CDFWA15

Currently there is little known about rearing, migratory behavior, and general emigration patterns of juvenile southern Distinct Population Segment (sDPS) North American green sturgeon (Acipenser medirostris) and white sturgeon (Acipenser transmontanus) within the Lower Sacramento River, Sacramento-San Joaquin Delta (Delta), and San Francisco Bay. This data is crucial for improved species management in California’s Central Valley.

To better understand emigration, California Department of Fish and Wildlife is undertaking a study to capture up to 100 green sturgeon and 100 white sturgeon annually and tag them with 69 kHz acoustic transmitters. Sampling is conducted by deploying and tending a 300-ft gill net with two-inch mesh. Acoustic transmitters are surgically implanted into the peritoneal cavity; tag size and therefore tag battery life is determined by fish weight and peritoneal cavity size.

Passive integrated transponder (PIT) tags are also implanted in the peritoneal cavity during the surgical procedure. An array of 69 kHz acoustic receivers deployed throughout the lower Sacramento River and Sacramento-San Joaquin Delta collects detection data for juvenile sturgeon tagged with unique tag identification numbers. Telemetry data is analyzed to determine movement patterns, rearing habitat utilization, and migratory behavior within the Delta and outmigration to the Pacific Ocean as a function of water year type and juvenile age class.