Impacts of rising sea temperatures on krill increase risks for predators in the Scotia Sea

Climate change is a threat to marine ecosystems and the services they provide, and reducing fishing pressure is one option for mitigating the overall consequences for marine biota. We used a minimally realistic ecosystem model to examine how projected effects of ocean warming on the growth of Antarctic krill, Euphausia superba, might affect populations of krill and dependent predators (whales, penguins, seals, and fish) in the Scotia Sea. We also investigated the potential to mitigate depletion risk for predators by curtailing krill fishing at different points in the 21st century. The projected effects of ocean warming on krill biomass were strongest in the northern Scotia Sea, with a ≥40% decline in the mass of individual krill. Projections also suggest a 25% chance that krill biomass will fall below an established depletion threshold (75% of its unimpacted level), with consequent risks for some predator populations, especially penguins. Average penguin abundance declined by up to 30% of its unimpacted level, with up to a 50% chance of falling below the depletion threshold. Simulated krill fishing at currently permitted harvest rates further increased risks for depletion, and stopping fishing offset the increased risks associated with ocean warming in our model to some extent. These results varied by location and species group. Risk reductions at smaller spatial scales also differed from those at the regional level, which suggests that some predator populations may be more vulnerable than others to future changes in krill biomass. However, impacts on predators did not always map directly to those for krill. Our findings indicate the importance of identifying vulnerable marine populations and targeting protection measures at appropriate spatial scales, and the potential for spatially-structured management to avoid aggravating risks associated with rising ocean temperatures. This may help balance tradeoffs among marine ecosystem services in an uncertain future

Assessment of the Falkland Islands population of Argentine hake Merluccius hubbsi.

Spanish vessels fish for the Argentine hake, Merluccius hubbsi both in Falkland Islands Conservation Zones and in high seas waters along the shelf edge to the north of the islands. Data are collected by the Falkland Islands Fisheries Department, Instituto Español de Oceanografía and Asociación Nacional de Armadores de Buques Congeladores de Pesca de Merluza. Data from these three sources were combined, with the aim of producing assessments of M. hubbsi. There was no relationship between abundance indices for Falkland Islands waters and high seas areas, suggesting little interaction between the populations in the two areas. Virtual population analysis suggested that the spawning stock biomass in Falklands waters declined from approximately 60,000 t in 1987 to about 15,000 t in the early 1990s but has since made a partial recovery to approximately 20,000 t. However, low recruitment levels are, apparently, impeding the recovery of the population. The abundance trend contrasts with a continued decline suggested by assessments of the population in Argentine waters, implying some independence of the adult populations in the two areas. Nonetheless, it is likely that recruitment to the population is affected by processes not explained by the available data

Overview of the Spanish fisheries in the Patagonian Shelf

The fishing grounds of the Patagonian Shelf support some of the most important fisheries in the world. The great abundance of marine resources among parallels 35º and 54º South, is associated with the Subtropical Convergence formed by the Brazil and Falkland/Malvinas currents. The mixing of the flow of La Plata River and the western branch of the Falkland/Malvinas Current generates areas of high plankton production on the shelf. Hakes (Merluccius hubbsi and Merluccius australis) and cephalopods (Illex argentinus and Loligo gahi) have been found the main commercial species, with important amounts of accompanying species in the catches such as Patagonian toothfish (Dissostichus eleginoides), Kingclip (Genypterus blacodes), Hoki (Macruronus magellanicus), Red cod (Salilota australis), Southern blue whiting (Micromesistius australis), etc. These fisheries are currently among the most important to the Spanish bottom trawler freezing fleet that has around 40 vessels fishing in this area, besides another 20 that operate in joint ventures sailing Falkland flag. It is estimated that this fleet generates approximately 2,000 direct offshore jobs, and more than 10,000 indirect onshore jobs. This paper presents results from the EC Study Project 99/016 “Data collection for stock assessment of two hakes (Merluccius hubbsi and M. australis) in international and Falkland waters of the SW Atlantic”. Historical fishery and biological data series available from the Instituto Español de Oceanografía (IEO) and the Falkland Islands Fishery Department (FIFD) were used during the project to describe fishing patterns and spatio-temporal changes in the abundance and distribution of target and accompanying species, as well as to give an overview of these important fisheries

