Occurrence of Pollock,Pollachius virens, and Sand Lance,Ammodytessp., Larvae in the Bay of Fundy
01 Dec 1980-Journal of Northwest Atlantic Fishery Science (Northwest Atlantic Fisheries Organization (NAFO))-Vol. 1, pp 45-48
TL;DR: A plankton survey of the Bay of Fundy in March 1979 revealed for the first time the occurrence of pollock and sand lance larvae.
Abstract: A plankton survey of the Bay of Fundy in March 1979 revealed for the first time the occurrence of pollock and sand lance larvae. Distributions of numbers per tow and length composition of catches indicated that the pollock larvae originated outside the Bay and dispersed from the south toward the inner part of the Bay. Similar data for sand lance indicated two spawning areas, one near Cape Chignecto from which the larvae dispersed toward the mouth of the Bay, and the other near Long Island, western Nova Scotia. with apparent mixing at the mouth of the Bay of larvae from both spawning sites.
01 Jan 2000
TL;DR: Sand lance constitute a major prey for at least some populations of over 100 species of consumer, including 40 species of birds, 12 species of marine mammals, 45 species of fishes, and some invertebrates.
Abstract: Robards, Martin D.; Willson, Mary F.; Armstrong, Robert H.; Piatt, John F., eds. 1999. Sand lance: a review of biology and predator relations and annotated bibliography. Res. Pap. PNW-RP-521. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 327 p. Six species of sand lance (Ammodytes) in temperate and boreal regions are currently recognized. Sand lance can occupy a wide range of environmental conditions, but all appear to be dormant predominantly in winter, and one species is in summer also. They lack a swim bladder and spend much of their time buried in specific substrates. Copepods are the primary food. Spawning usually occurs in fall or winter (although some species also spawn in spring), eggs are demersal, and larvae may hatch at times of low food abundance. Sand lance usually occur in schools and are regarded as a relatively high-quality forage fish. Sand lance constitute a major prey for at least some populations of over 100 species of consumer, including 40 species of birds, 12 species of marine mammals, 45 species of fishes, and some invertebrates. Variation in the availability of sand lance (and other forage fishes) can have major effects on the breeding success and survival of their predators. Commercial fishing and other pressures on sand lance populations potentially have ramifying effects on many species of wildlife. The bibliography contains over 1,700 references on the family Ammodytidae, with an emphasis on the genus Ammodytes.
TL;DR: Tagged inshore pollock were observed to grow 17-18 cm during their first year of life, an annual instantaneous growth rate of4.1, and 27-30 cm by the end of their second year (G =1.8).
Abstract: Data collected from tagging studies along the coast of Nova Scotia and offshore ichthyoplankton surveys were used to investigate growth and inshore-offshore migrations of juvenile pollock. Age zero pollock from 0.3 to 4.2 cm in length were found in the offshore plankton between November and June and small pollock at lengths of 7-11 cm were caught inshore in July. These small pollock appear to have moved inshore after leaving the offshore pelagic community at 3-6 months of age. They remain inshore until they reach approximately 30+ cm during their second year. Tagged inshore pollock were observed to grow 17-18 cm during their first year of life, an annual instantaneous growth rate (G) of4.1, and 27-30 cm by the end of their second year (G =1.8). Seasonal variability in growth was also observed in juvenile pollock. Mean absolute growth from May until August was 1.75 cm per month, from August until October 1.50 cm per month, and from November until April about 0.5 cm per month. A tagging related mortality experiment using winter tagged juveniles indicated a 11% mortality during the first 3 months after tagging.
TL;DR: In this paper, the authors conclude that the Port Moller sand lance stock has an estuarine early life history that evolved in response to the unique physical conditions of the port Moller estuary, a shallow, well-mixed site with sandy substrate that is suitable for incubation of demersal eggs next to a deep, vertically stratified fjord with a rich zooplankton community.
