Fish capture technology encompasses the process of catching any aquatic animalDocument Transcript
Fish capture technologyFish capture technology encompasses the process of catching any aquatic animal,using any kind of fishing methods, often operated from a vessel. Use of fishingmethods varies, depending on the types of fisheries, and can range from a simpleand small hook attached to a line to large and sophisticated midwater trawls orpurse seines operated by large fishing vessels. The targets of capture fisheries caninclude aquatic organisms from small invertebrates to large tunas and whales,which might be found anywhere from the ocean surface to 2 000 meters deep.The large diversity of target species in capture fisheries and their wide distributionrequires a variety of fishing gear and methods for efficient harvest. Thesetechnologies have developed around the world according to local traditions and, notleast, technological advances in various diciplines.In recent decades major improvements in fiber technology, along with theintroduction of other modern materials, have made possible, for example, changesin the design and size of fishing nets. The mechanization of gear handling hasvastly expanded the scale on which fishing operations can take place. Improvedvessel and gear designs, using computer-aided design methods, have increased thegeneral economics of fishing operations. The development of electronic instrumentsand fish detection equipment has led to the more rapid location of fish and thelowering of the unit costs of harvesting, particularly as this equipment becomesmore widespread. Developments in refrigeration, ice-making and fish processingequipment have contributed to the design of vessels capable of remaining at sea forextended periods.Although these technologies are largely available, those actually introduced in manysmall-scale fisheries may amount to no more than motorizing a dugout canoe, useof modern and lighter gear or introducing the use of iceboxes to ensure the qualityof the product landed.The impact of such changes, however, has considerably increased landings and theearnings of fishers, and underlines the need for effective management to preventexcessive fishing effort. The emphasis of much recent technical innovation has beenfocused on greater and more appropriate selectivity of fishing gear so as to reducenegative impacts on the environment.
Fishing vesselsThe vast majority of commercial vessels load and discharge cargo in the safety ofports; their main function at sea is transportation. A fishing vessel differs in that itis used to hunt, locate, catch, load (and sometimes discharge), as well as processand conserve cargo at sea, all in variable weather conditions. In effect, it is a placeof work and is a very specialized vessel which is intended to perform all these welldefined tasks. The size, deck layout, carrying capacity, accommodation, machineryand equipment of fishing vessels are all related to its function in carrying out itsplanned operations.Factors which influence the design of a fishing vessel may be grouped under thefollowing headings: The species, location, abundance and dispersion of the fish resources Fishing gear and methods Geographical and climatic characteristics of the fishing area Seaworthiness of the vessel and safety of the crew Handling, processing and stowage of catch Availability of finance Availability of boatbuilding and fishing skills Laws and regulations applicable to fishing vessel design, construction and equipment Choice and availability of construction materials Economic viabilityBecause of the inherent variations in each of these factors, the diversity of fishingvessels designs operating around the world is enormous, ranging from 2 metre dugout canoes to factory trawlers exceeding 130 metres in length, with trip durationsranging from a few hours to over a year.Technological developmentsThe size and autonomy of a fishing vessel is largely determined by its ability tohandle, process and store fish in good condition on board, and thus these twocharacteristics have been greatly influenced by the introduction and utilization ofice and refrigeration machinery. Other technological developments - especiallyhydraulic hauling machinery, fishfinding electronics and synthetic twines - have alsohad a major impact on the efficiency and profitability of fishing vessels. Indeveloping countries, fishing operations have been greatly influenced by theintroduction and widespread use of the outboard engine.All these technological developments have not only heavily influenced the design offishing vessels, but, particularly between 1950-1980, resulted in increasedproductivity, profitability and competition to the extent that many stocks becamefully or overexploited. This situation lead to fisheries management measures whichincluded control of fishing effort, sometimes imposed through length limits on
