvesting. Extensive public comment 

was received on this issue. At the end of the fall 2015 meeting, the board recommended keeping 

aquatic plant extracts on the National List; however, the vote was divided. The board consequently 

prioritized review of this topic and determined that a Technical Evaluation Report (TR) was needed on all 

the marine plants used in organic production across the Crops, Livestock, and Handling Subcommittees. 

The board received the limited scope TR on Marine Plants and Algae in summer 2016. Subsequently, 

the Handling Subcommittee published a fall 2016 Discussion Document for Marine Algae Listings on the 

National List. In it, the board stated that “it is within this context of a desire to allow use of marine 

plants and algae in organic production, while at the same time ensuring long term sustainability, that 

the marine materials on the National List must be reviewed”. The board solicited public comment on 

addressing naming conventions as well as developing guidelines for wild harvested seaweeds. As a 

result, a spring 2017 Proposal on Marine Algae Listings was posted in the Crops Subcommittee, which 

was virtually identical to a similar proposal in Handling, and it tried to address classification and 

nomenclature. In the Crops section, a proposal was put forth to limit aquatic plant extracts to those 

1 For the purposes of this proposal, the term “marine macroalgae” is used to refer to marine plants, seaweed, and 

marine vegetation. 

2 The 2016 TR lists species used in fertilizers and their harvest regions. This list can also be found in on page 3 of 

the fall 2018 Discussion Document on this topic. 

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derived from brown macroalgae. Public comment revealed there were numerous products containing 

red, green, and brown macroalgae. In Handling, significant public comment was received stating 

stakeholders needed more time to address the classification and nomenclature issues. The Handling 

Subcommittee re-posted the Discussion Document for the Fall 2017 but received no significant 

additional public comment. 

The work agenda item was moved to the Materials Subcommittee, and the board explored new 

approaches to addressing concerns about environmental impact. The Materials Subcommittee posted a 

fall 2018 Discussion Document proposing that all marine macroalgal ingredients used in organic crop 

production be certified organic. The spring and fall 2019 Discussion Document solicited comments on 

the question of organic certification or an annotation specifying harvest methods. To further explore 

this complex topic, the board convened an expert Panel on Marine Materials used in crop inputs at the 

fall 2019 meeting. 

The goal of the board’s work on this topic is to take a precautionary approach to ensuring that both 

synthetic and nonsynthetic forms of marine macroalgae used in fertilizers are not “harmful to ... the 

environment” by adversely impacting the ecosystem provisioning of the marine environment. 

Relevant Areas of the Rule, NOP Guidance, NOP Policy Memo, and NOSB Policy and Procedures 

Manual: 

OFPA Section 6517 [National List] (c) [Guidelines for Exemptions or Prohibitions] (1)(a)(i) and (2)(a)(i) 

which allows for the prohibition of synthetic or nonsynthetic substances, respectively, that would be 

“harmful to ... the environment.” 

§205.2 Terms defined. 

Organic production. A production system that is managed in accordance with the Act and regulations in 

this part to respond to site-specific conditions by integrating cultural, biological, and mechanical 

practices that foster cycling of resources, promote ecological balance, and conserve biodiversity. 

§205.601 Synthetic substances allowed for use in organic crop production. 

In accordance with restrictions specified in this section, the following synthetic substances may be used 

in organic crop production: Provided that, use of such substances does not contribute to contamination 

of crops, soil, or water... 

(j) As plant or soil amendments. 

(1) Aquatic plant extracts (other than hydrolyzed) –Extraction process is limited to the use of potassium 

hydroxide or sodium hydroxide; solvent amount use is limited to that amount necessary for extraction. 

§205.207 Wild-crop harvesting practice standard. 

(a) A wild crop that is intended to be sold, labeled, or represented as organic must be harvested from a 

designated area that has had no prohibited substance as set forth in §205.105, applied to it for a period 

of 3 years immediately preceding the harvest of the wild crop. 

(b) A wild crop must be harvested in a manner that ensures that such harvesting or gathering will not be 

destructive to the environment and will sustain the growth and production of the wild crop. 

§205.200 General. 

Production practices ... must maintain or improve the natural resources of the operation, including soil 

and water quality. 

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7 U.S.C. 6518 National Organic Standards Board, 6518 (b) Board composition, (4) 

three shall be individuals with expertise in areas of environmental protection and resource 

conservation; (6) one shall be an individual with expertise in the fields of toxicology, ecology, or 

biochemistry. 

NOP 5022, effective July 22, 2011, Guidance: Wild Crop Harvesting provides details to clarify §205.207, 

including: 

Section 205.200 states that production practices must maintain or improve the natural resources of an 

operation under organic certification. This applies to all types of organic certification, including wild 

crops. Unmanaged, untrained and uninformed harvesting of wild products from a wild habitat without 

maintaining or improving the natural resources can disqualify the wild products from organic 

certification. 

Additionally, the Guidance states: 

1. A description of the proposed ecosystem management and harvesting practices, the impact of 

their proposed harvesting on the long-term viability of the wild species and on the area’s 

ecosystem, and information on any equipment planned for use or being used to harvest and 

manage the wild-crop and ecosystem. 

a. This should include a description of the monitoring system that will be used to ensure 

that the crop is harvested in a sustainable manner that does not damage the 

environment, including soil and water quality. 

2. A list of any rare, threatened, or endangered terrestrial or aquatic plants or animals that occur in 

the harvest area. 

a. The presence of rare, threatened, or endangered species in a wild harvest area does not 

automatically disqualify an operation from organic certification, but any potential or 

actual impacts need to be described and addressed. 

b. If there are potential or actual negative impacts resulting from the wild crop 

management and harvesting, actions that address and correct these impacts need to be 

described, implemented, and monitored. 

3. The procedures employed that prevent contamination from adjoining land use or other point or 

non-point sources contamination. 

4. The training provided and the procedures employed to ensure that all collectors harvest crops 

in accordance with the OSP and in a manner that does not damage the environment. 

NOP 5020, effective 1/15/16, Guidance: Natural Resources and Biodiversity Conservation clarifies 

organic regulations at 7 CFR 205.200 that states, “to maintain or improve the natural resources of the 

operation....”. 

NOP Policy Memo 12-1, Production and Certification of Aquatic Plants, issued September 12, 2012 

provides further clarification as follows: 

This policy memorandum is issued as a reminder that aquatic plants and their products may be certified 

under the current USDA organic regulations. Certifiers and their clients may use the USDA organic 

regulations, including the National List of Allowed and Prohibited Substances at 7 Code of Federal 

Regulations (CFR) 205.601-205.602, as the basis for the production and certification of cultured and wild 

crop harvested aquatic plants. 

While current USDA organic regulations specifically exclude aquatic animals from organic certification, 

no such exclusion exists for aquatic plants. Further, some parts of the USDA organic regulations 

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specifically address aquatic plant production. For example, some aquatic plants, such as kelps and 

seaweeds, are listed in 7 CFR 205.606 of the USDA organic regulations, allowing their use in non-organic 

form when certified organic forms are not commercially available. Producers and certifiers are required 

to comply with the USDA organic regulations when producing or certifying cultured and wild crop 

harvested aquatic plants. 

The use of ground and surface waters, ponds, streams, or other waterways for aquatic plant production 

may be regulated by Federal, State, or local authorities. Aquatic plant producers should consult with 

Federal, State, and local authorities to ensure compliance with all applicable laws, in addition to the 

USDA organic regulations, regarding the use of synthetic substances and other materials in ponds and 

waterways. Also, under 7 CFR 205.200, aquatic plant producers must ensure, and certifying agents must 

verify, that production practices maintain or improve the natural resources of the operation, including 

soil and water quality. 

NOSB Policy and Procedures Manual, Principles of Organic Agriculture Organic agriculture, adopted 

2001, 1.1 states: Organic agriculture...is an ecological production management system that promotes 

and enhances biodiversity, biological cycles, and soil biological activity. 

Public Comments: 

Public comments over the past several years have been diverse on this topic and range from support for 

organic certification as an appropriate tool to address environmental impacts of harvesting, to caution 

against setting a precedent of certifying an input ingredient, to concerns that certification could amount 

to greenwashing by inadequately addressing environmental impact, to sentiments that the industry 

does not need further regulation. A broad review of public comments can be found in the earlier 

discussion documents referenced above. 

The 2019 spring and fall discussion document asked stakeholders to provide feedback on the possibility 

of requiring organic certification for marine macroalgae input ingredients, presented standards from 

other certifiers and third-party entities certifying sustainable seaweed, solicited numbers of crop input 

products approved for use that currently contain certified organic marine algae ingredients, and 

inquired if farmed algae is used in any products. Public comments covered all questioned posed. 

