Kyne & Simpfendorfer.. - Shark Specialist Group

BIOGEOGRAPHY
A broad-scale analysis of the biogeographical distribution of deepwater chondrichthyans
reveals the highest levels of diversity in the Indo-West Pacific (Table 1.2). The Western and
Eastern Atlantic have similar numbers of species, while diversity is lower in the Eastern
Pacific. The Arctic and Antarctic regions are depauperate in terms of deepsea fauna. These
biogeographical patterns follow general trends of chondrichthyan biogeography and diversity
(Musick et al. 2004). The Indo-West Pacific is a large ocean region with a high level of
endemism and thus it is not surprising that the highest diversity is recorded there. Lower
diversity in the Eastern Pacific is attributable to a general lack of squaloid sharks, as
previously recognised by Musick et al. (2004). Table 1.3 displays diversity by FAO Fisheries
Areas (the United Nation's Food and Agriculture Organization's Major Fishing Areas for
Statistical Purposes - maps of these can be located at
ftp://ftp.fao.org/fi/maps/Default.htm#CURRENT), again illustrating high diversity in
Fisheries Areas constituting the Indo-West Pacific, as well as in the Western Central Atlantic,
a region centred around the tropical Caribbean Sea. (In Tables 1.2 and 1.3 the sum of totals
exceeds the known number of deepwater species (581) as wider-ranging species occur in
more than one region or Fisheries Area).
Table 1.2. Deepwater chondrichthyan diversity by major ocean region*.
Ocean region Sharks Batoids Holocephalans Total
Arctic Sea 1 0 0 1
Indo-West Pacific 190 123 28 341
Eastern Pacific 49 41 8 98
Western Atlantic 73 70 8 151
Eastern Atlantic 72 58 12 142
Antarctic seas 1 7 1 9
*Arctic Sea (FAO Area 18); Indo-West Pacific (FAO Areas 51, 57, 61, 71, 81); Eastern Pacific (FAO
Areas 67, 77, 87); Western Atlantic (FAO Areas 21, 31, 41); Eastern Atlantic (FAO Areas 27, 34, 37,
47); Antarctic seas (FAO Areas 48, 58, 88).
Table 1.3. Deepwater chondrichthyan diversity by FAO Fisheries Area.
FAO Fisheries Area Sharks Batoids Holocephalans Total
18 Arctic Sea 1 0 0 1
21 Northwest Atlantic 18 13 3 34
27 Northeast Atlantic 42 23 8 73
31 Western Central Atlantic 59 37 5 101
34 Eastern Central Atlantic 44 21 7 72
37 Mediterranean and Black Sea 19 9 1 29
41 Southwest Atlantic 26 27 3 56
47 Southeast Atlantic 48 25 6 79
48 Antarctic Atlantic 0 4 1 5
51 Western Indian Ocean 68 27 5 100
57 Eastern Indian Ocean 71 32 13 116
58 Antarctic Indian Ocean 1 5 0 6
61 Northwest Pacific 81 37 10 128
67 Northeast Pacific 4 14 1 19
71 Western Central Pacific 79 26 9 114
77 Eastern Central Pacific 32 16 3 51
81 Southwest Pacific 54 39 16 109
87 Southeast Pacific 30 24 5 59
88 Antarctic Pacific 0 2 0 2
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