{"id":6014,"date":"2026-10-19T09:48:22","date_gmt":"2026-10-19T09:48:22","guid":{"rendered":"https:\/\/phd.hi.is\/doktorsvorn\/doktorsvorn-i-matvaelafraedi-stefan-thor-eysteinsson\/"},"modified":"2026-10-19T09:48:22","modified_gmt":"2026-10-19T09:48:22","slug":"doktorsvorn-i-matvaelafraedi-stefan-thor-eysteinsson","status":"publish","type":"phd_defence","link":"https:\/\/phd.hi.is\/en\/doktorsvorn\/doktorsvorn-i-matvaelafraedi-stefan-thor-eysteinsson\/","title":{"rendered":"Doktorsv\u00f6rn \u00ed matv\u00e6lafr\u00e6\u00f0i – Stef\u00e1n \u00de\u00f3r Eysteinsson"},"content":{"rendered":"
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Mi\u00f0vikudaginn 29. apr\u00edl ver Stef\u00e1n \u00de\u00f3r Eysteinsson doktorsritger\u00f0 s\u00edna \u00ed matv\u00e6lafr\u00e6\u00f0i vi\u00f0 Matv\u00e6la- og n\u00e6ringarfr\u00e6\u00f0ideild H\u00e1sk\u00f3la \u00cdslands. V\u00f6rninni ver\u00f0ur streymt:\u00a0https:\/\/livestream.com\/hi\/stefanthoreysteinsson<\/a><\/strong><\/p>\n

Ritger\u00f0in ber heiti\u00f0:\u00a0<\/p>\n

Eiginleikar rau\u00f0\u00e1tu (Calanus finmarchicus) og n\u00fdtingarm\u00f6guleikar \u00far hli\u00f0arstraumum fr\u00e1 vinnslu uppsj\u00e1varfiska<\/strong><\/p>\n

Andm\u00e6lendur eru dr. Ragnar Ludvig Olsen, pr\u00f3fessor vi\u00f0 Norges fiskerih\u00f6gskole, og dr. Hj\u00f6rleifur Einarsson, pr\u00f3fessor og deildarforma\u00f0ur au\u00f0lindadeildar vi\u00f0 H\u00e1sk\u00f3lann \u00e1 Akureyri.<\/p>\n

Lei\u00f0beinendur og umsj\u00f3narkennarar voru dr. Mar\u00eda Gu\u00f0j\u00f3nsd\u00f3ttir, pr\u00f3fessor vi\u00f0 Matv\u00e6la- og n\u00e6ringarfr\u00e6\u00f0ideild, dr. Sigurj\u00f3n Arason, pr\u00f3fessor vi\u00f0 Matv\u00e6la- og n\u00e6ringarfr\u00e6\u00f0ideild, og dr. Sigr\u00fan J\u00f3nasd\u00f3ttir, pr\u00f3fessor vi\u00f0 Danmarks Tekniske Universitet \u00ed Kaupmannah\u00f6fn. Auk \u00feeirra sat \u00ed doktorsnefnd dr. \u00c1st\u00fe\u00f3r G\u00edslason, pr\u00f3fessor hj\u00e1 Hafranns\u00f3knastofnun.<\/p>\n

\u00d3l\u00f6f Gu\u00f0n\u00fd Geirsd\u00f3ttir, pr\u00f3fessor og forseti Matv\u00e6la- og n\u00e6ringarfr\u00e6\u00f0ideildar, stj\u00f3rnar ath\u00f6fninni sem fer fram \u00ed H\u00e1t\u00ed\u00f0asal H\u00e1sk\u00f3la \u00cdslands og hefst kl. 13:30.<\/p>\n

