[Coral-List] reef fish and algae
andyroo_of72 at yahoo.com
Fri Feb 21 11:14:05 EST 2014
Peter and list,
A few quick notes and damsel garden observations:
In '05-'06, I did 50 x 314m2 radial transects around Montego Bay, Jamaica, looking specifically for and at Acropora cervicornis. There were found quite a few, mostly independent and well on the small side (<20cm total branch length). We did not find one sexual recruit in these plots, though I have seen a couple over the years.
Every colony encountered (save one) that was bigger than a football/soccer-ball had at least one damsel nesting in it. In fairness, Montego Bay is thick with three-spot damsels, which may be linked to the lack of predators and/or tourist boats feeding them bread. Preferred habitat corals are certainly in short supply.
For damsel gardening's impact, the process appeared to be that a coral would get to the right size/quality and a damsel would move in and nick out a bit in the middle for his garden. Eventually, either through facilitation or more active vectoring, this would progress into a banding syndrome that would move up and outwards along the nested branch(es). This disease would usually leave the branch ends alive, but likely too small to spawn. We found a strong correlation between nesting activities and disease, and I speculated that this process was the primary reason why the bay's corals were so small. Austin Bowden-Kerby talked about this damsel-disease process in '04.
Yes, for coral gardening programmes we incorporate removal of any damsels that are actively making nests to i) reduce the immediate damage and ii) reduce chance for larger disease outbreak. This is on discrete garden scales, thus not more than a hectare and only on corals that we've put in. As they (damsels) are quick & bright, the guys have developed a little short-shot speargun with two ping-pong-balls with pupil dots mounted on the front to bring on the attack mode- zap. Apparently they're very oily and have a hint of bacon flavour on the BBQ. Local name is "black-hog"
On Thursday, February 20, 2014 7:16 AM, Peter Sale <sale at uwindsor.ca> wrote:
Denny and others,
I've been following the reminiscences and other stories re damselfishes,
algae, coral and Caribbean decline with interest. Lots of good comments
buried in that thread.
I hope nobody has missed the hubris and irony in the fact that having done
a number of things that have resulted in the massive decline most parts of
the Caribbean (and many reefs elsewhere) are experiencing, we are now
focusing on the activities of tiny, if pugnacious, little damselfishes
that happen to like algal turfs, and do cause marginal damage to living
corals in 'cultivating' their gardens. The particular thread haws not
gone there yet, but I can imagine someone less wise getting hold of these
comments and advocating for a massive cull of three-spots in order to save
sale at uwindsor.ca
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