BU1DGICM. Sr"Tl0".

This aeri.. Includes unp~ilIIIIflllII\lland data recorda not In_ lor ..- _Han.They should not be reform to In publl=tlons with­out c1ecm:mce from the luulnq Board estobllahment andwithout clear lndication of their manu.crtpt PrtwJ.

FISHEBIES BESEABCH .OABDOF CANADA

MANUSCRIPT REPORT SERIES

No.1176

Lobster (Homarus americanus)Production in British Columbia

byR. J. Ghelardi and C. T. Shoop

Pacific Biological Station, Nanaimo, B.C.

April 1972

Thlo _.. Includes _ubll8hed _llmlnary _

cmd data ..corda not Intonclod for ...-aI dlntbutlon.They ohou1cl nol be ref...-d 10 In pubIk:atIooa wtth­out clemance from the 1asu1nq Board eetabUahment andwithout clear indiootlon 01 their manUKT1pt .tatua.

FISHERIES RESEAR£H BOARDOF £ANADA

MANUSCRIPT REPORT SERIES

No. 1176

Lobster (Homarus americanus)Production in British Columbia

byR. J. Ghelardi and C. T. Shoop

Pacific Biological Station, Nanairno, B.C.

April 1972

Scale of the Transplant

TABLE OF CONTENTS

FOREWORD •••••• ·.••·••• .. ••·••• .. ••· .. •·••·•··• .. •••·•• .. •• .... • .. ••• •

ACKNOWLEDGHEtlrS ..

ItrrRODUCfION .

BIOLOGY OF LOBSTERS AND HABITAT CIlARACfERISTICSOF THE EAST COAST LOBSTER FISHERY ..

1. Reaume of Ufe History and Basic Habitat Requirements .

2. Population Density and Conservation ······

REQUIREHEtlrS FOR ESTABLISHMENT OF A PACIFIC LOBSTER FISHERY ••••••••••

1. Key Factors .

2. Pacific Lobster Ufe History ·•·············

3. Suitability of Pacific Habitat .

CONCEPT OF A TRANSPLANT .

1. Methods and Phi losophy .

2. Practical Sites for the Introduction and Establishmentof Lobsters on the British Columbia Coast .

(8) Discussion of Two Specific Localities as Type Examples .

-- Hecate Strait .-- Baynes Sound .

3.

4. Decisions and Economics .

SUMMARy • .. • ••• .. •• .. • .. • .. • • .. •• .. •••• ..

Page

9

910

10

12

12

REFERENCES

APPENDIX I

APPENDIX II

...........................................................

..........................................................

..........................................................

13

15-25

27-31

- 2 -

FOREWORD

A ccmnerc1al lobster population is feasible at selected sites

on the Canadian Pacific coast.

Experiments in pens, hatchery, and restricted sea basins

demonstrated that Atlantic lobsters survived, grew, and reproduced in

these waters, but failed to establish a brood stock principally because

seedings were too small and larvae were dispersed by flushing. Further

such research is not likely to produce a viable population.

The prime requirement for success is the establishment of an

adequate brood stock in an area where the resulting larvae will be

conserved and recruited to the parent stock.

An experiment is discussed that takes this factor into account.

- 3 -

ACKNOWLEDGMENTS

Hany of the ideas and words in this paper originated with

Dr. John P. Tully. Only the mistakes are uniquely our own. Hr. Jergen

Westrhe1m and Mr. Prank Nash supplied many corrections and criticisms

which eliminated some, at least, of the latter.

- 4 -

INTROOUCTION

Individual lobsters can perform all of their basic Hfe functions inthe Pacific just as they do in the Atlantic. Ten Canadian experiments haveshown that adult lobsters can be obtained and quarantined (to reduce thepossibility of importing pest parasites), shipped and successfully introduced,in prime condition, into the Pacific; that they survive and find food adequatefor growth at rates and in increments equal to those observed in the Atlantic,develop sperm and ova, and mate, both in the wild and in pens, and produceembryos which hatch successfully; that 8 large number of larvae can be hatchedand raised in a hatchery, and juveniles (Stage 4+1/2, 1, 2, and < 4 years)reared to sexual maturity (4+ years) in pens and cages in the Pacific (Fraser,1916; Adams, 1948; Faulkner, 1958; Appendix II: Fatty Basin Studies, 1966-71,data on file).

But none of these studies ever demonstrated a complete cycle ofpopulation reproduction in the Pacific, nor was any experiment really designedto do so (Ghelardi, 1967).

Plankton tOW's in Fatty Basin, Vancouver Island, B.C., showed thatnormal hatching of live, first stages from free females occurred for 3 years,yet no second, third or fourth stage larvae were ever found. All of the firststage larvae may have died before metamorphosis, but no difficulty wasexperienced in raising them through all stages in the hatchery. It is notablethat Fatty Basin as well as all of the other natural sites used for lobsterexperiments were subject to complete flushing during the 4 weeks of pelagiclarval life during Hay through August. Under such conditions, any larvaeproduced would be so widely dispersed that they would be difficult to find,let alone provide a benthic density sufficient to ensure that resulting adults

find one another to mate.

In order to provide normal opportunities for mating and compensatefor natural mortalities, a seeded brood stock must be initially establishedand maintained at a population density comparable to east coast lobster grounds.Natural recruitment of a second generation to the brood stock can occur only1£ larvae and the resulting juveniles and adults survive and are not dispersedfrom one another and the parent population by distances that are greater thantheir normal migration pattern. This means that the oceanographiccharacteristics of the experimental site must be conservative.

These considerations indicate that the feasibility of establishing aprofitable lobster fishery in British Columbia has never been criticallytested. We will now propose a new experiment that takes into account keyfactors not included in earlier designs.

Testing the idea that a viable lobster industry can be establishedon the west coast requires: (1) listing what is known about the biology oflobsters and habitat characteristics of the successful lobster fishery onthe east coast; (2) evidence that basic biological processes are similar inthe Pacific; (3) selection of a site where habitat requirements can besatisfied; (4) design of an experiment with a scale and criteria suitable forproducing reasonably accurate demographic information.