\u00c1grip <\/strong>\u00a0<\/strong><\/p>\n

Aukin eftirspurn sj\u00e1varafur\u00f0a hefur s\u00ed\u00f0ustu 40 \u00e1r valdi\u00f0 aukinni ofvei\u00f0i fiskstofna \u00ed h\u00f6fum heimsins. \u00dev\u00ed er leita\u00f0 \u00ed auknum m\u00e6li a\u00f0 \u00f6\u00f0rum hr\u00e1efnum \u00far hafinu sem h\u00e6gt er a\u00f0 n\u00fdta me\u00f0 sj\u00e1lfb\u00e6rum h\u00e6tti. Hafa augu manna beinst a\u00f0 m\u00f6gulegri notkun \u00e1 d\u00fdrasvifi til framlei\u00f0slu \u00e1 n\u00e6ringarefnum eins og fj\u00f6l\u00f3mettu\u00f0u \u00f3mega-3 fitus\u00fdrunum eik\u00f3sapentaens\u00fdru (EPA, C20:5n3) og d\u00f3k\u00f3sahexaens\u00fdru (DHA, C22:6n3). Rau\u00f0\u00e1ta finnst \u00ed gr\u00ed\u00f0arlegu magni \u00ed hafinu \u00ed kringum \u00cdsland og er meginuppista\u00f0an \u00ed f\u00e6\u00f0u makr\u00edls sem ver\u00f0ur til \u00feess a\u00f0 miki\u00f0 magn af rau\u00f0\u00e1tu berst \u00e1 land vi\u00f0 vinnslu \u00e1 honum. Meginmarkmi\u00f0 ranns\u00f3knarinnar var a\u00f0 rannsaka eiginleika rau\u00f0\u00e1tu vi\u00f0 \u00cdsland og meta f\u00fdsileika \u00feess a\u00f0 n\u00fdta hana \u00feegar h\u00fan er veidd sem me\u00f0afli me\u00f0 uppsj\u00e1varfiski, s.s. makr\u00edl \u00e1 sj\u00e1lfb\u00e6ran h\u00e1tt. Fitusamsetning rau\u00f0\u00e1tu gerir hana t.d. ver\u00f0m\u00e6ta fyrir fiskiol\u00eduframlei\u00f0slu til manneldis, auk \u00feess sem h\u00fan er r\u00edk af astaxanth\u00edni og k\u00edt\u00edni. Me\u00f0 \u00fev\u00ed a\u00f0 sko\u00f0a fitus\u00fdrur sem l\u00edffr\u00e6\u00f0ileg sporefni (e. fatty acid trophic markers) var \u00e1\u00e6tla\u00f0 a\u00f0 rau\u00f0\u00e1ta v\u00e6ri mikilv\u00e6gasta einstaka d\u00fdrasvifstegundin \u00ed f\u00e6\u00f0u makr\u00edls. \u00c1tur\u00edkt hli\u00f0arhr\u00e1efni sem einangra m\u00e1 vi\u00f0 vinnslu \u00e1 makr\u00edl \u00ed landi einkenndist af h\u00e1u magni fj\u00f6l\u00f3mettu\u00f0u \u00f3mega-3 fitus\u00fdrana EPA og DHA. Fitust\u00f6\u00f0ugleiki og -g\u00e6\u00f0i \u00e1tur\u00edka hr\u00e1efnisins var mikill en var h\u00e1\u00f0ur t\u00edmanum fr\u00e1 vei\u00f0um a\u00f0 vinnslu. Rau\u00f0\u00e1ta sem berst \u00e1 land sem hli\u00f0arhr\u00e1efni hefur mikla m\u00f6guleika fyrir \u00e1framhaldandi vinnslu \u00ed afur\u00f0ir til manneldis \u00fear sem h\u00fan er r\u00edk af fj\u00f6l\u00f3mettu\u00f0u \u00f3mega-3 fitus\u00fdrunum EPA og DHA, auk astaxanth\u00edns og k\u00edt\u00edns.\u00a0\u00a0\u00a0<\/p>\n

