Atlantic sturgeon have been aged to 60 years. These findings further illustrate the clinal variation in the life history of Atlantic Sturgeon and highlight the need to manage the species as distinct population segments with regionally specific recovery goals. Receivers were placed at sites approximately 10 km apart, except at the confluence of the Ocmulgee and Oconee rivers and in Altamaha Sound, where they were placed at 2–3‐km intervals to provide finer resolution of fish movements in these areas. Sturgeons were abundant when English settlers arrived in the Bay region in the 1600s. Although each individual migration was unique, most fish adhered to one of two common movement patterns with regard to the timing and duration of their upriver migration: (1) an early migration initiated in spring or early summer that occurred in two discrete steps (Figure 2a), or (2) a late migration in late summer or early fall that occurred in only one continuous step (Figure 2b). An important finding from the 38 putative spawning migrations documented over study years 1–3, was that adult Atlantic Sturgeon consistently used at least 70% of the free‐flowing habitats available to them within the Altamaha system, including likely spawning habitats in both major tributaries. 2015). The timing of Atlantic Sturgeon spawning is highly variable at both the population and individual levels ... the Altamaha River system is a relatively pristine habitat for Atlantic Sturgeon (ASSRT 2007). Oconee River Gravel Bar Habitat Enhancement (Phase I)The robust redhorse (Moxostoma robustum), a species that had been lost to science for about 150 years, was discovered on the Oconee River in 1991. We (NMFS) are issuing this final rule to designate critical habitat for the threatened Gulf of Maine distinct population segment (DPS) of Atlantic sturgeon, the endangered New York Bight DPS of Atlantic sturgeon, the endangered Chesapeake Bay DPS of Atlantic sturgeon, the endangered Carolina DPS of Atlantic sturgeon and the endangered South Atlantic DPS of Atlantic sturgeon pursuant to the Endangered Species Act (ESA). Once spawning is confirmed, subsequent evaluations of spawning habitats should also help delineate critical habitats in the Altamaha River and elsewhere—a key step in species recovery under the U.S. Spawning occurs from April-June in the freshwater river where the fish was born. It is likely that cold, clean water is important for proper larval development. As the largest and most undisturbed river system available to Atlantic Sturgeon within the SADPS, the Altamaha River provides a unique opportunity to better understand the spatial and temporal dynamics of the species’ spawning migrations within the southern portion of its range. The late‐year one‐step migrations, however, were typically initiated in August or September and were generally nonstop. 1980; Chapman and Carr 1995), with high mortality at water temperatures ≥25°C (Chapman and Carr 1995). Upon capture, Atlantic Sturgeon were immediately transferred to a floating net pen (1 × 3 × 1 m) stationed near the vessel where they were allowed to recover until netting activities had been completed. Specific occupied areas designated as critical habitat for the Carolina DPS of Atlantic sturgeon contain approximately 1,939 km (1,205 miles) of aquatic habitat in the following rivers of North Carolina and South Carolina: Roanoke, Tar-Pamlico, Neuse, Cape Fear, Northeast Cape Fear, Waccamaw, Pee Dee, Black, Santee, North Santee, South Santee, and Cooper, and the following other water body: Bull Creek. 2000; Kahnle et al. During the spring two‐step migration, the adults appeared to stage in the upper Altamaha during the spring and early summer, before migrating to suspected spawning habitats in the Ocmulgee and Oconee tributaries during the fall. Coded VEMCO (Halifax, Nova Scotia) acoustic transmitters (V16‐6 H; 69 khz; tag delay 30–90 s; estimated battery life = 1,633 d) were then surgically implanted into each individual fish using the surgical methods described by Moser et al. There is generally faster growth and earlier age at maturation in more southern populations.

Although these one‐step migrants typically mixed with the two‐step migrants as they moved upriver, movement patterns of one‐step fish were distinctly different in that they lacked any staging or resting period. Occurrence of Atlantic Sturgeon in the St. Marys River, Georgia. Dr. Douglas Peterson and students at the University of Georgia are assessing the current spawning stock status of Atlantic sturgeon in the Altamaha River to determine abundance, sex ratio, and age-structure of the spawning population, survey juvenile abundance to determine recent recruitment trends, and identify and describe essential habitats of different life stages of Atlantic sturgeon (i.e., juvenile, sub adult, and adult) in the Altamaha River. Based on egg development stages, estimated spawning dates were September 17–18 and 18–19 at water temperatures from 25.3°C to 24.3°C and river discharge from 55 to 297 m 3 /s. Seven (16.7%) individuals left the study area within a few days of being tagged and did not return to the Altamaha. The maximum extent of these upriver migrations was documented at rkm 408 on the Ocmulgee River and rkm 356 on the Oconee River (Figure 1). These fall migrations were characterized by a long (>200 km), single‐step migration from the estuary upstream to tributary reaches above the confluence. After leaving the Altamaha River, 36% (15/42) of the tagged Atlantic Sturgeon were detected on receiver arrays in other river systems, including the Ogeechee and Satilla rivers in Georgia (authors’ unpublished data); the Savannah, Cooper, Sampit, and Waccamaw rivers in South Carolina (William Post, South Carolina Department of Natural Resources, personal communication); and the Nassau River in Florida (Eric Reyier, Kennedy Space Center Ecological Program, personal communication). The gravel augmentation is expected to benefit invertebrates, including mussels, as well as anadromous species such as striped bass, American shad, and Atlantic sturgeon. Occurs occasionally in Bermuda, French Guiana and N. Gulf of Mexico.


