The Economics of Allocation in Tuna Regional Fisheries Management Organizations (RFMOS)

The paper reviews existing allocation mechanisms in the five tuna regional fisheries management organizatins and shows that although they have adopted different approaches all have failed to prevent overcapacity and, or some stocks, overexploitation. As an alternative, it is proposed that each tuna regional fishing management organization establish total allowable catches by species and area, and then allocate non-transferable and permanent country shares (as a proportion of the total harvest) to member countries. Each country would be free to use or sell its annual allocation of fish that would be determined by the permanent country shares, but the sales could only be to fellow member countries. A two-tier allocation to countries of permanenet shares of a total allowable catch, and then annual harvest allocations to vessels of member countries, offers the promise of mitigating, and possibly overcoming, the twin problems of overcapacity and overexploitation in the highly migratory and high seas tuna fisheries.tuna, property rights, allocation

Central nervous system tumours in Icelandic children; diagnoses, treatment results and late effects

Neðst á síðunni er hægt að nálgast greinina í heild sinni með því að smella á hlekkinn View/OpenObjective: Tumours in the central nervous system are the second most common malignant diseases in children. With improved treatment, the number of survivors is increasing. Therefore, better knowledge of the long-term effects of the disease and the therapy is needed. The aim of the current study was to find the incidence of central nervous system tumours in Iceland, evaluate the treatment results and study the long-term effects on the individuals. Material and methods: Data on diagnosis and treatment as well as demographic data were gathered from hospital records from the Reykjavik City Hospital and The University Hospital and operating lists at the Department of Neurosurgery were reviewed. On survivors, physical examination was carried out, blood tests and urine-analysis were done and hearing was tested. Social adaptation, school performance, memory, concentration and general well being were studied by a questionnaire. Results: In the years 1970-1995, 57 children, aged 16 and younger, were diagnosed in Iceland with central nervous system tumours, 30 girls and 27 boys. Two children with brain metastases were excluded. Of the 55 individuals, 38 are alive today, 19 girls and 19 boys. Seventeen children had astrocytoma, grade 1 or 2 and seven had astrocytoma of grade 3 or 4. Seven children had medulloblastoma, other tumours were less common. Four patients with benign tumours in the spine were excluded from the study; three are living abroad and three refused participation. Therefore, 28 patients were included in the further study, 15 males and 13 females. The mean age at diagnoses was 7 years and 8 months (7:8) (median 6:7 years, span 0:0-15:11), the mean age at study was 21:4 years (median 20:2 years, span 7:6-39:9) and the mean time from diagnosis until study was 12:8 years (median 11:5 years, span 2:5-26:3). The mean standard deviation score for height (SDS) was -0.63 at the time of study, five of the patients had SDS below two. Five individuals need hormone replacement therapy and one patient has scoliosis. Three patients have disabilities; two of those are incapable of activities of daily life. Three patients have hearing impairment; one of them is also blind. Of five patients who had seizures when diagnosed, two still have convulsions. Of 28 patients, twelve (43%) had learning difficulties in school and ten (36%) needed remedial teaching. Conclusions: The incidence of central nervous tumours in Icelandic children is comparable to what has been reported in other countries. The results of the treatment are similar to what has been found in the other Nordic countries which maybe better than in other countries. The most prominent long-term effects among the survivors are endocrine dysfunctions and specific learning disabilities. Other, severe long-term