[Coral-List] From Les Kaufman re: damselfish, algae, coral, and the meaning of life

Kaufman, Leslie S lesk at bu.edu
Tue Feb 18 12:35:49 EST 2014


Hi all.  Bill Precht has been in touch with Dennis offline to remind him of our 2010 PLoS One paper that goes into some of the subtleties of the damselfish-algal-coral relationship.

Shameless promotion here:

Precht, W.F., R.B. Aronson, R.M. Moody and L. Kaufman. 2010. Changing patterns of
microhabitat utilization by the threespot damselfish, Stegastes planifrons, on Caribbean
reefs. 2010. PLoS ONE, 2010: 5(5): e10835 DOI:10.1371/journal.pone.0010835.

Dennis it is interesting that you used the term "insidious" because I now refer to the damselfish-coral relationship as the archetype of a class of interactions I like to call "insidious symbioses", i.e., a symbiotic relationship that can slide from parasitism to commensalism to mutualism and back contingent upon the relative densities of host, inquiline, and environmental factors such as grazing and predation pressure.  There is actually something of a literature on the protean nature of symbioses.  A familiar example is the concave fitness set for pathogens between high vs. low lethality, with the switch between these two well-differentiated life history strategies contingent upon host density.

For many years I had firmly rejected the notion that the abundance of algal-gardening damselfish was regulated by predators, rather than habitat.  Then Mark Vermeij got a hold of me.  I"m still not convinced that a there is a predation intensity effect on algal lawn density in primary habitat (A. cervicornis), but there could well be interesting effects on total damselfish density (meaning here, Stegastes planifrons)  with effects concentrated on secondary and juvenile habitats.  There is ample annecdotal evidence that threespots worry themselves about being eaten even when in good habitat: e.g., the apparent prevalence of very small individuals with fully adult coloration and behavior on habitats of small spatial scale, such as isolated lagoonal mounds of Porites porities/furcata.  That is, you don't see individuals that would have difficulty vanishing into the available scale of refugium structures.  They are brazen little buggers but they aren't idiots.

We are getting wound up now about looking at the branching-massive-damselfish dynamic in Florida and Belize, with a focus on Acropora cervicornis and Orbicella annularis.  Glad folks are still interested!

Oh yeah, sorry, the meaning of life.

42

Les


Les Kaufman
Professor of Biology
Boston University Marine Program
and
Marine Conservation Fellow
Betty and Gordon Moore Center for Ecosystem Science and Economics
Conservation International
lesk at bu.edu<mailto:lesk at bu.edu>



Message: 1
Date: Tue, 18 Feb 2014 10:23:36 -0500
From: Dennis Hubbard <dennis.hubbard at oberlin.edu<mailto:dennis.hubbard at oberlin.edu>>
Subject: Re: [Coral-List] fish and algae
To: Steve Gittings - NOAA Federal <steve.gittings at noaa.gov<mailto:steve.gittings at noaa.gov>>
Cc: "coral-list at coral.aoml.noaa.gov<mailto:coral-list at coral.aoml.noaa.gov>" <coral-list at coral.aoml.noaa.gov<mailto:coral-list at coral.aoml.noaa.gov>>
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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.

Dennis

Denni


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


------------------------------

Message: 2
Date: Tue, 18 Feb 2014 10:28:54 -0500
From: "Szmant, Alina" <szmanta at uncw.edu<mailto:szmanta at uncw.edu>>
Subject: Re: [Coral-List] fish and algae
To: Bill Allison <allison.billiam at gmail.com<mailto:allison.billiam at gmail.com>>, Dennis Hubbard
<dennis.hubbard at oberlin.edu<mailto:dennis.hubbard at oberlin.edu>>
Cc: "coral-list at coral.aoml.noaa.gov<mailto:coral-list at coral.aoml.noaa.gov>" <coral-list at coral.aoml.noaa.gov<mailto:coral-list at coral.aoml.noaa.gov>>
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<68ECDB295FC42D4C98B223E75A854025DA9353166E at uncwexmb2.dcs.uncw.edu<mailto:68ECDB295FC42D4C98B223E75A854025DA9353166E at uncwexmb2.dcs.uncw.edu>>
Content-Type: text/plain; charset="us-ascii"

Margaret Miller and I looked at damselfish effects on large coral heads back in later 1990s.  Very large Montastraea faveolata heads (now Orbicella) had pretty significant damselfish laws up on the tops and sides of colonies that were many hundreds of years old.  Those colonies would obviously not have grown to those sizes with large lawns on their upper surfaces, thus this was a new issue for those colonies.  Our hypothesis was that lack of predation was allowing the damsels (mostly 3 spot) to be brave and have their lawns up in the reef penthouses instead of hiding in clumps of A. cervicornis where they were formerly abundant, but we really had no way to actually test that.  I saw similar problems in La Parguera with tops of coral heads including large Dendrogyras all colonized by damsels and also Echinometra (boring urchins that basically ground down these coral heads to sand and silt).

The question is whether these fish and urchins were more abundant that in the good ol' days because of continued over fishing over the decades, whether the damsels moved from branching coral hide outs to  reef pent-house real estate because of the loss of the branching coral coupled with lower demise rate due to predation if their lawns are more exposed, or some additional/other issue affecting damsel fish abundance.  In my mind, looking back over 40 years of PR diving, and 30 years in the FL Keys,  these lawns are more abundant and more exposed than when my attention was first drawn to them by Les Kaufman's work.


"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
http://people.uncw.edu/szmanta
*******************************************************


-----Original Message-----
From: coral-list-bounces at coral.aoml.noaa.gov [mailto:coral-list-bounces at coral.aoml.noaa.gov] On Behalf Of Bill Allison
Sent: Tuesday, February 18, 2014 8:07 AM
To: Dennis Hubbard
Cc: coral-list at coral.aoml.noaa.gov
Subject: Re: [Coral-List] fish and algae

Hi Dennis,

No doubt damsels kill coral. As you suggest, it is most likely that
underlying causes such as bleaching, pollution, and overfishing tilt the
playing field too allow more coral destruction, or less construction, or
both, but it's much more satisfying spiritually and economically to have a
critter to blame and kill, non?

On several reefs that I have surveyed over time corals survived only in
Stegastes nigricans territories after repeat COT outbreaks (I also noticed
coral survival in damsel territories after the 1998 bleaching). During the
second COT outbreak all the preferred COT prey were gone and the COT were
eating whatever was left. Some coral colonies within but near the periphery
of S. nigricans territories were damaged along their outer edges but apart
from that, corals in S. nigricans territories survived these invasions
unscathed. I am not the first to have noticed this (e.g., Glynn and Colgan,
1988)

Glynn, P. W. and M. W. Colgan (1988). "Defense of corals and enhancement of
coral diversity by territorial damselfish." Proc. 6th ICRS, Townsville 2:
157-164.








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*"
_______________________________________________
Coral-List mailing list
Coral-List at coral.aoml.noaa.gov
http://coral.aoml.noaa.gov/mailman/listinfo/coral-list




--
"... the earth is, always has been, and always will be more beautiful than
it is useful." - Ophuls, 1977
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