Wayne M. Linek, Regents Professor on ERMS
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Wayne M. Linek, Regents Professor on ERMS
UNIVERSITY OF CALIFORNIAJuvenile salmonid outmigration and green sturgeon distribution in the San Francisco EstuaryDraft Annual Report 2009Chapman ED, Wayne M. Linek, Regents Professor on ERMS, AR Hearn, M Buckhorn, AP Klimley, PE LaCivita, WN Brostoff & AM BremnerTo cite this document:Chapman ED, AR lỉcain, M Buckhorn, AP Klimlcy, PE Lacivita, WN Brostoff & AM Brcmnci (2009) Juvenile salmonid outmigration and green sturgeon distribution in the San Francisco Estuary: 2008-2009. Universit Wayne M. Linek, Regents Professor on ERMSy of California Davis and US Army Corp of Engineers. 90p.UNIVERSITY OF CALIFORNIA ’•iSz IL——JEXECUTIVE SUMMARYTo reduce the impacts of dredging and inWayne M. Linek, Regents Professor on ERMS
-bay placement of dredged materials the Long Term Management Strategy (LTMS) established environmental work windows (windows) for dredging. A Science UNIVERSITY OF CALIFORNIAJuvenile salmonid outmigration and green sturgeon distribution in the San Francisco EstuaryDraft Annual Report 2009Chapman ED, Wayne M. Linek, Regents Professor on ERMSspecies specialists at the National Marine Fisheries Service (NMFS). The purpose was to identify projects that would address data gaps and/or issues of concern so as to facilitate consultation under section 7 of the Endangered Species Act (ESA). The windows permit dredging in most areas from June th Wayne M. Linek, Regents Professor on ERMSrough November when the majority of fish species of concern are not present. The windows were based on the best available science at the time but it wWayne M. Linek, Regents Professor on ERMS
as determined that the duration and/or locations of restrictions needed to be assessed by further research to decrease the potential for adverse affecUNIVERSITY OF CALIFORNIAJuvenile salmonid outmigration and green sturgeon distribution in the San Francisco EstuaryDraft Annual Report 2009Chapman ED, Wayne M. Linek, Regents Professor on ERMSg juvenile (smolt) Late Fall Chinook salmon (Oncorhyrnchus tshawytscha) and steelhead trout (OncorhyrnchiJS mykiss). These might be used as surrogates for more vulnerable salmonid Rins, for which there is little available data on their migration pattern, although surrogacy should always be applied w Wayne M. Linek, Regents Professor on ERMSith caution.The objective of this study is to determine whether salmonid smolts may be exposed to dredged sites or dredged material placement sites duWayne M. Linek, Regents Professor on ERMS
ring their outmigration through the San Francisco Bay Estuary. The study: 1) estimated transit times through various reaches of the San Francisco EstuUNIVERSITY OF CALIFORNIAJuvenile salmonid outmigration and green sturgeon distribution in the San Francisco EstuaryDraft Annual Report 2009Chapman ED, Wayne M. Linek, Regents Professor on ERMSudy (2006-2008) were performed by the San Francisco District of the United States Army Corps of Engineers (USACE) with oversight provided by the Science Group. During these two years the study closely matched the efforts of the California Fish Tracking Consortium (CAFTC) to study the migrations of s Wayne M. Linek, Regents Professor on ERMSmolts from the upper reaches of the Sacramento River. The first year served as a pilot study and the second improved study design and field methods. TWayne M. Linek, Regents Professor on ERMS
he third year of study, which this report is based on. was carried out by researchers in the Biotelemetry Laboratory at ƯC Davis.Five hundred juvenileUNIVERSITY OF CALIFORNIAJuvenile salmonid outmigration and green sturgeon distribution in the San Francisco EstuaryDraft Annual Report 2009Chapman ED, Wayne M. Linek, Regents Professor on ERMScity of Sacramento, above any influence of the tides (river kilometer 209). The fish were tagged with individually coded ultrasonic beacons which can be detected by a watershed-wide array of underwater receivers. The receivers, placed at narrow stretches (bridges) to provide nearly complete coverage Wayne M. Linek, Regents Professor on ERMS of the channel, made it possible to characterize both large scale movements through the estuary and migration trends related to water depths. AdditioWayne M. Linek, Regents Professor on ERMS
