DOCSLIB.ORG

Pacific Oyster Nocardiosis

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Pacific Oyster Nocardiosis bivalve mollusc Bacteria Pacific Oyster Nocardiosis I. Causative Agent and Disease IV. Transmission Pacific oyster nocardiosis (PON), The bacterium is considered to be an previously known as “focal necrosis” opportunistic pathogen that is widespread and “fatal inflammatory bacteremia” in the marine environment. Transmis- (FIB) is caused by an actinomycete sion is likely horizontal and facilitated by bacterium Nocardia crassostreae that other physical environmental stressors. is Gram-positive or Gram variable, acid fast, PAS positive and catalase positive. V. Diagnosis The bacterium contributes to “summer Histological examination of typical mortality” of 2 year and older oysters in lesions in infected oyster tissues indicate shallow, warm eutrophic embayments Gram-positive or Gram-variable, acid fast during August through November when foci of bacteria within surface vesicles seawater temperature is 20°C or greater. and in granulomas eliciting a marked Infection produces small round yellow, host inflammatory response. Confirma- green or brown vesicles of bacteria and tion is by fluorescent antibody staining granulmoas 2 mm to 1 cm in diameter and by transmission electron microscopy throughout oyster tissues resulting in showing typical actinomycete morpholo- significant mortality. gy. Culture of the organism is possible on several medias for fastidious organisms II. Host Species but is not a routine procedure because the This disease is reported to be appearance of colony growth may take restricted to Pacific oysters, although a from 3 weeks to 3 months. similar disease has been observed in Eu- ropean flat oysters cultivated near areas VI. Prognosis for Host of infected Pacific oysters. PON has been Mortality of infected oysters may be reported in Pacific oysters from Califor- significant but has not been accurately nia, Washington, British Columbia, Japan determined in the field. However, ex- and most recently from the Netherlands. perimental injection of the organism has In Alaska, infection by this organism was produced 47-50% cumulative mortality detected in only two juvenile animals of oysters within 30 days. Management imported from the state of Washington techniques have not been investigated but but had been reared in Alaskan waters. culturing oysters in off-bottom gear and Therefore, it is unclear whether the avoidance of shallow warm embayments disease can spontaneously occur in the in the summer may reduce the prevalence colder seawater temperatures typical of and severity of the disease. Alaskan summers. VII. Human Health Significance III. Clinical Signs Aside from aesthetically displeas- Clinical signs of PON include moder- ing, there are no known zoonotic human ate to high mortality of young adult health concerns with Nocardia infection oysters that are undergoing physiological of Pacific oysters. stress from rapid gonadal development with presenting lesions of small, round, yellow, green or brown vesicles of bacte- ria and granulomas in the tissues. 14 15 bivalve mollusc Bacteria Yellow vesicles (arrow) of nocardiosis Histological section of vesicles containing bac- in the mantle tissues of a Pacific oyster teria (arrow) in infected mantle tissue (Photo: R. Elston, AquaTechnics, WA) Typical subsurface radiating granuloma (arrow) containing central Nocardia organisms sur- ounded by host inflammatory cells, histological section 14 15.
Load more

Recommended publications
  • Olympia Oyster (Ostrea Lurida)
    COSEWIC Assessment and Status Report on the Olympia Oyster Ostrea lurida in Canada SPECIAL CONCERN 2011 COSEWIC status reports are working documents used in assigning the status of wildlife species suspected of being at risk. This report may be cited as follows: COSEWIC. 2011. COSEWIC assessment and status report on the Olympia Oyster Ostrea lurida in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. xi + 56 pp. (www.sararegistry.gc.ca/status/status_e.cfm). Previous report(s): COSEWIC. 2000. COSEWIC assessment and status report on the Olympia Oyster Ostrea conchaphila in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. vii + 30 pp. (www.sararegistry.gc.ca/status/status_e.cfm) Gillespie, G.E. 2000. COSEWIC status report on the Olympia Oyster Ostrea conchaphila in Canada in COSEWIC assessment and update status report on the Olympia Oyster Ostrea conchaphila in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. 1-30 pp. Production note: COSEWIC acknowledges Graham E. Gillespie for writing the provisional status report on the Olympia Oyster, Ostrea lurida, prepared under contract with Environment Canada and Fisheries and Oceans Canada. The contractor’s involvement with the writing of the status report ended with the acceptance of the provisional report. Any modifications to the status report during the subsequent preparation of the 6-month interim and 2-month interim status reports were overseen by Robert Forsyth and Dr. Gerald Mackie, COSEWIC Molluscs Specialist Subcommittee Co-Chair. For additional copies contact: COSEWIC Secretariat c/o Canadian Wildlife Service Environment Canada Ottawa, ON K1A 0H3 Tel.: 819-953-3215 Fax: 819-994-3684 E-mail: COSEWIC/[email protected] http://www.cosewic.gc.ca Également disponible en français sous le titre Ếvaluation et Rapport de situation du COSEPAC sur l’huître plate du Pacifique (Ostrea lurida) au Canada.