- 5 •

BIOLOGY OF LOBSTERS AND HABITATCHARACXERISTICS OF THE EAST COAST LOBSTER FISHERY

1. Resume of Life History and Basic Habitat Requirements

In the Atlantic, lobsters normally mate from early June to September.The females usually lay eggs every other year and eggs are carried attachedto swirmnerets under the abdomen until they hatch during the following mid-Juneto September period. The larvae are pelagic, floating mostly between thesurface and 3-ft depths during the day, although they may scatter deeper atnight. The pelagic period occurs during June to September, and lasts for aslittle as one or as much as two months, depending largely on temperature.They moult three times (larval stages 1, 2, 3, 4) before settling to thebottom midway between the 3rd and 4th moults (juvenile stage 4+1/2). Size andage at sexual maturity vary according to area and are determined mainly byhigher temperature which accelerates rate of development by reducing the timebetween moults.

It is not possible to accurately determine a lobster's age, but itmay be presumed that in areas with bottom temperature within the range 3-l4°Cthey can attain sexual maturity at total lengths of 7 or 8 inches, and weightsof about 0.5 Ib in no less than four but usually more years, after which thereproductive cycle is apparently repeated biennially. Hence camnercial sizeanimals (total length:> 7 1/4 inches) are a minimum of 4-5 years of age(PaloheimO, 1962; Rutherford, Wilder and Frick, 1967).

Successful benthic settlement of £!..!.!&!.£ larval stages requiressurface water temperatures within the range l4-20°C, salinity greater than 25%..,and conservation of water mass, during the period June through August.

Adult and 1uvenile lobsters need bottom temperatures of 0-14°C, rough(rock and sand) substrate, and depths of 25 fms or less.

2. Population Density and Conservation

The east coast lobster fishery has remained fairly stable at annuallandings of about 40 to 50 million lb per year since 1950, indicating thatannual recruitment and growth of legal lobsters exceeds natural mortalityby this amount.

Range and median population densities (legal-size lobsters) are:5,000-28,800 lb/sq nautical milel ; and 12,550 Ib/sq nautical mile1 (fran TableIII, Rutherford et a1. 1967). Thus, estimated minimum stock density is about10,000 legal-size individuals per sq mile. We will therefore assume that apopulation density less than this is insufficient to permit a frequency ofmating and population reproduction high enough to establish a fishery.

lHereafter all area measurements (sq miles) are to be interpreted assq nautical miles.

- 6 -

To maintain the level of recruitment observed on the east coast,animals must either be conserved within the area of the fishery during thepelagic larval period or, if widely dispersed, return as immigrant adults.Wilder (1953, 1960, 19638, h, 1965) has shown by tagging and marking studiesthat adult lobsters are not migratory and only move, on the average, less than2 miles-straight line distance from point of release-per year. Apparently,persistence of lobster populations on the east coast is due at least in part tothe presence of slow eddies that may move pelagic animals along the Atlanticcoast, yet conserve them within the grounds during the period mid-June toSeptember. The existence of large-scale conservative eddies on the east coastis confirmed hydrographically by current measurements; geologically, by the

formation of many banks (e.g., George's, Grand, etc.); and biologically, bypresence and persistence of many localized stocks of fish and shellfish inaddition to lobsters (crabs, oysters, clams, herring, cod) which also havepelagic stages which would be dissipated by non-conservative surface currentsif these were present.

REQUIRElIEtfrS FOR EsrABLISHKENr OF A PACIFIC IDBsrER PISHERY

1. Key Factors

Present evidence indicates that the key factors are: (1) adultdensity during snd after introduction must be great enough to ensure mating(Le., >' 10,000 sexually mature lobsters with 1:1 sex ratio per sq mile);(2) conservation of larvae; (3) growth and recruitment of adult lobstersexceeds total natural adult mortality (death + emigration) over the initial4-year introduction period (first mating of Fa)'

2. Pacific Lobster Life History

Observations on the 5,000 adults released in Fatty Basin confirms aPacific life history similar to that in the Atlantic with some exceptions.Hatching begins earlier in the Pacific since it started consistently during thelast week of May in 1969, 1970 and 1971. Mating appears to occur annuallyrather than biennially; warmer year-round bottom temperatures (range, 6-17°C)will likely result in faster growth rates and sexual maturity in 4 years or less.

3. Suitability of Pacific Habitat

Physical requirements can apparently be satisfied in various areasalong the Pacific Canadian coast. The existence of conservative conditions atappropriate periods is inferred physically from current measurements, conservedwarm water areas in northern Georgia Strait, and existence of banks (e.g.,Hecate Strait); biologically by populations of indigenous species such asflatfish and crabs, and successfully introduced animals such as Japanese oysters(Crassostrea.8..!.&!!) and Atlantic clams ~ arenaria) which have pelagic lifehistory phases and yet obtain. recruits from local brood stocks (Ketchen, 1956;Butler, 1961; Quayle, 1964). Satisfactory temperature and salinity ranges,bottom types and depths can be fulfilled at several Pacific sites as shown bypublished information from oceanographic studies (Ketchen, 1956; Pickard, 1961;1963; Hollister, 1964).

- 7-

Biological interactions affecting a lobster fishery have not beenexamined in detail. Harmful competitive effect of lobsters on a ccmnerciallyexploited native crab (Cancer magister) does not seem likely. ~coexists with two cancroid crabs (Cancer borealis, f.~) on the eastcoast that are simi.lar to species here. Habitats of f. magister (level sandand mud bottom) and lobsters (rough, rocky areas) are contiguous in FattyBasin but do not, in the main, appear to overlap. A dense aggregation ofmegalopa stage f. magister entered Fatty Basin in 1969 (Hardon, 1969) andestablished a population density 10 or more times greater than that observedbefore lobsters were introduced. The habitat of another Pacific crab, Cancerproductus, coincides with that of~, but observations to date have notrevealed any obvious interact ions between the two animals.

