DOCSLIB.ORG

The Cryptic and Transboundary Nature of Ghost Gear in the Maldivian Archipelago

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
The Cryptic and Transboundary Nature of Ghost Gear in the Maldivian Archipelago The cryptic and transboundary nature of ghost gear in the Maldivian Archipelago Item Type Thesis or dissertation Authors Stelfox, Martin Citation Stelfox, M. (2019). 'The cryptic and transboundary nature of ghost gear in the Maldivian archipelago'. Unpublished PhD Thesis. Derby: University of Derby. Publisher University of Derby Rights Attribution-NonCommercial-ShareAlike 4.0 International Download date 06/10/2021 14:39:16 Item License http://creativecommons.org/licenses/by-nc-sa/4.0/ Link to Item http://hdl.handle.net/10545/625352 UNIVERSITY OF DERBY The cryptic and transboundary nature of ghost gear in the Maldivian Archipelago Martin Richard Stelfox Doctor of Philosophy 2020 1 Sensitivity: Internal THIS PAGE HAS BEEN INTENTIONALLY LEFT BLANK 2 Sensitivity: Internal Contents Appendices ................................................................................................................................. 6 Figures........................................................................................................................................ 7 Tables ......................................................................................................................................... 9 Abbreviations ........................................................................................................................... 10 Abstract .................................................................................................................................... 12 Preface...................................................................................................................................... 14 Acknowledgements .................................................................................................................. 17 General Introduction ................................................................................................................ 19 Chapter 1: A review of ghost gear entanglement amongst marine mammals, reptiles and elasmobranchs .......................................................................................................................... 27 1.1 Abstract .................................................................................................................................... 28 1.2 Introduction ............................................................................................................................. 28 1.2.1 Supply and demand – A brief look at global fishing pressure ............................................. 29 1.2.2 When does fishing gear become ALDFG ............................................................................ 30 1.2.3 What factors affect ghost fishing rates ................................................................................ 30 1.2.4 The cyclical nature of ghost fishing and the role of bio-fouling .......................................... 32 1.3 Material and Method............................................................................................................... 34 1.4 Results ...................................................................................................................................... 35 1.4.1 The effects of ghost fishing on marine mammals, reptiles and elasmobranchs ................... 35 1.4.2 Gear types........................................................................................................................... 43 1.4.3 Bias in results ..................................................................................................................... 43 1.5 Discussion ................................................................................................................................. 47 1.5.1 Cetaceans and ghost fishings .............................................................................................. 47 1.5.2 Pinnipeds and ghost fishing ................................................................................................ 48 1.5.3 Manatee and dugong and ghost fishing .............................................................................. 49 1.5.4 Marine turtles and ghost fishing ......................................................................................... 49 1.5.5 Elasmobranchs and ghost fishing ....................................................................................... 51 1.5.6 Management and mitigation ............................................................................................... 52 1.6 Conclusion ................................................................................................................................ 54 Chapter 2: Statistical approaches to understanding the source and impact of ghost gear entanglement of Lepidochelys olivacea in the Maldivian Archipelago ............................... 73 3 Sensitivity: Internal 2.1 Abstract .................................................................................................................................... 74 2.2 Introduction ............................................................................................................................. 75 2.3 Material and method ............................................................................................................... 78 2.3.1 Logistic regrression ............................................................................................................ 80 2.3.2 Building classifiers with rare events ................................................................................... 81 2.3.3 Dealing with rare events ..................................................................................................... 82 2.3.4 Assigning fishing nets to fisheries ....................................................................................... 83 2.4 Results ...................................................................................................................................... 84 2.4.1 Logistic regression ............................................................................................................. 85 2.4.2 Random forest model predictions ....................................................................................... 