NOAA Technical 

JUNE 1985 

ALBACORE FISHING AND WINDSPEED 

Paul N. Sund 

NOAA-TM-NMFS-SWFC-53 

3 

U.S. DEPARTMENT OF COMMERCE 

National Oceanic and Atmospheric Administration 

National Marine Fisheries Service 

Southwest Fisheries Center 
NOAA Technical Memorandum NMFS 

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c' 
NOAA Technical Memorandum NMFS 

This TM series IS used lor documentation and timely communicallon 01 prelfrninary results. imterlrn reports. Or 

special purpose mlormalion, and have not received complete lormal review. editorial conlrol. or detailed edhing 

JUNE 1985 

ALBACORE FISHING AND WINDSPEED 

Paul N. Sund 

Southwest Fisheries Center 

National Marine Fisheries Service 

Pacific Environmental Group 

P.O. Box 831 

Monterey, California 93942 

NOAA-TM-NMFS-SWFC-53 

U.S. DEPARTMENT OF COMMERCE 

Malcolm Baldrige. Secretary 

National Oceanic and Atmospheric Administration 

Anthony J. Calio, Deputy Administrator 

National Marine Fisheries Service 

William G. Gordon. Assistant Administrator for Fisheries 
CONTENTS 

Page 

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

Replies to questionaire ................................... 4 

JIGBOAT FISHING AND WIND...................................... 4 

BAITBOAT FISHING AND WIND..................................... 7 

A WIND-FISHABILITY INDEX...................................... 7 

SUMMARY AND CONCLUSIONS....................................... 17 

ACKNOWLEDGEMENTS.............................................. 18 

'REFERENCES.................................................... 18 

Table 1. Statistical values for the relationships between 

jigboat length and windspeeds at which operations 

stop while "on fish" and while Itoff fish"... ........ 7 

Table 2. Percent of fishing time lost per month (hypothetical) 

for specified areas, 1979 to 1981................... 10 

Table 3. Comparison of frequencies and percentages of days 

fished by U.S. albacore jig and bait vessels in 

the north and south coastal areas at windspeeds 

ranging from calm to over 30 knots. Data from logbook records of average daily windspeed during 

fishing seasons of 1977 to 1981..................... 11 

Table 4. Comparison of percent frequencies of windspeeds 

in speed classes during months of fishing seasons. 

Data from jigboat fishing logbooks (Logs), FNOC 

computed winds (FNOC), and U.S. Navy Climatic 

Atlas (Atlas). ..................................... 12 

Table 5. Computed windspeeds in areas and at times where 

fishing was reported to have been stopped due to 

adverse winds..................................... 13 

Table 6. Summary of windspeeds recorded on chartered fishing 

trips during which conditions were noted to be 

)I rough1! or "unworkabl ell ........................... 14 

c Table 7. Revision of Table 2. Percent of fishing time lost 

per month (hypothetical) for specified areas, 1979 

to 1983........................................... 16 
Figure Captions: 

Figure 1. 

Figure 2. 

Figure 3. 

Figure 4. 

Figure 5. 

Figure 6. 

Figure 7. 

Fishing areas within the U.S. albacore fishery. 

Frequency distribution of lengths of albacore vessels 

responding to the questionaire. 

Relationship between jigboat lengths (x-axis) and windspeeds 

at which fishing was reported to stop (y-axis). Regression 

lines for all areas combined and different areas within the 

fishery (see fig.1) are included. PNW=Pacific northwest 

offshore; NC=north coastal: SC=south coastal; All=all areas 

combined. 

f 

m 

Regressions describing relationships between jigboat vessel 

lengths and windspeed at which operations stop when fishing 

(Iton fishll) and when not fishing ("off fish1#) . Relationships between baitboat vessel lengths (x-axis) and 

windspeeds at which fishing was reported to stop (y-axis). 

Regressioon lines for north and south coastal areas combined 

(All) and for north and south coastal areas. 

Relationship between windspeed at which jigboat fishing was 

stopped while ("on fish'@) and the cumulative frequency 

(percent) of those reported wind speeds. Regression plotted 

is a linear approximation of the relationship. Data from 

replies to questionaire. 

