Temporal and Spatial Patterns in Abundance and ...

Estuaries

Vol. 14, No. 4, p. 465-480

December 1991

Temporal and Spatial Patterns in Abundance and Diversity of Fish Assemblages in Elkhorn Slough, California MARY M. YOKLAVICH’ GREGOR M. CAILLIET JAMES P. BARRY DAVID A. AMBROSE* BROOKE S. ANTRIM

Moss Landing Marine Laboratories P.O. Box 450 Moss Landing, Calqornia 95039 ABSTRACT: Assemblages of ichthyofauna of shallow inshore habitats along California’s central coast are described in terms of species composition, abundance, and life-style categories. A total of 22,334 fishes from 65 species and 27 families was collected with otter trawls at six sites in the main channel and tidal creeks of Elkhorn Slough, a tidal embayment and seasonal estuary, and two nearshore ocean stations in Monterey Bay during 44 months between August 1974 and June 1980. Greater than 90% of the catch comprised 10 species. The four dominant species,Cymatogaster aggregata, Leptocottus awnatus, Phanerodon fwcatus, and Embiotoca jacksoni, occurred during most or all seasons and were classified as residents or partial residents. Several abundant species were marine immigrants that seasonally use the slough as spawning and nursery grounds; this resulted in higher abundance and species richness during summer. Species collected during winter largely were slough residents. Species composition and richness varied with distance from the slough entrance. The ocean assemblage was most different, and its similarity to other stations decreased progressively with distance inland and into the tidal creeks. During our study, 5,074 fishes were collected by beach seine in Bennett Slough, a remote shallow marsh basin adjacent to the entrance of Elkhorn Slough. Species richness was relatively low and three euryhaline species accounted for X30% of the total catch. The species assemblage was most similar to those at the tidal creek and most shallow stations of Elkhorn Slough. Resident species numerically dominated assemblages in Bennett Slough and the most inland areas of Elkhorn Slough. The high relative abundance of marine-related fishes (classified as marine, marine immigrant, and partial resident) entering Elkhorn Slough early in life or as spawning adults indicates the importance of this habitat to nearshore fish assemblages.

Introduction

feed, as well as those completing their entire life cycle in the area, also can be considered to be dependent on estuarine systems. Because most species are not dependent entirely on estuaries and are found also in adjacent coastal environments, Lenanton and Potter (1987) suggested the term “estuarine opportunism.” Although difficult to evaluate because it requires seasonal sampling over several years in all major habitats of the estuary and adjacent marine area, the benefits derived by opportunistic members of the estuarine fish assemblage would be a measure of the interaction between estuarine and coastal marine environments (Darnell and Soniat 1979; Weinstein 198 1). Identifying this inshore-offshore relationship is important to maintaining all coastal resources. The functional relationship between estuaries and fish communities has been studied widely along the east coast of the United States, particularly in expansive tidal marshes (Shenker and Dean 1979;

Shallow bays and estuaries are recognized worldwide as productive habitats used by a variety of fishes for reproduction, feeding, and shelter (Odum and Heald 1975; Dando 1984; Day and YanezArancibia 1985, among others). These systems function as important nursery grounds for larval and juvenile stages of many marine fishes, potentially enhancing their early growth and survival (Allen 1982; Rosenberg 1982; Weinstein 1985). This nursery function often has been discussed in terms of the estuarine dependence of marine species. More broadly, estuarine dependence includes any species using estuaries as essential habitat during any life history stage (Blaber et al. 1989). Those species regularly entering estuaries to spawn or 1Current address: NOAA-Pacific Fisheries Environmental Group, P.O. Box 831, Monterey, California 93942. 2 Current address: NOAA-Southwest Fisheries Science Center, P.O. Box 27 1, La Jolla, California 92038-027 1. Q 1991 Estuarine Research

