180 
National Marine 
Fisheries Service 
NOAA 
Abstract-— The phenomenon of mul¬ 
tiple brooding, the production of more 
than one brood within a reproduc¬ 
tive season, is a poorly understood 
process in rockfishes (Sebastes spp.). 
Most species produce a single brood, 
and all stock assessment models for 
Sebastes species assume the repro¬ 
ductive output (fecundity) of a single 
annual brood. We evaluated how well 
this life history trait could be predicted 
by both oceanographic (mean latitude, 
ocean temperature, dissolved oxygen 
levels, and depth) and demographic 
(maximum length, maximum age, and 
natural mortality rate) factors for 24 
species of rockfish found on the conti¬ 
nental shelf along the West Coast of the 
United States. Our results indicate that 
multiple-brooding species are consider¬ 
ably more common in lower latitudes 
(32-36°N) or in warmer waters (>9°C 
at depth) and that the other environ¬ 
mental and demographic factors ana¬ 
lyzed were not empirically informative. 
This work provides a more comprehen¬ 
sive understanding of the reproduc¬ 
tive ecology of shelf rockfishes, could 
contribute to assessments of climate 
change vulnerability, and should even¬ 
tually lead to improvements in stock 
assessment models for economically 
and ecologically important rockfishes. 
Manuscript submitted 20 October 2018. 
Manuscript accepted 19 July 2019. 
Fish. Bull. 117:180-188 (2019). 
Online publication date: 31 July 2019. 
doi: 10.7755/FB. 117.3.5 
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. 
Fishery Bulletin 
rtr established in 1881 *<?. 
Spencer F. Baird 
First U S. Commissioner 
of Fisheries and founder 
of Fishery Bulletin 
An exploration of factors that relate to the 
occurrence of multiple brooding in rockfishes 
(Sebastes spp.) 
Anna M. Holder (contact author ) 1 
John C. Field 2 
Email address for contact author: aholder@csumb.edu 
1 California State University, Monterey Bay 
100 Campus Center 
Seaside, California 93955 
2 Fisheries Ecology Division 
Southwest Fisheries Science Center 
National Marine Fisheries Service, NOAA 
110 Shaffer Road 
Santa Cruz, California 95060 
Population dynamics models that 
inform management decisions require 
an understanding of the reproductive 
biology of the fish species that are being 
managed. Rockfishes (Sebastes spp.) 
of the northeast Pacific Ocean tend to 
be long-lived species (maximum ages 
of some species are between 50 and 
150 years) that can reach marketable 
size before maturity (Love et al., 1990). 
In addition to being long lived, slow 
growing, and late to mature, they have 
internal fertilization, are live-bearing, 
and usually develop a single brood 
annually (Love et al., 2002). Given 
these traits, which tend to be associ¬ 
ated with high standing stock biomass 
and low productivity, rockfishes tend 
to be among the stocks that are more 
vulnerable to fishing pressure and 
presumably to future climate change 
(Parker et al., 2000; Berkeley et al., 
2004; Cope et al., 2011). 
Despite the report of multiple brood¬ 
ing, the production of more than one 
brood within a reproductive season, 
in some rockfishes over 50 years ago 
(Moser, 1966), multiple brooding con¬ 
tinues to be poorly understood. Multi¬ 
ple brooding can be identified through 
macroscopic or histological examina¬ 
tion of the ovaries. In macroscopically 
examined ovaries, multiple broods can 
be identified when ovaries contain 
residual larvae or fertilized eggs (pri¬ 
mary brood) and developing oocytes 
(upcoming secondary brood) (Beyer 
et al., 2015; Lefebvre et al., 2018). Lefe- 
bvre et al. (2018) identified multiple 
brooding through histological exam¬ 
ination when ovaries contained post¬ 
ovulatory follicle complexes, residual 
larvae or eyed larvae (primary brood) 
and late-stage developing vitellogenic 
oocytes (upcoming secondary brood). 
Although many rockfish species have 
been identified as having the capac¬ 
ity to produce multiple broods (Moser, 
1967; Love et al., 1990; Beyer et al., 
2015; Lefebvre et al., 2018), the poten¬ 
tial for multiple brooding is unknown 
for a great many remaining species for 
which little data on their reproductive 
ecology exists. 
Traditional stock assessment met¬ 
rics, such as estimates of spawning 
stock biomass, depend on the repro¬ 
ductive strategies and annual fecun¬ 
dity of species. When data are not 
available, assumptions are made that 