As per figure 6. Data from charter vessel daily log sheets. 
ALBACORE FISHING AND WINDSPEED 

by Paul N. Sund 

Pacific Environmental Group 

Southwest Fisheries Center 

P.O. Box 831 

Monterey, CA 93942 

INTRODUCTION 

It is a general supposition that albacore fishing operations 

are subject to weather conditions. Attempts to determine the effect 

of index 

using environmental data from log books of albacore fishing vessels 

have been unsuccessful (Sund, 1984). Such an index could be used as 

input to albacore modelling efforts (Weber, 1982) to investigate the 

effect of an environmental factor on the interpretation of 

catch-effort. A possible reason for the failure was the fact that 

windspeeds ltcalmll, Itless than lo1@, Ill0 to 20", "20 to 30", and Ilover 30" knots, which do 

not yield satisfactory resolution for such a study, particularly in 

the higher categories where the effect is anticipated. An alternate 

interpretation is that windspeed is not a factor on catch. The 

specific question remains as to how variations in weather conditions 

affect monthly and annual catch rates. 

windspeeds on catch rates and to develop a wind fishability 

are recorded on the fishing logs in categories of 

In order to further investigate the effect of windspeed on 

albacore fishing activities, a questionaire was mailed by the Western Fishboat Owners Association to its approximately 350 

fishermen-members. It specifically asked for information on the 

windspeeds at which operations are stopped on albacore fishing vessels 

of different sizes and types in four specified areas of the fishery: 

north and south coastal regions, Pacific northwest offshore region and 

Midway region (Figure 1) The questionaire was mailed early in 1984, 

and thus reflects recent experience. This report uses the results of 

the questionaire survey as the basis for considerations of the 

influence of windspeed on the ability to fish. 

It is recognized that windspeed, in itself, is not the single 

factor that determines fishable conditions for the albacore fleet. 

Fishability is determined by a combination of variables among which 

sea state probably represents the most important effect of wind. In 

addition, the direction of wind, sea and swell in relation to one 

another are expected to affect fishability. Interpretation of this 

complex of variables is beyond the scope of this study, which is 

limited to an attempt to describe the influence of windspeed as a 

single factor on albacore fishing. In the discussions that follow the 

assumption is made that the characteristics of the vessels that 

reported and their behavior with respect to wind and fishing is 

representative of the entire albacore fleet. 
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Figure 2. Frequency distribution of lengths of albacore vessels responding 

to the questionaire. 
REPLIES TO QUESTIONAIRE 

The principal questions asked in the questionaire were: * Windspeed at which you stop fishing when on fish ('Ion 

* Windspeed at which you stop operations when not on fish 

Replies were received from 87 persons. The distribution of 

fish") 

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replies by vessel type was: 

67 jigboats, 

14 baitboats, 

6 combination vessels 

1 j ig/gillnet , 1 bait/gillnet) . 

(4 jig/bait, 

The length frequency distribution of vessels that reported is 

illustrated in figure 2. Jigboats ranged in length from 37 to 75 feet 

with a mean length of 53 feet. The range in length of baitboats was 

42 to 65 feet; for combination vessels, 42 to 62 feet. 

No influence of wind on fishing operations of any vessel was 

reported for windspeeds below 20 knots. Some responses to the 

questionaire indicated that fishing took place in winds as high as 60 

and 70 knots (Figure 3). Reports of fishing in such high winds may be 

due to how the questions in the questionaire were interpreted 

(eg.reporting of gust values rather than steady winds) or due to 

erroneous estimation of windspeeds (eg.lack of instruments). 

Apparently, few vessels have instruments for accurate measurement of 

winds. 

JIGBOAT FISHING AND WIND: 

Sufficient numbers of replies were recieved to justify 

statistical treatment of the data only for jigboats. The most 

important question asked, in terms of potential application to the 

albacore model, was at what windspeed operations stopped while 

fishing. The relationship of vessel length and the windspeed at which 

jigboat fishing was reported to cease is plotted in figure 3. 

Intuitively, one would anticipate larger vessels to be able to fish in 

higher winds. Indeed, such a relationship is evident, but there is a 

high degree of variability. Variability should be expected from 

subjective estimates of windspeed and also from vessels of varying 

characteristics, construction and sea-keeping ability, and also from 

varying tolerance to weather of individual operators. 