fishing vessels. The effect on fishing vessels was seen with designers attempting tomaximize the vessels fishing capacity while maintaining its length within limits. Factory trawler FAO/FIIT/J.TurnerWorld fishing fleetIn 2002 the world fishing fleet numbered about four million vessels: about one-third were decked while the remaining two-thirds were undecked (generally lessthan 10 m in length). Of the latter, 65 percent were not fitted with mechanicalpropulsion systems. There is little information available for the undecked/non-motorized vessels but it is estimated that Asia accounts for over 80 percent ofthem.The average size of decked vessels remains about 20 GT (around 10-15 metres).Those larger than 100 GT (or longer than 24 m) amounted to about 1 percent ofthe world fishing fleet. China has approximately 50 percent (25 600) of these largervessels, while no other country has more than 10 percent of this fleet and about 10countries together account for 80 percent of the total.The first-hand statistics on fisheries employment are scarce, incomplete and of lowquality. According to FAO records, employment in the primary capture fisheries andaquaculture production sectors in 1998 was estimated to have been about 37million people, including full-time, part-time and occasional workers. About 60% ofthem are employed in marine fisheries. About two-thirds of these fishermen workonboard fishing vessels of less than 12 m in length, both decked and undecked.Safety of the vessel and its crew are considered a paramount design consideration.Despite this fact, there is no international instrument in force concerning the safetyof fishing vessels. International conventions and agreements awaiting ratificationwhich concern safety at sea are almost exclusively aimed at vessels 24 metres inlength and over (which, in terms of numbers, constitute only about one percent ofall vessels in the worlds fishing fleet), and therefore do not apply to artisanalvessels and transport boats in developing countries. Safety regulations for allfishing vessels are left almost entirely to national discretion.Code of safetyFortunately, however, in 1999 IMO invited FAO and ILO to cooperate in the revisionof Part B of the Code of Safety for Fishermen and Fishing Vessels, for vessels of
24m in length and over, as well as, the Voluntary Guidelines for the Design,Construction and Equipment for Small Fishing Vessels, that is vessels of 12m inlength and over but less that 24 m in length. In addition Part A of the Code wasincluded in the revision. Tuna purse seiner Courtesy of NOAA/J.CortThe revised Code and the Voluntary Guidelines were approved by IMO in 2004. Atthe twenty-sixth session of the Committee on Fisheries in March 2005, FAOwelcomed the revised Code and Voluntary Guidelines and recommended the earlypublication by IMO of these documents. The Governing Body of ILO approved therevised texts later the same year.In December 2004, IMO agreed to include in the work programme of the Sub-Committee on Stability and Load Lines and on Fishing Vessel Safety (SLF) a newhigh priority item on “Safety of small fishing vessels”. The aim being to developsafety recommendations for decked fishing vessels of less than 12m in length andundecked vessels of any length, bearing in mind that the largest majority of fishingfatalities occur aboard such vesselsIn September 2005, the SLF Sub-Committee reviewed a document submitted byFAO that outlines ideas relating to the development of the new safety standardsand confirms FAO’s commitment to the exercise. The Sub-Committee establishedan intersessional correspondence group and approved a timeframe for thedevelopment of the safety standards with a target completion date of 2009.In 2006, it was agreed that the title of the proposed new standards should be:Safety recommendations for decked fishing vessels of less than 12 metres in lengthand undecked fishing vessels.The purpose of the safety recommendations is to provide guidelines to competentauthorities for the design, construction, equipment and training of the crew of smallfishing vessels.The FAO/ILO/IMO initiative would be timely when it comes into effect since theaverage age of the worlds fleets is increasing and it could be envisaged that there
would have to be an increase in new building in the foreseeable future, if thishappens there would be at the very least reasonable safety standards to follow.Fishing gears and methodsDefinitionsMethods to catch fish and other aquatic resources, with or without a gear, havealways been practiced. Although the fundamental principles, i.e. filtering the water,luring and outwitting the prey and hunting, are the basis for most of the fishinggears and methods used even today, gears and methods have changed significantlyover time and their capture efficiency is obviously hardly comparable to that ofprehistoric times.A fishing gear is the tool with which aquatic resources are captured, whereas thefishing method is how the gear is used. Gear also includes harvesting organismswhen no particular gear (tool) is involved. Furthermore, the same fishing gear canbe used in different ways. A common way to classify fishing gears and methods isbased on the principles of how the fish or other prey are captured and, to a lesserextent, on the gear construction. Pulling in fishing nets FAO/17099/M.MarzotFAO defines and classifies the main categories of fishing gear as follows: 1. Surrounding nets (including purse seines) 2. Seine nets (including beach seines and Boat, Scottish/Danish seines) 3. Trawl nets (including Bottom: Beam, Otter and Pair trawls, and Midwater trawls: Otter and Pair trawls) 4. Dredges 5. Lift nets 6. Falling gears (including cast nets) 7. Gillnets and entangling nets (including set and drifting gillnets; trammel nets) 8. Traps (including pots, stow or bag nets, fixed traps)