Abstract<\/strong><\/p>\n

The demand for marine-derived nutrients has caused an increase in the overexploitation of fishery stocks in the past 40 years. These circumstances have led to a search for alternative sources of marine nutrients that can be sustainably utilized. One of the alternative sources now being utilized in the production of marine nutrients, such as the omega-3 polyunsaturated fatty acids (n-3 PUFA) eicosapentaenoic acid (EPA, C20:5n3) and docosahexaenoic acid (DHA, C22:6n3), is zooplankton. C. finmarchicus is the most abundant zooplankton in Icelandic waters and is the main prey of mackerel, and as a result, is present in large quantities in pelagic processing plants. The objective of the study was to examine C. finmarchicus in Icelandic waters and to estimate the feasibility of utilizing it when caught as a side-catch during pelagic fishing in a sustainable manner. The lipid composition of C. finmarchicus makes it valuable for oil production due to its high concentrations of EPA and DHA, astaxanthin, and chitin. Using the fatty acid trophic marker (FATM) method, C. finmarchicus was identified as an important food in the diet of mackerel in Icelandic waters. A zooplankton rich side-stream within the pelagic processing plant was characterized as having high amounts of EPA and DHA. The lipid stability of the zooplankton rich side-stream was relatively high but was highly dependent on the time that elapsed from catching until processing. Overall, the zooplankton rich side-stream was identified as a promising raw material capable of providing high amounts of EPA and DHA for human consumption.\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/p>\n

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

Stef\u00e1n \u00de\u00f3r Eysteinsson er f\u00e6ddur \u00ed Neskaupsta\u00f0 \u00e1ri\u00f0 1987. Hann lauk st\u00fadentspr\u00f3fi fr\u00e1 Verkmenntask\u00f3la Austurlands \u00e1ri\u00f0 2006, BA-pr\u00f3fi \u00ed l\u00edffr\u00e6\u00f0i \u00e1ri\u00f0 2011 fr\u00e1 Gonzaga University \u00ed Bandar\u00edkjunum og meistaragr\u00e1\u00f0u \u00ed matv\u00e6lafr\u00e6\u00f0i \u00e1ri\u00f0 2016 fr\u00e1 H\u00e1sk\u00f3la \u00cdslands. Stef\u00e1n hefur samhli\u00f0a doktorsn\u00e1minu starfa\u00f0 sem s\u00e9rfr\u00e6\u00f0ingur hj\u00e1 Mat\u00eds ohf. sem og sinnt kennslu og lei\u00f0beinslu nemenda vi\u00f0 Matv\u00e6la- og n\u00e6ringarfr\u00e6\u00f0ideild H\u00e1sk\u00f3la \u00cdslands. Fa\u00f0ir Stef\u00e1ns er Eysteinn \u00de\u00f3r Kristinsson og m\u00f3\u00f0ir er Hj\u00f6rd\u00eds Stef\u00e1nsd\u00f3ttir. Kona Stef\u00e1ns er Freyja Vi\u00f0arsd\u00f3ttir efnaverkfr\u00e6\u00f0ingur og sonur \u00feeirra er Gar\u00f0ar \u00de\u00f3r Stef\u00e1nsson, \u00feriggja \u00e1ra gamall.<\/p>\n<\/div><\/div>","protected":false},"featured_media":1258,"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":"2020-04-29T13:30:00+00:00","_phd_date_end":"2020-04-29T16:30:00+00:00","_phd_location":"A\u00f0albygging H\u00e1t\u00ed\u00f0asalur\/streymi","_phd_admission":"A\u00f0gangur \u00f3keypis","_phd_thesis_title":"Eiginleikar rau\u00f0\u00e1tu (Calanus finmarchicus) og n\u00fdtingarm\u00f6guleikar \u00far hli\u00f0arstraumum fr\u00e1 vinnslu uppsj\u00e1varfiska","_phd_source_url":"https:\/\/gamli.hi.is\/vidburdir\/doktorsvorn_i_matvaelafraedi_stefan_thor_eysteinsson","_phd_source_node_id":"337783","_phd_source_type":"vidburdir","_phd_member_id":245,"footnotes":""},"phd_school":[60,72],"phd_discipline":[74],"class_list":["post-6014","phd_defence","type-phd_defence","status-publish","has-post-thumbnail","hentry","phd_school-heilbrigdisvisindasvid","phd_school-matvaela-og-naeringafraedideild","phd_discipline-phd-i-matvaelafraedi"],"_links":{"self":[{"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/phd_defence\/6014","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\/6014\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/media\/1258"}],"wp:attachment":[{"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/media?parent=6014"}],"wp:term":[{"taxonomy":"phd_school","embeddable":true,"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/phd_school?post=6014"},{"taxonomy":"phd_discipline","embeddable":true,"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/phd_discipline?post=6014"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}