ISSN : 1225-3480
Mass mortalities of farmed shellfish, mostly in summer season, thus named mass summer mortalities, have been a global issue in shellfish aquaculture. The 2013 mass summer mortalities in the confined waters of Goseong Bay, Goseong, Korea were quite a unique and intensive for two farmed species, the Pacific oysters, Crassostrea gigas, and bay scallops, Argopecten irradians. The mortalities were progressive from the bottom of the suspended oysters and caged scallops in the waters, reaching up to 80% for the oyster and 95% for the scallop in about 20 days after the first occurrence, early August, 2013. We monitored a wide range of environmental factors, including water temperature, dissolved oxygen (DO), salinity, turbidity, acidity (pH), organic and inorganic matters, chemical oxygen demand (COD), suspected pathogenic agent, and phytoplankton composition throughout the water column where the two species were suspended or caged. Our survey concluded that the hypoxia or anoxia might be a major cause of the mortalities. Here, we detailed the mortalities and ways to arrive at the conclusion.
Cheney, D.P., MacDonald, B.F., and Elston, R.A. (2000) Summer mortality of Pacific oysters, Crassostrea gigas (Thunberg): initial findings on multiple environmental stressors in Puget Sound, Washington, 1998. Journal of Shellfish Research, 19: 353- 359.
Christine, M.C., and Catriona, K.A. Macleod and Mitchell, I.M. (2003) Effects of shellfish farming on the benthic environment. Aquaculture, 224: 117-140.
Chu, F.L.E., and La Peyre, J.F. (1993) Perkinsus marinus susceptibility and defense-related activities in eastern oysters Crassostrea virginica: temperature effects. Diseases of Aquatic Organisms, 16: 223-234.
Deutsch, C., Brix, H., Ito, T., Frenzel, H., and Thompson, L. (2011) Climate-forced variability of ocean hypoxia. Science, 333: 336-339.
Diaz, R.J., and Rosenberg, R. (1995) Marine benthic hypoxia: a review of its ecological effects and the behavioural responses of benthic macrofauna Oceanogr. Marine Biology Annual Review, 33: 245-303.
Diaz, R.J., and Rosenberg, R. (2008) Spreading dead zones and consequences for marine ecosystems. Science, 321: 926-929.
Gulka, G., Chang, P.W., and Marti, K.A. (1983) Prokaryotic infection associated with a mass mortality of the sea scallop, Placopecten magellanicus. Journal of Fish Diseases, 6: 355-364.
Han, G.D., Zhang, S., Marshall, D.J., Ke, C., and Dong, Y. (2013) Metabolic energy sensors (AMPK and SIRT1), protein carbonylation and cardiac failure as biomarkers of thermal stress in an intertidal limpet: linking energetic allocation with environmental temperature during aerial emersion. Journal of Experimental Biology, 216: 3273-3282.
Ivanina, A.V., Kurochkin, I.O., Leamy, L., and Sokolova, I.M. (2012) Effects of temperature and cadmium exposure on the mitochondria of oysters (Crassostrea virginica) exposed to hypoxia and subsequent reoxygenation. Journal of Experimental Biology, 215: 3142-3154.
Kaiser, M.J., Laing, I., Utting, S.D., and Burnell, G.M. (1998) Environmental impacts of bivalve mariculture. Journal of Shellfish Research, 17: 59-66.
Lacoste, S.A. (2001) Stress and Stress-Induced Neuroendocrine Changes Increase the Susceptibility of Juvenile Oysters (Crassostrea gigas) to Vibrio splendidus. Applied and Environmental Microbiology, 67: 2304-2309.
Moullac, L., Soyez, G.C., Saunier, D., Ansquer, D., Avarre, J.C., and Levy, P. (1998) Effect of hypoxic stress on the immune response and the resistance to vibriosis of the shrimp Penaeus stylirostris. Fish and Shellfish Immunology, 8: 621-629.
Gagnaire, B., Frouin, H., Moreau, K., Thomas-Guyon, H., and Renault T. (2006a) Effects of temperature and salinity on haemocyte activities of the Pacific oyster, Crassostrea gigas (Thunberg). Fish and Shellfish Immunology, 20: 536-547.
Gagnaire, B., Frouin, H., Moreau, K., Thomas-Guyon, H., and Renault, T. (2006b) Pollutant effects on Pacific oyster, Crassostrea gigas (Thunberg), hemocytes: Screening of 23 molecules using flow cytometry. Cell Biology and Toxicology, 22: 1-14.
