Fate and transport of Asian carp eggs in spawning rivers

Garcia Botero, Tatiana

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https://hdl.handle.net/2142/73041 Copy

Description

Title

Fate and transport of Asian carp eggs in spawning rivers

Author(s)

Garcia Botero, Tatiana

Issue Date

2015-01-21

Director of Research (if dissertation) or Advisor (if thesis)

Garcia, Marcelo H.

Doctoral Committee Chair(s)

Garcia, Marcelo H.

Committee Member(s)

• Valocchi, Albert J.
• Liu, Wen-Tso
• Jackson, P. Ryan

Department of Study

Civil & Environmental Eng

Discipline

Civil Engineering

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

Ph.D.

Degree Level

Dissertation

Keyword(s)

• FluEgg
• Asian carp
• Eggs, Lagrangian model
• Spawning
• Turbulence
• Individual-based model (IBM)
• Synthetic eggs
• Laboratory experiments
• Suspension
• Settling

Abstract

In recent years the population of Asian carp has increased exponentially in the Mississippi River Basin. This invasive species are filter feeders that consume phytoplankton and zooplankton thus competing directly with native species as their diets overlap. Asian carp can lay thousands of eggs and have the potential to spawn up to three times per year. Moreover, there is a growing concern about Asian carp invading the Great Lakes, which could cause negative ecological and economic impact. Asian carp eggs are semi-buoyant and must remain suspended in the water column to survive, supported by the turbulence of the flow, until they hatch and develop the ability to swim. Determining if Asian carp will use a given river for spawning and recruitment is typically determined by comparing a river to those where spawning and recruitment were observed. This observation-based technique has led to general guidelines about the river length and hydraulic characteristics required for Asian carp spawning and recruitment. Previous estimates of the minimum river length or stream velocities required to keep eggs in suspension have not consider the non linearity of the hatching dynamics of different river systems. In reality, minimum river length (drifting time) required for egg hatching depends primarily on water temperature and the river's hydrodynamics. Today, there is no a clear understanding and consensus about the hydrodynamic conditions at which eggs are transported and remain in suspension. In this thesis, we developed the Fluvial Egg Drift Simulator (FluEgg), a three-dimensional Lagrangian model to simulate the transport dynamics of Asian carp eggs. FluEgg tracks individual virtual eggs as they drift through the current during the life stages before hatching. The FluEgg model incorporates information about Asian carp egg development and river hydrodynamics to provide insights regarding: (i) the likelihood of a river to be suitable for spawning, (ii) the potential of a river to transport Asian carp eggs in suspension until hatching, and (iii) the identification of the location of Asian carp eggs at different developmental stages. This research contributes valuable information about the transport, and dispersal patterns of Asian carp eggs, and assists in the identification of critical hydrodynamic conditions that maintain eggs in suspension. The FluEgg model was applied to two Great Lakes tributaries to predict transport and dispersion of Asian carp eggs in two different river systems. Results depict the dynamic component associated with egg transport and dispersion, and egg-hatching risk due to the interactive relation between river length, hydrodynamic characteristics, and water temperatures. Results indicate that drifting distances to enable hatching depend strongly on the river hydrodynamics and on the water temperature. Therefore, depending on the environmental and hydrodynamic characteristics of the river, drifting distances can be much shorter than the 100 km previously assumed to be adequate based on the observation of native spawning rivers. However, as the developmental rates of Asian carp eggs depend on water temperature, small changes in temperature might result in longer river reaches to support egg hatching. Going one step further from the numerical modeling of the transport and dispersion of Asian carp eggs, laboratory experiments using surrogate eggs mimicking the physical properties of water-hardened eggs, were performed in a temperature controlled recirculatory flume with a sand bed. Surrogate eggs were allowed to drift under different velocity conditions. Egg drifting behavior, and suspension and settling dynamics were observed. It was observed that at high velocities (V≥ 0.2 m/s) eggs were suspended and distributed throughout the water column, eggs that touched the sand bed were re-entrained by the flow. At lower velocities (V≥ 0.57m/s) some settling of the eggs was observed. Egg settling zones were located in the sand bed near the walls of the flume and in the lee side of the bedforms. In summary, my research explains the dynamics of the transport and fate of Asian carp eggs in spawning rivers by using numerical simulations performed by the FluEgg model together with laboratory experiments using surrogate eggs. Results from this thesis are useful for scientists, managers, and stakeholders both to improve their understanding of drifting behavior of Asian carp in early life stages, that is before the eggs hatch and develop the ability to swim, and to facilitate their decision making processes. Finally, the FluEgg model can not only be used as a tool to evaluate the transport of Asian carp eggs but also to simulate the transport of eggs of other fish species, and assess the transport of other passive particles.

Graduation Semester

2014-12

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http://hdl.handle.net/2142/73041

Copyright and License Information

Copyright 2014 Tatiana Garcia Botero

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