9. Hooks and lines (including handlines, pole and lines, set or drifting longlines, trolling lines) 10.Grappling and wounding gears (including harpoons, spears, arrows, etc.) 11.Stupefying devicesThis classification is being slightly modified to accommodate the most recentdevelopment of fishing gears and methods and will soon be published. Pole and line gear FAO/Andrey UrcelayetaFishing methods have continuously evolved throughout recorded history. Fishersare inventive and not afraid of trying new ideas. The opportunities for innovationhave been especially good in recent decades with advances in fibre technology,mechanization of gear handling, improved performances of vessels andmotorization, computer processing for gear design, navigation aids, fish detectionto mention only a few technologies.Whereas technological development of fishing gear and methods in the past wasaimed to increase production, the present situation with many overfished stock,limited possibilities to expand fishing on underexploited resources and concernsabout the environmental impact of fishing operation, gear development is now verymuch focussed on selective fishing and gears with less impact on the environment.
Artificial reefsBackgroundArtificial reefs are structures placed on the sea bottom to gather fish. They areeither used alone or with Fish Aggregating Devices (FADs). Most artificial reefsare large, permanent structures set in rather shallow water. Generally they aremade of modern synthetics and hardware (concrete, metal, plastic pipes) which aresometimes finished using local vegetal materials (bamboo, coconut, leaves, coir forthe anchor rope, etc.). In some cases lighter structures made from local materialsare installed temporarily to lure fish to a specific area, during a certain fishingseason.Artificial reefs are established for various purposes: to enhance resources in coastal waters in order to facilitate exploitation; to create a biological reserve; and, to prevent the use of certain fishing gear, particularly bottom trawls, in a given area.Construction and maintenanceDifferent structures can be used as artificial reefs, such as wrecks, offshore oil rigsand pipelines on the sea bottom, heaps of oyster shells, etc. as well as specificallydesigned modules.Constructions covering a large area can be composed of individual modules, ofwhich there are many models depending on the purpose.For instance, to prevent trawling, a model might consist only of slabs of concretewith stakes. To enhance resources, that is to provide shelters for certain fishes andfish aggregation in general, modules should include holes (big enough to avoidbeing quickly sealed by marine organisms) where the material can facilitate thefixing of "fouling" organisms as food for aggregating fish.The overall dimensions of the reef and numbers and sizes of the holes for shelterare critical factors, as well as waves around it (modules should not bury themselvesin bottom sediment). The modules should be bulky enough to project from theocean bottom and massive enough to remain in place (even during severe storms);it might be suitable to anchor the modules of the artificial reef, particularly inshallow waters.Material should resist rapid corrosion and should not introduce harmful substancesinto the marine environment. Various elements can be used to create artificialreefs, including:
scrap material (car, old ships and barges, scrap concrete, household appliances, rock and rubble from excavations, etc.); baled urban solid waste; products such as sandbags and bamboo frames to construct temporary "reefs"; large concrete blocks, elements made from FRP and PVC; and, offshore structures for oil or gas exploitation can also serve as artificial reefs and fish aggregating devices.Building costs and installation factors (a very large number of artificial reefs mustbe set up) are also considerations in the choice of modules used. In shallowerwaters, setting FADs in conjunction with an artificial reef has proven profitable inseveral places. It has not been possible to identify a single model which could beuniversally recommended.Aggregation processAn artificial reef plays the role of an offshore bank and protected area or park. Theprocess of aggregation is often made in several steps: concretizing the blocks, thenaggregating small fish and finally attracting larger fish.The first few fish species arrive and eat organisms which have fixed on the artificialreefs which act as a food reservoir for demersal fish. Then, other species, such aspredators of the former come. For certain species (rock fish, octopus, crustaceans)artificial reefs are shelters; for small fish/juveniles, reefs provide protection frompredators. Artificial reefs are also spawning areas for certain species (e.g.cephalopods) which explains how artificial reefs can enhance resources. In shallowwaters shoals of small pelagic fish have been observed to use artificial reefs asstopping grounds. A typical school of the sparid, Montaxis grandoculis (Mu), circling an artificial reef. This fish primarily eats molluscs Courtesy of Dr. James P. McVey/NOAA Sea Grant ProgramImpact of artificial reefsEnhancement and recruitment
