Coral Harvesting - Fiji.

EricHugo at EricHugo at
Fri Aug 6 09:51:23 EDT 1999

In a message dated 8/6/99 6:30:24 AM, JSprung at writes:

<< The live rock harvested from
Fiji is composed of and constructed mostly by coralline algae. There is
some Montipora, Leptastrea, Psammocora and Porites among it, but the
majority throughout is just coralline algae. So, figures of "how many tons
of live rock" do not equal how much coral. I would estimate that the rock
is not more than 10% coral by weight, probably much less. >>

Hi Julian:

The concern I have is not merely for the presence of scleractinia but as a 
general loss of habitat.  This live rock provides important spatial 
heterogeneity for a huge number of organisms.  the number of organisms in 1 
cubic meter of "live rock" has been estimated at over 1,000,000 organisms.  
While "rubble zones" may not provide a good site for the long term survival 
of juvenile coral settlement, the habitat does provide for both hard and soft 
substrate flora and fauna which is part of the ecosystem.  Scleractinia are 
typically the focus of ENSO events and are the most "colorful" items to 
report to media sources. Far fewer studies, if any, are done to assess the 
impact of collection on, say, various coelobites. Or the relative effects of 
mass bleaching events or high SST's on photosynthetic subsurface flora and 
fauna.  What discourages me most is the reckless abandon with which such live 
rock substrate is handled following collection. This has gotten much worse 
over recent years as availability has increased and prices dropped 
dramatically. The rock is nearly dry and sits unsubmerged for a week or more 
before arriving to a facility which then "cures" it - be it wholesale, retail 
or consumer level.  At this point, only a smattering of the original life 
remains, and even much of the coralline algae is lost.  The low prices of 
this substrate (and, for that matter, wild collected corals and fish) has 
also put an extreme economic disadvantage to those who are aquaculturing live 
rock and working towards creating a sustainable industry.  

<<On the subject of weight, the live rock is wet, so the weights quoted
include quite a bit of water. That should be considered too.

The weight of water may also be a factor in "tonnage" of live corals
reported, as they are typically shipped submerged in a bag of water,
suspended by a styrofoam float. The figures for live corals should be
reported as number of pieces, not weight.>>

The numbers I quoted in the other reponse are by piece and not weight. 

<<This represents a completely
renewable resource and a viable industry for Fiji,>>

I don't think there is enough data available, especially given the stresses 
present on reefs today, to accurately assess what comprises "completely 
renewable", much less "viable."

<<What I do not know is the growth rate of these coralline
stones, so I cannot comment on the level of harvest that can be termed
sustainable. >>

Given that the rubble zones have material originating from reef zones which 
are periodically buried and then uncovered, as well as added to as storms 
break off other pieces of reef material and are acted on by large bioerosive 
and mechanical forces - and that one must consider the total flora and fauna, 
not just the growth rate of surface growing crustose corallines, I don't 
think it likely that sustainable levels will be easily determined.  What 
seems to be a more valid question is the necessity of tons of wild living 
substrate being virtually killed to provide substrate for aquaria. I am an 
aquarist, and I even partially earn my income from the hobby through my 
writings, and clearly recognize the *potential* of the private sector to 
provide important information in terms of observations and husbandry of 
marine organisms.   However, so long as the economics of mass export of cheap 
, poorly handled, wild collected material prevents carefully managed, 
non-destructive and sustainable aquaculture from becoming the source for such 
large amounts of reef biota, it is very hard to rationalize its continuance.  
I think viable economic alternatives must be put into place immediately, if 
not sooner, given the status of the world's reefs,

Eric Borneman

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