Development and implementation of allocation arrangements for recreational and commercial fishing sectors in Western Australia

This paper examines why Western Australia's Integrated Fisheries Management (IFM) policy was adopted, its development, achievements, lessons learned and future directions. Adopted in 2004, IFM aims to achieve and maintain fish resource sustainability through optimal catch share arrangements between competing users. It involves setting an allowable harvest level for each resource, using an independent allocation committee process to allocate explicit catch shares for commercial, recreational and customary sectors, and monitoring sectoral catch. IFM provides guidance for managing each sector within its catch share, providing access to that share, and developing reallocation mechanisms to transfer sectoral catch shares. The three most important multi‐sector resources, western rock lobster, Panulirus cygnus George, metropolitan Roe's abalone, Haliotis roei Grey, and west coast demersal scalefish, have undergone the allocation process. The first two are operational while the third is almost complete. Allocation outcomes demonstrate the need to account for each sector's catch, with credible scientific data to underpin decision‐making, independent transparent allocation processes, robust sectoral representation, workable reallocation mechanisms and management arrangements to ensure that all sectors can access their allocated share. IFM generates fair decisions for optimal resource use to reduce intersectoral conflict and provide better community outcomes, with wide applicability across other jurisdictions.     

Confidence intervals on catch estimates from a recreational fishing survey: a comparison of bootstrap methods

Bootstrap methods are often used for confidence intervals on recreational fish catch estimates, because they are relatively robust and straightforward to implement. Such data are typically highly skewed and zero‐inflated, presenting difficulties for many estimation methods. However, bootstrap performance in many situations is not well understood. Inaccurate confidence intervals can cause management errors, and biased intervals can promote errors in one direction. Although the analyses originate from recreational fisheries data, the conclusions are generally applicable to similarly distributed data from other sources. Using simulation, non‐parametric bootstrap confidence intervals (bootstrap normal, bootstrap percentile, hybrid, bootstrap‐t, BC, and BCa) on catch rate and total catch estimates from a recreational fishing survey were compared. The intervals' coverage (proportion of times the ‘true’ mean fell within the confidence intervals) and relative bias were also compared. The bootstrap‐t, using a resample size of slightly less than n/2, provided confidence intervals with the most correct coverage for both parameters. Intervals were biased, usually substantially, for all other methods, with the commonly used bootstrap percentile among the more biased methods.     

Evaluation of observer‐ and industry‐based catch data in a recreational charter fishery

There is international recognition for greater inclusion of recreational fisheries catch data in species, fisheries and ecosystem assessments. Recreational charter fisheries provide important social services and contribute to total species catches. This study compares and validates industry logbook catch and effort data (1,357 trips) against observer data (154 trips) across six ports in a recreational charter fishery in eastern Australia. The mean numbers of clients and fishing effort (hours) per trip varied inconsistently between data sources and among ports. Logbooks did not adequately report released catches, and the mean number of species retained per trip was consistently underestimated in logbooks compared to observer data. For both data sources, catch rates of total individuals and key species displayed similar trends across different units of effort; catch per hour, client, client/hour and trip. The mean catch rates of total individuals and most key species, except those retained for bait, were similar across data sources, as were estimates of total fleet harvests. The length compositions of retained catches of some key species displayed truncation of larger organisms in the observer data whereas other species did not. Despite the shortcomings of the logbook data, future fishery and species monitoring strategies could include industry and observer data sources.     

Communication between scientists,fishery managers and recreational fishers: lessons learned from a comparative analysis of international case studies

The management of recreational fisheries benefits from good collaboration between scientists, managers and recreational fishers. However, the level of collaboration largely depends on the levels of effective communication among the different stakeholders. This paper presents the views of scientists, managers and fishers concerning the quality of communication in eleven case studies of recreational fisheries. Case studies were synthesised and common reasons why communication did not always flow as intended were identified. The prevalent barriers to good communication, and therefore collaboration included a lack of rigorous scientific information transfer from scientists to fishers and managers, a fear from fishers that management actions will limit fishing opportunities, pre‐existing antagonism between commercial and recreational fisheries, and fishers' suspicion of science. Overcoming these issues is paramount to improve collaboration and participatory processes that help lead to robust, well‐accepted management actions.     