87 2.4.3 Ghost net clustering ............................................................................................................ 89 2.5 Discussion ................................................................................................................................. 91 2.5.1 Causes of turtle entanglement ............................................................................................. 91 2.5.2 Impact on sea turtles ........................................................................................................... 93 2.5.3 Potential origin of nets ....................................................................................................... 95 2.5.4 Solutions and mitigation: Gear traceability ........................................................................ 97 2.5.5 Solutions and mitigation: Ghost net prevention .................................................................. 98 2.6 Conclusion ................................................................................................................................ 99 Chapter 3: Minimum drift times infer trajectories of ghost nets found ............................... 120 3.1Abstract ................................................................................................................................... 121 3.2 Introduction ........................................................................................................................... 122 3.3 Materials and method ........................................................................................................... 125 3.3.1 Study Site .......................................................................................................................... 125 3.3.2 Experimental assessment of bioaccumilation on floating nets and buoys ......................... 126 3.3.3 Ghost net data................................................................................................................... 129 3.3.4 Lagrangian modelling ...................................................................................................... 129 3.3.5 Fishery interaction ........................................................................................................... 130 3.4 Results .................................................................................................................................... 130 3.4.1 Experimental assessment of bioaccumilation on floating nets and buoys ......................... 130 3.4.2 Ghost net age estimates and their putative origin ............................................................. 138 3.4.3 Putative origin for ghost nets without drift time estimates ................................................ 140 3.4. Possible fisheries responsible for ghost nets in the Maldives ............................................. 143 3.5 Discussion ............................................................................................................................... 146 3.5.1 Biofouling communities and ghost gear ageing ................................................................ 146 3.5.2 Lagrangian simulations .................................................................................................... 148 3.5.3
Load more

Recommended publications
  • Stone Tidal Weirs, Underwater Cultural Heritage Or Not? Akifumi
    Stone Tidal Weirs, Underwater Cultural Heritage or Not? Akifumi Iwabuchi Tokyo University of Marine Science and Technology, Tokyo, Japan, 135-8533 Email: [email protected] Abstract The stone tidal weir is a kind of fish trap, made of numerous rocks or reef limestones, which extends along the shoreline on a colossal scale in semicircular, half-quadrilateral, or almost linear shape. At the flood tide these weirs are submerged beneath the sea, while they emerge into full view at the ebb. Using with nets or tridents, fishermen, inside the weirs at low tides, catch fish that fails to escape because of the stone walls. They could be observed in the Pacific or the Yap Islands, in the Indian Ocean or the east African coast, and in the Atlantic or Oleron and Ré Islands. The UNESCO’s 2001 Convention regards this weir as underwater cultural heritage, because it has been partially or totally under water, periodically or continuously, for at least 100 years; stone tidal weirs have been built in France since the 11th century and a historical record notes that one weir in the Ryukyu Islands was built in the 17th century. In Japan every weir is considered not to be buried cultural property or cultural heritage investigated by archaeologists, but to be folk cultural asset studied by anthropologists, according to its domestic law for the protection of cultural properties. Even now in many countries stone tidal weirs are continuously built or restored by locals. Owing to the contemporary trait, it is not easy to preserve them under the name of underwater cultural heritage.
    [Show full text]
  • What Are Trap Nets?
    WHAT ARE TRAP NETS? HOW TO AVOID TRAP NETS Trap nets are large commercial fishing nets used by n Look for red, orange or black flag markers, buoys licensed commercial fisherman to catch fish in the HOW TO IDENTIFY TRAP NETS and floats marking the nets. Great Lakes. With many components, these stationary Some anglers mark the n Trap nets are generally fished perpendicular to the n Give wide berth when passing trap net buoys nets can pose a potential risk to recreational boaters lead end, anchor end or and flag markers, as nets have many anchor lines and anglers. The following facts will help anglers and shoreline (from shallow to deep water). A flag buoy or both ends with a double float marks the lead end of a trap net (closest to shore) flag. Pennsylvania uses the extending in all directions. boaters recognize and avoid trap nets on the open double flag. water. and the main anchor end (lakeward). n Do not pass or troll between trap net buoys, as n Red, orange or black flags attached to a staff buoy at the propeller blades and/or fishing gear may easily pot must be at least 4 feet above the surface of the water. Flags will be approximately 12 inches snag net lines. HOW DO square and bear the license number of the commercial fishing operation. Be aware! During rough water or heavy currents, these flags can lay down or be obscured by high waves. TRAP NETS IF TANGLED IN A TRAP NET n Floats may also mark the ends of the wings and/or each anchor.