Other biological features such as availability of preferred food, theeffect of predation and competition, can only be assumed satisfactory at thistime on the basis of results from the work in Fatty Basin (growth and survivalof adults, embryos and first stage larvae over several years). Theseassumptions should be checked by further studies and monitoring during andafter efforts to establish a fishery.

OONCEPr OF A TRANSPUNT

1. Methods and Phi losophy

In earlier experiments, primary emphasis was placed on the retentionof adults either by natural barriers such as shallow sills or proposedconstruction of fences. This philosophy resulted from the apparent rapid lossof animals during several introductions (Fraser, 1916; Adams, 1946; Butler,1964a). It is our view that the failure of earlier experiments was mainly dueto other causes and that retention of adults by sills or fences is ofsecondary importance. Evidently there is a minimum size of area and grosspopulation required.

If the test site is large enough with respect to adult ambit, adultlobsters would be conserved within the release area and losses would resultfrom death rather than emigration. These losses can be ignored providing theinitial population is large enough to provide sufficient recruitment to offsetthem.

A colony of lobsters could be established in the Pacific either with~ shipped from the east,~ and 1uveniles hatched and reared inBritish Columbia or the east coast, or a combination of both. Feasibility ofattempting an introduction with adults was demonstrated by the Fatty Basin andearlier experiments. A pilot test at Fatty Basin showed that it was possibleto hatch larvae, rear and introduce juveniles in relatively large numbers, butincreased capacity of the hatchery and further improvement of culture methodsand controls are needed to assure production of the much larger number ofanimals needed for more extensive tests.

- 8 -

A simplified numerical example of each of the two techniques forinitiating a brood stock is given in Appendix 1. The basic concept is tointroduce and maintain a resident population by repeated reintroductions ateach of three target densities that are great enough to ensure mating,survival, and recruitment of a second generation of locally produced, sexuallymature adults.

In lieu of an attempt to start a fishery initially, the annualproduction in excess of mortality from a small, localized, adequatelyreproducing population (nursery stock), once it is established, could be usedto provide animals for successive introductions at other sites. This strategywould also lead to a fishery eventually at a reduced risk since the initialinvestment is relatively low.

Past experience with other introduced species such as oysters,indicates that chance factors in anyone year could prevent adequate survivaland recruitment in that year. Hence, lobster transplants must be repeatedannually during several successive years. It is estimated that at least fiveannual transplants of adult or juvenile lobsters would be required toestablish a permanent colony. In actual practice it may prove necessary tocontinue liberating or seeding for longer periods as with oysters.

It would be expedient to seed an area with both adults and juvenilessimultaneously. Use of each method separately is scientifically desirablesince it permits valid inferences on efficiency and comparison of resultsobtained with each technique. However, the primary aspect of the hypothesisthat we have defined is to examine whether a fishery can be started. Precisescient Hie comparisons are therefore second priority and may be postponeduntil after establishing a reproducing and increasing population of lobsters inthe Pacific by any means whatsoever.

Assuming that an initial adult introduction is made in May, somefemales would extrude eggs in the autumn of that year as a result of matingsthat took place during the previous year in the Atlantic. These eggs wouldhatch as first stage larvae in the following May-August period; so yearlyintervals for an adult transplant are from May (year 0) to May (year 1).Juvenile introductions would be made during July-September (year 0).

2. Practical Sites for the Introduction and Establishment of Lobsters on theBritish Columbia Coast

Although many areas are not suitable, there are several sites whereacceptable conditions are likely to exist.

Using biological evidence such as the persistence of populations ofbenthic animals with pelagic larval stages (flatfish, crabs, oysters, clams),available physical measurements of currents, temperatures and salinities,indications of conservation of warmer than average water, and on the basis ofconsultation with oceanographers and other experts, we inspected the charts ofthe British Columbia coast and listed some sites (Table 1) that might be usedfor a lobster transplant. (Major literature sources of this information are:

- 9 -

Thomson and Van Cleve, 1936; Barber, 1937; Ketchen, 1956; Cameron, 1957;Butler, 1961; Pickard, 1961; 1963; Hollister, 1964; Quayle, 1964; Crean, 1967;Parsons, 1967.)

Table 1. A partial l1st of possible sites.

Large sites Small sites

Total area> 100 sq n. miles Total area < 20 sq n. miles

Hecate StraitBarkley SoundKyuquot SoundQuatsino SoundS. Queen Charlotte StraitN. Queen Charlotte Strait

Baynes SoundNaden HarbourGorge HarbourParts of Seymour InletParts of Kingcome InletParts of Masset Inlet

(a) Discussion of Two Specific Localities as Type Examples

Hecate Strait, an example of a large site, is roughly 40 nautical mileswide by about 200 miles long (8,000 sq miles; Ketchen, 1956). The area southof Skidegate Inlet (about 6,000 sq miles) is particularly suitable for lobsterssince hydrographic conditions are more favourable there and the extent of rockand sand bottom substrate at shallow depths (10·15 fms) is greater than in thenorthern section. Pockets of suitable lobster habitat may also exist withinthe predominant ly smooth sandy area of the north. Minimum and maximumestimates of area suitable for lobsters (Table 2) in the enUre and southernsection of the strait are based on geological studies at Fatty Basin(Appendix II) and reasonable conjecture.

Table 2. Total area and area of bottom suitable for lobstersin Hecate Strait.

Total area of bottom

Area suitable for lobsters: MinimumArea suitable for lobsters: Maximum

Entire Strait(sq n. miles)

8,000

1,6004,000

Area south ofSkidegate Inlet

(sq n. miles)

6,000

1,2003,000

- 10 -

Temperature and salinity ranges of both surface and bottom watersare within acceptable limits; depths (avo 15 fms) and bottom substrate types(rough, gravel, rock, shells and sand) particularly in the southern portion(south of Skidegate Inlet) are satisfactory.

