Abstract
One of the most remarkable sights in the Western Pacific is a perennial swarm of 1.5 million golden medusae (Mastigias sp.) crowded into a land-locked marine lake in Palau, Micronesia. This `Jellyfish Lake' became a popular off-gassing stopover for SCUBA divers and a destination in its own right for non-diving tourists in the mid-1980s. Since then, tourism in Palau has boomed, increasing 500% between 1986 and 1997. However, in December 1998, the golden-medusae disappeared. Apart from patchy occurrences between December 1998 and April 1999, the medusae have since been absent from the lake. Field measurements, including temperature and salinity depth profiles, Mastigias medusae population sizes, and the distribution of scyphistomae, in `Jellyfish Lake' between 1979 and 1999 were integrated with laboratory-based experiments on the effects of salinity, temperature, sunscreen and zooxanthellae enrichment on Mastigias scyphistomae or medusae. These studies indicated that the disappearance of medusae was due to physical changes in lake structure, including a substantial increase in temperature, initiated by the 1997–98 El Niño. Here, we describe these studies, the changes in Jellyfish Lake and their probable influence on the Mastigias. We further elucidate the changes in Jellyfish Lake by reference to coincident changes in three other `jellyfish lakes' in Palau: Big Jellyfish Lake, Clear Lake and Goby Lake.
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Arai, M. N., 1973. Behaviour of the planktonic coelenterates, Sarsia tubulosa, Phialidium gregarium and Pleurobrachia pileus in salinity discontinuity layers. J. Fish. Res. Bd Can. 30: 1105–1110.
Arai, M. N., 1976. Behaviour of planktonic coelenterates in temperature and salinity discontinuity layers. In Mackie, G. O. (ed.), Coelenterate Ecology and Behaviour. Plenum Press, New York: 211–218.
Arai, M. N., 1992. Active and passive factors affecting aggregations of hydromedusae: a review. Sci. mar. 56: 99–108.
Arai, M. N., 1997. A functional biology of Scyphozoa. Chapman & Hall, London: 316 pp.
Aronson, R. B., W. F. Precht, I. G. Macintyre & T. J. T. Murdoch, 2000. Coral bleach-out in Belize. Nature 405: 36.
Barbour, N., 1990. Palau. Full Court Press, San Francisco, 160 pp.
Brown, B. E., R. P. Dunne & H. Chasang, 1996. Coral bleaching relative to elevated seawater temperature in the Andaman Sea (Indian Ocean) over the last 50 years. Coral Reefs 15: 151–152.
Chavez, F. P., P. G. Strutton, G. E. Friederich, R. A. Feely, G. C. Feldman, D. G. Foley & M. J. McPhaden, 1999. Biological and chemical response of the equatorial Pacific Ocean to the 1997–98 El Niño. Science 286: 2126–2131.
Condon, R., M. B. Decker & J. E. Purcell, 2001. Effects of low dissolved oxygen on survival and asexual reproduction of scyphozoan polyps (Chrysaora quinquecirrha). Hydrobiologia 451 (Dev. Hydrobiol. 155): 89–95.
Dawson, M. N, 2000. Variegated mesocosms as alternatives to shore-based planktonkreisels: notes on the husbandry of jellyfish from marine lakes. J. Plankton Res. 22: 1673–1682.
Dawson, M. N., K. A. Raskoff & D. K. Jacobs, 1998. Preservation of marine invertebrate tissues for DNA analyses. Molec. Mar. Biol. Biotech.7: 145–152.
Etpison, M. T., 1997. Palau: portrait of paradise. Neco Marine, Koror: 250 pp.
Fautin, D. G. & W. K. Fitt, 1991. A jellyfish-eating anenome (Cnidaria, Actinaria) from Palau – Entacmaea medusivora-sp. nov. Hydrobiologia 216: 453–461.
Glynn, P. W. & L. D'Croz, 1990. Experimental evidence for high temperature stress as the cause of El Niño-coincident coral mortality. Coral Reefs 8: 181–191.
Hamner, W. M., 1982. Strange world of Palau's salt lakes. Nat. Geogr. 161: 264–282.
Hamner, W. M., 1994. Current biological status (1994) of Jelly-fish Lake, Macharchar. Report prepared for Division of Marine Resources, Republic of Palau.
Hamner, W. M. & P. P. Hamner, 1998. Stratified marine lakes of Palau (Western Caroline Islands). Phys. Geogr. 19: 175–220.
Hamner, W. M. & I. R. Hauri, 1981. Long-distance horizontal migrations of zooplankton (Scyphomedusae: Mastigias). Limnol. Oceanogr. 26: 414–423.
Hamner, W. M., R. W. Gilmer & P. P. Hamner, 1982. The physical, chemical and biological characteristics of a stratified, saline, sulfide lake in Palau. Limnol. Oceanogr. 27: 896–909.
Hamner, W. M., P. P. Hamner & S. W. Strand, 1994. Sun-compass migration by Aurelia aurita (Scyphozoa): population retention and reproduction in Saanich Inlet, British Columbia. Mar. Biol. 119: 347–356.
Harder, W., 1968. Reactions of planktonic organisms to water stratification. Limnol. Oceanogr. 13: 156–168.
Hayes, R. L. & P. G. Bush, 1990. Microscopic observations of recovery in the reef-building scleractinian coral, Montastrea annularis, after bleaching on a Cayman reef. Coral Reefs 8: 203–209.
