Economic dimension of the collapse of the ‘false cod’ Epinephelus aeneus in a context of ineffective management of the small-scale fisheries in Senegal

Small-scale fisheries are often seen as a solution for ensuring sustainability in marine exploitation. They are viewed as a suitable alternative to industrial fisheries, particularly when considering their social and economic importance in developing countries. Here, we show that the booming small-scale fishery sector in Senegal, in the context of increasing foreign demand, has induced the collapse of one of the most emblematic West African marine fish species, a large grouper Epinephelus aeneus, historically called ‘false cod’ by European fishers. The overexploitation of this species appears to be on account of the increasing effort sustained by a growing international demand and important subsidies, which resulted in a relative stability of the average economic yield per fishing trip and an incentive for continuing targeting this species to almost extinction. It is a critical time for addressing and mitigating the pressure of the small-scale fisheries to prevent declines of fish species that are highly valued by northern markets. A balance between conservation and exploitation is necessary to maintain ecological viability while considering the socio-economic importance of the small-scale fisheries. However, a new strategy is needed for conservation that will consider and articulate simultaneously the concerns regarding unmanaged and growing small-scale fisheries, rampant subsidies and increasing foreign demand.     

Determining primary and companion species in a multi-species fishery: Implications for TAC setting

The use of ITQ management in multi-species fisheries has been the subject of much debate and the complexities and difficulties of managing multi-species fisheries are well known. A major problem is that the species mix in fishery catches may not necessarily match the mix in combined TACs or in quota holdings. While a number of solutions have been proposed or implemented to improve transferability of quota and other incentives to reduce over-quota fishing and discarding, it is surprising that there has been little focus on TAC-setting itself and coordinating this across multiple species/stocks as a means of dealing with some of these issues. In this paper, data were analysed from the trawl sector of the Australian Southern and Eastern Scalefish and Shark Fishery to determine the relationship between primary species and companion species and the implications this has for TAC setting. The primary species is the species being considered when setting an individual species TAC. The companion species are ones that should also be considered when setting the TAC of the primary species, because a considerable proportion of the primary species catch is taken as a companion species non-target catch. The target species in each fishing operation was determined and was used to characterize recent multi-species catch data into primary and companion components. This approach provides an empirical means to examine the impact of individual species TAC decisions across all of the quota species in a fishery.     

Dysfunction by design: Consequences of limitations on transferability of catch shares in the Alaska pollock fishery

The Eastern Bering Sea fishery for pollock is one of the largest fisheries in the world and has often been touted as an example of sustainable fisheries management. Yet, sustainability requires more than protection of the biological productivity of the targeted fish species. It requires preservation of the flows of net social and economic benefits of the fishery, and flexible governance and management institutions that allow for adaptation to changes in fish abundance as well as changes in consumer demand and in the prices of key inputs. From an economic perspective, the Alaska pollock fishery was unsustainable before passage of the American Fisheries Act (AFA) in 1998. The AFA permanently divided the pollock Total Allowable Catch (TAC) giving a 10% allocation to the Community Development Quota (CDQ) program and partitioning the remainder among four fishing sectors. It allowed CDQ to be leased to any sector but largely prohibited leasing or sale between other sectors. These limits on intersectoral transfers have reduced the ability of sectors to respond to changes in the abundance and distribution of pollock, implementation of management measures intended to benefit other species, and changes in the prices of input factors and products. This paper explores these consequences.     

Fish species diversity in the Huanghe Estuary

I~IOXThe Huanghe River is among the largest rivers in the world. It is the cradle of the ChineseciviliZation, and haS a great importance in fisheries. There were some studies on the HuangheRiver fisheries, such as the Repert of the Basic Fishery Biological Su~ of the Huanghai Riber(Anon, 1960), The Fishery Resources Of the Huanghe Riber System (Anon, 1986a). With regard to the fish species diversity in the Huanghe Estuary, there were only some general information from Read of Ichth…     

台湾海峡及其邻近海域鱼类生活史特征及其变化研究

世界范围内,海洋渔业资源广泛面临着过度捕捞的压力.鱼类的不同生活史特征可表征不同的生活史对策,其变化可揭示鱼类种群对渔业捕捞压力的响应.台湾海峡及其邻近海域的主要渔场30多年来面临着过度捕捞的压力,导致了鱼类群落结构发生改变.本研究分析了该海域51种主要经济鱼类的生态参数,系统研究了其生活史特征及其变化.采用主成分分析法可将51种鱼类分成5个不同的生活史对策组,分组结果表明超过60%的鱼类被归纳入第5组,即近r对策组,且多为中上层鱼类.在此基础上收集相关历史数据,对其中25种经济鱼类进行生活史变化分析,讨论不同鱼类种群对渔业开发的响应.分析结果表明,在长期的渔业开发活动下多数鱼类表现出小型化、低龄化、早熟和生长率加快等趋势.此外,本研究计算了每种鱼类的开发率以进一步研究渔业捕捞压力对鱼类种群的影响,发现其中4种底层和近底层鱼类的生活史特征变化显著,提示某些物种可能对捕捞压力更敏感.本研究可为渔业管理和保护提供重要的科学依据.     