Surface circulation is anticlockwise and conservative. This is shownby Hecate Strait Model studies, drift bottle and other direct current measure­ments. It is also confirmed by biological data consisting of: (1) populationsof lemon "sole" (Parophrys vetulus) in the northern part of Hecate Strait thatoriginate from spawn carried there by surface current from spawning areas inthe southern section and possibly Queen Charlotte Sound; (2) the distributionpattern of an introduced Atlantic clam <1TL! arenaria) which has establisheditself along the entire mainland in Hecate Strait as well as other sectionsof the B.C. coast. The rate of northward movement during summer is estimatedat 0 to 4 n. miles per day, depending on direction and strength of prevailingwinds (Thompson and Van Cleve, 1936; Ketchen, 1956; Barber, 1957; Cameron,1957; Quayle, 1957; Bell, 1963; Crean, 1967). From the pattern and rate ofpassive transport and known rate of development to benthic stage (e.g., 4weeks) it is apparent that lobster larvae would be conserved within theHecate Strait system. For example, if a brood stock were established in theextreme southeast end of the Strait, larvae produced there would settle alongthe coast at distances of, on the average, 56 miles and never more than112 miles. From this it can be deduced that simultaneous introductions atseveral points are needed in order to obtain population recruitment andeventual establishment of a lobster fishery in this section of Hecate Strait,providing reverse gyres are frequent enough to retain the larvae within thissection of the coast during several years.

Baynes Sound, an example of a small site, also appears to haveacceptable habitat characteristics. Total area is 20 sq miles and on thebasis of the same reasoning as that used for Hecate Strait, an estimated4-10 sq miles are potentially useful for lobsters.

3. Scale of the Transplant

Two markedly different scales are required, depending on the objectiveof the initial introduction. If the goal is to initially establish acommercial population over a wide area at once, choice of a large site, suchas southern Hecate Strait is indicated. On the other hand, if the decisionis to provide a relatively small reproducing nursery, brood stock for eventualuse in seeding a larger area, a small site such as Baynes Sound is mostdesirable.

Consideration of passive transport during a 4-week pelagic larvalperiod indicates that it might be necessary to establish a population along56-112 mUes of coastline in an area such as southern Hecate Strait. Usingfrom subtidal to 1 mile offshore as a convenient limit, and if as little as20t or as much as 50t of this area can be used by lobsters, gives 11.2-56.0 sqmiles as an estimated range of total bottom area that must be colonized.

In a small site, like Baynes Sound, the entire area suitable forlobsters (4-10 sq miles: Table 2) would be used for the initial transplant.

- II -

Table 3 (based on Appendix I) is an estimate of the total number ofadult or juvenile animals needed for a 5-year experiment at each site.

Table 3. Range in total number of adult or juvenile lobstersintroduced over 5 years that are required to establish broodstocks at indicated east coast population density in large or

small site. 1

1. Southern Hecate Strait:

Area to be colonized in the initial introduction:11.2-56.0 sq n. miles

Adults

Minimum density 387,520- 1,937,600Maximum density 2,228,800-11,144,000

Median density 974,400- 4,872,000

Juveniles

5,600,000- 56,000,00032,480,000-324,800,000

14,560,000-145,600,000

2. Baynes Sound:

Area to be colonized in the initial introduction:4-10 sq n. miles

Minimum densityMaximum density

Median density

~

138,400- 346,000796,000-1,990,000

348,000- 870,000

Juveniles

2,000,000-10,000,00011,600,000-58,000,000

5,200,000-26,000,000

lNote: Upper limit of adults set by size of area only; upperlimit of juveniles determined by both~ (maximumand survival (minimum) to 4 years - Appendix I.

Median or greater initial stocking densities are clearly preferable.The larger the number of animals introduced, the greater the assurance thatchance factors will not reduce nwnbers to a point that inhibits or preventsadequate mating and recruitment. However it may be necessary, because of cost,to accept the biological risk and use minimal or lesser stocking densities.

Juveniles should be used simultaneously with adults to increase chanceof success. Present economics of lowest survival to age 4 years

(Js <; .05) confirms the need for further development and test of~+lr" 7a.t.

this technique.

- 12 -

An adult transplant at Hecate Strait level would require 51. or moreof the total east coast annual production in anyone year to attain medianstock density during the initial introduction; in an experimental area thesize of Baynes Sound less than 1'7. would suffice.

4. Decisions and Economics

Decisions regarding scale, choice of experimental design and theeconomic objective of a transplant are largely determined by the likelihoodof success.

Estimates of the likelihood of success are subjective. No one hasyet discovered anything that indicates lobsters can It survive and reproducein the Pacific, but testing the feasibility of estabUshing a successfulfishery requires a transplant on a very large scale. This has not yet beenattempted.

The bade hypothesis to be tested is whether birth rate andrecruitment in a Pacific area exceeds the losses by death and emigration.This can be assessed with data from net tOW's and trapping which would ,provideestimates of production and mortality at different stages (Appendix I).Thus, year by year the status of the colony can be assessed and decisions·can be adjusted to suit circumstances.

SUHHARY

The feasibility of establishing a Pacific lobster fishery will bejudged primarily on an economic appraisal. In the past, experiments wereconcerned with demonstrating that it is biologically possible to introducelobsters and none has dealt with the bade problem of populationreproduction and profit. It is our view that continued research on thepattern and scale of the past is unlikely to add materially to presentknowledge (1908 to 1971 > 60 years) and will not test the likelihood ofstarting a lobster fishery. Another approach is therefore required.

Best available estimates, educated inferences, and actual measure­ments of ecological parameters indicate that an experiment of the type andat the scale and sites we have discussed in this paper is biologicallypracticable.

- 13-

REFERENCES

Adams, J. R. 1948. An i.nterim report on an experiment to introduce Atlanticlobsters into Canadian Pacific coast waters. Mimeo Rep., BioI. Sta.,Naoaimo, B.C. 24 p.

Barber, F. G. 1957. The effect of the prevailing winds on the inshore watermasses of the Hecate Strait region, B.C. J. Fish. Res. Rd. Canada14(6), 945-952.

Bell, W. H. 1963. Hecate Hodel. Annual Rept., Fish. Res. Rd. Canada,Pacific Oceanographic Group. p. 50-56.

