British Columbia Waters Research Articles

Atlantic salmon in the North Pacific

The first catches of Atlantic salmon, Salmo salar L., in British Columbia (BC) waters occurred in 1987. The first reported escape of Atlantic salmon (2000 individuals) occurred in 1988. From 1988 to 1995, 97 799 Atlantic salmon were reported escaped from net pens in BC but the true number was higher as not all escapes are reported. Since 1987 a total of 9096 Atlantic salmon was caught in the coastal marine waters of BC, Washington and Alaska, and 188 were caught in fresh water. Most catches occurred in the Johnstone Strait area, where the abundance of salmon farms is highest. The most distant recovery occurred in 1994 when an Atlantic salmon was caught near the western end of the Alaska Peninsula. There have been no reports of successful reproduction of Atlantic salmon in the wild and no feral juveniles have been found. Atlantic salmon caught in the ocean in BC have substantial amounts of adipose tissue and they are heavier at length than fish caught in Alaska. The proportion of fish with prey items in their stomachs is generally low but higher in Alaska (13.1%) than in BC (5.8%). Most fish caught in fresh water are either maturing or mature.

Application and Advantages of Catamarans for Coastal Patrol Vessels

Although the catamaran hull has been, for the past decade, the predominant choice for ferry designs of increasingly larger dimensions, as well as other applications, its adoption for small patrol craft has been limited. This paper describes the advantages and applicability of the catamaran for typical patrol boat missions, assesses its capital and operating costs versus those of a monohull of equivalent performance, and reviews the experience of a standard series of catamaran patrol boats operating in offshore British Columbia waters by the Royal Canadian Mounted Police. RCMP Commissioner class patrol vessels at speed

First verified record of the Shortfin Mako Shark, Isurus oxyrhinchus, and second records or range extensions for three additional species, from British Columbia waters

First verified record of the Shortfin Mako Shark, Isurus oxyrhinchus, and second records or range extensions for three additional species, from British Columbia waters

Inter- and intrapopulation genetic variation in species ofPorphyra (Rhodophyta: Bangiales) from British Columbia and adjacent waters

Starch gel electrophoresis of 17 proteins has provided data on inter- and intrapopulation genetic variation in 20 species ofPorphyra occurring in British Columbia and adjacent areas.P. cuneiformis andP. nereocystis showed no within species variation, even over ranges of more than 1000 km. Populations ofP. abbottae, P. fallax, P. fucicola, P. gardneri andP. schizophylla were characterized by fixation for certain alleles. The number of polymorphic loci in a population ranged from zero to nine, depending on the species. Six species had populations that were polymorphic at just a single locus. Only two species (P. mumfordii andP. pseudolanceolata) had populations that were polymorphic at more than three loci. These levels of genetic variation are lower than those reported for populations of JapanesePorphyra species. Eleven taxa were polymorphic for 6-phosphogluconate dehydrogenase, the most variable enzyme. No within species polymorphisms were detected for bromoperoxidase, lactate dehydrogenase, superoxide dismutase or phycoerythrin. Possible evidence for the chimeric nature of the thallus was observed only inP. mumfordii.

Nephtys cornuta (Polychaeta: Nephtyidae) and its subspecies, and use of the trinomials in pollution monitoring

The form of Nephtys cornuta separated as the Californian subspecies N. c. franciscana is found widely in British Columbia waters, co-occurring and intergrading with the nominate subspecies N. c. cornuta. Previous identifications to the trinomial have tended to be inaccurate (36% of 127 specimens reexamined). The co-occurring forms show no apparent ecological distinctions relevant to pollution monitoring objectives at one location where the species is both abundant and significant as an indicator of seabed recovery from mine-waste environmental impact. It is concluded that the trinomial, hence subspecific designation, should not be used in the British Columbia area of the species range.

