NOAA Technical Memorandum NMFS-AFSC-75

U.S. DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

National Marine Fisheries Service

Alaska Fisheries Science Center

June 1997

by

B. L. Wing, C. W. Derrah, and V. M. O'Connell

Ichthyoplankton in the

Eastern Gulf of Alaska, May 1990
NOAA Technical Memorandum NMFS

The National Marine Fisheries Service’s Alaska Fisheries Science Center uses

the NOAA Technical Memorandum series to issue informal scientific and

technical publications when complete formal review and editorial processing

are not appropriate or feasible. Documents within this series reflect sound

professional work and may be referenced in the formal scientific and technical

literature.

The NMFS-AFSC Technical Memorandum series of the Alaska Fisheries

Science Center continues the NMFS-F/NWC series established in 1970 by the

Northwest Fisheries Center. The new NMFS-NWFSC series will be used by

the Northwest Fisheries Science Center.

This document should be cited as follows:

Wing, B. L., C. W. Derrah, and V. M. O’Connell. 1997.

Ichthyoplankton in the eastern Gulf of Alaska, May 1990. U.S. Dep.

Commer., NOAA Tech. Memo. NMFS-AFSC-75,42 p.

Reference in this document to trade names does not imply endorsement by

the National Marine Fisheries Service, NOAA.
June 1997

NOAA Technical Memorandum NMFS-AFSC-75

by

B. L. Wing, C. W. Derrah, and V. M. O'Connell

Ichthyoplankton in the

Eastern Gulf of Alaska, May 1990

Auke Bay Laboratory

Alaska Fisheries Science Center

11305 Glacier Highway

Juneau AK 99801-8626

 Resource Ecology and Fisheries Management Division

Alaska Fisheries Science Center

7600 Sand Point Way N.E., BIN C-15700

Seattle, WA 98115-0070

Commercial Fisheries Division

Alaska Department of Fish and Game

304 Lake Street, Room 103

Sitka AK 99835-7563

U.S. DEPARTMENT OF COMMERCE

William M. Daley, Secretary

National Oceanic and Atmospheric Administration

D. James Baker, Under Secretary and Administrator

National Marine Fisheries Service

Rolland A. Schmitten, Assistant Administrator for Fisheries

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111

ABSTRACT

Ichthyoplankton was collected by oblique bongo net tows at 67 stations in the

eastern Gulf of Alaska in May 1990. Stations ranged from nearshore to 230 km offshore.

Larvae of 20 families (53 genera, 88 species) and eggs of 4 families (12’ species) of fish

were identified. Rockfish (Sebastes spp.) were the most diverse and abundant group of

larvae. Rockfish larvae were caught at a11 stations and made up 56% (5,053) of the larvae

sampled. Highest abundances of rockfish larvae (>400/10 m2) were at stations beyond the

continental shelf. All rockfish larvae were in the preflexon stage, making identification at

the species level difficult. The most commonly occurring rockfish larvae were probably

Sebastes flaidus, based on pigment patterns. The relatively high offshore abundance of

larvae of inshore rockfish and other shallow-dwelling fishes supports the hypotheses of

offshore transport by anticyclonic circulation of the Sitka Eddy, or by freshwater or winddriven transport in the absence of the Sitka Eddy.

V

CONTENTS

ABSTRACT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iii

INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

MATERIALS AND METHODS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

RESULTS .................................................... 2

Abundances and Distribution .................................. 3

Scorpaenidae ........................................ 3

Ammodytidae ....................................... 3

Myctophidae ........................................ 3

Bathylagidae ......................................... 4

Gadidae ........................................... 4

Anoplopomatidae ..................................... 4

Cyclopteridae ........................................ 4

Clupeidae .......................................... 5

Pleuronectidae ....................................... 5

Cottidae ........................................... 5

Other Families and Species .............................. 5

Eggs .............................................. 6

DISCUSSION ................................................. 6

Species Assemblages ........................................ 6

Distribution Influences ...................................... 7

ACKNOWLEDGMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

CITATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ... . ... .9

TABLES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

FIGURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
vi

LIST OF TABLES

Table l.-Number, rank, and frequency of fish larvae collected in bongo net tows

in the eastern Gulf of Alaska, May 1990. . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Table 2.-Number, rank, and frequency of rockfish larvae (Sebastes spp.) collected

in bongo net tows in the eastern Gulf of Alaska, May 1990. . . . . . . . . . . . . . 17

Table 3.-Number, rank, and frequency of fish eggs collected in bongo net tows in

the eastern Gulf of Alaska, May 1990. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

LIST OF FIGURES

Figure l.-Stations occupied for bongo net tows in the eastern Gulf of Alaska,

May 1990 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Figure 2.-Distribution of Sebastes spp. larvae in the eastern Gulf of Alaska, May

1990. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Figure 3.-Distribution of Ammodytes hexapterus larvae in the eastern Gulf of

