Harrison, PJ and Hurd, CL, Nutrient physiology of seaweeds: application of concepts to aquaculture, Cahiers De Biologie Marine, 42, (1-2) pp. 71-82. ISSN 0007-9723 (2001) [Refereed Article]
Copyright 2001 Cahiers De Biologie Marine
Official URL: http://www.sb-roscoff.fr/cbm/article.htm?execution...
For a particular species grown in an aquaculture system, it is important to know the C:N:P ratio of the seaweed under nutrient saturating conditions. This information will make the delivery of C, N, and P more economical. Nutrient uptake rates vary considerably with various physical, chemical and biological factors. In particular, light and temperature influence nutrient uptake rates, but we require further research to fully understand their effects. Nitrate uptake by some seaweeds is light dependent (i.e. diel periodicity), while ammonium uptake may be less dependent on light. Growth rates on different nitrogen sources (NO3-, NH4+, urea or combinations of these) should be tested. A wide variety of biological factors such as interplant variability, nutritional history, type of tissue, life history stages/age, surface area:volume ratio of the thallus and morphological changes such as the production of hairs may influence nutrient uptake rates.
Some seaweeds show three phases of uptake of the limiting nutrient (especially NH4+) when it is added to N-limited seaweeds. The "surge" uptake rate is greater than the growth rate and hence the seaweed can overcome its nitrogen deficiency. This "surge" uptake may be used to advantage in adding pulsed NH4+ additions at night to reduce competition with epiphytes. Epiphytes can also be controlled by starving the seaweed of N for several days until the tissue N (i.e. stored N) decreases to a critical level (below which the growth rate will decrease).
|Item Type:||Refereed Article|
|Research Division:||Biological Sciences|
|Research Group:||Plant Biology|
|Research Field:||Phycology (incl. Marine Grasses)|
|Objective Division:||Animal Production and Animal Primary Products|
|Objective Group:||Fisheries - Aquaculture|
|Objective Field:||Fisheries - Aquaculture not elsewhere classified|
|Author:||Hurd, CL (Associate Professor Catriona Hurd)|
|Web of Science® Times Cited:||53|
|Deposited By:||IMAS Research and Education Centre|
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