Davies T.K.,Imperial College London |
Davies T.K.,MRAG Ltd |
Mees C.C.,MRAG Ltd |
Milner-Gulland E.J.,University of Oxford
PLoS ONE | Year: 2017
Spatial closures are widely used in marine conservation and fisheries management and it is important to understand their contribution to achieving management objectives. Many previous evaluations of closed area effects have used before-after comparisons, which, without controlling for a full range of factors, cannot ascribe changes in fleet behaviour to area closures per se. In this study we used a counterfactual approach to disentangle the effect of two closed areas on fishing location from other competing effects on the behaviour of the Indian Ocean tuna purse seine fishery. Our results revealed an inconsistent effect of the one of the closed areas between years, after taking into account the influence of environmental conditions on fleet behaviour. This suggests that the policy of closing the area per se was not the main driver for the fleet allocating its effort elsewhere. We also showed a marked difference in effect between the two closed areas resulting from their different locations in the fishery area. These findings highlight the need to account for other key fleet behavioural drivers when predicting or evaluating the contribution of area closures to achieving conservation and fishery management objectives. © 2017 Davies et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
News Article | May 16, 2017
This ends a five-year period without certification for this portion of the Alaska salmon fishery, which is one of the highest producing Alaska salmon fishing regions among 14 identified by the MSC. PWS lost its certification on October 30, 2012, when it failed to receive recertification to the MSC standard. The rest of the Alaska salmon fishery has been certified since Nov. 12, 2013, Jon Corsiglia, US spokesperson for the MSC, told Undercurrent News. Alaska salmon's MSC certification dates back to 2000, but it had lapsed following major processors' decision not to continue with the program when recertification came up in October of 2012. Today's PWS recertification, classified as a "scope extension", gives PWS an MSC certificate that is equivalent to the rest of the state's salmon fishery certification, which expires November 2018, Amanda Stern-Pilot MRAG Americas, the independent assessor of the PWS's MSC recertification, told Undercurrent. PWS's recertification is subject to successful completion of annual surveillance audits, MRAG said in a release. MRAG recommended certification late last month. This was subject to a 15-day period for stakeholders to file objections, which could potentially have halted the recertification process. This period ended May 11. "No objections were received, so it is officially recertified now," Corsiglia said. According to MRAG, the certification covers purse seine, drift gillnet and set gillnet for Prince William Sound sockeye, chinook, coho, pink and chum salmon. This ends a shut-out period from the MSC for PWS that arose over concerns of the region's use of hatchery fish. During the 2013 assessment third-party certification team's determination that the PWS unit should remain in assessment pending further analysis of an Alaska Department of Fish and Game multi-year study relating to the impacts of hatcheries on the populations of wild salmon and herring in the PWS, the MSC said. According to Corsiglia, these concerns over the use of hatchery fish have been since resolved in regards to the MSC certification. "As with all fisheries, the MSC process always seeks to take new information into account," Corsiglia said. "However, with today’s certification announcement, the concern from 2013 over wild/hatchery interaction has been resolved to the satisfaction of all engaged stakeholders." According to the MSC release, the PWS unit was assessed again via a scope extension to the valid Alaska Salmon certificate in 2016. "Based upon the findings quantified by the Alaska Hatchery Research Program, the certification assessment team has determined that the impacts of wild and hatchery salmon interactions are low and meet the sustainability requirements of the MSC Fisheries Standard," the MSC said. Following its lack of recertification with the rest of the Alaska salmon fishery in 2013, the PWS region ceased to be part of the MSC certification process temporarily in April of 2015, when the Alaska Salmon Processors Association -- the organization managing Alaska salmon's MSC certification process at that time -- withdrew the PWS portion from the fishery's certification program. The decision came as major Alaska salmon processors attempted to re-join the MSC. The lack of inclusion of PWS in the Alaska salmon fishery's 2013 recertification was so contentious that it caused Copper River Seafoods to drop out of the MSC certification process. The company, however, later changed its stance and became one of the few remaining companies in the MSC certification client group. Today's list of Alaska salmon companies authorized to carry the MSC stamp on their products includes Copper River Seafoods along with a long list of large and small Alaska salmon processors. These companies are part of the client group run by the Pacific Seafood Processors Association, whose president Glenn Reed welcomed this news. "The Alaska Salmon fishery management program and its participants are committed to sustainable use of the ocean’s natural resources, a key component of our business," Reed said. "We are proud to have the MSC process again recognize the sustainability of Prince William Sound and all Alaska salmon."