Federation

465

0160-8347/91/040485-i6$01.50/O

466

M. M. Yoklavich et al.

Weinstein 1979; Bozeman and Dean 1980). Although estuaries represent only 1 O-25% of the west coast, compared to SO-SO% of the Atlantic and Gulf of Mexico coasts (Day and Yanez-Arancibia 1985), they have been identified as important nursery and spawning areas for some commercially valuable marine fishes (Pearcy and Myers 1974; Krygier and Pearcy 1986; McGowan 1986; Gunderson et al. 1990). Bays and estuaries of California, in particular, are few in number and size; their total area is less than 15% that of Chesapeake Bay (Horn and Allen 1976). In addition, more than 75% of California’s coastal wetlands have been lost or degraded through pollution, diking, and filling (Onuf et al. 1978). Nonetheless, unique assemblages of fishes using those remaining coastal systems contribute to California’s nearshore marine resources (Allen 1982; Horn and Allen 1985). Fish assemblages of Elkhorn Slough, a primarily marine-influenced wetland habitat on the central California coast, have been studied since the mid1970s by faculty and graduate students of Moss Landing Marine Laboratories (California State University system). These investigations provide valuable information on life histories, abundance, and distribution of fishes throughout this system, including tidal creeks and adjacent Bennett Slough and marine coastal habitats (Ambrose 1976; Appiah 1977; Cailliet et al. 1977; Antrim 198 1; Barry and Cailliet 198 1; Yoklavich 1982; Barry 1983). Further interest has been stimulated by the recent designation of Elkhorn Slough as a member of the National Estuarine Research Reserve System and as the site of marsh restoration projects. Using data that were collected regularly during four years, the objectives of the present study were (1) to assess seasonal and spatial changes in species composition, abundance, and habitat associations of fish assemblages in Elkhorn Slough; and (2) to evaluate the interaction between fish assemblages in the slough and those in adjacent nearshore ocean habitat, especially in terms of “slough dependence or opportunism.” This study provides baseline information prerequisite to long-term monitoring of fish assemblages in Elkhorn Slough, their response to potential environmental changes (both naturally and human-induced), and their contribution to the nearshore fishery resources of Monterey Bay. Methods STUDY AREA Elkhorn Slough (36”48’N, 121”47’W) is low, tidal embayment and seasonal estuary head of the Monterey submarine canyon. It axial length of about 10 km and a relatively drainage basin of 585 km* (Fig. 1; Browning

a shalat the has an small 1972).

During our study, water depth of the main channel below mean lower low water (MLLW) ranged from about 5 m at the slough entrance to less than 2 m at the most inland station; average width of the main channel narrowed from 100 m at the entrance to 15 m furthest inland (Smith 1973; Broenkow 1977). The main channel is bordered by extensive mudflats (about 170 ha are exposed at MLLW) and is intersected by a network of tidal creeks that meander through adjacent salt marshes (about 583 ha comprised predominantly of pickleweed [Salicornia virgin&z]). Our study area included several sites along the main.channel of the slough, from the entrance to Hudson’s Landing (Fig. 1). In addition, we sampled Long Canyon, a tidal creek that is l-l .5 km long, 5-10 m wide and 2 m deep at its intersection with the main channel (about 4 km east of Moss Landing Harbor entrance), and receives freshwater runoff from the adjacent watershed. We also sampled Rubis Creek (Fig. I), which intersects the main channel across from Long Canyon Creek and is about the same width and depth but receives little freshwater runoff. Semidiurnal tides with a mean tidal range of 1.1 m result in well-mixed water in two environmentally distinct zones of the slough (Broenkow 1977). The area above the mean tidal prism, which is about 4.8 km inland, has a water residence time in excess of 300 d. Salinity in this region of the slough varied seasonally with evaporation, precipitation, and runoff, and ranged from 17%a in March to 37V&1 in June. Water temperature ranged from 12°C to 26°C. Water west of the tidal prism (about 75% of the mean high water volume) is exchanged daily and reflects nearshore ocean conditions, with cooler temperatures (12- 18%) and more constant salinity (29-34%). Our study also included Bennett Slough, a shallow (0.3-1.8 m) semi-enclosed embayment that is connected to Elkhorn Slough via a culvert (0.6 m diameter) at the north end of Moss Landing Harbor (Fig. 1). Substratum was soft mud, mean water temperature ranged from 10.5% in January to 21.5% in June, and mean salinity was constant, varying from 3Oo/oo in February to 330/w in June (Appiah 1977). SAMPLING METHODS Fishes were collected at least monthly from August 1974 to June 1976 at three locations in the main channel of Elkhorn Slough, approximately 0.6 km (the bridge station), 3.1 km (the dairy station), and 6.0 km (the Kirby Park station) inland, and at two locations on the sandy shelf (water depth = 5-10 m) north and south of the Moss Landing Harbor entrance (the ocean station; Fig. 1). At least

