Strandings as indicators of marine mammal 
biodiversity and human interactions off the 
coast of North Carolina 
Abstract— The adjacency of 2 marine 
biogeographic regions off Cape Hat- 
teras, North Carolina (NC), and the 
proximity of the Gulf Stream result 
in a high biodiversity of species from 
northern and southern provinces and 
from coastal and pelagic habitats. We 
examined spatiotemporal patterns of 
marine mammal strandings and evi- 
dence of human interaction for these 
strandings along NC shorelines and 
evaluated whether the spatiotemporal 
patterns and species diversity of the 
stranded animals reflected published 
records of populations in NC waters. 
During the period of 1997-2008, 1847 
stranded animals were documented 
from 1777 reported events. These 
animals represented 9 families and 
34 species that ranged from tropical 
delphinids to pagophilic seals. This bio- 
diversity is higher than levels observed 
in other regions. Most strandings were 
of coastal bottlenose dolphins (Thrsiops 
tru/icatus) (56%), harbor porpoises 
(Phocoena phocoena) (14%), and harbor 
seals ( Phoca vitulina) (4%). Overall, 
strandings of northern species peaked 
in spring Bottlenose dolphin strand- 
ings peaked in spring and fall. Al- 
most half of the strandings, including 
southern delphinids, occurred north 
of Cape Hatteras, on only 30% of NC’s 
coastline. Most stranded animals that 
were positive for human interaction 
showed evidence of having been en- 
tangled in fishing gear, particularly 
bottlenose dolphins, harbor porpoises, 
short-finned pilot whales ( Globicepha - 
la macrorhynchus), harbor seals, and 
humpback whales ( Megaptera novae- 
angliae). Spatiotemporal patterns of 
bottlenose dolphin strandings were 
similar to ocean gillnet fishing effort. 
Biodiversity of the animals stranded 
on the beaches reflected biodiversity 
in the waters off NC, albeit not always 
proportional to the relative abundance 
of species (e.g., Kogia species). Chang- 
es in the spatiotemporal patterns of 
strandings can serve as indicators of 
underlying changes due to anthropo- 
genic or naturally occurring events in 
the source populations. 
Manuscript submitted 8 February 2013. 
Manuscript accepted 1 November 2013. 
Fish. Bull. 112:1-23 (2014). 
doi: 10.7755/FB.112.1.1 
The views and opinions expressed or 
implied in this article are those of the 
author (or authors) and do not necesarily 
reflect the position of the National 
Marine Fisheries Service, NOAA. 
Barbie L. Byrd 1 (contact author) 
Aleta A. Hohn 1 
Gretchen N. Lovewell 1 
Karen M. Altman 1 
Susan G. Barco 2 
Ari Friedlaender 3 
1 Southeast Fisheries Science Center 
National Marine Fisheries Service, NOAA 
101 Pivers Island Road 
Beaufort, North Carolina 28516 
2 Virginia Aquarium & Marine Science Center 
Foundation 
717 General Booth Boulevard 
Virginia Beach, Virginia 23451 
3 University of North Carolina Wilmington 
601 South College Road 
Wilmington, North Carolina 28403 
Marine biogeographic boundaries 
are remarkable 1) for the diversity 
of species that occur as a result of 
the biogeographically distinct prov- 
inces on either side of the environ- 
mental or dispersal discontinuities 
(e.g., Ekman, 1953; Searles, 1984) 
and 2) for the long-term influences 
of these boundaries on phylogeog- 
raphy (e.g., Wares et ah, 2001; Ad- 
ams and Rosel, 2006). Several ma- 
rine biogeographic boundaries oc- 
cur along the continental United 
States, such as at Point Concep- 
tion, California; Cape Canaveral, 
Florida; Cape Cod, Massachusetts; 
and Cape Hatteras, North Carolina 
(NC) (Briggs, 1974; Fautin et al., 
2010). The faunal transition zone 
at Cape Hatteras results from the 
juxtaposition of warm waters from 
the northeast-flowing Gulf Stream 
and cool waters from the south- 
flowing Virginia Current and leads 
to the occurrence of both temperate 
Craig A. Harms 4 
William A. McLellan 3 
Kathleen T. Moore 1 
Patricia E. Rosel 5 
Victoria G. Thayer 6 
4 Center for Marine Sciences and Technology 
and Department of Clinical Sciences 
College of Veterinary Medicine 
North Carolina State University 
303 College Circle 
Morehead City, North Carolina 28557 
5 Southeast Fisheries Science Center 
National Marine Fisheries Service, NOAA 
646 Cajundome Boulevard 
Lafayette, Louisiana 70506-4291 
6 Duke University Marine Laboratory 
135 Duke Marine Lab Road 
Beaufort, North Carolina 28516 
and subtropical-tropical species of 
algae (Searles, 1984), invertebrates 
(Cerame-Vivas and Gray, 1966; 
Baker et al., 2008), ichthyoplankton 
(Grothues and Cowen, 1999), and 
fishes (Schwartz, 1989) along the 
NC coast. In addition to the biogeo- 
graphic boundary at Cape Hatteras, 
the Cape is the closest point of 
land to the Gulf Stream along the 
mid-Atlantic coast (Briggs, 1974), 
concentrating pelagic fauna rela- 
tively close to shore. Many fish spe- 
cies occurring in NC waters are es- 
tuarine-dependent coastal migratory 
species from northern and southern 
biogeographic provinces (Ray et al., 
1997), taking advantage of NC es- 
tuaries, the second largest estuary 
system in the continental United 
States (Paerl et al., 2001). 
The conditions described previous- 
ly create an environment conducive 
for productive commercial (Steve et 
al., 2001) and recreational fisheries 
Email address for contact author: barbie.byrd@noaa.gov 
