{"id":6100,"date":"2026-10-19T09:48:28","date_gmt":"2026-10-19T09:48:28","guid":{"rendered":"https:\/\/phd.hi.is\/doktorsvorn\/doktorsvorn-i-vistfraedilikonum-vianny-natugonza\/"},"modified":"2026-10-19T09:48:28","modified_gmt":"2026-10-19T09:48:28","slug":"doktorsvorn-i-vistfraedilikonum-vianny-natugonza","status":"publish","type":"phd_defence","link":"https:\/\/phd.hi.is\/en\/doktorsvorn\/doktorsvorn-i-vistfraedilikonum-vianny-natugonza\/","title":{"rendered":"Doktorsv\u00f6rn \u00ed vistfr\u00e6\u00f0il\u00edk\u00f6num – Vianny Natugonza"},"content":{"rendered":"
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V\u00f6rninni ver\u00f0ur streymt:\u00a0https:\/\/livestream.com\/hi\/viannynatugonza<\/a><\/strong><\/p>\n

Doktorsefni:<\/strong>\u00a0Vianny Natugonza<\/p>\n

Heiti ritger\u00f0ar:<\/strong>\u00a0Samanbur\u00f0argreining \u00e1 vistkerfisl\u00edk\u00f6num af Viktor\u00eduvatni (Austur-Afr\u00edku) til a\u00f0 skilja \u00e1hrif fl\u00e6kjustigs og gagna\u00f3vissu \u00e1 mat \u00e1 stefnu.<\/p>\n

Andm\u00e6lendur:
<\/strong>Dr. Johanna J. Heymans, pr\u00f3fessor vi\u00f0 European Marine Board, Belg\u00edu
Dr. Ian G. Cowx, pr\u00f3fessor vi\u00f0 H\u00e1sk\u00f3lann \u00ed Hull, Bretlandi<\/p>\n

Lei\u00f0beinandi:<\/strong>\u00a0Dr. Gunnar Stef\u00e1nsson, pr\u00f3fessor vi\u00f0 Raunv\u00edsindadeild H\u00e1sk\u00f3la \u00cdslands<\/p>\n

Einnig \u00ed doktorsnefnd:\u00a0<\/strong>Dr. Erla Sturlud\u00f3ttir, lektor vi\u00f0 Landb\u00fana\u00f0arh\u00e1sk\u00f3la \u00cdslands
Dr. Chrispine Nyamweya, v\u00edsindama\u00f0ur vi\u00f0 Kenya Marine and Fisheries Research Institute (KMFRI), Kenya
Dr. Tumi T\u00f3masson; s\u00e9rfr\u00e6\u00f0ingur hj\u00e1 Hafranns\u00f3knastofnun<\/p>\n

Doktorsv\u00f6rn st\u00fdrir:<\/strong>\u00a0Dr. Oddur Ing\u00f3lfsson, pr\u00f3fessor og deildarforseti Raunv\u00edsindadeildar H\u00e1sk\u00f3la \u00cdslands.<\/p>\n

\u00c1grip:\u00a0
<\/strong>Notkun vistkerfisn\u00e1lgunar vi\u00f0 stj\u00f3rn fiskvei\u00f0a \u00e1 undanf\u00f6rnum \u00e1rum hefur breikka\u00f0 svi\u00f0 fiskvei\u00f0istj\u00f3rnunar me\u00f0 \u00fev\u00ed a\u00f0 \u00e1kvar\u00f0anir mi\u00f0ast ekki einv\u00f6r\u00f0ungu vi\u00f0 h\u00e1m\u00f6rkun heildarafla e\u00f0a afraksturs heldur er einnig teki\u00f0 tillit til f\u00e9lagslegra og hagr\u00e6nna \u00fe\u00e1tta vi\u00f0 n\u00fdtingu lifandi au\u00f0linda sj\u00e1var. Vistkerfisl\u00edk\u00f6n draga saman fj\u00f6lbreytt uppl\u00fdsingas\u00f6fn um hva\u00f0 r\u00e6\u00f0ur vistkerfisbreytingum og gefa \u00feannig samr\u00e6mt heildarmat \u00e1 \u00e1standi og \u00fe\u00e1 r\u00e1\u00f0gj\u00f6f sem \u00fearf a\u00f0 nota fyrir vistkerfisn\u00e1lgun vi\u00f0 stj\u00f3rn fiskvei\u00f0a (ecosystem-based fisheries management, EBFM). \u00d3l\u00edk vistkerfisl\u00edk\u00f6n geta hins vegar gefi\u00f0 talsvert \u00f3l\u00edkar sp\u00e1r um \u00fer\u00f3un. Sl\u00edk l\u00edkan-\u00f3vissa er talsver\u00f0 hindrun vi\u00f0 notkun \u00feessara l\u00edkana vi\u00f0 EBMF. \u00de\u00e6r ranns\u00f3knir sem h\u00e9r eru kynntar r\u00fdna \u00ed \u00e1hrif fl\u00e6kjustigs l\u00edkana og \u00f3vissu \u00ed g\u00f6gnum \u00e1 \u00e1kvar\u00f0anir um au\u00f0lindan\u00fdtingu \u00ed lj\u00f3si EBFM og eru ni\u00f0urst\u00f6\u00f0ur kynntar \u00ed sex greinum.<\/p>\n

