Economic repercussions of fisheries-induced evolution

Fish stocks experiencing high fishing mortality show a tendency to mature earlier and at a smaller size, which may have a genetic component and therefore long-lasting economic and biological effects. To date, the economic effects of such ecoevolutionary dynamics have not been empirically investigated. Using 70 y of data, we develop a bioeconomic model for Northeast Arctic cod to compare the economic yield in a model in which life-history traits can vary only through phenotypic plasticity with a model in which, in addition, genetic changes can occur. We find that evolutionary changes toward faster growth and earlier maturation occur consistently even if a stock is optimally managed. However, if a stock is managed optimally, the evolutionary changes actually increase economic yield because faster growth and earlier maturation raise the stock's productivity. The optimal fishing mortality is almost identical for the evolutionary and nonevolutionary model and substantially lower than what it has been historically. Therefore, the costs of ignoring evolution under optimal management regimes are negligible. However, if fishing mortality is as high as it has been historically, evolutionary changes may result in economic losses, but only if the fishery is selecting for medium-sized individuals. Because evolution facilitates growth, the fish are younger and still immature when they are susceptible to getting caught, which outweighs the increase in productivity due to fish spawning at an earlier age

Where could catch shares prevent stock collapse?

In a widely received study (Science 321: 1678–1681) Costello and his colleagues found that catch shares give better stock persistence and higher catch for fishermen. The conclusions made by Costello et al were further being supported by Grafton and McIlgrom (Marine Policy 33: 714– 719) where they suggested a framework in order to determine the costs and benefits of separate ITQ management in seven Australian commonwealth fisheries, and what the alternatives should be if the net benefits do not justify ITQs. This raises the question why we do not see catch shares being used more often. We explore at a global scale which countries would have the potential for – and indeed do fulfil the conditions necessary to implement such a management strategy

Roles of density-dependent growth and life history evolution in accounting for fisheries-induced trait changes

The relative roles of density dependence and life history evolution in contributing to rapid fisheries-induced trait changes remain debated. In the 1930s, northeast Arctic cod (Gadus morhua), currently the world’s largest cod stock, experienced a shift from a traditional spawning-ground fishery to an industrial trawl fishery with elevated exploitation in the stock’s feeding grounds. Since then, age and length at maturation have declined dramatically, a trend paralleled in other exploited stocks worldwide. These trends can be explained by demographic truncation of the population’s age structure, phenotypic plasticity in maturation arising through density-dependent growth, fisheries-induced evolution favoring faster-growing or earlier-maturing fish, or a combination of these processes. Here, we use a multitrait eco-evolutionary model to assess the capacity of these processes to reproduce 74 y of historical data on age and length at maturation in northeast Arctic cod, while mimicking the stock’s historical harvesting regime. Our results show that model predictions critically depend on the assumed density dependence of growth: when this is weak, life history evolution might be necessary to prevent stock collapse, whereas when a stronger density dependence estimated from recent data is used, the role of evolution in explaining fisheries-induced trait changes is diminished. Our integrative analysis of density-dependent growth, multitrait evolution, and stock-specific time series data underscores the importance of jointly considering evolutionary and ecological processes, enabling a more comprehensive perspective on empirically observed stock dynamics than previous studies could provide

A bio-economic analysis of harvest control rules for the Northeast Arctic cod fishery

Harvest control rules (HCRs) have been implemented for many fisheries worldwide. However, in most instances, those HCRs are not based on the explicit feedbacks between stock properties and economic considerations. This paper develops a bio-economic model that evaluates the HCR adopted in 2004 by the Joint Norwegian-Russian Fishery Commission to manage the world's largest cod stock, Northeast Arctic cod (NEA). The model considered here is biologically and economically detailed, and is the firt to compare the performance of the stock's current HCR with that of alternative HCRs derived with optimality criteria. In particular, HCRs are optimized for economic objectives including fleet profit, economic welfare, and total yield and the emerging properties are analyzed. The performance of these optimal HCRs was compared with the currently used HCR. This paper show that the current HCR does in fact comes very close to maximizing profits. Furthermore, the results reveal that the HCR that maximizes profits is the most precautionary one among the considered HCRs. Finally, the HCR that maximizes yield leads to un-precautionary low levels of biomass. In these ways, the implementation of the HCR for NEA cod can be viewed as a success story that may provide valuable lessons for other fishries

Climatic effects filtered through the food web affect the dynamics of Arcto-Norwegian cod