Alaska, May 1990. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Figure 4.-Distribution of Stenobrachius Zeucopsarus in the eastern Gulf of Alaska,

May 1990 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Figure 5.-Distribution of Protomyctophum thompsoni larvae in the eastern Gulf of

Alaska, May 1990. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Figure 6.-Distribution of Diaphus theta larvae and juveniles in the eastern Gulf of

Alaska, May 1990. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Figure 7.-Distribution of Leuroglossus schmidti larvae in the eastern Gulf of

Alaska, May 1990. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Figure 8.-Distribution of Bathylagus pacificus in the eastern Gulf of Alaska, May

1990. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Figure 9.-Distribution of Theragra chakogramma larvae in the eastern Gulf of

Alaska, May 1990. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Figure 1 O.-Distribution of Microgadus proximus and Gadus macrocephalus larvae

in the eastern Gulf of Alaska, May 1990. . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Figure 11 .-Distribution of Anoplopoma fimbria larvae in the eastern Gulf of

Alaska, May 1990. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Figure 12.-Distribution of Liparis spp. larvae in the eastern Gulf of Alaska, May

1990. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Figure 13.-Distribution of Clupea pallasi in the eastern Gulf of Alaska, May

1990. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
vii

Figure 14.-Distribution of Atheresthes stomias larvae in the eastern Gulf of

Alaska, May 1990. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

Figure 15.-Distribution of Hippoglossoides elassodon larvae in the eastern Gulf of

Alaska, May 1990. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Figure 16.-Distribution of Microstomus pacificus larvae in the eastern Gulf of

Alaska, May 1990. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

Figure 17.-Distribution of Errex zachirus larvae in the eastern Gulf of Alaska,

May 1990 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ....... 37

Figure 18.-Distribution of sculpin (Cottidae) larvae in the eastern Gulf of Alaska,

May 1990 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ................ 38

Figure 19.-Distribution of Microstomus pacficus eggs in the eastern Gulf of

Alaska, May 1990. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

Figure 20.-Distribution of Errex zachirus eggs in the eastern Gulf of Alaska, May

1990. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

Figure 21 .-Distribution of five species of flatfish eggs in the eastern Gulf of

Alaska, May 1990. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

Figure 22.-Distribution of Icosteus aenigmaticus eggs in the eastern Gulf of

Alaska, May 1990. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
INTRODUCTION

Ichthyoplankton surveys in the eastern North Pacific Ocean have been conducted

primarily off the coasts of Baja California, California, Oregon, and Washington and to a

lesser extent British Columbia (Fiedler 1986, Dunn 1986, Doyle et al. 1993). In Alaska

waters, most ichthyoplankton surveys have been in the eastern Bering Sea and western

Gulf of Alaska, especially in Shelikof Strait and the Shumagin Islands area (Dunn 1986,

Reed et al. 1988, Napp et al. 1996). Notably lacking are published data from the eastern

Gulf of Alaska, including Prince William Sound and offshore waters of southeastern

Alaska. Limited studies from southeastern Alaska include a survey of ichthyoplankton in

the northern inside waters of southeastern Alaska (Mattson and Wing 1978), and studies in

Auke Bay near Juneau associated with the spring bloom (Haldorson et al. 1990), Pacific

herring (Clupea pallasi) (Jones 1978, McGurk 1989), and walleye pollock (Theragra

chalcogramma) (Salveson 1984, Krieger 1985).

Environmental conditions, in particular oceanographic currents, may influence the

distribution, growth, and survival of marine fish larvae and juveniles (Reed et al. 1988,

Schumacher and Kendall 1995, Hermann et al. 1996). In May 1990, we conducted an

oceanographic survey of the eastern Gulf of Alaska to determine the presence or absence

of the Sitka Eddy, which is believed to have significant influence on pelagic and bottom

fisheries of Alaska and British’ Columbia (Tabata 1982, Mysak 1985, Hamilton and Mysak

1986, Karinen and Wing 1987). This paper reports ichthyoplankton catches from bongo

net sampling during May 1990 off the coast of southeastern Alaska.

MATERIALS AND METHODS

Ichthyoplankton samples were taken by the NOAA ship Townsend Cromwell,

7-22 May 1990, at 67 of 95 oceanographic stations occupied along 8 east-west transects

from Dixon Entrance (lat. 54o30’N) to Cross Sound, Alaska (lat. 58°00’N) (Fig. 1).

Transects extended from the coast to long. 136o00’W in the south and to long. 14OoOO’W

in the north. Stations were spaced approximately 14.8 km (8 nautical miles [nmi]) apart

on the continental shelf on east-west transects. Seaward of the continental shelf, stations

were approximately 3 1.5 km (17 nmi) apart. Transects were 55.6 km (30 nmi) apart north

to south.

