[CDHC] New publication on coral pathologies associated with hyposalinity

Cheryl Woodley cheryl.woodley at noaa.gov
Mon Aug 17 19:49:36 EDT 2009

Dear CDHC Members
I wanted to let you know of a new publication by several CDHC members in 
the journal Science of the Total Environment that may be of interest to you.

Craig A. Downs, Esti Kramarsky-Winter, Cheryl M. Woodley, Aaron Downs,
Gidon Winters, Yossi Loya, Gary K. Ostrander. 2009. Cellular pathology
and histopathology of hypo-salinity exposure on the coral Stylophora
pistillata. Science of the Total Environment.
doi:10.1016/j.scitotenv.2009.05.015. First On line

Coral reefs can experience extreme salinity changes, particularly
hypo-salinity, as a result of storms, heavy rainy seasons (e.g.,
monsoons), and coastal runoff. Field and laboratory observations have
documented that corals exposed to hypo-saline conditions can undergo
extensive bleaching and mortality. There is controversy in the
literature as to whether hypo-saline conditions induce a pathological
response in corals, and if there is a relationship between decreasing
salinity treatment and pathological responses. To test the hypothesis
that hypo-salinity exposure does not have a pathological effect on
coral, we used histological and cellular diagnostic methods to
characterize the pathology in hypo-salinity-exposed corals. Colonies of
Stylophora pistillata were exposed to five salinity concentrations [39
parts per thousand (ppt), 32 ppt, 28 ppt, 24 ppt, and 20 ppt] that may
realistically occur on a reef. Histological examination indicated an
increasing severity of pathomorphologies associated with decreasing
salinity, including increased tissue swelling, degradation and loss of
zooxanthellae, and tissue necrosis. Pulse-amplitude modulated
chlorophyll fluorimetry kinetics demonstrated a decreasing
photosynthetic efficiency with decreasing salinity conditions.
Cytochrome P450 levels were affected by even slight changes in salinity
concentration suggesting that
detoxification pathways, as well as several endocrine pathways, may be
adversely affected. Finally, these studies demonstrated that hypo-saline
conditions can induce an oxidative-stress response in both the host and
in its algal symbiont, and in so doing, may synergistically increase
oxidative-stress burdens. As with other types of environmental stresses,
exposure to hypo-saline conditions may have long-term consequences on
coral physiology.

Cheryl Woodley, Ph.D.
Coral Health and Disease Program

Center for Coastal Environmental Health and Biomolecular Research
Hollings Marine Laboratory
331 Fort Johnson Rd
Charleston, SC 29412
843.762.8862 Phone
843.762.8737 Fax
cheryl.woodley at noaa.gov

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