    [Show full text]
  • Code of Colorado Regulations 1 H
    DEPARTMENT OF NATURAL RESOURCES Division of Wildlife CHAPTER W-1 - FISHING 2 CCR 406-1 [Editor’s Notes follow the text of the rules at the end of this CCR Document.] _________________________________________________________________________ ARTICLE I - GENERAL PROVISIONS #100 – DEFINITIONS See also 33-1-102, C.R.S and Chapter 0 of these regulations for other applicable definitions. A. "Artificial flies and lures" means devices made entirely of, or a combination of, natural or synthetic non-edible, non-scented (regardless if the scent is added in the manufacturing process or applied afterward), materials such as wood, plastic, silicone, rubber, epoxy, glass, hair, metal, feathers, or fiber, designed to attract fish. This definition does not include anything defined as bait in #100.B below. B. "Bait" means any hand-moldable material designed to attract fish by the sense of taste or smell; those devices to which scents or smell attractants have been added or externally applied (regardless if the scent is added in the manufacturing process or applied afterward); scented manufactured fish eggs and traditional organic baits, including but not limited to worms, grubs, crickets, leeches, dough baits or stink baits, insects, crayfish, human food, fish, fish parts or fis h eggs. C. "Chumming" means placing fish, parts of fish, or other material upon which fish might feed in the waters of this state for the purpose of attracting fish to a particular area in order that they might be taken, but such term shall not include fishing with baited hooks or live traps. D. “Game fish” means all species of fish except unregulated species, prohibited nongame, endangered and threatened species, which currently exist or may be introduced into the state and which are classified as game fish by the Commission.
    [Show full text]
  • Wulik-Kivalina Rivers Study
    Volume 19 Study G-I-P STATE OF ALASKA Jay S. Hammond, Governor Annual Performance Report for INVENTORY AND CATALOGING OF SPORT FISH AND SPORT FISH WATERS OF WESTERN ALASKA Kenneth T. AZt ALASKA DEPARTMENT OF FISH AND GAME RonaZd 0. Skoog, Commissioner SPORT FISH DIVISION Rupert E. Andrews, Director Section C Job No. G-I-H (continued) Page No. Obj ectives Techniques Used F Results Sport Fish Stocking Test Netting Upper Cook Inlet-Anchorage-West Side Susitna Chinook Salmon Escapement Eulachon Investigations Deshka River Coho Creel Census Eshamy-Western Prince William Sound Rearing Coho and Chinook Salmon Studies Rabideux Creek Montana Creek Discussion Literature Cited Section D Study No. G-I Inventory and Cataloging NO. G-I-N Inventory and Cataloging of Gary A. Pearse Interior Waters with Emphasis on the Upper Yukon and the Haul Road Areas Abstract Background Recommendations Objectives Techniques Used Findings Lake Surveys Survey Summaries of Remote Waters Literature Cited NO. G-I-P Inventory and Cataloging of Kenneth T. Alt Sport Fish and Sport Fish Waters of Western Alaska Abstract Recommendations Objectives Background Techniques Used Findings Fish Species Encountered Section D Job No. G- I-P (continued) Page No. Area Angler Utilization Study Life History Studies of Grayling and Arctic Char in Waters of the Area Arctic Char Grayling Noatak River Drainage Survey Lakes Streams Life History Data on Fishes Collected During 1977 Noatak Survey Lake Trout Northern Pike Least Cisco Arctic Char Grayling Round Whitefish Utilization of Fishes of the Noatak Valley Literature Cited NO. G- I-P Inventory and Cataloging of Kenneth T.
    [Show full text]
  • Fishing Regulations JANUARY - DECEMBER 2004
    WEST VIRGINIA Fishing Regulations JANUARY - DECEMBER 2004 West Virginia Division of Natural Resources D I Investment in a Legacy --------------------------- S West Virginia’s anglers enjoy a rich sportfishing legacy and conservation ethic that is maintained T through their commitment to our state’s fishery resources. Recognizing this commitment, the R Division of Natural Resources endeavors to provide a variety of quality fishing opportunities to meet I increasing demands, while also conserving and protecting the state’s valuable aquatic resources. One way that DNR fulfills this part of its mission is through its fish hatchery programs. Many anglers are C aware of the successful trout stocking program and the seven coldwater hatcheries that support this T important fishery in West Virginia. The warmwater hatchery program, although a little less well known, is still very significant to West Virginia anglers. O West Virginia’s warmwater hatchery program has been instrumental in providing fishing opportunities F to anglers for more than 60 years. For most of that time, the Palestine State Fish Hatchery was the state’s primary facility dedicated to the production of warmwater fish. Millions of walleye, muskellunge, channel catfish, hybrid striped bass, saugeye, tiger musky, and largemouth F and smallmouth bass have been raised over the years at Palestine and stocked into streams, rivers, and lakes across the state. I A recent addition to the DNR’s warmwater hatchery program is the Apple Grove State Fish Hatchery in Mason County. Construction of the C hatchery was completed in 2003. It was a joint project of the U.S. Army Corps of Engineers and the DNR as part of a mitigation agreement E for the modernization of the Robert C.
