Understanding and mitigating seabird bycatch in the South African pelagic longline fishery

Seabirds are considered one of the most threatened groups of birds in the world. They face additional mortality both on their breeding islands from introduced predators and at sea by fishing fleets, as fisheries bycatch, as well as other human impacts. Seabird bycatch has negatively affected many seabird populations worldwide, with trawl, gillnet and longline fisheries considered the most destructive to seabird populations. Seabird bycatch from trawl and gillnet fisheries has been significantly reduced in recent years, but large numbers of seabirds are still killed annually by longline fisheries. Of the two types of longline fisheries (demersal and pelagic), pelagic longlining is considered the most harmful to seabirds as lines remain closer to the surface for longer periods than demersal longlining, and it is harder to weight lines to ensure rapid sinking beyond the depth they are accessible to birds. Seabirds are killed when they swallow baited hooks and consequently drown. Despite the large number of studies investigating seabird bycatch from pelagic longline fisheries, there remain gaps in our understanding of seabird bycatch from pelagic longline fisheries. This thesis addresses some of these knowledge gaps and makes recommendations as to how seabird bycatch from pelagic longliners can be reduced at both a local and global scale. Chapters 2 and 3 investigate the factors affecting seabird bycatch from pelagic longliners off South Africa, provide a summary of seabird bycatch from the fishery for the period 2006–2013 and quantify the structure of seabird assemblages associated with pelagic longline vessels off South Africa. This was achieved by analysing seabird bycatch data collected by fisheries observers as well as data from sea trials onboard pelagic longliners. Seabird bycatch by pelagic longliners off South Africa over the 8-year study period has been significantly reduced from the 8-year period (1998–2005), mainly driven by a significant reduction in seabird bycatch rates from foreign-flagged vessels, which are responsible for c. 80% of fishing effort off South Africa. Seabird bycatch rates from South African vessels still remain high, four times higher than the interim national target of < 0.05 birds per 1000 hooks. The species composition of seabird bycatch off South Africa is best explained by an understanding of the structure of the seabird assemblage associated with longline vessels. For most species, bycatch and attendance ratios were similar, but for some species such as shy-type and black-browed albatrosses there were large mismatches, likely caused by differences in foraging behaviour and foraging dominance hierarchies. In Chapters 4 and 5 the foraging ecology of the most commonly recorded bycatch species off South Africa, the white-chinned petrel (Procellaria aequinoctialis), is investigated. An understanding of the foraging ecology of commonly recorded bycatch species enhances our understanding of seabird bycatch and helps to improve the design of current and future mitigation measures. The year-round movements of white-chinned petrels from Marion Island were investigated with Global Location Sensors (GLS loggers) and GPS loggers. Adult white-chinned petrels undertake only limited east-west movements of, with all birds remaining between southern Africa and Antarctica. These results strengthen the theory that there is limited spatial overlap year-round between white-chinned petrel populations from South Georgia, the southern Indian Ocean islands and New Zealand sub-Antarctic islands, suggesting that these populations can be managed as separate stocks. The diving behaviour of white-chinned and grey petrels (P. cinerea), another common bycatch species in Southern Ocean longline fleets, were examined with the use of temperature-depth recorders (TDRs), deployed on birds from Marion Island and Gough Island. My study was the first to analyse TDR dive data from any Procellaria petrel, and recorded them reaching maximum dive depths of 16 and 22 m, respectively. Current best practise suggests that baited hooks be protected to a depth of 5 m by bird-scaring lines, but my results suggest this depth should be increased to at least 10 m. Although line weighting is a proven mitigation measure to reduce seabird bycatch from pelagic longliners, fishers have concerns that it will compromise fish catches, crew safety and operational efficiency. In Chapter 6 I analyse line weighting data from trials onboard three pelagic longline vessels, to address the concerns of fishermen. My results show that sliding leads can be incorporated into pelagic longline fisheries without compromising fish catch, crew safety or operational efficiency. I thus recommend that sliding leads be used on pelagic longline vessels fishing off South Africa. By incorporating studies investigating the factors affecting seabird bycatch, seabird foraging ecology and the efficacy of seabird bycatch mitigation measures, my thesis has broadened our understating of seabird bycatch from pelagic longliners and makes meaningful recommendations to further reduce bycatch, both locally and globally. Although seabird bycatch rates have declined off South Africa, through the use of a number different mitigation measures, they still remain higher than the South African national target and thus more work is needed to achieve this target. To reduce seabird bycatch from pelagic longliners to acceptable levels, studies from the world's various longline fleets needs to be considered and improved upon, with seabird conservationists and fishermen working together to achieve this goal

The welfare effects of regulatory change on the Western Canadian grain handling and transportation system

