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Juan Fernandez Islands (Chile) Living Marine Resources and Fishery PDF

121 Pages·2007·4.45 MB·English
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Juan Fernandez Islands (Chile) Living Marine Resources and Fishery Perspective Marine Resource Management Program School of Oceanography Oregon State University in partial fulfillment of the requirements for the degree of INDEX - Acknowledgements - Introduction - General information about the islands - Oceanographic conditions of the region - Present fishery - Discussion - Appendix 1.- List of known species found around Juan Fernandez Islands 2.- Research program proposed to execute in the islands 3.- Robinson Crusoe's story - Bibliography ACKNOWLEDGEM=TS I take pleasure at this time in acknowledging the hel p given to me by several people. Specifically, I must say thanks to Mrs. Amelia Nishik.,-TP, Mrs. Maxine Hilfiker, Miss Anne Hoch'oerg and Mr. Rocco Falotico who helped me put this paper closer to ShakeE peare's lang-uage. special atteton has been given to the aeoently, studies dealing with marine species. This is due principally ,' also to to the scarce knowledge that we have about them 2n the fishing interest generated by the relative abundance of • some of them. .carried out in Chile. At the present, the studies fishery to research biological and primly have been conducted coastal organisms.a the other r problems associated. with nea af hand, studies on the oceanic species, since they are not fected by exploitation have been delayed, and the inform,ation actually available is limited. y years • few species have been ext)olted for man A South-St A n the around several Chilean islands In the particular case of the Juan Fernandez islands, the 1Drin- the "lobster of Juan Fernandez" deal fisheries are related to big demersal fish called "bacalao and to a (Jasus frontalis) (ectoria(olvorion) oxigaa2ios). Or Qal mcn de roca" for their history also fs-TeUS Those islands of theme 50otti3h sailor lived on one and..principally.because solitary and. voluntary con- years and four months in for four 1 Lefoe wrote his book "Ho- Danie fineent (1704-1709). Later, the story became rapidly known Cru,;oe" throu gh which binson is officially cal- f the islands lfT, one around the world. so led '-'_obinson Crusoe and the other � rinero 3- 11k.ir'k in honor vyte_vi. 2 1 of the oricinal maroon (sea Appendix 3 i .� the flora and fauna of these islands are of extraordinary scientific inte- rest. It is imoortant to study the o� the islands and the relationship of its flora and fauna with organisms from other biogeographical regions. Also important to consider � the hu-nan inter- vention on the islands since their d i scoy ery in 15T4,. t lest one s pecies of the authoctonic flora was extLnlished ("Sanda- lo" or "ber g amot mint") and the Juan Fernandez fur seal (r- cto'ohoca (Arctoce phalus) philiop ii) was considered for a lon time extinct, due to the cruel and uncontrolled huntin g by American sailors, during the XVIII and All centuries. All these characteristics motivated the Centro de Investig. aciones del Mar (OIMAH) of the Catholic University of Valparaiso (Chile) to begin, in. 1971, , a research program. This research was focused. on the oceanographic conditions of this re g ion and the fishing activity wh:i:chhich is at pres ent the principal occupation of the population on the islands. The results of these studies have stimulated the scientific inte- rest of this oceanic region. This pacer is en attempt to summarize our actual Knowledge about the marine resources available in the area. it also analizes the situation of the fishery and the princi- -nal as pects involved. in a possible Plan for an in e..;-ral ries develor,ment of the Oceanic re .;7ion around the islands. This r)lan could maintain the� tradition of artisanal fishery by considering their unique characteristics. GENEd..::L INFOTTOM ABOUT THE SLIITJS The Juan Fernandez Islands are located at 330 40' S and approximately 360 miles from the South _Lmerican continent (79° 81 0 W). This group of islands include obin- son Crusoe I. (formerly called ias a Tierra, with 93 2 and 950 m as maximun height); Santa Clara I. (3 2,2 and 375 m ; and several small barren islands (El ierduo, El 'lludo, Los Chamelos, and Juanango). Ninety� miles west of these is- lands there is another island, iarnero Selkirk (form4ly mas Afuera, 82 Km2 and 1835 m height). Accordinyto BRUGGEN ( 1950), the nature of this grout of islands is volcanic, formed probably cParing