Growth and biofouling in kelp aquaculture (Saccharina latissima): the effect of location and wave exposure

Wouter Visch,Göran M Nylund,Henrik Pavia

doi:10.1007/s10811-020-02201-5

Wouter Visch, Göran M Nylund + Show 1 more

Open Access

https://doi.org/10.1007/s10811-020-02201-5

Copy DOI

Abstract

Seaweed aquaculture is receiving increasing attention for food and non-food applications in Europe, where it is still an emerging industry. The cultivation of seaweeds in the sea is attractive as it does not compete with agricultural crops for land and freshwater, whilst generating high yearly biomass yield. The selection of suitable cultivation sites in coastal waters is essential for the sustainable establishment and further development of seaweed aquaculture in Europe. Here, we investigate the effects of wave exposure and geographic location on growth and biofouling of kelp (Saccharina latissima), using a transplantation experiment along the Swedish west coast. Biofouling of kelp decreased with increased wave exposure, from 10 and 6% coverage at sheltered and moderately exposed locations, respectively, to 3% at exposed locations. Growth, measured as blade surface area, generally increased with decreased wave exposure, with approximately 40% less growth at exposed locations compared to sheltered or moderately exposed location. We identified that there is large spatial variation in growth and fouling of the seaweed biomass at the selected farm sites, with significant differences from the km-scale to the m-scale. In addition, exposure level affected the tissue composition, with a high carbon, but low nitrogen and water content at exposed locations compared to moderate and sheltered sites. Isotope signatures (i.e. δ13C and δ15N) also differed between exposure levels. Together, these results indicate that wave exposure is an important factor to consider in site selection for both yield as well as quality of the seaweed biomass for future kelp farms.

Highlights

There is a growing interest in seaweed cultivation for food and non-food applications (Holdt and Kraan 2011)
Recent studies have shown that European temperate coastal regions offer excellent environmental conditions for the cultivation of different kelp species, not least the sugar kelp, Saccharina latissima, which is ubiquitously found at the rocky shores of the North Atlantic (Sanderson et al 2012; Marinho et al 2015; Peteiro et al 2016; Stévant et al 2017)
The biofouling of the seaweed blades was interactively affected by exposure and region (Table 1)

Summary

Introduction

There is a growing interest in seaweed cultivation for food and non-food applications (Holdt and Kraan 2011). Recent studies have shown that European temperate coastal regions offer excellent environmental conditions for the cultivation of different kelp species, not least the sugar kelp, Saccharina latissima, which is ubiquitously found at the rocky shores of the North Atlantic (Sanderson et al 2012; Marinho et al 2015; Peteiro et al 2016; Stévant et al 2017)

Objectives

Methods

Results

Conclusion