Modify harvest methods of macroalgae
Overall effectiveness category No evidence found (no assessment)
Number of studies: 0
Background information and definitions
The commercial harvest of macroalgae (e.g. kelp) can impact subtidal benthic invertebrates through removal of the plant itself, direct physical damage and removal of invertebrates, or through disturbance to the seabed (Pirker 2002; Stagnol et al. 2016). The harvest method can be modified in an attempt to prevent such negative impacts. For instance, harvesting macroalgal blades rather than mechanically removing the whole plant can reduce disturbances to the seabed and retain some benefit of macroalgal canopy (Levitt et al. 2002). Increasing the time between consecutive harvests can also potentially help reduce the pressure and allow for natural recovery. Similarly, harvesting patches of macroalgae rather than entire areas can potentially allow natural recolonization of subtidal benthic invertebrates from nearby unharvested patches.
Levitt G.J., Anderson R.J., Boothroyd C.J.T. & Kemp F.A. (2002) The effects of kelp harvesting on its regrowth and the understorey benthic community at Danger Point, South Africa, and a new method of harvesting kelp fronds. South African Journal of Marine Science, 24, 71–85.
Pirker J.G. (2002) Demography, biomass production and effects of harvesting giant kelp Macrocystis pyrifera (Linnaeus) in Southern New Zealand.
Stagnol D., Michel R. & Davoult D. (2016) Unravelling the impact of harvesting pressure on canopy-forming macroalgae. Marine and Freshwater Research, 67, 153–161.