A Study of the Potential Impact of Dredging the Corpus Christi Ship Channel on Passive Particle Transport

Eirik Valseth,Clint Dawson,Mark D Loveland,Edward J Buskey

doi:10.3390/jmse9090935

Eirik Valseth, Clint Dawson + Show 2 more

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https://doi.org/10.3390/jmse9090935

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Abstract

We present a study of the potential impact of deepening the Corpus Christi Ship Channel through Aransas Pass; in particular, we study the effect on the transport of red drum fish larvae due to the change in channel depth. The study was conducted by high resolution simulation of the circulation of the seawater entering and exiting the pass for the current and proposed Ship Channel depths. The computer model incorporates tides and meteorological forcing and includes the entire Gulf of Mexico and the North American Atlantic coast. The corresponding transport of larvae modeled as passive particles due to the sea water circulation is established by releasing particles in the nearshore region outside Aransas Pass and subsequently tracking their trajectories. We compare the difference in the number of larvae that successfully reach appropriate nursery grounds inside Aransas Pass for four distinctive initial larvae positions in the nearshore region. Our results indicate that the change in channel depth does not significantly alter the number of red drum larvae that reach suitable nursery grounds, overall, across all considered scenarios, we see a net increase of 0.5%.

Highlights

IntroductionNear the Ship Channel, there are numerous seagrass beds and regions that serve as nursery grounds for estuarine dependent fish larvae such as red drum (Sciaenops ocellatus) [2]
Corpus Christi Ship Channel extends from the Gulf of Mexico to the Port of CorpusChristi (POCC) through Corpus Christi Bay and Aransas Pass Inlet [1]
In the figures we present where the bathymetry is shown, the color scale always refers to the water surface elevation above North American Vertical Datum of 1988 (NAVD88)

Summary

Introduction

Near the Ship Channel, there are numerous seagrass beds and regions that serve as nursery grounds for estuarine dependent fish larvae such as red drum (Sciaenops ocellatus) [2]. Along with an expansion of the Port of Corpus Christi, and in an effort to accommodate larger ships, it has been proposed to deepen the channel to 21.33 m (70 ft). Such a change in bottom topography is likely to lead to changes in the flow characteristics of the water entering and exiting through Aransas Pass and may impact the transport of fish larvae [2,3]

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