Butler, T. H. 1961. Growth and age determination of the Pacific edible crabCancer magister Dana. J. Fish. Res. Bd. Canada 18(5): 873-891.

Butler, T. H. 19648. Rc·examination of past attempts to introduce lobsterson the British Columbia coast. Fish. Res. Rd. Canada HS Rep. (Bio1.)no. 775, 6 p.

Cameron, Frances Ella. 1957. Sane factors influencing the distribution ofpelagic copepods in the Queen Charlotte Islands area. J. Fish. Res. Bd.Canada 14(2), 165-202.

Crean, P. B. 1967. Physical oceanography of Dixon Entrance, British Columbia.Bull. Fish. Res. Rd. Canada 156, 66 p.

Faulkner, A. B. 1958. Letter to Dr. A. W. Needler, Director, PacificBiological Station, Nanaimo, B.C., which describes the history andaccomplishments of the II Prince Rupert Lobster and Oyster Company. II

Fraser, C. McLean. 1916. Possible lobster planting areas on the east coastof Vancouver Island. B.C. Contrib. Can. BioI. 1914-1915: 119-132.

Ghelardi, R. J. 1967. Progress report on the 1965 and 1966 lobster introductionsat Fatty Basin, Vancouver Island, British Columbia. Fish. Res. Bd.Canada Tech.Rep. 44, 37 p.

Hollister, H. J. 1964. Classification of monthly mean sea surfacetemperatures and salinities at shore stations along the British Columbiaand adjacent American coasts, 1915-1962. Fish. Res. Bd. Canada HS Rept.(Oceanog. and Limnol.) 177. 123 p.

Ketchen, K. S. 1956. Factors influencing the survival of the lemon sole(Parophrys vetulus) in Hecate Strait, British Columbia. J. Fish. Res.Bd. Canada 13(5), 647-694.

Parsons, T. R. 1965. A general description of sane factors governing primaryproduction in the Strait of Georgia, Hecate Strait and Queen CharlotteSound, and the N.E. Pacific Ocean. Fish. Res. Bd. Canada MS Rep.(Oceanog. and Limnol.) 193, 34 p.

- 14 -

Pickard, G. L. 1961. Oceanographic features of inlets in the BritishColumbia mainland coast. J. Fish. Res. Bd. Canada 18(6}: 907-999.

Quayle, D. B. 1964. Distribution of introduced marine mollusca in BritishColumbia waters. J. Fish. Res. Bd. Canada 21(5): 1155-1166.

Rutherford, J. B" D. G. Wilder, and H. C. Frick. 1967. An economicappraisal of the Canadian lobster fishery. Fish. Res. Bd. Canada,Bull. 157 J 126 p.

Scarratt, D. J. 1964. Abundance and distribution of lobster larvae (Homarusamericanus) in Northumberland Strait. J. Fish. Res. Bd. Canada 21:661-680.

Scarratt, D. J. 1968. Distribution of lobster larvae off Pictou, N.S.J. Fish. Res. Rd. Canada 25: 427-430.

Thompson, w. F' J and R. Van Cleve. 1936. Ufe history of the Pacific halibut2. Distribution and early life history. Rep. Internat. Fish. CClDE.No.9, 184 p. (Seattle)

- 15 -

APPENDIX

Discussion and numerical examples of two simplified designs

for a lobster introduction using adults (total length: 7-9 inches)

or juveniles (stage 4+1/2) for initial seeding.

A)~

ADO,l,a ••• x

Min. D

Max.

Hed. 0

AmO-+l,.................

x-+y

- 16 -

• Adult population dendty (number of legal-.ize lobster.per .q nautical mile at the end of any given year 0, 1,2 ••• x after -eeding and before re-introduction.

• Minimum eut coa.t valuu for population density(number of pound. or individuals of legal .ize -­l.e., 7-9 inches total length per .q nautical mile~

• Maximum ea.t coa.t population deneity, legal... izelob.ter••

• ~ .alt coa.t population deneity, legal-.he lobster ••

• Initial -eeding (number) of legal-.ize adult. requiredto achieve population densit1e. equal to~,~, !!!!!!!!!l ea.t coa.t valuu ! .I!!! after initialintroduction

o~

mO"'l

where D is defined as Hin. D, or Max. D, or Med. D.

• A ADml-+ a 0

• Number of adults per sq nautical mile that mu.t bere-introduced at the end of year l~ 2 to maintainselected population density.

• Number to be re.. introduced at year 2-- 3.

• Number to be re.. introduced at end of year 3~ 4.

Actual annual adult mortality (inclUding both death and• emigration) during year 0.... 1, 1-+2 .•. x-.y of

introduction.

- 17 -

Lml-. a ,a ....3 ,3~{4+Va)

_ Actual interstage mortality rate during stage 1--+ 2,2--.3, 3--. (4+¥».

Jm(4+l/a>....1, 1-+2 ,2~3

• Actual annual mortality of juveniles from stage (4+'1/2)(first benthic)-1I> age 1 year; 1...., 2 years; 2-t> 3 years;3~ 4 years (first reproduction).

_ Survival (annual) - 1 - m.

- Density of (4+1/2) stage, 1 year, 2 year juveniles at0,1,2 ..• x years after seeding.

ADo

B) Assumptions

I. A • .60mO-.1

2. A • .25ml-t2J2~3 ••• >l--+y

3. Sex ratio 1:1

- 18 -

4. Proportion berried females· .65

5. 'X Total length, females ~ 20.3 em (8 inches)

'X Carapace length, females "d 7.0 em (2 3/. inches)

6. x: Number of eggs per female· 5,000

7. 1004 hatching success, i.e., number of eggs· number of r,..

8. Nature

L - .50ml-;,a

L - .79ml-i'3

Hatchery

.15 to .45

.25 to .70

.30 to .80

9. J •• 60 to .80m(4+l/a ) ..... 1 year

J •• 50 to .60rol ., ...r~a ".r.

J........ - .30

• .25

- .90 to .95

10. Most of hatch (98't) occurs in 7-day period during Hay 23-August 30(.14/day).

11. 4,3,31. In top 3 feet of water column after hatching.