Sampling began at Dixon Entrance (Station 94) on 7 May but was terminated on

8 May due to equipment loss. Sampling was restarted on 10 May off Cross Sound

(Station l), and stations were occupied from north to south through 22 May 1990.

Sampling at the 9 stations occupied on 7-8 May was repeated on 21-22 May, and daynight comparison tows were made at Station 44 on 22 May.

Ichthyoplankton were collected by oblique tows with a 60-cm diameter bongo net

array fitted with two 505-pm-mesh nets and cod ends. A General Oceanics model 2030

flowmeter was installed in the mouth of each net, and a Benthos model 1170-E-l 000

bathykymograph (BKG) was suspended 0.5 m below the nets. The array was set at

45-50 m per minute and retrieved at 30-35 m per minute. Wire angles were monitored

visually and electronically with an inclinometer and were used to judge depth during a
2

tow. Vessel speed was varied from 2.8 to 3.7 km/h (1.5 to 2.0 knots) to maintain a 45o

wire angle and uniform towing profile. Maximum sampling depth was targeted for 300 m,

but varied according to bottom depth while over shallower depths, wire angle, currents,

and weather conditions. The departure from the standard Marine Resources Monitoring,

Assessment, and Prediction Program (MARMAP) depth of 200 m (Jossi et al. 1975)

assured sampling through the permanent pycnocline and increased the probability of

capturing eggs and larvae of fish spawning along the continental slope.

Following net retrieval, the catches were gently rinsed from the cod ends into

sample bottles and preserved in 5% formaldehyde-seawater solution buffered with sodium

tetraborate. Preserved samples were sorted in the laboratory under dissecting microscopes

at magnifications of 7X-40X. After being sorted, eggs were stored in 5% buffered

formaldehyde and larvae in 40% isopropyl alcohol at Auke Bay Laboratory. Eggs and

larvae were identified to the lowest taxonomic level possible using current literature

(Kendall and Lenarz 1987, Matarese et al. 1989) and comparative specimens. Counts of

fish eggs and larvae were converted to numbers per 10 m2 of surface area based on

flowmeter readings, depth of tow, and duration of tow (Smith and Richardson 1977).

Catches from the paired nets were combined for counts at each station.

Rockfish (Sebastes spp.) larvae are difficult to identify to species, especially the

preflexon larvae, because they are a specious group with many sibling species and the

characteristics used for identification vary with size and between similar-sized individuals

of the same species (Kendall and Lenarz 1987, Kendall 1991, Seeb and Kendall 1991,

Moreno 1993). For this reason, subsamples of larvae (4-13 mm standard length [SL])

from 10 stations were sorted for Sebastes spp. larvae before being fixed, and these larvae

were frozen on plastic petri plates for electrophoretic allozyme analysis (Seeb and Kendall

1991, Seeb 1993). Forty larvae were analyzed for allozyme activity and compared to

adult tissue samples from 10 species of Sebastes (Seeb 1993).

RESULTS

A total of 8,972 larval and juvenile fish were sorted from the samples, of which

8,914 were identified to species or genus, 26 identified to family, and 32 not identified

(Table 1). Four distinct taxa of fish larvae could not be placed in known families.

Overall, twenty families represented by more than 90 species in 53 genera were present in

the samples. The most diverse group was the rockfish genus Sebastes (family

Scorpaenidae) with 27 types (putative species) separated on the basis of morphology, size,

and pigment patterns of preflexon larvae (Table 2). The families Pleuronectidae and

Cottidae were represented by 14 and 12 species, respectively. Other families were

represented by l-4 species each. Planktonic fish eggs of eight species of Pleuronectidae

and one species each of Bathylagidae, Gadidae, Icosteidae, Macrouridae, and one

unidentified family were sampled (Table 3).
Abundances and Distribution

Twenty-two of the 67 ichthyoplankton stations were occupied after sunset and

before sunrise. Day-night differences in abundance were not statistically significant (t0.95(63)

< |2.00|, P > 0.05) for 14 taxa collected at both day and night stations.

Scorpaenidae

Rockfish larvae occurred at all stations and comprised 56% of the fish larvae

identified (Fig. 2, Table 1). All rockfish larvae collected were in the preflexon stage of

development. The formaldehyde-preserved specimens of Sebastes were separated into 27

species “types” based primarily on pigmentation patterns. The most abundant type closely

resembled yellowtail rockfish (S. fravidus) as described by and illustrated by Matarese

et al. (1989). This species accounted for 30% of the rockfish and 17% of all fish larvae,

and was found at all stations (Table 2). The second most numerous rockfish larvae (11%

of the rockfish, and 6.3% of all fish larvae) most closely resembled harlequin rockfish

(S. variegatus) larvae. The third most abundant rockfish larvae (10% of the rockfish, and

5.7% of all fish larvae) most closely resembled sharpchin rockfish (S. zacentrus).

