Modeling herring and hake larval dispersal in the Salish Sea

Evgeniva presents “Modeling herring and hake larval dispersal in the Salish Sea” as part of the joint PCIC-PICS Pacific Climate Seminar Series.

Herring and hake are commercially important fish in Strait of Georgia. In this study, larval particles of these species are tracked for up to six weeks after they hatch using ROMS (Regional Ocean Modeling System) and Lagrangian particle tracking model (LTRANS). Particles with different behavior (such as floaters at different depths or performing diel vertical migration) are traced in the springs of the years 2007-2009. Since herring larval particles stay in the top 12m, their distribution is strongly dependent on the winds. As there are no strong mean currents in the Strait, there is no simple transport path; advection is sensitive to the day and position of release.  Even over four weeks, few particles released in the northern part of the Strait travel to the southern part and vice versa. However, particles do cross the strait.  Due to the Fraser River plume, shear in the 12 m is strong in the southern Strait and particle advection is dependent on exact depth.  In other locations, shear is much weaker. On the other side, hake larvae particles reside deeper in the water column (50-200m) and the distribution of the particles in the central Strait is shaped by a deep gyre. Behavior changes distribution for both types of larvae particles but there is no pattern. This study is a first look at the connectivity of the Strait of Georgia from the perspective of herring and hake larvae.

Biography: Evgeniya (Jenny) Snauffer is a research assistant working for VENUS - the undersea observatory located in the Strait of Georgia (venus.uvic.ca). She provides technical support when utilizing data collected with instruments placed on the BC ferries. After getting a degree in Mathematics from Sofia University (Bulgaria), she worked as an IT specialist for a few years. Eventually, she moved to Vancouver where she recently graduated from the Physical Oceanography program at the University of British Columbia. For her Masters project she modeled larval behavior in the Straits of Georgia and Juan De Fuca. Please come and hear about herring larvae travel stories!