[Coral-List] fish and algae

Fautin, Daphne G. fautin at ku.edu
Wed Feb 19 12:17:00 EST 2014


Colleagues,

Another Indo-WP damselfish that is at least charismatic, if not ecologically essential, is the anemonefish.  They do not tend the gardens of the damselfishes mentioned here.  My observation, recorded in a paper published in the proceedings of CRS 6 (Fautin, 1989, Proceedings of the Sixth International Coral Reef Symposium 3: 231-236) and reinforced by findings published last year (Fautin et al., 2013, Biological Bulletin 224: 89-98) is that where scleractinian corals are diverse and occupy much space, sea anemones (in general -- but most obviously those that host anemonefishes) are few and far between; most of the reef areas on which I did research on anemonefishes were grungy (only half the species of anemonefishes actually live on reefs -- the other half are associated with seagrass beds, sandflats, etc. that may occur around reefs, but some can live far from reefs, their image notwithstanding).  So the colorful, coral-dominated reefs may lack some of the elements that are seen as characteristic of reefs.  Clearly, the old idea of a climax community means that in one, members of earlier stages of succession are absent or at least scarce.  Stability requires a patchwork.  I am not arguing for grungy reefs -- one needs habitats at all stages of succession for maximum diversity.  But there is a role for grunge.

By the way, PDFs of these and most of my publications are available on my home page (URL below).


Daphne G. Fautin
Professor, Ecology and Evolutionary Biology
Curator, Natural History Museum (Biodiversity Institute)
University of Kansas
1200 Sunnyside Avenue
Lawrence, Kansas 66045 USA

telephone 1-785-864-3062
fax 1-785-864-5321
skype user name daphne.fautin
evo user name fautin
website: invertebratezoology.biodiversity.ku.edu/home
cv: www.nhm.ku.edu/inverts/daphne.html

    database of hexacorals, including sea anemones
       newest version released 2 January 2013
hercules.kgs.ku.edu/Hexacoral/Anemone2/index.cfm

________________________________________
From: coral-list-bounces at coral.aoml.noaa.gov [coral-list-bounces at coral.aoml..noaa.gov] on behalf of Nicole Crane [nicrane at cabrillo.edu]
Sent: Tuesday, February 18, 2014 5:21 PM
To: coral-list at coral.aoml.noaa.gov
Subject: Re: [Coral-List] fish and algae

This is a great discussion, and I felt inclined to weigh in.  We've been
surveying reefs in Micronesia, and while we have quantitative data sets,
we didn't look specifically at damselfish, so I'm afraid I have no
empirical evidence for the following observation (other than having
looked at many reefs):
The 'healthiest' reefs we see (high coral morphology diversity, high
cover, high biomass and diversity of fish etc.), are places where I see
damselfish (on shallow flats) and their 'gardens'.  The more degraded
reefs seem to have far fewer of them (I'll mention that Acropora is
harvested from some reefs for the lime that is chewed with beetlenut).
Not that this bolsters any specific argument, but I am reminded of how
we need to be careful to make sensational, simplistic stories from a
complex stage.  I am reminded of the African Elephant who has long been
blamed for their destructive eating habits and the negative impacts on
acacia trees (an ecosystem disservice?).  Yet, by eating the seed pods
of certain acacias, they sterilize the seeds, protecting them from
certain death from a parasitic grub that will otherwise kill them.  Upon
defecation on to the fertile grassland soil, a very high percentage of
these seeds will germinate (an ecosystem service?).

Thus the charismatic mesofaunal damselfish (to distinguish it from the
marine megafaunal superstars) probably has a complicated story behind
it.  Steve said it well!

Maybe its our responsibility in part to make sure that when these
stories are told in a public forum, simplification and sensationalism is
really not necessary - the whole story is really the interesting one.

Nicole


On 2/18/14, 10:34 PM, Steve Gittings - NOAA Federal 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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>>
>
>

--
Nicole L. Crane
Cabrillo College
Division of Natural and Applied Sciences
831-479-5094
nicrane at cabrillo.edu
www.cabrillo.edu/~ncrane

Oceanic Society
Senior Conservation Scientist
www.oceanicsociety.org

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