Fishery bulletin of the Fish and Wildlife Service - NOAA

More documents

Recommendations

Info

SALMON RUNS OF THE COLUMBIA EIVEE IN 1938 Ill 1928). Fairly good data are available as to the aggregate troll catch of chinooks and silvers in Alaska, Oregon, and Washington. The percentage of Columbia River fish in this catch, however, undoubtedly varies greatly during the season. There are no satisfactory data on this latter point. Even though we knew the proportions of Columbia Eiver fish in the catch at different times and in different localities, it would be impossible to allocate these to the seasonal runs of the Columbia and thus, eventually, to determine the element in the troll catch derived from the runs to the Columbia River above Rock Island Dam. Likewise, we have no data on the catch of the sport fishery or on that part of the Indian catch that is not sold. All of these elements increase to some unknown extent the economic importance of the salmon runs with which we are here concerned. TABLE 7.—Estimates and counts offish passing Bonneville, 1938 [The figures up to and Including May 7 are estimates based on partial counts only. Differences between the figures given hero and those In the report by Calkins, Durand, and Rich are due to the fact that this table includes the final figures as given by the Army Engineers, in which minor corrections were made of the figures submitted weekly.] Week ending Fob 19 Feb. 26 Mar 5 Mar 12 Mar 19 Mar 26 Apr. 2 Apr. 9 _.. Apr. 16 ... Apr. 23 Apr. 30 May 7 ... May 14 May 21 May 28 . June 11 June 18 June 25 July 2 July 9 July 16 July 30 Chinook 4 68 84 0 14 339 402 484 1,545 3,359 12 930 6 097 3,827 205 1,981 2 932 2,230 1,240 884 1,855 1 753 Grilse' 1 357 842 871 £3 710 615 334 164 102 204 430 Steelhead 55 158 204 980 1 267 84 981 7,319 1,927 639 320 138 3 217 1 622 1 644 164 632 652 620 641 800 4,061 б) 667 Blueback 131 672 318 24 153 1,358 6,719 15,441 16,491 21, 673 2,770 -- Silver Chum Week ending Aug. 6 . .. Aug. 13 Aug. 20.... Aug. 27 Sept. 3 Sept. 10 „ Sept. 17 Sept. 24 Oct. 1 .. . Oct. 8 Oct. 16 Oct. 22- . Oct 29 Nov. 6 Nov. 12 Nov 19 Nov. 26 Dee. 3 Dec. 10 Dec. 17 Dec. 24 Dec. 31 Chinook 1,327 4,163 5, 104 ' 10 112 53 753 SO 693 63 224 12,258 2 067 994 489 161 234 208 47 299 6 21 202 Total.. 277, 665 Grilse ï 329 769 1,010 2 166 9 452 8 913 5 756 1 681 406 244 99 34 17 40 10ß11Б000 36, 757 Steelhead 4,886 6,086 6,457 6 908 17 689 16 814 13 744 3,935 1,204 857 604 230 253 152 90 60 68 30 43 18 1 « 120, 985 Blueback 1,125 621 279 209 156 76 71 10 101 1 Grilse, locally designated as "jack" salmon, are precocious males. These are included in the preceding column headed "Chinooks," the figures in which are, therefore, the totals for this species. In table 7 are given the counts and estimates of the number of salmon and steelhead passing Bonneville Dam during 1938. Actual counting did not begin until May 7, but estimates could be made from partial counts—the so-called "spot" counts— covering the period from the middle of February to and including May 6. These partial counts were made by observers stationed for portions of the day at the several fish ladders. The records consisted of (1) the length of time during which the observations were continued, and (2) the number of fish of each species observed. This is essentially a sampling method, and it is known that the fish do not run uniformly during the entire 24 hours, or even during the daylight hours. A fairly good estimate can be made from such records, however, if the hours during which the fish run are determined with care, and if the periods during which the counts are made are suitably distributed. The method adopted here for estimating the total number for the day from the partial counts is to multiply by 12 the average hourly count as determined from the records. This is the method recommended and used by Fred Morton, who 311 0 200n oooo 75,040 Silver 0 115 6 9IJ4 4 760 1 933 239 56 94 389 240 212 138 18g417000 15 185 Chum 0 2 68 179 945 174 236 225 202 45 46 131 0 2 136