\u00cd grein I er gefi\u00f0 yfirlit um notkun vistkerfisl\u00edkana \u00e1 st\u00f3ru v\u00f6tnin \u00ed Afr\u00edku (African Great Lakes, AGL), mest me\u00f0 „Ecopath with Ecosim“ (EwE) og Atlantis. Markmi\u00f0i\u00f0 h\u00e9r er a\u00f0 skila st\u00f6\u00f0u og framf\u00f6rum \u00ed ger\u00f0 vistkerfisl\u00edkana fyrir v\u00f6tn \u00e1 hitabeltissv\u00e6\u00f0um og aflei\u00f0ingar fyrir fiskiranns\u00f3knir og au\u00f0lindan\u00fdtingu. Ni\u00f0urst\u00f6\u00f0urnar s\u00fdna a\u00f0 ranns\u00f3knir \u00e1 svi\u00f0i vistkerfisl\u00edkana eru ekki mj\u00f6g virkar fyrir ferskvatnssv\u00e6\u00f0i Afr\u00edku og r\u00e1\u00f0gj\u00f6f byggir oftast \u00e1 eins-stofns a\u00f0fer\u00f0um.<\/p>\n

Grein II l\u00fdsir \u00fer\u00f3un st\u00f6\u00f0ul\u00edkans (Ecopath) fyrir Viktor\u00eduvatn, b\u00e6\u00f0i mi\u00f0a\u00f0 vi\u00f0 \u00e1stand \u00ed n\u00fat\u00edma (2014) og endurmat eldri Ecopath l\u00edkana, fyrir \u00e1stand upp \u00far 1970 og upp \u00far 1980. Markmi\u00f0i\u00f0 h\u00e9r er a\u00f0 rannsaka \u00fer\u00f3un f\u00e6\u00f0uvefsins vi\u00f0 r\u00f6skun vistkerfisins, s\u00e9rstaklega vegna innlei\u00f0ingar n\u00fdrra tegunda. Ni\u00f0urst\u00f6\u00f0urnar s\u00fdna a\u00f0 f\u00e6\u00f0uvefurinn er einfaldur, me\u00f0 f\u00e1um tengingum og mikilli endurvinnslu l\u00edfmassa, sem g\u00e6ti bent til \u00feess a\u00f0 samsetning vistkerfisins hafi ekki n\u00e1\u00f0 \u00ed upprunalegt horf eftir breytingar \u00e1 n\u00edunda \u00e1ratugnum. \u00cd f\u00e6\u00f0uvefjunum eru n\u00fa\u00a0 breyttir ferlar orkuflutninga og tegundah\u00f3par sem hafa a\u00f0lagast breyttum a\u00f0st\u00e6\u00f0um og ni\u00f0ursta\u00f0an g\u00e6ti \u00fev\u00ed veri\u00f0 a\u00f0 vatni\u00f0 muni ekki leita aftur \u00ed fyrra horf.<\/p>\n

Grein III ber saman s\u00f6gulegt EwE l\u00edkan sem fellt er a\u00f0 eldri t\u00edmara\u00f0arg\u00f6gnum vi\u00f0 jafnst\u00f6\u00f0ul\u00edkan lagt a\u00f0 n\u00fdrri g\u00f6gnum. Tilgangurinn er a\u00f0 skilja \u00e1rei\u00f0anleika jafnst\u00f6\u00f0ul\u00edkana sem ekki nota formlega a\u00f0l\u00f6gun a\u00f0 g\u00f6gnum \u00feegar \u00feau eru notu\u00f0 til a\u00f0 sp\u00e1 fyrir um aflei\u00f0ingar stj\u00f3rnvalds\u00e1kvar\u00f0ana. L\u00edk\u00f6nin lei\u00f0a til \u00f3l\u00edkra ni\u00f0ursta\u00f0na en munurinn minnkar ef l\u00edfmassabreytingar \u00ed n\u00fat\u00edmal\u00edkaninu eru stilltar \u00e1 a\u00f0 endurspegla m\u00e6ldar hreyfingar \u00ed l\u00edfmassa.<\/p>\n