complications are rare but have considerable effect on the individuals. We emphazise that organised, long-term follow-up is essential for these individuals, paying special attention to learning difficulties and endocrine dysfunction.Inngangur: Æxli í miðtaugakerfi er annar algengasti illkynja sjúkdómurinn í börnum, næst á eftir hvítblæði. Árangur meðferðar hefur farið stöðugt batnandi og því eykst mikilvægi þess að greina möguleg langtímaáhrif og síðkomna fylgikvilla meðferðar. Tilgangur rannsóknarinnar var að finna heildarfjölda sjúklinga á Íslandi, greiningu þeirra og árangur meðferðar og kanna síðkomna fylgikvilla og langtímaáhrif meðferðar á eftirlifandi einstaklinga. Aðferðir: Sjúklingar voru fundnir með leit í sjúkraskrám á Sjúkrahúsi Reykjavíkur og Landspítalanum auk þess sem farið var yfir aðgerðarbækur á SHR. Upplýsingar um sjúkdóminn, greiningu og meðferð var safnað. Allir þátttakendur í rannsókninni komu í viðtal og skoðun, heyrnarmælingu, blóð- og þvagrannsóknir. Spurningalisti varðandi félagslega aðlögun, skólagöngu, minni, einbeitingu og líðan var einnig lagður fyrir þátttakendur. Niðurstöður: Á árunum 1970-1995 greindust 57 börn á Íslandi yngri en 16 ára með æxli í miðtaugakerfi, 30 stelpur og 27 strákar. Tveir sjúklingar með meinvörp í heila voru útilokaðir frá frekari uppvinnslu. Nú eru 38 þessara einstaklinga á lífi, 19 konur og 19 karlar. Sautján sjúklingar höfðu astrocytoma af gráðu 1 eða 2 en sjö sjúklingar astrocytoma af gráðu 3 eða 4. Sjö sjúklingar höfðu greinst með medulloblastoma, aðrar tegundir voru sjaldgæfari. Fjórir sjúklingar með góðkynja æxli í mænu voru útilokaðir frá rannsókn. Þrír búa erlendis og þrír neituðu þátttöku. Því tóku 28 einstaklingar þátt í rannsókninni, 15 karlmenn og 13 konur. Aldur við greiningu var að meðaltali sjö ár og átta mánuðir (7:8) (miðgildi 6:7 ár, bil 0:0-15:11), meðalaldur við rannsókn var 21:4 ár (miðgildi 20:2 ár, bil 7:6-39:9) og meðaltími frá greiningu að rannsókn var 12:8 ár (miðgildi 11:5 ár, bil 2:5-26:3). Hæð þátttakenda við rannsókn var að meðaltali -0,63 staðalfráviksskor (standard deviation score; SDS), fimm þátttakendur eru með -2 eða minna í staðalfráviksskori. Fimm einstaklingar fá hormónameðferð vegna vanstarfsemi innkirtla í kjölfar meðferðar. Einn einstaklingur hefur hryggskekkju sem rekja má til meðferðar. Þrír einstaklingar hafa verulega skerta hreyfifærni sem rekja má til sjúkdómsins og/eða meðferðar og þar af eru tveir ófærir um athafnir daglegs lífs. Þrír einstaklingar eru heyrnarskertir, þar af er einn einnig blindur. Af fimm sjúklingum sem höfðu krampa sem einkenni um sjúkdóminn fá tveir enn krampa. Af 28 sjúklingum áttu 12 (43%) við sérstaka námsörðugleika að stríða í grunnskóla og tíu (36%) fengu stuðningskennslu. Umræður: Tíðni heila- og mænuæxla virðist sú sama hér og þekkist annars staðar. Árangur meðferðar virðist svipaður og á hinum Norðurlöndunum sem er oft betri en í öðrum löndum. Þau langtímaáhrif sem eru mest áberandi hjá einstaklingum sem lifað hafa æxli í miðtaugakerfi í æsku eru vanstarfsemi innkirtla og sértækir námsörðugleikar. Aðrir alvarlegir fylgikvillar eru ekki algengir en skerða þó lífsgæði einstaklingsins. Nauðsynlegt er að bjóða upp á skipulagt og markvisst eftirlit með þessum sjúklingum að meðferð lokinni með áherslu á að greina námsörðugleika og starfstruflanir í innkirtlum

Incentive-based approaches to sustainable fisheries (now replaced by EEN0508)

Using examples from more than a dozen fisheries, we highlight the failures of ‘command control’ management and show that approaches that empower fishers with the incentives and the mandate to be co-custodians of the marine environment can promote sustainability. Evidence is provided that where harvesters share well-defined management responsibilities over fish, and experience both the pain of overexploitation and the gains from conservation, they are much more likely to protect fish stocks and habitat. The key insight is that to maintain marine ecosystems for present and future generations, fishing incentives must be compatible with long-term goals of sustainability.incentives, sustainability, rights, fisheries management