12. Number of days required from stage 1 to stage (4¥h) (benthic)expressed by:

10810 y - 3.605 - 1.9207 log x ,

where y - time in days to stage (4+1/ a); x • temperature during larvalperiod; SE •• 238 days.

13. x Weight of 8-inch (total length) lobsters - lla lb.

- 19 -

14. Hin. D - 5 X 1()3 Ib ~ 10 X 1()3 individuals per sq nautical mile.

Max. D • 28.8 X 103 Ib .£!. 57.6 X 1()3 individuals per sq nautical mile.

Med. D II: 12.55 X lQ3 Ib £!. 25.1 X 103 individuals per sq nautical mile.

15. Sexual maturity - Age 4 years (age of first reproduction).

C) Discussion

The assumptions (1-15) that provide the basis for design and numericalexamples are simple but realistic. Hlgh lnitial mortality of adults(A - .60) in the first year after introduction was observed 1n both of themO~l

releases made at Fatty Basin (1966, 1967, data on file). The 2nd, 4th, 5th, 7th,8th, 9th, 10th, and 13th assumptions are either based on field and hatcheryinformation from studies at Fatty Basin (data on file) J these combined with eastcoast estimates, intuitive guesses, or all three. Assumption 3 (1: 1 sex ratio)is an east coast statistic; the 6th is based on the relation 10glo y (fecundity) ­-1.6017 + 10glo x, where x - carapace length in millimeters (Saila et a1. 1969);

the 11th is supported by east coast and Fatty Basin plankton tow studies; the12th, expressing relationship between temperature and number of days requiredto moult three times to the (4..p-!2) (benthic) stage is given by Taylor (1950)based on observations in the laboratory.

Few, if any, of these assumptions can be considered precise or sharplydefined values of the parameters in question and several (e.g., juvenilemortality J - .90 to .95) consist of measurements made on

m("'+1/2~ , .. ,.groups of animals- in pens and cages (lowest estimate of mortality - .90) and areasonable guess (highest estimate - .95 - population replacement under statedassumptions). They do, however, represent the most complete informationavailable at this time and are probably in the right ball park. Minimum esstcoast density (Min. D), maximum (Max. D), and median (Med. D) are taken fromTable III of Rutherford, Wilder and Frick (1967) and represent values for Gaspe,western Nova Scotia, and South Shore Nova Scotia + Strait, divided by 2,respectively. Sexual maturity at age 4 years is based on evidence cited forsome areas by the same authors.

The designs and numerical examples are simplified to increaseefficiency of illustrations and carmunication. They can be made more precise bysubstituting values from serial measurements over longer periods of time forthose now based on guesses or short-term observation. Complexity' can beincreased by considering effects of age on reproduction, life span of reproduction,total number of reproductions occurring, effect of quality (e.g., 'stamina' orcondition) on survival of benthic juveniles raised in hatchery before release,initial and repeated seedings made on monthly -- rather than yearly -- basis,sexual maturity at 5 or more instead of 4 years, and a host of otherpossibilities not included here. Another alternative is the use of a combinationof strategies such as making an initial seeding at max. or med. density and

- 20 -

subsequent re-introduction at a minimum level of replacement (P2'3'... I J.Our intention in this first exposition is merely to present a preliminarybade design for testing the hypothesis regarding establishment of acOtmlercial lobster fishery In the Pacific rather than to give a ccxnpletedisquisition of all the reasonable alternatives and possibilities. These canbe presented later if interest and circumstances warrant. it.

Numerical examples of designs based on seeding with adults are givenseparately from those using juveniles (stage (4+lJa». In practice these maybe combined. Basically the designs consist of repeated introductions ofadults or juveniles in quantities and at intervals consistent with assumptionsgiven in the preceding section. The objective of each is to achieve a self­sustaining population of lobsters equivalent to a chosen east coast (minimum,maximum or median) density value.

The numerical examples also provide an opportunity to evaluate andselect a suitable scale -- including choice of level (Kin. D, Kax. D, Ked. 0)and type (adult or juvenile) of seeding, densities, length of experiment, andcriteria for decisions regarding continuance or abandonment of the project atany stage including the first year after inception of the project. The calcu­lations are presented on the basis of 1 sq nautical mile; total values orquantities for a specific experimental site can be obtained by multiplyingthese by the appropriate factor (e.g., total square nautical miles inexperimental area).

The~ design (section 0) starts (row 2, columns I, 3, 5) with thetotal number of animals which must be introduced initially to achieve thestated density (Min. D, Max. D, Hed. 0, row 1) one year later under assumption(Atno~l .s; .60). Subsequent re-introductions (Pa , P3 , p... ) are made at the end

of year 1~2, 2""";>3, 3--3114, and the number of animals in each re-introductionis based on target density and assumed actual annual mortalities (death +emigration) during intervals 0-->1 - .60, 1--;"2, 2~3 •.• x.......y - .25 forthe initial and subsequent introduction. There are no re-introductions at theend of year O~l because losses were taken into account in the original'over-seeding' given as Po (row 1). Stock size (AD i a,3, ... ) at each level ofdensity before replacement by re-introducing adults hom the east is given inrows 7-11.

Length of the adult experiment is 5 years. This is because the firsthatching of the Fi generation occurs at the end of year O~l (start ofyear 2); progeny of this hatching (Fa) would supposedly reach sexual maturi.tyat the age of 4 years (5 years after initial hatching), and these (Fa) larvaewould hatch the following year (start of year 6) completing the oneregenerative cycle of population reproduction demanded by the hypothesis.

Theoretical reproduction and recruitment (total number of: berriedfemales, eggs, four larval and three (J' (4+1/a), J 1 year, J 2 years) stages,sexually mature adults (age 4 years) produced in 1 sq mile at given seedingdensities are listed. Crude values for larval (I, 2, 3, 4) densities(no./sq nautical mile and no./cubic foot) under assumptions 8, 11, and 12are shown at the bottom of the table.