    [Show full text]
  • Pierce County Nearshore Species List Compiled from the Pt
    Pierce County Nearshore Species List Compiled from the Pt. Defiance Park Bioblitz 2011 ID COMMON NAME √ ID COMMON NAME √ 31 Acorn barnacle X 34 Hermit crab sp. X 43 Aggregate green anemone X 35 Isopod sp. X 30 Amphipod sp. X 36 Jellyfish sp. X 95 Anemone sp. 73 Large leaf worm X 60 Barnacle nudibranch X 12 Leafy hornmouth X 48 Barnacle sp. X 74 Leather limpet 68 Bent-nose macoma 13 Leather star X 69 Black and white brittle star 14 Lewis's moonsnail X 92 Black turban X 37 Limpet sp. 63 Blood star X 75 Lined chiton X 56 Butter clam X 76 Lined ribbon worm 65 Calcareous tube worm X 108 Mask limpet X 103 California mussel X 67 Moon jellyfish X 1 California sea cucumber 32 Mossy chiton X 53 Checkered periwinkle X 61 Mottled star X 32 Chiton sp. 38 Mussel sp. X 33 Clam sp. X 77 Northern feather duster w X 70 Coonstripe shrimp 15 Northern kelp crab 59 Crab sp. X 39 Nudibranch sp. X 96 Dog welk sp. X 78 Nuttall's cockle 93 Dogwinkle sp. X 62 Ochre star X 3 Dungeness crab X 16 Opalescent (aeolid) nudib X 57 Eccentric sand dollar X 17 Orange sea cucumber X 112 Fat gaper X 18 Orange sea pen 4 Feathery shipworm X 19 Oregon triton 5 Fish-eating anemone 40 Oyster sp. 101 Flat porcelain crab 79 Pacific blue mussel X 6 Fringed tube worm 110 Pacific gaper 8 Giant (nudibranch) dendronotid 99 Pacific geoduck clam X 7 Giant barnacle X 80 Pacific oyster 9 Giant pacific octopus 97 Periwinkle sp.
    [Show full text]
  • The Pacific Oyster – a New Nordic Food Resource and a Basis for Tourism
    Policy Brief The Pacific oyster – a new Nordic food resource and a basis for tourism 1 Policy Brief: The Pacific oyster – a new nordic food resource and a basis for tourism Stein Mortensen, Per Dolmer, Åsa Strand, Lars-Johan Naustvoll and Ane Timenes Laugen Nord 2019:015 ISBN 978-92-893-6121-7 (PRINT) ISBN 978-92-893-6122-4 (PDF) ISBN 978-92-893-6123-1 (EPUB) http://dx.doi.org/10.6027/Nord2019-015 © Nordic Council of Ministers 2019 Layout: Mette Agger Tang Cover photo: Øystein Klakegg Print: Rosendahls Printed in Denmark Nordic co-operation Nordic co-operation is one of the world’s most extensive forms of regional collaboration, involving Denmark, Finland, Iceland, Norway, Sweden, the Faroe Islands, Greenland, and Åland. Nordic co-operation has firm traditions in politics, the economy, and culture. It plays an important role in European and international collaboration, and aims at creating a strong Nordic community in a strong Europe. Nordic co-operation seeks to safeguard Nordic and regional interests and principles in the global community. Shared Nordic values help the region solidify its position as one of the world’s most innovative and competitive. Nordic Council of Ministers Nordens Hus Ved Stranden 18 DK-1061 Copenhagen www.norden.org Download and order Nordic publications from www.norden.org/nordpub 2 Policy Brief The Pacific oyster – a new Nordic food resource and a basis for tourism Content 05 The Pacific oyster – friend or foe? 07 The dispersal of oysters and their environmental effects 08 Mitigation of invasive aquatic species 09 Commercial exploitation of Pacific oysters in Scandinavia 11 Regional oysters – or the meaning of merroir 12 Challenges 14 Conclusions and recommendations 15 Selected literature 4 The Pacific oyster – friend or foe? Since 2007, the Pacific oyster has established self-sustaining po- pulations in Scandinavian coastal waters.