Although several certifiers were skeptical about the ability to certify wild aquatic systems, it was also 

noted that this is already being done for handling and livestock uses of marine macroalgae. Importantly, 

material review organizations reported that there are some crop fertilizer products now that formulate 

with certified organic marine macroalgal ingredients. Farmed algae do not appear to be used, likely 

given the high cost of seaweed aquaculture compared with the large volumes of material needed for 

fertilizers3

. 

While some worried about increased scrutiny of additional nonsynthetic inputs, others said some 

natural inputs likely deserve more scrutiny for their environmental impact. Opposition to requiring 

organic certification was centered on precedent setting and the inconsistency of requiring certification 

for one type of input but not others (though there were also some who felt marine macroalgae should 

not be certified organic as its harvest can never meet the standard of not destructive to the 

3 Theuerkauf et al. discuss the potential of seaweed aquaculture to mitigate seagrass beds and kelp forests losses 

globally as a result of overharvesting and other human activities (2019). See Buschmann et al. on the prospects of 

seaweed cultivation to alleviate increasing harvest pressure, particularly of Macrocystis pyrifera (2014). 

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environment). One commenter supporting certification as a tool stated that if organic certification is 

important for food, the organic community should also see it as viable for inputs. They noted, “we do 

not believe that requiring organic certification of marine material inputs would create the universal 

expectation that all crop inputs, such as manure and mulches, be certified organic”. Another 

commenter shared that “sourcing of inputs, including those from natural resources, can have significant 

impact on the sustainability of agricultural systems, and NOSB is responsible for making 

recommendations for inputs on the National List that would not harm the environment”. 

Some public comment supported using annotations to the National List and definitions as the best 

means for developing clear standards rather than requiring certification. NOP guidance would provide 

additional information on implementation, as well as training areas for inspectors. It was felt that an 

annotation could specify parameters for harvesting and would be more enforceable than attempting to 

establish such parameters through guidance complementing an organic certification requirement. A 

material review organization said they could hire staff capable of reviewing an annotation and 

conducting on-site inspections. 

One public commenter and marine biologist proposed “some key aspects to be considered within the 

definition of ‘not destructive to the environment’: a) the amount that can be harvested from an area; b) 

the method and timing of harvest; c) the impact of the harvest on the structure and reproduction of the 

plants themselves; d) the consequences of the changes in the canopy for other species; e) the direct 

removal of non-target species (by-catch); and the ability of the ecosystem to f) remain resilient in the 

face of many challenges (climate change, invasive species) and g) maintain essential functions and 

services”. Another marine scientist emphasized the need to focus on the habitat marine macroalgae 

provide when considering the effects of harvesting. 

Some stakeholders suggested prohibiting specific species, regions, or harvest methods might be an 

option. Some felt government regulations are adequate, though it was acknowledged that they do not 

typically involve on-site verification and enforcement varies. One stakeholder suggested that more 

information is needed about existing legal frameworks in countries where most marine macroalgae used 

in fertilizers is harvested. 

The board particularly requested industry participation and heard from a number of harvesters in the 

fall 2019 public comments. Several harvesters stated that the harvest of rockweed, for example, is well 

regulated and does not negatively impact the marine environment. One harvester explained that they 

follow biomass assessments, closed areas, minimum cutting heights, and periodic auditing. They 

indicated that if the wild crop standards for organic certification as applied to marine macroalgae feed 

for livestock remained the same for certification of macroalgae for fertilizer products, they would 

support organic certification. Another harvester said that while not against organic certification, they 

prefer applying the commercial availability clause instead. One harvester and processor stated that 

annual regrowth of the seaweed extracted exceeds the amount harvested. A company based in Ireland 

explained its compliance process with each of its harvesters, which includes hand harvesting to preserve 

“the balance of the ecosystem without damaging environmental issues that could arise from this 

activity”. 

An industry task force was developed by one association to foster discussion around this topic. There 

was a request for more documentation of the need for monitoring harvests to avoid environmental 

impact. In addition, the stakeholder said that more information on global harvesting rates is needed. As 

noted by the Food and Agriculture Organization, “About 25 million tonnes of seaweeds and other algae 

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are harvested annually for use as food, in cosmetics and fertilizers, and are processed to extract 

thickening agents or used as an additive to animal feed.” Unfortunately, accurate global harvest rates 

for marine macroalgae across all uses is difficult to obtain. Equally, information on the impact of 

harvests for fertilizers is unavailable on a global level (see the review of the scientific literature below for 

more information). 

One public commenter provided a comprehensive overview of all marine materials used in organic 

production across macroalgal and fish uses in Crops, Livestock, and Handling. Although some public 

comment suggested we look at all marine uses across all subcommittees under one work agenda item, 

there are practical limitations that make that challenging. Significant differences exist between fish and 

marine macroalgae and between Handling and Livestock uses. Each marine material on the National List 

represents a discreet use that warrants individual attention. If the work agenda item were too large, it 

might preclude meaningful progress. 

Stakeholders asked the board to create standards that cover existing certified organic marine macroalgal 

materials. Some were concerned that the board not create a higher standard for crop fertility uses of 

marine macroalgae than for human consumption and livestock feed. Alternatively, it could be argued 

that most seaweeds used in organic handling and all used in organic animal agriculture receive some 

measure of oversight and protection through their certification to the wild crop standard. The 

inconsistency lies in using the same, unverified input in fertilizers that is certified organic in handling and 

livestock uses. Additionally, the wild crop standard is necessarily general to cover the wide range of 

crops it can include. But in its generality, it does not give guidelines for how the standard operates in 

complex marine environments. As one commenter said, the existing wild crop standards “are very 

limited” and “do not provide sufficient metrics for certifiers”. Given the complexity of this topic, this 

proposal is intended as a first step, with subsequent explorations of marine macroalgae uses in Handling 

and Livestock. Annotations for Handling and Livestock uses will be the next area the Materials 

Subcommittee investigates. 

In conclusion, one harvester of certified organic kelp meal noted “agriculture by its very nature causes 

environmental harm, even organic agriculture disrupts the natural succession of the ecosystem”. 

Organic agriculture is founded on practices intended to minimize its environmental impact and harm. 

The commitment organic farmers demonstrate to soil and water conservation, fostering biodiversity, 

and limiting negative impacts of synthetic chemicals through a host of practices relates to a desire by 

many to source inputs reflecting similar values. 

Discussion: 

Review of the Literature 

A review of the literature on the environmental impact of commercial seaweed harvesting varies in its 

findings. The 2016 TR raised concerns about the potential for negative environmental impacts on 

marine ecosystems from macroalgal harvesting. Some examples noted in the 2016 TR were specific to 

species used in organic crop fertility inputs and aquatic plant extracts. For example, in mechanical 

harvesting in Iceland, as with other areas where Ascophyllum nodosum and Laminaria digitata are 

harvested commercially, ecological concerns about changes in species diversity resulting from 

harvesting have been noted (TR 2016 lines 892-6). The cited paper states “industrial harvesting of the 

seaweed Ascophyllum nodosum in the Bay of Breioafjorour inevitably leads to the death of huge 

numbers of invertebrates, including species that are important food for birds” (Ingolfsson 2010). In 

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Nova Scotia, commercial yields of rockweed are maintained. A comprehensive assessment of impacts 

performed by industry or third-party research proving harvest rates are not detrimental to the rockweed 

marine community is lacking. Estimated recovery times based on percentages of rockweed removed 

vary between publications (TR 2016 lines 597-600). Additionally: 

There is one species of red algae and two species of brown algae growing along the 

coasts of the United States that have gained attention as ecologically threatened in 

recent years. They are respectively, Irish moss (Chondrus crispus), rockweed 

(Ascophyllum nodosum) and giant kelp (Macrocystis pyrifera). These plants are 

economically important and drive several seaweed industries including cosmetic 

products, nutraceuticals, fertilizers and hydrocolloids. Fertilizer applications are similar 

to farmyard manure, but may also include extracts and foliar applications (Chojnacka, 

2012). 

Kelp and rockweed, are foundational species forming large expansive marine habitats 

supporting a diverse range of wildlife, including other algal species, marine animals and 

many species of protozoans and bacteria (Seeley and Schlesinger, 2012). Without a good 

accounting of all of the species present it is hard to predict the effects of harvesting 

rockweed and kelp on each ecological niche. Thus, it has been important to recognize 

that sustainable seaweed production perceived as reproducible harvest capacity, may 

not guarantee the sustained subsistence of each resident species. Although not part of 

any agricultural waste stream, extracts from wild-harvested kelp and rockweed are 

allowed for use in organic production as soil amendments (§205.601(j)(1)). [TR 2016 

lines 522-535]. 

