Physiological processes and gross energy budget of the submerged longline-cultured Pacific oyster Crassostrea gigas in a temperate bay of Korea

Abstract

Physiological processes and gross energy budget of the longline-cultured Pacific oyster Crassostrea gigas were investigated in Geoje–Hansan Bay, Korea during two entire culturing periods. Based on physiological measurements of food consumption, feces production, ammonium excretion, and respiration from July 2008 to February 2009 and from July 2013 to February 2014, scope for growth appeared to be positive during most of the culturing period, except for one period with extremely high temperatures (up to 25°C). Estimates of physiological energy production matched well with tissue energy increment measured by gross biochemical composition during the culturing period, suggesting that the oysters might adjust their physiological performance to relatively low concentrations of suspended particulate matter in the bay to optimize energy acquisition. Such an adaptive adjustment includes an increased absorption of energy and a reduced loss of metabolic and excretory energy, resulting in positive production under high culturing density. Using physiological measurements, we further assessed the feedback effects of the longline aquaculture of oysters on the bay system. Ecological efficiency, estimated by a series of energetic efficiencies at the whole bay level, was low compared with Lindeman’s law of trophic efficiency. Biodeposition and ammonia excretion rates in this study were relatively low compared with other intertidal plastic bag cultures. These results indicate that the cultured oysters might have only minor effects on benthic and pelagic environments of the bay. Overall, our results suggest that the adaptive physiological performance of oysters and consequently weak feedback effects on ambient habitats should facilitate sustainable longline aquaculture in the bay for a prolonged period without severe habitat deterioration.

Testing a Model of Pacific Oysters’ (Crassostrea gigas) Growth in the Adriatic Sea: Implications for Aquaculture Spatial Planning

“…No growth, or even decrease in wet weight, was observed at the sampling site between July and September 2018, when water temperatures often exceeded the 25 • C threshold identified by [31]. This result is consistent with that presented in [53], who compared two grow-out cycles: the first one characterized by summer temperatures >25 • C, in which individual growth stopped, and a second one with temperatures lower than 22 • C, in which oysters continued growing throughout the summer. Nonetheless, our results are not entirely consistent with previous work on oyster growth in the Adriatic Sea, since [54] observed maximum weight increment between July and October.…”

Seasonal energetic physiology in the ark shell Anadara kagoshimensis in response to rising temperature

“…It has long been documented that the filtration rates (as reported using the ingestion rate in the present study) of suspension-feeding bivalves are highly susceptible to changes in diet quality and quantity (Bayne and Newell, 1983;MacDonald et al, 2016). The measurement of filtration rates in the presence of cultivated microalgal diets yields consistently overestimated rates compared with those obtained using natural seston (Bayne and Newell, 1983;Jørgensen, 1996;Lee et al, 2018). The low exponent values found for A. kagoshimensis suggest that the relative suppression of feeding activity in larger individuals plays a part in lowering the exponent value in the experimental conditions of natural seston diets (Hatton et al, 2005).…”

Thermal effect on energetic physiology in the ark shell Scapharca subcrenata

“…It has long been documented that the filtration rates of suspensionfeeding bivalves are highly susceptible to changes in diet quality and quantity [3,55]. The measurement of filtration rates in the presence of cultivated microalgal diets yields consistently overestimated rates compared with those using natural seston [357,58]. The low exponent values found for S. subcrenata suggest that a relative suppression of feeding activity in larger individuals plays a part in lowering the exponent value in the experimental conditions of natural seston diets [59].…”