Garnier, M., Labreuche, Y., Garcia, C., Robert, M., and Nicolas, N.L. (2007) Evidence for the Involvement of Pathogenic Bacteria in Summer Mortalities of the Pacific Oyster Crassostrea gigas Evidence for the Involvement of Pathogenic Bacteria in Summer Mortalities of the Pacific Oyster Crassostrea gigas. Microbial Ecology, 53: 187-196.
Lee, N.S., Hwang, J.Y., Choi, D.L., and Park, M.A. (2010) Survey of Perkinsus olseni infection in Manila clam, Ruditapes philippinarum in 2009 on the west and south coast of Korea using PCR technique. Journal of Fish Pathology, 23: 145-153.
McBryan, T.L., Anttila, T.L., Healy T.M., and Schulte, P.M. (2013) Responses to Temperature and Hypoxia as Interacting Stressors in Fish: Implications for Adaptation to Environmental Change. Integrative and Comparative Biology, 53: 648-659.
Myrand B., and Gaudreault, J. (1995) Summer mortality of blue mussel (Mytilus edulis Linneaus, 1758) in the Magdalen islands (southern gulf of St. Lawrence, Canada). Journal of Shellfish Research, 14: 395-404.
Parsons, G.J., and Dadswell, M.J. (1992) Effect of stocking density on growth, production, and survival of the giant scallop, Placopecten magellanicus, held in intermediate suspension culture in Passamaquoddy Bay, New Brunswick. Aquaculture, 103: 291-309.
Pernet, F., Barret, J., Le Gall, P., Corporeau, C., Degremont, L., Lagarde, F., Pepin, J.F., and Keck, N. (2012) Mass mortalities of Pacific oysters Crassostrea gigas reflect infectious diseases and vary with farming practices in the Mediterranean Thau lagoon, France. Aquaculture Environment Interaction, 2: 215-237.
Portner, HO. (2010) Oxygen- and capacity-limitation of thermal tolerance: a matrix for integrating climate-related stressor effects in marine ecosystems. Journal of Experimental Biology, 213: 881-893.
Rabalais, N.N., Turner, R.E., Diaz, R.J., and Justic, D. (2009) Global change and eutrophication of coastal waters. ICES Journal of Science Marine Science, 66: 1528-1537.
Standard Methods for the Examination of Environment Pollution. (2010) Ministry of Land, Transport and Maritime Affairs, Korea.
Steckbauer, A.C., Duarte, M., Carstensen, J., Vaquer-Sunyer, R., and Conley, D.J. (2011) Ecosystem impacts of hypoxia: thresholds of hypoxia and pathways to recovery. Environmental Research Letters, 6: 1-12.
Thieltges, D.W. (2006) Parasite Induced Summer Mortality in the Cockle Cerastoderma edule by the Trematode Gymnophallus choledochus. Hydrobiologia, 559: 455-461.
Thompson, P.A., and Harrison, P.J. (1992) Effects of monospecific algal diets of varying biochemical composition on the growth and survival of Pacific oyster (Crassostrea gigas) larvae. Marine Biology, 113; 645-654.
Tilman, D., Fargione, J., Wolff, B., D'Antonio, C., Dobson, A., Howarth, R., Schindler, D., Schlesinger, W.H., Simberloff, D., and Swackhamer, D. (2001) Forecasting agriculturally driven global environmental change. Science, 292: 281-284.
Vaquer-Sunyer, R., and Duarte, C.M. (2010) Sulfide exposure accelerates hypoxia-driven mortality. Limnology Oceanography, 55: 1075-1082.
Vaquer-Sunyer, R., and Duarte, C.M. (2008) Thresholds of hypoxia for marine biodiversity. Proceedings of National Academy of Sciences, USA, 105: 15452-15457.
Watt, W.B., and Dean, A.M. (2000) Molecular-functional studies of adaptive genetic variation in prokaryotes and eukaryotes. Annual Review, 34: 593-622.
Xiao, J., Ford, S.E., Yang, H., Zhang, G., Zhang, F., and Guo., X. (2005) Studies on mass summer mortality of cultured zhikong scallops (Chlamys farreri Jones et Preston) in China. Aquaculture, 250: 602-615.
Zillen, L., Conley, D.J., Andren, T., Andren, E., and Bjorck, S. (2008) Past occurrences of hypoxia in the Baltic Sea and the role of climate variability, environmental change and human impact. Earth-Science Reviews, 91: 77-92.
Zhang, Fl., He, Y., Liu, X., Ma J., Li, S. and Qi, L. (1991) Introduction, spat-rearing and experimental culture of bay scallop, Argopecten irradians lamarck. Chinese Journal of Oceanography and Limnology, 9: 123-131.