The relationship between stock and catch and the effect of bait on catch as determined for a UK recreational catch and release fishery

Abstract Twelve anglers fishing in a UK navigation canal for a total of 42 h caught 567 fish, mainly gudgeon, Gobio gobio (L.) ( n =306) and roach, Rutilus rutilus (L.) ( n =253) at an average catch rate of 13.4 fish angler-h⁻¹ or 128.5 g angler-h⁻¹. The species and size of fish caught were compared with the numbers determined by depletion estimates at six sections of canal using micromesh seine netting. Fifty four percent of fish caught in the net were < 60 mm FL. Gudgeon (60–99 mm) were over-represented in the anglers' catches whilst roach (60–99 mm) were under-represented. The size distribution of roach and gudgeon caught by anglers using two types of bait (small maggots and chironomid larvae) was examined and smaller fish were found to be caught using the latter.     

中西太平洋鲣渔场时空分布研究

中西太平洋海域是全球鲣(Katsuwonus pelamis)作业的主要渔场,该海域鲣渔场的时空分布规律,尤其是高产海域,是渔情预报研究的基础和前提。根据太平洋共同体秘书处提供的1995-2014年中西太平洋鲣围网捕捞生产统计数据,对各年各月的鲣产量和捕捞努力量渔获量(CPUE)进行统计分析,通过产量重心分析和聚类分析,找出渔场重心变化规律,同时选取高产的22个渔区(分辨率5°×5°),研究时间和空间因素对CPUE的影响。研究结果表明,中西太平洋鲣历年产量逐步上升,CPUE波动较大,而各月产量和CPUE差异较大,高产月份主要集中在上半年;历年产量重心分布不均,经度方向上分布差异较大,聚类分析可分为4类;各月产量重心变化呈现顺时针变化规律,从南到北,自西向东,再从北向南移动,聚类分析可分为3类;渔获量主要分布于5°S～5°N、120°～175°E,因此对该海域CPUE进行统计,以年份、月份和渔区为影响因素,分析发现,极端气候年份与其它年份的CPUE有明显不同,月份间的变化与产量月间重心变化类似,上、下半年有着明显不同;不同空间下,经度间差异大于纬度间差异,135°～145°E为经度CPUE差异的分界线,而南北纬间的差异不明显。上述鲣的时空分布变化主要与ENSO现象引起的西太平洋暖池的变化有着密切关系,同时太平洋岛国的相关入渔政策也对其产生一定的影响。     

Methodological, conceptual and sampling practices in surveying recreational fisheries in the Nordic countries – experiences of a valuation survey

The planning and initial phases of a joint Nordic project for the valuation of recreational fisheries is described. The economic value of recreational fisheries was taken to include non-market value as well as the traditional market value. The design of the survey was similar for each country so as to facilitate future comparison. However, initially there were difficulties in defining categories of recreational fishermen in the different countries. Other background information also had to be adapted to national circumstances. National population registers were used as the sampling frames. The effect of this on the responses from a valuation survey is discussed. Accessibility to population register data varies by country and so do possibilities for random sampling. Legal constraints were faced when implementing a centralised mailing system.     

Cetacean occurrence,habitat preferences and potential for cetacean–fishery interactions in Iberian Atlantic waters: results from cooperative research involving local stakeholders

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Illustrating the critical role of human dimensions research for understanding and managing recreational fisheries within a social‐ecological system framework

Effective management of recreational fishing requires understanding fishers and their actions. These actions constitute critical links between social and ecological systems that result in outcomes that feedback and influence recreational fishers' actions and the management of these actions. Although much research exists on recreational fishers and their actions, this research is often disconnected from management issues. One way to help to overcome this disconnect is to illustrate how past research on the social component of recreational fishing fits within an emerging coupled social‐ecological system (SES) framework. Herein, a conceptual SES is first developed with specific attention to recreational fisheries. This SES is then used to illustrate the importance of considering human dimensions research for articulating, studying and ultimately managing key outcomes of recreational fisheries (e.g. fish population conservation, fisher well‐being) using the example of harvest regulations and a brief review of past interdisciplinary research on recreational fishing. The article ends by identifying key research needs including understanding: how factors such as management rules affect the diversity of actions by recreational fishers; how governance and management approaches adapt to changing social and resource conditions; and how recreational fishers learn and share information.     

