Evaluating Atlantic and Shortnose Sturgeon Behavior Related to the Savannah Harbor Expansion Project

Transcription

1 Evaluating Atlantic and Shortnose Sturgeon Behavior Related to the Savannah Harbor Expansion Project Cooperative Agreement Numbers W912EP & W912EP Annual Report FY 2014 (November 1, 2013 October 31, 2014) Submitted by Bill Post, Chad Holbrook, Corbett Norwood, and Jeremy Grigsby South Carolina Department of Natural Resources 217 Fort Johnson Rd. Charleston, SC Submitted to: U.S. Army Corps of Engineers (USACE) Planning Division 100 W. Oglethorpe Avenue Savannah, GA 3140

2 Table of Contents Savannah Harbor Expansion Project (SHEP)...2 SHEP Estuarine Study... 2 Introduction... 2 Material and Methods... 2 Results... 4 Discussion... 7 SHEP New Savannah Bluff Lock and Dam (NSBL&D) Study... 8 Introduction... 8 Material and Methods... 8 Results Discussion Literature Cited Appendix 1. Project Pictures Appendix 2. Water quality data Appendix 3. Adult Atlantic and shortnose sturgeon spawning movement

3 Savannah Harbor Expansion Project Estuarine Study Introduction The Atlantic sturgeon (Acipenser oxyrinchus) and shortnose sturgeon (Acipenser brevirostrum) inhabit many rivers of the U.S. Atlantic coast, including many South Carolina Rivers. As part of the Savannah Harbor Expansion Project, the U.S. Army Corps of Engineers (USACE), Savannah District committed to monitor the distribution of sturgeon in the Savannah River Estuary. The South Carolina Department of Natural Resources (SCDNR) was selected to conduct a telemetry study to collect movement data for both species of sturgeon and report finding to the USACE. The USACE has committed to monitoring distribution of sturgeon in the estuary for one year preconstruction, during construction (duration of four years), and post-construction years. This will be accomplished through the use of telemetry and sonic transmitters and will identify seasonal distribution and migration patterns. Material and Methods In year one of the study, the proposed goals were for SCDNR to capture and insert 20 sonic transmitters into sturgeon (10 Atlantic sturgeon and 10 shortnose sturgeon) in the Savannah River Estuary. The goal was a 50/50 split between adult and juvenile shortnose sturgeon and sub-adult and juvenile Atlantic sturgeon. Shortnose sturgeon juveniles were those with fork lengths (FL) less than 600mm and shortnose sturgeon adults were those with a FL greater than 600mm. Atlantic sturgeon juveniles were those fish with FL less than 800mm and sub-adults were those with FL greater than 800mm but 2

4 less than 1200mm. Two sizes of transmitter were used in the study, depending on the transmitter/fish size ratio. Vemco V9 tags were inserted into juveniles and V16 tags were inserted into adults/sub-adult fish. Theses transmitters have an estimated life of 387 days and 4 years, respectively. Sturgeon were captured by deploying 92m mono-filament sinking set gill nets. In most cases, these gill nets were deployed and set for no longer than 60 minutes (Appendix 1). Oxygen was used and monitored in holding tank while fish were tagged and life history data was recorded. Transmitters were surgically implanted in the abdominal cavity of Atlantic and shortnose sturgeon following standard surgery protocols. During summer months, sampling ceased due to elevated water temperature and requirements of the Section 10 Endangered Species Permit. Additionally, an array of 25 fixed Vemco VR2W receivers were deployed from the mouth of the river through the Front, Middle, and Back Savannah River. Receivers were deployed closer in proximity to the King Island Turn Basin and the entrance to the Middle River, as this has previously been determined important habitat for sturgeon (Collins et al. 2002) (Figure 1). When accessible, receivers were downloaded every few months at normal water levels and all downloaded files were imported into Vemco VUE software for analysis. Additionally, manual tracking was performed monthly with a Vemco VR-100 receiver to better characterize acceptable habitat for Atlantic and shortnose sturgeon in the Savannah River Estuary and to find fish that might otherwise be lost in between receiver locations. Tracking efforts consisted of using the VR-100 and hydrophone every 0.3 kilometers which began on the Savannah River at Mill Stone Landing around river kilometer (rkm 54), proceeded downriver to Abercorn Creek, and continued down the Front River to the King Island Turn Basin, with tracking events 3

