Month: July 2015

[Publication] Growth and mortality in coastal populations of Winter Flounder: implications for recovery of a depleted population

This study by Yencho et al. examined growth, mortality, and settlement distributions of juvenile Winter Flounder Pseudopleuronectes americanus in two bays of Long Island, New York, to better understand localized population dynamics of a species experiencing a protracted population decline. They found that settlement distributions had multiple peaks (cohorts) occurring between March and late July in 2007 and between February and May in 2008. Otolith-based growth rate was significantly higher for Port Jefferson Harbor during 2007 than for all other year × location combinations. Together with previous research the finding of multiple spawning cohorts in Long Island Winter Flounder suggests a degree of isolation, and local management will be needed to support healthy populations.
Winter flounder

Yencho, M.A, Jordaan, A., Cerrato, R.M., Baumann, H., and Frisk, M.G. (2015) Growth and mortality in coastal populations of Winter Flounder: implications for recovery of a depleted population.
Marine and Coastal Fisheries 7: 246-259.

[Presentation] Additive & synergistic effects of concurrent acidification and hypoxia on early life stages of three coastal forage fish

39th Annual Larval Fish Conference, Vienna (Austria) 16 July 2015; American Fisheries Society Annual Meeting, Portland (OR), 19 August 2015

AFS Portland
Baumann et al AFS LFC talk
H. Baumann presented the Master thesis work of Elizabeth Depasquale about individual and concurrent effects of low pH and low oxygen conditions on larval forage fish species at two international conferences. The talk highlighted the novel findings of the study, i.e.: (1) that sensitivities to combined stressors are species- and trait-specific, (2), that larval fish overall seem to be less tolerant of low oxygen than low pH condition, but that (3) the combined effects can be additive and even synergistic; hence suggesting that focussing only on hypoxia in urbanized, eutrophied coastal waters may considerably underestimate the negative effects on larval fish. Even though hypoxia and acidification are almost always coupled conditions in marine environments, the empirical database on such multistressor experiments is still very small and thus precludes robust conclusions and generalizations across taxa or ecosystems.

Depasquale, E., Baumann, H., and Gobler, C.J. (2015) Variation in early life stage vulnerability among Northwest Atlantic estuarine forage fish to ocean acidification and low oxygen. Marine Ecology Progress Series 523: 145–156