Even within the 2016 TR, differences of opinion about the environmental impacts of harvesting were 

noted within the scientific community. For example: 

One study addressing the major components of the resident fish community in the rocky 

intertidal zone after rockweed harvest found no evidence linking rockweed harvest to 

changes in the ichthyoplankton component or the juvenile and adult fish of that 

community (van Guelpen and Pohle, 2014). In a summarized review of selected work, a 

researcher at the University of Maine also concluded that the effect of 17% rockweed 

harvest on some species including seabirds was negligible (Beal, 2015). [TR lines 326-31] 

The TR goes on to explain that: 

Notwithstanding, rockweed has an important role as habitat, as food and as a nutrient 

source supporting a community of organisms that inhabit its “forests.” Any cutting of 

rockweed can produce an effect on the supported eco-communities. Furthermore, 

many aspects of this ecosystem have not been elucidated, encouraging more precaution 

as the brown algae “forestry” industry grows into the future (Seeley and Schlesinger, 

2012). [TR lines 356-60] 

Since 2016, the board has received numerous public comments by marine macroalgae experts and other 

stakeholders, and these have included myriad references to the academic literature. A reading of the 

comments and their citations reveals the many views on the environmental impacts of harvesting 

marine macroalgae. Nevertheless, it cannot be said that removing a wild native species from a wild 

native ecosystem, as in the case of commercial marine macroalgal harvests, has no impact on the 

environment. As explained above, the extent to which harvesting causes negative environmental 

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impacts is contested within the literature4. There are certainly papers that will state views counter to 

those cited below, and interestingly, the same papers are quoted to support competing claims5

. It is not 

the goal of this proposal to argue over whose science is right. 

The literature review on the environmental impacts of harvesting is not intended to suggest that effects 

cannot be at least partially mitigated or that harvesting should not occur. Rather, the information was 

requested in public comments, and it is presented to demonstrate the complexity of the issue and to 

address claims made in some public comments that harvesting has little effect on the environment. 

While it is not possible to provide a comprehensive analysis of peer-reviewed research here and there 

are numerous other articles that could have been cited, the following review of the scientific literature 

provides the technical data to support this proposal. 

“Canopy-forming seaweeds, including kelps, rockweeds and many red seaweeds are widely 

acknowledged as foundation species that form important three-dimensional structure in marine coastal 

environments which contribute important functions and services” (Lotze et al. 2019). These include 

primary and secondary production, production of detritus, nutrient cycling, carbon storage, nutrient 

retention, provision of food for biodiversity, biological links between marine ecosystems, habitat for 

year-round residents, foraging grounds, breeding and nursery areas, refugia from predators, coastal 

buffers from waves and storms, and filters for runoff (Ibid). “Despite the ecological importance of 

seaweed canopies and their long history of harvesting, relatively few studies have directly examined the 

effects of harvesting beyond the resource species itself on ecosystem structure, functions and services” 

(Ibid). The authors conclude that: 

harvesting canopy-forming seaweeds affects the morphology, canopy structure, standing stock 

and species composition of the foundation species which in turn affects their ecological roles in 

marine ecosystems (Table 2). The magnitude and range of ecosystem impacts depend on the 

species being harvested, the harvest methods employed, the intensity of biomass removal and 

its spatial and temporal extent (Supplementary Text S2 and Table S2.1). The broader ecosystem 

effects further depend on the recovery of seaweed fronds and regeneration of seaweed 

canopies after harvesting, and the ability of associated flora and fauna to recolonize and 

reorganize associated communities. (Ibid) 

Schmidt et al.’s (2011) study of ecosystem services of eelgrass and rockweed found that: 

marine vegetation provides important habitat, nitrogen, and carbon storage services, yet the 

extent of these services depends on the foundation species and its architecture. Changes in 

canopy structure will therefore have profound effects on associated food webs and ecosystem 

services. Thus, as increasing human pressures on coastal ecosystems threaten the continued 

supply of essential functions and services, the protection of marine vegetated habitats should be 

a management priority. 

Mac Monagail et al. (2017) offer a comprehensive analysis of the environmental impacts of marine 

macroalgal harvesting, including the effects of over-exploitation on biomass and coastal habitats. They 

state, “as is the case with the use of all natural resources, the wild harvest of seaweeds inevitably has 

ecological implications for the species targeted, and the associated 

4 For example, Phillippi et al.’s (2014) study indicates potential beneficial impacts of Ascophyllum nodosum 

harvesting on invasive crabs. The paper acknowledges that “human utilization of any natural resource involves 

ecological implications not only for the species harvested, but for its associated community as well” (Ibid). 

5 See for example Sharp and Pringle 1990, Sharp et al. 2006, Ugarte 2010, and Ugarte and Sharp 2001, among 

others. 

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community of flora and fauna, leading to varying degrees of change” (Ibid). Additionally, “Poorly 

managing resources, such as opportunistic harvesting, excessive removal of holdfast material (reducing 

regeneration), trampling and enhanced grazing by herbivores all place additional stresses on the 

resource, while near denudation of a seaweed bed is perhaps the most extreme case of direct impact on 

the community (Ibid)”. The authors point out that sustainable harvesting practices are possible and 

collaborations between scientists and harvesters have led to the development of best practices in some 

places. 

The impacts of hand versus mechanical harvesting are contested, but mechanization increases the 

amount of biomass removal in the same amount of time. In Ireland, review of potential mechanization 

cautioned that it is “essential to develop a suitable management scheme to ensure sustainable 

exploitation of natural resources and continuous integrity of marine habitats” (Werner and Kraan 2004). 

In a separate study in Ireland, even traditional hand harvesting resulted in a difference in cover of 

associated algal species following the removal of the target species (Kelly et al. 2001). Additionally, 

there were seasonal differences in “the abundance of periwinkle Littorina obtusata in hand harvesting 

(Ibid). Krumhansl et al. (2017) found that small-scale, “artisanal” harvesting of Macrocystis pyrifera in 

the Pacific Northwest had a minimal impact on kelp recovery rates. Lotze et al. (2019) note: 

Any harvesting method will affect the extent and three-dimensional structure of a seaweed 

canopy, but the magnitude and range of consequences will depend on the gear type, the 

harvest intensity and scale, and the cutting methods applied. While mechanical clear-cutting or 

trawling will remove most of the canopy with years to decades needed for recovery, even lower 

level hand-harvesting changes canopy structure through a truncation of larger, older and more 

voluminous fronds... Cutting height plays a crucial role in frond regrowth, such as for perennial 

rockweed, and repeated cutting can change the branching, size, and density of seaweed fronds. 

Such changes in the amount and structure of the seaweed canopy will affect the quantity and 

quality of habitat provision and community organization”. 

Calculations of the ecological effects of kelp trawling in Norway 

show that kelp trawling reduces primary and secondary production substantially within the kelp 

trawled tracks. Primary production is reduced with 45 % and secondary production with 70 to 98 

%... Observations indicate that diversity of flora and fauna will be reduced within the trawled 

area. The diversity will probably not recover until the mean age of the plants reach the mean 

age of the large kelp plants in untrawled kelp forest. Mean age increases with increasing latitude 

and is about 7 years in mid-Norway, where the kelp forest has optimal growth conditions and is 

well developed. With a trawling interval of 5 years, the kelp forest within mid-Norway will not 

be recovered with respect to species diversity until next trawling. (Rinde et al. 2006) 

In a study of biomass and productivity of intertidal rockweed, Vadas et al. (2004) found significant 

variation in the length of apical tip growth, estimates of standing crop weight, and annual productivity 

estimates. Another study measuring the effects of fucoid bioengineer species on the understory along 

intertidal elevation gradients in Atlantic Canada found “a combined experimental and mensurative 

approach shows that the same bioengineer species affect overall species richness, diversity, and 

composition differently along a stress gradient” (Watt and Scrosati 2013). Specifically, they discovered 

that “bioengineer canopies have different effects on understory communities depending on intertidal 

elevation”, and this is significant to conservation efforts since “the loss of bioengineers is a concern 

because these organisms often have wide-ranging and cascading effects” (Ibid). Therefore, “biologists 

need to consider not only whether bioengineers are present, but also the abundance required to elicit 

positive changes in communities” (Ibid). 