Forty Sebastes larvae from two stations (44 and 85) were analyzed for allozyme

activity and compared to adult tissues of 10 species of Sebastes (Seeb 1993). Although

positive identification was not possible for most of these larvae, nine specimens were

identified as probable Pacific ocean perch (S. alutus) and one specimen as rougheye

rockfish (S. aleutianus). Other probable species included shortraker rockfish (S. borealis),

dusky rockfrsh (S. ciliatus), canary rockfish (S. pinniger), and redstripe rockfish

(S. proriger). The allozyme comparisons also excluded four species from consideration:

redbanded rockfish (S. babcocki), quillback rockfish (S. maliger), tiger rockfish

(S. nigrocinctus), and yelloweye rockfish (S. ruberrimus) (Table 3 in Seeb 1993).

Ammodytidae

Pacific sand lance (Ammodytes hexapterus) nearly tied putative yellowtail rockfish

at 16% of the total fish larvae, but they were abundant at only two stations (Fig. 3). The

large catches of Pacific sand lance juveniles at these two night stations accounted for 95%

of the Pacific sand lance taken. The remaining 5% of the Pacific sand lance larvae were

from 15 day stations and 9 night stations.

Myctophidae

Lanternfish larvae, juveniles, and adults were represented by six species. The

northern lampfish (Stenobrachius leucopsarus), the most abundant and widely distributed

lanternfish, ranked third in abundance of all fish larvae and was found at 61 stations
4

(Fig. 4). The bigeye lampfish (Protomyctophum thompsoni), found at 40 stations, ranked

eighth in abundance of total larvae (Fig. 5). California headlight&h (Diaphus theta) was

taken at five day and five night stations (Fig. 6). Blue lanternfish (Tarletonbeania

crenularis) was taken at only two stations. Juvenile pinpoint lampfish (Lampanyctus

regazis) and broadfin lampfish (L. ritteri) were taken once each.

Bathylagidae

Larvae of three species of deepsea smelts were found in the bongo net samples.

Larvae of northern smoothtongue (Leuroglossus schmidti), the most abundant bathylagid,

were identified from 16 stations and ranked 10th in abundance (Fig. 7). Larvae of the

Pacific blacksmelt (Bathylagus pacificus) were identified from 29 stations, and ranked 11th

in abundance (Fig. 8). Single robust blacksmelt (Bathylagus milleri) larvae were found at

three stations.

Gadidae

Gadid larvae were sparsely distributed among the samples. Walleye pollock

(Theragra chalcogramma) was the most numerous gadid, ranking sixth in abundance, but

was found at only 22 stations (Fig. 9). Pacific tomcod (Microgadus proximus) and Pacific

cod (Gadus macrocephalus) occurred at only four and five stations, respectively (Fig. 10).

Anoplopomatidae

Sablefish (Anoplopoma fimbria) larvae were found at 39 stations, ranking fifth in

overall abundance. Most sablefish larvae were distributed offshore at stations beyond the

continental slope (Fig. 11). Mean abundance of sablefish larvae was also highest in

neuston tows at stations seaward of the continental slope (Wing 1997).

Cyclopteridae

Snailfishes were represented by the genus Liparis. At least two species were

present. Most specimens were a form with inflated integument surrounding the head and

forward portion of the body (bubblemorph), more closely resembling slipskin snailfish

(Liparis ficensis) larvae described by Marliave and Peden (1989) than by Ambrose (1996)

in intensity of pigmentation. Liparid larvae were found at both near-shore and offshore

stations (Fig. 12).
5

Clupeidae

Pacific herring (Clupea pallasi) ranked ninth in abundance. Pacific herring spawn

intertidally and subtidally in the sounds and bays along the southeastern Alaska coast

adjacent to our survey area (Skud 1959). The occurrence of herring larvae at six offshore

stations (Fig. 13) may be the result of offshore transport of surface waters in the spring of

1990.

Pleuronectidae

Flatfish larvae were represented by 14 species. Arrowtooth flounder (Atheresthes

stomias) was the most abundant flatfish and ranked fourth in overall abundance (Fig. 14).

Dover sole (Microstomus pacificus) and flathead sole (Hippoglossoides elassodon) ranked

12th and 13th, respectively. Flathead sole larvae were found at 8 stations (Fig. 15),

whereas Dover sole occurred at 18 stations (Fig. 16). Rex sole (Errex zachirus) occurred

at 14 stations and ranked 16th in abundance (Fig. 17). The geographic distributions of

these flatfish larvae broadly overlap and show extensive offshore distribution.

