Juvenile Salmon Survival in the Saint John River System

The Huntsman Marine LaboratOrY

W. D. Watt and G. H. Penney

Freshwater and An ad romous Division Resource Branch Department of Rsheries and Oceans Halifax, Nova Scotia

May , 1980

Canadian Technical Report of Fisheries and Aquatic Sciences No. 939 Canadian Technical Report of Fisheries and Aquatic Sciences The e report contain cientific and technical information that represent an important contribution to exi ting knowledge but which for orne rea on may not be appropriate for primary cientific (i.e. Journal) publication. Technical Reports are directed primarily towards a worldwide audience and have an international distribution. o restriction i pLaced on ubject matter and the eries reflect the broad intere t and policie of the Department of Fi herie and Ocean , namely. fi heries management technology and de elopment, ocean cience , and aquatic en ironments rele ant to Canada. Technical Report rna be cited a full publication . The correct citation appear abo e the ab tract of each report. Each report will be ab tracted in Aquatic Sciences and Fisherie Ab tracts and will be indexed annuall in the Department index to cientific and technical publication . umber 1456 in thi erie were i ued a Technical Reports of the Fi heries Re earch Board of Canada. umber 457-714 were i ued a Department of the En ironment. Fi herie and Marine ervice, Re earch and De elopment Directorate Technical Report . umber 715-924 were i ued a Department of Fi herie and the En ironment Fi herie and Marine Ser i e Te hni al Report . The urrent erie name wa changed with report number 925. Detail on the a ailabilit of Technical Report in hard copy may be obtained from the i uing e tabli hment indicated on the front co er.

Rapport technique canadien des sciences halieutiques et aquatiques Ce rapport contiennent de ren eignement cientifique et technique qui con tituent une contribution importante au connai ance actuelle mai qui, pour une raison ou pour une autre ne emblent pa approprie pour Ia publication dan un journal cientifique. II n' a aucune re triction quant au ujet, de fait, Ia erie reflete Ia a te gamme de interet et de politique du Mini tere de Peche et de Oceans notamment ge tion de peche ' technique et developpement, cience oceanique et en ironnement aquatique au Canada. Le Rapport technique peu ent etre con idere comme de publications complete . Le titre exact paraitra au haut du re ume de chaque rapport, qui era pub lie dan Ia re ue Aquatic Science and Fi herie Ab tract et qui figurera dan l'index annuel de publication cientifique et technique du Mini tere. Les numero 1-456 de cette erie ont ete publies a titre de Rapport technique de I'Office de recherche ur le pecherie du Canada. Le numero 457-714, a titre de Rapport technique ~e Ia Direction generate de Ia recherche et du developpement ervice de peche et de la mer mini tere de I'En ironnement. Le numero 715-924 ont ete publie a titre de Rapport technique du ervice de peche et de Ia mer, Mini tere de Peche et de l'Environnement. Le nom de Ia erie a ete modifie a partir du numero 925. La page couverture porte le nom de l'etabli ement auteur ou l'on peut e procurer le rapport ou cou erture cartonnee. Canadian Technical Report of Fisheries and Aquatic Sciences No. 939

May, 1980

JUVENILE SALMON SURVIVAL IN THE SAINT JOHN RIVER SYSTEM

W.D. Watt and G.H. Penney

Freshwater and Anadromous sion Resource Branch Department of Fisheries and Oceans Halifax, Nova Scotia B3J 2S7 ~ Minister of Supply and Services Canada 1980 Cat. No. Fs 97-6/1980-0939 ISSN 0706-6457 iii

CONTENTS

LIST OF TABLES ..... v LIST O.F' ILLUSTRATIONS . v

~ -" ABSTRACT/RESUME . i

INTRODUCTION. . 1 METHODS AND RESULTS .