    [Show full text]
  • Fishing in the Seward Area
    Southcentral Region Department of Fish and Game Fishing in the Seward Area About Seward The Seward and North Gulf Coast area is located in the southeastern portion of Alaska’s Kenai Peninsula. Here you’ll find spectacular scenery and many opportunities to fish, camp, and view Alaska’s wildlife. Many Seward area recreation opportunities are easily reached from the Seward Highway, a National Scenic Byway extending 127 miles from Seward to Anchorage. Seward (pop. 2,000) may also be reached via railroad, air, or bus from Anchorage, or by the Alaska Marine ferry trans- portation system. Seward sits at the head of Resurrection Bay, surrounded by the U.S. Kenai Fjords National Park and the U.S. Chugach National Forest. Most anglers fish salt waters for silver (coho), king (chinook), and pink (humpy) salmon, as well as halibut, lingcod, and various species of rockfish. A At times the Division issues in-season regulatory changes, few red (sockeye) and chum (dog) salmon are also harvested. called Emergency Orders, primarily in response to under- or over- King and red salmon in Resurrection Bay are primarily hatch- abundance of fish. Emergency Orders are sent to radio stations, ery stocks, while silvers are both wild and hatchery stocks. newspapers, and television stations, and posted on our web site at www.adfg.alaska.gov . A few area freshwater lakes have stocked or wild rainbow trout populations and wild Dolly Varden, lake trout, and We also maintain a hot line recording at (907) 267- 2502. Or Arctic grayling. you can contact the Anchorage Sport Fish Information Center at (907) 267-2218.
    [Show full text]
  • FISHING REGULATIONS This Guide Is Intended Solely for Informational Use
    KENTUCKY FISHING & BOATING GUIDE MARCH 2021 - FEBRUARY 2022 Take Someone Fishing! FISH & WILDLIFE: 1-800-858-1549 • fw.ky.gov Report Game Violations and Fish Kills: Rick Hill illustration 1-800-25-ALERT Para Español KENTUCKY DEPARTMENT OF FISH & WILDLIFE RESOURCES #1 Sportsman’s Lane, Frankfort, KY 40601 Get a GEICO quote for your boat and, in just 15 minutes, you’ll know how much you could be saving. If you like what you hear, you can buy your policy right on the spot. Then let us do the rest while you enjoy your free time with peace of mind. geico.com/boat | 1-800-865-4846 Some discounts, coverages, payment plans, and features are not available in all states, in all GEICO companies, or in all situations. Boat and PWC coverages are underwritten by GEICO Marine Insurance Company. In the state of CA, program provided through Boat Association Insurance Services, license #0H87086. GEICO is a registered service mark of Government Employees Insurance Company, Washington, DC 20076; a Berkshire Hathaway Inc. subsidiary. © 2020 GEICO ® Big Names....Low Prices! 20% OFF * Regular Price Of Any One Item In Stock With Coupon *Exclusions may be mandated by the manufacturers. Excludes: Firearms, ammunition, licenses, Nike, Perception, select TaylorMade, select Callaway, Carhartt, Costa, Merrell footwear, Oakley, Ray-Ban, New Balance, Terrain Blinds, Under Armour, Yeti, Columbia, Garmin, Tennis balls, Titleist golf balls, GoPro, Nerf, Lego, Leupold, Fitbit, arcade cabinets, bats and ball gloves over $149.98, shanties, large bag deer corn, GPS/fish finders, motors, marine batteries, motorized vehicles and gift cards. Not valid for online purchases.
