Migration and Movement Patterns of Green Sturgeon (Acipenser medirostris) in the Klamath and Trinity rivers, California, USA

Abstract

Green sturgeon, Acipenser medirostris, movement and migration within the Klamath and Trinity rivers were assessed using radio and sonic telemetry. Sexually mature green sturgeon were captured with gillnets in the spring, as adults migrated upstream to spawn. In total, 49 green sturgeon were tagged with radio and/or sonic telemetry tags and tracked manually or with receiver arrays from 2002 to 2004. Tagged individuals exhibited four movement patterns: upstream spawning migration, spring outmigration to the ocean, or summer holding, and outmigration after summer holding. Spawning migrations occurred from April to June, as adults moved from the ocean upstream to spawning sites. Approximately 18% of adults, those not out mignation in the spring, made spring postspawning outmigrations. The majority of adults, those not outmigrating in the spring, remained in discrete locations characterized as deep, low velocity pools for extended periods during the summer and early fall. Fall outmigration occurred when fish left summer holding locations, traveled rapidly downstream, and exited the river system. High river discharge due to the onset of winter rainstorms and freshets appear to be the key environmental cue instigating the fall outmigration.

Migrations and movements of adult Chinese sturgeon Acipenser sinensis in the Yangtze River, China

“…Ultrasonic telemetry has been used to study migrations and movements of many acipenseriforms. The migrations of green sturgeon Acipenser medirostris Ayres 1854 in the Sacramento, Klamath and Trinity Rivers, CA, U.S.A. were described using ultrasonic telemetry (Benson et al , 2007; Heublein et al , 2009). Additionally, ultrasonic telemetry was also employed to study partial or entire migrations of gulf sturgeon Acipenser oxyrinchus desotoi Vladykov 1955, white sturgeon A. transmontanus Richardson 1836, shortnose sturgeon A. brevirostrum LeSueur 1818, Atlantic sturgeon Acipenser oxyrinchus Mitchill 1815, in fresh water (Kieffer & Kynard, 1993; Fox et al , 2000; Parsley et al , 2008; Fernandes et al , 2010).…”

“…The upstream pre‐spawning migrations of A. brevirostrum varies depending on sex and energetic conditions of fish with day length triggering departure from wintering sites and a high river discharge triggering upstream migration for foraging or pre‐spawning holding (Kynard 1997; Kieffer & Kynard, 2012). The timing of up‐migration of southern A. medirostris in the Sacramento River was in March and April while the northern A. medirostris entered later in April and July (Benson et al , 2007; Heublein et al , 2009). In short, these suggest that temperature is probably a major environmental cue triggering migration of pre‐spawning adult A. sinensis leaving the sea and entering their natal river.…”

The green sturgeon and its environment: past, present, and future

“…The authors detail a manual tracking study of sub-adult and adult fish in the San Francisco Bay Estuary, California, and report that, although the fish tended to occupy the shallower parts of the estuary, sturgeon were apparently not limited by the broad range of environmental conditions in the region, making lengthy directional movements across large gradients. Next, Benson et al (2007) present the results of a three-year study of spawning migration on the Klamath River, California. Their findings agree with those of Erickson et al (2002) on the Rogue River, and indicate that the species migrates up-river in the spring, and that most of the fish remain in the river after spawning, staying in deep, low-velocity pools before out-migrating with the advent of the first winter storms.…”

Downstream migration patterns of one-year-old hatchery-reared European sturgeon (Acipenser sturio)

“…Among anadromous sturgeons, migration has mainly been studied on adults to document reproduction migrations (Benson et al, 2007;Heublein et al, 2009) and marine migration (Edwards et al, 2007;Lindley et al, 2008;Ross et al, 2009). Studies on juvenile in the field have mainly concerned large juveniles (above 60 cm long or greater than 2 years of age) such as the Gulf sturgeon (Acipenser oxyrinchus desotoi) (Harris et al, 2005;Sulak et al, 2009), the green sturgeon (Acipenser medirostris) (Lindley et al, 2011) or the white sturgeon (Acipenser transmontanus) (Parsley et al, 2008).…”