Northwest Fisheries Science Center

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Document Type: Journal Article
Center: NWFSC
Document ID: 4786
Title: Nitrogen allocation of Gracilaria tikvahiae grown in urbanized estuaries of Long Island Sound and New York City, USA: a preliminary evaluation of ocean farmed Gracilaria for alternative fish feeds
Author: Ronald B. Johnson, Jang K. Kim, Lisa C. Armbruster, Charles Yarish
Publication Year: 2014
Journal: Algae
Volume: 29
Issue: 3
Pages: 227-235
DOI: http://dx.doi.org/10.4490/algae.2014.29.3.227
Keywords: Gracilaria tikvahiae, red seaweed, macroalgae, nitrogen, protein, amino acids, taurine.,
Abstract:

The red seaweed, Gracilaria tikvahiae McLachlan, was cultivated in open water farms in urbanized estuaries of Long Island Sound (26-30 psu of salinity) and New York City (20-25 psu), USA in 2011. Plants were harvested monthly from summer (August, 24°C) to fall (November, 13°C) and analyzed for total nitrogen, protein, and amino acid content. On a dry matter (DM) basis, nitrogen and protein significantly increased over the harvest period until October and then plateaued. Nitrogen increased from 22 ± 1 g kg-1 DM in August to 39 ± 3 g kg-1 DM in October (p < 0.001). Protein increased
from 107 ± 13 g kg-1 DM in August to 196 ± 5 g kg-1 DM in November (p < 0.001). With two exceptions, amino acid concentrations expressed on a crude protein (CP) basis were similar over the harvest period. Essential amino acids accounted for 48 ± 1% of all amino acids present with lysine and methionine averaging 56 ± 2 g kg-1 CP and 18 ± 1 g kg-1 CP, respectively. Histidine was underrepresented among essential amino acids and averaged 13 ± 1 g kg-1 CP. Taurine ranged from 2.1 to 3.2 g kg-1 DM. With its moderate levels of lysine, methionine and taurine, ocean farmed G. tikvahiae has the potential of overcoming many nutrient deficiencies currently associated with terrestrial plant ingredients in alternative feeds for fish and shrimp.

Description:

Evaluating the nutritive potential of ocean farmed Gracilaria for alternative fish feeds

Theme: Recovery, Rebuilding and Sustainability of Marine and Anadromous Species
Foci: Maximize effectiveness and minimize impacts of artificial propagation in recovery, rebuilding and stock sustainability