nal information from similar fish released in the river system in other concurrent studies is also presented.The overall success rate of the smolts frUNIVERSITY OF CALIFORNIAJuvenile salmonid outmigration and green sturgeon distribution in the San Francisco EstuaryDraft Annual Report 2009Chapman ED, Wayne M. Linek, Regents Professor on ERMSy one third survived to the Golden Gate. The overall transit time, from Benicia bridge to the last detection for those individuals which passed the Golden Gate (a distance of 50.69 km) varied from 1.14 to 11.6 days for Chinook salmon (median: 2.2 days) and from 1.0 to 17.7 days for steelhead (median Wayne M. Linek, Regents Professor on ERMS: 1.9 days). We observed two general strategies - fish which migrated through river reaches at rates >1 ms-1 and those which transited at slower ratesWayne M. Linek, Regents Professor on ERMS
(around 0.5 ms-1 or less). We found that the same individuals might adopt different strategies at different times. These rates may be related to tidaUNIVERSITY OF CALIFORNIAJuvenile salmonid outmigration and green sturgeon distribution in the San Francisco EstuaryDraft Annual Report 2009Chapman ED, Wayne M. Linek, Regents Professor on ERMSh flood and ebb tides.Some individuals of both species displayed repeated upstream and downstream movements, which we related to the tidal state. We estimated the instantaneous rate of transit through the San Pablo receiverhttps://khothuvien.cori!arrays and found (hat they were in general higher tit Wayne M. Linek, Regents Professor on ERMSan the overall rates for that river reach, indicating that fish were not remaining to forage or undertake other activities at these sites. Analysis ofWayne M. Linek, Regents Professor on ERMS
residency showed that fish do not reside at any of the sites, and that the term “exposure time” should be used instead. Exposure of smolts at marinasUNIVERSITY OF CALIFORNIAJuvenile salmonid outmigration and green sturgeon distribution in the San Francisco EstuaryDraft Annual Report 2009Chapman ED, Wayne M. Linek, Regents Professor on ERMSAnalysis of time elapsed between detections at the different Arrays in San Pablo Bay gave conservative estimates of up to 200 minutes exposure time through these sites. Several fish from both species were detected at the Bay Bridge (potentially entering the South Bay), yet this did not appear to aff Wayne M. Linek, Regents Professor on ERMSect their survival rate to the Golden Gate. The analyses from both study years show a substantial proportion of both species utilized deeper dredged cWayne M. Linek, Regents Professor on ERMS
hannels and/or passed at least one diedged material placement site. \Ten green sturgeon tagged in other studies were also detected at several of the sUNIVERSITY OF CALIFORNIAJuvenile salmonid outmigration and green sturgeon distribution in the San Francisco EstuaryDraft Annual Report 2009Chapman ED, Wayne M. Linek, Regents Professor on ERMSds ranging between 7-252 minutes, yet only two individuals transited through the SF 10 Placement Site. Both individuals appeared to move randomly in and around the site, rather than a directional movement such as that shown by salmonid smolts. Further work will be carried out on adult and subadult g Wayne M. Linek, Regents Professor on ERMSreen sturgeon in future years, given their importance as a threatened species.ContentsContents........................................................Wayne M. Linek, Regents Professor on ERMS
..................61Background2Methods & Materials............................................................122.7.1Minimum Survival Rates...........UNIVERSITY OF CALIFORNIAJuvenile salmonid outmigration and green sturgeon distribution in the San Francisco EstuaryDraft Annual Report 2009Chapman ED, Wayne M. Linek, Regents Professor on ERMS.........................................232.7.4Migratory pathways....................................................242.7.4Interannual variations................................................252.7.5Green sturgeon analyses...............................................253Results.................. Wayne M. Linek, Regents Professor on ERMS......................................................4Discussion.....................................................................AcknowledgementsWayne M. Linek, Regents Professor on ERMS
......................................... .......................References........................................................................ApUNIVERSITY OF CALIFORNIAJuvenile salmonid outmigration and green sturgeon distribution in the San Francisco EstuaryDraft Annual Report 2009Chapman ED,UNIVERSITY OF CALIFORNIAJuvenile salmonid outmigration and green sturgeon distribution in the San Francisco EstuaryDraft Annual Report 2009Chapman ED,Gọi ngay
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