Data on number of dives observed and total number of larval tracks across all turbulence regimes collected at Wood Hole Oceanographic Institution in 2011 (Larvae in turbulence project)

Website: https://www.bco-dmo.org/dataset/561205
Data Type: experimental
Version: 2015-06-08

Project
» Larval Response to Turbulence During Dispersal and Settlement (Larvae in turbulence)
ContributorsAffiliationRole
Mullineaux, LaurenWoods Hole Oceanographic Institution (WHOI)Principal Investigator
Helfrich, Karl R.Woods Hole Oceanographic Institution (WHOI)Co-Principal Investigator
Wheeler, JeanetteWoods Hole Oceanographic Institution (WHOI)Student, Contact
Copley, NancyWoods Hole Oceanographic Institution (WHOI BCO-DMO)BCO-DMO Data Manager


Dataset Description

Count of number of dives observed in each dataset of four trials (T1-T4) of increasing turbulence (s0-s7), corresponding to tank forcing frequencies of 0-1.75 Hz. Dives are identified as per the method described in Wheeler et al. (2013). PIV recordings were performed by J. Wheeler in Summer 2011 and 2012.

Relevant Reference:

Wheeler J.D., Helfrich K.R., Anderson E.J., McGann B., Staats P., Wargula A.E., Wilt K., Mullineaux L.S. (2013) Upward swimming of competent oyster larvae Crassostrea virginica persists in highly turbulent flow as detected by PIV flow subtraction. Mar Ecol Prog Ser 488, 171-185.

Wheeler J.D., Helfrich K.R., Anderson E.J., Mullineaux L.S. (2015) Isolating the hydrodynamic triggers of the dive response in eastern oyster larvae. Limnol Oceanogr, (doi:10.1002/lno.10098)


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Data Files

File
dive_v_turb.csv
(Comma Separated Values (.csv), 4.97 KB)
MD5:a8181da1d4f7d150db4f625f9ec9dc09
Primary data file for dataset ID 561205

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Parameters

ParameterDescriptionUnits
exp_id

experiment identification

unitless
turb

turbulence machine dial setting

unitless
freq

oscillation frequency of double grid at amplitude 5 cm

Hz
trial

trial identification

unitless
dataset

id of 45 second video of larvae in tank

unitless
num_dives

number of dives observed in dataset

dive
num_tracks

number of tracks

tracks
prob_dive

Probability of dive (frequency of dives divided by number of larval trajectories) with respect to energy dissipation rate for each data set

unitless


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Instruments

Dataset-specific Instrument Name
Generic Instrument Name
Camera
Dataset-specific Description
high-speed monochrome camera (Photron Fastcam SA3) and a pulsed near-infrared laser (Oxford Lasers, Firefly 300 W, 1000 Hz, 808 nm)
Generic Instrument Description
All types of photographic equipment including stills, video, film and digital systems.


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Deployments

lab_Mullineaux_2011

Website
Platform
WHOI
Start Date
2011-06-01
End Date
2012-08-31
Description
Larval oysters in turbulence experiments


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Project Information

Larval Response to Turbulence During Dispersal and Settlement (Larvae in turbulence)

Coverage: Laboratory studies at Woods Hole Oceanographic Institution


Description from NSF award abstract:
The planktonic larval stage of benthic marine invertebrates provides a mechanism for exchange of individuals between remote populations. Dispersal is affected by swimming behaviors, particularly those that alter the larva's vertical position in the water. Larvae of some species change their vertical positions in response to turbulence by ceasing to swim and sinking downward (diving). By doing so, they can alter their horizontal transport in currents and increase their supply to the seafloor. The main objectives of this study are to investigate behavioral responses of oyster (Crassostrea virginica) larvae to turbulence in the water column and at the seafloor, and to determine how these behaviors affect settlement. The investigators hypothesize that diving behavior enhances settlement into suitable habitat, even where mean bed shear stress is high. They expect that once larvae approach the bottom, they can take advantage of temporal and spatial refuges (such as turbulent lulls in the lee of roughness elements) to settle in otherwise harsh conditions. Investigating larval responses to turbulence is a challenge because it requires simultaneous measurement of time-variant flows and larval behaviors. The investigators will modify a conventional particle image velocimetry (PIV) approach so it can be used to track larval motions and fluid velocities simultaneously. PIV provides information on flow kinematics (e.g., rotation and strain rate) in the immediate vicinity of a larva, as well as bulk dissipation rates and measures of Taylor and integral length scales that likely influence larval acceleration. When these measurements are coupled with a larval trajectory, they provide a history of the fluid environment a larva experiences, and can be used to determine what characteristic of turbulence triggers the diving behavior. They also make it possible to calculate the bottom shear stress an individual larva experiences when it encounters the bottom and attempts to settle. The investigators will examine turbulence effects on larval behaviors in the water column using a grid-stirred tank. They will use a racetrack flume to test the hypothesis that larval settlement success depends on the frequency of lulls of sufficient duration for larval attachment.

Laboratory experiments will provide a mechanistic understanding of larval behavior that can be used in general theoretical models exploring how behavior influences dispersal and population connectivity. The quantified swimming responses of oysters are critical input for coupled bio-physical models of dispersal in the field. An understanding of larval behavior contributes to our ability to predict the effects of natural and anthropogenic perturbations (some of which are linked to global climate change) on benthic communities in coastal ecosystems where turbulence and habitat suitability vary spatially. This information is critical for informed decision making on shellfish management and design of marine reserves. The technique developed for simultaneous PIV and larval tracking will open new questions in larval ecology and be broadly applicable to studies of plankton interactions with turbulence.



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Funding

Funding SourceAward
NSF Division of Ocean Sciences (NSF OCE)

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