Fish Assemblages

monthly collections were taken in the main channel at the Hudson’s Landing station (about 10 km inland from the entrance of the slough) from January 1979 to June 1980 and in two tidal creeks (the Long Canyon and Rubis Creek stations) from October 1978 to June 1980. Fishes were collected about monthly in Bennett Slough from August 1974 to August 1976. Collections in the main channel were taken with a 4.8 m otter trawl (3.8 cm stretch-mesh body with 1.3 cm codend liner) towed at 3-4 knots behind a 5 m Boston Whaler for 5 min or 10 min into the current at flood tide. In tidal creeks, this gear was towed at 1.5-2.5 knots between fixed markers during daylight. Catch data from otter trawls were standardized to number of fish per 1 0-min tow for seasonal and spatial comparisons. Plots of cumulative number of species against a randomly pooled number of samples (collected at the dairy station from May to October, 1975 and 1976, a period of high species richness) indicated that six tows were adequate to describe spatial and temporal patterns in species composition and abundance in the slough environment (Cailliet et al. 1977). Collections in Bennett Slough were taken with a beach seine (15.2 m long with 0.6 cm and 1.3 cm meshes) fished along shore for an average of 30 m per haul to a maximum depth of 1.3 m. In areas of the tidal creeks that were < 1.5 m in depth, fishes were collected periodically with beach seines and channel nets made of 3-6 mm* mesh nylon, similar to those of Bozeman and Dean (1980). At highhigh slack tide, 8-10 channel nets were placed across creeks and tributaries, lead line forced into the sediment and ends secured above the channel bank. Fishes were collected as tidal level dropped and nets were exposed. Catch data from beach seines and channel nets were expressed as number of fish per haul. Fishes were identified, counted, measured to the nearest mm in standard length (SL), and either released or preserved with 10% formalin. Abundance (mean number of fishes per species per tow), species richness (mean number of species per tow), and dominance (D = Z PIP, where Pi is the proportional abundance of species i per tow) were evaluated by location for each season. The index of dominance measures unevenness of species abundance within an assemblage, gives relatively little weight to rare species, and ranges from 1 x s-l (where s = total number of species) to 1 (total dominance by one species). Seasons were defined as fall (August, September, October), winter (November, December, January), spring (February, March, April), and summer (May, June, July). These groupings approximated the climatic seasonality of the study area in terms of rainfall, air

-_ (

in Elkhorn Slough, CA

467

MAP OF CALIFORNIA

\ \ \

Fig. 1. Fish sampling locations (0) in Elkhorn and Bennett sloughs, California, and the adjacent nearshore ocean.

and water temperatures, and salinity (Broenkow 1977). Species composition was compared between stations using the percentage similarity index (PSI; Krebs 1989): PSI = C

minimum(p,,,

ppi)

where PSI is the sum of the smallest percentage by number (pli and ppi) of each pair of species i from stations 1 and 2, respectively. This index ranges from zero (no similarity) to 1.00 (identical species arrays). In the present study, PSI values greater than 0.60 were interpreted as significant, based on level of significance of product-moment correlation coefficient relative to PSI’s (Cailliet and Barry 1978). Each species was categorized (modified from Lenanton and Potter 1987; Loneragan et al. 1989) as either (1) a slough resident (R; spawns and completes entire life cycle in the slough); (2) a partial resident (PR; primarily lives in the slough, seasonally or ontogenetically moves to the ocean, and returns to reproduce in the slough); (3) marine immigrant (MI; primarily lives in the ocean and

466

M. M. Yoklavich et al.

TABLE 1. Relative abundance (%), mean number per IO-min tow (n), standard error (in parentheses), and life style (M = marine, MI = marine immigrant, R = slough resident, PR = partial resident, and F = freshwater) of fish species caught in otter trawls at six locations in Elkhorn Slough and at two nearshore ocean stations. Only those species representing >O.l% overall abundance are included. Overall abundance and rank are indicated. Dash (-) indicates species was not collected. OC.Xll

TaXOn

Amphistichus argenteus (M) Atherinops @nis

(PR)

Atherinopsis calij&niensis (PR) Citharichthys stigmaeus (MI) Clevelandia ios (R)

Cymatogaster aggregata (PR)