It takes weeks for a new artificial reef to attract fish and for the establishment offish colonies/populations. Artificial reefs mainly concentrate on the remainingresource and the potential enhancement effect is, in general, considered quite low.In terms of habitat rehabilitation, artificial reefs have little, if any, success as theyonly concern a limited area.It is worth observing that the assessment of some possible habitat rehabilitationand production enhancement would require a careful survey over a long period withregular data collection and careful monitoring of all fishing activities and in-depthknowledge of local ecosystems and ecological mechanisms. In most cases it is verydifficult to evaluate fishing activity on artificial reefs. Therefore, regarding thepotential socio-economic impact, there is a lack of thorough economic analyses ofthe costs and benefits of artificial reefs.In general, the establishment of artificial reefs in coastal areas can facilitate smallerscale fishing activities with passive gears such as lines, pots and gillnets. In someplaces, recreational fishers also benefit from the creation of artificial reefs.BiologicalRegarding the biological impact of artificial reefs, two theories exist concerning thenumber of fish and fish species using reefs: competition for limited resources, such as food and shelter is the chief factor; and, fish mortality and recruitment are essential. The potential advantage from reefs could be a reduction in mortality (for instance by providing refuge from predators for small fish/juveniles) and/or recruitment stability.Fish behaviour on artificial reefs differs from one species to another. This factdetermines the different aggregating ability of the artificial reef for various species.Legal Aspects and RegulationLegal aspects related to artificial reefs include: ownership of the artificial reef; ownership of the fish on it; limitation/prevention of certain fishing gear and therefore certain fisheries, resource utilization and management; and, shipping and navigation.A number of countries have set up strict regulations concerning the position of theartificial reefs, design and material used, proper marking, issue of a governmentauthorization, amount of fishing gear authorized, regular reporting of fishingactivities on artificial reefs, etc.
Any national regulation must take into consideration the provisions of UNCLOS(United Nations Convention on the Law of the Sea), conventions on navigationalsafety, shipping routes, conventions on dumping at sea, and decisions by fisheriesmanagement bodies.When offshore structures for oil or gas exploitation act as a permanent fishaggregating device or artificial reef, they are covered by international standardsand guidelines developed by the International Maritime Organization (IMO).ConclusionThe creation of artificial reefs has changed the perception of fishery resources froma primarily competitive hunting attitude to a collaborative rearing and nursing one.In addition to direct impact of local fisheries, performances and revenues, artificialreefs have side-impacts on other fisheries and related activities in terms of catchesand incomes.Where there is heavy or overexploitation, deployment of artificial reefs appears tobecome an alternative to more traditional development efforts of artisanal fisheriesfor effective near-shore fishery resources management. It is worth mentioning thatthe settlement of such structures introduces important changes in the managementof fishing operations: e.g. fishing rights, working time allocation, relationshipamong fisher groups and between small and larger scale fisheries.Fishing equipmentFishing equipment varies in sophistication depending on the size of the vessel andthe technology used. Generally, on-board equipment can be categorized into threecategories: related to the wheelhouse, to the fishing environment and to handling.Wheelhouse equipment: this includes equipment for navigation, electronicinstruments and communications. It is often clustered around the skippers chair --in larger vessels, where the command console is at the centre of the bridge, thereis an additional chair for a co-pilot. Main displays are shown on monitors in front ofthe control position (increasingly shown on one large integrated display);instruments or monitors that are used more infrequently are mounted in thedeckhead (ceiling).Navigational instruments – compass, autopilot, GPS, etc. – are those used formanoeuvering the vessel while at sea and in harbour. Fish detection instruments,such as echosounders and netsounders, are used to search for fish and during thefishing operation. Communication instruments are vitally important for the safetyand for general communications (including among crew). These include simple radiodevices to EPIRBs and global maritime distress systems.
