A High-Speed Fish Evisceration System (FES) for Bycatch and Underutilized Fish Stocks

Development of a high-speed and high-yield water-powered fish evisceration system (FES) to efficiently preprocess small fish and bycatch for producing minced fish meat is described. The concept of the system is propelling fish in a stream of water through an arrangement of cutting blades and brushes. Eviscerated fish are separated from the viscera and water stream in a dual screen rotary sieve. The FES processed head off fish, weighing 170–500 g, at the rate of 300 fish/min when used with an automatic heading machine. Yields of mince produced from walleye pollock, Theragra chalcogramma; and Pacific whiting, Merluccius productus; processed by the FES ranged between 43% and 58%. The maximum yield of minced muscle from fish weighing over 250 g was 52%, and the yield of 250 g was 58%. Test results indicated that surimi made from minced meat recovered from fish processed with the FES was comparable in quality to commercial grade surimi from conventional systems. Redesigned for commercial operation in the Faeroe Islands (Denmark), the system effectively processed North Atlantic blue whiting, Micromesistius poutassou, with an average weight of 110 g at a constant rate of 500–600 fish/min, producing deboned mince feeding a surimi processing line at a rate of 2.0 t/h. Yields of mince ranged from 55% to 63% from round fish. Surimi made from the blue whiting mince meat produced by the FES was comparable to surimi commercially produced from blue whiting by Norway and France and sold into European markets

Effects of Sustainable Diets containing Fish-Trim Waste, on Growth Performance of Juvenile Sablefish (Anopoploma fimbria)

A feeding trial was conducted to investigate the use of alternative fish feeds produced from fish-trim waste in high plant protein diets for juvenile sablefish (Anopoploma fimbria). Fish meal in the control diet (CD) was replaced in the experimental diets by low molecular weight hydrolysate (LMWH) protein derived from Pacific whiting (Merluccius productus) processing waste, or by Atlantic salmon (Salmo salar) processing trim (ST), which was incorporated into the feed with an experimental heated ball mill. The feeding trial was conducted in an indoor recirculating seawater system and each feed was randomly assigned to triplicate groups of 50 fish (average initial body weight of 57.5 g). The results showed that compared to the control diet, the diets containing LMWH or ST significantly increased feed consumption and fish weight gain. The ST group showed a significantly higher weight gain than the LMWH group. The ST feed, but not the LMWH feed, had a significantly lower feed conversion ratio than the CD feed. The ST feed increased lipid retention efficiency and lipid content in whole body tissue. These results demonstrate that salmon fish trim waste and enzyme hydrolyzed whiting trim in high plant protein diets can increase the performance in sablefish

Fish larval nutrition and feed formulation: knowledge gaps and bottlenecks for advances in larval rearing

Despite considerable progress in recent years, many questions regarding fish larval nutrition remain largely unanswered, and several research avenues remain open. A holistic understanding of the supply line of nutrients is important for developing diets for use in larval culture and for the adaptation of rearing conditions that meet the larval requirements for the optimal presentation of food organisms and/or microdiets. The aim of the present review is to revise the state of the art and to pinpoint the gaps in knowledge regarding larval nutritional requirements, the nutritional value of live feeds and challenges and opportunities in the development of formulated larval diets.Norwegian Ministry of Fisheries; Research Council of Norway [CODE-199482, GutFeeling-190019]; Spanish Ministry of Science and Innovation MICINN + FEDER/ERDF [AGL2007-64450-C02-01, CSD2007-0002]; project HYDRAA [PTDC/MAR/71685/2006]; Fundacao para a Ciencia e a Tecnologia (FCT), Portugal; FEDER; EC [LIFECYCLE- 222719]; EU RTD [FA0801]info:eu-repo/semantics/publishedVersio

Homogeneous-Like Generalized Cubic Systems

We consider properties and center conditions for plane polynomial systems of the forms x˙=-y-p1(x,y)-p2(x,y), y˙=x+q1(x,y)+q2(x,y) where p1, q1 and p2, q2 are polynomials of degrees n and 2n-1, respectively, for integers n≥2. We restrict our attention to those systems for which yp2(x,y)+xq2(x,y)=0. In this case the system can be transformed to a trigonometric Abel equation which is similar in form to the one obtained for homogeneous systems (p2=q2=0). From this we show that any center condition of a homogeneous system for a given n can be transformed to a center condition of the corresponding generalized cubic system and we use a similar idea to obtain center conditions for several other related systems. As in the case of the homogeneous system, these systems can also be transformed to Abel equations having rational coefficients and we briefly discuss an application of this to a particular Abel equation

Implementering av Infarten : Vägverkets nya intranät

Vi har på uppdrag från Vägverket undersökt hur väl implementeringen av det nya intranätet, Infarten, har genomförts och mottagits av berörd personal på lokalkontoret i Karlstad. Infartens övergripande mål är att vara en del av chefernas och medarbetarnas dagliga arbete samt fungera som ett verktyg för att söka information. Intranätet ska sprida aktuella nyheter, som alla inom organisationen ska kunna ta del av. Anledningen till att Vägverket valde att vidareutveckla Infarten, från regionala intranät till ett intranät för samtliga regioner, var att de upplevde svårigheter och problem med en icke fungerande uppföljning och dubbellagring av information. För att ta reda på hur väl Infarten fungerar i det dagliga arbetet i verksamheten genomförde vi en kvalitativ undersökning bland medarbetarna på lokalkontoret i Karlstad. I de intervjuer vi gjorde, studerade vi medarbetarnas användning av Infarten i sina dagliga arbeten och även deras egna uppfattningar om Infartens uppbyggnad. Resultatet visade att medarbetarna hade användning av Infarten, de uppgav att de inte skulle vilja vara utan Infarten. Vi såg ett mönster som visade att respondenterna endast använde sig av vissa delar av Infarten, de delar de behövde för att klara av sina arbetsuppgifter. Vidare uppgav respondenterna att de upplevde ett problem med för mycket information på Infarten. De tyckte att det många gånger var svårt att hitta relevant information