How fishers' count: engaging with fishers' knowledge in fisheries science and management

Engaging with fishers’ knowledge (FK) is increasingly valued in fisheries management (a) for FK’s utility for science and management, and (b) to improve the legitimacy of fisheries governance. Referring to both perspectives, this thesis examines: the nature and types of FK; FK’s relationship to scientific knowledge; and ‘extractive’ and ‘participative’ approaches taken to engage with FK. Chapters 3 and 4 compare fishers’ reports of catch rates with official landings data and underwater visual census (UVC). In Seychelles, contemporary reported catch rates and landings were consistent; but FK, landings and UVC perceived different trends over time. Over five western-Indian-Ocean countries, reported catch rates had no detectable relationship with UVC-measured fish biomass, despite a six-fold range in biomass. Such disparities between fishers’ and scientists’ perceptions provide opportunities to broaden the information base for monitoring; but challenge the legitimacy of science-based management in the eyes of resource users. Chapters 5 and 6 examine extractive approaches to engage FK. An interview-based stock assessment in Seychelles indicated that stocks were overexploited in contradiction to the qualitative perceptions of interviewed fishers. The extractive approach did not take account of fishers’ mental models which diverged from scientific assumptions about fish population dynamics and catch rates. In the North Sea, a postal questionnaire collected FK on stock trends, but had limited potential to influence scientific advice and satisfy fishers’ expectations, due to its limited scope T. Daw. How Fishers Count Page 3 and the lack of frameworks to utilise FK. Both cases illustrate the limitations of extractive methods, and the importance of engaging with more complex types of FK. Disagreements with science seem likelier, and more difficult to resolve for abstract types of FK. Extractive approaches can engage large numbers of fishers, but are less reliable and fail to improve governance. Participatory approaches, including collaborative research have greater promise for improving fisheries science and management.EThOS - Electronic Theses Online ServiceNatural Environment Research Council : Economic and Social Research CouncilGBUnited Kingdo

Surface core excitons in III-V semiconductors

Recent experiments have shown that the cation core excitons on the (110) surface of many III-V semiconductors have very large binding energies.(^1) They are sometimes reported to be bound by as much as ≳0.8 eV, tightly bound compared to bulk binding energies of ≾0.1 eV. To explore this phenomenon, we have calculated the binding energies and oscillator strengths of core excitons on the (110) surface of GaAs, GaSb, GaP, and InP

Ecosystem Approach to Small Scale Tropical Marine Fisheries

This is a 4-page brochure about a WorldFish led project. Throughout the world, poor fisheries management contributes to resource degradation, poverty, and food insecurity. This European Union project on an Ecosystem Approach to Small-scale Tropical Marine Fisheries is led by WorldFish and implemented in collaboration with national partners in Asia (Southeastern)-Indonesia; the Asia (Southeastern)-Philippines; the Solomon Islands and Tanzania. The overall objective is to use an ecosystem approach to fisheries management (EAFM) to improve governance of small-scale fisheries (SSF). The EAFM puts sustainability and equitability at the forefront of fisheries governance which enhances their contribution to poverty reduction.Specific objectives are to: 1. Assess existing institutional arrangements and identify opportunities for an EAFM to improve integrated SSF management; 2. Develop EAFM strategies and actions suitable for developing country contexts; 3. Strengthen the capacity of local fishery stakeholders and government agencies to collaborate and work within an EAFM. The project is taking a participatory and gender sensitive approach, both core philosophies of WorldFish. Representatives of all relevant stakeholder groups are involved in this action research project

Lag effects in the impacts of mass coral bleaching on coral reef fish, fisheries, and ecosystems

Recent episodes of coral bleaching have led to wide-scale loss of reef corals and raised concerns over the effectiveness of existing conservation and management efforts. The 1998 bleaching event was most severe in the western Indian Ocean, where coral declined by up to 90% in some locations. Using fisheries-independent data, we assessed the long-term impacts of this event on fishery target species in the Seychelles, the overall size structure of the fish assemblage, and the effectiveness of two marine protected areas (MPAs) in protecting fish communities. The biomass of fished species above the size retained in fish traps changed little between 1994 and 2005, indicating no current effect on fishery yields. Biomass remained higher in MPAs, indicating they were effective in protecting fish stocks. Nevertheless, the size structure of the fish communities, as described with size-spectra analysis, changed in both fished areas and MPAs, with a decline in smaller fish (<30 cm) and an increase in larger fish (>45 cm). We believe this represents a time-lag response to a reduction in reef structural complexity brought about because fishes are being lost through natural mortality and fishing, and are not being replaced by juveniles. This effect is expected to be greater in terms of fisheries productivity and, because congruent patterns are observed for herbivores, suggests that MPAs do not offer coral reefs long-term resilience to bleaching events. Corallivores and planktivores declined strikingly in abundance, particularly in MPAs, and this decline was associated with a similar pattern of decline in their preferred corals. We suggest that climate-mediated disturbances, such as coral bleaching, be at the fore of conservation planning for coral reefs.\u

Superfluidity and dimerization in a multilayered system of fermionic polar molecules

We consider a layered system of fermionic molecules with permanent dipole moments aligned by an external field. The dipole interactions between fermions in adjacent layers are attractive and induce inter-layer pairing. Due to competition for pairing among adjacent layers, the mean-field ground state of the layered system is a dimerized superfluid, with pairing only between every-other layer. We construct an effective Ising-XY lattice model that describes the interplay between dimerization and superfluid phase fluctuations. In addition to the dimerized superfluid ground state, and high temperature normal state, at intermediate temperature, we find an unusual dimerized "pseudogap" state with only short-range phase coherence. We propose light scattering experiments to detect dimerization.Comment: 4 pages main text + 3 pages supplemental Appendices, 4 figure