Factors Influencing Development and Survival of Pacific Herring (Clupea harengus pallasi) Eggs and Larvae to Beginning of Exogenous Feeding

The euryplastic Pacific herring (Clupea harengus pallasi) generally encounters temperatures ranging between 0 and 10 °C throughout its distribution during the maturation and spawning of adults, incubation of eggs, and hatching of larvae. For many Asian stocks these events occur in the lower half of the temperature range; with North American stocks they tend to occur in the upper half of the range. In British Columbia waters, salinities associated with these events (range, optimum) are spawning (2.6–28.7‰, 27–28.7‰), [Formula: see text] fertilization of eggs (4.5–42‰, 12–15‰), and maximum total hatch and hatch of viable larvae (4.5–42‰, 12–17‰). A low/low–high/high interaction between salinity and temperature also influences total hatch, hatch of viable larvae, and salinity tolerance of larvae. In addition, the following implications arise regarding aspects of the Pacific herring reproductive cycle, based on previously published and new data, and on speculative inference. The response of Pacific herring to salinity and temperature appears to have a commanding influence on the reproductive cycle and, thereby, on distribution of the species. Survival of eggs on substrate, related to respiratory activity, appears to be influenced by the transport and perfusion velocity of interstitial water in an egg mass. Such transport may involve perivitelline fluid colloid osmotic pressure; natural convection; the surge associated with wave action, beach slope, and depth; and possibly differences in resistance to convective flow of deoxygenated water from an egg mass based on orientation of the substrate. These relations would be modified by variations in deposition intensity (number of egg layers) and packing density (eggs per unit volume), and both factors may affect survival of occluded eggs in an egg mass differentially, depending on the substrate used. A review of data on salinity tolerance of herring larvae indicates that a variety of dosage-mortality techiques has been used, leading to noncomparable estimates of response. An assessment of upper incipient lethal salinities will require standardization of such techniques. Recent studies show that salinity tolerance of larvae is influenced significantly by salinity–temperature conditions during egg incubation. At usual incubation conditions in British Columbia waters, the upper boundary of larval tolerance is estimated as 27.5–31.7‰ S (72-h LC10). depending on incubation history. The fate of Pacific herring larvae carried into the higher salinities of offshore waters has been controversial. In the Strait of Georgia, British Columbia, substantial offshore dispersion of larvae occurs where surface conditions generally are 27–28.6‰ and 9–10 °C in the early larval period. Although these salinities are near the upper boundary of salinity tolerance, larvae sampled in offshore waters (1981) had an apparent mean age of 15 d and were actively feeding and growing. From rates of disappearance of larvae in the offshore waters (9% wk) and inshore waters (45% wk) we conclude that usual surface salinities and food supply in the open waters of the Strait were not a dominant influence on larval survival. Assuming the larvae remain in the upper 10 m, we suspect their disappearance, at least offshore, to be largely the result of predation.

Age Validation Studies on the Spines of the Spurdog (Squalus Acanthias) Using Tetracycline

Elasmobranchs, unlike teleosts, do not possess otoliths or scales suitable for age determination. Various skeletal structures of elasmobranchs have been used in an attempt to find a reliable ageing technique. These include the centra of Raja fusca (Ishiyama, 1951). R. eglanteria (Daiber, 1960), R. erinacea (Richards, Merriman & Calhoun, 1963) and Cetorhinus maximus (Parker & Stott, 1965). Yokota (1951, 1952) has described annual growth increments on the claspers of various elasmobranch species. Stevens (1975) made vertebral ring counts in the blue shark, Prionace glauca L. More recently Jones & Geen (1977a,b), using X-ray spectrometric analysis, have examined the vertebral circuli of dogfish found in British Columbia waters. Methods of age determination, using the spines of the spurdog (Squalus acanthias L.) have been described by Kaganovskaia (1933, 1937), Bonham et al. (1949) and Aasen (1961). All these authors assumed that the more or less regular series of dark bands or ‘rings’, extending from a white pigment-free base of the enamel to near the tip, were annual. Holden & Meadows (1962), on the basis of the internal and external features of the spines, concluded that the dark bands did represent annual growth increments. In particular, they argued that the dark bands were laid down during the winter when growth would be slowest, whereas the faster growth in the summer was represented by the light bands. Holden & Meadows (1962) identified several conditions, e.g. birth, double, false and spawning rings – that made interpretation of the ring structure and subsequent age determination difficult.

An Evaluation of Morphometrics and Meristics for Stock Separation of Pacific Herring (Clupea harengus pallasi)

We conducted an analysis to determine if Pacific herring (Clupea harengus pallasi) stocks occurring in different localities in British Columbia waters could be separated using morphometric and meristic characters. Discriminant function analysis was applied to morphometric and meristic characters taken from food herring samples. Herring found in northern British Columbia waters were detectably different from those found in the Strait of Georgia. We recommend using meristic characters for separation on a broad geographic scale and using "best" morphometric characters for finer resolution within the established broader groups. We defined a set of 12 best morphometric characters for further large-scale studies.