Cottidae

Fourteen species of cottid larvae were identified, reflecting the high diversity of

sculpins in the northeastern Pacific Ocean. Most of the cottid larvae collected were

species believed to spawn and reside as adults intertidally or in relatively shallow

nearshore waters. None of the cottids was abundant (Table 1). The various cottids were

represented by single specimens at 19 of 20 stations. Brown Irish lord (Hemilepidotus

spinosus; eight specimens) were collected at three stations (Fig. 18). In contrast, red Irish

lord (H. hemilepidotus) and yellow Irish lord (H. jordani), occurring as single individuals

at four stations in the bongo net samples, were frequently encountered in neuston samples

during the same cruise (Wing and Kamikawa 1995).

Other Families and Species

Forty-two species were present at six or fewer stations, and 23 species were represented by single individuals (Table 1). Many of these species, especially the cottids, are

believed to spawn intertidally or in relatively shallow nearshore waters. Others represent

pelagic midwater species or benthic species residing below the shelf break, whose larvae

may rarely occur above 300 m depth.
6

Eggs

Fish eggs were not abundant in our samples and showed little diversity. Of the 12

species of eggs identified, only 3 species were found in more than 10% of the samples or

at more than six stations (Table 3). The most abundant and frequently occurring of these

eggs were Dover sole eggs, present at 52 stations (Fig. 19). Rex sole eggs, present at 22

stations (Fig. 20), did not have a discernible pattern of distribution or abundance. Larvae

of Dover sole and rex sole were present at few stations where their eggs were found.

Other flatfish eggs were rare (Table 3) and widely scattered (Fig. 21). Ragfish (Icosteus

aenigmaticus) eggs were present at 48 stations (Fig. 22), with highest concentrations in the

southern offshore portions of the survey area. We found no planktonic ragfish larvae in

our samples, although advanced embryos were in the eggs at several stations.

DISCUSSION

Species Assemblages

The ichthyoplankton of the eastern Gulf of Alaska can be grouped into three

spawning assemblages: pelagic midwater spawners, slope spawners, and shelf spawners.

Pelagic midwater species were represented in our samples by lanternfishes, deepsea smelts,

and viperfish. Although these species spawn at varying times and depths, their eggs and

larvae are widely distributed both within the water column and throughout the area. The

northern lampfish and northern smoothtongue are characteristic of this group and are

among the most frequently occurring and abundant species in our survey area. Both

species are also common in ichthyoplankton samples from the inside waters of

southeastern Alaska in April through November (Mattson and Wing 1978).

Benthic slope species with pelagic eggs and larvae were represented in our samples

by several flatfishes, primarily the Dover sole, rex sole, arrowtooth flounder, and Pacific

halibut (Hippoglossus stenolepis). Sablefish and some of the rockfishes that either reside

on the slope or move to the slope for parturition (larval release) (O’Connell 1987) may be

placed in this group.

Shelf-spawning species were represented in our samples by Pacific herring,

sculpins, snailfish, and flatfishes. This assemblage includes species with demersal eggs

and species with planktonic eggs, although the larvae of some nearshore and intertidal

spawning fishes are seldom found offshore. The resident rockfishes of the nearshore areas

may be considered as a subgroup of the shelf species.

The neustonic larvae form a distinctive behavioral group that has species from the

slope- and shelf-spawning assemblages. The neustonic fish larvae of the eastern Gulf of

Alaska are dominated by the sablefish, greenlings, and cottids (Wing and Kamikawa

1995). Sablefish were the most abundant larvae in neuston samples from this cruise

(Wing and Kamikawa 1995, Wing 1997). Low abundance and low frequency in oblique
7

or vertical net tows and moderate to high abundance in neuston tows are characteristic of

this group (Wing 1997).

Distribution Influences

Eggs and larvae of fish may rise or sink through the water column as they develop.

Density structure and associated temperature, salinity, and light gradients influence the

vertical distribution of fish eggs and larvae, and the depth distribution varies with

developmental stage (Kendall and Kim 1989, Olla and Davis 1990). If there is significant

vertical variation in current direction and velocity, late developmental stages are expected

to have wider and more varied spatial distribution than early stages. Although age and

size determinations were not attempted in our analyses, the wide oceanic distribution of

some shelf and slope species in our samples may be the result of older stages being carried

offshore from spawning areas as they rise through the water column.

Preliminary analysis of the physical oceanographic data indicated that the Sitka

Eddy was not present in the survey area during May 1990 (Musgrave and Wing 1991,

Wing and Kamikawa 1995), although a very complex current system with four or more

small eddies was present in the upper 250 m of the water column.’ The strongest current

velocities were observed along the 56o30’N transect, where five alternating north and

south flows were observed in the upper 50 m of the water column. The northward

geostrophic current exceeded 20 cm set-1 at Station 48, and the southward geostrophic

flow was over 17 cm set-1 at Station 50. Three to six alternating north and south flows

were observed on the other transects. This complex of eddies and currents may be the

mechanism for transport of fish larvae and eggs offshore from spawning areas on the

continental shelf and continental slope. It may also be the mechanism for returning the

fish larvae to inshore nursery areas.