DISCUSSION. 4

CONCLUSIONS 5

REFERENCES. . 13

LIST OF TABLES

TABLE 1. Numbers of wild salmon counted at the Mac facilities during the estimated (from scale ) composition of the various ups ...... 2

TABLE 2. Nrunbers of salmon and lse in spawning escapements above Mactaquac Dam during 1967-77 and es egg depositions ( per 1 0 0 m2 ) • • • • • 2

TABLE 3. Actual returns to Mactaquac wild virgin salmon progeny from spawning years 1967-72 ...... 2

TABLE 4. Total potential returns to Mactaquac for spawning years 1967-72 ...... 3

TABLE 5. Tob salmon spawning escapement and estimated egg deposition ...... 4

LIST OF ILLUSTRATIONS

FIG. l. Saint John River system map, indicating positions of dams and some major tributaries ...... vi

FIG. 2. Total ac returns to of wild vi n salmon and from spawning years 1967-72 vs. den above Mac 7

FIG. 3. Es re ve dis (%) of wild salmon grilse returns among the harvesters, actual returns counted at 8

FIG. 4. Total po al returns to of wild virgin salmon and lse from spawning years 1967-72 vs. egg-deposition density above Mactaquac . 9

FIG. 5. Actual and returns to Mactaquac per 8,000 eggs (one salmon) of wild virgin salmon and gr se progeny from spawning years 1967-72 ...... 10 FIG. 6 . 1 returns to Mac of wild virg sa and grilse years 1967-72 vs. est densi 11 vii

ABS'I'HAC'l'

tt, W.D. and G.H. Penney. 1980. Juvenile salmon survival in the Saint John River system. Can. Tech. Rep. Fish. Aquat. Sci. No. 939. vii + 13 p.

For the Saint John Hivc~r system above Mactaquac Dam the number of actual v1n;in returns per female salmon spawner rose from 10 ( 8, 000 eggs) for SjXHvn year 1967 to a peak of 16 for 1969 and then to 3 for 1972. Most returns were in the fourth, ifth and sixth This and decline is attributed t:o a combination o poor juvenile survival (ciue to ) in the main stem of the Saint John River and to changes the proportions of spawning adults released into the main stem and into the Tobique River (a tributary). The adult· return for salmon spawners in 'l'obique River was high ( 16.8 per 8, 000 eggs), for fish released into the main stem (Woodstock) and not migrating to the 'l'obique, the return rate was not significantly greater than zero (2.8 per 8,000 eggs) To maximize the number of wild salmon returns, it is recommended that t.he rst priority should be to ensure an adequate egg-deposition density in Tobique River.

Key words: Atlantic salmon, Saint John River syst.em, Mactaquac Dam, Tobique Hiver, juvenile salmon survival, rearing habitat, egg-deposition density, water _quality.

RESUME

'datt, W.D. and G.H. Penney. 1980. Juvenile salmon survival in the Saint ,John River system. Can. Tech. Rep. Fish. Aquat. Sci. No. 939. vii + 13 p.

Pour le system fluviale de la riviere Saint-Jean en amont du barrage de Hactaquac le nombre de saumon reproducteurs vierges, issue de chaque femelle en fraye, s'est accru a de 10 (pour 8,000 oeufs) en 1967 jusqu'a atteindre un sommet de 16 en 969 et decliner j 3 en 1972. La pluspart des saumons reproducteurs qui retournerent a frayere d'origine au cours de ces annees de reproduction etaient ages de quatre, ou six ans. Cet accroissement et le declin suivit sont attri- a l'effet combine d'une mauvaisf~ survie ( cause de la pollution) des saumoneaux dans le tronc principale de la riviere Saint-,Jean et aux changements dans les relatives des saumons reproducteurs liberes dans le tronc de la riviere Saint-Jean et dans la riviere 'I'obique ( tributaire de La moyenne des issue des saumon de la riviere pour 8,000 oeufs), que pour les saumons dans le tronc principale (Woodstock) et qui n'emigrerent pas dans riviere 'l'obique, le taux de retour ne fut pas significativement plus grand que zero (2.8 pour 8,000 oeufs). La "maximisation" du nombre de saumon reproducteurs natifs que l'on donne priorite a la ition d'oeu£ en densite suffisante dans la riviere Tobique. N 1