    [Show full text]
  • Preparing Trolling Lines
    CHAPTER 3 PREPARING TROLLING LINES A. TOOLS AND UTENSILS B. HOOKS -Hook types -Sharpening hooks -Ganging hooks C. 'TYPES OF FISHING LINE -Handling lines -Line characteristics D. END LOOPS IN LINE AND SINGLE-STRAND WIRE -Double figure-eight knot -Using end loops -End loops in wire E. .END LOOPS IN ROPE -Whipping and sealing rope ends -Bowline knot -Eye splice F. END LOOPS IN CABLE (MULTI-STRAND WIRE) -Wrapped end loops -Flemish eye -Crimping cable -Lazy splice G. KNOTS FOR HOOKS AND TACKLE -Palomar knot -Slip knot -Clinch knot -'Trilene' knot -Tying a hook rigid on wire H. JOINING LINES TOGETHER -Blood knot (Barrel knot) -Double slip knot -Using end loops -Connector rings and swivels I. THE ASSEMBLED TROLLING LINE -The mainline -The trace -Changing traces- Trace length -The backing J. SINKERS -Heavier line materials -Sinkers -Downriggers -Cannonballs K. DIVING DEVICES -Diving boards -Tripping -Diving lures -Trolling depth L. RIGGING FIXED LINES -Making shock absorbers -Rigging shock absorbers -Position -Backing cord and lazy line -Line storage M. RIGGING LINES ON HAND REELS -Loading the reel -Overloading -Adjustments -Using wire N. RIGGING HANDREELS FOR TROLLING -Rigging through a trolling boom -Rabbit line -Boom stays -Braking system (drag) -Lazy line 29 CHAPTER 3: PREPARING TROLLING LINES SECTION A: TOOLS AND UTENSILS Most of the preparation for trolling is normally done on shore before the fishing trip starts. This makes gear rigging easier and more comfortable, prevents new materials being contaminated with salt water before they are used, and avoids wasting time at sea which could better be used in fishing or carrying out other tasks on the boat.
    [Show full text]
  • Changes in Saltwater Angling Methods and Gear in California
    Changes in Saltwater Angling Methods and Gear in California SUSAN E. SMITH Introduction (1931), Whitehead (1931), Croker the century, as were a variety of hard­ In California, as in most other (1938a), and others. Information on wood rods made of Cuban lancewood, commercial gear and techniques has coastal states, saltwater recreational hickory, South American greenheart, also been gathered by the State of and bethabera. Multiplying baitcasting fishing has increased rapidly over the California since 1916. This type of reels I were in use, but only a few were years, and is likely to continue to information is not available for designed for saltwater fishing. Be­ increase. Recreational fish stocks, California's marine recreational fisher­ cause these early multipliers did not however, only have the capacity to ies, except in scattered reports in the have an internal drag or free-spool yield a limited sustained catch. scientific literature and in popular mechanism, the reel handles would To manage a recreational fish stock spin wildly when casting or when a rationally, its relative abundance must articles. This report traces developments in fish ran with the line. For this reason be monitored over a period of time. saltwater angling equipment from just they were coined "knucklebusters." One method widely used in assessing before the turn of the century to the Pressure was applied to the outgoing relative abundance is the collection and present. It also presents some examples line by a leather thumb brake. analysis of catch per unit ofeffort data of California fisheries that have been (i.e., catch per angler hour, catch per Fishing line was usually tarred affected by developments in sportfish­ angler day).
    [Show full text]
  • Iowa Fishing Regulations
    www.iowadnr.gov/fishing 1 Contents What’s New? Be a Responsible Angler .....................................3 • Mississippi River walleye length limit License & Permit Requirements ..........................3 changes - length limits in Mississippi Threatened & Endangered Species ....................4 River Pools 12-20 now include the entire Health Benefits of Eating Fish .............................4 Mississippi River in Iowa (p. 12). General Fishing Regulations ...............................5 • Missouri River paddlefish season start Fishing Seasons & Limits ....................................9 date changed to Feb. 1 (p. 11) Fish Identification...............................................14 • Virtual fishing tournaments added to License Agreements with Bordering States .......16 Iowa DNR special events applications Health Advisories for Eating Fish.......................17 - the definition of fishing tournaments now Aquatic Invasive Species...................................18 includes virtual fishing tournaments (p. 6) Fisheries Offices Phone Numbers .....................20 First Fish & Master Angler Awards ....................21 Conservation Officers Phone Numbers .............23 License and Permit Fees License/Permit Resident Nonresident On Sale Dec. 15, 2020 On Sale Jan. 1, 2021 Annual 16 years old and older $22.00 $48.00 3-Year $62.00 Not Available 7-Day $15.50 $37.50 3-Day Not Available $20.50 1-Day $10.50 $12.00 Annual Third Line Fishing Permit $14.00 $14.00 Trout Fee $14.50 $17.50 Lifetime (65 years old and older) $61.50 Not Available Boundary Water Sport Trotline $26.00 $49.50 Fishing Tournament Permit $25.00 $25.00 Fishing, Hunting, Habitat Fee Combo $55.00 Not Available Paddlefish Fishing License & Tag $25.50 $49.00 Give your kids a lifetime of BIG memories The COVID-19 pandemic ignited Iowans’ pent-up passion to get out and enjoy the outdoors.
