Fisheries WK 10(1).ppt

8/19/2019 Fisheries WK 10(1).ppt

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Management of Marine &freshwater Fisheries Resources

Miller $ Spoolman 17th edition, Chapter,8, 9 & 11

Miller 12th Edition Chapter 14


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Classes of Marine & freshwater Resoures

Physical resources

Mineral deposits, petroleum, natural !as, freshwater

Biological resources

"lants and animals, miro#es

Energy resources

Ener! from heat or motion of water

Non-extractive resources

%ransportation, rereation, waste disposal


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•

A fishery is a onentration of a partiular wild fishspeies suita#le for ommerial harestin! in a !ienoean area or inland #od of water'

• Fish print the area of oean(inland water #od neededto sustain the fish onsumption of an aera!e person, anation, or the world'

•

East )fria fisheries omprises freshwater and themarine su#*setor'

+isheries


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East )frian fisheries sites

• %he fisher sites inlude a-e %an!ani-a a-e Malawi a-e .itoria

a-e %ur-ana a-e /iu 0ndian ean

• Fish diversity is high with more

than 4,000 spp in Indian ocean


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%he la-e ontains 2,73 -m olume of water

5orld6s seond lar!es freshwater la-e

)#out 33 endemi fish speies man hae #eome etint afterintrodution of :ile perh

http;((fish'mon!a#a'om(data(eosstems(a-e


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0mportane of the fisheries industr?i@ +isheries Contri#ute to ountrAs eonom

emploment reation

inome !eneration and forei!n ehan!e earnin!s

auiliar industries suh as net ma-in!, pa-a!in!material industries and #oat #uildin! amon! others

?ii@ Soure of food ?fillet@

+ish is a rih soure of protein and essential amino aidssuh as lsine'

0t ontains polunsaturated lipids and also has minerals

e'!' alium, phosphorous, iron as well as itamins ), B1, B2,and '


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?iii@ Soure of mediines* e'!' ome!aAs assoiated with

seeral health #eneifts?i@ +ishmeal* Soure of food for liesto- ?ow@ and otheranimals

?@ Sales and #ones used for fertilser, ornaments et'

?i@ S-in* for shoes, #elts, purses

?ii@ Swim #ladder*raw material from whih isin!lass ?tpe ofolla!en@, used as refinin! a!ent in the manufature of#eers and wines,


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%hreats to marine and +reshwaterfisher resoures


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!i" #a$itat loss an% %egra%ation

•

Some 90% of sh living in the ocean spawn on coralreefs in coastal wetlands and marshes, in mangroveforests or in rivers.

• All of these ecosystems are under intense pressurefrom human activities


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• Provide habitats for one!uarter of all marineorganisms.

• "conomically, coral reefs produce about onetenth ofthe global sh catch and they provide shing andecotourism #obs for some of the world$s poorestcountries.

• y &00', (9% of world coral reefs had been destroyedand &0% degraded due to) *i+ oastal development

*ii+ Pollution*iii+ -vershing*iv+ armer ocean temperatures *('/0 0 is optimum for coralreefs+,*v+ ncreasing ocean acidity*vi+ ncreased turbidity runo1 of soil and other materials fromthe land can cloud the water and bloc2 sunlight needed by the

Coral reefs


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oastal sea-grass $e%s• Sere as nurseries for man speiesof fish and shellfish, whih in turnfeed fishes in other marine ha#itats'

•

8< of the sea*!rass meadowsaround the world hae #een de!radedor destroed, mostl # %re%ging andoastal deelopment'

Figure '-() page *+,


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!ii" nvasive .pecies

eli#erate or aidental introdution of hundreds of harmful inasiespeies into oastal waters, wetlands, and la-es throu!hout the world

Ballast water arried in ships 6 #allast tan-s to improe sta#ilit and#alane an #e a soure of inasie speies


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Eample of inasie speies

*a+ the Asian swamp eel native to Asia, fromnorthern ndia and urma to hina. 3as invaded

water ways of south 4lorida

5hey were probably introduced to 6orth America bya!uarium release, stoc2ing as a food source, or

escaped from sh farms during 7ooding events.

Swamp eels have established populations in 4lorida,8eorgia, and 3awaii on the island of -ahu.


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t reproduces rapidly andeats almost anything


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t reproduces rapidly and eat a broad range of prey,

including sh, shrimp, craysh, frogs, turtle eggs, anda!uatic invertebrates *e.g., worms and insects+.

t can survive cold weather, drought, and predatorsby burrowing into mud ban2s

t can wriggle across dry land to invade newwaterways, ditches, canals, and marshes

.


