Slide 1

Preliminary analysis (2 cages, 24 clams/cage) showed that the ranking of sites in terms of clam growth over 5 wks in 2013 was: Tuckerton > HC = Sedge > IBSP. Low growth at IBSP in 2013 is attributed to low salinities during early-mid June (minimum = 16, Table 1) approaching the low tolerance limit for hard clams [1]. Clams ceased growing during this period, which coincided with high precipitation (cumulative levels of ~10, compared to 5 in 2012). Harvey Cedars (HC) Sedge Is. (Marine Conservation Zone) Island Beach State Park (IBSP) Tuckerton Cove Little Egg Inlet Barnegat Inlet The optimum temperature range for hard clam growth is ~20 o to 24 o C, with growth rates declining above and below this range [1]. Despite consistently lower temperatures and markedly greater temperature variation at Sedge (up to 16 o C day -1 ) than at other sites ( Tuckerton > IBSP > HC ). Fig. 3: Contribution of Phytoplankton FTGs to Chl a and Clam Soft Tissue Growth Rates- Deployment II 2012 Background Fig. 5: Mean Shell Growth Rates Deployment I 2013 Fig 2: Water Temperatures (daily means) during Deployment I Toms River [1] Grizzle R., V.M. Bricelj, S.E. Shumway. 2001, Physiological ecology of Mercenaria mercenaria, Chapter 8 In: Kraeuter, J. & M. Castagna (eds.). Biology of the Hard Clam. Amsterdam: Elsevier, New York, pp. 305-382. [2] Paerl, H. W., L. M. Valdes, J. L. Pinckney, M. F. Piehler, J. Dyble, P. H. Moisander. 2003. Phytoplankton photopigments as indicators of estuarine and coastal eutrophication. BioScience 53.10: 953 [3] Mahoney and Olsen 2001, Phytoplankton in the Barnegat Bay-Little Egg Harbor system: Species composition and picoplankton bloom development. Journal of Coastal Research 32: 115-143 LE H Fig. 4: Relationship between Picoplankton & Clam Growth (IBSP)