5 occurring in the Middle and Back Rivers. If a fish was detected, the latitude, longitude, temperature, salinity and oxygen profile at 1-m depth intervals was taken at each location of detected sturgeon (Appendix 2). Figure1. Vemco receiver locations within proximity to the King Island Turn Basin. Results Twenty-nine Atlantic sturgeon were captured and thirteen (8 sub-adult and 5 juveniles) were surgically implanted with transmitters. Sixteen shortnose sturgeon were captured and fourteen (7 adult and 7 juveniles) were surgically implanted with transmitters 4

6 (Table1). Life history information (length, weight, etc.) were recorded for all captured sturgeon and all transmitted fish were detected by at least one receiver. Table1. Sturgeon capture data for the Savannah River Estuary SHEP project. Date River Species PIT FL (mm) TL (mm) WT (g) Genetics Transmitter Code 11/5/2013 Savannah A. brev (juvenile) 4A0E18502E MS /5/2013 Savannah A. oxy (juvenile) 4A MS /7/2013 Savannah A. oxy (juvenile) 4A0E00482D MS /7/2013 Savannah A. oxy (juvenile) 4A0D4F704C MS /13/2013 Savannah A. oxy (juvenile) 4A3F2A4F MS /14/2013 Savannah A. oxy (juvenile) 4A0D5B5B7E MS /14/2013 Savannah A. oxy (juvenile) 4A0E1D MS /14/2013 Savannah A. oxy (juvenile) 4A0E142F3A MS /14/2013 Savannah A. oxy (sub/adult) 4A0E260F MS /21/2013 Savannah A. brev (juvenile) 0A13675E MS /21/2013 Savannah A. brev (juvenile) 0A13675E MS /22/2013 Savannah A. brev (juvenile) 0A13675A MS /5/2013 Savannah A. oxy (sub/adult) 0A13675A MS /11/2013 Savannah A. brev (juvenile) 0A13674B1B MS /11/2013 Savannah A. brev (juvenile) 0A13674B MS /21/2014 Savannah A. brev (juvenile) 4A0E16614C MS /21/2014 Savannah A. brev (adult) 4A0E MS /21/2014 Savannah A. brev (juvenile) 4A0D570F MS /28/2014 Savannah A. brev (adult) 0A13675D MS /28/2014 Savannah A. brev (adult) 0A13675D3C MS /28/2014 Savannah A. oxy (sub/adult) 0A13675D MS /7/2014 Savannah A. brev (adult) 0A13092F MS /7/2014 Savannah A. brev (adult) 0A13675D6C MS /7/2014 Savannah A. brev (adult) 0A13675D5A MS /14/2014 Savannah A. brev (adult) 0A13675D7D MS /14/2014 Savannah A. oxy (sub/adult) 0A13675D2D MS /21/2014 Savannah A. oxy (sub/adult) 0A13092F MS As was observed in previous studies, shortnose sturgeon were detected in the middle river mouth, and front river (rkm 27-36) during the winter and spring months (Figure 2). Then, when the water temperature began to increase in summer months, most of the transmitted 5

7 shortnose migrated to the front river (rkm 38 44) near Abercorn Creek. Fish remained in the front river ~rkm 44 until temperatures decreased, then fish returned to the Middle River mouth area. Three adult shortnose sturgeon made presumed spawning runs in March to potential spawning habitat at (rkm 109, 162, 191.5; respectively). Figure 2. Location of shortnose sturgeon in the winter and spring months. Atlantic Sturgeon were detected in the Middle River mouth area during the winter and spring months until the water temperature began to increase in April and May. Six Atlantic sturgeon left the Savannah River system and were later detected in other coastal rivers (Cooper River, Charleston Harbor, Winyah Bay System, Little River, Ossabaw 6

