Priority management actions for alien freshwater fish species in Australia

In Australia, alien freshwater fish are continuing to steadily increase in number of species (reported in this paper to be 43), abundance, and distribution. In general however, their impacts are not well quantified in either environmental or economic terms and current management to reduce their impacts is limited and lacking direction. Although carp Cyprinus carpio have received some attention, very little is known about the impacts and even the distribution of most species. There is a lack of recognition of the problem, inconsistency in legislation, policy, and approaches across jurisdictions, and no nationally coordinated on?the?ground management actions. Where legislation and policy is available it is not always used to good effect. This paper provides a synthesis of existing knowledge of alien fishes in Australia, suggests a new management approach, and recommends priority management actions

Thalassorama: ITQs in the Australian South East Fishery

Environmental Economics and Policy,

Interscholastic Meet Program, 1928

Publication created for the annual Interscholastic Meet at the University of Montana.https://scholarworks.umt.edu/interscholastic_meet_publications/1076/thumbnail.jp

Age composition, growth, and reproduction of koi carp (Cyprinus carpio L.) in the lower Waikato, New Zealand

A total of 566 koi carp (Cyprinus carpio) from the lower Waikato region were aged from scales and opercular bones, and growth was modelled with the von Bertalanffy growth function. There was no difference in growth rate between male and female carp. Growth of koi carp between zero and 3 years of age was lower than that of common carp in Europe and Australia. However, after 5 years of age the growth of koi carp was higher than that of common carp in Europe, but still below that of carp in Australia. Males rarely lived in excess of 8 years, whereas females lived to 12 years. Mean total fecundity calculated from 44 running-ripe females was 299 000 oocytes (±195 600 SD) (range 29 800–771 000). Relative fecundity ranged from 19 300 to 216 000 oocytes kg–1 total body weight, with a mean of 97 200 (±35 000 SD) oocytes kg–1. Feral koi carp in the Waikato are capable of multiple spawnings within their lifetimes. Within a spawning season, Waikato populations of feral koi carp contained females that spawned once, and females that had the potential to have spawned repeatedly. Female gonadosomatic index (GSI) varied with season and was negatively related to water temperature

Determining and testing the optimal pure-tone frequency for use in acoustic conditioning of free-ranging common carp (Cyprinus carpio)

Pure-tone frequencies of 400, 700, and 1000 Hz were tested to determine which achieved the strongest response when used in conditioning experiments on captive common carp (Cyprinus carpio) for the purpose of determining the most effective frequency to use in conditioning experiments on free-ranging common carp. Captive common carp were shown to have the strongest response to the 400 Hz frequency after training that associated sound with food. Response was quantified as moving into a feeding arena when the sound was broadcast, and all frequencies achieved conditioning within five days. Secondly, the attenuation of the three frequencies were compared in a Waikato lake (Lake Kaituna) containing common carp. The ability to maintain signal strength over distance is necessary for frequencies used in the acoustic conditioning of free-ranging common carp due to the potentially large distances involved. Attenuation of the 400 Hz and 700 Hz pure tone frequencies were not significantly different but were both lower than that of the 1000 Hz frequency. The 400 Hz pure tone frequency was used in subsequent experiments on the acoustic conditioning of free-ranging common carp in Lake Kaituna because of superior performance in acoustic conditioning of captive common carp and low attenuation in a natural water body containing free-ranging common carp,. Thirdly, the 400 Hz pure tone was evaluated for its ability to be associated with food by free-ranging common carp. Capture rates at treatment sites where 400 Hz pure tone was broadcast compared to control sites where no sound was broadcast following a five-day training phase and 24 h of no sound or food, were 2.1 times greater during a three-day capture phase. This study demonstrates the trainability of common carp, a trait that can be used to improve control of wild common carp populations

Patterns and drivers of movement for a coastal benthopelagic fish, Pseudocaranx georgianus, on Australia's southeast coast.

Knowledge of connectivity and population structure is integral to the sustainable management of fished populations, yet such information is unavailable for many species over scales relevant to their exploitation. We examined broad-scale patterns and drivers of adult movement for a putatively mobile carangid (Pseudocaranx georgianus) on Australia's southeast coast using an angler tag-recapture dataset. More than 6300 individuals were tagged and released across 1007 km of coastline, with anglers recapturing 157 (2.48%) individuals during a 14-year period. Median distance moved was 5 km and a substantial proportion of individuals (19%) were recaptured at their release location. Recapture latitude was also strongly predicted by release latitude (r2 = 0.87). However, a broad range of movements were observed (0-508 km), with 6% of individuals moving further than 100 km. Most individuals recaptured in areas now designated as Marine Protected Areas (MPAs) were originally released in the same area (79.2%). Larger body size, longer periods at liberty, and releases during Spring all positively influenced distance moved. Results support restricted movement over an intermediate scale, punctuated by occasional large movements. Our findings suggest adult movement of P. georgianus in southeastern Australia primarily occurs over smaller distances than the current spatial scale of management

Experience in implementing harvest strategies in Australia's south-eastern fisheries

The Southern and Eastern Scalefish and Shark Fishery (SESSF) is a complex multi-species fishery, with 34 stock units under quota management, for which a harvest strategy framework was developed in 2005. The framework involves the application of a set of tier-based harvest control rules (HCR) designed to provide a precautionary approach to management. The harvest strategy framework has been applied from 2005 to 2007, resulting in substantial reductions in quotas across the fishery. The experience in implementing the framework, both positive and negative, is described, and general lessons are drawn. Key lessons include the importance of formally testing such strategies using management strategy evaluation, the impact of external management drivers on implementation of the approach, the need to define strategies for setting "bycatch quotas" in multi-species fisheries, and the need for flexibility and pragmatism in the early stages of implementing such an approach

A Model of the Market for ITQ in Australia's Multi-species South East Fishery

Around 100 commercial fish species are utilized by the trawl sector of the Australian South East Fishery, of which sixteen major species were brought into an ITQ management system in 1992. A revenue function approach is used to analyze catch, price and effort data for the period 1990-96, and to develop a set of individual vessel supply curves for quota species, and demand curves for quota. The latter, together with the quota supply constraints, are used to predict market prices of leased quota for each of the sixteen species. Predicted quota prices are compared with observed values, and the implications of various policy measures, including removing some species from the ITQ system, or removing some vessels from the fishery, are discussed.Key words: quota market, Australia, multi-species fisher

Efficiency gains and cost reductions from individual transferable quotas: A stochastic cost frontier for the Australian south east fishery

In this paper efficiency gains and associated cost reductions from increases in traded quota are estimated with a stochastic cost frontier for the Australian South East Trawl Fishery (SETF). Estimation of this frontier also provides key information on the relative importance of input costs in the SETF, returns to scale, variations in costs as a result of trade in quota and the economic performance of each fishing vessel, year to year. Final estimations indicate that increases in the volume of quota traded have resulted in considerable efficiency gains and cost reductions in the SETF, ranging from 1.8 to 3.5 cents per kilogram for surveyed vessels for every one per cent increase in the volume of quota traded, or 1 to 2.4 per cent of total variable costs, with considerable gains also accruing to crew and skipper in the form of larger share payments. Mean vessel efficiency is relatively high in the SETF, estimated at over 90 per cent, and increases further to 92 per cent over the sample period with increased trades in quota