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One review of the ecological impact of harvesting in the northwest Atlantic concluded that “long-term 

harvesting has altered the population structure and population ecology of C. crispus and A. nodosum in 

some areas” but went on to state that “both target species and associated communities are resistant to 

perturbation” (Sharp and Pringle 1990). Foster and Barilotti (1990) emphasize “the need for considering 

the potential effects of seaweed harvesting at both the population and community level, and the utility 

of approaching these effects in a comprehensive manner”. They explain that considering the harvest 

type, procedures, and ecological effects on the target population, community, and ecosystem are 

essential for maintaining harvestable marine macroalgal resources. In an experimental study of the 

ecological effects of harvesting kelp in Chile (in this case for alginates), the researchers concluded there 

were significant impacts on both the harvested and related species: 

Experimental studies of Lessonia nigrescens and L. trabeculata have revealed several ecological 

effects of harvesting that ought to be considered when managing wild stocks of these species. In 

both kelps, the removal of the upper canopy eventually leads to death of the plants. The 

invertebrate fauna does not abandon the holdfast of pruned L. nigrescens. Therefore, both 

partial and complete plant removal has similar mortality 

consequences for the kelp and for the invertebrate fauna associated with the kelp. 

The most important population effects of removal are the increments in inter-plant distances 

and the resulting increasing access of grazers to the kelp holdfast and to inter-holdfast surfaces. 

Increased grazing reduces recruitment of both Lessonia species and modifies the morphology of 

L. trabeculata, rendering individuals of the latter species more susceptible to being removed by 

water movement. (Vasquez and Santelices 1990) 

In a review of global kelp forests, Wernberg et al. (2019) state that “kelp species show global declines 

and, like so many other marine ecosystems, they are under pressure from direct and indirect 

anthropogenic activities”. These include climate change (warming waters, acidification, and increased 

storm activity), fishing (when urchin predators decline due to fishing, urchins increase grazing on kelp), 

and direct harvesting of kelp. However, when species-specific biology is understood and respected, 

sustainable harvests are possible (Ibid). In another global review of kelp forest change, Krumhansl et al. 

(2016) note that “kelp harvesting accounted for recent kelp declines in Central and Northern Chile 

despite a regional cooling trend”. 

Sharp et al. (2006) explain that “harvesting can affect the structure of these marine plant habitats by 

changing branching structure, canopy height, distribution of biomass and overall density of plants and 

fronds”. Vasquez (1995) states that “if the disturbance (e.g. harvest) is strong enough, changes occur in 

the abundance of harvested and/or associated species, and in availability of some resources (e.g. space 

and light)”. 

Boaden and String’s (1980) study abstract in Northern Ireland provides a quantitative overview of 

ecosystem effects of harvesting Ascophyllum nodosum, though it must be noted that the study cut 

rockweed “within 10-15 cm of the base, rather shorter than normal harvesting practice”: 

In 1976 an attempt to establish harvesting in Strangford Lough, Northern Ireland, was opposed 

on mainly theoretical conservation grounds. The attempt began and stopped within a single 

small bay leaving a sharp boundary between cut and uncut areas. A subjective survey apparently 

confirmed the predicted loss of cryptic fauna, decline through predation and the resorting of 

interboulder sediment. In April 1979 the cut and uncut areas were examined in detail to 

determine whether any of these effects had persisted and were demonstrable scientifically. 

Beach and boulder transects and various other studies showed some increases in the cut area. 

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There was significantly more Fucus, Enteromorpha and Ulva; Cirratulus (inhabiting 

Rhodochorton-bound sediment on boulder surfaces) had a greater biomass. Some changes in 

Littorina colour morphs were apparent. Sediment in the cut area was coarser and had 

significantly more crustacean meiofauna. Ascophyllum internodal length and lateral branching 

were increased but it still provided 20 % less shore cover than in the uncut area. There were 

significant decreases in the cover of Cladophora on the sides of boulders and of Halichondria, 

Hymeniacodon and Balanus on undersurfaces. Indeed on the habitable underside of boulders 

total animal cover had been reduced by nearly two-thirds and the average number of species 

per boulder by one-third. It is concluded that Ascophyllum harvesting has a significant and 

persistent effect on shore ecology. Littoral algae are a valuable commercial asset, but it is 

important that some fairly large intertidal areas should be left unharvested for general 

conservation purposes. 

Defining overharvesting is potentially subjective, yet the consequences are not. “Over-harvesting can 

lead to a reduced density of seaweed thalli, skewing the population mix and increasing impurities (i.e. 

other, unwanted seaweed species) in the harvested seaweed loads” (Mac Monagail et al. 2017). “In 

Atlantic Canada, a shift from Irish moss to coralline algae has been observed multiple times over past 

decades due to overharvesting and did not easily or rapidly reverse” (Lotze et al. 2019). Some 

stakeholders have noted a “tragedy of the commons” associated with harvest areas. In Chile, research 

on the effects of fishing pressure found that Territorial User Rights for Fisheries “areas could be 

important ancillary conservation instruments in kelp forest ecosystems, if key processes of the subtidal 

community assemblages (e.g., interactions between grazers and reef fish) are maintained” (Pérez-Matus 

2017). 

An example of differing views on the harvesting Ascophyllum nodosum causing a deficit of detritus and 

the response reiterating the finding can be found in Garbary et al. (2017). The authors affirm that 

harvesting creates a “‘missing’ biomass ... primarily in the form of detritus never produced because of 

the nature and timing of the harvest” and state their original paper underestimated the deficit (Ibid). 

Ugarte and Sharp (2012) assert that the consistent yields of Ascophyllum nodosum is “is proof of good 

management practices and an ecologically sustainable harvest in the Canadian Maritimes”. However, 

Halat et al. (2015)state that while previous research demonstrates the regeneration of Ascophyllum 

nodosum, it “does not address wider ecological issues associated with overall environmental impact”. 

Detrital deficits in Ascophyllum nodosum could be of concern due to “the role of the 'missing' detritus 

that should be serving coastal fertility in the form of dissolved and particulate nutrients for both 

planktonic and benthic organisms from primary producers through to detritivores” (Ibid). “This detritus 

is typically released through epidermal shedding, and if not consumed by herbivores or microbes before 

reaching the upper intertidal zone, it contributes to coastal, terrestrial 

fertility” (Mac Monagail et al. 2017). For kelp, Krumhansl and Scheibling (2012) found that: 

Detritus settles within kelp beds or forests and is exported to neighboring or distant habitats, 

including sandy beaches, rocky intertidal shores, rocky and sedimentary subtidal areas, and the 

deep sea. Exported kelp detritus can provide a significant resource subsidy and enhance 

secondary production in these communities ranging from tens of meters to hundreds of 

kilometers from the source of production. Loss of kelp biomass is occurring worldwide through 

the combined effects of climate change, pollution, fishing, and harvesting of kelp, which can 

depress rates of detrital production and subsidy to adjacent communities, with large-scale 

consequences for productivity. 

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A study measuring the biomass removal of Ascophyllum nodosum found that natural storm occurrences 

removed a significantly higher percentage of holdfast material than commercial harvestings (Ugarte 

2010); however, this point (one made frequently in public comments) must bear in mind that storms are 

a natural part of the ecosystem whereas harvesting and removal of the species from the ecosystem is 

not. As the same paper notes, “environmental concerns will continue influencing marine resource 

management in Canada, especially when the harvested resource is also a habitat” (Ibid). Any amount of 

harvesting will have some ecological impacts, and in Nova Scotia “because Rockweed harvesting disturbs 

habitat through alteration of the canopy structure and has high levels of bycatch, unharvested 

Rockweed beds, which are likely more common on the Eastern Shore, have a substantially higher habitat 

value than those that are harvested” (Jeffery et al. 2020). 

In a three-year study in Norway, the multitrophic effects of kelp harvesting were investigated by 

Lorensten et al. (2010): 

Coastal kelp forest ecosystems provide important habitats for a diverse assemblage of 

invertebrates, fish and marine top-predators such as seabirds and sea mammals. Although kelp 

is harvested industrially on a worldwide scale little is known about the multi-trophic 

consequences of this habitat removal. We investigated how kelp fisheries, which remove 

feeding and nursery grounds of coastal fish, influence local food webs and the availability of 

food to a marine top predator, the great cormorant (Phalacrocorax carbo). We conducted 

experimental harvesting of the canopy-forming kelp (Laminaria hyperborea) during a 3 year 

period (2001–2003) in an area at the coast of Central Norway while synoptically monitoring fish 

occurrence and cormorant foraging parameters. Our results demonstrate that cormorants 

preferentially foraged within kelp-forested areas and performed significantly more dives when 

feeding in harvested versus un-harvested areas suggesting lower foraging yield in the former 

case. In kelp areas that were newly harvested the number of small (<15 cm) gadid fish was 92% 

lower than in un-harvested areas. This effect was persistent for at least 1 year following harvest. 

