The Effect of Nutrient Availability and Light Conditions on the Growth and Intracellular Nitrogen Components of Land-Based Cultivated Saccharina latissima (Phaeophyta)

Lone Sunniva Jevne,Silje Forbord,Yngvar Olsen

doi:10.3389/fmars.2020.557460

Lone Sunniva Jevne, Silje Forbord + Show 1 more

Open Access

https://doi.org/10.3389/fmars.2020.557460

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Abstract

With the increasing interest and activities regarding seaweed cultivation in Europe, it is becoming crucial to utilize the opportunities that lies within environmental resources, such as light and nutrients, to produce biomass of a high yield and quality. The chemical composition of seaweed varies between seasons and depths as an effect of resource supply and environmental conditions. These factors are particularly important to assess for economically feasible species like the kelp Saccharina latissima. This paper examines how differences in light conditions and nutrient availability affect the growth and intracellular nitrogen in S. latissima. This was done through cultivating sporophytes in land-based tanks with four different combinations of high/low light and high/low nutrient supply over an experimental period of 20 days, with measurements of growth rate and subsequent analysis of tissue nitrogen metabolites. The results revealed that the mean growth rate and the intracellular nitrogen components of the sporophytes were positively related to the external nitrate concentration during the experimental period, indicating that S. latissima requires high nutrient concentration to maintain a rapid growth.

Highlights

Seaweed cultivation is increasing rapidly along the North Atlantic coasts (Stévant et al, 2017; Grebe et al, 2019; Forbord et al, 2020), while farming of seaweed has been an established industry for decades in many Asian countries, producing over 30 million metric tons per year (FAO, 2020)
The present study was designed to determine the effects of varying environmental conditions on the growth and nitrogen metabolites of cultivated S. latissima
The experiment confirmed a positive relationship between total intracellular nitrogen components (QN, protein and Intracellular N-Components and Intracellular Nitrate (I-DIN)) and external inorganic nitrate, and between growth rate and external nitrate

Summary

Introduction

Seaweed cultivation is increasing rapidly along the North Atlantic coasts (Stévant et al, 2017; Grebe et al, 2019; Forbord et al, 2020), while farming of seaweed has been an established industry for decades in many Asian countries, producing over 30 million metric tons per year (FAO, 2020). One of the most common and promising species for large scale cultivation in Norway is the kelp Saccharina latissima (Linnaeus) with a production of 174 metric tons in 2018 and 66 metric tons in 2019 (Directorate of Fisheries 2020) It has a high potential of growth (Handå et al, 2013; Peteiro and Freire, 2013; Bak et al, 2018; Sharma et al, 2018), high content of valuable components (Holdt and Kraan, 2011; Schiener et al, 2015; Bak et al, 2019) and a well described life cycle (Flavin et al, 2013; Redmond et al, 2014; Forbord et al, 2018). Because S. latissima can store nutrients as internal nitrate in the vacuoles (Hurd et al, 2014) and grow at relatively low temperatures, they benefit from growing in temperate areas where the nutrient availability varies over the seasons (Pedersen and Borum, 1996; Gordillo, 2012)

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