    [Show full text]
  • Use of Diverse Fishing Techniques In
    International Journal of Science, Technology & Management www.ijstm.com Volume No 04, Special Issue No. 01, May 2015 ISSN (online): 2394-1537 USE OF DIVERSE FISHING TECHNIQUES IN MID- HIMALAYAN LANDSCAPE OF CENTRAL HIMALAYA, UTTARAKHAND Rakesh Verma Department of Zoology, Government Post Graduate College Pithoragarh, Uttarakhand, (India) ABSTRACT Fishes are protein providing main exploitable resources of the aquatic ecosystems. Fishing nets and gears are refers to those devices having different shape and sizes and used in the water body to capture different sizes of fishs. Present study deals with fishing techniques in Uttarakhand where fishing has its good scope. Fishing methods was observed and collected through intensive field survey, structured questionnaire, direct observation, interview methods and direct conversation to the fishermen. Various fishing nets, fish poison and use of explosives were main part of this state fishing methods. Fishing techniques adopted in Uttarakhand were simple, mostly old-fashioned, indigenous and locally manufactured. Paper also focuses on various techniques as well as their independent contribution in state fishing. Gill net, Cast net, Dragged net, Dip net, Hand net, Hanging rope, Trap, Hook, Line and Explosives were mainly used other than that six chemical poisons and thirteen Icthyo-toxic plants were observe which was used by the local fishermen. Explosives and Icthyo-poisons were polluting and damaging aquatic ecosystem by various ways and was one of the main causes of aquatic biodiversity loss. Keywords: Central Himalaya, Fishing Techniques, Fishing Gears, Fishing Nets, Fish Poison, Hill Stream Fishing I. INTRODUCTION The fishes are one of the main exploitable resources of the aquatic ecosystems that provide a major source of protein.
    [Show full text]
  • Code of Colorado Regulations
    DEPARTMENT OF NATURAL RESOURCES Division of Wildlife CHAPTER 1 - FISHING 2 CCR 406-1 [Editor’s Notes follow the text of the rules at the end of this CCR Document.] ARTICLE 1 - GENERAL PROVISIONS #100 – DEFINITIONS See also 33-1-102, C.R.S and Chapter 0 of these regulations for other applicable definitions. A. "Artificial flies and lures" means devices made entirely of, or a combination of, natural or synthetic non-edible, non-scented (regardless if the scent is added in the manufacturing process or applied afterward), materials such as wood, plastic, silicone, rubber, epoxy, glass, hair, metal, feathers, or fiber, designed to attract fish. This definition does not include anything defined as bait in #100.B below. B. “Bait” means any hand-moldable material designed to attract fish by the sense of taste or smell; those devices to which scents or smell attractants have been added or externally applied (regardless if the scent is added in the manufacturing process or applied afterward); scented manufactured fish eggs and traditional organic baits, including but not limited to worms, grubs, crickets, leeches, dough baits or stink baits, insects, crayfish, human food, fish, fish parts or fish eggs. C. "Chumming" means placing fish, parts of fish, or other material upon which fish might feed in the waters of this state for the purpose of attracting fish to a particular area in order that they might be taken, but such term shall not include fishing with baited hooks or live traps. D. “Game fish” means all species of fish except prohibited nongame, endangered and threatened species, which currently exist or may be introduced into the state and which are classified as game fish by the Commission.
    [Show full text]