To our knowledge, this is the first time that the ecological consequences of kelp harvesting have 

been tested at a multi-trophic level. The results presented strongly suggest that kelp harvesting 

affects fish abundance and diminishes coastal seabird foraging efficiency. Kelp fisheries are 

currently managed in order to maximize the net harvest of kelp biomass, and the underlying 

effects on the ecosystems are partly ignored. This study calls for re-assessment of such 

management practices. 

In a twenty-year study of Ascophyllum nodosum in Iceland, Ingólfsson and Hawkins (2008) concluded 

that full canopy recovery after harvest took seven to eight years, but community recovery could take as 

much as twenty years. When Ascophyllum nodosum was removed but understory algae species were 

left undisturbed, some of those species died and did not return to the study sites (Ibid). In the 

southwest English Channel, Migne et al. (2014) found that while “the number of species [and] their 

distribution among trophic groups” was unaffected by canopy removal of Fucus serratus “and the algal 

community was only slightly affected”, the “abundance and biomass of mobile invertebrates ... were 

greatly reduced in the absence of canopy”. 

The importance of harvesting method is underscored in Waage-Nielsen et al. (2003) whose study 

showed that leaving kelp holdfasts was significant to associated kelp fauna. “The remaining holdfasts 

were the best refugia or alternative habitat in this study, as they contained a fauna very similar in 

composition to the fauna associated with the natural kelp plants” (Ibid). Alternative harvesting methods 

for Ecklonia maxima in South Africa, in which only the fronds were cut rather than the whole plant, 

“shows considerable promise in that the required commercial yield can be achieved from much smaller 

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areas than if whole plants are harvested” as plants remain living and recover more quickly (Levitt et al. 

2002). Nevertheless, “the possible effects of disturbance on the benthos, together with the short 

lifespan of suspended kelp zoospores ..., may negatively affect Ecklonia recruitment, particularly if it is 

strongly episodic” (Ibid). In their study of the effects of commercial harvesting of Fucus 

serratus, Palmaria palmata, and Porphyra on ecosystem biodiversity and functioning, Stagnol et al. 

(2016) found that the hand harvesting methods employed had the greatest impact “on the diversity of 

the animal community and the metabolism of the studied area”, largely due to the opportunistic 

settlement of Ulva spp. (2013). Steen at al. examined kelp regrowth after harvesting in Norway and 

found that the target species “had regained its dominance at the harvested sites, however, plant age, 

sizes and epiphytes were still below pre-harvesting levels”. While Laminaria hyperborean biomass 

recovered after four years, this was due to high density of the recovering kelp vegetation; “the density 

of understory kelp recruits 4 years after harvesting was significantly lower than it had been prior to 

harvesting, and this may lead to a slower recovery if future harvests occur before the stocks of 

understory kelp recruits are restored” (Ibid). In their research of the impact of harvesting on canopyforming macroalgae, Stagnol et al. (2016) 

found that patterns of recovery following the harvesting disturbance were variable and matrix 

specific, suggesting that local factors and surrounding habitat characteristics mediated the 

influence of harvesting. The greatest and longest effects of harvesting were observed for the 

targeted species that created a dominant and monospecific canopy on their site prior to the 

disturbance. Another relevant finding was the important natural spatiotemporal variability of 

macrobenthic assemblages associated with canopy-forming species, which raises concern about 

the ability to discriminate the natural variability from the disturbance impact. 

Although certain countries have developed marine macroalgae management plans and regulations, 

others have not (Rebours et al. 2014). As harvesting: 

increases, there is also an urgent need to develop and implement ecosystem-based 

management models and integrated coastal zone planning. Policy makers must develop 

regulations and directives that enable a sustainable exploitation of the natural resource, not 

only to preserve marine and coastal ecosystems but also to ensure social stability and economic 

income of local communities (Ibid). 

Lotze et al. (2019) “outline potential ecosystem-based management approaches that would help sustain 

productive and diverse seaweed-based ecosystems” for harvesting. They specify areas reflected below 

in this proposal, including “maintaining high canopy biomass, recovery potential, habitat structure and 

connectivity, limiting bycatch and discards, while incorporating seasonal closures and harvest-exclusion 

zones into spatial management plans” (Ibid). Stagnol et al. (2016) note their “results support the need 

to implement ecosystem-based management, assessing both the habitat conditions and ecological roles 

of targeted commercial species, in order to insure the sustainability of the resource”. In the case of 

Ascophyllum nodosum, Seeley and Schlesinger (2012) state “besides setting the removal rate at the right 

level, other critical parameters that need to be considered in defining an ecologically sustainable harvest 

include recovery of preharvest rockweed morphology, rockweed bed structure, rockweed community 

structure and function, and ecosystem function”. Similarly, in another study of Ascophyllum nodosum, 

Kay et al. (2015) found that “plant and canopy structure, including length, circumference and density, 

were much better predictors of associated community structure than rockweed biomass, which is often 

used for single-species monitoring”. 

The precautionary approach is not new to marine macroalgae harvesting and was used to development 

a management strategy for in Atlantic Canada following public concern over negative impacts of 

exploitation of marine resources and in recognition of its habitat function for invertebrate and 

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vertebrates (Ugarte and Sharp 2001). Similarly, “the European Union has defined an organic label for 

macroalgae, which implies that the commercial harvest of algae shall not cause a significant impact on 

ecosystems” (Stagnol et al. 2013). In the absence of adequate baseline measures of existing macroalgal 

stands, “robust and precautionary management measures should be adopted” (Lotze et al. 2019). 

Regulatory Oversight 

“The current wild seaweed harvesting methods, regulations and management regimes vary widely 

across species and countries” (Lotze et al. 2019). Government regulatory agencies acknowledge the 

environmental impact of seaweed harvesting through various restrictions. For example, in Nova Scotia, 

the Rock Weed Harvesting Regulations of the Fisheries and Coastal Resources Act describe permitted 

harvest areas, allowable harvesting methods and quotas, leases, and record-keeping. Specifically, the 

“Harvest Manner” specifies harvest cannot interfere with re-growth, cannot harvest “in such a way that 

representative harvest samples contain more than 15% holdfast by weight”, and must leave an upright 

shoot with “an absolute minimum length of 127 mm (5 in.) above the holdfast in non-leased areas” or as 

indicated in the lease management plan (Rock Weed Harvesting Regulations 1996)6

. In Maine, a Fishery 

Management Plan for Rockweed makes recommendations for minimum cutting height, designated noharvest areas, and harvester training (Maine Department of Marine Resources 2014); however, the plan 

has not been enacted to date. Washington Department of Natural Resources is responsible for marine 

macroalgae harvests, where harvest for sale or barter is not allowed on public or private land; in other 

words, the commercial harvesting of macroalgae is prohibited. Rules for hand harvesting, daily per 

person weight limits, and cutting heights are listed. Harvest of kelp and other marine macroalgae are 

regulated by the California Department of Fish and Wildlife and require a license. Regulations designate 

87 kelp beds, some of which are open to all harvesters, some are available for lease, and some are 

closed. Eelgrass and surfgrass are prohibited from harvest. Harvesting is prohibited in state marine 

reserves and state marine parks. Regulations stipulate that harvesters “may not cut attached kelp at a 

depth greater than four feet below the surface of the water at the time of cutting”, and that the kelp 

harvest plan must identify how harvesters will avoid “1. repetitive harvest from individual giant kelp 

plants; 2. harvest of bull kelp from those portions of kelp beds that contain both giant kelp and bull kelp; 

and 3. harvest of giant kelp near sea otter rafting sites used by female sea otters with dependent pups” 

(CDFW 2014). 

In Scotland, “licensing of wild harvesting activities ... provides a means to manage negative 

environmental impacts” (Scottish Government 2016). The absence of accurate assessments of marine 

macroalgae biomass can impede efforts to determine harvest volumes that would have limited 

environmental impact. “To our knowledge, there are no recent estimates of the wild seaweed standing 

stock of the UK nor of the potential stock that could be sustainably harvested” (Capuzzo and McKie 

2016). Similarly, “very little research has been carried out in Northern Ireland on the direct and indirect 

effects of harvesting on biodiversity and coastal processes” (Environment and Heritage Service 2007). 

There is a “lack of specific information on the carrying capacity of marine ecosystems to support 

seaweed harvesting and mariculture” (Ibid). 