Abstract: Three waves of spawning Pacific sand lance (Ammo-dytes hexapterus) entered the Port Moller estuary from mid-January to late May 1990 Each wave laid its eggs on sand in lower Moller Bay with the center of egg distribution about 14 km inside the estuary After incubation for 45 to 94 d, each cohort of eggs hatched out over a 41- to 63-d period Larvae moved at a rate of 021 knvd“1 toward a deep fjordlike basin at the head of Herendeen Bay inside the estuary about 20 km southwest of the center of hatch The basin has the lowest flushing rate of the estuary, and unlike the rest of Port Moller, it is vertically stratified, which allows the development of a spring-summer zooplankton community with greater biomass than any other location in the estuary Larvae may have moved to the basin to enhance growth or to avoid offshore transport to areas of low food abundance, but we cannot demonstrate a direct link between growth and habitat We conclude that the Port Moller sand lance stock has an estuarine early life history that evolved in response to the unique physical conditions of the Port Moller estuary–a shallow, well-mixed site with sandy substrate that is suitable for incubation of demersal eggs next to a deep, vertically stratified fjord with a rich zooplankton community that is suitable for rearing of larvae
TL;DR: In this paper, the distribution of pollock eggs and larvae also indicates the presence of several spawning sites on the Scotian Shelf in addition to previously documented locations in the western Gulf of Maine.
Abstract: Commercial exploitation of pollock in NAFO Divisions 4VWX and Subareas 5 and 6 has increased considerably over the past two decades as abundance of traditional groundfish species has declined. Total pollock landings from this area increased from less than 30,000 (metric) tons per year during the late-1960s to over 60,000 tons since 1985; USA recreational catches have contributed between 1,000 and 2,000 tons to the annual totals. Since 1977, when both the USA and Canada extended uni-Iateral jurisdiction over their fishery resources to 200 miles, domestic management programs for pollock have been either non-existent or ineffective in restricting total landings. Assessment and management advice for pollock has traditionally been predicated on the assumption of a single unit stock within the region. Tagging studies and morphometric and meristic measurements, however, suggest a possible separation of Gulf of Maine pollock from those on Browns Bank and Emerald Basin on the Scotian Shelf. The distribution of pollock eggs and larvae also indicates the presence of several spawning sites on the Scotian Shelf in addition to previously documented locations in the western Gulf of Maine. Sexual maturation and growth rates for pollock are similar throughout the region. Growth rates of males and females do not differ significantly, although the median size at maturity is slightly larger for males. The majority of pollock of both sexes become sexually mature during their third year. Recruitment has been consistent since the late-1960s with one or more relatively strong year-classes appearing throughout the region every 3-4 years. Pollock become fully recruited to the fishery between ages 6 and 7, although partial recruitment declines again after age 7. Estimates of total stock size (age 2+), derived from virtual population analysis (VPA), increased from 102 million fish in 1974 to 145 million in 1977, but declined to 97 million in 1980. Following recruitment of the 1979 year-class at age 2 in 1981, stock size increased to 168 million before declining to 113 million in 1988. Instantaneous fishing mortality (F) has exceeded Fo.i (0.29) but remained at or below Fm a, (0.57) throughout the 1970s. Fishing mortality has been close to Fm a" however, in 4 of the 6 years since 1982. Analyses of research vessel survey data generally agree with results obtained from the VPA, indicating a recent decline in stock abundance and biomass, and an increase in instantaneous total mortality. Equilibrium calculations suggest that fishing at Fa' would provide a long-term yield of 53,600 tons from a stock biomass of 317,700 tons, while fishing at Fm a, would provide a yield of 58,100 tons from a stock biomass of 204,600 tons. Corresponding spawning stock biomass levels at Fa' and Fm a, are 260,400 and 149,800 tons respectively. Although long-term yields are approximately 8% greater at the Fm a, level, fishing at Fa' provides for a 55% increase in total stock and 74% increase in spawning stock biomass over those allowed under Fma, . 'Present address: Max Planck Institute, 1A Marconi Strasse, Julich D-5170, Federal Republic of Germany. 14 J. Northw. Atl. Fish. Sci., Vol. 9,1989
01 Jan 2014
TL;DR: The life stage USAGE of ESTUARINE/MarINE/MARINE HABITAT has been studied in this article, with a focus on Atlantic Salmon Marine Habitat.
