[Coral-List] Shark Week!

[Douglas Fenner]

The cause of the decline of reef sharks is of course fishing.  See:

Ward-Page, CA, Mora, C, Lotze HK, Pattengill-Semmens, C, McClenachan, L, et
al.  2010.  Large-scale absence of sharks on reefs in the greater
Caribbean: A footprint of human pressures.  PLoS One 5(8): e11968.
(available open-access for free)

Nadon, M.C., Baum, J.K., Williams, I.D., McPherson, J.M., Zglicynski, B.J.,
Richards, B.L., Schroeder, R.E., Brainard, R.E. Brainard, R.E.  2012.
Re-creating
missing population baselines for Pacific Reef Sharks.  Conservation Biology
26: 493-503.  (available through Google Scholar, just search for the title)

Fishing is well known to usually remove the largest fish first (though
there are exceptions), and that's true for fisheries other than coral reefs
as well as on coral reefs.  The presence or absence of the largest reef
fish is one of the most sensitive indicators of light fishing, since they
are usually removed first, and only extremely remote or super well
protected large areas have the large numbers of such large fish left.
Sharks and goliath grouper (jewfish) in the Caribbean, and in the
Indo-Pacific, sharks, humphead wrasse and bumphead parrots would be some of
the most sensitive indicators of light fishing.  The sizes of the largest
fish that are common is a good general rule-of-thumb indicator of fishing
pressure, if the largest fish are common there is no fishing, if the
largest common fish are 2 feet long and longer there is only light fishing,
if the largest common fish are 1 foot fishing is moderately intense, if the
largest common fish are 6 inches fishing is intense, if the largest are the
size of tea bags then it is super intense.  Something along those lines, it
is far from exact.
     Overfishing is one of the greatest impacts humans have had on coral
reefs.

See:

Fenner, D.  2009.  The largest reef fish species were gone most places in
the world even before scientists knew about it.

www.academia
..edu/2077695/The_Largest_Fish_on_Coral_Reefs_were_the_First_to_Go

Managing reef fisheries is not easy.  For a review, see:

Fenner, D. 2012.  Challenges for managing fisheries on diverse coral reefs.
Diversity 4(1): 105-160.   (available open access)
All four of these articles have lots of references to literature you can
use to learn about these topics.

Cheers,  Doug

On Sun, Aug 11, 2013 at 7:05 AM, Chelsie Counsell <cwagner at bio.fsu.edu>wrote:

> Hi Mark,
>
> When I spent semesters in South Caicos in 2008 and 2010, sharks were still
> practically a guarantee when diving the channels and drop offs. Mainly reef
> sharks with some lemons and the very occasional hammerhead.
>
> Best,
> Chelsie Counsell
>
> --
> NSF Graduate Fellow
> Department of Marine Biology
> University of Hawai'i
> counsell at hawaii.edu
>
> Date: Fri, 9 Aug 2013 09:16:39 -0700
> > From: Mark Tupper <mtupper at coastal-resources.org>
> > Subject: Re: [Coral-List] Shark week!
> > To: "Pawlik, Joseph" <pawlikj at uncw.edu>
> > Cc: "coral-list at coral.aoml.noaa.gov" <coral-list at coral.aoml.noaa.gov>
> > Message-ID:
> >         <F40A06B4-CAA6-4643-9595-130EE0FE1248 at coastal-resources.org>
> > Content-Type: text/plain;       charset=us-ascii
> >
> > Hi Joseph,
> >
> > Have you been working in the Exumas for some time? I ask because I lived
> > there in 1988 and 89 and back then, shark encounters wouldn't make the
> > news. Sharks were very common - to the point that spearfishing could be
> > risky, as sharks were encountered on many dives, if not most. I guess
> that
> > is no longer true?
> >
> > Also, as late as 2000, sharks were almost guaranteed when diving channels
> > and drop offs  around South Caicos in the TCI. Not sure if that is still
> > true 13 years later...
> >
> > Cheers
> > Mark Tupper
> >
> >
> >
> > On 2013-08-09, at 7:03 AM, "Pawlik, Joseph" <pawlikj at uncw.edu> wrote:
> >
> > > Hi Listers,
> > >
> > > In keeping with Discovery Channel's "Shark week" (minus the Megalodon
> > hoax), check out this video of reef sharks from a site within the Exuma
> > Land and Sea Park in the Bahamas.  We rarely see sharks while diving on
> > reefs in the Caribbean, and then usually only as fleeting glimpses in the
> > distance.  But at both visits to this site, a few small reef sharks
> slowly
> > circled the divers.  I suspect that other dive groups feed these sharks
> (we
> > do not).
> > > http://youtu.be/MzrWACzMFZ8
> > > Regards,
> > >
> > > Joe
> > > **************************************************************
> > > Joseph R. Pawlik, Professor
> > > UNCW Center for Marine Science
> > > 5600 Marvin K Moss Lane
> > > Wilmington, NC  28409   USA
> > > pawlikj at uncw.edu<mailto:pawlikj at uncw.edu>; Office:(910)962-2377; Cell:
> > (910)232-3579
> > > Website: http://people.uncw.edu/pawlikj/index.html
> > > PDFs: http://people.uncw.edu/pawlikj/pubs2.html
> > > **************************************************************
> > >
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