Hoegh-Guldberg, O. & J. G. Smith, 1989. The effect of sudden changes in temperature, light and salinity on the population density and export of zooxanthellae from the reef corals Stylophora pistillata Esper and Seriatopora hystrix Dana. J. exp. mar. Biol. Ecol. 129: 279–303.
Jones, R. J., R. Berkelmans & J. K. Oliver, 1997. Recurrent bleaching of corals at Magnetic Island (Australia) relative to air and seawater temperature. Mar. Ecol. Prog. Ser. 158: 289–292.
Kleppel, G. S., R. E. Dodge & C. J. Reese, 1989. Changes in pigmentation associated with the bleaching of stony corals. Limnol. Oceanogr. 34: 1331–1335.
Kuroki, T. & R. Van Woesik, 1999. Changes in zooxanthellae characteristics in the hermatypic coral Stylophora pistillata during a 'bleaching event'. Galaxea 1: 97–101.
Lance, J., 1962. Effects of water of reduced salinity on the vertical migration of zooplankton. J. mar. biol. Ass. U.K. 42: 131–154.
Lucas, C. H., 2001. Reproduction and life history strategies of the common jellyfish, Aurelia aurita, in relation to its ambient environment. Hydrobiologia 451 (Dev. Hydrobiol. 155): 229–246.
McCloskey, L. R., L. Muscatine & F. P. Wilkerson, 1994. Daily photosynthesis, respiration and carbon budgets in a tropical marine jellyfish (Mastigias sp.). Mar. Biol. 119: 13–22.
McPhaden, M. J., 1999. Genesis and evolution of the 1997–98 El Niño. Science 283: 950–954.
Muscatine, L. & R. E. Marian, 1982. Dissolved inorganic nitrogen flux in symbiotic and nonsymbiotic medusae. Limnol. Oceanogr. 27: 910–917.
Muscatine, L., F. P. Wilkerson & L. R. McCloskey, 1986. Regulation of population density of symbiotic algae in a tropical marine jellyfish (Mastigias sp.). Mar. Ecol. Prog. Ser. 32: 279–290.
NOAA, 1999a. TAO/TRITON times series plot. http://www.pmel.noaa.gov/toga-tao/realtime.html
NOAA, 1999b. El Niño theme page. http://www.pmel.noaa.gov/toga-tao/el-n ino/nino-home.html
PCS, 1999a. Palau's Taiwanese tourism industry: assessment of issues and suggestions for the future. PCS report 99-04. Palau Conservation Society, Koror: 42 pp.
PCS, 1999b. Current status of Palau's corals. PCS newsletter, No.11, July 1999: 4.
PVA, 1999. Palau recognized as a top world destination. Palau Visitors Authority press release. Tia Belau, Koror, 5th December 1999.
Purcell, J. E., J. R. White, D. A. Nemazie & D. A. Wright, 1999. Temperature, salinity and food effects on asexual reproduction and abundance of the scyphozoan Chrysaora quinquecirrha. Mar. Ecol. Prog. Ser. 180: 187–196.
Rahat, M. & O. Adar, 1980. Effect of symbiotic zooxanthellae and temperature on budding and strobilation in Cassiopeia andromeda (Eschscholz). Biol. Bull. 159: 394–401.
Rowan, R. & N. Knowlton, 1995. Intraspecific diversity and ecological zonation in coral-algal symbiosis. Proc. natl. Acad.Sci. U.S.A. 92: 2850–2853.
Seutin, G., B. N. White & P. T. Boag, 1991. Preservation of avian blood and tissue samples for DNA analyses. Can. J. Zool. 69: 82–90.
Sugiura, Y., 1964. On the life-history of rhizostome medusae. II. Indispensability of zooxanthellae for strobilation in Mastigias papua. Embryologia 8: 223–233.
Sugiura, Y., 1965. On the life-history of rhizostome medusae. III. On the effects of temperature on the strobilation of Mastigias papua. Biol. Bull. 128: 493–496.
Uye, S., 1994. Replacement of large copepods by small ones with eutrophication of embayments: causes and consequences. Hydrobiologia 292/293: 513–519.
Watanabe, T. & H. Ishii, 2001. In situ estimation of ephyrae liberated from polyps of Aurelia aurita using settling plates in Tokyo Bay, Japan. Hydrobiologia 451 (Dev. Hydrobiol. 155): 247–258.
Weiler, K. S. & R. E. Black, 1991. Immediate decrease in apparent translation rate caused by salinity change in scyphistomae of Aurelia aurita (Linnaeus). Comp. Biochem. Physiol. 99A: 199–202.
Wilkinson, C., O. Linden, H. Cesar, G. Hodgson, J. Rubens & A. E. Strong, 1999. Ecological and socioeconomic impacts of 1998 coral mortality in the Indian Ocean: an ENSO impact and a warning of future change? Ambio 28: 188–196.
Winter, A., R. S. Appeldoorn, A. Bruckner, E. H. Williams Jr. & C. Goenaga, 1998. Sea surface temperatures and coral reef bleaching off La Parguera, Puerto Rico (northeastern Caribbean Sea). Coral Reefs 17: 377–382.
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Dawson, M.N., Martin, L.E. & Penland, L.K. Jellyfish swarms, tourists, and the Christ-child. Hydrobiologia 451, 131–144 (2001). https://doi.org/10.1023/A:1011868925383
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DOI: https://doi.org/10.1023/A:1011868925383