Winter coastal movement of Gulf of Mexico sturgeon throughout northwest Florida and southeast Alabama

Abstract

Summary In order to characterize distribution of Gulf of Mexico sturgeon in nearshore Gulf of Mexico (GOM) and compare distributions prior to and after hurricane activity, 187 Gulf sturgeon (Acipenser oxyrinchus desotoi) were tagged with acoustic transmitters in Ochlockonee, Apalachicola, Brothers, Choctawhatchee, Yellow, Blackwater and Escambia rivers to monitor marine movement along the GOM coastline from Florida (FL) to Alabama (AL). Nine juveniles (79–86 cm fork length, 3.4–5.2 kg), 22 sub‐adults (91–126 cm fork length, 4.5–17.1 kg) and 156 adults (130–210 cm fork length, 14.9–75.2 kg) were tagged between 2003 and 2005 and acoustically monitored each year between January and April, 2004–2008. Of the 187 tagged Gulf sturgeon, 72 adults, one sub‐adult and no juveniles were relocated in the GOM throughout the entire duration of monitoring between 2004 and 2008. Fish were relocated on average 1.5 km from shore in two very important foraging and over wintering areas, one of which is not currently protected under the critical habitat designation: Site A located geographically between Pensacola, FL and Gulf Shores, AL and Site B located between Mexico Beach, FL and Panama City Beach, FL. Sediment studies conducted concluded that substrate at Site A consisted of fine sand, shell and areas of silty mud and substrate at Site B consisted of shell hash and fine sand. Macro invertebrates, such as polychaetes: Hobsonia florida and Mediomastus ambiseta and mollusk: Ervillia concentric, all typical to the Gulf sturgeon diet, were present at both sites. Forty‐three tagged adult Gulf sturgeon were relocated at Site A and 27 adults and one sub‐adult were relocated at Site B, with two additional fish located in other areas. Individual fish movement in one direction ranged from 10 to 315 km each year. Several fish exited one river, over wintered in the GOM, and entered a different river. Identification of new, frequently used Gulf sturgeon habitat (Site A), outside of federally protected critical habitat, provided vital information that will aid in the future protection of coastal areas that support Gulf sturgeon during the winter and help with recovery efforts of the species.

Macrobenthic prey and physical habitat characteristics in a western Gulf sturgeon population: differential estuarine habitat use patterns

“…Moreover, quantifying benthic resource distribution coupled with sediment characteristics are surrogate approaches used to identify primary sturgeon foraging areas (Fox et al 2002, Brooks & Sulak 2005, Harris et al 2005, Nellis et al 2007, Ross et al 2009). These data suggest that Gulf sturgeon, like most sturgeon, are opportunistic benthic foragers (Huff 1975, Miller 2004, Vecsei & Peterson 2004, Parauka et al 2011) as Breder (1929 showed in his detailed description of sturgeon foraging behavior. Sturgeon use barbels, snout and head electroreceptors, their specialized tubular mouth, and suction feeding (Miller 2004, Vecsei & Peterson 2004) to obtain prey from sediments.…”

“…Beta-dyne ® impregnated petroleum jelly was used on all tagging wounds. Captured Gulf sturgeon were categorized as adult (>125.0 cm FL), sub-adult (89.1− 125.0 cm FL), and juvenile (30.4− 89.0 cm FL; Parauka et al 2011). …”

“…It is clear, however, that diets vary ontogenetically (Huff 1975, Mason & Clugston 1993 across their range because of zoogeographic differences in prey distribution (Parauka et al 2011), as well as water depth and sediment composition (Fox et al 2002, Harris et al 2005. Moreover, quantifying benthic resource distribution coupled with sediment characteristics are surrogate approaches used to identify primary sturgeon foraging areas (Fox et al 2002, Brooks & Sulak 2005, Harris et al 2005, Nellis et al 2007, Ross et al 2009).…”

Natural stranding of Atlantic sturgeon (Acipenser oxyrinchus Mitchill, 1815) in Scot's Bay, Bay of Fundy, Nova Scotia, from populations of concern in the United States and Canada

“…Most records of sturgeon stranding events occur in river systems, due to either natural seasonal water level changes, or changes caused by dams and flood diversions (Thomas et al., ). In 2004, Hurricane Ivan caused the stranding of Gulf Sturgeon in the Escambia River, Florida and nearby bays (Parauka et al., ). This, toether with our observations, suggests that Atlantic sturgeon and their close relatives may be naturally susceptible to stranding in various habitats.…”

Estimating Sturgeon Abundance in the Carolinas Using Side‐Scan Sonar

“…Based on telemetry studies (Erickson et al 2011;Parauka et al 2011;Oliver et al 2013), sturgeon are known to move between river systems. Therefore, a sturgeon detected in a given river system may not belong to that river's reproductive population.…”