8 Sound, and Santee River). In addition to receiver downloads, manual tracking occurred every month during year one of the study. One Atlantic and six shortnose sturgeon that were transmitted during this study and six Atlantic and 18 shortnose from a previous telemetry study were detected during these events. Location and water quality data were recorded for each fish and were entered in the database. Manual tracking efforts are scheduled to continue throughout the study. Discussion During this year, the SCDNR was successful in all objectives in the USACE statement of work for this study. Twenty sturgeon (both species and both life stages) were captured and received transmitters. All purchased receivers were deployed within the study area and downloaded every few months. Additionally, manual tracking efforts were carried out as specified in the statement of work (monthly or quarterly). Analysis of collected sturgeon detections concluded that both Atlantic and shortnose sturgeon use the Middle and Front Savannah River (rkm 27-35) during the winter and early spring months. Most Atlantic sturgeon exit the river system in April - May. There was no notable difference between juvenile and sub/adult shortnose sturgeon movement in the estuary, and adult movement differed from that of the sub-adult Atlantic sturgeon, with some individuals undertaking migrations potential up-river spawning habitat in March. To further illustrate this point, spawning migration data from a previous multi-year telemetry study for both shortnose and Atlantic sturgeon are provided in Appendix 3. This figure is provided for informational purpose only and is not intended to be included as any part of this scope of work. Since these are multi-year transmitters, future scheduled work will help identify requirement habitat for both species of sturgeon within the study area. 7

9 SHEP New Savannah Bluff Lock and Dam Study Introduction As part of the Savannah Harbor Expansion Project, the U.S. Army Corps of Engineers, Savannah District (USACE) committed to monitor sturgeon and anadromous fish at the New Savannah Bluff Lock and Dam (NSBL&D) and an off-channel rock ramp bypass that is proposed to be constructed around NSBL&D near Augusta, GA. The South Carolina Department of Natural Resources (SCDNR) is conducting a telemetry study to collect information concerning movement of fish around the structure. Materials and Methods The Savannah River NSBL&D is located at rkm 302 just below the Augusta Shoals. In order to assess behavior of fish upstream and downstream of the structure, Vemco VR2W receivers were placed above and below the NSBL&D and future site of the rock arch ramp bypass. To address those fish that pass above, six receivers were placed just above the NSBL&D to the upper Augusta Shoals area, with the furthest being 32 rkm above the dam (Figure3). Below the dam, there are fifty-four receivers located from just below the NSBL&D to those that are deployed in the estuary, providing full coverage of the river from rkm rkm 0. Receivers were downloaded every few months, when accessible at normal water levels, and all files were downloaded and imported in to Vemco VUE software for analysis. 8

10 Figure 3. Receivers located above New Savannah Bluff Lock and Dam. In an attempt to capture target specimens, drift gillnets, set gillnets, and boat electrofishing was used. A 68.5 meter drift gill net with 12.7 cm stretch mesh was used when water levels exceeded flood conditions. All other times, set nets that were 92 meters in length with either 12.7 or 17.8 cm stretch mesh. These nets were set for no longer than 60 minutes and sampling ceased in summer months when water temperatures were above 28 degrees. Additionally, to capture other fish representative of those that might use the new rock arch ramp bypass, boat electrofishing equipment was used. 9

11 Transmitters (Vemco V9) were implanted gastrically in any captured American shad and Vemco V16 transmitters were surgically implanted in the abdominal cavity of any striped bass, hybrid bass, or sturgeon. The V9 and V16 have an estimated battery life of 187 days and 4 years respectively. Results Sampling occurred in April 2014 at the NSBL&D site (rkm 300) using both drift and set gill nets for sturgeon. No sturgeon were captured. During the same month, electrofishing sampling at the same site in order to capture other representative fish occurred (Figure 4). Twelve American shad (Alosa sapidissima) were captured, measured, and gastrically implanted with V9 sonic transmitters, and two striped bass (Morone saxatilis) and a hybrid bass (Morone chrysops x Morone saxatilis) were surgically implanted with V16 transmitters (Table 2). 10

12 Figure 4. Sampling area below New Savannah Bluff Lock and Dam. 11

13 Table 2. American shad and striped bass transmitted at NSBL&D. Date River Species Sex External FL (mm) TL (mm) Transmitter Code 4/18/2014 Savannah A. sap F F /18/2014 Savannah A. sap M F /18/2014 Savannah A. sap F F /18/2014 Savannah A. sap F F /18/2014 Savannah A. sap M F /18/2014 Savannah A. sap M F /18/2014 Savannah A. sap F F /18/2014 Savannah A. sap M F /18/2014 Savannah A. sap F F /18/2014 Savannah A. sap M F /18/2014 Savannah A. sap F F /18/2014 Savannah A. sap M F /18/2014 Savannah M. sax? F /18/2014 Savannah M. sax? F All fish captured and transmitted at NSBL&D were detected on at least one receiver. Ten transmitted American shad stayed below the NSBL&D at (rkm 301) and two (male and female) were detected above the NSBL&D at (rkm 321). The striped and hybrid bass were detected on multiple receivers, with the striped bass migrating down to (rkm 34) and the hybrid bass detected as low as (rkm 214). Additionally, three striped bass, that were tagged in the estuary in cooperation with the Georgia DNR, were detected just below NSBL&B from February May. One migrated down river and the other two stayed within 30 rkm of NSBL&D throughout the summer season. Generally, American shad found in southern river systems below Cape Hatteras, NC are thought to be semelparous, meaning they spawn once and die, so it is very likely American shad transmitted at NSBL&D during this study also die after spawning. Careful analysis of receiver detections were performed in order to confirm that receivers 12