The peak spawning, hatching, and parturition periods of most fish in Alaska are

poorly known. Abundant species during this survey may indicate proximity to peak

spawning periods, but sampling before and after May is needed to confirm peak spawning.

Because planktonic larvae are expected to be carried away from spawning sites by currents

and mixing processes, they may be more widely distributed than planktonic eggs. An

indication that we sampled before or during a peak spawning period is the wider

distribution of Dover sole and rex sole eggs than of their larvae.

In addition to the environmental factors influencing survival of fish larvae and fish

eggs, behavioral traits contribute to the abundance of several species in our samples.

Some nearshore and intertidal species (e.g., Pacific sandfish Trichodon trichodon) hatch at

an advanced stage and seek benthic habitats shortly after hatching (Marliave 1980, Bailey

et al. 1983), and thus never truly enter the ichthyoplankton community. Recently, a deepdwelling snailfish, Careproctus sp., also was found to hatch as advanced larvae with

1D. Musgrave, Institute of Marine Sciences, University of Alaska Fairbanks, Fairbanks, AK 997751080; pers.

commun., June 1995.
8

bottom-seeking behavior (Love and Shirley 1993). Various snailfishes, sculpins, eelpouts,

pricklebacks, etc. which appear common in benthic habitats, but rare in ichthyoplankton,

may have similar behavior (Marliave 1986).

In contrast to the bottom-seeking species are the neustonic species, which although

rare in standard oblique tows, are occasionally numerous and dominant in neuston

samples. Greenlings, Irish lords, sablefish, and perhaps some salmonids appear adapted to

dwell near the surface, where they are susceptible to neuston nets but only infrequently

taken in oblique tows (Wing and Kamikawa 1995, Wing 1997). This limited distribution

within a small portion of the water column in combination with schooling behavior at an

early stage may result in under-representation of those species in ichthyoplankton surveys.

ACKNOWLEDGMENTS

We thank the officers and crew of the NOAA ship Townsend Cromwell for their

assistance and hospitality during the cruise. Blaine Ebberts and Daniel Kamikawa (Auke

Bay Lab) assisted in collections of samples, and David Gordon and Peter Cleary (Alaska

Department of Fish and Game, Sitka) assisted in sorting and identification of the fish eggs

and larvae. Morgan Busby (NMFS, AFSC, PACE, Seattle, WA) provided identification

of Agonid larvae and critical review of the manuscript. We thank Lisa Seeb (Alaska

Department of Fish and Game, Anchorage) for the allozyme analysis of rockfish larvae.
9

CITATIONS

Ambrose, D. A. 1996. Cyclopteridae: Snailfishes and lumpsuckers. In H. G. Moser

(editor), The early stages of fishes in the California Current region, p. 860-871.

Calif. Coop. Oceanic Fish. Invest. Atlas 33.

Bailey, J. E., B. L. Wing, and J. H. Landingham. 1983. Juvenile Pacific sandfish,

Trichodon, associated with pink salmon, Oncorhynchus gorbuscha, fry in the

nearshore area, southeastern Alaska. Copeia 1983:549-55 1.

Doyle, M. J., W. W. Morse, and A. W. Kendall, Jr. 1993. A comparison of larval fish

assemblages in the temperate zone of the northeast Pacific and northwest Atlantic

Oceans. Bull. Mar. Sci. 53:588-644.

Dunn, J. R. 1986. A catalog of Northwest and Alaska Fisheries Center ichthyoplankton

cruises 1965-1985. U.S. Dep. Commer., NOAA, Natl. Mar. Fish, Serv., NWAFC

Processed Report 86-08, 76 p. + 85 fig.

Fiedler, P C. 1986. Offshore entrainment of anchovy spawning habitat, eggs, and larvae

by a displaced eddy in 1985. Calif. Coop. Oceanic Fish. Invest. Rep. 27: 144-152.

Haldorson, L., M. Pritchett, D. Sterritt, and J. Watts. 1990. Interannual variability in the

recruitment potential of larval fishes in Auke Bay, Alaska. In D. A. Zieman and

K. W. Fulton-Bennett (editors), APPRISE-Interannual variability and fisheries

recruitment, p. 319-356. The Oceanic Institute, Honolulu, HI.

Hamilton, K., and L. A. Mysak. 1986. Possible effects of the Sitka Eddy on sockeye

(Oncorhynchus nerka) and pink salmon (Oncorhynchus gorbuscha) migration off

southeast Alaska. Can. J. Fish. Aquat. Sci. 43:498-504.

Hermann, A. J., W. C. Rugen, P. J. Stabeno, and N. A. Bond. 1996. Physical transport

of young pollock larvae (Theragra chalcogramma) near Shelikof Strait as inferred

from a hydrodynamic model. Fish. Oceanogr. 5(Suppl.1):58-70.

