Fishery management as exact science

The main objective in research on sustainable fishery management is to understand the effects of fisheries on the resources and predict the Maximal Sustainable Yield. The von Bertalanffy growth model, commonly used in stock assessment, is suboptimal for the calculation of yield, because it cannot be integrated to omit time from the equation. Here, we present a new model to be used as the scientific basis to calculate yield and provide advices for optimal ecological harvesting strategies. The model builds on the principle of exact science and utilizes population measurements from scientific acoustic trawl surveys as input in a real population dynamical model. The model expands the theory of relativity to include the transition of biomass into energy and will improve simulation models used in fisheries science

A new model for simulating growth in fish

A real dynamic population model calculates change in population sizes indepen- dent of time. The Beverton & Holt (B&H) model commonly used in fish assessment includes the von Bertalanffy growth function which has age or accumulated time as an independent variable. As a result the B&H model has to assume constant fish growth. However, growth in fish is highly variable depending on food availability and environmental conditions.We propose a new growth model where the length increment of fish living under constant conditions and unlimited food supply, de- creases linearly with increasing fish length until it reaches zero at a maximal fish length. The model is independent of time and includes a term which accounts for the environmental variation. In the present study, the model was validated in ze- brafish held at constant conditions. There was a good fit of the model to data on ob- served growth in Norwegian spring spawning herring, capelin from the Barents Sea, North Sea herring and in farmed coastal cod. Growth data fromWalleye Pollock from the Eastern Bering Sea and blue whiting from the Norwegian Sea also fitted reasonably well to the model, whereas data from cod from the North Sea showed a good fit to the model only above a length of 70 cm. Cod from the Barents Sea did not grow according to the model. The last results can be explained by environmental factors and variable food availability in the time under study. The model implicates that the efficiency of energy conversion from food decreases as the individual animal approaches its maximal length and is postulated to represent a natural law of fish growth

Data Collection & ABA Therapy with Disability & Child Welfare

This proposed intervention explains the need for both data collection on children with developmental disabilities in child welfare and how it will benefit future work, as well as a proposal of an evidence-based intervention using Applied Behavioral Analysis (ABA) therapy for children with developmental disabilities. The goal is to work towards improved outcomes for children with developmental disabilities and to create equity for these children in the child welfare system. The population focus of this project are children with developmental disabilities, specifically, children who are involved with the child welfare system. This will also include biological family and foster family with in-home services in order to either stabilize placement, prevent placement, or facilitate the child returning home. The theoretical frameworks at the bases of this intervention are intersectional feminist theory and anti-oppressive social work theory

Why do jellyfish bloom in Norwegian waters and what can be done to recover the ecosystems in the North Sea and on the Norwegian coast?

Disclaimer: This article was prepared by Johannes Hamre in his personal capacity. The opinions expressed in this article are the author's own and do not reflect the views of the Institute of Marine ResearchThe ecosystems with their relationships between fish species and stocks, have been established by evolution for millions of years, but only during the last 50 years, the ecosystems in the North Sea and along the Norwegian coast have been changed fundamentally by fisheries. The North Sea mackerel stock has been depleted and its feeding grounds have been taken over by the Western mackerel which spawns west of Ireland. This stock is now very rich in numbers and distributes into the North sea, the Norwegian sea and the western Barents Sea. If the stock of Western mackerel is allowed to grow further it may outcompete many of the other fish stocks in the area. 50 years ago there was a large stock of sandeel, which spawned in the North Sea and on the Norwegian coast. Sandeel juveniles was an important food source for a wide range of species, including sea mammals and birds. The fact that this stock has also been overfished, may explain many of the changes seen in the ecosystem on the west coast of Norway, for example a large reduction in the populations of sea birds. There are indications that ecosystems shift to sustain jellyfish blooms in response to depletion of forage fish stocks. This was registered in Namibia in the 1990’s, where the pilchard stock was decimated and the biomass of jellyfish was overwhelming. On the west-coast of Norway, there are now frequent blooms of jellyfish, yet another indication that sandeel, a key species in the transfer of nutrients from zooplankton to higher trophic levels in the area, has been depleted. In this paper, I give a description of the situation and some suggested measures that should be taken in fisheries management.

Kan bruken av flerbestandsmodellen Systmod endre vårt syn på forvaltningen av torskebestanden i Barentshavet?