    [Show full text]
  • Drakes Bay Oyster Company 17171 Sir Francis Drake Boulevard Inverness, CA 94937 (415) 669-1149 [email protected] [email protected]
    DOC180 Drakes Bay Oyster Company 17171 Sir Francis Drake Boulevard Inverness, CA 94937 (415) 669-1149 [email protected] [email protected] March 4, 2011 Natalie Gates DBOC SUP EIS Re: New cultured species request Dear Natalie, On January 26, 2011 Cicely Muldoon requested additional scoping information about the native Olympia oysters and the native Purple Hinged Rock Scallops. DBOC has been given a deadline of March 4, 2011 to provide all additional scoping information. This letter will provide additional information regarding native shellfish culture in Drakes Estero. The NPS has already been provided significant information regarding the request to culture native species. Some background regarding this request is necessary. DBOC, following procedures set forth in its special use permit, initiated the process to add native species to its State Fish and Game lease. Section 4(b)(vi) of the DBOC SUP says, in full: “Permittee will not introduce species of shellfish beyond those described in the existing leases from the CDFG. Permittee may seek to conform and/or modify these leases with the CDFG. Any modifications approved by CDFG will be considered by Permitter on a case- by-case basis, and Permittee may not implement any such modifications without the prior written approval of the Permitter.” (emphasis added) Pursuant to this section, DBOC sought to modify the lease with CDFG, understanding that NPS approval would be required before implementation of such modification. On April 27, 2010, before the DBOC SUP EIS was contemplated, DBOC made a request (attachment a) to the California Fish and Game Commission. On June 28, 2010, the NPS wrote a letter (attachment b) to Jim McCamman, Director, California Department of Fish and Game, opposing the DBOC request.
    [Show full text]
  • Alaska Oyster Growers Manual, 4Th Edition
    Alaska Oyster Growers Manual th 4 Edition A resource for new and experienced farmers including recommended culture techniques, explanations of various culture systems, business planning assistance, and a guide to obtaining permits and leases Alaskan Shellfish Growers Association and Alaska Sea Grant Marine Advisory Program, University of Alaska Fairbanks November 2012 The Alaska Oyster Growers Manual is the result of collaboration between the Alaskan Shellfish Growers Association and the Alaska Sea Grant Marine Advisory Program, University of Alaska Fairbanks. Funding was provided by a Rural Business Enterprise Grant obtained by ASGA through the USDA Rural Development Alaska office. Copies of this document are available at the Alaska Sea Grant bookstore: http://seagrant.uaf.edu/bookstore/pubs/AN-19.html Or contact Raymond RaLonde, 907-274-9697, [email protected] This manual is dedicated to Art King for his tireless efforts to help shellfish farming in Alaska grow. King (left) helps ASGA president Rodger Painter (center) and Ray RaLonde, of the Alaska Sea Grant Marine Advisory Program, shuck purple-hinged rock scallops for a research project. CONTENTS 1. INTRODUCTION BASIC BIOLOGY OF THE PACIFIC OYSTER 2. Biology of the Pacific Oyster in Alaska: Classification and Anatomy 3. Biology of the Pacific Oyster in Alaska: Feeding and Nutrition 4. Biology of the Pacific Oyster in Alaska: Life History and Growth COOPERATION AND COOPERATIVES 5. Why Cooperate? 6. Best Management Practices for Shellfish Cooperatives SITE SELECTION 7. Site Selection Is a Business Decision 8. How to Select an Oyster Farm Site in Alaska CULTURE SYSTEMS 9. Evolution of Oyster Culture Methods in Alaska 10.