Grein IV ber saman EwE og Atlantis l\u00edk\u00f6n til a\u00f0 auka skilning \u00e1 hvernig l\u00edkanger\u00f0, fl\u00e6kjustig og forsendur hafa \u00e1hrif \u00e1 mat \u00e1 stj\u00f3rnvaldsa\u00f0ger\u00f0um. \u00de\u00f3tt verulegur munur s\u00e9 \u00e1 sp\u00e1 um aflei\u00f0ingar fyrir staka h\u00f3pa \u00ed vistkerfinu gefa l\u00edk\u00f6nin svipa\u00f0a heildars\u00fdn. \u00deessi ni\u00f0ursta\u00f0a bendir til \u00feess a\u00f0 vistkerfisl\u00edk\u00f6n sem hafa ger\u00f3l\u00edka innri byggingu geta gefi\u00f0 raunh\u00e6fa yfirlitsmynd og megindlega r\u00e1\u00f0gj\u00f6f eins og \u00fearf gjarnan fyrir EBFM.<\/p>\n

Grein V fjallar um mat \u00e1 f\u00e9lagslegum og efnahagslegum \u00e1hrifum stj\u00f3rnunara\u00f0ger\u00f0a me\u00f0 Atlantis og EwE. Markmi\u00f0i\u00f0 h\u00e9r er a\u00f0 skilja betur hlutfallslega \u00e1h\u00e6ttu og \u00e1bata \u00feegar \u00f3l\u00edkum markmi\u00f0um fiskvei\u00f0istj\u00f3rnunar er beitt \u00e1 fiskvei\u00f0ar \u00fear sem eru f\u00e1ir m\u00f6guleikar \u00e1 b\u00e6ttum l\u00edfsg\u00e6\u00f0um. Ni\u00f0urst\u00f6\u00f0urnar s\u00fdna a\u00f0 h\u00e1m\u00f6rkun hagna\u00f0ar er \u00ed betra samr\u00e6mi vi\u00f0 markmi\u00f0 um sj\u00e1lfb\u00e6rni og vi\u00f0gang heldur en f\u00e6st me\u00f0 h\u00e1m\u00f6rkun afla (e\u00f0a atvinnu). Hins vegar lei\u00f0ir h\u00e1m\u00f6rkun hagtalna me\u00f0 skor\u00f0um \u00e1 samsetningu vistkerfis til kr\u00f6fu um minna \u00fathald allra flota. \u00deessar ni\u00f0urst\u00f6\u00f0ur undirstrika mikilv\u00e6gi \u00feess a\u00f0 skilgreina vel helstu markmi\u00f0 fiskvei\u00f0istj\u00f3rnunar og a\u00f0 kynna \u00e1hrif hennar \u00e1 hli\u00f0armarkmi\u00f0 \u00fev\u00ed ekki er h\u00e6gt a\u00f0 gera r\u00e1\u00f0 fyrir samt\u00edmah\u00e1m\u00f6rkun margra markmi\u00f0a.<\/p>\n

Grein VI metur breytileika \u00ed vei\u00f0imynstri og s\u00f3kn \u00ed t\u00edma og r\u00fami \u00ed samhengi vi\u00f0 l\u00edffr\u00e6\u00f0ilega framlei\u00f0ni tegunda og tegundah\u00f3pa. Ni\u00f0urst\u00f6\u00f0urnar s\u00fdna a\u00f0 n\u00fdting er skekkt \u00ed \u00e1ttina a\u00f0 \u00fev\u00ed a\u00f0 n\u00fdta tegundah\u00f3pa me\u00f0 l\u00e1ga framlei\u00f0ni, sem er \u00ed samr\u00e6mi vi\u00f0 m\u00e6ldar breytingar \u00ed tegundasamsetningu og minni me\u00f0allengdar helstu efnahagslega mikilv\u00e6gra fisktegunda, til d\u00e6mis N\u00edlarkarfa (Lates niloticus) og fleiri tegunda (s.s. Oreochromis niloticus). Frekari ranns\u00f3knir \u00fearf til a\u00f0 meta hagkv\u00e6mni tilf\u00e6rslu \u00ed \u00e1tt til a\u00f0fer\u00f0ar jafnrar s\u00f3knar (balanced harvest strategy) \u00fear sem s\u00f3kn er sett sem hlutfall af framlei\u00f0slu tegundar.<\/p>\n