Environment equipment: this includes devices used during fishing operations,such as medina panels and fisheyes. This equipment can also be fitted to gears,such as Turtle Excluder Devices and Bycatch Reduction Devices, aimed atminimizing adverse impacts to the ecosystem.Handling equipment: this includes equipment used for on-board fish handling andprocessing, such as brailers or fish pumps. It also comprises gear handlingequipment, such as drums and haulers which are used to spool and bring in nets.Types of fisheriesCapture fisheries are extremely diversified, comprising a large number of types offisheries that are categorized by different levels of classification. On a broad level,capture fisheries can be classified asindustrial, small-scale/artisanal andrecreational. A more specific level includes reference to the fishing area, gear andthe main target species, such as the North Sea herring purse seine fishery, Gulf ofMexico shrimp trawl fishery, southern ocean Patagonian toothfish longline fishery.While capture fisheries encompass thousands of fisheries on a global scale, they areoften categorized by the capture species, the fishing gear used and the level atwhich a fishery is managed nationally and/or regionally.The following brief descriptions provide an overview of capture fishery types.Industrial fisheriesCapital-intensive fisheries using relatively large vessels with a high degree ofmechanization and that normally have advanced fish finding and navigationalequipment. Such fisheries have a high production capacity and the catch per uniteffort is normally relatively high. In some areas of the world, the term "industrialfisheries" is synonymous with fisheries for species that are used for reduction tofishmeal and fish oil (e.g. the trawl fishery for sandeel in the North Sea or thePeruvian ourse-seine fishery for anchoveta).Small-scale fisheriesLabour-intensive fisheries using relatively small crafts (if any) and little capital andequipment per person-on-board. Most often family-owned. May be commercial orfor subsistence (see below). Usually low fuel consumption. Often equated withartisanal fisheries.Artisanal fisheriesTypically traditional fisheries involving fishing households (as opposed tocommercial companies), using relatively small amount of capital, relatively smallfishing vessels, making short fishing trips, close to shore, mainly for localconsumption. In practice, definition varies between countries, e.g. from hand-
collection on the beach or a one-person canoe in poor developing countries, tomore than 20 m. trawlers, seiners, or long-liners over 20m in developed countries.Artisanal fisheries can be subsistence or commercial fisheries, providing for localconsumption or export. Sometimes referred to as small-scale fisheries In general,though by no means always, using relatively low level technology. Artisanal andindustrial fisheries frequently target the same resources that may give rise toconflict. Artisanal fishing FAO/Fisheries DepartmentRecreational (sport) fisheriesHarvesting fish for personal use, leisure, and challenge (e.g. as opposed to profit orresearch). Recreational fishing does not include sale, barter or trade of all or part ofthe catch.Commercial fisheriesFisheries undertaken for profit and with the objective to sell the harvest on themarket, through auction halls, direct contracts, or other forms of trade.Subsistence fisheriesA fishery where the fish caught are shared and consumed directly by the familiesand kin of the fishers rather than being bought by intermediaries and sold at thenext larger market. Pure subsistence fisheries are rare as part of the products areoften sold or exchanged for other goods or servicesTraditional fisheriesFisheries established long ago, usually by specific communities that have developedcustomary patterns of rules and operations. Traditional fisheries reflect culturaltraits and attitudes and may be strongly influenced by religious practices or socialcustoms. Knowledge is transmitted between generations by word of mouth. Theyare usually small-scale and/or artisanal.