112 FISHEBY BULLETIN OF THE FISH AND WILDLIFE SERVICE was actively in charge of the count. This method assumes that the fish are passing over the ladders for 12 hours per day at the same average rate as observed during the period of the count and has been applied to each ladder separately and the sum is the estimated total for the day. For periods during which no count was made a linear interpolation between the preceding and the following days' estimated counts was used. Although not comparable in accuracy to the actual count, these estimates appear to give a reasonable basis for further calculations. A chief source of error in these counts and estimates is undoubtedly the identification of species as the fish were passing up the ladders. After May 7, when the actual count began, the fish were forced to pass through a small opening in a wen* placed across each fish ladder and over a submerged platform painted white. Identification of species under these conditions can be made with some accuracy by careful observers and, in general, reasonable confidence can be placed in the identifications so made. Those made under less favorable conditions must, necessarily, be accepted as the best available. Circumstances may arise in which a particular misidentification is especially likely to occur, in which case it may be recognized and steps taken either to improve the identification or to determine its influence and allow for it in the estimates of the number of fish of the species confused. 'It is apparent that one such particular case of misidentification might easily arise during the time when the blueback run is at its peak. Gruse, which are approximately the same size as the bluebacks, are among the chinooks and run at the same time, and it has seemed likely that bluebacks might be mistaken for grilse or grilse for bluebacks. An analysis has been made in which the correlation was determined between the percentage of grilse in the total count of chinooks and the number of bluebacks for the 10 weeks of the blueback run—June 11 to August 13. The Pearsonian coefficient of correlation is —0.72. Using the standard procedure the probability of chance occurrence of a coefficient of correlation as high as this is only 0.03, so that the observed negative correlation between the percentage of grilse and the number of bluebacks can be accepted as significant. Furthermore, it seems likely that the relationship between these two variables is curvilinear rather than rectilinear, as assumed by the Pearsonian coefficient, and that a true measure of the correlation would be even higher than that calculated. Our measure is, therefore, conservative. It seems quite likely that this negative correlation can be ascribed to a tendency on the part of the observers to mistake grilse for bluebacks when the bluebacks are numerous. This raises the question as to what other errors there may be in the counts. It is certainly difficult to distinguish species under the conditions of counting unless there is a fairly weh 1 marked difference in size, shape, or markings, especially if light conditions are not favorable. Observers should not be blamed for making errors under these conditions, but, in view of the evidence of error in identification just given, it would seem proper to investigate carefully to see how extensive these errors may be. The importance of having properly trained and experienced observers is obvious.
Page 1 and 2:
UNITED STATES DEPARTMENT OF THE INT
Page 3 and 4:
UNITED STATES DEPARTMENT OP THE INT
Page 5 and 6:
ABSTRACT The results of an investig
Page 7 and 8:
2 FISHERY BULLETIN OF THE FISH AND
Page 9 and 10:
Page 11 and 12:
Page 13 and 14:
Page 15 and 16:
Page 17 and 18:
Page 19 and 20:
14 FISHEBY BULLETIN OF THE FISH AND
Page 21 and 22:
Page 23 and 24:
Page 25 and 26:
20 FISHERY BULLETIN OF THE FISH AKD
Page 27 and 28:
Fish and Wildlife Service, Fishery
Page 29 and 30:
Page 31 and 32:
Page 33 and 34:
Page 35 and 36:
Page 37 and 38:
Page 39 and 40:
32 FISHEKY BULLETIN OF THE FISH AND
Page 41 and 42:
FISHERY BULLETIN OF THE FISH AND WI
Page 43 and 44:
Page 45 and 46:
Page 47 and 48:
Page 49 and 50:
Page 51 and 52:
Page 53 and 54:
Page 55 and 56:
Page 57 and 58:
Page 59 and 60:
Page 61 and 62:
Page 63 and 64:
Page 65 and 66:
Page 67 and 68:
Page 69 and 70:
Page 71 and 72: 64 FISHERY BULLETIN OF THE FISH AND
Page 75 and 76: 68 Centime tf гз 28 3l ,.-.-- 32
Page 79 and 80: 72 TABLE 18.- FISHERY BULLETIN OF T
Page 85 and 86: Blank page retained for pagination