Dam

Beechwood Dam NEW BRUNSWICK

MAINE

Mactaquac

FIG. l. s John River system map, indicating positions of dams and some major tributaries. l NTHOIJlll "['I ON M1':'1'l!O!JS /\NU HESULTS

of the Upstream migrating anadromous f sh sorted (species) in the fish all an~:1drornous at Mactaquac Dam, and John River (past then all Atlantic salmon are carried counted and sorted at the Mactaquac fish tank truck to the salmon-sorting facil ty handll facility, and from here they have at Mactaquac Hatchery. been rried in tank trucks to various lease points. Atlantic salmon and continuing to most part, trucked either to and life history of at Woodstock or to the lse returning to tributary (Fig. l) . Mactaquac have determined readings of scale samples ('l'able l) . Data S lmon leased at Woodstock have a from returns of hatchery releases were not choi of spawning sites they may remain used in this analys The wild- in the main stem, enter the Becaguimec indicate that uvenile salmon in the Saint River some other small tributary, or John River smoltified after 2 (49.1%), pass over the fish lift at Beechwood Darn. 3 (49.3%) or 4 (1.6%) fresh water. Above Beechv10od they may remain in the The adults returned a one year at sea main stem between Beechwood and Grand Falls, as grilse (39.2%), or after two sea-year·s pass to Salmon River or some other small (51.4%) or three sea-years ( .2%) as tributary, or pass up through the fish virgin salmon. Also, on average, about ladder at Tobique Narrows Darn on the 9.2% of the total were repeat spawners rrob H1 ver ~ (non-virgin salmon) .

areas o access1ble juvenile sal Most virgin returns (98.2%) were in mon rearing habitat available above the life-history categories 2:1 (i.e., 2- Mactaquac Dam are distributed as follows: year-old smolt~ and one at sea, 8.9%), 3 : l ( 2 3 . 6% ) , 2 : 2 ( 3 0 . 1% and 3 : 2 ( 2 5 . 6% ) . Thus, most returns come in the fourth, fifth and i::stimat

depositions in the Sain John River Mactaquac Dam for the 1967-77 have been estimat.ed (Table 41,810 24.1 ratios for estimation of tential deposition were taken as overa Beechwocx:1 Darn to from a data series (1967-77) of vi Grand Falls 25,080 14.5 sexing of the data 94,440 54.5

Other accessible 11,950 6.9

'I'otal 173,280 100.0 qrilse. For was assumed 8,000 eggs/fish (1,80 grilse produce 3,200 Of the accessible (from Woodstock) apparent (Table 2) that gr tributaries other than the Tobique, the ponent, because of the small fish size and best for salmon are the Salmon low proportion of females, and which are es ted relative insignificant 5, 100 and 4, 0 eggs to total juvenile Atlantic sal spawning. mon rearing habitat. A number of other small tributaries contain minor quantities The fish-return data (Table ) can be of rearing habitat (approximately 2,650 used to as the various life-history units in all). classes to spawning year. This arrangement (Table 3) allows comparison of Atlantic salmon management policy on the total annual returns to of the Saint John River has attempted to maxi mize salmon production by aiming for a potential egg deposition in all accessible tion densities for the river system habitat of 240 eqgs/100 m2 as recolnJ11ended by (Fi . 2) . 'l'he shape of Elson ( 1957) suggests a curved line, which could be lower 1 The history of hydroelectric develop- sur·vi val at on the Saint John River and the inter sity of 1972. However, ac~ s of these developments with aquatic density is ecology and fisheries have been described (1957) recommended s/ by Ruggles and Watt (1975). 100m2 • When a least squares straight "', Nwnl.Jer:~ of wild qr.ilse and sal_mon counted at the Mactaquac fish-passaqe fac;i1ities rs 1972 78 a11d estimated (from scale readings) composition of the various age groups.