Safety at seaFishing: dangerous occupationIn recent years, little progress has been made in improving the safety of fishersdespite attempts by FAO and others to raise awareness of the severity of theproblem. Fishing at sea is probably the most dangerous occupation in the world.The International Labour Organization (ILO) estimates that 24 000 fatalities occurworldwide per year in capture fisheries.The consequences of loss of life fall heavily on the dependants. In many developingcountries, these consequences can be devastating. Widows often have a low socialstanding, and where there is no welfare state to support families and no alternativesource of income, widows and their children may face destitution.The safety of fishing vessels and fishers involves several interrelated components,such as the design, construction and equipment of vessels. However, social andeconomic pressures as well as overcapacity and overfishing of coastal resources areprobably the major factors that have negated efforts to improve safety at sea. Onfishing boats, particularly small vessels, crews have to work at sea, on deck in allweathers, frequently with hatches open, in order to locate, gather and process theircatch. Working conditions and efficiency have improved in many ways withincreased mechanization. However, new dangers have arisen and the strain on thecrew remains considerable, not least because of reductions in crew size to cutcosts.The persistent view that fishing vessels can only be made safer through: regulations that affect their design, construction and equipment; and the training and certification of crews.While such interventions may yield effective results, data suggest that this is onlysometimes the case. Human behaviour or error is estimated to be responsible for80 percent of accidents in the fishing industry.Most accidents occur as a result of poor judgement exercised during fishingoperations, brought about by the pressure to increase profits (or simply to remainfinancially viable). In a situation of overcapacity and overfishing, the competition tocatch limited resources is intense. The need for economic survival leads to risk-taking and insufficient crew size.Role of fisheries managementFisheries management regimes affect safety. Therefore, improved safety shouldbecome an explicit objective of fisheries management, which must ensure that thefishing effort is commensurate with the state of fishery resources. The main lessonlearned from FAO’s experiences in implementing safety activities is that
recommendations, no matter how sound, do not form an adequate basis foradministrations to act or for industry to respond. Despite the development ofinstruments and guidelines related to the design, construction and equipment offishing vessels (with more stringent regulations at national level), the accident ratein the fishing industry remains unacceptably high.Cooperation with ILOLong-standing cooperation between FAO and the ILO and the International MaritimeOrganization (IMO) has led to the development of guidelines and standards on thesafety of fishing vessels and fishers: the FAO/ILO/IMO Code of Safety of Fishermenand Fishing Vessels, Parts A and B; the FAO/ILO/IMO Voluntary Guidelines for theDesign, Construction and Equipment of Small Fishing Vessels; and theFAO/ILO/IMO Document for Guidance on Training and Certification of Fishing VesselPersonnel.Recently, the FAO/ILO/IMO Code of Safety for Fishermen and Fishing Vessels (PartsA and B) and the FAO/ILO/IMO Voluntary Guidelines have been revised. Currently,FAO is working with the ILO and IMO to develop new safety standards for smallfishing vessels not covered by the revised code and guidelines. The provisional titleof these new standards is Safety recommendations for decked fishing vessels ofless than 12 metres in length and undecked fishing vessels. The target completiondate for this work, which also includes the development of guidelines for theimplementation of Part B of the Code of Safety for Fishermen and Fishing Vessels,the Voluntary Guidelines and the Safety Recommendations, is 2010.Raising awarenessThe need for awareness raising among governments, fishing-vessel owners, fishers,boatbuilders and other stakeholders of the safety issue will grow. It is not unlikelythat consumers will put pressure on the fishing industry and on governments toimprove health and safety conditions on board fishing vessels. This is related totheir concerns on overfished stocks, the safety and quality of fish products,environmental protection, and illegal, unreported and unregulated (IUU) fishing.