Page 87 and 88: ABSTRACT Plankton collections made
Page 93 and 94: 84 FISHERY BULLETIN OP THE FISH AND
Page 101 and 102: 92 FISHERY BTTLLETIN OF THE FISH AN
Page 107 and 108: 98 FIBHEBY BULLETIN OP THE FISH AND
Page 109 and 110: 100 FISHERY BULLETIN OF THE FISH AN
Page 111 and 112: 102 FISHERY BULLETIN OP THE FISH AN
Page 113 and 114: ABSTRACT T7XCEPTIONAL DATA are avai
Page 121: 110 FISHEBY BULLETIN OF THE FISH AN
Page 125 and 126: 114 FISHERY. BULLETIN OF THE FISH A
Page 129 and 130: 118 FISHEBY BULLETIN OP THE FISH AN
Page 131 and 132: 120 FISHEHY BULLETIN OF THE FISH AN
Page 139 and 140: 128 FISHEEY BULLETIN OF THE FISH AN
Page 147 and 148: 136 FISHEKY BULLETIN OP THE FISH AN
Page 159 and 160: Blank page retained for pagination
Page 161 and 162: ABSTRACT This portion of a comprehe
Page 165 and 166: 152 FISHERY BULLETIN JOF THE FISH A
Page 173 and 174:
160 FISHEBY BULLETIN OF THE FISH AN
Page 175 and 176:
162 FISHERY BULLETIN OP THE FISH AN
Page 177 and 178:
Page 179 and 180:
166 FISHERY BULLETIN OF THE FISH AN
Page 181 and 182:
168 FI8HEET BULLETIN OF THE FISH AN
Page 183 and 184:
Page 185 and 186:
Page 187 and 188:
Page 189 and 190:
Page 191 and 192:
178 FISHERY BULLETIN OP THE PISH AN
Page 193 and 194:
Page 195 and 196:
Page 197 and 198:
Page 199 and 200:
Page 201 and 202:
188 FISHERY BULLETIN OP THE PISH AN
Page 203 and 204:
Page 205 and 206:
Page 207 and 208:
Page 209 and 210:
Page 211 and 212:
Page 213 and 214:
200 FISHEBY BULLETIN OP THE FISH AN
Page 215 and 216:
Page 217 and 218:
Page 219 and 220:
206 FISHEET BULLETIN OP THE FISH AN
Page 221 and 222:
Page 223 and 224:
210 FISHERY BULLETIN OF THE PISH AN
Page 225 and 226:
Page 227 and 228:
Page 229 and 230:
Page 231 and 232:
218 FISHEKY BULLETIN OF THE FISH AN
Page 233 and 234:
Page 235 and 236:
Page 237 and 238:
Page 239 and 240:
Page 241 and 242:
Page 243 and 244:
Page 245 and 246:
Page 247 and 248:
Page 249 and 250:
Page 251 and 252:
Page 253 and 254:
FLUCTUATIONS IN ABUNDANCE OF RED SA
Page 255 and 256:
FISHERY BULLETIN OP THE CTBH AND WI
Page 257 and 258:
Page 259 and 260:
Page 261 and 262:
Page 263 and 264:
FISHEKY BULLETIN OP THE FISH AND WI
Page 265 and 266:
Page 267 and 268:
Page 269 and 270:
Page 271 and 272:
Page 273 and 274:
Page 275 and 276:
Page 277 and 278:
FISHEBY BULLETIN OF THE FISH AND WI
Page 279 and 280:
FISHEltY BULLETIN OF THE FISH AND W
Page 281 and 282:
Cold Creek« Spring Creek Moraine C
Page 283 and 284:
Page 285 and 286:
Page 287 and 288:
FISHERY BULLETIN OP THE FISH AND WI
Page 289 and 290:
Page 291 and 292:
Page 293 and 294:
Page 295 and 296:
Page 297 and 298:
Page 299 and 300:
Page 301 and 302:
1 2 3 4 . 1 2 3 4 Age of seaward mi
Page 303 and 304:
Page 305 and 306:
Page 307 and 308:
Page 309 and 310:
Page 311 and 312:
Page 313 and 314:
Page 315 and 316:
THE WHITEFISH FISHERY OF LAKES HURO
Page 317 and 318:
WHITEFISH FISHERY OF LAKES HURON AN
Page 319 and 320:
Page 321 and 322:
WHITEPISH FISHERY OF LAKES HURON AN
Page 323 and 324:
Page 325 and 326:
Page 327 and 328:
Page 329 and 330:
PART II FLUCTUATIONS IN THE PRODUCT
Page 331 and 332:
Page 333 and 334:
WHITEFISH FISHERY OF LAKES HUKON AN
Page 335 and 336:
Page 337 and 338:
Page 339 and 340:
Page 341 and 342:
Page 343 and 344:
Page 345 and 346:
Page 347 and 348:
Page 349 and 350:
Page 351 and 352:
Page 353 and 354:
Page 355 and 356:
Page 357 and 358:
Page 359 and 360:
Page 361 and 362:
. * - гоо WHITEFISH FISHERY OF L
Page 363 and 364:
Page 365 and 366:
Page 367 and 368:
Page 369 and 370:
WHITEFI8H>FISHEBY OF LAKES HURON AN
Page 371 and 372:
WHITEFISH FISHERY OF LAKES HUEON AN
Page 373 and 374:
Page 375 and 376:
Page 377 and 378:
Page 379 and 380:
Page 381 and 382:
Page 383 and 384:
PART IV OBSERVATIONS ON THE FISHING
Page 385 and 386:
WHITEÏ4SH FISHERY OF- LAKES HURON
Page 387 and 388:
Page 389 and 390:
Page 391 and 392:
Page 393 and 394:
Page 395 and 396:
Page 397 and 398:
Page 399 and 400:
WHITEFISH FISHERY OF LAKES HUBON AN
Page 401 and 402:
TVHITEFISH FISHERY OF LAKES HURON A
Page 403 and 404:
Page 405 and 406:
Page 407 and 408:
Page 409 and 410:
Page 411 and 412:
WHITEPISH FISHERY OF LAKES HURON AN
show all

Fishery bulletin of the Fish and Wildlife Service - NOAA

Create successful ePaper yourself

Delete template?

Save as template?