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S:S;


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!$" /a0e 1ictoria

•%he la-e has #een in eolo!ial trou#le for more than 2 deades'

•Dntil the earl 1983s, the la-e had 33 speies of fish found nowhereelse'

• 83< were small fish -nown as ihlids whih feed mostl on detritus,al!ae, and ooplan-ton'

•Sine 1983, some 233 of the ihlid speies hae #eome etint, andothers are threatened

•+ators that hae aused loss of aFuati #iodiersit in the la-e inlude

introdution of :ile perh and water =ainth


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Figure **-,) page 23,

• Nile perch• eli#eratel introdued into the la-e

?193s and 193s@ to stimulate the#usiness of eportin! fish from the la-e to

ED

• %he population of :ile perh eploded anddeoured the ihlids

0nasion in the late 1983s of waterhyacinth4

#lo-ed sunli!ht depried fish and plan-ton of o!en redued the diersit of important

aFuati plant speies'

Fi ure **-3 a e 2+3

!iii" P l ti 5 th % P ll ti


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!iii" Population 5rowth an% Pollution

• 0nrease in human population alon! oastal ities has added to thealread intense pressure on the worldAs oastal ones #

estroin! more aFuati ha#itat

0nreasin! pollution

• =i!h population* the oeans are #eomin! more rowded more #oats,off*shore onstrution, rereation, and oil and !as eploration anddrilled wells

• Eutrophication lead to al!al #looms, fish die*offs, and de!radation of

eosstem series

• 6oxic pollutants from industrial and ur#an areas -ill some forms ofaFuati life


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!iv" limate hange

• "ro>eted limate han!e threatens aFuati #iodiersit andeosstem series, partl # ausin! sea leels to rise

• Rise in sea leel would destro more oral reefs, swamp some low*lin! islands, drown man hi!hl produtie oastal wetlands and

man!roes

• Corals will #e more hallen!ed to surie and !row as oeans#eome warmer and more aidi due to inreased leels ofdissoled ar#on dioide


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14 7verfishing an% Extinction

• +ishin! has #eome hi!hl industrialied to meet the !rowin! demand

of fisheries produts

• =u!e essels use powerful tehnolo!ies to apture fish in hu!e olumes• Een proess and freee their athes while at sea

• Modern industrial fishin! has aused 83< depletion of some wild fishspeies in onl 13G1 ears

•

%he human demand for seafood is met throu!h fisheries'


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• %he !lo#al fishprint has #eome unsustaina#le'

• )ll nations to!ether are oerfishin! the worldAs !lo#al oeans ta-in!7< more than the sustaina$le yiel%'

Sustaina#le ield maimum amount of fish that an #e harested

without depletin! future sto-s erfishin! leads to commercial extinction) whih ours when it is no

lon!er profita#le to ontinue harestin! the affeted speies


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Fishfarming in

cage

Trawlershing

potter airplane

onar!urse-seine

shing

"rift-net shing

#ong lineshing

Float $uo%

lineswith

hoo&s

Fish caught '% gills

"eep seaa(uaculture

cage

ommercial 4ishing


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%rawler fishin! •Dsed to ath fishes and shellfish thatlie on or near the oean floor e'!' od,flounder, shrimp

•0t inoles dra!!in! a funnel*shaped net held open at the ne- alon! theoean #ottom'

•

%rawlin! scrapes up almost eerthin!that lies on the oean floor and oftendestros #ottom ha#itats


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Purse-seine fshing

•>sed to catch surface-dwelling species e.g.tuna, mac2erel, anchovies, and herring, which

tend to feed in schools near the surface or inshallow areas.

•A purse seine is a net set vertically in thewater.

•hen a school of tuna is sighted, the purseseine vessel encircles the school and trapsthem in the net by lin2ing bac2 up with asmaller vessel.

•Purse Seine is an e=tremely consistent ande?cient method, enabling shers to catch andfree@e large !uantities of tuna. • 4loating ob#ects that attract sh, either natural or

manmade ob#ects li2e 4As are used to increasee?ciency.

http://www.youtube.com/embed/xWAKevZK26ohttp://www.youtube.com/embed/xWAKevZK26ohttp://www.youtube.com/embed/xWAKevZK26o


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• :ets that are used to apture ellow fin tuna in the eastern tropial"aifi ean hae -illed lar!e num#ers of dolphins that swim on thesurfae a#oe shools of tuna'

+ h l l l


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• 0noles puttin! out lines up to 133 -mlon!, hun! with thousands of #aitedhoo-s'

• %he depth of the lines an #e ad>ustedto ath open*oean fish speies e'!'swordfish, tuna, and shar-s or oean*#ottom speies e'!' od'

+ishin! essels Dsin! lon!*linin!

• on!lines also hoo- and -ill lar!e num#ers of endan!ered sea turtles,dolphins, and sea#irds eah ear

Bla-*#rowed al#atross is endan!ered

on!line and trawler fishin! fleets hoo-s

and nets apture and drown these #irdswhen the die into the water for food'Figure (-*() Page 28'4

it t f hi


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rit-net fshing•+ish are au!ht # hu!e driftin! nets that anhan! as deep as 1 m ?3 ft@ #elow the surfaeand etend to 4 -m lon!'

