9 
National Marine 
Spencer F. Baird 
r\ 
Fisheries Service 
Fishery Bulletin 
First U S Commissioner 
M 
NOAA 
fa- established in 1881 -d> 
of Fishery Bulletin I 
w 
Environmental and spatial preferences of dolphinfish 
(Coryphaena spp.) in the eastern Pacific Ocean off 
the coast of Mexico 
Email address for contact author: amuhlia04@cibnor.mx 
Centro de Investigaciones Biologicas del Noroeste, Sodedad Civil 
Avenida Instituto Politecnico Nacional 195 
Colonia Playa Palo de Santa Rita 
23096 La Paz, Baja California Sur, Mexico 
Abstract-— The main objective for 
this study was to provide informa¬ 
tion on the relationship between dol¬ 
phinfish (Coryphaena spp.) catches 
and the environmental conditions, 
which could help to explain dol¬ 
phinfish movements in the eastern 
tropical Pacific Ocean off the coast 
of Mexico—a topic that is still un¬ 
der debate. We analyzed a 10-year 
(2004-2013) database of estimated 
incidental catch from the Inter- 
American Tropical Tuna Commis¬ 
sion, reported by observers on board 
tuna purse-seine ships. Significant 
seasonal and interannual differences 
were found in the incidental catch. 
No segregation due to size was ap¬ 
parent. Two areas of high catch were 
present in the study zone: one near 
the Baja California Peninsula that 
is especially productive during sum¬ 
mer, and a second in an oceanic area 
(~15°N, 120°W), which is present all 
year long but becomes more impor¬ 
tant during May-June. Using satel¬ 
lite images, we found that the 2 spe¬ 
cies of dolphinfish preferred warm 
waters (24-28°C) with low concen¬ 
trations of chlorophyll-a (<0.02 mg/ 
m 3 ), and mainly positive values of 
sea-surface height, all of which sug¬ 
gested that dolphinfish spp. associ¬ 
ate with oceanographic features, 
such as anticyclonic eddies. There 
was a seasonal SE—NW-NE move¬ 
ment of high incidental catch across 
survey quadrants (l°xl°), move¬ 
ment that is closely related to the 
latitudinal displacement of the 25°C 
isotherm. 
Manuscript submitted 25 January 2017. 
Manuscript accepted 18 October 2017. 
Fish. Bull. 116:9-20 (2018). 
Online publication date: 7 November 2017. 
doi: 10.7755/FB. 116.1.2 
The views and opinions expressed or 
implied in this article are those of the 
author (or authors) and do not necessarily 
reflect the position of the National 
Marine Fisheries Service, NOAA. 
Emigdio Marin-Enriquez 
Arturo Muhlia-Melo (contact author) 
Fish commonly known as dolphin¬ 
fish are members of the family Co- 
ryphaenidae, which represents only 
one genus, Coryphaena, but 2 spe¬ 
cies, the common dolphinfish ( Cory¬ 
phaena hippurus) and the pompano 
dolphinfish (C. equiselis ) (Gibbs and 
Collette, 1959). 
Dolphinfish, or both species of 
dolphinfish (hereafter “dolphinfish”), 
inhabit the tropical and subtropi¬ 
cal waters of the world and can be 
found from 40°N to 40°S (Palko et 
al., 1982); they are fast-swimming, 
fast-growing voracious predators, ca¬ 
pable of making considerable migra¬ 
tions (Alejo-Plata et al., 2011) and 
of passing through different fishery 
management zones within short pe¬ 
riods of time (Farrell, 2009). Their 
distribution is limited by the 20°C 
isotherm (Palko et al., 1982), and 
seasonal and interannual changes 
in sea-surface temperature (SST) 
influence their local catch rate and 
abundance (Kraul, 1999; Norton, 
1999; Zuniga-Flores et ah, 2008); ad¬ 
ditionally, their distribution seems 
to be influenced by prey availability 
and metabolic needs for sustaining 
their rapid growth (Schwenke, 2004). 
These fish are opportunistic preda¬ 
tors and feed on a wide spectrum of 
prey, which includes several species 
of bony fish, cephalopods, and crusta¬ 
ceans (Aguilar-Palomino et ah, 1998; 
Massutf et al., 1998; Oxenford, 1999; 
Sakamoto and Kojima; 1999; Tripp- 
Valdez et al., 2010). 
Despite dolphinfish having been 
reserved for the recreational fishery 
within 92.6 km (50 nmi) from the 
coastline since 1986 (Sosa-Nishizaki, 
1998), they are the primary species 
caught by the artisanal shark fleet 
in some states of central and south 
Mexico, where dolphinfish alone can 
contribute to more than 50% of the 
total catch (Madrid and Beltran, 
2001; Damian-Guillen et al., 2010; 
Miranda-Carrillo et al., 2010). Dol¬ 
phinfish are also caught incidentally 
by the tuna purse-seine (Arenas et 
al., 1999) and longline fleets (Santa- 
na-Hernandez, 2001), in both coastal 
and offshore waters off Mexico. 
Because of its circumtropical and 
subtropical distribution and its bio¬ 
logical characteristics (fast growth, 
early maturity, and high fecundity), 
high catch rates of dolphinfish are re¬ 
ported all over the world, where they 
are targeted by commercial and rec¬ 
reational fisheries (Martinez-Rincon 