6 Some of these provisions, such as minimum cutting height and holdfast content for Ascophyllum nodosum, have 

been noted as potentially inadequate to protect not only regeneration of the target species, but also to mitigate 

ecosystem-wide effects of harvesting. “An overharvest of Ascophyllum could lead to an undesirable level of 

habitat loss at a landscape scale. This is an important perspective which has not been stressed in earlier 

assessments of the Ascophyllum harvest in Nova Scotia.” (Vandermeulen 2013) 

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In Norway, regulations state that “importance shall be attached to the following in the management of 

wild living marine resources and genetic material derived from them: a) a precautionary approach, in 

accordance with international agreements and guidelines, b) an ecosystem approach that takes into 

account habitats and biodiversity, and c) effective control of harvesting and other forms of utilisation of 

resources” among other factors (Marine Resources Act 2008). The Act states in Section 16 The Conduct 

of Harvesting Operations: 

All harvesting and other utilisation of wild living marine resources shall be carried out as in such 

a way as to minimize impact. 

The Ministry may adopt regulations on the conduct of harvesting operations, including 

provisions on the following: 

a) the periods when harvesting is permitted and times for departure from port, 

b) the number of vessels from different vessel groups that may harvest at the same time in an 

area, 

c) prohibition of harvesting in certain areas, of certain species or using certain types of gear, 

d) the design, marking, use and tending of gear and other devices used in connection with 

harvesting, 

e) the maximum or minimum permitted sizes of individual organisms, and requirements for part 

or all of the harvest to consist only of males or females, 

f) permitted bycatches, 

g) the design and use of harvesting gear to reduce damage to species other than the target 

species. ((Directorate of Fisheries 2008) 

It should be repeated that some countries have limited or no regulations on macroalgal harvests, and 

the extent to which countries with regulations have the capacity to fully enforce them is not known. 

The United States has no specific federal regulations on macroalgal harvests. 

A number of third-party standards on sustainable seaweed harvesting offer non-regulatory options for 

verification of environmental stewardship goals, and these were outlined in the board’s previous 

discussion document on this topic. The Aquaculture Stewardship Council-Marine Stewardship Council 

(ASC-MSC) sustainable seaweed standards indicate that there are environmental impacts to harvesting 

seaweed, hence the need for/benefit to certification. Their guiding principles state that “seaweed 

harvesting ... must be conducted in a manner that does not lead to depletion of the exploited wild 

populations”. Harvesting must additionally “allow for the maintenance of the structure, productivity, 

function and diversity of the ecosystem (including habitat and associated dependent and ecologically 

related species) on which the activity depends.” (ASC-MSC 2020) 

It is important to note that the regulations typically focus on regrowth of the harvested species, with 

such conditions as cutting height, holdfast restrictions, or repeat harvest guidelines. While those 

parameters are important, “generally, the management focus is on the regeneration of the seaweed 

resource itself, with no or limited consideration of other species that are associated with the target 

species and may therefore be affected by bycatch or habitat loss and alterations” (Lotze et al. 2019). 

NOSB Fall 2019 Marine Materials Panel 

In order to gain a deeper understanding of the topic from a range of stakeholders, the board convened 

an expert panel in fall 2019 panel to evaluate the environmental impacts of marine macro algae 

harvesting for crop fertility inputs and to explore possible means of mitigating harm. The panel was 

composed of 2 scientists specializing in marine ecology and seaweed, 1 certifier, and 1 harvester. The 

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questions posed to were synthesized from public comment and NOSB members. Panelists were asked 

to identify and focus on those questions that best related to their experience and expertise. 

Questions for the Scientists and a Summary of Their Responses in Italics: 

1. Stakeholders have pointed out the need for a definition for the term “sustain”. Current NOP 

standards for protecting environmental resources rest largely on the terminology of “maintain 

or improve”, while the wild crop standard uses the word “sustain”. The NOP regulations do not 

define this term. §205.200 requires that crop producers “maintain or improve the natural 

resources of the operation”. §205.207(b) requires that wild crops be “harvested in a manner 

that ensures that such harvesting or gathering will not be destructive to the environment and 

will sustain the growth and production of the wild crop”. How can the NOP define, measure, 

and verify the phrases “not destructive to the environment” and “sustain the growth and 

production” as related to wild harvested marine macroalgae? 

a. Biomass is indicative of abundance of dependent organisms and measurable; 

architecture is more challenging to assess, but could be done intermittently. 

2. Could practice standards or guidelines be created that are sufficiently broad to cover the wide 

geographic distribution and differences in marine ecosystems while being simultaneously 

specific enough to provide adequate protection of marine algae and the ecosystem functions 

they afford? 

a. Conservative guild level guidelines, but may require species specificity. 

3. What are the environmental implications of taking no action? 

a. Given the rate of ocean change, the paucity of data on many of these systems, and 

tendency for overexploitation of marine resources, a cautionary approach is warranted. 

Additionally, aquaculture is an alternative to meet demand. 

4. Define an efficient, science-based method for measuring existing biomass to establish a 

baseline. How would this be measured post-harvest? Is there existing data from established 

harvest regions? 

a. We reviewed several developing remote sensing and genetic techniques, in addition to 

standard visual assessments. Validation and training required. 

5. For all algae, what are the best methods for harvesting that minimize the impact on the 

recovery of the population of the harvested species and maintain ecosystem function and 

services? What would be measured and what benchmarks would be set? Who should 

determine the methods/benchmarks? 

a. Benchmarking of harvesting approaches (e.g., holdfast minimums, no trawling). 

6. Are there some species that are so important to ecosystem structure and function that harvest 

should not be permitted at all? 

a. Coralline algae should be considered as off-limits to harvesting because of their life 

history characteristics and ecological importance. 

7. Should there be protected areas that are off limits to harvesting? Should seasonal restrictions 

be considered? 

a. Yes and Yes! 

8. What is an acceptable level of bycatch? Should this be assessed on a species by species basis? 

Are there any bycatch species that could prevent harvesting in an area altogether? 

a. Harvest using least destructive and most selective gear; implement bycatch monitoring. 

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Questions for the Certifier and Harvester: 

1. What methods are currently being used by certifiers and harvesters to verify environmental 

goals and avoidance of harm when certifying marine algae to the wild crop standard for 

livestock feed, human consumption, or as a crop input? 

2. Are certifiers adequately trained to certify marine algae? What could be done to address any 

deficiencies in knowledge and training? 

3. What concerns exist regarding the NOP’s regulatory authority to require organic certification of 

a crop production input ingredient? 

4. Are government regulatory structures in place to ensure habitat protection from overharvesting of marine algae? Should marine algae harvesting be permitted (under the organic 

regulations) where those regulations are weak or non-existent? 

5. If biomass assessments are made pre- and post-harvest, who should perform them? 

6. Who would monitor compliance and enforce management standards? 

7. Should the NOSB propose requiring organic certification of marine macro algae crop input 

ingredients, create an annotation, or explore other methods to ensure that environmental 

criteria are met? 

The expert panel provided the board with much-needed information on harvesting methods, 

certification concerns and areas for standards, the biology and ecology of marine macroalgae, and 

recommendations on future work. The harvester testified about his company’s many years of research 

on harvesting impacts and management plans enacted to minimize them. Annual surveys are 

conducted to establish proper harvest quotas. The certifiers addressed current certification of “kelp” as 

an agricultural product in organic livestock feed and emphasized that additional training for certifiers is 

needed, as was proposed in NOP 5027-1. They certify six operations to the wild crop standard for “kelp” 

harvesting. 

The scientists testified that marine macroalgae are ecosystem engineers providing habitat to other 

species, that harvesting reduces biomass and structure, and the extent of impact depends on harvesting 

methods. In some cases, seaweeds can recover. When clear-cut, it can take decades for recovery. They 

suggested a balanced view of desired ecosystem services from marine macroalgae. They affirmed that it 

was possible to create generalizable harvest parameters that could include baseline biomass 

assessments, minimum cutting heights and holdfast removal, and prohibitions on trawling. 

Proposal: 

Through its previous discussion documents, the board variously explored either requiring organic 

certification of macroalgae ingredients as a means of monitoring the environmental impact of harvests 

or an annotation in the National List that would achieve a similar result. There is resistance among 

some stakeholders to requiring organic certification due to concerns about a slippery slope for other 

natural inputs. On the other hand, there are species that are currently being certified organic for human 

consumption or livestock feed that are also used for crop fertility inputs. Additionally, there has been 

concern that requiring organic certification without specifying additional harvest parameters could lead 

to excessive variation in interpretation of the wild crop standard between certifiers. 