Systmod er en konseptuell simuleringsmodell for biomasseproduksjonen i bestandene av lodde, sild og torsk i Barentshavet. Hver bestand er modellert med enbestandsmodeller, hvor bestandsinteraksjonene er klimarelatert og ivaretatt som vekst (mattilbud) og dødelighet. Parametrene er bestemt ved tuning mot relevante data fra perioden 1982-2005. Konseptet betinger at ungsildbestanden påvirker loddebestanden som er torskens viktigste byttedyr. Modellkjøring viser at de viktigste interaksjonene for utbytte av torsk er virkningen av sildens beiting på loddelarver, torskebestandens beiting på kjønnsmoden lodde og på eget avkom (kannibalisme). Sterke sildeårsklasser reduserer rekrutteringen til loddebestanden. Det reduserer torskens vekst og forsinker kjønnsmodningen, som i neste generasjon reduserer beitepresset på lodde og eget avkom. Multidekadiske klimaendringer påvirker rekruttering og vekst hos sild og lodde, og sammen medfører disse interaksjonene også multidekadiske variasjoner i det årlige utbytte av torsk. Modellkjøring viser at det optimalt oppnåelige midlere utbytte over 10-års perioder oppnås ved å holde gytebestander på 200 000 til 300 000 tonn. Ved større torskebestander avtar den individuelle veksten, og kannibalismen øker så sterkt at langtidsutbyttet kan bli betydelig redusert. ICES`s råd til forvaltning av torskebestanden i Barentshavet har, per i dag, som mål å opprettholde gytebestander av torsk på 460 000 tonn

Life history and exploitation of the Norwegian spring spawning herring

Biology and fisheries of the Norwegian spring spawning herring and blue whiting in the Northeast Atlantic. Proceedings of the fourth Soviet-Norwegian Symposium. Bergen, 12 - 16 June 1989.This paper is a review of the history and exploitation of the Norwegian spring spawning herring stock. In a virgin state the biomass of this stock may have ranged from 15 to 20 million tonnes and it was the most important fish resource in the Northeast Atlantic. The adult stock utilized the rich plankton production along the Polar Front in the Norwegian Sea but spawned during winter on the Norwegian west coast. These spawners formed the basis for the largest fishery in Europe for centuries. The young and adolescent herring are distributed in Norwegian coastal waters and in the Barents Sea where they constitute the most important prey species or many stocks of predators, both of fish , birds and mammals. Due to technical advances the exploitation of the herring increased tremendously in the 1960's and the adult stock was fished out completely in 1970. Some small components of juvenile herring did however survive, and spawned on the traditional spawning grounds in 1973. After spawning the herring did not migrate to the traditional feeding area in the Norwegian Sea, but remained i n Norwegian coastal waters throughout the year. In later years the stock has recovered slowly, but the old traditional migration pattern of herring between the Polar Front area and the Norwegian coast has not yet been retained. It is concluded that the break down of the life cycles of the herring is the prime reason for the recent crisis which has developed in the Barents Sea stocks and fisheries

Cost optimization of an offshore wind farm integrated to an oil & gas platform

Master's thesis in Renewable energy (ENE500

Burial practices in early Christian Norway. An osteoarchaeological study into differences and similarities between four burial assemblages

The main topics of this thesis are the burial practices carried out at the time of early Christianity in Norway and how the burial practices relate to the burial regulations given in the provincial laws (Gulating, Frostating, Eidsivating, Borgarting). The study is based on the data collected from the examination of the skeletal material from four different graveyards and the data collected from the archaeological records from the different sites (St. Mary’s church in Bergen, Public Library site in Trondheim, Hamar cathedral and the St. Peter’s church in Tønsberg). Questions regarding sexual segregation and social stratification of the graveyards have been the main interest of this research, but other features which could have influenced the place of burial have also been touched upon: age, family relations, foreigners. It has been shown that the sexes were not treated equally on three of the four graveyards: there was no evidence suggesting that the sexes were ever segregated on the graveyard for the St. Mary’s church in Bergen. It has also become apparent that the separation of the sexes was adapted to the individual graveyard and did not necessarily follow the north-south division prescribed in the Eidsivating law and a pattern which has been shown on many graveyards in Sweden, Denmark, Iceland and Greenland. It has been argued that pathological conditions, especially degenerative changes to the joints and vertebrae, can be good indicators of social differences. Based on the distribution of these pathological conditions, strong evidence has been presented in favour of the graveyards having been socially stratified. It seems very likely that an individual’s social status decided a person’s placement on the graveyard at the Public Library site in Trondheim and for the St. Peter’s church in Tønsberg

Norwegian Newspapers in America: Connecting Norway and the New Land

Review of: "Norwegian Newspapers in America: Connecting Norway and the New Land," by Odd S. Lovoll