Regressions were calculated to determine differences in 

behavior of vessels of different lensths with respect to windspeeds at 

which activity stopped while Iton ?ish" or "off- fish" (figire 4). 

Statistical values for the rearessions are aiven in table 1. One 

might anticipate a tendency foracontinuation of -operations in higher 

winds when on fish than when off fish. Such a difference was found, 

but it was small and statistically not significant. The regression 

equation predicts that, for example, a 45 foot long vessel would stop 

fishing while on fish at 34 knots and it would stop at 30 knots while 

off fish. 

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Table 1. STATISTICAL VALUES FOR THE RELATIONSHIPS BETWEEN 

JIGBOAT LENGTH AND WINDSPEEDS AT WHICH OPERATIONS 

STOP WHILE "ON FISH" AND WHILE "OFF FISH". 

Activity Intercept Slope R-Square F-ratio 

- ON FISH 13.43 0.45 .18 13.01 ** 

OFF FISH 11.40 0.42 .26 22.51 ** 

** = significant at alpha = 0.01 

BAITBOAT FISHING AND WIND: 

Replies were received from 14 baitboats .which fished the north 

and south coastal areas. Most bait fishing was reported from the 

southern coastal area (13 vessels); seven boats reported fishing the 

northern coastal area. Figure 5 is a scatter plot showing the 

reported bait vessel lengths and the windspeeds at which fishing was 

stopped when on fish. Regression lines are included in the figure, 

but the data are too few to permit any conclusive statements to be 

made concerning the relationships for the different areas. The figure 

does reveal that none of the baitboats from which reports were 

received fished at windspeeds above 35 knots; and there is a trend 

indicating that larger vessels can operate in somewhat higher 

windspeeds than can smaller ones. The average size baitboat (56 feet) 

stops fishing when encountering windspeeds of about 25 knots. Any 

difference in fishing behavior of vessels in the two areas apparently 

is slight. 

A WIND-FISHABILITY INDEX: 

A regression was computed and plotted (Figure 6) relating the 

windspeeds at which jig fishing was reported to be stopped while on 

fish (x-axis) and the cumulative frequency (percent) of those reported 

windspeeds (y-axis). Obviously, this relation holds only for winds 

above approximately 20 knots, the minimum speed reported. The linear 

regression approximating the curvilinear relationship in figure 6 is 

where x = the windspeed at which fishing stops 

when "on fish", and 

reported windspeed. 

y = the cumulative frequency of the 

This relationship and the frequency distribution of windspeeds 

were used to compute the (hypothetical) percentage of time lost due to 

wind for sample times and areas within the fishery. These percentages 

- comprise the wind-fishability index. The index was computed for four 

sample areas that represent actively fished portions of the respective 

sub-regions of the fishery. The regression was used to compute the 

amount of lost time per day according to the frequency distribution of 

daily mean wind speeds. From these, monthly means were calculated. 
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Figure 6. Relationship between windspeed at which jigboat fishing was stopped 

while ("on fish") and the cumulative frequency (percent) of those 

reported wind speeds. Regression plotted is a linear approximation 

of the relationship. Data from replies to questionaire. 
The wind data used were daily mean windspeeds computed from six-hourly 

surface winds derived from the standard 63 by 63 FNOC grid of northern 

hemisphere pressure/wind fields (Anon., 1975). They represent wind 

conditions in areas three degrees longitude by three degrees latitude, 

centered at 33N, 125W (south coastal), 50N, 130W (north coastal), 45N, 

145W (Pacific northwest offshore), and at 45N, 170W (Midway). For 

these areas during the years 1979 to 1983 the hypothetical fishing 

time lost per month is given in table 2. Such computations are 

possible may be specified, depending on the interests of the investigator. 

for any area of the fishery or for any time period that 

Table 2. PERCENT OF FISHING TIME LOST PER MONTH (HYPOTHETICAL) 

FOR SPECIFIED AREAS, 1979 TO 1983. 

JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC 

AREA: 33N,125W: South Coastal 

1979 201100101002 

1980 173100000000 

1981 312114000000 

1982 210100000002 

1983 422210100013 

<......season.......> 

AREA: 50N,130W: North Coastal 

1979 4 4 5 11 0 0 0 2 71314 

1980 6 8 17 11 0 12 5 811 

1981 19 6 8 3 10 0 13 4 8 8 

1982 533220101335 

1983 18 9 5 3 0 11 0 14 7 4 

<......season.......> 

AREA: 45N,145W: Pacific Northwest Offshore 

1979 4 4 9 3 4 0 10 910 814 

1980 810 514 6 0 10 3 6 8 8 

1981 1212 8 5 5 4 0 4 7 416 6 

1982 10 311 9 4 0 11 2 8 814 

1983 181012 5 5 7 2 0 13 7 8 

<....season.....> 

AREA: 40N,170W: Midway 

1979 14 310 5 3 13 0 2 7 210 

1980 15101114 5 0 6 13 910 8 

1981 101417 4 4 3 11 2 2 813 

1982 8 7 4 2 5 12 0 3 8 710 

1983 5 614 2 3 5 12 3 310 8 

<..season..> 

The hypothetical loss of fishing time during the fishing season 

(duration varying with the particular sub-region of the fishery) is 

only on the order of zero to seven percent in the coastal areas, and 

up to ten percent in the offshore areas (Table 2). In the south and 

north coastal areas the percentages mostly are from zero to five 

percent, with only two higher values. In all four areas during months 

prior to and after the usus1 fishing seasons, windspeeds are such that 

percentages of lost fishing time may be in the teens. If windspeeds 

high enough to adversely effect fishing operations occur only seven 

percent of the time or less during the seasons, one is led to conclude 

that windspeed, in itself, is not a significant factor affecting catch 

in the coastal portions of the fishery. 
Two points of concern arise from the above results: (1) 

windspeeds reported for the stop-fishing conditions appear high 

relative to the resulting effect (e.g., according to the regression, 

only 50 percent of jig vessels stop fishing at 36 knots, 75 percent at 

45 knots, etc.) and (2) the percentages of lost time seem low relative 

to the incidence of reports of stoppages. Therefore, alternative 

means were sought to investigate these problems. 

Logbook data on windspeeds in which fishing occurred were 

compared for the fishery areas north and south of 40N for both jig and 

bait vessels (Table 3). In the three speed classes up to 20 knots, 

for percentages 

of records of fishing in the two areas. In the 20 to 30 knot speed 

class, the percentages for the vessel types differ, baitboats 

reporting fishing in winds of those speeds 'about 60 percent less 

frequently than jigboats. At windspeeds over 30 knots, the 

percentages essentially are identical for both types and areas. 

each type of vessel there is a consistent pattern in 

Table 3. COMPARISON OF FREQUENCIES AND PERCENTAGES OF DAYS FISHED BY 

U.S.ALBACORE JIG AND BAIT VESSELS IN THE NORTH AND SOUTH COASTAL AREAS 

RECORDS OF AVERAGE DAILY WINDSPEED DURING FISHING SEASONS OF 1977 TO 

1981. 

AT WINDSPEEDS RANGING FROM CALM TO OVER 30 KNOTS. DATA FROM LOGBOOX 

WINDSPEED(KTS) 

CALM <10 10-20 20-30 >30 

NORTH OF 40N 

Jigboat 

Baiitboat 

1502 (24%) 1406 (17%) 2296 (37%) 1143 (18%) 216 (3%) 

37 (39%) 21(22%) 26 (28%) 7 (7%) 3 (3%) 

SOUTH OF 40N 

Jigboat 

Baitboat 

For a 

over 30 knots 

1853(25%) 1693(23%) 2676(36%) 1007(18%) 210(3%) 

403(37%) 271(25%) 324(30%) 76 (7%) 18 (2%) 

large area of the north Pacific, the percentage of winds 

is approximately three percent of the total number 

(approximately 3,000,000 observations) of recorded winds (C. Nelson, 

personal communication). Also, winds of 30 knots and above are likely 

to adversely effect fishing. The percentages and distributions of 

windspeeds recorded by jig and bait vessels in the north and south 

coastal areas ( Table 3 ) are similar and the incidence of winds over 

30 knots is on the order of two or three percent in both areas. 

