sturgeon research

Current White sturgeon research is split into 3 active areas below. Please click on each one for a detailed description.

Spawning

Spawning research consists of monitoring spawning events in previously identified spawning locations, as well as looking for new spawning locations. This monitoring is conducted to identify when and how frequently spawning occurs and more recently, to determine numbers of adults spawning at different locations.

Egg mats  are the primary method used to collect fertilized eggs in the River. These are large steel framed mats containing coarse material (e.g. furnace filter material) that lay on the river bottom in spawning areas. When a female sturgeon spawns, she broadcasts her eggs near the bottom of the river.  The eggs are sticky and adhere to the mat material. When the mats are retrieved, the eggs are counted and staged to estimate when the spawning even occurred (based on the development of the egg and the temperature of the river). These data provide insight into the number of spawning events that occur in a given year. These data are then examined in comparison to water temperatures and river flows to help determine spawning cues and describe the reproductive biology of white sturgeon. A small number of the fertilized eggs are incubated at the site to improve survival to hatch and collect tissue for genetic analysis.

Another method used to monitor white sturgeon spawning events is drift nets. Drift nets are used to monitor the dispersal of larval white sturgeon, and to aid in finding new spawning locations.  These nets are also successful in collecting fertilized eggs when placed immediately downstream from known spawning locations. This method was successful in recently identifying a new spawning location HLK and ALGS.  The drift nets have a metal framed opening in the shape of a “D” (these nets are also known as “D-Rings”), with a 3 metre tapering net with a collection bottle attached to it. The net sits just off of the bottom of the river, allowing white sturgeon larvae drifting passively with the current to be captured (photo here?) in the collection bottle. The nets are retrieved twice daily, where the collection bottles are changed and the material in the collection bottle is checked for larval white sturgeon presence (suggesting spawning took place upstream of that location. This technique has identified a spawning location downstream of the Kinnaird bridge, a location that will be the focus of monitoring in the coming years.

Juveniles

Over 100,000 juvenile white sturgeon have been released into the transboundary portion of the upper Columbia River between 2002 and 2012. An annual juvenile white sturgeon capture program is conducted to describe important parameters related to growth, survival and distribution in the lower Columbia River. A secondary objective is to identify juveniles that are of wild origin to determine specific years where recruitment may have occurred.

Juveniles are collected using three methods: gill nets, set lines, and angling. Captured juveniles are scanned for a Passive Integrated Transponder (PIT) tag and weighed and measured for length.  On rare occasions a wild juvenile is captured, it is marked using a PIT tag and in certain cases an acoustic tag so its movements’ can be monitored. To date, 0.5% of the fish captured have been of wild origin, and the remainder were stocked from hatcheries in Canada and the United States.   The distribution of fish throughout the lower Columbia River has been examined. High habitat has been documented in the Robson stretch, near Kinnaird, and downstream near Waneta. Generally, older ages represented larger proportions of the total catch (e.g., 25% 9 year olds) but all hatchery release ages were represented within the high use areas. Average annual growth rates were extremely high and ranged from 14 cm in fork length for younger fish (1-3) and 10 cm per year for older aged juveniles (4-8). Average annual weight increases were smaller for younger fish (1-4) and larger for older ones (age 5-8), suggesting that growth in total length is more important in the early years than weight.   Diet preferences in the upper section near Robson appear to be primarily composed of mysid shrimp, an introduced food source. It is estimated that 25% of juveniles survive the first year of live and 85% or greater survive annually from that point until they are adults.

Adults

The lower Columbia River adult sturgeon monitoring is an annual program to monitor changes in age structure, population estimates, and population demographics. Included is an intensive acoustic telemetry component over the next 10 years, that will provide information on general movements, habitat use and population interactions, and potentially the identification of new/alternate spawning locations in the lower Columbia River.   The monitoring program will also provide periodic spawn monitoring to measure trends in the numbers of spawning events, population demographics and reproductive potential, and provide an annual broodstock contribution to the conservation aquaculture program. The monitoring program is designed to address a number of information requirements related to the adult life stage, but it will also provide a long term data set that will provide:

(i) input to the ongoing consideration of recruitment failure hypotheses and the evaluation of the effects of future management responses on spawning success; and

(ii) information to guide broodstock collection and stocking targets related to future conservation aquaculture programs and related recovery research initiatives.

The primary objectives for this program are to describe:

1) Adult sturgeon life history characteristics including size, growth, age structure, condition, and population characteristics including abundance, population trajectory, mortality rates, genetic status and reproductive potential.

2) Biological characteristics including spawn monitoring to assess timing, success and general trends; and movements to assess seasonal habitat use and spawning site selection under the current range of operating conditions are defined.

A quantitative baseline of adult information needs identified in items 1) and 2) above has been established and maintained for the program period (2008-2019). Acoustic telemetry is used to determine movement patterns, identify habitat use, and identify new spawning areas. Transmitters (tags) are surgically implanted into the fish (primarily adults), and regularly “ping” every (30-120 seconds).  The data are received and logged by remote receivers stationed at various locations along the river and downloaded periodically by researchers. Movement data collected to data has shown that sturgeon have high residency time for a single location with peak movements occurring during the spring and summer months Examination of individual movement patterns has helped to locate new spawning areas and more effectively identify and evaluate critical habitat.

Reports related to adult work can be found here.