Nutrient enrichment can increase the severity of coral diseases

Abstract

The prevalence and severity of marine diseases have increased over the last 20 years, significantly impacting a variety of foundation and keystone species. One explanation is that changes in the environment caused by human activities have impaired host resistance and/or have increased pathogen virulence. Here, we report evidence from field experiments that nutrient enrichment can significantly increase the severity of two important Caribbean coral epizootics: aspergillosis of the common gorgonian sea fan Gorgonia ventalina and yellow band disease of the reef‐building corals Montastraea annularis and M. franksii. Experimentally increasing nutrient concentrations by 2–5× nearly doubled host tissue loss caused by yellow band disease. In a separate experiment, nutrient enrichment significantly increased two measures of sea fan aspergillosis severity. Our results may help explain the conspicuous patchiness of coral disease severity, besides suggesting that minimizing nutrient pollution could be an important management tool for controlling coral epizootics.

Bioindicators of changes in water quality on coral reefs: review and recommendations for monitoring programmes

“…The next section and Table 2 provide a brief description of the main properties of these bioindicators. In order to facilitate the systematic comparison of bioindicators and to assess their suitability to detect either chronic or acute changes in water Jones and Kaly (1996), Erdmann and Caldwell (1997), and Jameson et al (1998) Bruno et al 2003) Coral diseases Dissolved organic carbon Species-specific responses in mortality of Montastrea annularis, Agaricia tenuifolia and Porites furcata exposed to different sources of DOC. Mortality increased over time suggesting chronic exposure is potentially more deleterious than acute exposure (Kuntz et al 2005) quality, an assessment framework (Table 3) was developed based on the five selection criteria.…”

Ecological Shifts along the Florida Reef Tract: The Past as a Key to the Future

“…In fact, evidence linking anthropogenic nutrients to coral reef decline in Florida remains correlative. The most important consequences of increased nutrification may, however, lie in an increase in the severity and duration of coral diseases (Bruno et al 2004) and in the inability of coral reefs to recover from disturbance events, especially if human activities serve to increase the frequency and/or intensity of the disturbance regime (McCook, Wolanski, and Spagnol 2001).…”

“…Beginning in the 1970s and continuing through today, coral diseases or disease-like syndromes have appeared in other coral species throughout the Caribbean (Antonius 1977;Edmunds 1991;Nagelkerken et al 1997;Santavy et al 1999;Garzon-Ferreira et al 2001), Bermuda (Garrett and Ducklow 1975), and the Florida Keys (Dustan and Halas 1987;Kuta and Richardson 1996;Richardson et al 1998;Santavy et al 2001;Patterson et al 2002). Other environmental stressors such as pollution, increased nutrients, increased iron supply, African dust, and temperature may be associated with coral disease outbreaks, yet no firm connections have been established (Shinn 1996(Shinn , 2001Epstein et al 1998;Hayes and Goreau 1998;Harvell et al 1999;Hayes et al 2001;Jackson et al 2001;Richardson and Aronson 2002;Bruno et al 2004). Antonius (1977) described a white syndrome in acroporid corals, which he termed shut-down reaction (SDR).…”

The roles of endolithic fungi in bioerosion and disease in marine ecosystems. II. Potential facultatively parasitic anamorphic ascomycetes can cause disease in corals and molluscs

“…In this context, cnidarian-associated fungi are better investigated than those found on molluscs. Gorgonian aspergillosis increases with nutrient enrichment (Bruno et al 2003). Black bands in corals were identified as concentrations of microborers, green algae and Aspergillus -like fungi (Bak and Laane 1987; Priess et al 2000).…”