Not just a
huge collection of
Elasmodiver.com contains images of sharks, skates, rays, and a few
chimaera's from around the world. Elasmodiver began as a simple web
to help divers find the best places to encounter the different
species of sharks and rays that live in shallow water but it has
slowly evolved into a much larger project containing information on
all aspects of shark diving and shark photography.
now more than 10,000 shark pictures and sections on shark
evolution, biology, and conservation. There is a large library of
reviewed shark books, a constantly updated shark taxonomy page, a
monster list of shark links, and deeper in the site there are
numerous articles and stories about shark encounters. Elasmodiver is
now so difficult to check for updates, that new information and
pictures are listed on an Elasmodiver Updates Page that can be
rounded snout with sharp leading edge. First dorsal fin originates behind
pectoral axis. Dorsal pointed. Pectoral fins slightly sickle shaped dusky tips on underside. Low interdorsal ridge present.
Low second dorsal and anal fin usually have dusky tips. Pectoral and pelvic fins
can also have dusky tips. Well developed caudal fin with dusky trailing edge. Body fairly
monochrome greyish brown above and pale below.
length 4.2m. 70
to 100cm at birth.
Usually found around continental
coastlines. To 400m depth.
Circumtropical on continental shelves.
Behavior:Feeds actively during the day. Diet includes: Bony fishes, other
sharks and rays, and some crustaceans and mollusks.
Litter size 3 - 14. Uses shallow water regions for nursery grounds.
Conservation Status: Listed as VULNERABLE by the IUCN.
sharks are taken as both bycatch and target in commercial shark
fisheries using, set nets, longlines, hook and line and trawls
(Cramer 1995, Compagno in prep.) in many areas of its range. The
species has among the most sought after fins for shark fin soup
because of their large size and high fin needle content (ceratotrichia)
(TRAFFIC 1996, R. Hudson pers. comm.). Because of its high-value
fin, dusky sharks caught incidentally in tuna and swordfish
fisheries are now regularly landed rather than released. Carcharhinus
found to represent at least 1.2-1.7% of the fins auctioned in Hong
Kong, the world's largest shark fin trading center (Clarke et
2006a). It is estimated that between 144,000 and 767,000 Dusky
Sharks are represented in the shark fin trade each year or, in
biomass, 6,000 to 30,000 mt (Clarke et
The very low intrinsic rate of increase of the Dusky Shark renders
this species among the most vulnerable of all vertebrates (including
great whales and sea turtles) to man-induced mortality (Compagno et
2005, Musick 1999). Furthermore, Compagno et
(2005) report that the species is difficult to manage or protect
because it is taken in mixed species fisheries, and has a high
mortality rate when taken as bycatch.
Further threats to C.
from beach meshing programs in Australia and South Africa and from
recreational fishing. Beach meshing in Australia (Queensland and
News South Wales) undoubtedly catches C.
however, species-specific data are not available. Between 1972 and
1990, the New South Wales program caught a total of 765 whaler
sharks (Reid and Krough 1992), of which Stevens (1984) reported the
capture of larger juvenile and adult C.
recreational fishers off the east coast of Australia.
were one of the most important species in the trophy shark
tournaments held in Florida, USA, until the stock collapsed (Heuter
After baiting Dusky Sharks in an
area for one afternoon the boat returned to port. The next day the same easily
recognizable Dusky Sharks were able to find the boat and join the feed within a
few minutes even though it had relocated to another sea mount.
Port Saint Johns, Wild Coast, South Africa.
Taken during the annual Sardine Run.
Reaction to divers:
In baited situations Duskies can become very aggressive. While snorkelling near
the bait I observed them trying to bite my fins whenever my kicking speed
increased. They are easily excited and their large size makes them potentially
very dangerous. However, outside of baited situations it is very difficult to
find Duskies while diving. Dusky sharks have been known to repeatedly attack
logistics: Dusky sharks regularly
show up to feed on bait balls during the annual 'Sardine Run' in South Africa.
Big Fish Expeditions runs
Sardine Run Shark Diving Trips
during which they also chum for sharks. Duskies are one of the main species that
show up during the chumming sessions.
Musick, J.A., Grubbs, R.D., Baum, J. & Cortés, E. 2009. Carcharhinus
The IUCN Red List of Threatened Species 2009: e.T3852A10127245. http://dx.doi.org/10.2305/IUCN.UK.2009-2.RLTS.T3852A10127245.en. Downloaded