TABLE 2. Nwnbers of salmon and gri1se in spawning escapements above Mactaquac Dam during 19 7- 7 estimat.ed egg depositrons (per 100 m2 ). (The numbers have been corrected for the reported angling catch. The juvenile habitat accessible above Mactaquac is taken as 17,328,000 m2 .}

------~ 'l'ot,al Year eggs/100 m" ------196 7 487 18.6 682 0. 9 19.5 1968 12 3 4. 7 954 1.3 . 0 1969 640 24.5 1,885 2. 6 2 7. l 970 1,219 46.7 2,445 3. 0.0 1971 1,383 52.9 1,425 . 9 . 8 19 2 16 177.2 7 • 0 178. 1973 2,305 88.2 2,978 4 .l 92. 19 74 5, 0 J 19 3. 0 6,142 8.4 20 1975 7, 271 278.3 9,629 3.2 :!9 . 5 l 6 6,003 229.8 12,578 17.2 47.0 l 77 7,562 289.4 7,339 10.0 299.

TABLE 3. Actual returns to Mactaquac of wild virgin salmon progeny from spawning years 1967-72.

Spawning Total year 2:1-- actual return

1967 688i 596 37 1,260 1,551 0 0 '132 1968 110 404 34 549 377 35 0 1,509 1969 1,413 1,762 57 3,806 2,208 31 84 9,361 1970 1,593 3,727 177 3,566 2,999 0 37 1,209 1971 1,941 2,658 39 2, llO 1,858 0 67 8' 6 73 1972 3,962 2,545 33 4,236 1,817 15:1 571 12,665

~Number estimated from average proport.ion. l '-S fitted to these data (Y'''S, 340 + rection values (above) for each return 49. Sx), theY- intercept is not signi- year to the actual return data (Table 3) f cantly .05) greater than 0, as it A plot of these total potential returns shoul be f the relationship were for each spawning year versus the esti s1gnificantly curved. Also, when fitted mated egg-deposition with a second-order polynomial, the curved curve (Fig. 4) which inc is not a significantly better fit appearance to the than the straiqhi line; hence it must be actual returns ( concluded that-the apparent reduction in a diminished rate survival of the 1 72 eq9s is not signifi returns in the year 1972 is cant. (Fig. 4). Hmvever, as was shown with the curve for actual returns (Fig. 2) , the 'l'he returns presented (Tables J and 3) apparent reduction survival s not are o fish that have escaped capture by statistically significant. commercial fishennen (i.e., incidental catches, since the commercial salmon It is common to consider changes in f1shery has been closed since 1972) , survival rates in terms of returns per poachers, the Indian food fishery at spawning female. A female salmon lays Kingsclear and anglers. Estimates of approximately 8,000 eggs (3,200 for a the relative (percent) impact on wild female grilse). Accordingly, the return returns by the various rates (actual and potential) per 8,000 in the harvesting are eggs deposited above Mactaquac Dam are (Fig. 3) . The values for angling depicted (Fig. 5). 'rhis histogram indi-- catches have been derived from reported cates that survival between catches (New Brunswick Fish and Wildlife 1967 and 1969 and then during Branch); catches in the Indian food fishery 1970-72. have been estimated from observations; and the combined levels of poaching and It was initially considered that this incidental catches in commercial gear set trend probably represented mortality for other species have been roughly esti problem in downstream fish due to mated at about 10% for the years 1972-75 changes in turbine and 20% for the years 1976-78. However, an hydropower generation and development Since the closure of the commercial yields nothing that could account for the salmon fishery in 1972, the proportion of trend. Possible changes in smo1t predation the salmon run reaching the Mactaquac fish rates (eg , by chain pickerel) have lso handling facilities has steadily declined been considered and discounted. The as a result of increased harvesting by the known factor that to parallel Indian food fishery, and incidental com survival-rate the proportion of mercial catches and poaching. The propor the egg deposition in the •rob Ri. ve tion of the salmon run taken by anglers (dashed line in l"i.g. 5). The variation in has remained fairly constant. The grilse returns per 8,000 would be largely returns show a similar exploitation trend, accounted for if uvenile salmon with the exception that the proportion survival ) were substan taken by the Indian food fishery is lower better for spawned in Tob than for salmon. than for fish spawned elsewhere Saint John River system. Total potential returns (Table 4) were computed by applying the approximate cor- To test this hypothesis urther,