    [Show full text]
  • Age and Growth of Wild Suminoe (Crassostrea Ariakensis, Fugita 1913) and Pacific (C
    AGE AND GROWTH OF WILD SUMINOE (CRASSOSTREA ARIAKENSIS, FUGITA 1913) AND PACIFIC (C. GIGAS, THUNBERG 1793) OYSTERS FROM LAIZHOU BAY, CHINA Author(s): JULIANA M. HARDING and ROGER MANN Source: Journal of Shellfish Research, 25(1):73-82. Published By: National Shellfisheries Association DOI: http://dx.doi.org/10.2983/0730-8000(2006)25[73:AAGOWS]2.0.CO;2 URL: http://www.bioone.org/doi/full/10.2983/0730-8000%282006%2925%5B73%3AAAGOWS %5D2.0.CO%3B2 BioOne (www.bioone.org) is a nonprofit, online aggregation of core research in the biological, ecological, and environmental sciences. BioOne provides a sustainable online platform for over 170 journals and books published by nonprofit societies, associations, museums, institutions, and presses. Your use of this PDF, the BioOne Web site, and all posted and associated content indicates your acceptance of BioOne’s Terms of Use, available at www.bioone.org/page/terms_of_use. Usage of BioOne content is strictly limited to personal, educational, and non-commercial use. Commercial inquiries or rights and permissions requests should be directed to the individual publisher as copyright holder. BioOne sees sustainable scholarly publishing as an inherently collaborative enterprise connecting authors, nonprofit publishers, academic institutions, research libraries, and research funders in the common goal of maximizing access to critical research. Journal of Shellfish Research, Vol. 25, No. 1, 73–82, 2006. AGE AND GROWTH OF WILD SUMINOE (CRASSOSTREA ARIAKENSIS, FUGITA 1913) AND PACIFIC (C. GIGAS, THUNBERG 1793) OYSTERS FROM LAIZHOU BAY, CHINA JULIANA M. HARDING* AND ROGER MANN Department of Fisheries Science, Virginia Institute of Marine Science, College of William and Mary, P.O.
    [Show full text]
  • The Immigrant Oyster (Ostrea Gigas)
    THE IMMIGRANT OYSTER (OSTREA GIGAS) NOW KNOWN AS THE PACIFIC OYSTER by E. N. STEELE PIONEER OLYMPIA OYSTERMAN IN COOPERATION WITH PACIFIC COAST OYSTER GROWERS ASSOCIATION, INC. TABLE OF CONTENTS CHAPTER I.........................................................................................................................Page 1 INTRODUCTION AN OYSTER GOES ABROAD SEED SETTING IN MAYAGI PREFECTURE IN YEAR 1918 SEEDS WERE VERY SMALL IN YEAR 1919 STORY OF JOE MAYAGI AND EMY TSUKIMATO SAMISH BAY SELECTED FOR EXPERIMENTAL PLANTINGS FIRST PLANTING OF SEED WAS A SUCCESS EXPERIMENTAL WORK IN JAPAN REPORT BY DR. GALTSOFF (Doc. 1066) U. S. BIOLOGIST Dr. HORI, JAPANESE BIOLOGIST OFFICIAL) REPORT ON SEED IN 1919 LESSONS LEARNED FROM JAPANESE EXPERIENCE Time of year to ship--Small seed most successful- When and where planted required further experience -The oyster had to answer that question. A TRIP TO SAMISH BAY WASHINGTON STATE PASSED ANTI-ALIEN ACT IN 1921 ROCKPOINT OYSTER Co. COMPLETED PURCHASE MAY 18, 1923 CHAPTER II........................................................................................................................Page8 An Oyster becomes Naturalized-Haines Oyster Co. of Seattle First Customer -Development of Seattle Markets -First year marketing very limited -First year shipper, Emy Tsukimato from Japan -First Seed Shipment, 492 Cases. Samples still retained. Development of best type of cultch. Experimental shipping in hold of ship or on deck -expanding the markets. Advent of planting in Willapa Harbor and Grays Harbor -
    [Show full text]
  • Southern California Tidepool Organisms
    Southern California Tidepool Organisms Bryozoans – colonial moss animals Cnidarians – stinging invertebrates Derby Hat Bryozoan Red Bryozoan Aggregating Anemone Giant Green Anemone Sunburst Anemone Eurystomella spp. Watersipora spp. Anthopleura elegantissima Anthopleura xanthogrammica Anthopleura sola closed closed closed open 2 in (5 cm) open 6.7 in (17 cm) open 6.5 in (12cm) Echinoderms – spiny-skinned invertebrates Sea Stars note signs of wasting Bat Star Brittle Star Ochre Star Giant Pink Sea Star Six Armed Sea Star Sunflower Star Patiria miniata (various genuses) Pisaster ochraceus Pisaster brevispinus Leptasterias spp. Pycnopodia helianthoides Purple or Red webbed arms 10 in 11 in 31.5 in Various sizes 4.7 in (12 cm) Long, thin arms (25 cm) (28 cm) 6 arms, 2.4 in(6 cm) (80 cm) Sand Dollar Sea Cucumbers Urchins