Reef fish display station-keeping and ranging behaviour in the Pondoland Marine Protected Area on the east coast of South Africa

This study assessed the role of the Pondoland Marine Protected Area (MPA) in the Eastern Cape province of South Africa by evaluating retention versus ‘spillover’ of exploited fishery species that were tagged in a 400 km² no-take zone of the MPA. From April 2006 to July 2010, 2 124 fish comprising 36 species were tagged in the MPA, with an overall recapture rate of 23%. Findings for four important species (Polysteganus praeorbitalis, Chrysoblephus puniceus, Epinephelus andersoni and Epinephelus marginatus) are presented. Recapture rates ranged from 8% to 60% and time-at-liberty from 0 to 1 390 d. Individuals of all four species displayed highly localised station-keeping behaviour. For all four species, the 95th percentile of intra-study site movements was <750 m (linear distance) and many recaptures were within 250 m of the release site, showing that some fish spend most of their time in the MPA's no-take zone. However, some fish moved beyond the boundary of this zone in a north-easterly direction (range 3–1 059 km), where they would be available to the boat-based fishery in KwaZulu-Natal. The combination of resident individuals with some with ranging behaviour suggests that the MPA can provide a conservation role for these species, while exporting some individuals into nearby fisheries.     

Free form property rights for fisheries: The decentralized design of rights-based management through groundfish “sectors” in New England

Harvest cooperatives were implemented in several US fisheries over the last decade during a period when US law prohibited implementation of any new individual fishery quota (IFQ) systems. Harvest cooperatives provided an alternative to individual quotas as a means to end the race for fish and increase fishery profitability. The prohibition on new IFQ systems in the US was lifted, but harvest cooperatives remain a more feasible and perhaps a superior alternative to IFQs for some fisheries. The New England Fishery Management Council is on the verge of implementing a new management system for the groundfish fishery based on harvest cooperatives known as “sectors”. This paper describes the New England sector management system and discusses a number of advantages but also some drawbacks relative to IFQs. It argues that a hybrid of the two approaches could have advantages over either.     

Eco-labeling seafood: Addressing impacts to vulnerable seafloor species,communities, habitats and ecosystems in data-poor regions

Certification and eco-labeling schemes for the ecological sustainability of seafood have increased in recent years due, in large part, to consumer demand. While most attention has been focused on the population status and trends of target and bycatch species, the conservation of vulnerable species, communities, habitats and ecosystems (VSCHEs) has not consistently been addressed in an adequate manner, especially in data-poor systems. Unfortunately knowledge of VSCHE distribution patterns is inadequate, and even the leading fishery certification agencies only broadly address impacts to VSCHEs. Little guidance has been given to third party certifiers for gathering and evaluating appropriate information for assessing VSCHEs, and there is no explicitly precautionary method of assessing their vulnerability in an information poor environment. These shortcomings led to significant differences in how the impacts of fisheries on VSCHEs have been evaluated from one assessment to another, potentially resulting in a certified fishery when existing information suggests there are significant impacts. This study develops an explicit approach for data mining and evaluation for the eco-labeling certification process; proposes a precautionary method for assessing vulnerability of VSCHEs based on exposure, sensitivity and resilience and provides an example of how these can be integrated into existing fishery certification frameworks. This overall approach is also amenable for use by governmental agencies to advance conservation of VSCHEs within ecosystem-based management frameworks.     

A decade of exploitation and management of the Namibian hake stocks

The hake resource is the most important commercial fish species in the demersal sector of Namibia's fisheries, both in terms of annual catch and contribution to Gross Domestic Product (GDP). The fishery now spans four decades. In the 1960s and 1970s, hake were exploited heavily by mainly foreign fleets, total catches peaking at more than 800 000 tons in 1972. The first control measures, the use of a minimum mesh size of 110 mm and the allocation of quotas to each member country participating in the hake fishery, were implemented by the International Commission for the Southeast Atlantic Fisheries in 1975. In 1990, the Namibian Government took action to control fishing activities in Namibian waters, and the enactment of its Fisheries Policy (1991) and Sea Fisheries Act of 1992 provided for the control measures to be taken. The conservative management strategy adopted between 1990 and 1993 resulted in gradual increase in hake biomass, but thereafter the stock declined. The hake fishery is currently managed on the basis of a total allowable catch that takes into consideration the rate of increase or decrease in the size of the resource. Since 1990, the demersal trawl fishery has accounted for approximately 90% of the total hake catch. The resource is subjected to both directed fishing and bycatch, the latter taken in directed fisheries for species such as horse mackerel, monkfish and sole.     