the. ,J per Tertiary by the to p of airlolder ride 7,Thich -,as separated from the continent, between ikrauco and M gallanes. urinx the Oligocene, this ridge descended underwater and the islands were formed by later eruptions. The Juan Fernandez rid.:_=,-e is ori f -ri+- ecL�perpendi- cular to the Chilean coast and is � miles lon (Figure 1). The tops of, some mountains are very close to the surface. Lenths of only 300 to 400 meters have been found on some of them, This is the case of the O'Higgins Sea mount, only 40 miles west of Val paraiso. The islands constitute the emerged seamount peaks of this ridge. LAJ:i.AZAGI and "- SACKS (1976) pointed out that there is a remarkable correlation between the location of the oceanic Juan Fernandez ridge and the transition from the Chilean flat seismic zone (between about lat 27° and 33° s) to the steeper seismic zone in southern Chile. They said also that active vol- canoes are located on the Juan Fernandez ridge. So the ridge intersects the Chilean coastline near lat 33° 5, where the coastline has a major bend and where the Feru-Chile trench becomes increasingly sediment filled.i ,ioreover, the inland pro- jection of the ridge beneath the South American Plate closely coincides with the northern limit of the active volcanoes of Southern Chile as well as with the end of the Central Valley of Chile. In this case, the authors suggest that the Juan Fer- nandez ridge forms a ?one of weakness in the Nazca plate along which the plate tears as it descends beneath the South Ameri- can plate (Figure 2). Regarding the Presence of Juan Fernandez ridge in this area, some s pecific research was carried out during the Expeditions idarchile VIII, IX and X. The princi pal objecti- ves of this research were to increase our knowledge about its bathymetry, the influence of the ridge in the eneral oceano- graphic conditions and what kind of living resources are pre- sent. During the expedition i,jarchile IX, three fishing stations with bottom longlines and tra ps were carried. out on the top of the seamount East of the Juan Fernandez Islands. A fouth station was established. on U'digginSeamount. The sampled de pths were between 267 m and 470 m. The catch was composed of four species of the Telestomi class: "bacal ao (Hectoria (Polv prion) oxi geneios), Conger s p ., Gilbertia s p . and. Mora pacifica, and three species of Elasmobranchii class: Etmos- terus sp., EtmosteruS granulosus and Somniosus s p . Catch rates were between 29.5 and 35.4 fish per 100 hooks (CEHDA, 1977) The traps caught principally "jaibas rdgantes" (red crab), Geryon duinauedens, but the results of this fishing survey still have not been published- However, the research proved that Gn the ridge there are no lobsters present due nerhams to the greater depth. around. 450 miles north of t_t__e Juan iiernande7 lands exist another Froup of islads ramed. the DesventuradaS Islands. This other grou p , 400 miles from t � chilec.n coast, is forted by the SP:o Pelix and Sar limbrosio islands-both with very difficult access and without water - plus the small barren islands Gonzalez and the Cathedral of i:eterborough. These is- lands are uninhabited, -but sometimes fishermen from the Juan Fernandez Islands come to fish for "bacalao and lobsters which are in great abundance and usually bigger than in the other group of islands. This is due to the scarce fishing ac-,. tivity in this area and the problems of establishing a fishing base in these islands. The region where the islands are located is charac- terized by a subtrocical climate. In this area, rains are common in all the seasons (Table I). among the meteorological parame- '------7-172 ---Z- /1 -\, \\ „_____■_,--- GA RL.I‘F`,PT4,00s .� .� • _ __Am_ I� I Illi� . . f-------/- -■.,., 71 _ .. Jca._ • ._c_• . 3000� . - 0° 3000 -_____tp -::- .� . - /Ns .1.-- •� .-� .� .� / - (cp "D R-A/sPEA. ',OS PERU 00 u6,, - le s -----2 ------- Q. ..,"" . _ , ,.,: -,-� F, .3.-,-'� " ---' BASIN - \\I .-O--'-C---l) ----- mo 3 (-3 C1' - 1:7 � 01P' '''� Al,. tr: ;. 20°�-I il q vi\-,i,\L.)4.- o,,i,ilII � f, _ OM> CHIL Z _ J 4� .13-SCBBCCASIN� u( .3, IsI� � l•-.:.. cr II _ 3600 _ o . o - .I.uis.t.i. - , - 0r‘ _.� c_i_.\_\-51-� \5 ' � %%� � 'nt o1o IE cC S.. D L ),,ACN°-D--S-'.6 Z- -77 .� •C -1 o/x-7 - j °V ail . .....„ II 0I I \ ro-) 5,...tp.vk,\_!- \„ 0- - 40° - • 1 1 "i 3600-- _ I t I t ,� I t i� isl'• . I 120" HO' 100 ° 903� 80° 70°W 5 4 Figure 2. Geological features of the South East Pacific, showing the Juan Fernandez ridge.

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