• 21 •

To illustrate (rounded values), at minimwn east coast stock density(Min. 0), 25,000 (ADo> adult lobsters per sq nautical mUe are introducedinitially (Po)' none at the end of year O~l, 2,500 (Pa ) at the end ofyear 1~2J 3,400 (P3) at termination of year 2......,.3; 3,700 (P.> at the final(beginning of year 4) period for a total of 34,600 lobsters per sq nautical mileintroduced over 4 of the 5 total years of the experiment. Population size atthe end of each year subsequent to initial seeding and~ replacement (byrelease of new adults frcxn the east) is:

ADo - 1.0 X LD4/sq nautical mile at end of year 1AD

1'" 7.5 X l03/sq nautical mUe at end of year 2

ADa = 6.6 X lQ3/sq nautical mile at end of year 3ADa - 6.3 X l03/sq nautical mile at end of year 4

RepLacements are calculated to increase density to prescribed level(l04/sq nautical mile) at the beginning of each reproductive year following(2, 3, 4, 5).

Reproduction and recruitment at minimum stock density under assumptionsyields 3,250 berried females per sq nautical mile, hatching 16.9 X 1()6 eggs II: I.,.;under stated values for stage mortality (assumption 8) these would resultin 8.5 X loeI...:a, 3.6 X loe~, 16.9 X 104J(4+l/3) per sq mile; this number

(16.9 X 1(4) of early benthic «4+1/3) stage) juveniles, operating undermortalities listed in assumption 9, would yield from 3.4 to 6.8 X 10

4

l-year-olds(J1) Fa generation, 13.6 to 34 X lO" 2-year-olds (Ja)J 9.5 to 23.8 Xloa 3-year-olds (J

3) per sq nautical mile. Assuming .14 of total hatch

occurring on anyone day (7-day hatching period) gives pelagic larval densitieson anyone day during hatching period equal to:

Pelagic

stage

L, .1

L" ·1

r" .1

r.. .1

Number

per sq n. mile

2.4 X 106

1.2 X 108

5.0 X 10&

2.4 X 1()4

per cu. ft

2.2 X 10~a

1.1 X 10- 2

4.6 X 10.3

2.2X 10- 4

Figures for seeding densities equal to maximum and median east coast values maybe examined in the same way.

The juvenile design (section E) consists of repeated introductions overa period of 5 years with stage (4+1/2) early (just) benthic animals reared inwest coast hatcheries. The number of juveniles that must be introduced per sqmile to achieve noted stock densities are based on assumption 9 (J

m(4+1/~4 "un

II: .90 based on observations in pens at Fatty Basin, and .95, an intuitive guessbased on population replacement where recruitment - death). The number of

- 22 -

juveniles required to achieve minimum, maximum, median stock densitiesunder each of these two mortality schedules are given in rOW's 4 and S,columns 1, 2, and 3.

Range of survival from stage 1 to stage (4~/2) has been observedin the Fatty Basin Hatchery as .20 to .70; total number of stage 1 animals(eggs) required to produce the needed numbers of stage (4+312) for seedingand the number of berried females of average length" 8 inches required toprovide these are given in rows 12 and 13. Larger females (e.g., 16-20inches total length) with more eggs per female, would reduce the number ofberried animals needed.

Following the same procedure as that used for adults, a minimumtarget stock density (lQ4 adult lobsters/sq nautical mile) would require1()6 stage (4+1/3) seeded, obtained from 1.4 X 1()!5 to 5.0 X 1()6 stage 1obtained from 28 to 100 females depending on whether hatchery survival(~-)40) was .70 or .20 respectively with Jm(4+1/2)~40 "",,- .90 (5 - .10).

At Jm(4+1/2)~40 1t1.r."" .95 (5 = .05),2 X l()f> stage (4+1/:a), and

2.8 X 1()6 to 1()8 stage 1 from 56 to 200 8-inch (total length) females areneeded. The same logic applies to values for maximum (57.6 X 103 adults persq nautical mile) and median (25.1 X 103 per sq nautical mile) densities.

Total length of the juvenile experiment is 8 years. An F1 juvenileseeding in year 0 achieves sexual maturity 3 years later when the firstF1 mating occurs (during year 3~); progeny (Fa) from this mating hatchthe following year (year 4 after seeding) and reach sexual maturity 4 yearsafter that (8 years after initial) at which time the first Fa mating occurswhich will hatch the beginning of the year following (year 9) to completetwo reproductive cycles.

To make this experiment roughly equivalent with the adult method,stage (4+1/2) juveniles would be introduced at the indicated level foryears 0, I, 2, 3, 4. Thus at minimum stock levels, between 1()6 and 2 X 1()6juveniles would be introduced per sq nautical mile or 5 X 1()6 to lOs per sqmile over the 5-year period.

Tests of the hypothesis that Pacific birth rates:) Pacific deathrates consist of field data estimates that show hatching of stage 1 (1,) andage specific mortality rates are..tE;; those given in assumptions:

1. Number of larvae born in years 0--;:>1 :> mortality of larvaeto adult stage~ mortality of adults during intervalyear l~.

2. A ... 60"0-+1

- 23 -

3. A ., .25ml_41J2~3J x~y

4. J ., .60 to .80m(,,+1/a )-1> 1 ,.ct.'

5. J ., .50 to .60m,,. •• ' .... :2 7.'"

6. J ., .30""'~3 ,. ... r.

7. J .. .25m,~.

8. Jm(4+1/a ) ........

<; .90 to .95

Use of these predictions, modified by whatever degree of realismthat observed cirCUMstance dictates, permits examination of the project ateach yearly stage (including the first) and provides a logical basis for thedecision to abandon the project at that -- or continue to the next stage ofthe experiment.

D) Adult introduction. A numerical example based experimental area of one square nautical mile.

ADo (Target F] Density)

Pop.p.p.

Total (S years)

Population SizeAD1AD.AD.AD.

