Key factors influencing transport of white shrimp (Litopenaeus setiferus) post‐larvae into the Ossabaw Sound system, Georgia, USA

Abstract

We examined conditions under which white shrimp (Litopenaeus setiferus) post-larvae enter an estuarine channel receiving high freshwater discharge and one receiving negligible discharge in the Ossabaw Sound system of Georgia, USA, during 1997 and 1998. We used surface nets to collect plankton over several 14-day periods, during which consecutive tows were made at night against the flooding current at stations in the inlet channels. During these sampling periods, additional intensive periods of around-the-clock surface and near-bottom (using a bottom sled) plankton tows were made. Data on oceanographic conditions were obtained from moored instrument arrays and shipboard sampling. We identified three key factors that influenced the densities of post-larval white shrimp in time and space within the Ossabaw inlet system. The first factor was a critical minimum temperature of coastal waters of 27-28°C. Once the threshold temperature was reached, lunar tidal stage became a key factor when the full duration of the flood tide coincided with darkness during peak ingress. This peak also coincided with an increase in water level within the system by more than 0.2 m, which induced an additional influx of water that reinforces the flood current over the ingress period. Our results suggest that the direction of subtidal currents (into or out of the system) becomes a significant factor in post-larval ingress when influx of water coincides with the time of favorable temperature conditions and nighttime flood tides.

Cross-shelf transport of pink shrimp larvae: interactions of tidal currents, larval vertical migrations and internal tides

“…Below the thermocline the water temperature was 25°C, a low temperature for spawning of tropical penaeid shrimps, which prefer to spawn at temperatures between 27°C and 29°C (e.g. Wenner et al 2005). Accordingly, the low concentrations of pink shrimp larvae found at the DT station may be related to the low temperatures registered at the depth where previous authors have suggested that spawning should occur.…”

Synoptic oceanography of San Jorge Gulf (Argentina): A template for Patagonian red shrimp (Pleoticus muelleri) spatial dynamics

“…The latter, however, has not been validated by field observation. Besides, it has been well documented that penaeoid shrimp larval and post-larval transport can be partly controlled by complex behavioral responses to tidal currents (Criales et al, 2011;Rothlisberg et al, 1995;Wenner et al, 2005), which are strong in SJG (Tonini et al, 2006). Annual surveys of the distribution of eggs and pelagic larvae (e.g., Moriondo-Danovaro, 2011) are not informative about post-larval drift and connectivity, as they are conducted during the summer (spawning season) and concentrate on spawning grounds.…”

Relationship of precipitation, freshwater input, and sea level height with the abundance of the white shrimp (Litopenaeus occidentalis; Street, 1871) off Buenaventura, eastern tropical Pacific

“…Criales and Lee, 1995;Criales et al, 2003 also for Farfantepenaeus duorarum off Florida), and the direction of subtidal currents for entering the nurseries (e.g. for Litopenaeus setiferus postlarvae in Georgia, USA; Wenner et al, 2005).…”