TABLE 4. returns to Mactaquac for 19 7-72. ac 1 returns plus e of the numbers of fish taken fishermen, poachers, the Indian food fishery and anglers) .

Potential returns Spawning 'I'otal year potential return

1967 8001. 6 89 43 1 '4 36 1,843 0 0 4' 811 1968 128 469 41 652 4 82 4 0 J.,816 1969 l' 6 37 2,141 67 4, 871 2,794 65 174 1,749 1970 1,935 4' 38 3 245 4,515 6, 2 31 0 74 7 f 3 8 3 1971 2,275 3,680 58 4,375 3,737 0 190 4,315 19 72 5,487 3,857 57 8,521 5,143 421. 1581. 23,265 ------'·Number estimated from average proportion. t

H turns to

Dep:Jsihon Year of egg;/100 m2

379 13.5 78 352 6. DISCUSSION 1969 593 ,572 45.6 1970 932 1,850 70.1 1971 1,166 738 83.7 1972 2,140 150.9 197 3 88.8 3, 728 257.8 1975 6, 722 369. 1976 7 ,~..L:JO"C 1977 ,305 325.

system usive o not is- tical regressions on egg deposition in river sec- tions from Woodstock to Beechwood and from Beechwood to Grand Falls are also not significant.

To estimate urviva from spawners in River and those in the int John main tributaries (above of simultaneous John Fiver, where water quality Wi:lS suit tion densities, the lope will inevitably able for spawning activities in October flatten out. Elson (1957) suggested 240 November but unsuitable for juvenile eggs/100 m2 as near optimal for Maritimes salmon survival during the mid-summer salmon rivers. Elson (1975) has revised low-flow periods (Environment Canada 1973). the figure downward to about 170/100 m2 • Moreover, water toxicity have been Symons (1979) considers that the relation- reported by MacDonald et (1970) and ship between smolt and Dominy (1973) in main stem Saint John River deposition density vary lvater at the Mactaquac salmon hatchery age at smoltifi.cation. Thus a river (usually during high spring flows). producing smol ts would require a lower ity for maximum Fish spawning in the smaller tribu smolt production would one producing taries (Salmon, Becaguimec, etc.) would 3-year-old or 4-year-old smolts. On this encounter suitable water quality, and these basis, a river such as the Saint John tributaries should be capable of providing (Tobique) which produces roughly half and at least a small proportion of the wild half 2- and 3-year-old smolts can be salmon run. Unfortunately, it is impos- expected to approach maximum smolt pro- sible at to sort the adult fish duction at a density 150-200 according to ir tributary of origin. eggs/100m2 • Tobique River may Inevitably, fish from other tributaries already have reached its maximum were released in Tobique River and most of tion in 1972 at an egg density the fish released at Woodstock were Tobique 100m2 • River fish, and thus less inclined to spawn in any of the other tributaries. In any case, egg densities consider ably in excess of this theoretical Even so, some spawning must have taken (Table 5) occurred in Tobique River place at least in the Becaguimec River, 1975-77. Returns from these whose confluence is near the Woodstock years (expected in 1981-83) release site. Electrofishing results a fitted curve which calibrates (available since 1972) do indicate reason Tobique River for optimum smolt production. ably high juvenile populations in this tributary (Francis 1980). However, the entire juvenile-salmon rearing area avail CONCLUSIONS able in the Becaguimec River is equivalent to only about 41 of the rearing area in the Tobique River. Hence even if this 1. The adult-return potential of fish tributary was producing to capacity, its released in or success contribution could not significantly into the Tobique River is alter the trends (Figs. 5 and 6). (averaging 16.8 ± 1.0 returns per female salmon) . The smolts from the Tobique River tributary have to pass through three 2. The adult-return potential for fish headponds (possible predation) and over released at Woodstock and not migrat three power dams (possible spillway and ing into the Tobique River is low turbine mortality) in their seaward migra ( 2. 8 ± l. 8 ret.urns per female) . tion. The possibility of increased down stream fish-passage mortali was initially 3. To maximize the number of wild advanced to explain the off in return mon returns to Mactaquac, the t rates to t-lactaquac (Fig. 5). However, the priority should be to high return rate for fish spawned egg-depos River ( as in the River virtually rules out 6 any unusually high rates of downstream 0 eggs or about mortality. salmon spawners).

