Species Use Database

Rockweed
Ascophyllum nodosum

Used for Fertilizer, Soil amendment in New Brunswick, Nova Scotia and Maine

A. Species

Scientific name: Ascophyllum nodosum

Common name(s): Rockweed

Global IUCN Red List Threat Status:


B. Location of use

Geographic location(s):

  • New Brunswick
  • Nova Scotia
  • Maine

Country/Region: US/Maine + Canada/Maritimes


C. Scale of assessment

Scale of assessment: Regional/Continental/Multi-country level

Name/Details of location: Cosatal areas of Maine, Nova Scotia and New Brunswick


D. Timescale of use

Start Year: 1984

End Year: 2010


E. Information about the use

How is the wild species sourced?: Wild species sourced from its natural habitat

Type of use: Extractive

Practice of use: Targeted fishing harvesting/exploiting or collecting wild aquatic resources

Lethal or non-lethal: Non-Lethal

Does this use involve take/extraction of: Only parts or products of the organism

Purpose(s) of end use: Fertilizer, Soil amendment

Motivation of use: Income generation from trade (individual/household/community) and Largescale commercial exploitation for trade

Is this use legal or illegal?: Legal under national law


F. Information about the Users

Which stakeholder(s) does the record primarily focus on?: Local people and National external


G. Information about the sustainability of use

Is there evidence that the use is having an impact on the target species?: Wild species sourced from its natural habitat

Has an assessment (or judgement) of sustainability of the use of the target species from an ecological perspective been recorded?: Yes, considered sustainable

Details of assessment carried out: Data from the various State and Province Departments responsible for regulation.

Brief summary on why the use has been assessed/judged to be sustainable or unsustainable: Historically, rates of harvest were highly exploitative and entirely unsustainable, and so, over the course of this study's records Sate and Provincial regulators have worked to bring the rockweed harvesting industry to a condition of sustainability. From a monitoring study in the Cobscook Bay Rockweed Management Area (ME), it was found that around 17% of available biomass in each bay sector can be removed each year, and this has become the benchmark for sustainability (although it might not be entirely generalizable, according to this study. Nevertheless, this study disputes the overall veracity of this ecological sustainability. I have recorded use here as sustainable (the management intention) because recording it as not determined falsely implies no one tried, and they did - also it precludes an assessment box from being available.

Has an assessment (or judgement) of sustainability of the use of the target species from an economic perspective been recorded?: Yes, considered sustainable

Details of assessment carried out: this study

Brief summary on why the use has been assessed/judged to be sustainable or unsustainable: Current management has the explicit intent of attempting to ensure current levels of use are socio-economically sustainable, based on achieving ecological sustainability; however, in the 80s-90s harvest was not sustainable and this study expresses concern on whether current maximum sustainable yield (MSY) quotas are appropriate.. For example, pilot harvest was starting in the island community of Grand Manan (NB) in 1995, and the Grand Manan Fisherman’s Association, Chamber of Commerce, Municipal Council, and representatives of traditional dulse and periwinkle harvesters formed the Island Rockweed Committee to protect Grand Manan’s rockweed, asserting that “rockweed was as essential to their fisheries as topsoil is to farmers. The citizens of Grand Manan viewed the rockweed cutting as a threat to their economic sustainability.97As a result of conservation concerns, a strict set of regulations was enacted in New Brunswick, including a cap on landings (originally 10,000 mt, but after industry reassessed total biomass, the cap was raised to 11,800 mt).

Has an assessment (or judgement) of sustainability of the use of the target species from a social perspective been recorded?: Yes, considered sustainable

Details of assessment carried out: this study

Brief summary on why the use has been assessed/judged to be sustainable or unsustainable: Current management has the explicit intent of attempting to ensure current levels of use are socio-economically sustainable, based on achieving ecological sustainability; however, in the 80s-90s harvest was not sustainable and this study expresses concern on whether current maximum sustainable yield (MSY) quotas are appropriate.. For example, pilot harvest was starting in the island community of Grand Manan (NB) in 1995, and the Grand Manan Fisherman’s Association, Chamber of Commerce, Municipal Council, and representatives of traditional dulse and periwinkle harvesters formed the Island Rockweed Committee to protect Grand Manan’s rockweed, asserting that “rockweed was as essential to their fisheries as topsoil is to farmers. The citizens of Grand Manan viewed the rockweed cutting as a threat to their economic sustainability.97As a result of conservation concerns, a strict set of regulations was enacted in New Brunswick, including a cap on landings (originally 10,000 mt, but after industry reassessed total biomass, the cap was raised to 11,800 mt).

Has an assessment (or judgement) of sustainability of the use of the target species from a human health perspective been recorded?: not recorded

Has an assessment (or judgement) of sustainability of the use of the target species from an animal health/welfare perspective been recorded?: not recorded


Recommendations provided in the record to maintain or enhance the sustainability of the use of the target species

This study concludes that he current metric for “sustainable” harvests—MSY—is inappropriately narrow. A metric for an ecologically sustainable harvest must be based on the data from large-scale, long-term studies of postharvest recovery of rockweed morphology, of rockweed community structure and function, and of ecosystem impacts. Until this metric is developed and enforceable regulations based on it are developed, commercial-scale rockweed cutting should not be permitted.


Record source

Information about the record source: scientific_pub

Date of publication/issue/production: 2012-01-01T00:00:00+0000

Source Reference(s):

Seeley, R. H., & Schlesinger, W. H. (2012). Sustainable seaweed cutting? The rockweed (Ascophyllum nodosum) industry of Maine and the Maritime Provinces. Annals of the New York Academy of Sciences, 1249(1), 84-103.

Date of record entry: 2022-12-28