National Marine 
Fisheries Service 
NOAA 
Fishery Bulletin 
@ established in 1881 << 
Spencer F. Baird 
First U.S. Commissioner 
of Fisheries and founder 
of Fishery Bulletin 
Abstract—The role of deepwater cor- 
als and sponges in the life history of fish 
species is generally unknown for the 
larval stage. In 2017, we deployed an 
autonomous plankton pump into deep- 
water coral habitat (depths: >50 m) to 
examine which species were present and 
captured a single rockfish larva. Using 
genetic methods, we identified the larva 
as a northern rockfish (Sebastes poly- 
spinis). The unique capture of a free- 
swimming larva with a plankton pump 
in this study is the first in situ record 
of the use of deepwater coral habitat 
by rockfish larvae. Subsequent reex- 
amination of coral specimens captured 
in bottom-trawl surveys that had been 
conducted in the Gulf of Alaska yielded 
an additional 10 northern rockfish lar- 
vae and a single harlequin rockfish 
(S. variegatus) larva lodged in the pol- 
yps of 2 species of deepwater coral. The 
results of this study improve our know]- 
edge of the early life history of rockfish 
species, a taxonomic group that has 
limited lifetime dispersal indicated by a 
high degree of population structure. The 
capture and identification of the larva 
also indicate a potential mechanism 
for larval retention in the area of their 
extrusion and highlight the further 
importance of deepwater coral habitat 
as essential habitat for rockfish species. 
Manuscript submitted 25 August 2021. 
Manuscript accepted 18 February 2022. 
Fish. Bull. 120:74—78 (2022). 
Online publication date: 3 March 2022. 
doi: 10.7755/FB.120.1.7 
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. 
First observation of the use of coral habitat 
by larval northern rockfish (Sebastes polyspinis) 
in the western Gulf of Alaska 
Rachel E. Wilborn' 
Ingrid Spies? 
Pamela Goddard' 
Christopher N. Rooper (contact author)* 
James W. Orr? 
Email address for contact author: chris.rooper@dfo-mpo.gc.ca 
" Lynker Technologies LLC 
for Alaska Fisheries Science Center 
National Marine Fisheries Service, NOAA 
7600 Sand Point Way NE 
Seattle, Washington 98115 
2 Alaska Fisheries Science Center 
National Marine Fisheries Service, NOAA 
7600 Sand Point Way NE 
Seattle, Washington 98115 
Deepwater coral and sponge habitats 
have been reported to support a higher 
diversity and abundance of many 
marine fish and invertebrate species 
than other non-structured habitats 
(Buhl-Mortensen and Mortensen, 
2004; Watling et al., 2011). In the 
Northeast Pacific Ocean, rockfishes 
(Sebastes spp.) are linked to deepwa- 
ter (depths: >50 m) corals and sponges 
because of their preference for struc- 
tured habitats (Rooper et al., 2007). 
These studies were conducted almost 
exclusively on the juvenile and adult 
stages of the life history of rockfishes 
and other species, and the role of 
deep-sea corals and sponges in the 
larval stage of rockfishes is unknown. 
Understanding whether rockfish in 
early life stages utilize deep-sea coral 
and sponge habitats as settlement or 
nursery grounds is key to understand- 
ing their full life history and to con- 
serving essential habitat. 
Early juvenile stages of rockfishes 
have been found to recruit in higher 
3 Pacific Biological Station 
Fisheries and Oceans Canada 
3190 Hammond Bay Road 
Nanaimo, British Columbia V9T 6N7, 
Canada 
densities to structured habitats than 
in habitats without structure (Love 
et al., 1991; Rooper et al., 2007; Love 
et al., 2012), indicating that structured 
habitats are used as nurseries by rock- 
fish in early life history stages. It has 
been observed that, in shallow coral 
reef habitats (depths: <50 m), larval 
fish migrate vertically downward into 
corals to avoid currents, movements 
that can prevent larvae from being 
carried away and, therefore, can help 
them remain in coral habitat (Paris 
and Cowen, 2004). Redfish larvae 
(Sebastes spp.) have been captured in 
close association with sea pens (order 
Pennatulacea) by using bottom-trawl 
gear (Baillon et al., 2012). Sea pens 
may serve a similar purpose as corals 
in shallow-water habitats, by retain- 
ing larvae in nursery habitats with 
seafloor structure. These observations 
have led to the hypothesis that rock- 
fish in early life history stages recruit 
to and are retained in deep-sea coral 
habitats that are beneficial to their 