In spawning years 1971 and 1972, 4. The rise and decline in salmon ret. urn small numbers of hatchery-reared returns rates to Mactaquac for spawning were included among the potential spawners 1967-72 is attributed to released at Woodstock and Tobique. There of poor juvenile survival (due to is evidence (unpublished) that the migra pollution) in the main stem of the tory behaviour of these hatchery fish is Saint John River and changes in the rather different from that of wild fish, relative of returning and thus there is some question as to adults the main stem their comparability in terms of potential and into Tobique Hiver. deposition. The numbers involved were % of salmon in 1971 and ll% in 1972, and 5. The evidence suggests that the inclusions might have caused slightly Saint John River reduced survivals in these years. The tality during the migra- tion is not unusually high. effect, if present, does not appear to be statistically significant.

The data points in Fig. 6 suggest that the relationship between deposition in the Tobique River and returns to may actually be curved, but is not significant (p>O.OS). However, at higher egg-deposi-

--·1972 12 01970 ...... (I') '0 c: (1:1 (I') :J 0 10 .c ...... o1969 -(I') ...c: Cl 1971 :J 8 -G)...

(1:1 :J 0 -(1:1 6 ....(1:1 0 1-

2 01968

0~------~------~------~------~--~------~ 0 100 150 Eggs r 100m2 above Mactaquac

FIG. 2. Total actual returns to Mactaquac of ld virgin salmon and grilse from spawning years 1967-·72 vs. e sit dens above Mactaquac. 8

Angling

In dian food c fishery 0 E ccs (/) Incidental catch and -0 poaching -I-'c (J) (.) Actual I.- (J) returns to a.. Mactaquac

Angling Indian food fishery

catch and poaching

Actual returns to Mac taq uac

0~~---L~----L------L------L------L~~~ 1972 1973 1974 1975 19 76 1977 i 978 n a

FIG. 3. Es salmon and grilse returns and actual returns 25

e1972

-Cl) "C c 20 C'O Cl) :s 1970 0 .r::.- • -(/) c 15 ... • 1971 :s -(I)... 1969 C'O • c 10 -(I) 0 a.-

5 e1967

e1968

QL-----·------~------~------~------~ 0 50 100 150 200 Eggs r 100m2 above Mactaquac

FIG. 4. Tota 1 returns to Mactaquac of wild virgin salmon and grilse from spawning years 1967-72 vs. egg-deposit.ion density above Nactaquac 10

Correction for , Indian fishery, poaching and incidental catches

return rate 100 0--0 Tobiqlle River 0 I \ I I ' \ \ I \ I \ I \ 0 I \ _," I I ,; I \ ,; 20 I \ I 8 !... I .. I \ "' "' I 0 I ~ I I I \ 0:: I I I \ (j) I \ ::::J I I 0' I \ I \ :0 (j) I \ 01 I \ P2 I \ 01 I I c 15 I 60 Q) \ I v I Q) I ~ 0 \ (j) I 0 \ 0 0 I I Q I \ (j) co I 0 I v !... (f) (]) OJ 01 0.10 40 (]) (j) 0 c 0 !... ::::J +-' Q) rr