2.74 (0.55) -

0.46 (;.;;)

Damalichthys vacca (MI)

(0:06) -

Dorosoma petenense (F) (R)

0.01 (0.01) -

Engraulis mordax (MI)

-

Gobiidae Hyperfirosopon anale

1.76

(M)

Hyperprosopon argenteum (MI) Hyfisopsetta guttulata (MI)

Lepocottus arm&us (R) Micrometrus minimw

(M)

Morone saxatilis (F) Mustelus calijkicus

(M)

Myliobatis cal$rnica

(PR)

Neoclinus uninotatus (M) Ophiodon elongatus (M)

(PR)

(M)

Porichthys not&us (MI) Psettichthys melanostictus (M)

21.9

(;.;p

(;:;;)

(7.;;) (0168) 2.37 (0.55)

1.14 (1.14) 0.03 (0.03) 21.54

(0:03) -

3.7 0.6

90.94 (6yJ3 (0:55) -

0.1 14.1 0.6 0.3 -

-

-

(;.;;)

-

-

(0:20) 0.64

Platichthys stellatus (MI)

4.6

-

0.01 (0.01) -

n

96

0.03 (0.03) 0.01 (0.01) -

(OO:;;)

(MI)

Pleuronichthys decurrens

(;:;:)

0.22

Paralichthys calijknicus (MI)

Phanerodon furcatus

(i.;;)

(0:02) -

Lepidogobius lepidus (R)

Parophrys vet&s

0.57 (0.27) -

-

Clupea pallasii (MI)

Embiotocu jacksoni

Bridge

”

0.2 0.1

30.49 (7.02) 0.66 (0.66) 1.63 (0.77) 0.17 (0.12) 2.06 (y.;;) (0:40) -

0.1 1.8 0.1 4.2 4.6 5.1 8.6 19.0

0.14 (0.06) 0.40 (;.;;) (0:15) 0.03 (;.;;) &) ($ (1:09) 0.23 (;.:;) (0:23) -

Dairy ”

%

0.5 90% of all fishes taken in trawls throughout the study; relative abundance of these species ranged from 0.8% for Psettichthys melanostictus

96

0.10

0.2

(8.;;)

0.8

(p;)

0.3

(y:;;)

2.5

(($9

0.8

$“:)

0.6

(0:29) -

-

co.1 co.1

0.7

”

0.04 (0.03) 0.16

’

0.1 0.2 0.2

(sandsole), occurring only at the ocean station, to 29.4% for Cymatogaster aggregata (shiner surfperch), which was abundant at all stations. The highest abundance and species richness occurred at the bridge station, where a mean density of 209 fish per lo-min tow and 37 species were collected in 35 tows (Table 2). The relatively high standard error (SE = ,82.4) is largely due to 1,208 C. aggreguta from a single collection during an intense episode of red tide. The large number of individuals and species likely reflects increased diversity of available habitat at the bridge station, including submerged rocks and pier pilings. Species more typical of rocky coastal marine habitats were collected in low numbers at the bridge station, including Artedius harringtoni (scalyhead sculpin), Coryphopterus nicholsii (blackeye goby), Hexagrammos decagrammos (kelp greenling), Hypsurus caryi (rainbow surfperch), Neoclinus uninotutus (onespot fringehead), Ophiodon elongatus (lingcod), Scorpaenichthys marmorutus (cabezon), and juvenile Sebastes, especially S. auriculatus (brown rockfish), S. mystinus (blue rockfish), S. paucispinis (bocaccio), and S. rastrelliger (grass rockfish; see Cailliet et al. [ 19771 for the abundance of less common species). The ocean station and tidal creeks (Long Canyon and Rubis Creek stations) consistently had the lowest mean densities (12.5, 11;5, and 38.7 fish per lo-min tow, respectively, Table 2). The other three stations (i.e., dairy, Kirby Park, and Hudson’s Landing) along the main channel were interme-

Fish Assemblages TABLE

1.

Continued.