Promoting higher added value to a finfish species rejected to sea

This project aimed to the development of the research and the technology necessary to promote higher added value to fishing activity. This is to be achieved by obtaining profit from a finfish species (“Rockcod”, Patagonotothen spp.) not known to consumers and currently discarded by the EU fishing fleet operating in the South West Atlantic, in order to supply the EU seafood industry with a good quality raw material for human food manufacturing. Use of this species, caught as a by-catch in the existing fisheries targeting hakes and cephalopods, should also increase the profitability of the fleet, contribute to maintaining employment and help to counterbalance the negative effects of fishing activity and discards in the ecosystem. The main scientific-technological objectives and expected achievements were the following: - Description of the fisheries - Improved knowledge of the biology of the species - Biomass assessment - Estimation of catches and discards - Analysis of the spatial and temporal distribution of the resource. Fishery forecasting and testing - Sensorial, Microbiological, Nutritional and Biochemical Evaluation of Rock cod - Development of the technical modifications on board commercial vessels - Development of new processed products from frozen Rock codEuropean Commission Cooperative Research (CRAFT

Implementation and the Governance Problem: A Pressure Participant Perspective

This article has two aims: to qualify the UK government's ‘problem' of governance in a comparison with Scotland and Wales, and to use implementation studies (the ancestors of the new governance literature) to explore policy developments since devolution in Britain. It presents a puzzling finding from extensive interview research: that while we may expect UK government policy to suffer a bigger ‘implementation gap' based on distinctive governance problems (such as greater service delivery fragmentation and the unintended consequences of top-down policy styles), pressure participants in Scotland and Wales are more likely to report implementation failures. Using a ‘top-down' framework, it explores three main explanations for this finding: that the size of the implementation gap in England is exaggerated by a focus on particular governance problems; that pressure participant dissatisfaction follows unrealistic expectations in the devolved territories; and that the UK government undermines devolved policy implementation, by retaining control of key policy instruments and setting the agenda on measures of implementation success

Searches for Neutrinos from LHAASO ultra-high-energy {\gamma}-ray sources using the IceCube Neutrino Observatory

Galactic PeVatrons are Galactic sources theorized to accelerate cosmic rays up to PeV in energy. The accelerated cosmic rays are expected to interact hadronically with nearby ambient gas or the interstellar medium, resulting in {\gamma}-rays and neutrinos. Recently, the Large High Altitude Air Shower Observatory (LHAASO) identified 12 {\gamma}-ray sources with emissions above 100 TeV, making them candidates for PeV cosmic-ray accelerators (PeVatrons). While at these high energies the Klein-Nishina effect suppresses exponentially leptonic emission from Galactic sources, evidence for neutrino emission would unequivocally confirm hadronic acceleration. Here, we present the results of a search for neutrinos from these {\gamma}-ray sources and stacking searches testing for excess neutrino emission from all 12 sources as well as their subcatalogs of supernova remnants and pulsar wind nebulae with 11 years of track events from the IceCube Neutrino Observatory. No significant emissions were found. Based on the resulting limits, we place constraints on the fraction of {\gamma}-ray flux originating from the hadronic processes in the Crab Nebula and LHAASOJ2226+6057

All-flavor constraints on nonstandard neutrino interactions and generalized matter potential with three years of IceCube DeepCore data

