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The continued development of effective mark and recapture tools for marine invertebrates is required to better understand fundamental planktonic processes such as larval transport and mortality. Mass chemical marking methods provide researchers with the ability to mark large quantities of individuals at one time with reduced handling stress and costs. Although 3-day-old larvae of Crassostrea virginica (eastern oyster) have been marked with calcein (a fluorochrome dye) and recaptured, pediveligers have not been marked nor has mark retention through metamorphosis been verified. To track mark retention through metamorphosis, 12,000 pediveligers were marked for 24 and 48 h in calcein of 25 and 50 mg [L.sup.-1] concentrations, and mark retention was tracked every 7 days for 4 wk. Results indicated that calcein did not affect initial settlement rates, that the distinct bands on larval shells were visible after metamorphosis, that individuals marked as larvae were positively identified up to 4 wk postsettlement without sacrificing individuals, and that lower calcein concentrations than previously documented were effective. This study demonstrates that calcein is a reliable method for marking C. virginica pediveligers and suggests that relatively low concentrations of calcein can produce marks and could reduce costs and potential harmful effects. KEY WORDS: oyster, larvae, calcein, fluorochrome, Crassostrea virginica, marking, mark and recapture, INTRODUCTION Understanding planktonic dispersal and population connectivity in marine ecosystems remains a fundamental obstacle in the management of many marine organisms (Cowen et al. 2007, Krueck et al. 2017). Discerning [...]

ABSTRACT Understanding the population dynamics and complete life cycle of bivalves is important for effective management of these commercially and ecologically important organisms. Most of the literature and research on [...]

ABSTRACT The eastern oyster, Crassostrea virginica (Gmelin, 1791) has been in decline along the eastern seaboard, and especially in Chesapeake Bay, for decades because of over-harvesting, disease and declines in [...]

The effects of seagrass bed geometry on wave attenuation and suspended sediment transport were investigated using a modified Nearshore Community Model (NearCoM). The model was enhanced to account for cohesive sediment erosion and deposition, sediment transport, combined wave and current shear stresses, and seagrass effects on drag. Expressions for seagrass drag as a function of seagrass shoot density and canopy height were derived from published flume studies of model vegetation. The predicted reduction of volume flux for steady flow through a bed agreed reasonably well with a separate flume study. Predicted wave attenuation qualitatively captured seasonal patterns observed in the field: wave attenuation peaked during the flowering season and decreased as shoot density and canopy height decreased. Model scenarios with idealized bathymetries demonstrated that, when wave orbital velocities and the seagrass canopy interact, increasing seagrass bed width in the direction of wave propagation results in higher wave attenuation, and increasing incoming wave height results in higher relative wave attenuation. The model also predicted lower skin friction, reduced erosion rates, and higher bottom sediment accumulation within and behind the bed. Reduced erosion rates within seagrass beds have been reported, but reductions in stress behind the bed require further studies for verification. Model results suggest that the mechanism of sediment trapping by seagrass beds is more complex than reduced erosion rates alone; it also requires suspended sediment sources outside of the bed and horizontal transport into the bed. [ABSTRACT FROM AUTHOR]