Interesting, in a positive way I mean.
I am looking forward to more information regarding this.
Here are a few references/abstracts to start with if your interested in the topic. By supplying this information, I am not in any way suggesting that an ATS is detrimental to corals. There is a lot of considerations and overall, I believe that they are beneficial. Also, while many of these references discuss algae adding to DOC, I haven't seen evidence that this is an issue with ATS systems. My issue is more that they are not a complete means of filtration as they are not removing DOC. Again, whether or not this is an issue depends on a lot of things and in most cases it isn't.
Another consideration, that I would mention, while on the topic is that the response isn't as fast as a skimmer. What I mean is that with a skimmer if something dies, a properly sized skimmer will remove it pretty efficiently. With an ATS, it needs to break down and increased algae growth needs to occur before the contamination is dealt with. This may have more lag time. Again though, many people run ATS systems and deal with this through other means, such as monitoring and water changes. However, I still prefer the insurance of a skimmer... just my .02.
Anyways, here are some abstracts. If you search google scholar for them, and look at the citations and citing articles, there are lots more. Also, if something interests you, you may want to try to read the article. Abstracts don't present the entire picture. Some are freely available. I have access to most if not, so, I may be able to answer specific questions if it doesn't require too much time.
Neilan M. Kuntz, David I. Kline, Stuart A. Sandin, Forest Rohwer. (2005)
Pathologies and mortality rates caused by organic carbon and nutrient stressors in three Caribbean coral species. MEPS: 294:173-180
Abstract
Anthropogenic inputs, including organic carbon and nutrient loading, are increasingly changing the water quality on coral reefs. Herein we show that treating Montastraea annularis, Agaricia tenuifolia and Porites furcata with various organic carbon sources (starch, lactose, arabinose and mannose) results in different species-specific and carbon-specific pathologies and rates of mortality. The variation in the pathological characteristics caused by stressors showed that visual cues for determining coral health and disease may be misleading. The probability of mortality increased significantly over time with continual exposure to several of the stressors, suggesting that chronic stressors may be more harmful than acute stressors. In contrast to the organic carbon sources, high concentrations of nutrients (phosphate, ammonium and nitrate) did not directly kill corals. The variation in coral responses to anthropogenic stressors means that changes on disturbed coral reefs will depend on the type of and duration of exposure to the stressor, as well as on the species of coral.
David I. Kline, Neilan M. Kuntz, Mya Breitbart, Nancy Knowlton, Forest Rohwer (2006), Role of elevated organic carbon levels and microbial activity in coral mortality. Mar Ecol Prog Ser: 314: 119–125
Abstract
Coral reefs are suffering a long-term global decline, yet the causes remain contentious. The role of poor water quality in this decline is particularly unclear, with most previous studies providing only weak correlations between elevated nutrient levels and coral mortality. Here we experimentally show that routinely measured components of water quality (nitrate, phosphate, ammonia) do not cause substantial coral mortality. In contrast, dissolved organic carbon (DOC), which is rarely measured on reefs, does. Elevated DOC levels also accelerate the growth rate of microbes living in the corals’ surface mucopolysaccharide layer by an order of magnitude, suggesting that mortality occurs due to a disruption of the balance between the coral and its associated microbiota. We propose a model by which elevated DOC levels cause Caribbean reefs to shift further from coral to macroalgal dominance. Increasing DOC levels on coral reefs should be recognized as a threat and routinely monitored.
Smith, J. E., Shaw, M., Edwards, R. A., Obura, D., Pantos, O., Sala, E., Sandin, S. A., Smriga, S., Hatay, M. and Rohwer, F. L. (2006), Indirect effects of algae on coral: algae-mediated, microbe-induced coral mortality. Ecology Letters, 9:**835–845.
Abstract
Declines in coral cover are generally associated with increases in the abundance of fleshy algae. In many cases, it remains unclear whether algae are responsible, directly or indirectly, for coral death or whether they simply settle on dead coral surfaces. Here, we show that algae can indirectly cause coral mortality by enhancing microbial activity via the release of dissolved compounds. When coral and algae were placed in chambers together but separated by a 0.02**μm filter, corals suffered 100% mortality. With the addition of the broad-spectrum antibiotic ampicillin, mortality was completely prevented. Physiological measurements showed complementary patterns of increasing coral stress with proximity to algae. Our results suggest that as human impacts increase and algae become more abundant on reefs a positive feedback loop may be created whereby compounds released by algae enhance microbial activity on live coral surfaces causing mortality of corals and further algal growth.
Katie L. Barott, Beltran Rodriguez-Mueller, Merry Youle, Kristen L. Marhaver, Mark J. A. Vermeij, Jennifer E. Smith, and Forest L. Rohwer (2011) Microbial to reef scale interactions between the reef-building coral Montastraea annularis and benthic algae Proc R Soc B: rspb.2011.2155v1-rspb20112155.
Abstract
Competition between reef-building corals and benthic algae is of key importance for reef dynamics. These interactions occur on many spatial scales, ranging from chemical to regional. Using microprobes, 16S rDNA pyrosequencing and underwater surveys, we examined the interactions between the reef-building coral Montastraea annularis and four types of benthic algae. The macroalgae Dictyota bartayresiana and Halimeda opuntia, as well as a mixed consortium of turf algae, caused hypoxia on the adjacent coral tissue. Turf algae were also associated with major shifts in the bacterial communities at the interaction zones, including more pathogens and virulence genes. In contrast to turf algae, interactions with crustose coralline algae (CCA) and M. annularis did not appear to be antagonistic at any scale. These zones were not hypoxic, the microbes were not pathogen-like and the abundance of coral–CCA interactions was positively correlated with per cent coral cover. We propose a model in which fleshy algae (i.e. some species of turf and fleshy macroalgae) alter benthic competition dynamics by stimulating bacterial respiration and promoting invasion of virulent bacteria on corals. This gives fleshy algae a competitive advantage over corals when human activities, such as overfishing and eutrophication, remove controls on algal abundance. Together, these results demonstrate the intricate connections and mechanisms that structure coral reefs.