Abstract Lisitza, Lyndon D. M.Sc. University of Saskatchewan, Saskatoon, May 2012. The Welfare Effects of Regulatory Change on the Western Canadian Grain Handling and Transportation System. Supervisor: Dr. Murray E. Fulton In 1996, the federal government took a significant step toward redefining the regulatory framework for grain transportation on the Prairies with the passing of the Canadian Transportation Act (CTA). The CTA contained two significant aspects that were to have a major impact on the GHTS. The first aspect concerned rail line abandonment. Under the CTA, protections afforded to the discontinuance of grain dependent branchlines were removed. Instead, railways were simply required to generate a three-year plan to indicate whether they intended to continue operating a branchline or whether they intended to sell, lease or abandon it. The second aspect was the introduction of regulated maximum freight rates, which removed the federal government from direct financial intervention in the GHTS. This policy was designed to replace the remnants of the long-standing Crow rate for Canadian railways. In order to determine if regulatory change has led to an overall improvement in GHTS welfare, and to determine if farmers have benefitted from regulatory change, this thesis examined the regulatory changes that have occurred since the passing of the Canada Transportation Act (Act). To provide some context for this analysis, this thesis presents a historical overview of the legislation and regulations leading up to the passing of the Act and provided a historical and current description of the GHTS market structure. Following the regulatory and industry overview, this thesis develops a theoretical framework capable of determining whether regulatory change has lead to an overall improvement in GHTS welfare and, if so, which industry participants have benefitted from this change. To help contextualize many of the concepts used in the theoretical framework, this thesis examines theories on the origin of regulation and looked specifically at two forms of thought: public interest theory and capture theory. As well, this thesis examines several ‘rate of return’ regulatory options available to the regulator, and provides an illustration of the ‘rate of return’ regulation of the WGTA in order to provide a regulatory baseline against which the 1996 CTA regulatory changes can be assessed. The intent of this thesis is to quantify the changes in consumer and producer surplus associated with regulatory change. Specifically, this examines the welfare changes in grain and non-grain markets that can be attributed to the shift from the WGTA to revenue cap regulation, increased railway capacity, a reduction in railway marginal cost and the removal of grain dependent branch lines (GDBLs). When considering the welfare effects solely attributed to the regulatory shift, the results indicate that the move from the WGTA to the revenue cap decreases the consumer surplus of farmers. Farmers experience an overall reduction in consumer surplus, largely due to the fact that the price farmers’ pay for grain transportation has risen and because the level of output they receive is less than that received under the WGTA. As a result of the regulatory shift, shippers in the non-grain market see an overall gain in consumer surplus. This increase is principally due to a shift in capacity allocation from the grain to the non-grain market as the railways respond to the higher marginal revenues they are able to earn in the non-grain market as opposed to the revenue cap regulated grain market. As such, shippers in the non-grain market are made better off. Although the railways experience a loss in producer surplus due to the regulatory shift, this loss is more than offset by the increase in producer surplus that the railways earn through a reduction in marginal costs. As such, the railways see an overall gain in producer surplus. As well, the federal government also experiences a gain in overall surplus. These gains are the result of the elimination of the subsidy that was paid to the railways under the WGTA as well as the removal of the additional dead weight loss that is incurred by society resulting from raising the taxes required to pay the subsidy. As such, the government (i.e., taxpayers) are better off as a result of the regulatory change

Infrared spectrum and stability of a π-type hydrogen-bonded complex between the OH and C2H2 reactants

A hydrogen-bonded complex between the hydroxyl radical and acetylene has been stabilized in the reactant channel well leading to the addition reaction and characterized by infrared action spectroscopy in the OH overtone region. Analysis of the rotational band structure associated with the a-type transition observed at 6885.53(1) cm−1 (origin) reveals a T-shaped structure with a 3.327(5) Å separation between the centers of mass of the monomer constituents. The OH (v = 1) product states populated following vibrational predissociation show that dissociation proceeds by two mechanisms: intramolecular vibrational to rotational energy transfer and intermolecular vibrational energy transfer. The highest observed OH product state establishes an upper limit of 956 cm−1 for the stability of the π-type hydrogen-bonded complex. The experimental results are in good accord with the intermolecular distance and well depth at the T-shaped minimum energy configuration obtained from complementary ab initio calculations, which were carried out at the restricted coupled cluster singles, doubles, noniterative triples level of theory with extrapolation to the complete basis set limit

FISHING STRATEGY OF THE INDONESIAN TUNA LONGLINERS IN INDIAN OCEAN

Information on fishing strategy is essential to manage the Indonesian tuna fishery. Therefore, it is important to attempt to characterise the fishing strategies of the fishery

The Japanese Bluefin Tuna Longline Fishery in the Northeast Atlantic: Report of an Irish Observer

