[Coral-List] fish and algae

Szmant, Alina szmanta at uncw.edu
Tue Feb 18 10:48:43 EST 2014

Hi Denny:

We don't have to refer to some obscure for no-reef scientists predation-damselfish-algal lawn/kill coral example to make the case that human disturbance can result in unfortunate ecological disfunction and dis-service to use Steve's term:  think wolves-deer-over grazing (and then people hating deer for eating their flowers) as a close to home example.


"Great minds discuss ideas; average minds discuss events; small minds discuss people." Eleanor Roosevelt

"The time is always right to do what is right"  Martin Luther King

Dr. Alina M. Szmant
Professor of Marine Biology
Center for Marine Science and Dept of Biology and Marine Biology
University of North Carolina Wilmington
5600 Marvin Moss Ln
Wilmington NC 28409 USA
tel:  910-962-2362  fax: 910-962-2410  cell: 910-200-3913

-----Original Message-----
From: coral-list-bounces at coral.aoml.noaa.gov [mailto:coral-list-bounces at coral.aoml.noaa.gov] On Behalf Of Dennis Hubbard
Sent: Tuesday, February 18, 2014 10:24 AM
To: Steve Gittings - NOAA Federal
Cc: coral-list at coral.aoml.noaa.gov
Subject: Re: [Coral-List] fish and algae

Thanks Steve:

This is a possibility I was thinking about when I posted. Do you know of a reference that discusses this. I think that all my HUM-SS students can be made to appreciate the subtlety that exists in well-tuned natural systems such that things "normally" beneficial become more insidious when seemingly unrelated things come into play. If this is actually happening, this is a great demonstration of this idea. We have already talked in class about how the efficiency of well-tuned systems that fiercely recycle and have adapted to do a lot with very little are the most easily perturbed as it take such a small disturbance to disrupt that balance.

There is a growing tension I see in our classes. SS-HUM students self identify as a "non-science type" and translate this into either a defeatist attitude or an opinion that science is not relevant. In contrast NS students bury themselves in a vertical curriculum and view things like environmental and social justice issues as something for someone else to deal with.  I got pretty used to seeing this in students, but am still disappointed when I see it in professional coral-reef scientists and management-oriented colleagues.

In my opinion, this is the NUMBER ONE issue we need to deal with if we are going to resolve all the issues we pontificate about on the listserve. We can argue over divers touching and feeding things and clever ways to package our ideas, but if we forget the student audience by advocating our small piece of intellectual territory, we're going to do even worse that the evolution and climate change community in making any headway. So, thanks to those of you who can help me explain this complex issue to my "non-NS students"..... and especially those geezers among you who still remember when reef scientists talked across disciplines. Sorry for the rant
- it's been a long week.



On Tue, Feb 18, 2014 at 8:34 AM, Steve Gittings - NOAA Federal < steve.gittings at noaa.gov> wrote:

> Dennis,
> Interesting observation.  Perhaps the essence of the "delicate 
> balance" is that, when an ecosystem has it, the natural state enables 
> the ecosystem service  - predators keeping damselfish in check, 
> allowing those surviving ones to tend gardens while keeping  few 
> corals out.  It still leaves plenty of space for other species and 
> interactions, each of which provides its own services.  When out of 
> balance, the natural behaviors, which of course continue, turn what 
> had been an ecosystem service into what can only be considered an 
> "ecosystem disservice" - high damselfish populations inhibiting corals 
> and promoting algae.  In this case, the problem is exacerbated not only by overfishing, but by the *Diadema *dieoff.
> sg
> On Sun, Feb 16, 2014 at 5:56 PM, Dennis Hubbard < 
> dennis.hubbard at oberlin.edu> wrote:
>> When I was a young reef geologist, I was told by most biologists 
>> visiting West Indies Lab that Damselfish "farm" the algal turfs and 
>> actually crop them for maximum yield. As such, they help maintain 
>> this autotrophic system which transforms organic carbon and nutrient 
>> into a form (algal tissue) that can work its way up the food chain. 
>> Walter Adey used turfs to maintain balance in his "microcosms" at the 
>> Smithsonian, has been a valued consultant to aquaria (including the 
>> large GBR tank) and has received patents for "algal scrubbers". So my 
>> sense was that the service provided by both the turfs and the fish 
>> that regulated them is still recognized.
>> I was just looking for photos to shamelessly use for class and came 
>> across an NPR piece (*Tiny Damselfish May Destroy a Ree*f) dated 
>> August 11 in which Richard Harris (who regularly appears on *Morning 
>> Edition* and *All Things Considered*) described a "war going on 
>> between corals and 'a creeping menace'.... algae". This crux of the 
>> story is that parrotfish are the "allies of coral" and 'damselfish 
>> promote algal growth by killing coral to create new space for algal 
>> colonization'. Enter the fishermen who have taken out the predators 
>> who used to "keep the damselfish in check". The result is that 
>> damselfish are disproportionately opening up more space by killing 
>> corals while scaring off the "coral-friendly" parrots by shear 
>> tenacity.
>> Might anyone put this into perspective for me so I don't tell a story 
>> that is no longer true? Each of these points has a ring of truth... 
>> overfishing is real and algae can inhibit coral recruitment. However, 
>> the transformation of damsels from fish "tending their gardens" to 
>> "the primary ally of the creeping manace" seems a bit dramatic. It 
>> also seems to conflate algal turfs (which I understand the damsels 
>> are cultivating) and macroalgae (which can be equally damaging to 
>> both corals and turfs by shading and a host of other pathways).
>> As I hope to get to this in about a week in class, I'd appreciate it 
>> if folks who are closer to this can give me a sense of whether 
>> eradicating algal turfs and the scurrilous damselfish that encourage 
>> them is the new reef paradigm. If there is a place I can send a smart 
>> undergraduate (not necessarily a NS student) to read about this new 
>> balance, that would be even better. What I have read has argued that 
>> there are ties between macro-algal proliferation and both overfishing 
>> and increased nutrient input. While there have been numerous 
>> thoughtful discussions about the details of these interactions, I 
>> have understood that both of these possible linkages are are still 
>> considered to act at some level. I can also imagine a delicate 
>> balance between the benefits of encouraging turfs and clearing space 
>> by chomping on live coral.... and that fishing has impacted this. My 
>> question is whether situation portrayed in this NPR interview is 
>> correct and that the damselfish/turf ralationship shas gon awry to 
>> the point that we need to stop worrying about lionfish and focus on 
>> what I agree is, "pound-for-pound", the meanest fish on the reef.
>> Dennis
>> --
>> Dennis Hubbard
>> Chair, Dept of Geology-Oberlin College Oberlin OH 44074
>> (440) 775-8346
>> * "When you get on the wrong train.... every stop is the wrong stop"*  
>> Benjamin Stein: "*Ludes, A Ballad of the Drug and the Dream*"
>> _______________________________________________
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> --
> Dr. Steve Gittings, Science Coordinator NOAA Office of National Marine 
> Sanctuaries
> 1305 East West Hwy., N/ORM62
> Silver Spring, MD  20910
> (301) 713-7274 (w), (301) 529-1854 (c)

Dennis Hubbard
Chair, Dept of Geology-Oberlin College Oberlin OH 44074
(440) 775-8346

* "When you get on the wrong train.... every stop is the wrong stop"*  Benjamin Stein: "*Ludes, A Ballad of the Drug and the Dream*"
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