Variation in measures of immunocompetence of sea fan coral, Gorgonia ventalina, in the Florida Keys
Aspergillosis is a widespread disease that has impacted the demography of the Caribbean sea fan coral, Gorgonia ventalina. The innate coral immune defenses can be measured as constitutive levels of immune proteins (peroxidase [POX], prophenoloxidase [PPO], lysozyme-like activity [LYS], exochitinase [EXOC]), antioxidant (superoxide dismutase [SOD]), and antimicrobial (antibacterial [AB] and antifungal [AF]) activity. Therefore, variations in these parameters across a geographic region could provide clues to the role of environment in disease. This study examined healthy sea fans collected in July 2005 from six offshore sites in the Florida Keys lying between 24.569°N and 25.220°N, a distance of ~145 km. Contrary to expectations, small (<15 cm) colonies did not differ significantly from large colonies (>15 cm) in the protein-based levels of activity in any of the measured parameters. However, there were significant differences in many of the parameters among sites, and Molasses Reef and Looe Key Reef were the most different in POX, PPO, SOD, and AF activity. This suggests that there are potential site-specific environmental factors that shape the immune physiology of colonies. Several proxies of environmental stress were also regressed against levels of the immune parameters. The proxies included 10 year averages of benthic community composition, 5 year averages of water quality, and historic aspergillosis disease prevalence and severity. Generality about environmental drivers was limited by assaying only six sites, but several patterns did emerge. SOD, EXOC, and AF activity were all correlated with percent bare substrate cover, suggesting that certain immune components may be activated in low coral environments. LYS and EXOC activity were positively correlated with dissolved inorganic nitrogen (DIN), one proxy of water quality. There were no relationships between any of the measured immune parameters and previous disease prevalence and severity. This study is a first step in evaluating levels of within- and between-site variation in coral immunity and investigating possible environmental drivers.
KeywordsAspergillosis Dissolve Inorganic Nitrogen Molasses Immune Measure Scleractinian Coral Cover
Research was supported by the NSF/NIH Ecology of Infectious Disease Program (NSF OCE-0326705), and Coral Disease Working Group of the GEF-World Bank CRTR Program. CREMP ecological survey data were provided by Michael Callahan at the Florida Fish and Wildlife Research Institute. Water data were provided by the SERC-FIU Water Quality Monitoring Network which is supported by SFWMD/SERC Cooperative Agreements #4600000352 as well as EPA Agreement #X994621-94-0. We thank D. Baker and K. Kim for field support and A. Kessler for experimental support. We are grateful to E. Bartels at Mote Tropical Marine Laboratory in Summerland Key, Florida and L. Anderson at Keys Marine Lab, Long Key, Florida for collections and dive support. We would also like to thank G. Smith for supplying the bacteria isolate used for the AB assay. Statistical assistance was provided by Cornell University Statistical Consulting Unit and J. Simonis. Samples were collected under Florida Keys National Marine Sanctuary Permit # 2004-092.
- Beaver C, Brooke S, Callahan M, Johnson D, Kidney J, Kupfner S et al. (2006) Coral reef evaluation and monitoring project 2005 executive summary EPA steering committee meeting June 2006. Florida fish and wildlife conservation commissionGoogle Scholar
- Bowler C, Van Montagu M, Inze D (1992) Superoxide dismutase and stress tolerance. Annu Rev Plant Physiol Plant Mol Biol 43:83–116. doi: https://doi.org/10.1146/annurev.pp.43.060192.000503 CrossRefGoogle Scholar
- Boyer JN, Briceño HO (2005) FY2005 annual report of the water quality monitoring project for the water quality protection program of the Florida Keys national marine sanctuary. Southeast environmental research center, Technical Report #T-327Google Scholar
- Fauth JE, Dustan P, Pante E, Banks K, Vargas-Angel B, Downs CA (2006) Final report: Southeast Florida coral biomarker local action study. Office of coastal and aquatic managed areas, of the Florida department of environmental protectionGoogle Scholar
- Kim K, Harvell CD (2002) Aspergillosis of sea fan corals: disease dynamics in the Florida Keys. In: Porter JW, Porter KG (eds) The everglades, Florida bay, and coral reefs of the Florida Keys: an ecosystem sourcebook. CRC Press, Boca Raton, pp 813–824Google Scholar
- Krishnan N, Chattopadhyay S, Kundu JK, Chaudhuri A (2002) Superoxide dismutase activity in hemocytes and hemolymph of Bombyx mori following bacterial infection. Curr Sci 83:321–325Google Scholar
- Manduzio H, Monsinjon T, Galap C, Leboulenger F, Rocher W (2004) Seasonal variations in antioxidant defenses in blue mussels Mytilus edulis collected from a polluted area: major contributions in gills of an inducible isoform of Cu/Zn-superoxide dismutase and of glutathione S-transferase. Aquat Toxicol 70:83–93. doi: https://doi.org/10.1016/j.aquatox.2004.07.003 CrossRefGoogle Scholar
- Mydlarz LD, Jones LE, Harvell CD (2006) Innate immunity environmental drivers and disease ecology of marine and freshwater invertebrates. Annu Rev Ecol Evol Syst 37:251–288. doi: https://doi.org/10.1146/annurev.ecolsys.37.091305.110103 CrossRefGoogle Scholar
- Nugues MM, Nagelkerken I (2006) Status of aspergillosis and sea fan populations in Curacao 10 years after the 1995 Caribbean epizootic. Rev Biol Trop 54:153–160Google Scholar
- Thevissen K, Osborn RW, Acland DP, Broekaert WF (2000) Specific binding sites for an antifungal plant defensin from dahlia (Dahlia merckii) on fungal cells are required for antifungal activity. Mol Plant Microbe Interact 13:54–61. doi: https://doi.org/10.1094/MPMI.2000.13.1.54 CrossRefGoogle Scholar
- Turner DJ, Kildea TN, Westphalen G (2007) Examining the health of subtidal reef environments in South Australia, Part 2: status of selected South Australian reefs based on the results of the 2005 surveys. South Australian Reef and Development Institute (Aquatic Sciences), SARDI Publication Number RD03/0252-6, AdelaideGoogle Scholar
- Weil E (2004) Coral reef diseases in the wider Caribbean. In: Rosenberg E, Loya Y (eds) Coral health and disease. Springer, pp 35–68Google Scholar