Ctenophores in Salmon Diets

Abstract Ctenophores constituted most of the stomach contents of 50 chum salmon Oncorhynchus keta and one chinook salmon O. tshawytscha caught in British Columbia waters during summer 1981. Ctenophore remains are difficult to identify, and such food may be more important to Pacific salmon than hitherto realized. Received February 10, 1983 Accepted June 15, 1983

Sabellidae (Polychaeta) Principally from the Northeast Pacific Ocean

Morphological and distributional observations are reported for 14 northeast Pacific sabellids, largely using collections from British Columbia and Washington waters, and for one species from New Zealand. For nine of these, additions to the descriptions are provided based on type material. Eudistylia Bush is revised using a new combination of diagnostic characters. Eudistylia catharinae is newly described; E. tenella Bush is regarded as a synonym of E. vancouveri (Kinberg). Diagnostic characters at the generic level, particularly those of Sabella Linnæus, are discussed. Demonax Kinberg, considered to be a subgenus of Sabella, is emended. Distylia volutacornis pacifica Berkeley and Berkeley is elevated to specific rank and referred to Demonax. Jasmineira pacifica Annenkova, Oriopsis gracilis Hartman, and an unnamed species of Sabellastarte Savigny are new additions to the polychaete fauna of British Columbia and Washington. Key words: British Columbia, Demonax, Eudistylia, northeast Pacific, Polychaeta, Sabella, Sabellidae, Washington

Population Dynamics of Spiny Dogfish (Squalus acanthias) in British Columbia Waters

An age-structure model that incorporates recent information regarding growth and reproduction has been developed to investigate the dynamics of spiny dogfish (Squalus acanthias) populations in British Columbia waters. Mechanisms for density-dependent regulation of abundance were evaluated on the basis of theoretical effectiveness and ability to predict observed patterns in simulations of the historical fishery. Compensatory change in the rate of natural mortality appears to be the principal mechanism for density-dependent response. The instantaneous rate of natural mortality at natural equilibrium was estimated to be 0.094 MSY for British Columbia waters is ~ 9000–11 000 t/yr. The minimum size at entry to the fishery has little effect on MSY. Sustained-effort, sustained-yield, and periodic fisheries were modeled to determine optimum harvesting strategies. Periodic fisheries were found to vary widely in feasibility and appear to be impractical from a management perspective whereas a sustained-effort fishery would ensure maximum stability. Key words: spiny dogfish, population dynamics, age-structure model, density-dependence, simulation model, commercial fishing strategies

Food and Feeding of Spiny Dogfish (Squalus acanthias) in British Columbia Waters

Stomach content data on 14,796 spiny dogfish (Squalus acanthias) from British Columbia waters are presented. The major dietary components based on occurrence were 55% teleosts, 35% crustaceans, and 5% molluscs. The principal food items were herring (22%) and euphausiids (14%). Prey was largely pelagic (80%), with fishes predominating in winter and invertebrates in summer. Fishes became more important in the diet with increasing dogfish size. Dogfish consumed twice as much food in summer as in winter. Annual consumption varied from 5 times biomass for small dogfish to 2.5 times for larger animals. Preliminary analyses suggest that dogfish consume over 5 times the current annual commercial catch of herring, but insignificant quantities of salmon. Key words: dogfish, Squalus, feeding, food, biomass, predation, metabolism, seasonality, survivorship, digestion

