Inter-Research > MEPS > v433 > p131-148  
Marine Ecology Progress Series

via Mailchimp

MEPS 433:131-148 (2011)  -  DOI:

Swimming behavior and velocities of barnacle cyprids in a downwelling flume

Claudio DiBacco1,*, Heidi L. Fuchs2, Jesús Pineda3, Karl Helfrich3

1Fisheries and Oceans Canada, Bedford Institute of Oceanography, PO Box 1006, Dartmouth, Nova Scotia B2Y 4A2, Canada
2Institute of Marine and Coastal Sciences, Rutgers University, New Brunswick, New Jersey 08901, USA
3Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543, USA

ABSTRACT: It has been proposed that barnacle cyprids can maintain position in shoreward-propagating fronts by swimming upward against a downwelling flow, potentially mediating onshore transport of larvae toward intertidal habitat. This study developed a novel flume to characterize swimming behavior of barnacle cyprids in a laboratory downwelling flow. Seawater was pumped through a cylindrical observation chamber fitted with diffusers to produce a homogeneous downwelling velocity field. The flume generated plug flow with mean downwelling velocities (indicated by negative sign) of 0 to –47.3 mm s–1. Behavior experiments were done with wild Semibalanus balanoides cyprids. Vertical swimming rates and behaviors were estimated from video observations, and a mixture model was used to estimate velocity distributions for distinct behavioral modes. Larvae exhibited multiple behaviors but typically swam upward in response to downwelling, with a maximum estimated vertical velocity of 72.3 mm s–1. When faced with downwelling flows, cyprids alternated between upward swimming and downward swimming to maintain their vertical position in the chamber. As downwelling velocities increased, cyprids that remained in the field of view of the cameras exhibited faster mean upward swimming velocities. It is unclear how long individual S. balanoides cyprids can maintain depth, but cyprids were able to maintain depth throughout the 2 min observation period. This study supports earlier hypotheses based on field observations by demonstrating that S. balanoides cyprids swim well enough to counter downwelling velocities characteristic of convergence zones. Swimming against downwelling flow could be an adaptive behavior that enables shoreward transport in the absence of any larval ability to swim toward shore or even to sense its direction.

KEY WORDS: Downwelling flume · Barnacle · Cyprids · Semibalanus balanoides · Convergence zones · Larval behavior

Full text in pdf format
Cite this article as: DiBacco C, Fuchs HL, Pineda J, Helfrich K (2011) Swimming behavior and velocities of barnacle cyprids in a downwelling flume. Mar Ecol Prog Ser 433:131-148.

Export citation
Share:    Facebook - - linkedIn

 Previous article Next article