Jones, J. D. 1978. Growth of larval Pacific herring in Auke Bay, Alaska in 1975 and

1976. M.S. thesis, Univ. Alaska, Juneau, 23 p.

Jossi, J. W., R. R. Marak, and H. Petersen, Jr. 1975. MARMAP survey I manual: At-sea

data collection and laboratory procedures. NOAA, Natl. Mar. Fish. Serv.,

MARMAP Program Office, Washington, D.C. 20235. (unpublished).

Karinen, J. F., and B. L. Wing. 1987. Age composition and recruitment trends of Pacific

ocean perch off southeastern Alaska in 1984 and 1986. In R. L. Major (editor),

Condition of groundfish resources of the Gulf of Alaska region as assessed in 1986,

p. 139-148. U.S. Dep. Commer., NOAA Tech. Memo. NMFS F/NWC-119.

Kendall, A. W., Jr. 1991. Systematics and identification of larvae and juveniles of the

genus Sebastes. Environ. Biol. Fishes 30: 173-l 90.

Kendall, A. W., Jr., and S. Kim. 1989. Buoyancy of walleye pollock (Theragra

chalcogramma) eggs in relation to water properties and movement in Shelikof

Strait, Gulf of Alaska. Can. Spec. Publ. Fish. Aquat. Sci. 108: 169-180.
10

Kendall, A. W., Jr., and W. H. Lenarz. 1987. Status of early life history studies of

northeast Pacific rockfishes. In Proceedings of the International Rockfish

Symposium, p. 99-128. Univ. Alaska Sea Grant Rep. 87-2, Fairbanks.

Krieger, K. J. 1985. Food habits and distribution of first-year walleye pollock, Theragra

chalcogramma (Pallas), in Auke Bay, southeastern Alaska. M.S. thesis, Univ.

Alaska, Juneau, 57 p.

Love, D. C., and T. C. Shirley. 1993. Parasitism of the golden king crab, Lithodes

aequispinus Benedict, 1895 (Decapoda, Anomura, Lithodidae), by a liparid fish.

Crustaceana 65:97-104.

Marliave, J. B. 1980. Spawn and larvae of the Pacific sandfish, Trichodon trichodon.

Fish. Bull., U.S. 78:959-964.

Marliave, J. B. 1986. Lack of planktonic dispersal of rocky intertidal fish larvae. Trans.

Amer. Fish. Soc. 115:149-154.

Marliave, J. B., and A. E. Peden. 1989. Larvae of Liparis fucensis and Liparis callyodon:

Is the “cottoid bubblemorph” phylogenetically significant? Fish. Bull., U.S. 87:

735-743.

Matarese, A. C., A. W. Kendall, Jr., D. M. Blood, and B. M. Vinter. 1989. Laboratory

guide to early life history stages of northeast Pacific fishes. U.S. Dep. Commer.,

NOAA Tech. Rep. NMFS 80, 652 p.

Mattson, C. R., and B. L. Wing. 1978. Ichthyoplankton composition and plankton

volumes from inland coastal waters of southeastern Alaska, April-November 1972.

U.S. Dep. Commer., NOAA Tech. Rep. NMFS SSRF-723, 11 p.

McGurk, M. D. 1989. Early life history of Pacific herring in Auke Bay, Alaska:

Relationships of growth and survival to environmental conditions. In Outer

Continental Shelf Environmental Assessment Program, Final reports of Principal

Investigators 63:279-421 RU 695.

Moreno, G. 1993. Description of early larvae of four northern California species of

rockfishes (Scorpaenidae: Sebastes) from rearing studies. U.S. Dep. Commer.,

NOAA Tech. Rep. NMFS 116, 18 p.

Musgrave, D. L., and B. L. Wing. 1991. Circulation and water-mass characteristics off

Southeast Alaska. EOS, Trans. Am. Geophys. Union, October 29, 1991, Suppl.

Am. Geophys. Union 1991 Fall Meeting Program and Abstracts, December 9-13,

1991. (Abstract OSlC-10).

Mysak, L. A. 1985. On the interannual variability of eddies in the northeast Pacific

Ocean. In W. S. Wooster and D. L. Fluharty (editors), El Nino North: Nino

effects in the eastern subarctic Pacific Ocean, p. 97-106. Washington Sea Grant

Program, Univ. Washington, Seattle, W-85-3.

Napp, J. M., L. S. Incze, F! B. Ortner, D. L. W. Siefert, and L. Britt. 1996. The

plankton of Shelikof Strait, Alaska: standing stock, production, mesoscale

variability and their relevance to larval fish survival. Fish. Oceanogr. 5(Supp1. 1):

19-38.
11

O’Connell, V. M. 1987. Reproductive seasons for some Sebastes species in southeastern

Alaska. Informational Leaflet 263, Alaska Dep. Fish and Game, Div. Commer.

Fish., Sitka, 99835, 21 p.