Ni\u00f0ursta\u00f0an er s\u00fa a\u00f0 vistkerfisl\u00edk\u00f6n eru mikilv\u00e6gur hluti verkf\u00e6rakassans vi\u00f0 \u00e1kvar\u00f0anat\u00f6ku. \u00deau geta stutt vi\u00f0 beitingu vistkerfisn\u00e1lgunar vi\u00f0 fiskvei\u00f0istj\u00f3rnun en afar \u00e6skilegt er a\u00f0 beita fj\u00f6l\u00fe\u00e6ttu safni vistkerfisl\u00edkana til a\u00f0 pr\u00f3fa og \u00feekkja bjaga og takmarkanir mismunandi a\u00f0fer\u00f0a. \u00deessi ritger\u00f0 leggur \u00e1herslu \u00e1 fiskvei\u00f0ar sem tengjast vel \u00feekktum r\u00e1nfiskum eins og N\u00edlarkarfa og lykilbr\u00e1\u00f0 hans (haplochromines). Auknar fj\u00f6ll\u00edkanahermanir g\u00e6tu reynst vel til a\u00f0 bera saman mat \u00f3l\u00edkra l\u00edkana \u00e1 v\u00edxlverkandi \u00e1hrif breyttrar s\u00f3knar \u00ed a\u00f0rar tegundir og h\u00f3pa.<\/p>\n

Um doktorsefni\u00f0:<\/strong><\/p>\n

Vianny Natugonza f\u00e6ddist \u00e1ri\u00f0 1987 og \u00f3lst upp \u00ed Kitagwenda h\u00e9ra\u00f0i, Vestur-\u00daganda. Hann h\u00f3f n\u00e1m vi\u00f0 Makerere-h\u00e1sk\u00f3lann \u00ed Kampala, \u00fear sem hann lauk BSc-gr\u00e1\u00f0u \u00ed sj\u00e1var\u00fatvegs- og fiskeldisfr\u00e6\u00f0um \u00e1ri\u00f0 2011 og MSc-gr\u00e1\u00f0u \u00ed d\u00fdrafr\u00e6\u00f0i \u00e1ri\u00f0 2015.<\/p>\n

Vianny fluttist til Belg\u00edu \u00e1ri\u00f0 2015 og starfa\u00f0i vi\u00f0 hi\u00f0 Konunglega safn Mi\u00f0-Afr\u00edkur\u00edkjanna. Hann flutti s\u00ed\u00f0ar til \u00cdslands og starfa\u00f0i vi\u00f0 mat fiskistofna hj\u00e1 Hafranns\u00f3knastofnun og vi\u00f0 H\u00e1sk\u00f3lann \u00e1 Akureyri.<\/p>\n

\u00c1ri\u00f0 2017 h\u00f3f Vianny doktorsn\u00e1m vi\u00f0 H\u00e1sk\u00f3la \u00cdslands. Hann starfar n\u00fa hj\u00e1 Ranns\u00f3knarstofnun fiski\u00f0na\u00f0arins \u00ed \u00daganda og b\u00fdr \u00ed Jinja \u00e1samt eiginkonu sinni, Sylvia Tukwasibwe, og tveimur b\u00f6rnum, Esther Lwamubito og Adrian Ampurira Lubito.<\/p>\n<\/div><\/div>","protected":false},"featured_media":1881,"template":"","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"_phd_date_start":"2020-06-18T13:00:00+00:00","_phd_date_end":"2020-06-18T15:00:00+00:00","_phd_location":"","_phd_admission":"A\u00f0gangur \u00f3keypis","_phd_thesis_title":"Samanbur\u00f0argreining \u00e1 vistkerfisl\u00edk\u00f6num af Viktor\u00eduvatni (Austur-Afr\u00edku) til a\u00f0 skilja \u00e1hrif fl\u00e6kjustigs og gagna\u00f3vissu \u00e1 mat \u00e1 stefnu","_phd_source_url":"https:\/\/gamli.hi.is\/vidburdir\/doktorsvorn_i_vistfraedilikonum_vianny_natugonza","_phd_source_node_id":"343907","_phd_source_type":"vidburdir","_phd_member_id":508,"footnotes":""},"phd_school":[101,93],"phd_discipline":[107],"class_list":["post-6100","phd_defence","type-phd_defence","status-publish","has-post-thumbnail","hentry","phd_school-raunvisindadeild","phd_school-verkfraedi-og-natturuvisindasvid","phd_discipline-phd-i-vistfraedilikonum"],"_links":{"self":[{"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/phd_defence\/6100","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/phd_defence"}],"about":[{"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/types\/phd_defence"}],"version-history":[{"count":0,"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/phd_defence\/6100\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/media\/1881"}],"wp:attachment":[{"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/media?parent=6100"}],"wp:term":[{"taxonomy":"phd_school","embeddable":true,"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/phd_school?post=6100"},{"taxonomy":"phd_discipline","embeddable":true,"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/phd_discipline?post=6100"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}