福建三沙湾游泳动物种类和数量的季节变化

根据2019年1月、4月、7月和10月四个季度10个站位定置张网调查资料, 对福建三沙湾游泳动物的种类组成及季节变化进行分析研究。结果表明: 调查共获得游泳动物209种, 隶属于3门4纲19目73科144属, 其中鱼类154种, 甲壳类48种, 头足类7种。游泳动物种类数以秋季出现最多, 四个季节共同出现的种类有42种。鲈形目种类最多, 其次是十足目。鱼类适温性以暖水性种类居多, 占71.43%, 暖温性种类次之(27.92%); 生态类型以底层、近底层鱼类居多, 两者合占75.97%。鹰爪虾(Trachypenaeus curvirostris)、大黄鱼(Larimichthys crocea)、棘头梅童鱼(Collichthys lucidus)、红星梭子蟹(Portunus sanguinolentus)和日本蟳(Charybdis japonica)等14个种类是三沙湾游泳动物的优势种类, 季节性优势种居多。三沙湾定置张网调查渔业资源质量密度为111.09 kg/km², 尾数密度为13.72×10³ ind./km², 均以夏季最高, 春季最低。应该进一步加强对三沙湾渔业资源的合理利用和有效保护, 同时重视对外来物种的监测。     

Measuring management success: Experience with United States fisheries

Many articles have been published in recent years criticizing the management of living marine resources based solely on biological stock conservation criteria. In the United States and in many parts of the rest of the world, multiple management objectives and goals in addition to stock conservation must be met by fishery managers responsible for the marine resources under their control. An alternative management metric, conservation efficiency, is recommended based instead on a multi-disciplinary scientific framework that captures these different goals and the behavior of participants in the fishery. On the basis of the constraints facing managers, resources can be conserved and the quality of life of consumptive and nonconsumptive fishery participants improved.     

The transition from the Soviet system to a market economy as a cause of instability in the Estonian coastal fisheries sector

This study analyzes how overall changes in political and economic life during the last decade have affected the Estonian coastal fishery of the Baltic Sea. At the beginning of the nineties, the opportunity to export fish to the European market emerged. Opening of this new market resulted in rapidly increasing pressure on fish stocks. Some of the most important coastal fishery resources were over-fished because of high export market demand coupled with insufficient resource management and ineffective control and enforcement mechanisms. The costs associated with fishery have grown much more than the first-buyer prices. Additionally, dynamic development of the Estonian economy has resulted in substantial increases in earnings in other economic sectors and therefore the relative wealth of fishermen has steadily declined. This has resulted in increasing social problems. In conclusion, countries in transition may encounter serious difficulties in the fisheries sector, arising from privatization and economic reforms, which may affect the fisheries even years after the establishment of new ruling principles.     

Choosing a fishery’s governance structure using data poor methods

Multi-species fisheries are complex to manage and the ability to develop an appropriate governance structure is often seriously impeded because trading between sustainability objectives at the species level, economic objectives at the fleet level, and social objectives at the community scale, is complex. Many of these fisheries also tend to have a mix of information, with stock assessments available for some species and almost no information on other species. The fleets themselves comprise fishers from small family enterprises to large vertically integrated businesses. The Queensland trawl fishery in Australia is used as a case study for this kind of fishery. It has the added complexity that a large part of the fishery is within a World Heritage Area, the Great Barrier Reef Marine Park, which is managed by an agency of the Australian Commonwealth Government whereas the fishery itself is managed by the Queensland State Government. A stakeholder elicitation process was used to develop social, governance, economic and ecological objectives, and then weight the relative importance of these. An expert group was used to develop different governance strawmen (or management strategies) and these were assessed by a group of industry stakeholders and experts using multi-criteria decision analysis techniques against the different objectives. One strawman clearly provided the best overall set of outcomes given the multiple objectives, but was not optimal in terms of every objective, demonstrating that even the “best” strawman may be less than perfect.     