Some were apprehensive that verification could increase the cost of these inputs for farmers. Public 

testimony by one certifier noted that of the 19 crop inputs they approve containing aquatic plant 

extracts, 7 already contain certified organic plant extracts. A quick search for certified organic kelp meal 

revealed a number of products containing certified organic Ascophyllum nodosum. When compared 

with kelp meal products containing the same species that was not certified organic, there were 

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instances in which the product containing certified organic Ascophyllum nodosum was cheaper than the 

product containing Ascophyllum nodosum that was not certified organic. 

After significant consideration, it was decided that an annotation with specific wording about harvest 

procedures was a desirable and achievable goal. In consultation with the NOP, it was determined that 

language requiring verification within the annotation itself was not feasible; however, that does not 

diminish the requirement to follow the annotation. 

Although not a condition of the annotation, some harvesters and/or processor may seek verification. 

This could be done in a number of ways, including through a “material evaluation program” similar to 

the material evaluation requirement for High-Nitrogen Liquid Fertilizers (HNLF) explained in NOP 

Guidance 5012. A sample fee schedule for a material evaluation program can be viewed at the Organic 

Materials Review Institute and varies according annual gross sales for the company, the type of product 

being reviewed, and additional situations. Verification could also potentially be achieved through 

organic certification, with the certifier inspecting to the annotation harvest parameters as well as the 

wild crop standard. 

This annotation applies only to the raw marine macroalgal ingredient, not the resulting product. 

Companies harvesting the marine macroalgae would be responsible for harvesting according to the 

annotation parameters. Moreover, if the harvester chose to certify their macroalgae harvest, the 

ingredient list could state that the marine macroalgae ingredient was certified organic, i.e. “USDA 

Organic Ascophyllum nodosum”. If a producer opted to undergo a material evaluation program, the 

macroalgae would be product-verified and listed by that material review organization (producers can be 

individual harvesters or companies hiring independent contract harvesters). 

While there would be some increased cost for producers who decided to certify their macroalgae or 

have it reviewed through a material evaluation program, this is not dissimilar to the cost farmers and 

handlers bear when electing organic certification for their products. Moreover, a number of harvesters 

are already certifying all or part of their macroalgal harvests. There may be uncertified harvesters 

already harvesting to the annotation parameters for whom acquiring verification would not necessitate 

significant changes to their practices. 

This is a complicated subject and one the board has worked on for over five years. Differing views on 

the need for action exist. Finding the correct means of addressing harvesting has involved important 

exchanges between the board and stakeholders. The annotation must be broad enough to cover the 

range of species, geographies, and harvest methods while simultaneously being specific enough to be 

useful and feasible. 

The Materials Subcommittee is proposing an annotation to the organic regulations stipulating harvesting 

parameters for marine macroalgae used in crop fertilizers, providing a science-based process and 

parameters to ensure that harvesting limits harm to the environment. The annotation wording came 

about through review of previous public comments, in looking at the Marine Materials Fall 2019 panel’s 

scientists’ recommendations, and in conversations with Dr. Robin Hadlock Seeley (Shoals Marine 

Laboratory, Faculty, University of New Hampshire and Cornell University). The draft annotation was 

then sent to the two scientist seats on the panel –Dr. Allison Schmidt (Dalhousie University, Professor, 

Department of Biology) and Dr. Nichole Price (Bigelow Laboratory for Ocean Sciences, Senior Research 

Scientist)—and they collaborated to make additional edits. 

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The draft language was shared with the certifier on the panel, Chris Grigsby (MOFGA Certification 

Services, Director) and the harvester, Dr. Raul Ugarte (Acadian Seaplants, Senior Manager Resource 

Science). Comments said the annotation should include not only biomass and architecture, but also the 

other species in the community. Additionally, it was suggested that a more feasible and ecologically 

sound metric than biomass and architecture returning to pre-harvest levels might instead be harvest 

rates below the annual rates of regeneration. 

The annotation language was next reviewed, and edits were suggested, by Dr. Michael Graham at Moss 

Landing Marine Laboratories and Co-/Managing-Editor, Journal of Phycology. The draft annotation 

language was subsequently sent to 18 different marine scientists across the US, Canada, and Chile to 

solicit their feedback on feasibility, adequacy, and suggested edits. They came via public and 

stakeholder comments and recommendations and through referrals from scientists contacted about last 

fall's expert panel. Those that replied were: 

• Dr. Susan Brawley, University of Maine, Professor School of Marine Sciences 

• Dr. Dan Reed, University of California Santa Barbara, Marine Science Institute 

• Dr. Robert DeWreede, University of British Colombia, Professor Emeritus Botany 

• Dr. Thomas Mumford, Marine Agronomics LLC, Retired from the Washington Department of 

Natural Resources 

• Dr. Heike Lotze, Dalhousie University, Professor Department of Biology 

• Dr. David Garbary, St. Francis Xavier University, Professor of Biology 

• A colleague of Dr. Pam Krone, Monterey Bay National Marine Sanctuary 

• Dr. Jennifer Smith, University of California at San Diego Scripps Institution of Oceanography, 

Professor of Marine Biology 

• Dr. Brian Beal, University of Maine, Professor of Marine Ecology & Director of the Marine 

Science Field Station 

• Dr. Alejandro Heriberto Buschmann Rubio, Universidad de los Lagos, Professor 

• Glyn Sharp, Retired from Department of Fisheries and Oceans-Nova Scotia 

Broadly speaking, there was general agreement about the annotation and suggestions for revisions 

(with the exception of one scientist who thought it was satisfactory and feasible as written and one who 

expressed concern that it was too broad to be effectively applied to specific regions or species). Edits 

were made to the proposed language based careful analysis of the feedback received from the various 

scientists, including Drs. Schmidt, Price, and Ugarte from the Fall 2019 Expert Panel. 

The “prohibited harvest areas” section was amended to specify established public and private 

conservation areas and to include sanctuaries and preserves. “Trawling” was refined based on near 

universal feedback to “bottom trawling”. Given a range of views on language referring to “reproductive 

individuals”, the wording was changed to reflect the diversity of species and their reproductive 

characteristics by rohibiting practices that prevent reproduction of the population. Additional language 

was added based on suggested wording from Dr. Ugarte regarding sufficient propagules to maintain the 

population. Phrasing about maintaining ecosystem functions was also added. Original wording stating 

that bycatch should be “minimized” was recognized as subjective, and so the wording was changed to 

“prevented” and “eliminated” in the case of special status species. One scientist noted that the absence 

of bycatch can demonstrate an unhealthy marine community. Monitoring practices would need to be 

clarified in guidance. 

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The language that drew the greatest amount of feedback was that regarding biomass and architecture 

returning to pre-harvest levels prior to repeat harvesting. Questions arose about how to measure this. 

Monitoring and data collection to measure biomass and architecture can take place using a variety of 

methods, including remote sensing, drones, GIS maps, genetic techniques, transect sampling, and visual 

assessments. Guidance would be needed to clarify how and when sampling should occur. It was 

recommended that “height” should be an average with some variation. One scientist noted that 

commercial harvesting affects the architecture of some species, making it challenging to require a 

complete return to pre-harvest levels. It was suggested that guidance on how different types of species 

are harvested would be needed. Establishing fully accurate pre-harvest levels was deemed difficult. 

One commenter said that hand raking of some species is preferred over mechanical harvest as it reduces 

in incidence of cutting to minimum allowed heights, which can negatively impact the biological 

community. An initial limited test harvest was recommended, along with subsequent designated strip 

harvesting. It is not the intent of the language to stop harvesting to establish a baseline measurement. 

All of these are points that should be evaluated in guidance. 

The second version of the annotation with incorporated comments was sent back to all those who 

originally provided feedback. This time there was more agreement from the scientists that the changes 

had improved the annotation. Roughly half felt it was adequate as edited. A few had suggestions for 

additional edits. Thus, a third version of the language was drafted based on feedback and in 

consultation with four of the scientists, paying close attention to improvements that could gain the 

broadest degree of consensus within the stakeholder community. Importantly, the scientists represent 

a range of specialties in marine macroalgae. It was noted that storms and natural succession can impact 

biomass and architecture. Ice scouring of rock ledges and storm events affect biomass and architecture 

in the case of Ascophyllum nodosum. The earlier annotation language specified a return to pre-harvest 

levels. Preharvest measures of biomass and architecture in ice-scoured or winter storm-impacted areas 

may not adequately form the basis of sufficient recovery. Consequently, the wording was further 

developed to clarify that repeat harvest cannot reoccur until the biomass and architecture approach 

that of undisturbed natural stands of the target species in that area. This recognizes variability in site 

specific conditions. 

