Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Fish larvae find the reef by orienting: The earlier the better

24.04.2012
Team of female scientists develop sophisticated numerical model to study larval behavior, fill ecological gap

The behavior of marine larvae is central to fully understanding and modeling the pelagic (open ocean) stage for many coastal organisms. For the first time, a numerical study conducted by the University of Miami (UM) incorporates horizontal larval fish navigation skills into realistic 3D flow fields, creating a powerful tool that spells out how larvae use environmental cues to find their way back to the reef after being out on the open ocean. The new model uses reliable larval swimming speeds and vertical migration, known life history traits and spawning time to create realistic scenarios that can be studied in detail.


This image shows damselfish larvae (Chromis atripectoralis) swimming freely in the open ocean, all in the same direction. In an article entitled: “Orientation behavior in fish larvae: A missing piece to Hjort's critical period hypothesis” that appears in the latest edition of the Journal of Theoretical Biology, scientists Erica Staaterman, Claire Paris and Judith Helgers demonstrate that despite very low swimming speeds -- about a few centimeters per second -- orientation behavior during early stages is critical to bringing larvae back to their juvenile habitat. In other words, baby reef-fish must possess, as early as possible, the ability to sense cues from the habitat that help them to navigate and survive their phase out in the open ocean. Credit: Ricardo Paris

In an article entitled: "Orientation behavior in fish larvae: A missing piece to Hjort's critical period hypothesis" that appears in the latest edition of the Journal of Theoretical Biology, scientists Erica Staaterman, Claire Paris* and Judith Helgers demonstrate that despite very low swimming speeds -- approximately a few centimeters per second -- orientation behavior during early stages is critical to bringing larvae back to the juvenile habitat. The research team shows that baby reef-fish must possess, as early as possible, the ability to sense cues radiating from the habitat that help them to navigate and survive the pelagic phase.

The team used Hjort's "critical period" hypothesis, which says that fish recruitment variability is driven by the fate of the earliest larval stages, and that food and "aberrant drift" are the main factors contributing to the survivorship during this early phase. According to this hypothesis, the proportion of survivors during this "critical" larval phase is carried over throughout the entire life history of the fish's population.

"Orientation during the "critical period" appears to have remarkable demographic consequences," said UM Applied Marine Physics Professor Paris. "Larvae need to orient themselves soon after hatching to increase their chance to find any reef or to come back to their home reef. This notion of 'larval homing behavior' is a new concept, but it makes sense when compared to other essential larval developmental traits such as first feeding and swimming. If early fish larvae can sense their way home, we were certainly missing an important component in current bio-physical models that would change predictions of marine population connectivity."

"Using this model we can add to Hjorts' hypothesis that 'behavior' is a main factor contributing to the survivorship of the larvae, as well," said Staaterman, a Ph.D. student at UM. "We have discovered that recruitment of reef-fish is linked to signals perceived by the pelagic larvae; if the signals disappear or weaken, larvae can get lost. Therefore, the health of the coral reef and its cues is not only critical to the adult reef-fishes, but it is also essential to the survivorship of their pelagic larvae."

This study also shows the importance of the health of the habitat, even in complex coastal circulation with eddies and counter-currents: The stronger the cue information radiating from the surrounding habitat, the higher the survival rate of the larvae.

The flexible numerical tool that was developed through this study will allow scientists to set up hypotheses about both the nature of the cues and the larval behavior of a wide variety of marine species. This knowledge will allow us to better understand the enigmatic ecological "black box" of the pelagic larval phase, and help communities to better manage marine resources.

"These kind of studies, where the paths of millions of fish larvae are simulated in a model ocean, are really only feasible with the newest generation of numerical models," said Helgers, a computer scientist who contributed to the model algorithm which is designed to answer questions on the interaction of larvae with ocean currents. "The model we have built is fast and reliable, which allows us to perform the complex computations required to track the larvae in a high resolution model ocean."

"The outcomes of this study should serve to re-focus research on basic understanding of what larvae are capable of sensing, how they use their capabilities in the pelagic environment, and finally on the sequential importance of navigational cues needed for survival," added Paris.

About the University of Miami's Rosenstiel School

The University of Miami's mission is to educate and nurture students, to create knowledge, and to provide service to our community and beyond. Committed to excellence and proud of the diversity of our University family, we strive to develop future leaders of our nation and the world. Founded in the 1940's, the Rosenstiel School of Marine & Atmospheric Science has grown into one of the world's premier marine and atmospheric research institutions. Offering dynamic interdisciplinary academics, the Rosenstiel School is dedicated to helping communities to better understand the planet, participating in the establishment of environmental policies, and aiding in the improvement of society and quality of life. For more information, please visit www.rsmas.miami.edu.

Barbra Gonzalez | EurekAlert!
Further information:
http://www.rsmas.miami.edu

More articles from Ecology, The Environment and Conservation:

nachricht Innovative grilling technique improves air quality
01.07.2020 | Fraunhofer Institute for Building Physics IBP

nachricht Traffic density, wind and air stratification influence the load of the air pollutant nitrogen dioxide
26.06.2020 | Leibniz-Institut für Troposphärenforschung e. V.

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Excitation of robust materials

Kiel physics team observed extremely fast electronic changes in real time in a special material class

In physics, they are currently the subject of intensive research; in electronics, they could enable completely new functions. So-called topological materials...

Im Focus: Electrons in the fast lane

Solar cells based on perovskite compounds could soon make electricity generation from sunlight even more efficient and cheaper. The laboratory efficiency of these perovskite solar cells already exceeds that of the well-known silicon solar cells. An international team led by Stefan Weber from the Max Planck Institute for Polymer Research (MPI-P) in Mainz has found microscopic structures in perovskite crystals that can guide the charge transport in the solar cell. Clever alignment of these "electron highways" could make perovskite solar cells even more powerful.

Solar cells convert sunlight into electricity. During this process, the electrons of the material inside the cell absorb the energy of the light....

Im Focus: The lightest electromagnetic shielding material in the world

Empa researchers have succeeded in applying aerogels to microelectronics: Aerogels based on cellulose nanofibers can effectively shield electromagnetic radiation over a wide frequency range – and they are unrivalled in terms of weight.

Electric motors and electronic devices generate electromagnetic fields that sometimes have to be shielded in order not to affect neighboring electronic...

Im Focus: Gentle wall contact – the right scenario for a fusion power plant

Quasi-continuous power exhaust developed as a wall-friendly method on ASDEX Upgrade

A promising operating mode for the plasma of a future power plant has been developed at the ASDEX Upgrade fusion device at Max Planck Institute for Plasma...

Im Focus: ILA Goes Digital – Automation & Production Technology for Adaptable Aircraft Production

Live event – July 1, 2020 - 11:00 to 11:45 (CET)
"Automation in Aerospace Industry @ Fraunhofer IFAM"

The Fraunhofer Institute for Manufacturing Technology and Advanced Materials IFAM l Stade is presenting its forward-looking R&D portfolio for the first time at...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Contact Tracing Apps against COVID-19: German National Academy Leopoldina hosts international virtual panel discussion

07.07.2020 | Event News

International conference QuApps shows status quo of quantum technology

02.07.2020 | Event News

Dresden Nexus Conference 2020: Same Time, Virtual Format, Registration Opened

19.05.2020 | Event News

 
Latest News

Quick notes in the genome

07.07.2020 | Life Sciences

Limitations of Super-Resolution Microscopy Overcome

07.07.2020 | Life Sciences

Put into the right light - Reproducible and sustainable coupling reactions

07.07.2020 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>