•+ish !ills !et stu- in the holes in the net

•Can lead to oerfishin! of the desired speiesand ma trap lar!e Fuantities of unwanted fish?#$ath@

Figure **-*8) Pg 292

Endan!ered leather#a- sea turtleentan!led in a fishin! net


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)Fuaulture

)l - f i


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• )lso -nown as a:ua farming

• +isheries and aFuaulture ?fish farmin!@ suppl a#out 7<of the worldAs food'

• )Fuaulture is the onl ia#le alternatie soure of fishespeiall at this time when the natural sto-s of fish aredelinin!'


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?ii@ Algaculture; "rodution of seaweeds and other al!ae

?iii@ Pisciculture; +resh water +ish farmin! e'!' farmin! of +infishes ?e'!' %ilapia@

+resh water fish farmin! is !rouped into two in /ena

ol% water culture ulture of Rain#ow trout?norhnhus m-iss@ in hi!hlands

;arm water culture ulture of %ilapine fishes, )frianatfish, ommon arp and a ariet of ornamental fishes inlow land re!ions of the ountr

Marine water aFuaulture is under deeloped

!iv" A:uaponics!iv" A:uaponics


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!iv" A:uaponics!iv" A:uaponics

) food prodution sstem that om#ines conventional a:uaculture?raisin! aFuati animals in tan-s@ with hy%roponics in a sm#ioti

enironment'

0n normal aFuaulture, eretions from the animals #ein! raised anaumulate in the water, inreasin! toiit'

0n an aFuaponi sstem, water from an aFuaulture sstem is fed to ahdroponi sstem

)Fuaulture #*produts are #ro-en down # nitrifiation #ateria intonitrates and nitrites, whih are utilied # the plants as nutrients'

%he water is then reirulated #a- to the aFuaulture sstem


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f l


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ncrease the total world food

production

nstead of hunting marine life,cultivate it

ncrease food security

A!uaculture production in the >nited States is valuedat B(.( billion

n 4lorida) BC0(00 million

0mportane of aFuaulture


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• "rodue lots of waste produts

• Eess nutrients ause harmful al!ae #looms

•

%he food used to feed lar!er fish eploit another population;* non*sustaina#le fisheries


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Sustaina#le +isheries Mana!ement

!i" E ti ti % M it i Fi h


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!i" Estimating an% Monitoring Fishery

•

%his helps monitor arious fish speies population oer time'

• Can adises on when to*

sharpl redue fish harests

Close some oerfished areas until the reoer'

!ii" Regulate Fish #arvests


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!ii" Regulate Fish #arvests

%he !oernments ma re!ulate fish harest #;

imitin! fishin! seasons ? allow fish to #reed@

Re!ulatin! the tpes of fishin! !ear that an #e usedto harest a partiular speies

Settin! low ath limits

!iii" R % limi t 5 m t . $ i%i


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!iii" Re%uce or eliminate 5overnment .u$si%ies

8overnments all over the world give a total of about)*+* 'illion per year in subsidies to shers to help2eep their businesses running

About B&0 billion helps shers to buy ships, fuel, andshing e!uipmentD

Appro=imately B(E pays for research and managementof sheries

3ence the bul2 of the money from governmentsubsidies *B(0F(E+ each year is spent to encourageovershing and e=pansion of the shing industry.

5he result is too many boats chasing too few sh.


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/0 #aws and Treaties

• "rotet some endan!ered and threatened marine and fresh water fish

speies

• E'!' %he D'S' Endan!ered Speies )t ?Chapter 9, pp' 239G11@ andseeral international a!reements hae #een used to identif andprotet endan!ered and threatened marine speies'

/i0 Consumer information


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/i0 Consumer information

• "u#liie oerfished and threatened fish speies

• Eduate ommunit on the eonomi alue of aFuati and marine#iodiersit

• E'!' aordin! to a 2334 5orld 5ildlife +und stud, sea turtles are

worth more to loal ommunities alie than dead'

• .ea turtle tourism #rin!s in H more mone than the sale of turtleproduts e'!' meat, leather, and e!!s #rin!s in'

•

Eduatin! itiens a#out this issue ould inspire ommunities toprotet the turtles

! ii" E t $li h t f M i . t i & R


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!vii" Esta$lishment of Marine .anctuaries & Reserves

Sine 198, the 0DC: ?0nternational Dnion for Conser&ation of

:ature@ has helped to esta#lish a !lo#al sstem of marine protetedareas ?M")s@

%hese are areas of oean partiall proteted from human atiitiesan at as #reedin! sites for fish'

Reseres would #e losed to atiities suh as ommerial fishin!,dred!in!, and minin!, as well as to waste disposal

!viii" Protect By-catch


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!viii" Protect By-catch

•

Dse nets that allow esape of smaller fish

• Dse net esape deies for sea#irds and sea turtles

Fisheries WK 10(1).ppt

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