ESR 39:63-76 (2019)  -  DOI: https://doi.org/10.3354/esr00957

ABSTRACT: Atlantic sturgeon Acipenser oxyrinchus oxyrinchus were listed as 5 distinct population segments under the US Endangered Species Act in 2012. At that time, only 2 abundance estimates of the Atlantic sturgeon population were available: one from commercial fisheries landings in the Hudson River ending in 1995 and one from mark-recapture research in the Altamaha River, Georgia, in 2004 and 2005. In 2013, we verified spawning in the York River, Virginia, system and initiated a multiple-year mark-recapture study focusing on spawning-run abundance. We used a Schumacher-Eschmeyer model and Program CAPTURE to produce estimates of annual spawning abundances from 2013 to 2018. The Schumacher-Eschmeyer estimates of spawning-run abundance with 95% confidence intervals from 2013 to 2018 were 75 (31-190), 157 (115-244), 184 (150-238), 222 (137-576), 212 (157-328), and 145 (89-381), respectively. Because Atlantic sturgeon do not spawn every year, the trends in estimates do not suggest a recovering or declining population, but rather variability in proportions of the adult population that return to spawn each year. The estimates produced in Program CAPTURE using M₀ (null), M_t (Chao M_t and Darroch), M_h (Chao M_h and Jackknife), and M_th (Chao M_th) models all produced similarly reliable estimates. The models that consider a behavioral response to initial capture (M_b, M_bh, and M_tb) failed to produce reliable estimates for this data, likely because as an endangered species, the dataset for Atlantic sturgeon was sparse. The Jackknife equation (model M_h) was the most precise every year with reliable accuracy and therefore is recommended.

KEY WORDS: Anadromous · Conservation · Endangered species · Fish · Mark-recapture · Monitoring · Native fish · Population ecology · Population modeling

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Cite this article as: Kahn JE, Hager C, Watterson JC, Mathies N, Hartman KJ (2019) Comparing abundance estimates from closed population mark-recapture models of endangered adult Atlantic sturgeon. Endang Species Res 39:63-76. https://doi.org/10.3354/esr00957 Export citation Share:    Facebook - - linkedIn