Arthur R.I.,MRAG Ltd. |
Friend R.M.,Independent Consultant
Global Environmental Change | Year: 2011
The inland capture fisheries of the Mekong represent critical sources of nutrition in rural diets in a region that faces endemic food and nutritional deficits. However within regional development debates that prioritize utilising the waters of the Mekong to generate electricity, capture fisheries are often presented as ultimately doomed, and therefore as an unfortunate, but necessary trade-off for hydropower. At the heart of these debates, lie contested definitions of development. The notion that fisheries could or should be traded-off for some other form of development exemplifies this tension. This paper draws on anthropological approaches to policy analysis based on discourse and narratives. We begin by placing the conventional wisdom regarding the place of fisheries in regional development under closer scrutiny. We then explore the potential for a counter narrative based around food and food sovereignty, in which fisheries and fishers are drivers, rather than costs of development. We argue that fisheries provide a range of livelihood and developmental values that cannot be replaced and that their management continues to hold potential for strengthening independence and self-reliance. In doing so, we build on empirical evidence from the Lao PDR, a country with a rich capture fishery but also endemic food crises, and also a national policy commitment to both poverty reduction and extensive large-scale hydropower development. As such, this paper attempts to reframe the debate on development in the Mekong. The paper has wider significance for considering how a broader focus on food and food producers can generate alternative development pathways. © 2010 Elsevier Ltd.
Hoshino E.,Imperial College London |
Hillary R.M.,CSIRO |
Pearce J.,MRAG Ltd.
Marine Resource Economics | Year: 2010
The fishery for Patagonian toothfish around the island of South Georgia in the Southern Ocean is a profitable operation targeting a high-value, slow-growing species. We substituted the complex Bayesian age-structured model currently used for assessments with a Schaefer production model, which performs equally well as an operating model for management strategy evaluation. Our analysis demonstrated that optimum long-term profitability using a discount rate of 2% would be achieved at a biomass of 59% of initial biomass, which is higher than the target biomass of 50% incorporated into the current management strategy, and at a reduction in effort of approximately 19%. A number of potential effort reduction strategies are investigated, several of which would achieve belter conservation objectives and higher future profits from the fishery than those predicted using the current management strategy. Copyright © 2010 MRE Foundation, Inc.
Moir Clark J.,MRAG Ltd |
Agnew D.J.,MRAG Ltd |
Agnew D.J.,Imperial College London
CCAMLR Science | Year: 2010
Observer data collected on longliners between 2003 and 2009 were analysed to look at the levels of depredation caused by killer whales (Orcinus orca) and sperm whales (Physeter macrocephalus) around South Georgia. Since 2003, cetaceans have been observed on 22% of 14 300 observed lines, with killer whales present on 3.8% and sperm whales on 17.7% of lines. Killer whales appear in pod sizes normally of 4 to 10 animals, and often appear to actively seek out fishing vessels and 'strip' the line of a large number of toothfish, usually depressing CPUE by about 50%. Sperm whales occur in smaller pod sizes, normally between 1 and 4 animals, and have a relatively lower impact on catches, depressing CPUE by up to 20%. Sperm whales have been more frequently encountered in recent years, occurring in larger pod sizes, whereas killer whale encounters and pod sizes have remained relatively constant. Most interactions from sperm whales occur during May at the start of the season with the sightings becoming fewer towards the end of the season in August. Killer whale interactions appear to be more consistent with no obvious pattern between months. Both species demonstrate an east to west migration throughout the season that is not related to the pattern of fishing effort. By comparing catch rates with and without the presence of cetaceans, accounting for other determinants of toothfish CPUE through a generalised linear model, it is estimated that the amounts of toothfish removed from longlines by cetaceans have varied between 1% and 8% of the declared catches over the period 2003-2009, with an average of 3.6%.
Taylor M.L.,University of Oxford |
Yesson C.,UK Institute of Zoology |
Agnew D.J.,Imperial College London |
Mitchell R.E.,MRAG Ltd |
Rogers A.D.,University of Oxford
Journal of Biogeography | Year: 2013
Aim: For many deep-sea fisheries, there is an urgent management requirement for information on the presence of vulnerable marine ecosystems (VMEs). Gathering deep-sea data using conventional techniques can be expensive and time-consuming. One way to provide a relatively rapid assessment of VME presence is to use data from fisheries by-catch and historical scientific observations. Our aim was to predict suitable habitat for octocorals around South Georgia and to estimate the extent to which octocoral habitat is currently protected by fisheries management measures. In addition, we attempted to determine the types of terrain in which octocorals and fishing activities occur. Location: South Georgia, sub-Antarctic. Methods: A terrain map of South Georgia was created using Benthic Terrain Modeler (BTM). Georeferenced octocoral data were combined with environmental layers to create an octocoral habitat suitability map using ecological niche factor analysis (ENFA). Results: Most octocoral by-catch samples originated from narrow crest (an area representing shelf break and moraines) and steep (continental) slope terrains. Calcite saturation state and apparent oxygen utilization (AOU) were the most influential environmental parameters in determining highly suitable octocoral habitat. The ENFA model highlighted shelf-break areas to be highly suitable habitat for octocorals and that 38% of this habitat around South Georgia lies within areas currently protected by fisheries management; a further 20% is below the 2000-m fishing depth, meaning effectively that 58% of predicted highly suitable octocoral habitat is currently protected. Although these results indicate protection levels for octocoral habitat well above international standards/targets, the fishery remains active within a relatively concentrated shelf area at 700-2000 m, potentially having a large impact on the 42% of highly suitable octocoral habitat predicted to lie at these depths. Main conclusions: This research demonstrates the potential for using fisheries by-catch data to create habitat suitability maps that can inform fisheries management and future research. © 2013 John Wiley & Sons Ltd.