All of the scientists were sent the final annotation wording. The vast majority agreed with the final 

wording as it was written, as well as the process of developing the language. Three provided additional 

comments, and most of those were incorporated into the final language. The two outstanding issues 

raised that will need to be explored in guidance are how to measure architecture (though length and 

circumference can be measured in a quadrant for intertidal species, this is more challenging for subtidal 

species; whether estimated measurements are adequate and how to define this should also be 

considered), and the importance of the relationship between species size and age. The final annotation 

wording reflects of a diverse spectrum of scientific feedback, collaboration, and support. The 

subcommittee thanks all those who participated in its crafting, particularly Dr. Allison Schmidt and Dr. 

Nichole Price for their tremendous time, effort, and expertise in helping guide this language 

development. 

Adoption of this annotation should be accompanied by a NOP-appointed scientific task force to 

elaborate additional guidance and instruction to certifiers, with particular focus on providing speciesspecific parameters7

. The task force could identify the top three to five species used and provide 

7 Modifying existing third-party standards that address environmental impact of seaweed harvesting or using them 

as a reference point could be explored by the task force. 

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recommendations for their unique biological and geographical characteristics. A periodically updated 

living document, reviewed at sunset intervals, would serve to address changes to the annotation as 

needed and to promote consistency in interpretation and application. Adoption of this annotation 

should be followed by a lengthy phase-in period of five years to allow for industry adaptation. Material 

review organizations and certifiers would need to use staff qualified to evaluate the harvest against the 

annotation parameters, for harvesters seeking certification or product verification. Task force-driven 

guidance should detail needed areas for training. 

These parameters reflect values and science around marine macroalgae harvest the board supports. 1) 

Protected conservation areas should not be used for harvest of organic fertility inputs. 2) Bottom 

trawling is prohibited because of its potential for damage to the surrounding ecosystem, thus preventing 

the harvest of most coralline algae (as recommended by the scientists on the Fall 2019 Expert Panel) 

because of its slow growth rate8

. 3) Harvesting should not interfere with reproduction for the continued 

growth and ecosystem functions of the species. 4) Although harvesting affects the architecture of some 

species, biomass or percent cover and architecture (density and height) must be allowed to approach 

the biomass and architecture of undisturbed natural stands of the targeted species in that area before a 

subsequent harvest so that ecosystem function interruption is minimized, to the extent possible. 5) 

Prevention and monitoring of bycatch are important to avoiding unnecessary mortalities associated with 

the harvest. 

It is not intended that every harvest be monitored as that would be impossible to oversee, just as 

organic inspectors are not present for every action taken during a farm’s growing season. As with the 

entire organic label, trust is involved. Finally, harvesters must comply with all local, state, federal, and 

tribal regulations, permits, and jurisdictions. 

§205.601 Synthetic substances allowed for use in organic crop production 

1) This proposal suggests an annotation to §205.601 (j)(1) requiring (proposed annotation changes are in 

red): 

In accordance with restrictions specified in this section, the following synthetic substances may be used 

in organic crop production: Provided that, use of such substances does not contribute to contamination 

of crops, soil, or water... 

(j) As plant or soil amendments. 

(1) Aquatic plant extracts (other than hydrolyzed) –Extraction process is limited to the use of potassium 

hydroxide or sodium hydroxide; solvent amount use is limited to that amount necessary for extraction. 

Harvest Parameters - “Prohibited harvest areas: established conservation areas under federal, state, or 

local ownership, public or private, including parks, preserves, sanctuaries, refuges, or areas identified as 

important or high value habitats at the state or federal level. Prohibited harvest methods: bottom 

trawling and harvest practices that prevent reproduction and diminish the regeneration of natural 

populations. Harvest practices should ensure that sufficient propagules9

, holdfasts, and reproductive 

8 In the Mediterranean, Barbera et al. (2003) note “that maerl beds are non-renewable resources and cannot 

sustain direct exploitation”, a species and region cited in the 2016 TR as used in organic fertilizers. Lotze et al. 

(2019) state “Trawling and dredging generally entrain a wide range of non-target species and have the most 

damaging effects on seafloor habitats, including the seaweed canopy”. 

9 Definition of a propagule: a vegetative structure that can become detached from a plant and give rise to a new 

plant, e.g. a bud, sucker, or spore. 

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structures are available to maintain the abundance and size structure of the population and its 

ecosystem functions. Harvest timing: repeat harvest is prohibited until biomass and architecture 

(density and height) of the targeted species approaches the biomass and architecture of undisturbed 

natural stands of the targeted species in that area. Bycatch: must be monitored and prevented, or 

eliminated in the case of special status species protected by U.S. Fish and Wildlife Service or National 

Marine Fisheries Service." 

2) An additional listing is proposed at §205.602 prohibiting marine macroalgae unless produced in 

accordance with the following annotation (identical to that proposed for §205.601 (j)(1)) in order to 

address marine macroalgae used in non-synthetic products and therefore not covered by the annotation 

under Aquatic Plant Extracts. This prohibition, unless harvested in accordance with the annotation, 

would help safeguard that marine macroalgae harvested for and used in organic crop production do not 

harm the environment (proposed changes are in red): 

§205.602 Nonsynthetic substances prohibited for use in organic crop production. 

The following nonsynthetic substances may not be used in organic crop production: 

(j) Marine macroalgae (seaweed)--unless harvested in accordance to the following parameters: 

Non-commercial harvests for whole and unprocessed seaweed are exempt from these parameters. 

Harvest Parameters - “Prohibited harvest areas: established conservation areas under federal, state, or 

local ownership, public or private, including parks, preserves, sanctuaries, refuges, or areas identified as 

important or high value habitats at the state or federal level. Prohibited harvest methods: bottom 

trawling and harvest practices that prevent reproduction and diminish the regeneration of natural 

populations. Harvest practices should ensure that sufficient propagules10, holdfasts, and reproductive 

structures are available to maintain the abundance and size structure of the population and its 

ecosystem functions. Harvest timing: repeat harvest is prohibited until biomass and architecture 

(density and height) of the targeted species approaches the biomass and architecture of undisturbed 

natural stands of the targeted species in that area. Bycatch: must be monitored and prevented, or 

eliminated in the case of special status species protected by U.S. Fish and Wildlife Service or National 

Marine Fisheries Service." 

Public comment indicated some farmers in coastal regions harvest small amounts of marine macroalgae 

for on-farm, non-commercial use. Such harvests are exempt from this annotation. 

Conclusion: 

On issues where universal agreement does not exist, it is the board’s aim to pursue a middle ground 

approach where achievable. Given the strong calls for action on the one hand and statements that 

action is unnecessary on the other, this proposal reflects the best effort at compromise. Prohibition of 

the use of marine macroalgae in crop fertility inputs is not viable, nor is inaction on safeguarding marine 

ecosystems from the impacts of harvesting. This annotation does not prohibit marine macroalgae but 

provides scientifically sourced harvest parameters to protect the target species and its associated 

community. 

Much of organic agriculture is based on the precautionary principle. Similarly, this proposal prevents 

possible negative environmental impacts from commercial harvesting of marine macroalgae. The 

potential for a negative impact is sufficient to warrant a cautionary approach and was recommended by 

10 Definition of a propagule: a vegetative structure that can become detached from a plant and give rise to a new 

plant, e.g. a bud, sucker, or spore. 

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the scientists on the Fall 2019 Expert Panel. This proposal furthers the commitment to continuous 

improvement in organic farming by valuing marine macroalgae not simply as resources but also as 

integral species within complex ecosystems. 

In the presence of conflicting views and given evidence describing the environmental impacts of 

harvesting, this proposal seeks to ensure that the raw input ingredient, marine macroalgae used in crop 

fertility inputs, is not harmful to the environment by establishing harvest parameters created in 

collaboration with marine science experts in the field. The review of the literature demonstrates the 

possibility for multi-level environmental effects of harvesting marine macroalgae. Even where 

regulations exist, and they are not legislated in every country, they do not typically address effects on 

the community and ecosystem functions and instead focus on regrowth and recovery of the targeted 

species. The organic regulations, as noted in the earlier section on relevant areas of the rule, is 

concerned not only with single species impacts but also with ecological balance and biodiversity 

conservation. This proposal helps assure that marine macroalgae used in organic production is 

consistent with a system of sustainable agriculture. 

Subcommittee Vote: 

Motion to adopt the proposal on Marine Macroalgae in Crop Fertility Inputs 

Motion by: Emily Oakley 

Seconded by: Dave Mortensen 

Yes: 5 No: 0 Abstain: 0 Recuse: 0 Absent: 1 

Approved by Dave Mortensen, Subcommittee Chair to transmit to NOSB, August 11, 2020 

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