Modeling the processes affecting larval haddock (Melanogrammus aeglefinus) survival on Georges Bank

The ultimate goal of early life studies of fish over the past century has been to better understand recruitment variability. Recruitment is the single most important natural event controlling year-class strength and biomass in fish populations. As evident in Georges Bank haddock, Melanogrammus aeglefinus, there is a strong relationship between recruitment success and processes occurring during the planktonic larval stage. Spatially explicit coupled biological-physical individual-based models are ideal for studying the processes of feeding, growth, and predation during the larval stage. This thesis sought new insights into the mechanisms controlling the recruitment process in fish populations by using recent advances in biological-physical modeling methods together with laboratory and field data sets. Interactions between feeding, metabolism and growth, vertical behavior, advection, predation, and the oceanic environment of larval haddock were quantitatively investigated using individual-based models. A mechanistic feeding model illustrated that species-specific behavioral characteristics of copepod prey are critically important in determining food availability to the haddock larvae. Experiments conducted with a one-dimensional vertical behavior model suggested that larval haddock should focus on avoiding visual predation when they are small and vulnerable and food is readily available. Coupled hydrodynamics, concentration-based copepod species, and individual-based larval haddock models demonstrated that the increased egg hatching rates and lower predation rates on larvae in 1998 contributed to its larger year-class. Additionally, results from these coupled models imply that losses to predation may be responsible for interannual variability in recruitment and larval survival. The findings of this thesis can be used to better manage the haddock population on Georges Bank by providing insights into how changes in the physical and biological environment of haddock affect their survival and recruitment, and more generally about the processes significant for larval fish survival.

Department dc:contributor.department

Joint Program in Oceanography/Applied Ocean Science and Engineering

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2011

Author dc:creator

• Petrik, Colleen Mary

Advisor dc:contributor.advisor

• Cabell S. Davis.

• Joint Program in Oceanography/Applied Ocean Science and Engineering.
• Biology.
• Woods Hole Oceanographic Institution.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/62788

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/62788