To further investigate whether windspeeds reported by the 

albacore fleet are representative of wind conditions in the fishery 

area, the percent frequency of winds in the various speed classes 

reported by jigboats was compared with two additional data sources: 

FNOC computed winds and those tabulated in the U.S. Navy Marine 

Climatic Atlas of the World (Anon.!1977). Locations were selected from 

the latter two sources to approximate the previously mentioned four 
centers of activity in the fishery. Percent frequencies of windspeed 

from the three sources are listed in table 4 for comparison. For the 

comparison, the log and FNOC data were grouped similarly, but the Atlas 

frequencies only could be grouped into speed classes that approximated 

the others. Log data were extracted only for the regions north and 

south of 40N. 

4 

Table 4. COMPARISON OF PERCENT FREQUENCIES OF WINDSPEEDS IN SPEED 

CLASSES DURING MONTHS OF FISHING SEASONS. Data from jigboat fishing 

logbooks (Logs), FNOC computed winds (FNOC), and U.S. Navy Climatic 

Atlas (Atlas). 

WINDSPEED (KTS) 

CALM <10 10-20 20-30 >30 

North coastal region 

Logs (N of 40N) 0 41 37 18 3 

FNOC (50N 130W) 0 44 39 13 3 

Atlas (#19) 0 33* 47* 18 4 

Logs (S of 40N) 0 48 36 18 3 

FNOC (33N 125W) 0 48 46 5* <1 

Atlas (#28) 0 45 41 6 <1 

FNOC 0 27 46 21 5* 

FNOC 0 32 44 20 4* 

South coastal region 

Pacific northwest offshore region 

Midway region 

Atlas 0 31 43 13 13 

Atlas 0 26 43 16 15 

The frequencies from the three sources generally are similar in 

most speed classes. Dissimilarities of apparent significance are 

noted in the table by means of asterisks and bracketing of the values; 

but no explanation for the differences is apparent. Some of the 

differences could be diminished by adjustment among adjacent speed 

classes (e.g., shifting 10 percentage points from the 20-30 to the 

10-20 class for the log data in the south coastal region, or similarly 

shifting 8 points from the >30 to the 20-30 class for the Atlas data 

in the Pacific northwest offshore region). But there is no obvious 

reason for doing so. Thus, the sampling of wind observations reported 

by the albacore fleet appears to be generally comparable to data from 

the other references, except as noted; i.e.,they encounter and report 

windspeeds with a frequency essentially the same as merchant vessels. 

Observations of stoppages of fishing due to winds in mid-season 

have been reported in the SWFC Albacore Bulletins and in the Annual 

Summary sections of the Annual Reports of the Pacific Marine Fisheries 

Commission. A sampling of noted times and areas of such occurrences 

was made for the 1984 season, and the computed windspeeds coincident 

with them were extracted from the FNOC environmental data records. 

These are combined in table 5. The windspeeds tabulated are those 

six-hourly FNOC values for the individual days at centrally located 

points within the areas of the fishery at which fishing was reported 

in either of the above media to be caused to stop due to high winds. 

It immediately becomes obvious that these windspeeds are significantly 
lower than most of those reported by fishermen responding to the 

questionaire. None of them were over 26 knots. A few examples of the 

stoppages are:(l) In the first three days of August between Morro Bay 

and Pt. Arena, 30 to 250 miles offshore, vessels were forced into 

port. The winds ranged from 17 to 24 knots (37N 123W). (2) At the end 

of August, 800 miles offshore of southern Oregon (45N,138W), boats 

left the area as winds increased. No winds above 15 knots are found 

in the FNOC records in late August; but winds of 15 to almost 18 knots 

occcurred there in the first days of September, and some records of 

winds up to 25 knots occurred there between the 6th and 14th of 

September. (3) Vessels fishing 300 to 350 miles west of the Columbia 

River left that area in the first few days of September because of 

rough seas and declining catches. Winds at 46N 130W in early 

September were below 15 knots except for two instances of 15 and 17 

knots on the 8th of September. (4) In the second week of September, 

effort was reduced due to strong winds between Cape Blanco and Point 

Arena (42N 124W). Winds there on the 10th and 11th were 16 to 20 

knots and between the 21 and 24th were 15 to 19 knots. (5) In late 

August and early September, from Pt Sur to San Francisco (37N 123W) 

fishing was affected by rough seas. Winds were of the range 15 to 22 

knots at the noted location. (6) On September 21 winds from Point 

Arena to Guide Seamount increased and forced many boats to port, where 

they stayed until the 24th. At 37N 123W in that period winds were 

between 15 and 21 knots. 

