Sixth Annual Long Island Natural History Conference














Restoring Oyster Reefs in Hempstead Bay: Methods, Results and Future directions
James P. Browne, Department of Conservation and Waterways, Town of Hempstead


The natural reef formations of the eastern oyster (Crassostrea virginica) have been lost from most of their range, and the bays of Long Island are no exception.  This loss has not only had economic impacts, but losing this valuable ecosystem engineer implies adverse ecological effects as well. Increased salt marsh erosion is only one possible downside of the loss. Traditional oyster management methods, such as returning loose shell and adding loose or spat-on-shell seed oyster, have a long history of use. Unfortunately, the use of these methods during the long period of decline implies that improvement is needed. We are designing our projects with the idea that successful reef restorations will require new approaches that more closely mimic the original reef structures. To understand our local conditions we installed an array of AquaPurse® cages holding spat, and tracked their growth from 2009 through 2012. We also installed three test reefs under a NYS DEC permit, starting in 2009 and added to them through 2014, positioned to afford wave attenuation for salt marshes. Follow-up measurements have included survival, species inventories, and sediment accumulation. Finally, we have been working with science students from Long Beach High School to explore some aspects of oyster fertilization.

Preliminary student results support the possibility that reef destruction and scattered replacement may have hurt reproduction in unanticipated ways and further contributed to oyster decline. Student projects appear to indicate that tightly packed reefs in spawning reserves may be needed for successful reestablishment and that there may be other unanticipated consequences from over-harvesting. We feel that our method of retaining spat on shell oysters within mesh bags, and binding them on top of additional layers of bagged shell, mimics small natural reefs enough to keep the oysters in the water column, away from bottom effects, and allowing for a more natural vertical orientation of the oysters. We will discuss plans for future work, including shell recycling in conjunction with Adelphi University.