Abstract: iv RESUME v INTRODUCTION 1 CONTEXT 1 BACKGROUND 2 REGULARLY FREQUENTED MARINE HABITAT 2 THE GULF OF MAINE 4 Circulation Patterns 4 BAY OF FUNDY 4 Geomorphology 4 Surface Currents 5 Tides 6 Salinity 6 Temperature 7 Productivity 7 Prey of Atlantic Salmon 7 FRESHWATER AREAS OF CRITICAL HABITAT 9 ESTUARINE AND MARINE AREAS OF OCCUPANCY 9 SMOLT 9 POST-SMOLTS 10 Historical Tagging: 1963-1990 10 First Electronic Tagging Study: 1999 11 Second Electronic Tagging Study: 2001-2002 13 Trawling Surveys: 2001-2003 15 MATURING AND NON-MATURING SALMON 17 RETURNING ADULTS 17 Bay of Fundy Commercial/Salmon Fisheries 18 Inner Bay of Fundy in-River Recreational Fisheries 20 KELTS 21 SUMMARY: LIFE STAGE USAGE OF ESTUARINE/MARINE HABITAT 22 Smolts 22 Post-Smolts 23 Maturing/Non-Maturing Salmon 24 Returning Adults 24 Kelts 25 PROPOSAL FOR IMPORTANT HABITAT 25 RESEARCH RECOMMENDATIONS 26 ADDITIONAL RESEARCH 29 ADDITIONAL CONSIDERATIONS 29 ACKNOWLEDGEMENTS 29 LITERATURE CITED 30 TABLES 37 FIGURES 42 ANNEX 1 67 Maritimes Region iBoF Atlantic Salmon Marine Habitat
01 Jan 1925
TL;DR: The first part of the general report, dealing with the fishes was published in 1925, as Bulletin of the United States Bureau of FisherIes, and subsequent parts describing the plankton of the offshore waters of the Gulf and the physical Characteristics of its waters were published in 1926-27, as Part 2. as discussed by the authors.
Abstract: During the summer of 1912 the Bureau of Fisheries with the cooperation of the Museum of Com;arative Zoology of Harvard Un~vers~ty, cOInInenced an oceanographic and bIOlogIcal survey of the Gulf of Maine, with special reference to its fishes to its floating plants and animals (Plankton), to the physical and chemical state of its waters and to the circulation of the latter. Cruises ;ere made on the Fisheries schooner Grampu8 during the summers and autumns of 1912, 1913, 1914, 1915 and 1916, and during the winters and springs of 1913 and 1915. The work Was interrupted by the war, but was resumed with a cruise of the Fisheries steamer Albatross in the late winter and spring of 1920, and was continued by the Fisheries steamer Halcyon during the winter and spring of 1920-21, and the summers of 1921 and 1922. The first part of the general report, dealing with the fishes was published in 1925, as Bulletin ~o (Pt. 1) of the United States Bureau of FisherIes; 1 SUbsequent parts describing the plankton of the offshore waters of the Gulf and the physical Characteristics of its waters were published in 1926-27, as Part 2. The preparation of the section on the fishes was assigned originally to W. W. Welsh, who had gathered a large body of original observations on the growth, reproduction, diet, and other phases of the lives of many of the more important species. The report was far advanced when it was interrupted by his untimely death, and H. B. Bigelow ~dertook to carry it to publication along the Imes originally laid down. The new edition, entailing a general revision and the addition of In'Uch new lnaterial, has been prepared jointly by !: B. Bigelow and by W. C. Schroeder.
01 Jan 1977
TL;DR: The largest landings of pollock in the western Atlantic were made in this area (ICNAF Division 4X) and the best catches of large fish are made at temperatures above 1.1 °C, at depths of 20-100 fathoms (35-185 m) on the edges of shoals and banks where food is abundant as discussed by the authors.
Abstract: Observations made on the biology of the pollock in the western Atlantic, and primarily in the Bay of Fundy region of the northern Gulf of Maine, are presented. The largest landings of pollock in the western Atlantic are made in this area (ICNAF Division 4X). The best catches of large fish are made at temperatures above 1.1 °C, at depths of 20–100 fathoms (35–185 m) on the edges of shoals and banks where food is abundant. Spawning occurs in the winter and takes place in the southern Gulf of Maine and probably also on the Scotian Shelf, but not in the northern Gulf of Maine. The Bay of Fundy pollock are recruited from spawning in the southern Gulf of Maine and possibly on the Scotian Shelf. The pollock found in the Bay of Fundy appear to remain separate from those of the southern Gulf of Maine and the Scotian Shelf in the summer, but migrate south, spawn and probably mix with those of the southern Gulf of Maine, and possibly also those of the Scotian Shelf in the winter. The offshore pollock have a regular ...