Impacts of nutrient enrichment on coral reefs: new perspectives and implications for coastal management and reef survival

Impacts of nutrient enrichment on coral reefs: new perspectives and implications for coastal management and reef survival

Current Opinion in Environmental Sustainability, Volume 7, April 2014, Pages 82-93
Cecilia D’Angelo, Jörg Wiedenmann

http://doi.org/10.1016/j.cosust.2013.11.029

This article is in the Creative Commons.

This is a really nice review article that touches on many areas that are important to us as reefers.  As a result, it has a GREAT collection of citations that are pretty directly applicable to us and our situation.

A few quotes to whet the appetite – then go read!

We have recently shown that increased nutrient levels might not negatively affect the physiological performance of zooxanthellae as long as all essential nutrients are available at sufficient concentrations to ensure their chemically balanced growth 28.  These results could explain why some reefs and the nutritional status and metabolism of their inhabitants do not always show negative responses to eutrophication [29• ;  30•], at least in the absence of temperature and light stress.

We’ve already been making use of this fact….when you’re done reading this article, check out our post: A Nitrate Dosing Calculator For Better Tank Health (And Better Coral Color!)

Another tidbit from the article:

Most recently, however, we could demonstrate that corals exposed to elevated nitrogen levels were more susceptible to bleaching when exposed to heat and light stress [28]. Interestingly, the detrimental effects observed in these experiments could be attributed to the relative undersupply of phosphorus that resulted from the enhanced demand of the proliferating zooxanthellae population rather than to the elevated nitrogen levels themselves (Figure 1 ;  Figure 2).

 

We’ve been promoting this information (at least here on the blog) for quite a while now.

Fish foraging behavior changes plankton-nutrient relations in laboratory microcosms

Fish foraging behavior changesplankton-nutrient relations in laboratory microcosms

NOVALES-FLAMARIQUE, I., S. GRIESBACH, M. PARENT, A. CATTANEO, AND R. H. PETERS, Limnol. Oceanogr., 38(2), 1993, 290-298

Full article (PDF): http://aslo.net/lo/toc/vol_38/issue_2/0290.pdf

To demonstrate that the effects of higher trophic elements on plankton in laboratory aquaria are not simple top-down or bottom-up processes, we measured phosphorus and chlorophyll concentrations in replicated month-old aquaria undergoing one of five permutations involving three fish species, Daphnia pulex, and algae.

Seems like this could be useful in managing tanks.

Flicker Light Effects on Photosynthesis of Symbiotic Algae in the Reef- Building Coral Acropora digitifera (Cnidaria: Anthozoa: Scleractinia).

Flicker Light Effects on Photosynthesis of Symbiotic Algae in the Reef- Building Coral Acropora digitifera (Cnidaria: Anthozoa: Scleractinia).

Nakamura T, Yamasaki H. Flicker Light Effects on Photosynthesis of Symbiotic Algae in the Reef- Building Coral Acropora digitifera (Cnidaria: Anthozoa: Scleractinia). Pac Sci 62(3): 341-350.

http://hdl.handle.net/10125/22710

Complete article available.

At supersaturating light intensities, photosynthesis was less inhibited by flicker light than by constant light.

Due to the lens effect, light intensity in shallow-water environments sometimes reaches more than 9,000 mmol photons m 2 sec 1, corresponding to 300 to 500% of the surface light intensity (Schubert et al. 2001, in shallow estuary).

See also:

Results of the 1991 United States-Israel Workshop, “Nutrient Limitations in the Symbiotic Association between Zooxanthellae and Reef-building Corals”

Results of the 1991 United States-Israel Workshop, “Nutrient Limitations in the Symbiotic Association between Zooxanthellae and Reef-building Corals”

Jokiel PL, Dubinsky Z, Stambler N. 1994. Results of the 1991 United States-Israel Workshop, “Nutrient Limitations in the Symbiotic Association between Zooxanthellae and Reef-building Corals”. Pac Sci 48(3): 215-218.

http://hdl.handle.net/10125/2229

Micromorphometric technique (Berner and Izhaki 1994) as well as elemental analysis (Muller-Parker et al. 1994a) showed decreasing availability of surplus carbon, giving further evidence of an impaired symbiotic relationship in ammonium-enriched treatments.

The results of Muscatine and Kaplan (1994) remind us that corals may become “nutrient-limited” only under high light conditions that allow extremely high photosynthetic rates.

Further, different species of corals show different responses to the same alterations in nutrient regime (Stambler et al. 1994a).

…the argument is made that under normal conditions in nutrient-poor tropical seas, zooxanthellate corals are successful because they are closed systems with respect to nitrogen. Growth of zooxanthellae under these conditions is not balanced with respect to fixed carbon because of the low rate of nitrogen supply.

As a result, the excess carbon is translocated to the animal host. Increasing the nitrogen supply leads to rapid growth of the zooxanthellae, with consequent reduction of translocated carbon to the host. Eutrophic conditions allow the zooxanthellae to outgrow their hosts and the host loses control over the population of its symbiotic algae. Thus, main- tenance of a balanced coral symbiotic association appears to require low ambient nutrient concentrations.

See also: Ratio of Energy and Nutrient Fluxes Regulates Symbiosis between Zooxanthellae and Corals

Possible Refugia for Reefs in Times of Environmental Stress

Possible Refugia for Reefs in Times of Environmental Stress

Int J Earth Sci (Geol Rundsch) (2003) 92:520–531 DOI 10.1007/s00531-003-0328-9
B. Riegl · W. E. Piller

PDF available:

http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.160.3931&rep=rep1&type=pdf

This paper investigates the refuge potential of (1) upwelling areas, (2) coral areas at medium depth, and (3) offshore bank and island reefs

Ever wonder where Mother Nature moves her corals when her kids crash her display tank?  😉

Tissue and skeletal changes in the scleractinian coral Stylophora pistillata Esper 1797 under phosphate enrichment

Tissue and skeletal changes in the scleractinian coral Stylophora pistillata Esper 1797 under phosphate enrichment

Journal of Experimental Marine Biology and Ecology
Volume 409, Issues 1–2, 1 December 2011, Pages 200–207
http://dx.doi.org/10.1016/j.jembe.2011.08.022 Continue reading “Tissue and skeletal changes in the scleractinian coral Stylophora pistillata Esper 1797 under phosphate enrichment”