Spatial distribution of fishing effort in relation to seafloor habitats in the Kattegat,a GIS analysis

• 1. High‐resolution fishing effort data from the Kattegat, an important fishing ground for Swedish and Danish fishermen, was analysed in a Geographical Information System (GIS). Data were based on position data for individual tows reported by Swedish fishermen during 2001–2003.
• 2. Gear dimension and towing speed data were used to calculate an index for area swept per hour for each main gear type in use in the area. These indexes were multiplied by fishing effort and a grid theme of fishing intensity was created after GIS analysis.
• 3. Around 44% of the entire area was affected by Swedish fisheries during the study period, hence 56% was not affected.
• 4. Effort was highly concentrated in certain areas and 10% of the total area was covered more than twice per year.
• 5. Overlaying the effort data set with habitat maps classified according to the European Nature Information System (EUNIS) showed that the fishing pressure differed between habitats. For deep rocky and muddy habitats, almost the entire area was affected by fisheries during the study period, while both intensity and proportion affected were lower in sandy sediments and gravels.
• 6. Around 55% of the deep rocky habitats were trawled more than twice per year. Of the muddy seafloor areas, 41% were covered more than twice per year and 4% more than once a month by trawls.
• 7. The biological effects of the fishing intensities found were analysed using a database (MarLIN) containing assessments of marine habitat recoverability. All habitats except muds are probably in a nearly or fully recovered condition (as defined by MarLIN). A considerable part of the muddy habitats are in a permanently altered condition owing to fishing disturbance taking place more frequently than the indicated recovery time.
• 8. Danish fishermen report more fishing effort in the area than do Swedes. Owing to differences in reporting fishing positions, Danish fisheries could not be included in the present study. Scaling up the results to include Danish fisheries is discussed.
• 9. The results of the present study could be used to target habitat management goals more precisely, while minimizing the negative impact of restrictions on the fishing sector.
• 10. A prerequisite for performing similar studies is the availability of high‐resolution fishing effort data and high‐resolution benthic habitat maps.

Copyright © 2006 John Wiley & Sons, Ltd.     

Voluntary catch-and-release can generate conflict within the recreational angling community: a qualitative case study of specialised carp, Cyprinus carpio, angling in Germany

Abstract  Because of low fishing mortality that results from catch-and-release angling for carp, Cyprinius carpio L, it is counterintuitive that voluntary catch-and-release (vC&R) of this species induces conflicts within the angling community. Originally motivated by animal welfare concerns, vC&R is today probably as or more strongly criticised within the angling community itself than it is intersectorally. This study reviews the institutional treatment of C&R in Germany and explores within a sociological conflict model the conflicting views surrounding vC&R, specifically in specialised carp angling. It is argued that the intrasectoral (i.e. among angler groups) conflicts around vC&R fishing may divide the recreational angling community, which in turn may weaken the coherence of the entire angling sector. Restricting the opportunity to practice vC&R also can have important social and biological implications, which suggest a rethinking on the current treatment of vC&R recreational angling in Germany.     

中西太平洋延绳钓兼捕大青鲨渔获率、性比及叉长分析研究

大青鲨(Prionace glauca)是一种分布广泛的大型中上层远洋性鲨鱼,在以金枪鱼等经济鱼种为目标的延绳钓渔业中渔获率较高.根据中国远洋延绳钓渔船2015—2018年在中西太平洋(Western Central Pacific Ocean,WCPO)海域共51个航次采集的兼捕大青鲨数据,分析了该海域兼捕到的大青鲨...     

Opportunities and challenges for analysis of wildlife trade using CITES data – seahorses as a case study

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The effects of survey design and circulation pattern on the perceived abundance of herring larvae: a case study for Norwegian spring spawning herring (Clupea harengus)

A larval survey is used in the annual assessment as an index of the spawning stock size of Norwegian spring spawning herring (Clupea harengus). To test how inter‐annual fluctuations in circulation pattern, survey design and execution of the survey affected the larval abundance estimate we conducted simulated surveys using a model framework with idealized assumptions to model larval drift and sampled larvae using several realistic survey scenarios. The results suggest that inter‐annual variations in circulation pattern alone can have a profound effect on the perception of larvae abundance and that the direction of the survey (north to south versus south to north) can have a significant effect on the estimated abundance, particularly if hatching occurs over a short period of time. Additionally, disruptions to a continuous survey schedule also have an effect and, as such, sampling strategies in case of disruption to the survey are proposed.     

The potential of informal institutions for marine fisheries management—A case study of a coastal commune in Vietnam

The potential of informal institutions for sustainable management of marine fisheries was examined. The study is based on both primary data collected through two group discussions and interviews and secondary information, including material related to fishing gear operation and whale worship. It shows that informal institutions, including fisher groups, fishing community norms, fisher's knowledge and whale worship have potential to strengthen institutional, ecological, social and community aspects of sustainable fisheries development. Although these informal institutions are not able to fix completely all the problems faced by formal institutions, they are able to complement and consolidate formal institutions to manage marine fisheries effectively. The findings of this study suggest it is imperative that formal institutions should be improved simultaneously with informal institutions to enhance current management for sustainable marine fisheries development.     

