Byrd et at: Standings as indicators of marine mammal biodiversity and human interactions 
13 
(16 odontocete species; Maldini et al., 2005), San Diego, 
California (24 cetacean species along 125 km, Danil 
et al., 2010), southeastern Canada (19 cetacean spe- 
cies, Nemiroff et al., 2010), and Cape Cod-southeastern 
Massachusetts (16 marine mammal species along 1126 
km, Bogomolni et al., 2010). An exception is Western 
Australia where 34 cetacean species were found, but 
the study encompassed 12,889 km of coastline and 
roughly 20 degrees of latitude (Groom and Coughran, 
2012). The high diversity found in NC emanates from 
multiple oceanographic features and the resulting 2 
converging biogeographic zones off the coast. These 
findings may also reflect shifting distribution patterns 
over time that are indicative of climate change (e.g., 
MacLeod et al., 2005, Johnston et al., 2012). 
A comparison of strandings to published records of 
live animals indicates that generally the most numer- 
ous stranded species inhabit nearshore waters, are 
very abundant, or both. Coastal bottlenose dolphins 
are the most abundant species nearshore, although 
their abundance varies seasonally (-1000-13,000 ani- 
mals; Waring et al., 2010). Harbor porpoises and har- 
bor seals generally inhabit coastal waters during at 
least part of the year (Bigg, 1981; Palka et al., 1996), 
although they are only seasonally present off NC and 
their local abundances and distribution are unknown. 
Relative stranding frequencies of pelagic delphinids 
generally reflect relative abundance during aerial and 
shipboard surveys (Waring et al., 2007). This is par- 
ticularly interesting for species for which NC is their 
southern distribution (e.g., common dolphins, striped 
dolphins, Atlantic white-sided dolphins) (Waring et 
al., 2007). During summer surveys outside of the 10-m 
isobath along the mid-Atlantic coast of the United 
States, the most commonly sighted species were off- 
shore bottlenose dolphins, sperm whales, Atlantic 
spotted dolphins and Risso’s dolphins (Mullin and 
Fulling, 2003), and all of these species, except sperm 
whales, were quite often found stranded. In contrast, 
the prevalence of Kogia strandings is disproportionate 
to their relatively low population size estimate (pygmy 
sperm whales, n=741; dwarf sperm whales, rc=1042) 
and pelagic distribution (Waring et al., 2013). This 
incongruity between stranding levels and population 
sizes for kogiids has been reported elsewhere (Maldini 
et al., 2005), and is likely due, in part, to population 
estimates that are underestimated owing to availabil- 
ity and perception bias during surveys (Barlow, 1999). 
Gervais’ beaked whales ( Mesoplodon europaeus) were 
also commonly stranded in this study, consistent with 
previous reports of this species stranding along the 
U.S. Atlantic coast (Waring et al., 2009a). As with Ko- 
gia species, the number of strandings is disproportion- 
ate to the low abundance estimate ( Mesoplodon spp. 
and Ziphius spp. combined; n=3513; CV=0.63) (War- 
ing et al., 2009a), and the species are also subject to 
the same detection biases during surveys. Some spe- 
cies (e.g., melon-headed whales, pygmy killer whales, 
false killer whales) that are rarely seen in the west- 
ern North Atlantic (Mullin and Fulling, 2003; Waring 
et al., 2007) were also uncommon in the stranding 
record. 
o < A > <- — — — ±±z — Q • ' >< A " ■ > 
10-km section 
Figure 5 
Mean annual stranding events by 10-km section within coastal segments (A-D) from the 
Virginia/North Carolina (NC) border (section 1) to the NC/South Carolina border (section 
54; section=7.6 km) during 1997-2008. Graph shows coastal bottlenose dolphin ( Tursiops 
truncatus) (white bars; n= 855) separate from all other species (black bars; n= 702). Vertical 
dotted lines indicate the areas of the 3 NC capes (Hatteras, Lookout, Fear) and divide the 
coastline into 4 segments: A, B, C, D. 
