View Full Version : Reef safe macroalgae?

07/22/2016, 06:12 PM
Does anyone know of any truly reef safe decorative macro algae? let me explain.....

When i was setting up my latest tank I was looking for movement so I thought maiden hair would be a nice macro and would compliment the sps side by having a moving side; a little haven for pipefish and gobies to dart in and out of.

Then I found a marine study and: no go on the maidens hair.

Turtleweed has been a focus of several studies in recent years examining the potential impacts of macroalgae on coral reefs. In recent decades, some reefs that were formerly dominated by coral are now dominated by macroalgae. There has been significant concern that interactions with some species of macroalgae may suppress the recovery of some coral species following disturbance or damage. Rashera et al. (2011) found that numerous species of macroalgae directly damage corals by transferring competitor-suppressing hydrophobic allelochemicals present on algal surfaces. These hydrophobic compounds, which include two acetylated diterpenes from Turtleweed, cause coral bleaching, decreased photosynthesis, and even coral death. Some studies have found negative impacts on corals by Turtleweed and some other algae even without physical contact. Birrell et al. (2008) found that the presence of nearby Turtleweed delayed the settlement of larvae of the coral Acropora millepora, apparently via some sort of waterborne effects.

So this got me thinking and I am pondering what if any decorative macro are reef safe? We know softies use chem warfare so the question becomes what other macros may do the same?

I am asking you experts of the macroalgal kingdoms for any experiences anecdotal or studies.

07/22/2016, 06:55 PM
Yes, I have seen some of those studies.

For the same reason reef hobbiest use activated carbon to offset chemical warefare between coral, activated carbon should be used in a macro algae tank. DOC (dissolved organic carbon) is another reason to use activated carbon. While protein skimming, at best, removes 30% of DOC, activated carbon removes 70-80%.

It is well known that coral reefs would be algae dominated, if it were not for herbivores. I have seen a study that showed a macro algae when moved near a hard coral suppressed the growth of the coral at the expense of increased fish grazing.

07/22/2016, 07:00 PM
With respect to your SPS tank, pulse macros would work best. They handle periods of low nutrients and are long lived. Pulse macros include; Mermaid's Fan, Condium, Fauchae and Pink Galaxy.

07/22/2016, 07:39 PM
Ty. I am running carbons; however, I am curious if there are any macro algae no known for sending off mass supression techniques.

07/22/2016, 08:08 PM
I suppose there are. A few years ago a graduate student I knew studied mass die off of turtle grass near the Yukatan peninsula, but only in patches. Oddly enough when the nutrients were released, the new sprouts of turtle grass were grazed heavily by sea turtles.

What you are looking for is a complex interacting dynamic process best discribed as the "coral holobiont". Forest Rohwer's book "Coral Reefs in the Microbial Seas" goes to the heart of the matter.
DOC feeds bacteria.

DOC released by coral promote autotrophic or oxygen enriching microbes.

DOC released by folacious (nuisance) algae promote heterotrophic or oxygen reducing microbes.

The Gulf of Mecico in deep water far offshore has the largest anarobic body of water in the world. We sometime see the result of this in the form of "red tides" that come ashore.

07/23/2016, 08:44 PM

I took lessons today on copy and paste. For the many that ask the same question on stocking a refugium, this should be a sticky.

07/24/2016, 09:25 AM
ty Subsea. i understand the basics of macros and nutrient export. I am specifically seeking knowledge on macro chemical warfare.

07/24/2016, 02:39 PM
I put the link out there for other people's reference.

If you google macro algae chemical warfare, you will find plenty to read. In your initial post, you referenced chemical warfare of tumble weed, which is a true marine plant. Reef hobbiest have known for years about chemical warfare between soft corals and hard corals. It makes one wonder how reefs can survive.

07/24/2016, 06:39 PM
Quite simply they don't when macros come in. It appears acropora and stylos actually release a chemical that attracts certain species of fish that attack the macroalgae

07/24/2016, 08:13 PM
Fish grazing on macro algae is the natural order of things. Some macro has growth mechanisms to inhibit fish grazing. The study that I read indicated then when a certain species of macro was placed in the vicinity of a hard coral, the macro inhibited the growth of the coral, but sacrificed its fish grazing enzymes and was reduced. Sounds like a form of self regulation for the system as a whole.

A lot of the changes from coral dominated to macro dominate reefs has much to do with loss of herbivores.