Notitie: potentiële effecten van duurzame zeewierproductie op de biodiversiteit in de Noordzee : ecosysteem diensten en/of ecologische effecten

Development of Offshore Seaweed Cultivation : food safety, cultivation, ecology and economy : synthesis report 2018

“…in water framework directives. A factsheet was published , Tonk & Jansen 2018a) describing positive and negative effects of seaweed aquaculture on biodiversity based on a literature study. In this study it was taken into consideration that offshore seaweed cultivation will be developed in combination with wind farms, and therefore cumulative effects were evaluated.…”

Processing-mediated reduction of elemental contaminants in seaweed food and feed products : Processing-mediated reduction of contaminant levels in seaweed products

“…Moreover, (offshore) seaweed cultivation can promote healthy ecosystems by taking up nutrients (and thereby reduce the eutrophication levels in e.g. the North Sea), by providing habitat for invertebrates and young fish (thereby increasing biodiversity) and by oxygenating water and increasing the pH (thereby counteracting acidification), although intensive farming can also have negative ecological impacts due to strong nutrient competition, increased traffic and risk to animals and traffic formed by the seaweed cultivation installations themselves (Tonk & Jansen, 2019). Protein content varies widely across seaweed species and ranges from 0.7 to 45% of its dry weight, with red seaweeds showing the highest protein contents (Banach, van der Berg, et al, 2022;Cherry et al, 2019).…”

Development of a framework and toolbox for measuring and evaluating ecosystem interactions of seaweed aquaculture

“…Floating structures in the open sea are known to attract both pelagic and demersal fish (Kingsford, 1993, Morrisey et al, 2006. Numbers of fish attracted by seaweed production are still lacking (Tonk and Jansen, 2019). However, a positive correlation is demonstrated between seaweed production and the amount of herbivorous fish caught in Southeast Asian countries (Hehre and Meeuwig, 2016).…”

“…In addition seals can use artificial structures such as lines and buoys as a resting place. Studies directly related to seaweed farms are not known (Tonk and Jansen, 2019), but it is plausible that mammals are attracted by the high numbers of prey in seaweed farms, similar to sea otters in kelp forests (Estes and Duggins, 1995) or seals that systematically forage around offshore wind farms (Russell et al, 2014). The effect of additional shipping/harvesting activities on marine mammals should also be considered.…”

“…For instance, growing seaweeds take up nutrients from the surrounding environment. While this may be beneficial in nutrient-enriched areas, it can lead to competition for nutrients with wild local seaweed communities, seagrass or microalgae when nutrients are scarce (Tonk and Jansen, 2019).…”