The world's largest cod stock, the Arcto-Norwegian cod (a.k.a. North-East Arctic cod), is heavily influenced by temperature in two ways: First, cod recruitment tends to be high when Barents Sea temperature in the spawning year is high. Secondly, there is a more indirect effect of climate via herring and capelin: Warm conditions increase the chance of high recruitment of Norwegian Spring-spawning herring; 1-2 year old herring eat 0-year old capelin; and cod cannibalism increases when the biomass of 1-4 year old capelin is low. While these relationships have been shown separately and for the later years, we develop and parameterize models for the effects of herring (via capelin) and temperature on cod recruitment at age 3, using data from 1973 until present. Using data on cod, herring and temperature back to 1921 to verify the model,we find a significant relationship between predictions and data back to the 1950s, but before this, the predicted time-series pattern is not observed in the data

Alpha managers - an advantage or disadvantage for the organization

The role of the manager is crucial to the organization. Managers set goals, develop strategies and define tasks of workers, create environment for the development of people and give meaning to their activities. Professional skills are of vital importance to manager’s success. These very skills are the distinguishing characteristics of alpha managers. The aim of the following paper is to present some of the most established ideas in the field of leadership styles, to compare them with the concept of alpha managers and draw some conclusions important to management

Finansiell risikostyring i Cermaq ASA

Studentarbeid i økonomi og ledelse (bachelorgrad) - Universitetet i Nordland, 2012Temaet for denne oppgaven er risikostyring av finansielle risikofaktorer. Vi har valgt å knytte temaet opp mot Cermaq, og oppgaven tar sikte på å finne ut til hvilken grad Cermaq tar hensyn til markedsrisiko og kredittrisiko. For å finne ut av dette har vi valgt å undersøke hvordan Cermaq sikrer disse risikofaktorene, og motivasjonen for at de gjør som de gjør. Siden Cermaq er involvert i både fôrproduksjon og fiskeoppdrett, har vi undersøkt hvordan dette påvikrer selskapets risikoeksponering. Videre har vi belyst likhetstrekk mellom Cermaqs risikostyring og COSOs rammeverk for helhetlig risikostyring. I undersøkelsen har vi gjennomført et dybdeintervju med to av Cermaqs nøkkelansatte på disse områdene, samtidig som vi har hentet informasjon fra selskapets årsrapporter. Dataene blir så presentert og analysert, før vi bruker det som grunnlag for oppgavens konklusjon. Det vi avdekket var at Cermaq i stor grad benytter seg av de fordelene naturlig sikring medfører, og at dette i mange tilfeller gir utslag i en håndterlig risikoeksponering for selskapet. I de situasjoner hvor naturlig sikring blir vurdert som ikke tilstrekkelig, bruker de derivater. De bruker derivater regelmessig når det kommer til håndtering av prisrisiko knyttet til laks. I forhold til valutarisiko utnytter de sine naturlige sikringer i størst mulig grad, men i ekstraordinære tilfeller benyttes derivater. Eksponeringen knyttet til renterisiko blir vurdert som håndterlig og derfor ikke sikret. Kredittrisikoen blir håndtert gjennom å ha en kredittkomiè som overvåker kredittgivningen. De bruker også kredittforsikringer. Vi avdekket også risikoreduserende aspekter ved å være involvert i fôrproduksjon og oppdrettsnæringen. Dette knytter seg blant annet til netting benefits, altså at selskapssammensetningen bidrar til en naturlig sikring mot transaksjonsrisiko. I tillegg virker Ewos stabiliserende på konsernet som helhet, gjennom sine forutsigbare driftsresultat

A bio-economic analysis of harvest control rules for the Northeast Arctic cod fishery

-Harvest control rules (HCRs) have been implemented for many fisheries worldwide. However, in most instances, those HCRs are not based on the explicit feedbacks between stock properties and economic considerations. This paper develops a bio-economic model that evaluates the HCR adopted in 2004 by the Joint Norwegian–Russian Fishery Commission to manage the world's largest cod stock, Northeast Arctic cod (NEA). The model considered here is biologically and economically detailed, and is the first to compare the performance of the stock's current HCR with that of alternative HCRs derived with optimality criteria. In particular, HCRs are optimized for economic objectives including fleet profits, economic welfare, and total yield and the emerging properties are analyzed. The performance of these optimal HCRs was compared with the currently used HCR. This paper show that the current HCR does in fact comes very close to maximizing profits. Furthermore, the results reveal that the HCR that maximizes profits is the most precautionary one among the considered HCRs. Finally, the HCR that maximizes yield leads to un-precautionary low levels of biomass. In these ways, the implementation of the HCR for NEA cod can be viewed as a success story that may provide valuable lessons for other fisheries