5 2

oL-~-L~~~~~--~~~--~~~~o 1967 1968 1969 1970 1971 1972 Spawning year

FIG. 5. Actual and potential returns to Mactaquac per 8,000 eggs (one female salmon) of wild virgin salmon and grilse progeny from spawning years 1967-72. 25

• 1972 -(/) "'0 c::: Cl'l (/) :I 0 20 -.s:::. () • 19 70 Cl'l :I 0" Cl'l 15 v • 1971 -Cl'l ~ 0 -(/) c::: 10 :I'"' <1> -"'" Cl'l c::: -<1> 5 ..... 0 a.

e1968

0 0 50 100 150 200 gsper100 in Tobique River

FIG. 6. Total returns to Mactaquac of wild virgin salmon and se spawning years 1967-72 vs. es egg-deposition density the Tobique River.

FEFERENCES Hatt, W.D., G.ll. Hardinq, ,J. Caldwell and A. McMinn. 1973. Sludqeworms Dominy, C.L. 1973. Hecent changes in (Oligochaetes) as indicators of water Atlantic salmon (Sa~lmo sa.lar) runs in pollution in the Saint John River. the Light of environmental changes in Report #15c from the Saint John River the Saint John Hiver, New Brunswick, Basin Board, Fredericton, N.B. 31 p. Canada. Biol. Conserv. 5:105-113.

Elson, P.F. 1957. Number of salmon needed to maintain stocks. Can. Fish. Cult. 21:7-17.

Elson, P.F. 1975. Atlantic salmon rivers, smolt production und optimal spawninq: an overview of natural production. Lllt. At . Salmon Found. Spec. Pub]. Ser. 6:96-119.

Environment Canada. 1973. Water quality data report submitted to the Saint John Hiver Basin Board. Prepared by the Water Quality Division, Inland Waters Branch, Ottawa. 473 p.

Francis, A.A. 1980. Densities of juvenile Atlantic salmon and other species, and related data from electroseining studies in the Saint John River system, 1968-78. Freshwater and Anadromous Division, Dept. of Fisheries and Oceans, Halifax, Nova Scotia. Can. Data. Rep. Fish. Aquat. Sci. No. 178. 102 p.

Keachie, P.M. and R.P. C6t~. 1973. Toxic pollutants in the Saint John River Basin. Report #16 from the Saint John River Basin Board, Fredericton, N.B. 179 p.

MacDonald, J .R., R.A. Row and J .R. Machell. 1970. Pollution survey Saint John River syste111, 1969. Unpublished report from the Resource Development Branch, Depart ment of Fisheries and Forestry, Halifax, N.S. 103 p.

Rugqles, C.P. and W.D. Watt. 1975. Ecologi cal changes due to hydroelectric develop ment on the Saint John River. J. Fish. Res. Bd. Canada 32:161-170.

Saunders, D.E. 1969. Water quality studies in the Mactaquac impoundment. Unpub lished thesis, Department of Civil Enqineerinq, University of New Brunswick, Fredericton, N.B. 69 p.

Sprague, J.B. 1964. Chemical surveys of the Saint John River, tributaries, impoundments, and estuary in 1959 and 1960. Fisheries Research Board of Canada, Manuscript Report Series (O&L) No. 181. 59 p.

Symons, P.E.K. 1979. Estimated escapement of Atlantic salmon (Salmo salar) for maximum smolt production in rivers of different productivity. J. Fish. Res. Bd. Canada 36:132-140.

Watt, W.D., 1973. Aquatic ecoloqy of the Saint John River - Volume l. Report #l5f from the Saint John River Basin Board, Fredericton, N.B. 112 p.