note signs of balding Eccentric Sand Dollar California Sea Cucumber Warty Sea Cucumber Purple Urchins Red Urchins Dendraster excentricus Parastichopus californicus Parastichopus parvimensis Strongylocentrotus Strongylocentrotus purpuratus franciscanus has small 4 in 7in black tipped warts (10 cm) (17 cm) 4 in (10 cm) 16 in (40 cm) 10 in (25 cm) long (projections) Mollusks – soft invertebrates with a shell or remnant shell Snails (single, spiraled shelled invertebrate) Turban Snail Periwinkle Snail Kellet’s Whelk Snail Dog Whelk Snail Unicorn Whelk Snail Scaly Tube Snail Tegula spp. Littorina spp. Kelletia kelletii (Dogwinkles) Acanthinucella spp. Serpulorbis squamigerus Nucella spp. Top view 6 ½ in 2 in 1.6 in (16.5 cm) (5 cm) 1 in (2.5 cm) ½ in (1.5 cm) (4cm) 5 in (13 cm) Bi-Valves (2 shelled invertebrates) Abalone California Mussel Blue Mussel Olympia Oyster Pacific Oyster Rock Scallop Haliotis spp.
    [Show full text]
  • Live Oysters
    LIVE OYSTERS West Coast There are an infinite number of names and harvest locations for these oysters. They are all the same species with only two exceptions. The species that are cultured on the West Coast are: Crassostrea gigas - Originated from Japan Crassostrea sikameo - Kumamoto, really a sub species of gigas Ostrea lurida - Olympia The gigas is a Pacific oyster indigenous to Japan that is widely grown in California and the Pacific Northwest. Different names are used to describe where the oysters were harvested. Generally it is a bay, beach, island or canal. The Kumamoto is a sub species of the gigas and is raised from British Columbia to Mexico. Most oyster connoisseurs recognize the Washington and Oregon Kumamoto as the true Kumamoto. The Kumamotos from this area tend to be the smaller, sweeter variety that is familiar to most people. The California Kumamoto is also nice but is a bit larger in size. Technically the California Kumamoto is a hybrid between a gigas and a Kumamoto. The mortality rate of the seed/spat of a Kumamoto is very high, thus yields in the oyster beds are never as high as the grower would like. Therefore, they tend to be less available and more expensive. This may be one of the reasons that the hybrid Kumamoto was developed, to have a stronger oyster that survived better and could be produced in larger quantities. All but one west coast oyster falls into the first category of gigas. The exception is the Olympia. The Olympia is the only indigenous oyster to the west coast.
    [Show full text]
  • Growing Shellfish in Alaska
    MARINE ADVISORY PROGRAM UNIVERSITY OF ALASKA Vol. VII No. 4 December 1992 In This Issue: Growing Shellfish in Alaska f Pacific Oysters Shellfish Aquaculture in Alaska: Its Promise and Constraints Locations If you hope to succeed in the growing Alaskan shellfish industry, a good s understanding of what is involved is required. Marine Advisory aquaculture atat ngton State specialist, Ray RaLonde, describes some of the history and the culture pro- British Columbia Jun April November Prince William Sound June April cess for a variety of species that are possible in Alaska. .2 Select species to Aquatic Farm Permits culture Select potential site(s) Site survey(s) Prior to 1988 aquatic farm permitting was a confusing and lengthy ordeal. Yes No DNR site Possible problems Aquatic farm Aquatic farm permit suitablity appl. with site application opening application No Yes ADF&G transport No COE permit Floating or permit appl. required submersed structure Regulations were often unclear or non-existent. But with passage of the One year site Uplands required? trials Site trials Yes positive aquatic farm act, permit processing became formalized. However, for many No Submit To DNR: (during 60 day application period) 1) Aquatic farm application 2) Coastal project questionnaire 3) Federal applications (copies) Special area Permit (To DFG) Include in aquatic farm application people the process is still difficult to understand. Mariculture coordinator Agency review Additional information request for the Alaska Department of Fish and Game, Jim Cochran, explains what ACMP dii you need to know to get started. 6 Commercial Oyster Farming: Part of Students Training In 1989 Petersburg high school instructor, Jack Eddy, conducted shellfish and plankton research in his area with the hopes of establishing a school aquaculture program.
