Long-term effects of nutrient and CO2 enrichment on the temperate coral Astrangia poculata (Ellis and Solander, 1786)

Long-term effects of nutrient and CO2 enrichment on the temperate coral Astrangia poculata (Ellis and Solander, 1786)


DOI: 10.1016/j.jembe.2010.02.007

PDF Available

Nutrient limited corals are unable to utilize an increase in dissolved inorganic carbon (DIC) as nutrients are already limiting growth, thus the effect of elevated CO2 on saturation state drives the calcification response. Under nutrient replete conditions, corals may have the ability to utilize more DIC, thus the calcification response to CO2 becomes the product of a negative effect on saturation state and a positive effect on gross carbon fixation, depending upon which dominates, the calcification response can be either positive or negative.

Role of elevated organic carbon levels and microbial activity in coral mortality

Role of elevated organic carbon levels and microbial activity in coral mortality

David I. Kline, Neilan M. Kuntz, Mya Breitbart, Nancy Knowlton, Forest Rohwer

Marine Ecology Progress Series, Vol. 314 (May 22 2006), pp. 119-125

Stable URL: http://www.jstor.org/stable/24870119

PDF available

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.

‘Nuff said!

But the whole article is available, so as usual – click through and read it!

Book: Biology of Stress In Fish – Fish Physiology (Chapter 12 – Stress Management And Welfare)

Book: Biology of Stress In Fish – Fish Physiology (Chapter 12 – Stress Management And Welfare)

Lynne U Sneddon, David C.C. Wolfenden, Jack S Thomson
Biology of Stress in Fish – Fish Physiology, pp.463-539

The Chapter 12 authors have posted their work on Research Gate here:

DOI: 10.1016/B978-0-12-802728-8.00012-6 (Science Direct)

There is not only a lack of familiarity with what constitutes stress and what side-effects stress can have, but there’s even a pretty fair amount of denial of it’s role in health and sickness.  All of that is laid fairly to rest in this book.

For example from this chapter, we can learn:

  • Short term (acute) stress – like being caught in a net – isn’t so bad for a fish.  It’s just a coping mechanism and long term consequences would not be expected.
  • Long term (chronic) stress – like three months in QT with a pack of strange fish – will have a more lasting negative impact on growth, immunity and reproduction.

In spite of how much of the book is online, they don’t allow quoting from any of it from any source I’ve found, so you can read the rest for yourself!


Programmed cell death in protists

Programmed cell death in protists

Marcel Deponte


This is a great review article for us!

In the case of the blooming dinoflagellates, Vardi et al. suggested that by allowing only the best adapted individuals to establish cysts, while eliminating less healthy members of the community at the end of the bloom, programmed cell death might confer a selective advantage to a population during subsequent seasons.

The main part of interest will surely be Table 1 in the document where each protist and it’s programmed cell-death details are indexed.

Microbial Community Management in Aquaculture

Microbial Community Management in Aquaculture

Procedia Food Science, Volume 6, 2016, Pages 37-39
P. Bossier, P. De Schrijver, T. Defoirdt, H.A.D. Ruwandeepika, F. Natrah, J. Ekasari, H. Toi, D. Nhan, N. Tinh, G. Pande, I. Karunasagar, G. Van Stappen


Under a Creative Commons license

The expansion of the aquaculture production is restricted due to the pressure it causes on the environment by the discharge of waste products in the water bodies and by its dependence on fish oil and fishmeal. Aquaculture using bio-floc technology (BFT) offers a solution to both problems.

All biofloc size classes were consumed and utilized by the shrimp, tilapia and mussel. The highest retention of nitrogen in the animal body, however, was consistently originating from the bioflocs larger than 100μm

Survival in the [immunity] challenge tests with shrimp from the biofloc [fed] groups, was also significantly higher compared to the positive control.

Rather than trying to control microbial community composition, microbial activity can be steered. The disruption of quorum sensing, bacterial cell-to-cell communication, has been suggested as an alternative strategy to control infections in aquaculture 5.

Recent studies also indicate that opportunistic aquatic pathogens[…]are also able to sense host clues such as stress hormones.


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


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.

Antimicrobial Peptides from Fish

Antimicrobial Peptides from Fish

Jorge A. Masso-Silva and Gill Diamond

Pharmaceuticals 20147(3), 265-310; doi:10.3390/ph7030265

“AMP” = antimicrobial peptide

Piscidins exhibit potent antimicrobial activity against a variety of microorganisms.

They are widely active against bacteria Gram-positive and -negative species…

Piscidins have also been shown to possess anti-fungal activity, anti-parasitic activity, and anti-viral activity.

Piscidins are mainly expressed in gill, skin and intestine, although can be also found in head-kidney and spleen. However, in Atlantic cod piscidin was found to be ubiquitous, being detected in chondrocytes, heart, oocytes, exocrine and endocrine glands, swim bladder, and other tissues.

Like AMP genes from mammals, piscidin genes can be induced by a variety of stimuli, including Gram-positive and -negative bacteria, bacteria cell components like LPS or the bacterial antigen ASAL.

Furthermore, piscidin genes are induced by parasites, viruses,…

Another study demonstrated that high biomass density (i.e., a higher concentration of fish per volume water in an experimental tank) used as an acute stressor component, led to an to up-regulation of dicentracin in gills and skin as well.

Histone-derived AMPs have been identified in a number of fish species, with broad-spectrum activity against both human and fish pathogens, including water molds and a parasitic dinoflagellate. They are expressed and secreted in fish skin, and found in other tissues, including gill, speen and the gut.

Further evidence that they play a role in host defense of the fish comes from studies showing that expression of histone-derived AMP genes are induced under conditions of stress in specific tissues of different fish species.

This is just a sample of quotes that focuses only on piscidins and histidins, where the review article goes on at length with lots more good info.

There really should be no doubt about a healthy fish’s ability to defend itself.

The doubt should be focused on whether, or how much, we limit or support their abilities with stress and nutrition.