Kirby Park n

0.10 (0.05) -

Hudson’s %

”

Landing

Rubis Creek

Long Canyon ”

%

Overall

n

”

%

Rank

-

0.10

0.2

24

0.1

0.47

0.7

11

0.2

0.08

0.1

31

0.6

0.39

0.6

13

0.15

0.2

24

-

0.09

0.1

31

0.2

0.06

0.1

31

-

0.10

0.2

24

1.6

0.14

0.2

24

-

1.5

0.12

0.2

24

3.7

4.0

0.36

0.6

13

-

0.04

0.1

31

-

-

-

%

-

%

0.06

0.1 -

0.20 (0.13) -

0.27 (;.;:)

471

in Elkhorn Slough, CA

0.3

co.1

-

0.3 0.2

0.22 (0.15) -

0.2

0.29 (0.18) -

0.3

-

-

1.09 (1.08)

-

0.12 (0.10)

-

0.43 (0.22) -

1.0

0.60

-

-

(0:09)

diate in fish abundance. Species richness was highest at the three stations closest to the entrance of the slough (i.e., ocean, bridge, and dairy) and at the Rubis Creek station; overall dominance indices were lowest at these stations (Table 2). Species composition of otter trawl catches was most similar between the bridge station and the other two stations in the main channel of the lower and middle region of Elkhorn Slough (i.e., dairy and Kirby Park, Table 3), largely because of the numerically dominant C. aggregata and other surfperch species. Fish assemblages at the most shallow inland station of the main channel (Hudson’s Landing) and at the tidal creek stations (Rubis Creek and Long Canyon) were more similar to each other than to assemblages at any other station in the main channel. Species composition was most unique at the ocean station and similarity (PSI) to the other

TABLE 2. Summary of diversity, dominance, and at two nearshore ocean stations.

and abundance of fishes captured with otter trawls at six stations in Elkhorn Slough

Y;$

Hudson’s Landing

Long Canyon

Rubis Creek

37 0.19 3,244

26 0.32 3,807

24 0.37 4,479

20 0.29 596

32 0.22 1,933

22,334

66.2

77.7 (15.3)

101.8 (21.8) 44

11.5

38.7

63.0

(1.7) 52

(9.6) 50

355

OC.2ZUl

Bridge

Dairy

Number of species Dominance index Total number

34 0.12 950

37 0.26 7,326

Mean number tow-*

12.5

(SE) Number of tows

(1.6) 76

209.3 (82.4) 35

p Adjusted to IO-min tows.

stations decreased progressively with distance inland and into the ti’dal&eeks. ’ Dominant species at each site varied with distance inland (Table 4). Of the eight most abundant species taken at the ocean station, four were nonestuarine species not collected at any slough station, and representing nearly 50% of the total abundance at this station. Two abundant species were restricted to the ocean, bridge, and dairy stations. Notably, Citharichthys stigmaeus (speckled sanddab), ‘the dominant species at the ocean station, and Phanerodonfurcutus (white surfperch) were much less abundant east of the dairy station. Cymutoguster uggregutu was numerically dominant at lower and middle slough stations of the main channel and in Rubis Creek. Leptocottus arm&us (staghorn sculpin), a euryhaline cottid, was highest in abundance at stations furthest inland, and was the dominant spe-

(2.0) 49

49

OVerall

65

472

M. M. Yoklavich et al.

TABLE 3. Comparison of fish species composition in otter trawl collections from six stations in Elkhorn Slough and two adjacent ocean stations based on percentage similarity index (PSI). Comparisons with the fish assemblage from beach seine collections in Bennett Slough also are indicated.

Ocean Bridge Dairy Kirby Park Hudson’s Landing Rubis Creek Long Canyon

Bridge

Dairy

Kirby Park

0.30 -

0.25 0.77 -

0.17 0.60 0.48 -

ties in trawls at the Hudson’s Landing and tidal creek stations. Engraulis mordax (northern anchovy) and Clupea pallasii (Pacific herring) also were numerically dominant in otter trawls at the shallow inland stations. For beach seine and channel net collections from the smallest tidal creeks (Table 5), overall species richness was only 16 (< 10 species in the shallowest creeks) and dominance was higher (0.45-0.60) than in the main channel. Dominance indices increased because of the high relative abundance of juvenile Atherinops a&is (topsmelt, 62.7%). Clevelandia ios (arrow goby) and E. mordax also were relatively abundant (12.1% and 11.6%, respectively) in beach seine and channel net collections from the upper marshes. Seasonal variation in fish abundance was high, with a noticeable depression in mean catch rate during the winter and early spring at most stations (Fig. 2). The exceptionally high peak in abundance at the bridge station during winter 1978 was caused