c 

Table 5. COMPUTED WINDSPEEDS IN AREAS AND AT TIMES WHERE 

FISHING WAS REPORTED TO HAVE BEEN STOPPED DUE TO ADVERSE WINDS. 

AREA: UT. LONG. Refer to number DATE COMPUTED WINDSPEED 

above 1984 Knots 

37 N 123 W 1 Aug 1-5, 17-23 

42 N 124 W 

45 N 138 W 

46 N 130 W 

Aug 30-31 15-22 

Sep 21-24 15-22 

Sep 10-11 16-19 

Aug 29-Sep 8 15-24 

early Sep <15-17 

In addition to the above incidents, daily logbook records 

maintained during chartered fishing trips during the past 12 years 

(1973-1984) by jigboats or longline vessels working jig lines were 

screened for notations of weather conditions adverse to fishing. 

Records noting rough or unworkable conditions are summarized in table 

6. Among these 146 records, none was found of winds over 45 knots, and 

fishing was reported to have been adversely affected when winds were 

in the 20 to 40 knot range. Fishing did occur under conditions noted 

as ltrough", "poorft, etc. in windspeeds from 10 to 45 knots. No 

consideration was made of the geographic distribution of these 

reports. 
TABLE 6. StmY OF WINDSPEEDS RECORDED ON CHARTERED FISHING TRIPS 

DURING WHICH CONDITIONS WERE NOTED TO BE "ROUGH" OR 

llUWORKABLEtl . 

WINDSPEED (KTS) 

10-20 30-30 >30 

ROUGH WHILE FISHING (n=130) 37 43 5 

FISHING NOT POSSIBLE (n=16) 2 5 9 

The above discussion makes it apparent that the regression used 

in figure 6 must be revised to account for the stoppage of fishing at 

windspeeds lower than those reported in responses to the questionaire. 

Therefore,data from the charter vessel day logs.were treated similarly 

to those from the questionaire in deriving a regression relating 

windspeed values to their respective cumulative frequencies. The 

resulting equation is: 

y = -61.53 + 4.87~ 

(Figure 7). This regression predicts that at winds of 20 knots, about 

35 percent of the jig vessels would stop fishing. Similarly,at 25 

knots, 60 percent would stop; at 30 knots, 85 percent would drop out; 

and at 40-45 knots, essentially all vessels would stop working. 

Using the latter equation to compute the fishability index, the 

percent of lost fishing time per month due to the effect of wind, has 

been re-computed (Table 7). The results continue to show that, for 

the sample areas and times, wind is of minor consequence to fishing 

during the seasons of the two coastal fisheries. Lost fishing times 

(hypothetical) are of significant levels during months prior to the 

beginning of the seasons in all four areas, and they also are of 

significant levels at the ends of the seasons. The latter point is 

reinforced by reports made anecdotally in the Annual Reports of the 

Pacific Marine Fisheries Commission that the onset of winter storms, 

which occur with short time intervals between events, causes the 

fishing season to close. This particularly is common in the north 

coastal fishery, but proceeds to southern areas over time as adverse 

winds progress southward (Sund, 1984. 35th Annual Tuna Conference. 

Poster). It is not possible to distinguish whether the principal 

factor of 

events (or equivalently, the low ratio of good to bad fishing weather) 

or the speed of the wind in any given event. In the two offshore 

areas of the fishery (Midway and Pacific Northwest offshore),levels of 

lost fishing time during months of the respective seasons at times are 

considerable (e.g. up to 28 percent). 

that precipitates the close of the season is the frequency 
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Figure 7. As per figure 6. Data from charter vessel daily log sheets. 
Table 7. REVISION OF TABLE 2. PERCENT OF FISHING TIME LOST PER MONTH 

(HYPOTHETICAL) FOR SPECIFIED AREAS, 1979 TO 1983. 

