Sea-weeding Resources

This page provides resources that can help you decide whether sea-weeding is right for your context and, if it is, how to set up a sea-weeding study. Because every reef and every seaweed species is different, we do not offer any prescriptive advice on this website. Instead, we’ve tried to make resources easily accessible so that you can learn more about existing research projects and restoration efforts.

Please reach out to us if you’d like to discuss your particular context or to share your own sea-weeding story with the network.

Sea-weeding Practitioner Guidelines

Earthwatch Australia recently published these guidelines to setting up a new sea-weeding site. While the guidelines are written for the Great Barrier Reef context, a lot of the information can be adapted to other sites.

More community guidelines are coming soon . . .

Sea-weeding in the News

Read about sea-weeding in The Conversation.

Sea-weeding Research

This table summarises research studies on the removal of macroalgae from coral reef sites across the world. We will be updating this table as new research is released. Please reach out to us if you know of a study that should be included here. The original articles can be found by clicking on the author names in Column 1.

Study Location Duration Scale (including control plots / areas) Repeat removals? Algal species Native or invasive algal species Study scope
Schmitt et al. (2022) Mo’orea, French Polynesia 5 years 45 coral outcrops, 1–3 m² surface area each Yes, twice in 5 years Turbinaria ornata Native Algal density and cover, herbivory effects on algal regrowth, coral recruitment
Smith et al. (2022) Magnetic Island, Australia 1.5 years 24 plots, 25 m² each Yes, 2–3 times yearly Sargassum spp. Native Coral recruitment
Schmitt et al. (2019) Mo’orea, French Polynesia 3 years 15 coral outcrops per treatment, 1–4 m² surface area each No Turbinaria ornata Native Algal abundance, herbivory rates required to maintain low algal biomass
Neilson et al. (2018) Hawai’i, USA 2 years 4 patch reefs, total ~42,000 m² No Eucheuma and Kappaphycus. Gracilaria salicornia and Acanthophora spicifera were not directly targeted for manual removal. Invasive Benthic cover
Bulleri et al. (2018) Mo’orea, French Polynesia 8 months 15 coral outcrops, 2–3 m diameter No Turbinaria ornata Native Coral recruitment, bacterial assemblages
Loffler and Hoey (2018) Orpheus Island, Australia 1 year 24 plots, 2.25 m² each No Sargassum spp. (predominantly Sargassum polycystum, S. fissifolium, and S. oligocystum) Native Density and height of algae regrowth
Kittinger et al. (2016) Hawai’i, USA 1 year 11 hectares No, but progressive over 15 months Leather mudweed (Avrainvillea amadelpha) Invasive To restore native algae and seagrass (not necessarily coral)
McClanahan et al. (2011) Glover’s Reef, Belize 1 year 16 patch reefs of 25–50 m² each Yes, monthly Brown algae (Turbinaria, Sargassum, Lobophora, and Padina). Also, less abundant red and green algae. Native Survival, health, and growth of transplanted corals; fish populations
Conklin and Smith (2005) Hawai’i, USA 1 year 24 plots, 0.25 m² each No Kappaphycus spp. Invasive Algal regrowth rates
McClanahan et al. (2002) Watamu Marine National Park, Kenya 1 year 8 plots, 100 m² each No Dominant: Sargassum duplicatum and Halimeda opuntia. Other species of Sargassum and Halimeda were found, as well as species in the genera Turbinaria, Dictyota, Lobophora, Hypnea, and Amansia. Native Benthic cover, fish populations
McClanahan et al. (2001) Glover’s Reef, Belize 1 year 8 patch reefs, approx. 1,000 m² each No Brown algae (Turbinaria, Sargassum, Lobophora). Also, less common brown, red, and green algae. A list of specific species was identified in Appendix I. Native Benthic cover, fish populations
McClanahan et al. (1999) Watamu Marine National Park, Kenya 3 months 8 plots, 100 m² each No Dominant: Sargassum duplicatum and Halimeda opuntia. Other species of Sargassum and Halimeda were found, as well as species in the genera Turbinaria, Dictyota, Lobophora, Hypnea, and Neurymenia. Native Benthic cover, fish populations
Tanner (1995) Heron Island, Australia 2 years 99 outcrops, 0.5–1.5 m² each Yes, every 6–8 weeks Peyssonnelia spp., Turbinaria ornata, Chlorodesmis fastigiata, and Halimeda spp. Native Benthic cover, coral growth, fecundity