Can vertical separation of species in trawls be utilized to reduce bycatch in shrimp fisheries?

Several shrimp trawl fisheries use a Nordmöre sorting grid to avoid bycatch of fish. However, small fish can pass through the grid. Therefore, the retention of juvenile fish often remains an issue during shrimp trawling. We investigated the vertical distribution of deepwater shrimp (Pandalus borealis) and dominant bycatch species at the point where the Nordmöre grid section is installed. This was achieved using a separator frame which split the net vertically into three compartments of equal entry size. Our results showed that shrimp predominately follow the lower part of the trawl belly, whereas species such as redfish (Sebastes spp.), cod (Gadus morhua), polar cod (Boreogadus saida) and American plaice (Hippoglossoides platessoides) preferred the mid-section in the aft of the trawl. Haddock (Melanogrammus aeglefinus) primarily entered through the upper section of the trawl belly. Using these results, we predict that a vertical separation device installed forward of a 19 mm Nordmöre grid combined with a 35 mm codend would result in a significant reduction in bycatch with only minor loss of shrimp.

Centre and Periphery of Nano-A Norwegian Context.

This work describes the nano field in Norway as currently emerging in the dynamics between two forms of nano research activities described along a centre-periphery axis. 1) There are strategic research initiatives committed to redeem the envisioned potential of the field by means of social and material reorganisation of existing research activities. This activity is seen as central as it is one of our premises that the standard circulating nano vision implies such a work of reorganisation. The fact that nano is often taken as a paradigmatic example of the shift from Mode-1 to Mode-2 research, supports this assumption. 2) In parallel to this activity, a wide variety of research projects pursuing nano strategies are being funded. We regard such research activity as peripheral in so far as the activity is not marked by being committed to the circulating nano vision, as may often be the case. In the process of reorganising, this article argues, the research activity at the periphery provides a crucial arena for discussing and validating what is to be achieved through the work of reorganisation that takes place at the centre. Our analysis is informed by two Norwegian cases. We examine a major nano research initiative at a Norwegian university as a centre and a research project utilising nanoparticles in fish vaccines as a periphery.

Mapping Uncertainties in the Upstream: The Case of PLGA Nanoparticles in Salmon Vaccines.

The diversity of nanotechnologies and of the governance challenges that their applications raise calls for exploration and learning across different cases. We present an Upstream Oversight Assessment (UOA) of expected benefits and potential harms of nanoparticles made of a synthetic polymer (PLGA) to improve vaccines for farmed salmon. Suggested by Jennifer Kuzma and colleagues, an UOA may help identify and prioritise research needs, and it may support evaluations of the adequacy of relevant existing regulatory frameworks. In this work, the UOA approach is modified and supported with elements from the uncertainty analysis framework developed by Warren Walker and colleagues. Empirically, we draw on relevant available published literature and insights generated in an ongoing nanoparticle salmon vaccine project, in which one of the authors participates. Nanotechnologies have not previously been encountered in the regulatory context of fish vaccines, which in part raises unique challenges due to prospective large scale vaccine use in semi-open aquatic systems. Strengthened through cooperation between ELSA and technology researchers we found the UOA useful for an early mapping of benefits and concerns, and for identifying areas in need of further research prior to a nanoparticle based salmon vaccine is developed and taken into use. We consider our approach to represent one among several complementing initiatives that seek to contribute to early stage evaluations of possible negative side effects, broadly conceived, in order to facilitate a more robust nanotechnology development.