HUdSOIl’S Landing

Rubis Creek

Long Canyon

0.11 0.32 0.36 0.45 0.61 -

0.11 0.16 0.18 0.32 0.62 0.66 -

0.05 0.07 0.11 0.27 -

Bennett

Slough

0.08 0.12 0.14 0.28 0.30 0.35 0.42

by one large catch of C. aggregata. Peak abundance occurred in summer at most stations throughout the slough. Mean species richness per tow also decreased during winter (Fig. 3). Species collected in winter largely were slough residents (see Cailliet et al. [ 19771 and Barry [ 19831 for monthly speciesspecific catch rates). Seasonal patterns in mean dominance indices generally were opposite those in abundance and species richness, with peaks in winter and early spring months (Fig. 3). Trends in dominance were most apparent at the ocean station and lower slough stations (i.e., bridge and dairy) in the main channel. During spring and summer, most species were present as juveniles, while some were collected in low numbers as reproductively active adults, including C. pallasii, C. aggregata, Embiotoca jacksoni (black surfperch), Triakis semifasciata (leopard shark), and Myliobatis cal@rnica (bat ray). Juvenile fishes contributed to the increase in abundance and species richness during this period, and many of

TABLE 4. Relative abundance (%) of dominant species totaling 80% (or greater) of the fishes collected in Elkhorn and Bennett sloughs and at adjacent nearshore ocean stations. See legend of Table 1 for coded life-style categories (in parentheses). Species

Ocean

Psettichthys melanostictus (M) Hyperprosopon anale (M) Pleuronichthys decurrens (M) Amphistichus argenteus (M) Citharichthys stigmaeus (MI) Phanerodon furcatus (PR) Parophrys vet&s (MI) Platichthys stellatus (MI) Cymatogaster uggregata (PR) Embiotoca jacksoni (R) Leptocottus armatus (R) Engraulis mordax (MI) Clupea pallasii (MI) Seriphus politus (MI) Atherinops u$nis (PR) Clevelandia ios (R) Triakis semi&c&a (PR)

19.0 14.1 8.6 4.6 21.9 4.6 4.2 5.1

Total (X) Number of dominant species

82.1 8

Bridge

Dairy

10.3 16.6

4.4 28.4 4.0 3.9 28.8 13.4

43.4 14.6

Kirby Park

10.7 5.9 53.7 13.1

84.9 4

82.9 6

Hudson’s Landing

83.4 4

Long Canyon

Rubis Creek

5.9

57.6 18.3 15.0

90.9 3

3.7 51.2

B.3lll.% Slough

22.0 15.5 7.7 41.1 9.2 3.8

9.5 4.9 3.7 3.7

4.0

82.6 7

81.3 6

23.7

34.9 80.6 3

473

Fish Assemblages in Elkhorn Slough, CA

TABLE 5. Number (Number = mean per sample and Percent = relative abundance) of fishes caught in beach seines in Bennett Slough from August 1974 to August 1976, and in beach seines and channel nets at the most shallow stations of Elkhorn Slough (i.e., Long Canyon, Rubis Creek, and Hudson’s Landing) from October 1978 to June 1980. See legend of Table 1 for coded lifestyle categories (in parentheses). BennettSlough TaXOIl

Acanthogobiusjlauimanus (R) Atherinoj~ a&is (PR) Atherinopsis calij&aiensis (PR) Clevelandia ios (R) Clupea pallasii (MI) Cottus asper (F) Cymatogaster aggregata (PR) Embiotoca jacksoni (R) Engraulis mordax (MI) Eucyclogobius newberryi (R) Gasterosteus aculeatus (F) Gillichthys mirabilis (R) Gobiidae Hyperprosopon argenteum (MI) Hypomesus pretiosus (M) Hypsopsetta guttulata (MI) Lepidogobius lepidus (R) Leptocottus armatus (R) Mugil cephalus (R) Paralichthys calij%rnicus (MI) Phanerodon furcatus (PR) Platichthys stellatus (MI) Porichthys notatus (MI) Syngnathus leptorhynchus (R) Triakis semi&sciata (PR) Urolophus halleri (M) Mean number of fish sample-’ Total number of fish Number of species Number of samples

Number

Elkhorn Slough P.STCellt

0.3 1.5 0.6 20.6 0.6