    [Show full text]
  • Ostrea Edulis) (Crassostrea Gigas)
    Large-scale Pacific oyster removal experiment in the Oosterschelde (The Netherlands) Jeroen Wijsman1 & Aad Smaal2 1Wageningen Marine Research 2Aquaculture & Fisheries Group, Wageningen University & HZ University of Applied Sciences 2 Oosterschelde • 341 km2 • 104 km2 intertidal area • Nature conservation area • Shellfish culture 3 Shellfish culture, mainly bottom culture • Mussels (25 Mkg yr-1) • Pacific oysters (3 Mkg yr-1) • Flat oysters (0.25 Mkg yr-1) Flat oyster Pacific oyster (Ostrea edulis) (Crassostrea gigas) 4 Pacific oysters • Traditional culture since 1870 flat oyster (Ostrea edulis) • Susceptible to Bonamia ostrea 1000 • Mass mortality after severe winter 1962/1963 800 • Pacific oysters introduced in 1964 • Plans to make Oosterschelde freshwater lake 600 • Oosterschelde too cold for reproduction 400 • 1971 fist observed in the wild (ha) Area 200 0 1970 1980 1990 2000 2010 Year 5 Development oyster reefs 5 km 1980:2005:1990: 15766212 ha ha 6 WARNING Take care of oyster shells with sharp edges. They can Impact pacific oysters cause deep cuttings • Competition with mussels and cockles for food and space • Not a good food source for birds • Growth on sluices and dykes Grazing pressure (Mm3 d-1) • Recreation 7 Large-scale removal of oysters (2006) • 4 experimental plots (12.5 ha each) • 2 littoral and 2 sublittoral • Dumped at 2 locations 8 Location Zandkreek 9 Location Vondelingsplaat 10 Fishing with mussel dredges • Dutch mussel farmers 11 Effort • 1000 boat hours 70000 • 20 boat hours per ha 60000 ) 50000 1 • Costs ca €300 000
    [Show full text]
  • Quantifying Abundance and Distribution of Native and Invasive Oysters in an Urbanised Estuary
    Aquatic Invasions (2016) Volume 11, Issue 4: 425–436 DOI: http://dx.doi.org/10.3391/ai.2016.11.4.07 Open Access © 2016 The Author(s). Journal compilation © 2016 REABIC Research Article Quantifying abundance and distribution of native and invasive oysters in an urbanised estuary Elliot Scanes1,2,*, Emma L. Johnston3,4, Victoria J. Cole1,2, Wayne A. O’Connor5, Laura M. Parker1 and Pauline M. Ross1,2 1School of Life and Environmental Sciences, Coastal and Marine Ecosystems Group, The University of Sydney, Sydney, NSW 2006, Australia 2 School of Science and Health, Western Sydney University, Penrith, Sydney NSW 2750, Australia 3School of Biological, Earth and Environmental Sciences, Evolution and Ecology Research Centre, The University of New South Wales, Sydney, NSW 2052, Australia 4Sydney Institute of Marine Science, Mosman, NSW 2088, Australia 5New South Wales Department of Primary Industries, Port Stephens Fisheries Institute, Taylors Beach, NSW 2316, Australia *Corresponding author E-mail: [email protected] Received: 9 January 2016 / Accepted: 2 August 2016 / Published online: 25 August 2016 Handling editor: Darren Yeo Abstract Human activities have modified the chemical, physical and biological attributes of many of the world’s estuaries. Natural foreshores have been replaced by artificial habitats and non-indigenous species have been introduced by shipping, aquaculture, and as ornamental pets. In south east Australia, the native Sydney rock oyster Saccostrea glomerata is threatened by pollution, disease and competition from the invasive Pacific oyster Crassostrea gigas. This study assessed the abundance (as number m-2), size, and distribution of both invasive and native oyster species at 32 sites in the heavily urbanised Port Jackson Estuary, Australia.
    [Show full text]