Predicting the age of fish using general and generalized linear models of biometric data: A case study of two estuarine finfish from New South Wales, Australia

Direct ageing of fish can be a laborious and expensive task when age estimates from a large population are required, and often involves a degree of subjectivity. This study examined the application of general and generalized linear models that predict the age of fish from a range of efficiently and objectively measured covariates. The data sampled were from yellowfin bream (Acanthopagrus australis (Sparidae) (Owen, 1853)) and sand whiting (Sillago ciliata (Sillaginidae) Cuvier, 1829) populations from New South Wales, Australia. The covariates evaluated in the models were fish length, otolith weight, sex and location (the estuary from which the fish were sampled). Akaike Information Criteria were used for model selection and residual plots of the final models revealed a satisfactory fit to the observations. The best fitting model for each species included all covariates. An additional investigation considered whether general and generalized linear models that predict age from two different categories of biometric information outperform age-length keys with respect to subsequent estimates of total mortality from catch-curve analysis. The two categories of biometric information differed in the ease and cost with which the information could be collected. The first category only included fish length and location as covariates, whilst the second category also included otolith weight and sex. It was found that traditional age-length keys outperformed the predictive models that estimated age from only fish length and location, because the results from the models were prone to significant bias. However, when otolith weight and sex were added as covariates to the predictive models, some of them, including a generalized linear model with a Poisson-distributed response variable, performed similarly to the age-length key. Given that otolith weight and the sex of fish are cheaper to quantify than age from a sectioned otolith in many situations, general or generalized linear models may represent a cheaper and faster method of estimating mortality compared to age-length keys. Such models can also easily incorporate the influence of spatial, temporal and demographic variation.     

You cannot conserve a species that has not been found: The case of the marine sponge Axinella polypoides in Liguria,Italy

1. Detailed knowledge about the distribution of species in need of protection is required for the management of Marine Protected Areas, a major tool to reduce marine biodiversity loss. Such knowledge is deficient for most marine invertebrates.
2. Axinella polypoides is a marine sponge included on the list of protected species by the Barcelona Convention (1976) and the Bern Convention (1987). This large and erect species has an important ecological role in habitat forming and benthic–pelagic coupling.
3. Bathymetrical, geographical and ecological data over the last 60 years were collated from publications and reports, together with new surveys to assess the distribution and protection status in Liguria of A. polypoides. It identified a more widespread distribution than previously thought, which points at a general need for dedicated investigations on the occurrence of species that require protection.
4. Bathymetrical distribution was trimodal, with peaks corresponding to different geomorphological settings: coastal cliff bases (around 38 m depth), inner shelf shoals (52 m) and rocks amidst coarse sediment on the outer shelf (79 m). Density was significantly greater at the shallowest depths. The species was mostly found in the coralligenous biocoenosis, in association with other characteristic species or forming a monospecific facies.
5. On (sub)vertical cliffs, A. polypoides often exhibited an unusual cane shape, rather than the typical bushy morphology, thus causing confusion with the congeneric A. cannabina, a more southern species. Records of the latter in the Ligurian Sea therefore need confirmation.
6. Only a minority (22.6%) of A. polypoides records were in Marine Protected Areas, the remainder being located in areas with no current environmental protection plans in place. While the occurrence of this species in MPAs remained stable over the decades, the only quantitative historical data available indicated that populations in non-protected areas were declining owing to anthropogenic impacts (fishing and anchoring).

     

A simple model for predicting ecological impacts of introduced aquatic organisms: a case study of common carp, Cyprinus carpio L., in the Sepik-Ramu River Basin, Papua New Guinea

Abstract Practical models for predicting the impacts of introduced biota are urgently required to assess the benefits and risks of introductions. The simple method described predicts the ecological consequences of an introduction through potential competition between species based on elementary niche classifications. The model's predictions are tested against field data for common carp, Cyprinus carpio L., which escaped from fish farms during a study of the feasibility of fish stock enhancement in a large river basin. Recorded effects of carp are based on pre- and post-carp gillnet catches, observations of local villagers, socio-economic censuses and other sources of data. The predicted ecological interactions of common carp are in broad agreement with those recorded. The method can assist pre-introduction assessments and is particularly useful where limited data exist. In this particular study, common carp have contributed significantly to an improved capture fishery by fortuitous accident; production from aquaculture was negligible. High niche overlap between carp and certain resident fish species is predicted and this may be of more consequence in highland than lowland regions. Organisms introduced/transferred for aquaculture should be assessed within a much wider forum. The intended impacts of an introduction/ transfer, which in the case study were entirely erroneous, is an area in need of considerable attention.