Olla, B. L., and M. W. Davis. 1990. Effects of physical factors on the vertical

distribution of larval walleye pollock Theragra chalcogramma under controlled

laboratory conditions. Mar. Ecol. Prog. Ser. 63:105-112.

Reed, R. K., J. D. Schumacher, and A. W. Kendall, Jr. 1988. NOAA’s Fisheries

Oceanography Coordinated Investigations in the western Gulf of Alaska. EOS,

Trans. Am. Geophys. Union 69:890-894.

Salveson, S. J. 1984. Growth and distribution of first-year walleye pollock, Theragra

chalcogramma, in north Stephens Passage, southeastern Alaska. M.S. thesis, Univ.

Alaska, Juneau, 59 p.

Schumacher, J., and A. W. Kendall, Jr. 1995. An example of fisheries oceanography:

Walleye pollock in Alaskan waters. Rev. Geophys. (Suppl.): 1153-1163

Seeb, L. W. 1993. Biochemical identification of larval rockfishes of the genus Sebastes.

Final Report for Contract #43ABNF001082. Resour. Assessment and Conserv.

Eng. Div., Alaska Fish. Sci. Cent., Natl. Mar. Fish. Serv., Seattle, WA.

Seeb, L. W., and A. W. Kendall, Jr. 1991. Allozyme polymorphisms permit the

identification of larval and juvenile rockfishes of the genus Sebastes. Environ.

Biol. Fishes 30:191-201.

Skud, B. E. 1959. Herring spawning surveys in southeastern Alaska. U.S. Fish Wildl.

Serv., Spec. Sci. Rep. Fish. 321, 16 p.

Smith, I? E., and S. L. Richardson. 1977. Standard techniques for pelagic fish egg and

larva surveys. FAO Fish. Tech. Pap. 175, 100 p.

Tabata, S. 1982. The anticyclonic, baroclinic eddy off Sitka, Alaska, in the northeast

Pacific Ocean. J. Phys. Oceanogr. 12: 1260-1282.

Wing, B. L. 1997. Distribution of sablefish larvae in the Eastern Gulf of Alaska:

Neuston net tows versus oblique bongo net tows. In M. Wilkins and M. Saunders

(editors), Proc. Int. Sablefish Symp., April 3-4, 1993, p. 13-25. U.S. Dep.

Commer., NOAA Tech. Rep. 130.

Wing, B. L., and D. J. Kamikawa. 1995. Distribution of neustonic sablefish larvae and

associated ichthyoplankton in the eastern Gulf of Alaska, May 1990. U.S. Dep.

Commer., NOAA Tech. Memo. NMFS-AFSC-53, 48 p.

TABLES

15

Table l.-Number, rank, and frequency of fish larvae collected in bongo net

tows in the eastern Gulf of Alaska, May 1990.
16

Table 1 .-Continued.
17

Table 2.-Number, rank, and frequency of rockfish larvae (Sebastes spp.)

collected in bongo net tows in the eastern Gulf of Alaska, May

1990.
18

Table 3.-Number, rank, and frequency of fish eggs collected in bongo net tows in

the eastern Gulf of Alaska, May 1990.
FIGURES



Figure 3.-Distribution of Ammodytes hexapterus larvae in the eastern Gulf of Alaska, May 1990. Abundance

expressed as number per 10 m2.



Figure 7.-Distribution of Leuroglossus schmidti larvae in the eastern Gulf of Alaska, May 1990.

as number per 10 m2.

Abundance expressed


Figure l0.-Distribution of Microgudus proximus and Gadus macrocephalus larvae in the eastern Gulf of Alaska, May

1990. Abundance expressed as number per 10 m2

. .


Figure 13.-Distribution of Clupea pallasi in the eastern Gulf of Alaska, May 1990. Abundance expressed as number

per 10 m2.
Figure 14.-Distribution of Atheresthes stomias larvae in the eastern Gulf of Alaska, May 1990. Abundance expressed

as number per 10 m2.
Figure 15.-Distribution of Hippoglossoides elassodon larvae in the eastern Gulf of Alaska, May 1990. Abundance

expressed as number per 10 m2

.
Figure 16.-Distribution of Microstomus pacificus larvae in the eastern Gulf of Alaska, May

expressed as number per 10 m2.

1 990. Abundance
Figure 17.-Distribution of Errex zachirus larvae in the eastern Gulf of Alaska, May 1990.

number per 10 m2.

Abundance expressed as
Figure 18.-Distribution of sculpin (Cottidae) larvae in the eastern Gulf of Alaska, May 1990.
Figure 19.-Distribution of Microstomus pacificus eggs in the eastern Gulf of Alaska, May 1990.

as number per 10 m2.

Abundance expressed


Figure 22.-Distribution of Icosteus aenigmaticus eggs in the eastern Gulf of Alaska, May 1990. Abundance expressed

as number per 10 m2.
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