We report constraints on nonstandard neutrino interactions (NSI) from the observation of atmospheric neutrinos with IceCube, limiting all individual coupling strengths from a single dataset. Furthermore, IceCube is the first experiment to constrain flavor-violating and nonuniversal couplings simultaneously. Hypothetical NSI are generically expected to arise due to the exchange of a new heavy mediator particle. Neutrinos propagating in matter scatter off fermions in the forward direction with negligible momentum transfer. Hence the study of the matter effect on neutrinos propagating in the Earth is sensitive to NSI independently of the energy scale of new physics. We present constraints on NSI obtained with an all-flavor event sample of atmospheric neutrinos based on three years of IceCube DeepCore data. The analysis uses neutrinos arriving from all directions, with reconstructed energies between 5.6 GeV and 100 GeV. We report constraints on the individual NSI coupling strengths considered singly, allowing for complex phases in the case of flavor-violating couplings. This demonstrates that IceCube is sensitive to the full NSI flavor structure at a level competitive with limits from the global analysis of all other experiments. In addition, we investigate a generalized matter potential, whose overall scale and flavor structure are also constrained

Search for Quantum Gravity Using Astrophysical Neutrino Flavour with IceCube

Along their long propagation from production to detection, neutrino states undergo quantum interference which converts their types, or flavours. High-energy astrophysical neutrinos, first observed by the IceCube Neutrino Observatory, are known to propagate unperturbed over a billion light years in vacuum. These neutrinos act as the largest quantum interferometer and are sensitive to the smallest effects in vacuum due to new physics. Quantum gravity (QG) aims to describe gravity in a quantum mechanical framework, unifying matter, forces and space-time. QG effects are expected to appear at the ultra-high-energy scale known as the Planck energy, $E_{P}\equiv 1.22\times 10^{19}$~giga-electronvolts (GeV). Such a high-energy universe would have existed only right after the Big Bang and it is inaccessible by human technologies. On the other hand, it is speculated that the effects of QG may exist in our low-energy vacuum, but are suppressed by the Planck energy as $E_{P}^{-1}$ ($\sim 10^{-19}$~GeV$^{-1}$), $E_{P}^{-2}$ ($\sim 10^{-38}$~GeV$^{-2}$), or its higher powers. The coupling of particles to these effects is too small to measure in kinematic observables, but the phase shift of neutrino waves could cause observable flavour conversions. Here, we report the first result of neutrino interferometry~\cite{Aartsen:2017ibm} using astrophysical neutrino flavours to search for new space-time structure. We did not find any evidence of anomalous flavour conversion in IceCube astrophysical neutrino flavour data. We place the most stringent limits of any known technologies, down to $10^{-42}$~GeV$^{-2}$, on the dimension-six operators that parameterize the space-time defects for preferred astrophysical production scenarios. For the first time, we unambiguously reach the signal region of quantum-gravity-motivated physics.Comment: The main text is 7 pages with 3 figures and 1 table. The Appendix includes 5 pages with 3 figure

Searches for Neutrinos from Gamma-Ray Bursts using the IceCube Neutrino Observatory

Gamma-ray bursts (GRBs) are considered as promising sources of ultra-high-energy cosmic rays (UHECRs) due to their large power output. Observing a neutrino flux from GRBs would offer evidence that GRBs are hadronic accelerators of UHECRs. Previous IceCube analyses, which primarily focused on neutrinos arriving in temporal coincidence with the prompt gamma rays, found no significant neutrino excess. The four analyses presented in this paper extend the region of interest to 14 days before and after the prompt phase, including generic extended time windows and targeted precursor searches. GRBs were selected between May 2011 and October 2018 to align with the data set of candidate muon-neutrino events observed by IceCube. No evidence of correlation between neutrino events and GRBs was found in these analyses. Limits are set to constrain the contribution of the cosmic GRB population to the diffuse astrophysical neutrino flux observed by IceCube. Prompt neutrino emission from GRBs is limited to $\lesssim$1% of the observed diffuse neutrino flux, and emission on timescales up to $10^4$ s is constrained to 24% of the total diffuse flux