Davies T.K.,Imperial College London |
Mees C.C.,MRAG Ltd |
Milner-Gulland E.J.,Imperial College London
Marine Policy | Year: 2015
An important task of natural resource management is deciding amongst alternative policy options, including how interventions will affect the dynamics of resource exploitation. Yet predicting the behaviour of natural resource users in complex, changeable systems presents a significant challenge for managers. Scenario planning, which involves thinking creatively about how a socio-ecological system might develop under a set of possible futures, was used to explore uncertainties in the future of the Indian Ocean tuna purse seine fishery. This exercise stimulated thinking on how key social, economic and environmental conditions that influence fleet behaviour may change in the future, and how these changes might affect the dynamics of fishing effort. Three storylines were explored: an increase in marine protection, growing consumer preference for sustainable seafood, and depletion of tuna stocks. Comparing across several possible future scenarios, a number of critical aspects of fleet behaviour were identified that should be important considerations for fishery managers, but which are currently poorly understood. These included a switch in fishing practices, reallocation of effort in space, investment in new vessels and exit from the fishery. Recommendations for future management interventions in the Indian Ocean were offered, along with suggestions for research needed to reduce management uncertainty. © 2015 The Authors.
Roberts J.,Imperial College London |
Xavier J.C.,University of Coimbra |
Xavier J.C.,Natural Environment Research Council |
Agnew D.J.,Imperial College London |
Agnew D.J.,MRAG Ltd
Journal of Fish Biology | Year: 2011
The diets of Antarctic toothfish Dissostichus mawsoni and Patagonian toothfish Dissostichus eleginoides were examined around the South Sandwich Islands in the Southern Ocean, one of few regions with overlapping populations of the two species. Despite large differences in the proportion of stomachs containing prey (76·2% of D. mawsoni compared to 7·2% of D. eleginoides), diet composition was broadly similar (Schoener overlap index of 74·4% based on prey mass) with finfishes (particularly macrourids and muraenolepidids) and cephalopods (mainly Kondakovia longimana) comprising >90% of the prey mass of both species. Predation rates of the main fish prey, as mean counts per stomach sampled, were spatially correlated with their relative abundance around the islands derived from fishery by-catch data, suggesting a general lack of prey selectivity. This study supports the view that bathyal Dissostichus are opportunistic carnivores and finds that D. mawsoni and D. eleginoides occupy a similar trophic niche and are likely to compete for prey in regions where both are distributed. The large increase in rate of prey occurrence and size of prey in D. mawsoni stomachs relative to D. eleginoides suggests, however, species differences in feeding behaviour, which may reflect the increased metabolic demands of a cold-water adapted physiology. © 2011 The Authors. Journal of Fish Biology © 2011 The Fisheries Society of the British Isles.
Arthur R.I.,MRAG Ltd
Society and Natural Resources | Year: 2012
Overfishing is a messy and contested term often associated with problems of numbers of people, particularly poor people, and something inherent in the nature of fisheries themselves. It has an intuitive appeal, implying something wrong and something that needs to be done. Although often grounded in science, when overfishing appears in policy debates in the Mekong its definition is rarely stated and the lack of evidence is readily acknowledged. Overfishing is one of a number of potential threats to the Mekong fisheries and there is a risk in overplaying the significance of overfishing, such that policy debates are limited and courses of action narrowed. In the face of current debates about fisheries in the context of water resource management, this article places the storyline of overfishing under closer scrutiny and seeks a more rigorous and nuanced assessment of threats and responses, less constrained by the confines of debates on "overfishing." © 2012 Taylor & Francis Group, LLC.
Davies T.K.,Imperial College London |
Mees C.C.,MRAG Ltd. |
Milner-Gulland E.J.,Imperial College London
Marine Policy | Year: 2014
The use of drifting fish aggregating devices (FADs) has become the dominant practice in tropical tuna purse seine fishing. However, just as FADs can increase fishing efficiency, their use has been associated with several negative ecosystem impacts, and moves are being made to manage the use of FADs. In the evaluation of potential management options it is important to consider how fishers will respond to the introduction of control measures, which first requires an understanding of fishery and fleet dynamics. This paper addresses this need by characterising the past and present use of FADs in the Indian Ocean tropical tuna purse seine fishery. The paper describes historical trends in fishing practices, summarises spatiotemporal patterns in the use of FADs and establishes and attributes variation in FAD fishing strategies within the fleet. It also provides an overview of current FAD management policies in the Indian Ocean and examines the observed effects of existing measures on the behaviour of the purse seine fleet. Using this comprehensive understanding, the potential impact on the purse seine fleet of a number of plausible FAD management options are discussed and inferences are drawn for the future sustainability of tropical tuna purse seine fishing in the Indian Ocean. © 2014 The Authors.