Incentive-based approaches to sustainable fisheries

The failures of traditional target-species management have led many to propose an ecosystem approach to fisheries to promote sustainability. The ecosystem approach is necessary, especially to account for fishery-ecosystem interactions, but by itself is not sufficient to address two important factors contributing to unsustainable fisheries — inappropriate incentives bearing on fishers, and the ineffective governance that frequently exists in commercial, developed fisheries managed primarily by total harvest limits and input-controls. We contend that much greater emphasis must be placed on fisher motivation when managing fisheries. Using evidence from more than a dozen ‘natural experiments’ in commercial fisheries, we argue that incentive-based approaches that better specify community, individual harvest, or territorial rights and also price ecosystem services — coupled with public research, monitoring and effective oversight — promote sustainable fisheries.incentives, sustainability, rights, fisheries management

How to share underground reservoirs

Many resources, such as oil, gas, or water, are extracted from porous soils and their exploration is often shared among different companies or nations. We show that the effective shares can be obtained by invading the porous medium simultaneously with various fluids. Partitioning a volume in two parts requires one division surface while the simultaneous boundary between three parts consists of lines. We identify and characterize these lines, showing that they form a fractal set consisting of a single thread spanning the medium and a surrounding cloud of loops. While the spanning thread has fractal dimension ${1.55\pm0.03}$, the set of all lines has dimension ${1.69\pm0.02}$. The size distribution of the loops follows a power law and the evolution of the set of lines exhibits a tricritical point described by a crossover with a negative dimension at criticality

Demographic Diversity and Sustainable Fisheries

Fish species are diverse. For example, some exhibit early maturation while others delay maturation, some adopt semelparous reproductive strategies while others are iteroparous, and some are long-lived and others short-lived. The diversity is likely to have profound effects on fish population dynamics, which in turn has implications for fisheries management. In this study, a simple density-dependent stage-structured population model was used to investigate the effect of life history traits on sustainable yield, population resilience, and the coefficient of variation (CV) of the adult abundance. The study showed that semelparous fish can produce very high sustainable yields, near or above 50% of the carrying capacity, whereas long-lived iteroparous fish can produce very low sustainable yields, which are often much less than 10% of the carrying capacity. The difference is not because of different levels of sustainable fishing mortality rate, but because of difference in the sensitivity of the equilibrium abundance to fishing mortality. On the other hand, the resilience of fish stocks increases from delayed maturation to early maturation strategies but remains almost unchanged from semelparous to long-lived iteroparous. The CV of the adult abundance increases with increased fishing mortality, not because more individuals are recruited into the adult stage (as previous speculated), but because the mean abundance is more sensitive to fishing mortality than its standard deviation. The magnitudes of these effects vary depending on the life history strategies of the fish species involved. It is evident that any past high yield of long-lived iteroparous fish is a transient yield level, and future commercial fisheries should focus more on fish that are short-lived (including semelparous species) with high compensatory capacity

Charting the course for a Blue Economy in Peru: A Research Agenda

Ocean- and coastal-based economic activities are increasingly recognised as key drivers for supporting global economies. This move towards the “blue economy” is becoming globally widespread, with the recognition that if ocean-based activities are to be sustainable, they will need to move beyond solely extractive and exploitative endeavours, aligning more closely with marine conservation and effective marine spatial planning. In this paper we define the “blue economy” as a “platform for strategic, integrated and participatory coastal and ocean development and protection that incorporates a low carbon economy, the ecosystem approach and human well-being through advancing regional industries, services and activities”. In Peru, while the seas contribute greatly to the national economy, the full potential of the blue economy has yet to be realised. This paper presents the findings of an early career scientist workshop in Lima, Peru, in March 2016. The workshop “Advancing Green Growth in Peru” brought together researchers to identify challenges and opportunities for green growth across three Peruvian economic sectors—tourism, transport and the blue economy with this paper exploring in detail the priorities generated from the “blue economy” stream. These priorities include themes such as marine spatial planning, detailed evaluations of existing maritime industries (e.g. guano collection and fisheries), development of an effective MPA network, support for sustainable coastal tourism, and better inclusion of social science disciplines in understanding societal and political support for a Peruvian blue economy. In addition, the paper discusses the research requirements associated with these priorities. While not a comprehensive list, these priorities provide a starting point for future dialogue on a co-ordinated scientific platform supporting the blue growth agenda in Peru, and in other regions working towards a successful “blue economy”