14 tracking American shad were not detecting the transmitter of a deceased fish at the NSBL&D. Discussion During this year, the SCDNR was successful in all objectives in the USACE statement of work for this study. All receivers were deployed above and below the NSBL&D for the pre-construction period. Although no sturgeon were transmitted in year one at NSBL&D, future spring and fall sampling should increase the probability of tagging adult Atlantic sturgeon. American shad, striped bass, and hybrid bass were successfully transmitted, and receiver detections showed extensive movement and the presence of some shad above NSBL&D. This is evidence, that in at least some years, shad are passed upstream via the navigation lock or during extreme high flows through the structure itself. The transmitted striped/hybrid bass have a long-lived transmitter so future downloads should provide additional information concerning migration and spawning patterns in the Savannah River. 13

15 Literature Cited Collins, M. R., W. C. Post, D. C. Russ, and T.I.J. Smith Habitat use and movements of juvenile shortnose sturgeon in the Savannah River, Georgia - South Carolina. Transactions of the American Fisheries Society 131:

16 Appendix 1: 15

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20 Appendix 2: Date River Location Receiver Temperature Salinity Dissolved Oxygen 09-Jan-14 Savannah RM Jan-14 Savannah RM Jan-14 Savannah RM Jan-14 Savannah RM Jan-14 Savannah RM Jan-14 Savannah MR RM Jan-14 Savannah MR RM Jan-14 Savannah RM Jan-14 Savannah Sav Jetty Mar-14 Savannah MR RM Mar-14 Savannah RM Mar-14 Savannah RM Mar-14 Savannah RM Mar-14 Savannah RM Mar-14 Savannah RM Mar-14 Savannah SAV Jetty Mar-14 Savannah RM Mar-14 Savannah BR RM Mar-14 Savannah RM Mar-14 Savannah BR RM Mar-14 Savannah MR RM Mar-14 Savannah MR RM Mar-14 Savannah MR RM Mar-14 Savannah MR RM Mar-14 Savannah RM Mar-14 Savannah BR RM Apr-14 Savannah RM Apr-14 Savannah RM Apr-14 Savannah RM Apr-14 Savannah RM May-14 Savannah Sav Jetty May-14 Savannah RM May-14 Savannah RM May-14 Savannah MR RM May-14 Savannah RM May-14 Savannah RM May-14 Savannah RM May-14 Savannah RM Jun-14 Savannah BR RM

21 Date River Location Receiver Temperature Salinity Dissolved Oxygen 05-Jun-14 Savannah BR RM Jun-14 Savannah MR RM Jun-14 Savannah RM Jun-14 Savannah BR RM Jun-14 Savannah MR RM Jun-14 Savannah Abercorn RM Jun-14 Savannah RM Jun-14 Savannah RM Jun-14 Savannah MR RM Jun-14 Savannah Abercorn RM Jun-14 Savannah RM Jun-14 Savannah RM Jun-14 Savannah RM Jun-14 Savannah RM Jun-14 Savannah RM Jun-14 Savannah RM Jun-14 Savannah RM Jun-14 Savannah RM Jun-14 Savannah RM Jun-14 Savannah RM Jun-14 Savannah RM Aug-14 Savannah Abercorn RM Aug-14 Savannah RM Aug-14 Savannah RM Aug-14 Savannah RM Aug-14 Savannah RM Aug-14 Savannah RM Aug-14 Savannah RM Aug-14 Savannah RM Aug-14 Savannah RM Aug-14 Savannah RM Sep-14 Savannah BR RM Sep-14 Savannah BR RM Sep-14 Savannah BR RM Sep-14 Savannah Abercorn RM Sep-14 Savannah MR RM Sep-14 Savannah MR RM