JAN FEB MAR APR MAY JUN JUL AUG SEP OCT 

AREA: 33N 125W: South Coastal 

1979 10 7 5 9 8 8 5 3 5 3 

1980 62217 8 4 3 0 2 0 1 

1981 12 6 9 9 917 2 4 4 1 

1982 8458623172 

1983 14 9 911 7 4 5 13 3 

<......season........> 

AREA: 50N 130W: North Coastal 

1979 171618 5 4 13 0 815 

1980 20 27 7 25 7 3 1 6 10 16 

1981 44 19 23 13 5 5 4 7 11 10 

1982 17 12 10 10 11 1 5 '3 4 10 

1983 452919 8 14 3 2 414 

<......season........> 

NOV DEC 

08 

23 

56 

38 

7 10 

29 37 

27 31 

24 23 

11 16 

28 15 

AREA: 45N 145W: Pacific northwest offshore 

1979 18 18 28 15 15 4 9 1 27 26 21 35 

1980 28 27 24 41 23 2 7 1 12 24 28 26 

1981 33 35 28 18 22 17 3 14 24 17 37 20 

1982 34 13 32 28 15 5 7 8 11 28 29 40 

1983 46 31 34 18 19 26 10 4 8 15 28 27 

<.....season....> 

AREA: 40N 170W: Midway 

1979 41 12 32 17 17 8 10 2 12 19 12 28 

1980 37 29 33 40 19 5 20 9 16 28 30 25 

1981 34 39 47 15 19 11 8 04 9 11 26 37 

1982 27 25 14 10 17 7 12 2 10 25 24 31 

1983 19 21 39 11 13 21 8 8 15 16 31 26 

<..season..> 

In summary, for the hypothetical cases illustrated, windspeed 

evidently is not a major factor on fishing in the coastal areas except 

during the beginning and ending months of the seasons. Windspeed is 

of greater significance in the two offshore regions. Within the 

seasons for those regions, the fishing time lost per month ranges from 

under five percent to about 28 percent. Thus, the use of the wind 

fishability index in fishery modelling studies should be an important 

factor for those offshore areas at least. Furthermore, the index 

values may indicate a different degree of influence if longer time 

series are used and/or if the geographic areas are defined 

differently. 
SUMMARY AND CONCLUSIONS: 

Fishing operations must cease at some "high" windspeed, and it 

may be supposed that large vessels should be able to fish at 

windspeeds higher than can small ones. Such relationships are evident 

from scatter diagrams and regressions computed from the data resulting 

from the questionaire. Windspeeds at which operations are cut off 

generally increase with vessel length. Differences in this 

relationship among four areas within the U.S. albacore fishery are 

evident, but there are insufficient data to test the differences 

statistically. 

There is a consistent difference of about five knots in cut-off 

windspeeds for j igboats in "on f ishtt and "off f isht1 circumstances. 

This suggests that fishermen will "tough it outll in somewhat higher 

wind conditions when on fish than when not fishing. 

None of the baitboats responding to the questionaire reported 

fishing at windspeeds above 35 knots. The" average" bait vessel (56 

feet) stops fishing at about 25 knots of wind. Larger baitboats fish 

in higher winds than do smaller ones. No major difference is evident 

in the behavior of baitboats fishing the two coastal areas north and 

south of 40N. 

Based on questionaire replies, both jigboats and baitboats can 

fish satisfactorily in winds up to about 20 knots. Baitboat fishing 

declines more in the 20 to 30 knot range of windspeeds than does 

jigboat fishing. Only two to three percent of fishing activity 

occurred at windspeeds above 30 knots for both vessel types. This 

approximates the frequency of occurrence for winds of those speeds in 

the climatic atlas and FNOC files. 

There is no evidence from responses to the questionaire of an 

adverse effect of wind on jigboat fishing operations below windspeeds 

of about 20 knots. However, information from chartered vessel logs 

and from computed winds at times and places at which fishing was 

reported to have been stopped due to high winds indicates that fishing 

can be stopped by winds from as low as 10 to 15 knots up to 45 knots. 