This paper describes an observer trip on a Japanese freezer longliner in the international waters of the North East Atlantic in the autumn of 1997. The observation period was 71 days during which 7 species were recorded as catch and bycatch from 57 sets. Although bluefin tuna was the target species, with 18,894kg gilled and gutted weight (GWT) caught, the most frequently retained species was blue shark, Prionace glauca, followed by bluefin tuna. Three shortfin mako shark, Isurus oxyrinchus, one swordfish, Xiphias gladius and one anglerfish, Lophius spp., were also recorded. The most frequently discarded species were lancetfish Alepisaurus ferox, and deal fish Trachipterus arcticus. Bluefin tuna ranged from 139cm to 275cm in fork length (FL) and from 64kg to 347kg in round weight (RWT) with clear modes of 190cm and 136kg. Recent ageing results from the North East Atlantic infer ages of 4 to 17 years old. CPUE was lower than Norwegian sponsored trials in the North East Atlantic in 1998 and similar to those computed by the Japanese longline observer programme in 2000, 2001 and 2002. There was no evidence of trend in bluefin CPUE over the course of the observation period. The modelled length weight relationship predicted higher values than established length weight relationships for bluefin tuna in the East Atlantic: ICCAT modelled RWT for East Atlantic bluefin was 87% of the observed round weight and 90% of the predicted RWT value for Koshin Maru #8 tuna. Over the observation period the condition of bluefin tuna was found to decline and examination of stomachs showed that most were empty or contained low numbers of prey items. Declining condition factors and apparent scarcity of prey are discussed in the context of CPUE. Prey scarcity reflected in declining condition may increase the effectiveness of baited hooks causing abundance estimates derived from CPUE series to over-estimate the population of bluefin tuna in the North East Atlantic. Investigation of condition indices has the potential to estimate stock ratios in longline catches in the North Atlantic. All observed blue shark catch were female with lengths ranging from 140cm to 250cm.Funder: Marine Institut

Catch Rates with Variable Strength Circle Hooks in the Hawaii-Based Tuna Longline Fishery

The Hawaii-based deep-set longline fleet targets bigeye tuna [Thunnus obesus (Lowe, 1839)] and infrequently takes false killer whales [FKW , Pseudorca crassidens (Owen, 1846)] as bycatch. From 2004 to 2008 with 20%–26% observer coverage, nine mortalities of and serious injuries to FKW were documented in the deep-set fishery in the Hawaii EE Z, yielding a mean take estimate of 7.3 animals yr−1. Weak hook technology can utilize the size disparity between target and other species to promote the release of larger non-target species. Four vessels tested the catch efficacy and size selectivity of 15/0 “strong” circle hooks (4.5 mm wire diameter) that straighten at 138 kg of pull in comparison with 15/0 “weak” (4.0 mm) that straighten at 93 kg of pull. Vessels alternated hook types throughout the longline gear and maintained a 1:1 ratio of strong and weak hooks. Observers monitored a total of 127 sets of 302,738 hooks, and randomization tests were applied to test for significant differences in catch for 22 species. There were no significant catch differences for bigeye tuna; however, there may be limitations to these inferences because trials were not conducted during spring when larger bigeye tuna are available to the fishery. There were no significant differences in mean length of 15 species. Observers collected 76 straightened hooks, of which six were control and 70 were weak hooks. There was one observation of a FKW released from a stronger circle hook. Overall, there was no statistical reduction in catch rates of bycatch species

Small cetacean captures and CPUE estimates in artisanal fisheries operating from a port in northern Peru, 2005-2007. Scientific Committee document SC/60/SM19, International Whaling Commission, June 2008, Santiago, Chile

This work provides the first direct, at-sea monitoring of small cetacean interactions with Peruvian artisanal drift gillnet and longline vessels. A total of 253 small cetaceans were observed captured during 66 fishing trips (480 sets) monitored from March 2005-July 2007 in the port of Salaverry, northern Peru. Interactions consisted of 231 animals caught in gillnets, 1 in a longline and 21 direct takes by harpooning for use as bait. The most commonly captured species were long-beaked common dolphins Delphinus capensis, dusky dolphins Lagenorhynchus obscurus, common bottlenose dolphins Tursiops truncates (offshore stock) and Burmeister’s porpoises Phocoena spinipinnis. Overall bycatch CPUE (catch per unit effort) was estimated to be 0.677 animals/set and 0.007 animals/set for gillnet and longline vessels, respectively. Based upon total fishing effort for the port, we estimated the average of small cetacean bycatch at 2,623 animals/year (CI 2,061-3,185) for 2002-2007. This work indicates that, in at least one Peruvian port, bycatch and harpooning of small cetaceans persist at high levels and on a regular basis, particularly in driftnet vessels. The formerly unknown practice of at-sea discarding of carcasses stands in sharp contrast with current, high small cetacean discard rates (49%) found in this study. That, combined with high prices/lack of availability of traditional bait fish suggest that small cetacean bycatch and harpooning could now potentially be reduced through the implementation of bycatch mitigation measures and greater accessibility to preferred bait