Maeve D. Edwards

Prospects and challenges for industrial production of seaweed bioactives

Large‐scale seaweed cultivation has been instrumental in globalizing the seaweed industry since the 1950s. The domestication of seaweed cultivars (begun in the 1940s) ended the reliance on natural cycles of raw material availability for some species, with efforts driven by consumer demands that far exceeded the available supplies. Currently, seaweed cultivation is unrivaled in mariculture with 94% of annual seaweed biomass utilized globally being derived from cultivated sources. In the last decade, research has confirmed seaweeds as rich sources of potentially valuable, health‐promoting compounds. Most existing seaweed cultivars and current cultivation techniques have been developed for producing commoditized biomass, and may not necessarily be optimized for the production of valuable bioactive compounds. The future of the seaweed industry will include the development of high value markets for functional foods, cosmeceuticals, nutraceuticals, and pharmaceuticals. Entry into these markets will require a level of standardization, efficacy, and traceability that has not previously been demanded of seaweed products. Both internal concentrations and composition of bioactive compounds can fluctuate seasonally, geographically, bathymetrically, and according to genetic variability even within individual species, especially where life history stages can be important. History shows that successful expansion of seaweed products into new markets requires the cultivation of domesticated seaweed cultivars. Demands of an evolving new industry based upon efficacy and standardization will require the selection of improved cultivars, the domestication of new species, and a refinement of existing cultivation techniques to improve quality control and traceability of products.

Algal eating habits of phycologists attending the ISAP Halifax Conference and members of the general public

A short questionnaire was devised during the 4th ISAP Conference in Halifax (2011) to gather some information on the algal eating habits of the participants. Responses were also collected from random members of the general public in Galway and Copenhagen. Most phycologists had eaten algae before (93%), but few conference participants ate it more regularly than per month. Responses of the general public were similar. A probability model tested the likelihood of a participant eating algae. Neither age nor nationality significantly influenced this probability, although gender increased the probability of eating algae regularly by 9% if the participant was male (at the 90% confidence limit). As hypothesised, being a conference attendee highly significantly increased the probability of eating algae by 22%, in comparison with non-conference attendees (i.e. the general public). The type of phycological research studied also had a significant effect. Researchers working with macroalgae were 22% more likely to eat algae, whereas microalgal researchers were 15% less likely to eat algae on a monthly or more regular basis. The main reasons for eating algae by both groups were ‘taste’, followed by ‘other’ (undefined) reasons, whereas the main reason for not eating algae in both groups was a ‘lack of availability’. Phycologists also ate algae for the perceived ‘health benefits’ (36%), whereas few members of the general public chose this option (13%). Consumption of red seaweeds was most popular (60% of phycologists and 71% of the general public), with Porphyra spp. most commonly preferred. In total, 27 genera of macroalgae and microalgae were recorded as eaten by questionnaire participants.

Impact of kelp cultivation on the Ecological Status of benthic habitats and Zostera marina seagrass biomass

The Ecological Status of subtidal benthic communities within a commercial kelp farm on the southwest coast of Ireland was not impacted by macroalgal cultivation. Additionally, there was no effect on the biomass of Zostera marina, a key habitat under the EU Habitats Directive and OSPAR Commission. However, sediment grain size and total organic matter (TOM) were influenced by abiotic and biotic aspects of the farm. A temporal effect on univariate and multivariate species data, Infaunal Quality Index (IQI) and Z. marina biomass was observed. This effect was likely a community response to high storm disturbance in winter 2013/14. The use of IQI to assess the impact of macroalgal cultivation on benthic communities is a novel approach. This study supports a view that environmental impacts of macroalgal cultivation are relatively benign compared to other forms of aquaculture. Further research must be conducted to understand all interactions between aquaculture activities and the environment.