Tolerance of un‐ionized ammonia in live feed cultures of the calanoid copepod Acartia tonsa Dana. (9th April 2013)

• Record Type: Journal Article
• Authors: Jepsen, Per M; Andersen, Claus V B; Schjelde, Johannes; Hansen, Benni W
• Is Part Of: Aquaculture research. Volume 46:Number 2(2015)
• Page Start: 420
• Page End: 431
• Publication Date: 2013-04-09
• Subjects: Aquaculture -- Periodicals; Fishery management -- Periodicals; 639.8
• DOI: 10.1111/are.12190
• Languages: English
• ISSNs: 1355-557X

Abstract

<abstract abstract-type="main" id="are12190-abs-0001"> <title>Abstract</title> <p>Optimal water quality is considered as being a restriction for marine copepod cultures for live feed. There is a lack of knowledge on the water‐quality conditions in copepod cultures and the effect on copepods. Few studies have investigated the effect of ammonia on copepods, and fewer reports No Observed Effect Concentrations (NOEC) and Lowest Observed Effect Concentrations (LOEC), which provides safety levels before cultures are affected. This study investigates the tolerance of <italic>Acartia tonsa</italic> nauplii and adults to ammonia, using mortality as the endpoint after 24, 48 and 72 h of exposure. Nauplii were exposed to levels from 0 to 5127 μg NH<sub>3</sub> L<sup>−1</sup> and adults to levels from 0 to 8481 μg NH<sub>3</sub> L<sup>−1</sup>. Nauplii NOEC was 30 μg NH<sub>3</sub> L<sup>−1</sup> and LOEC was 81 μg NH<sub>3</sub> L<sup>−1</sup>. Adult NOEC was 477 μg NH<sub>3</sub> L<sup>−1</sup> and LOEC was 1789 μg NH<sub>3</sub> L<sup>−1</sup>. 50% Lethal Concentrations (LC<sub>50</sub>) for nauplii of 48 and 72 h was 1257 and 220 μg NH<sub>3</sub> L<sup>−1</sup>. LC<sub>50</sub> for adults was 2370 (24 h), 972 (48 h) and 770 (72 h). Combining NOEC with excretion rates of NH<sub>4</sub>/NH<sub>3</sub> a model was developed to calculate densities in batch cultures. We recommend that for batch cultures of <italic>A. tonsa</italic>, NH<sub>3</sub> is kept below NOEC for nauplii and that levels of NH<sub>3</sub> together with pH are monitored weekly.</p> </abstract>