Reproduction and RecruitmentBerried females

Lt.1La. 1r".1J(Hl1.) .1

J 1 • 1Ja ' lJ3 • 1

Daily Larval Density duringHatchinJt Period

Lt .1La.1r".1I"..1

Minimum Maximum Median

(X loa individuals per (X loa individuals per (X !03 individuals persq n. mile) sq n. mile) sq n. mile)

10.0 57.6 25.125.0 144.0 63.0

2.5 14.4 6.33.4 19.4 8.53.7 21.2 9.2

34.6 199.0 87.0

10.0 57.6 25.17.5 43.2 18.86.6 38.2 16.66.3 36.4 15.9

~3.3 18.7 8.2

16900.0 97300.0 42600.08500.0 48700.0 21300.03600.0 20400.0 8900.0

169.0 973.0 426.0

34.0-68.0 195.0-389.0 85.0-170.013.6-34.0 78.0-194.5 34.0-85.09.5-23.8 54.6-136.1 23.8-59.6

Thousands No. (X 10-·) Thousands No. (X 10-') Thousands No. (X 10-·)per sq per ft3 per sq per ft3 per sq per ft3

....!l.:....!!! ~ ~ ---2400 2.2 13600 12.3 6000 5.41200 1.1 6800 6.2 3000 2.8500 .46 2900 2.6 1250 1.2

24 .02 136 .12 60 .05

- 25 -

E) Juvenile (stage (4+1/2» introduction. A numerical example based on anexperimental area of one square nautical mile.

Minimum Maximum. Kedian

(x 1()3 individuals per sq nautical mile)

AD. (Target F1 adult density)

Number of J (4+ 1/2) introduced

per year at:

J. .90Col" 1/2)".

J. ,. .95(4+1/a)".

Number of L1 required peryear at:

L. - .301.,(4+ l/a)

L : .80-1-t(4+ 1J2}

Number of berried 03'') femalesrequired per year at:

L' 1,<4. ,/.,) •. 30

L' ..<4.'!.,) •. 70

Totals (for 5 year experiment)

Females (8")

10.0

100.0

200.0

140-280

500-1000

0.280_0.560

0.100-0.200

500-1000

700-5000

0.140-1. 000

57.6

580.0

1160.0

830-1700

2900-5800

0.170-0.340

0.580-1.160

2900-5800

4200-29000

0.850-5.800

25.1

250.0

500.0

360-720

1300-2600

.072_0.144

0.260-0.520

1300-2600

1800-13000

1.300-2.600

- 27 -

APPENDIX II

List of problems studied in the current (l966-1971)

lobster investigation.

- 28 -

A) Environmental and other background studies

1. Physical Oceanography

(a) "Oceanographic phase of the Fatty Basin study for a lobstertransplant .-

by: R. H. RerUnveux (1966)Fish. Res. Bel. CanadaMS Rept. (Oceanogr. and Limnol.) No. 228.

2. Geology

(a) "Geological setting and superficial sediments of Fatty Basin,a shallow inlet on the west coast of Vancouver Island. BritishColumbia. II

by: W. Wiese (1971)MSc ThesisDept. of GeologyUniversity of British Columbia

3. Biological Oceanography

(a) "Biolo ieal observations in Fatt Basin Vancouver Island,British Columbia, 19 9.

by: M. Hardon (1969)Fish. Res. Bd. CanadaMS Rept. Series No. 1051

4. Microbiology

(a) "Microbiological studies relevant to a lobster introductioninto Fatty Basin, British Colwnbia. Ii

by: H. Seki and M. Rardon (1970)J. Oceanogr. Soc. Jap. 26(1): 38-51

B) Lobster studies - data on file

(a) Design, test, cost analysis of improved methods for procurement,quarantine, shipment, and release.

- 29-

(b) Population statistics (1961 to 1971) of a free cohort 1nFatty Basin.

( 1) popu1.t ion she(ii) mortality rate

(iii) fecundity(iv) growth

(v) predation by mink and otter(vi) hatching

(c) Behaviour.

(1) "A coistie behaviour of the American lobsteramericanus (Hilne Edwards .

by: J. C. Scrivener (1971)MSc Thesis,Dept. of BiologyUniversity of Victoria

Also published as: Fish. Res. Bd. CanadaTech. Rept. 235.

(ii) Movement within and emigration out of Fatty Basin.

(iU) Effect of release methods on movement and survivaL

(iv) Relationship between activity-catchability and sex,temperature (season), population density, stage ininter.moult cycle.

Cd) Condition and disease.

(1) Serum protein analyses as index of physiologicalcondition.

(ii) Monitoring for presence of Gaffkya homar!.

2, Hatchery

(a) Design, construction, operation,

(b) 1967

(i) Brood stock statistics-Source (SE George's Bank, Prince Edward Island)-Size and number of females-Number died in transit and before hatching-Total eggs

- 30 -

(ii) Hatching statistics-Number of Stage 1 larvae hatched.-Number of Stage 1 larvae used (capacity of hatchery).-Definition of hatching period (season and hour of

day or night.

(iii) Mortality and growth to stages 2, 3, 4, (4+1/2) (firstbenthic)

-Length of inter-moult periods.-Between and within stage mortality rates.-Length increments in succeeding stages.-Total number of benthic stages produced.

(iv) Behaviour of hatchery reared juveniles-Substrate preference experiments.

(c) 1968

(1) Effect of temperature and diet on larval mortality andgrowth.

(ii) Behavioural experiments defining period of change frompe 1agie to benthic phase.

3. Juveniles (Stage (4+1/2), 1, 2, 3 years).

(a) Rearing experiments

(1) Design of methods: float cages, pens, individual com­partments.

(11) Statistics of growth and mortality to sexual maturityin pens and cages.

(b) Juvenile release at Alma Russell

(i) Design of methods.

(11) Observations before and after release-Number released.-Condition.-Behaviour after release.

4. Evaluation of Fatty Basin and Barkley Sound as a suitable site for amajor lobster introduction.

5. Census of crab (Cancer magister, s.. productus, f. gracilis) populationsat Fatty Basin.

- 31 -

6. Shipment of European (Homarus gmmnarus) lobsters from England toNanaimo.

(a) Hatching, rearing of larvae from berried females.