Computed winds for sample areas and times indicate that 

windspeeds have the potential for being a factor in determining 

fishable conditions within the four regions; and windspeed seems 

important regarding fishability as the end of the fishing season 

approaches in particular. 

I have attempted to estimate the percent of jigboat fishing 

time that may be lost due to wind conditions. This is based on the 

frequency distribution of windspeeds at which jigboats reported that 

they stopped fishing due to adverse wind conditions. Examples of lost 

fishing time per month for the four regions of the fishery are given 

as a wind-fishability index. Because of the large and not completely 

understood disagreement between the index based on questionaire 

results (Table 2) and the one based on other sources resulting in 

adjusted index values (Table 7), it may be advisable to consider this 

index as a qualitative rather than quantitative measure of monthly 

variation in fishability. The adjusted index is preferred because it 

* 
is based on a greater number of observations with less variability, 

and because it better conforms to what I understand to be a general 

impression that weather does at times significantly affect fishing 

effectiveness. 

Environmental data sources used to construct the index tables 

are available for more extensive time periods and alternately defined 

areas. The index set presented here may thus be readily extended or 

modified for application to models of the fishery in order to 

investigate the influence of wind on catch or catch/effort, or to 

compare such influence among selected time and area strata. , 

ACKNOWLEDGEMENTS 

The direction in which this project proceeded was significantly 

influenced by discussions with Dr. Richard H. 'Parrish and Mr. Andrew 

Bakun. Their suggestions and guidance are recognized and appreciated. 

Ms Donna Mallicoate performed the analysis of variance tests on the 

similarities/differences of regression curves in Figure 3. Drs. 

Douglas McLain, Roy Mendelssohn and Mr. David Husby gave generously 

of their time in assisting me with computer programming. 

Responsibility for any errors remains with the author. 

REFFERENCES 

Anonymous 

1975. U.S. Naval weather Service Numerical Environmental Products 

Manual. NAVAIR 50-1G-522. 1 June 1975. 

Sund, P.N. 

1984. Preliminary evaluation of albacore tuna fishing, wind and 

selected variables. Administrative Report PEG-84-1. 

Weber, E.C. 

1982. A sensitivity analysis of the Pacific albacore model. Working 

paper for the 7th North Pacific Albacore Workshop, May 20-25, 1982. 

Southwest Fisheries Center, La Jolla, CA 92038. 

. 
RECENT TECHNICAL MEMORANDUMS 

Copies of this and other NOAA Technical Memorandums are available from the National 

Technical Information Service, 5285 Port Royal Road, Springfield, VA 22167. Paper copies vary in 

price. Microfiche copies cost $3.50. Recent issues of NOAA Technical memorandums from the 

NMFS Southwest Fisheries Center are listed below: 

NOAA TM-NMFS SWFC 43 

44 

45 

46 

47 

48 

49 

50 

51 

52 

Atlas of airborne sea surface temperature observations in 

nearshore California waters, 1980-1983. 

P. N. SUND 

(July 1984) 

Potential impact of deep seabed mining on the larvae of 

tunas and billfishes. 

W. M. MATSUMOTO 

(July 1984) 

Sampling commercial rockfish landings in California. 

A. R. SEN 

(July 1984) 

Histopathological manual for monitoring health of striped 

bass in relation to pollutant burdens. 

J. A. WHIPPLE, M. JUNG, R. B. MacFARLANE and 

R. FISCHER 

(August 1984) 

Hawaiian monk seal population research, Lisianski Island, 

1982. 

H. S. STONE 

(August 1984) 

Interpreting spotted dolphin age distributions. 

J. BARLOW and A. A. HOHN 

(August 1984) 

Observations of the Hawaiian Monk Seal on Laysan Island 

from 1977 through 1980. 

B. W. JOHNSON and P. A. JOHNSON 

(October 1984) 

Hawaiian Monk Seal observations on French Frigate Shoals, 

1980. 

P. A. JOHNSON and B. W. JOHNSON 

(October 1984) 

Estimating dolphin juvenile survival rates from the proportion 

of calves nursing. 

T. POLACHECK 

(October 1984) 

Operational plan for NMFS albacore program. 

R. H. PARRISH, et al. 

(May 1985)