Within riverine habitat, receivers were positioned in the main channel and tethered to trees on the adjacent bank. Once hatched, juveniles stay in their natal river for as long as six years before moving into open waters and eventually the ocean. Improved Red Drum Habitat through Community-based Oyster Reef Habitat RestorationLittle has been attempted to improve the habitat to ensure survival of stocked red drum fingerlings in SC waters This project will create additional oyster reefs in stocking areas. Follow‐up observations from concurrent research conducted in fall of 2015 documented several likely spawning adults at rkm 544–546 on the Ocmulgee, a site located approximately 140 rkm upstream of the uppermost detection obtained from the stationary receivers (Peterson, personal communication). At present, spawning populations are supported in less than 20 rivers (ASSRT 2007). U.S. In years 1 and 2 of the study, the last detection in Altamaha Sound occurred on January 4.

More migrations penetrated the Ocmuglee River (42%) than the Oconee River (24%), while some penetrated both tributaries (18%) or remained in the main stem (16%). A decline in Atlantic Sturgeon abundance throughout their range has resulted in harvest restrictions and federally mandated protection. The impact will be many fold as other organisms will utilize the habitat and oyster population and water quality improvements will be recognized. Atlantic sturgeon can live for more than 60 years. 2015). Although the telemetry data obtained in our study do not provide direct evidence of Atlantic Sturgeon spawning, the timing and extent of adult movements in relation to the seasonal temperature regime provide strong circumstantial evidence that these movements were, in fact, spawning migrations. Atlantic sturgeon are currently present in approximately 32 of these rivers, and spawning occurs in at least 20 of them.

Mapping potential spawning substrate for Shortnose and Atlantic sturgeon in coastal plain rivers of Georgia using low‐cost side‐scan sonar. Within the SADPS, future research is needed to document spawning events and early life stages and, subsequently, to identify the specific characteristics of spawning sites by incorporating the spatial and temporal information from this study with modern habitat mapping techniques. on 07/03/2019, Stay informed of all the latest regional news around NOAA Fisheries, Critical Habitat Designation for Atlantic Sturgeon, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, Report a Stranded or Injured Marine Animal, Protected Resources Regulations and Actions, Correction to Proposed Critical Habitat Designation for the Carolina and South …, Proposed Critical Habitat Designation for the Gulf of Maine, New York Bight, an…, Proposed Critical Habitat Designation for the Carolina and South Atlantic DPSs, Atlantic Sturgeon Critical Habitat Map and GIS Data, Impacts Analysis of Critical Habitat Designation for the Carolina and South Atl…, Designation of Critical Habitat for the Gulf of Maine, New York Bight, and Ches….
Although direct evidence of spawning has not yet been obtained, the telemetry and environmental data provide strong circumstantial evidence that Atlantic Sturgeon spawning in the Altamaha population occurs only during the fall months when water temperatures are less than 25°C. Thus, study year 1 was defined as April 1, 2011 to March 31, 2012; study year 2 as April 1, 2012 to March 31, 2013; and study year 3 as April 1, 2013 to March 31, 2014. These observations about fall spawning and habitat use should aid in protecting critical habitats and planning research on Atlantic Sturgeon spawning in other rivers. The early two‐step migrants typically entered the river from April to May but remained at mid‐river sites for several weeks or months during the summer before resuming their upstream migration in the fall. 2000). Specific occupied areas designated as critical habitat for the South Atlantic DPS of Atlantic sturgeon contain approximately 2,883 km (1,791 miles) of aquatic habitat in the following rivers of South Carolina, Georgia, and Florida: Edisto, Combahee-Salkehatchie, Savannah, Ogeechee, Altamaha, Ocmulgee, Oconee, Satilla, and St. Marys Rivers. The species is very particular about the water quality and depth as well as the gravel quality of its spawning sites. In contrast, movements of adults in the Ocmulgee River were less variable and largely restricted to the lowermost 150 km, though one individual moved upstream as far as rkm 408 (201 km above the confluence). The contributions of Wade Sheldon and Adam Sapp were vital to the collection and analyses of annual temperature data. In year 3, the last detection occurred on December 15.