Salmon Fishing Terms in British Columbia

LIS PAPERPROPOSESto discuss the technical vocabulary peculiar to the sport of salmon fishing in the rivers and coastal waters of southern British Columbia. There are five species of salmon found in British Columbia waters, four of these much sought after by sports fishermen; as a result, a distinctive and colourful vocabulary has arisen in this area of English-speaking Canada. Each species has several common names as well as the biological Latin one, often differing from the terms by which it is known immediately to the south in the state of Washington, or to the north in Alaska; these names are frequently of local Indian origin. In addition, there are numerous names within the species that, to the devotee of the art, indicate the age, size, or state of maturity of the fish. At least two of these terms have an ancient history in the sport of angling; their exact etymology is obscure, but cognates are to be found in other northern Indo-European languages. In addition to fish names, the sport has spawned a variety of specialized methods and tackle, all carefully and specifically named, and in large part unknown to the rest of English-speaking North America. As can be expected, there are specific differences among the various forms of Canadian and American English. The fact of such differences in the lexical spectrum can be underscored by the unique ethnolinguistic paradigm exhibited by British Columbians in respect to the sub-culture associated with salmon fishing. Indeed, such lexical differences not only provide an interesting example of variation across the isogloss boundaries already established by the American-Canadian border, but also serve as an example of western Canadian English differences from other English-speaking areas within Canada itself. Atlantic and Pacific salmon are both of the family Salmonidae, but while the Atlantic salmon and the several species of trout found in the Pacific north-west all belong to the genus Salmo, the Pacific salmon is genus Onchorhynchus, so called because of the characteristic hooked nose developed during spawning. There are five species of Onchorhynchus found in British Columbia waters: sockeye (0. nerka),

Size at Maturity, Fecundity, and Embryonic Growth of the Spiny Dogfish (Squalus acanthias) in British Columbia Waters

Information on the biology of dogfish in British Columbia waters, none of it previously reported, is compared with similar information from other areas of the North Pacific as well as the North Atlantic.Males and females on both sides of the Pacific have an approximate maximum size of 100 and 130 cm, respectively, or at least 10 cm greater than in the North Atlantic. Females in the North Pacific mature at an average length of 92–100 cm depending on region, as compared to 77–82 cm in the North Atlantic. Males likewise mature at a larger size in the North Pacific.Observations in Canadian west coast waters show a weak correlation between number of embryos and length of the mother (r = 0.57).Female dogfish produce 2–17 young with an average of 6–7 in the North Pacific off the British Columbia coast; 3–25, averaging 12 in the Sea of Japan; 1–9, averaging 4 in the northwest Atlantic; and 1–10, averaging 3–5 in the northeast Atlantic. Size at birth is about the same throughout the northern hemisphere being between 23 and 30 cm with an average of 25–27 cm.Intrauterine growth rate is essentially the same in all regions, but at any given time of year differences is size are substantial and are determined largely by differences in time of conception.

First Records of the Striped Bass, Morone saxatilis, in British Columbia Waters

Two specimens of the striped bass (Morone saxatilis) were taken in British Columbia waters in 1971. One was taken off Port San Juan (48°30′N, 124°30′W) and one in Barkley Sound (48°58′N, 125°03′W). Previous most northerly published record for the Pacific coast was from Puget Sound, Washington.

The Black Hagfish, Eptatretus deani, from British Columbia

The first two specimens of the black hagfish, Eptatretus deani (Evermann and Goldsborough), taken in British Columbia waters are reported and described.

A checklist of polychaeta recorded from British Columbia since 1923, with references to name changes, descriptions, and synonymies. I. Errantia.

A hundred and eighty species of Polychaeta Errantia comprise this list. A majority of them were included in a contribution to the Canadian Pacific Fauna Series (No. 9b(1)) published by my wife and self in 1948, but, not only have a number of others been described from British Columbia since then, but also there have been many modifications of classification and nomenclature suggested by other workers in the field. The purpose of the present list is to bring together all the species recorded by us from British Columbia waters up to date and to provide for these reclassifications.

First Record of the Dusky Sculpin (Icelinus burchami) in British Columbia Waters

not available

Distribution of Introduced Marine Mollusca in British Columbia Waters

The distribution of a number of species of lamellibranchs and gastropods that have been introduced into British Columbia waters largely as a result of oyster cultural operations is discussed. The dispersal routes and barriers are indicated in relation to known hydrographic conditions and circulation patterns. The problems of spawning, larval movements, metamorphosis, and spat survival are examined.The introduced species that are discussed are Crassostrea gigas, Mya arenaria, Venerupis japonica, Ocenebra japonica, Teredo navalis, Nassarius obsoletus, Purpura clavigera, Urosalpinx cinerea and Batillaria cumingi.

A New Gunnel, Pholis clemensi, from the Coast of Western North America

A new species, Pholis clemensi, referred to the family Pholidae, is named and described from 12 specimens taken in southern British Columbia waters and the Strait of Juan de Fuca. Pholis clemensi is compared with other members of the genus, and a key is given to the North American species.