Social,economic and environmental effects of closing commercial fisheries to enhance recreational fishing

Recreational fishing mortality can have a major impact on coastal fish populations, bringing recreational fishers into conflict with commercial fisheries. This article reviews exclusion zones for commercial fishing, or ‘recreational fishing areas’ as a solution to the conflict between commercial and recreational fisheries. Recently designated recreational fishing areas in the state of Queensland, Australia are examined as a case-study. The goal of recreational fishing areas is to enhance recreational fishing and provide economic opportunities through charter fishing. However, recently designated recreational fishing areas in Queensland have not been thoroughly assessed for their social, economic and environmental impacts and they are not integrated within existing management frameworks for fisheries. The designation of recreational fishing areas is thus a shift away from evidence-based management in Queensland's fisheries and has likely occurred solely for political reasons – there are more voters in the recreational fishery than commercial fishery. In Queensland, excluding commercial fishing on its own is unlikely to result in long-term benefits to recreational fisheries because recreational harvest is a major component of fish harvest for some key species and there is no legislated limit to recreational harvest. Current political attention on recreational fishing areas provides an opportunity for fisheries managers, politicians, conservation groups and the public to discuss what is needed to manage sustainable coastal fisheries. In particular, recreational fishing areas need to be combined with efforts to enhance stewardship among recreational fishers if they are to be successful in the long-term.     

Estuarine and coastal connectivity of an estuarine-dependent fishery species,Pomadasys commersonnii (Haemulidae)

Understanding the level of connectivity between estuarine and coastal waters is essential for appropriate management of estuarine-associated taxa. Most studies have focused on the role of a single estuary, while limited research exists on the importance of multiple estuaries to individuals of estuarine-associated species. This study used acoustic telemetry to assess the usage of multiple estuaries and coastal waters by the estuarine-dependent spotted grunter Pomadasys commersonnii. Twenty-six adult fish were tagged with acoustic transmitters in the Kariega and Bushmans estuaries, South Africa, and their movements along a 300-km stretch of Indian Ocean coastline were monitored for up to 17 months. Tagged individuals spent most of their time in the estuary where they were tagged (55% and 85% for fish tagged in the two estuaries, respectively), followed by time in the sea (30% and 15%) and in other estuaries (15% and <1%). The mean durations of sea trips for fish tagged in the Kariega Estuary or Bushmans Estuary, respectively, were 25 days (range 3–55) and 12 days (range 2–22). Of the fish that went to sea, 93% from the Kariega Estuary and 60% from the Bushmans Estuary visited other estuaries. Most visits were undertaken to the Swartkops, Bushmans and Kowie estuaries, although the longest durations were spent in the Sundays Estuary. Individuals moved to estuaries up to 130 km away. The total distance travelled between estuaries by an individual during the study was ～529 km, with means of 201 and 184 km, respectively, for fish tagged in the Kariega and Bushmans estuaries. Despite covering large distances between estuaries, individuals often returned to their tagging estuary. Residency in their tagging estuary, combined with frequent visits to a neighbouring estuary, highlights the importance of estuarine habitats for this popular fish species, even after reaching maturity.     

Ocean robotics in support of fisheries research and management

South Africa’s small-pelagic fishery is a socio-economically important component of the country’s commercial fisheries sector, second in value only to the demersal trawl fishery. Management of this sector relies on infrequent hydro-acoustic surveys, which provide measures of anchovy Engraulis encrasicolus and sardine Sardinops sagax biomass used in the assessments of stock status and in the development of management plans for the sustainable utilisation of these resources. We demonstrate how technological capabilities in ocean robotics at the Council for Scientific and Industrial Research (CSIR) could augment the current resource-intensive hydro-acoustic ship-based survey programme and create opportunities for expanding its spatial and temporal resolution. We successfully implement and demonstrate an autonomous wave glider, fitted with a hydro-acoustic sensor and compare the data to a collocated ‘traditional’ ship-based acoustics survey. In the future these autonomous systems approaches could be seen as a means to lessen the cost burden of the ship-based survey, while at the same time with the added advantage of continuous collection over much wider spatial and temporal domains. This could enable a more reflexive stock management approach taking into account the seasonal characteristics of the fishery and its ecosystem. Gliders thus have potential to increase dramatically the quantity of information available to fisheries managers, thereby reducing uncertainty and contributing to improved management of valuable fish resources. They are likely to contribute to improved knowledge of the ecology of small pelagic fish species off the coast of South Africa in a changing climate and should potentially also permit the collection of biomass data for other marine resources currently not routinely monitored.     

Sea turtle bycatch to fish catch ratios for differentiating Hawaii longline-caught seafood products

Sea turtles can be incidentally caught in pelagic longline fishing gear targeting tuna and swordfish. Bycatch to fish catch (B/C) ratios can differentiate seafood based on sea turtle impacts. This study demonstrates the use of B/C ratios indexed to the weight of fish catch: (1) to report on the significant progress in reducing sea turtle bycatch in Hawaii's swordfish longline sector and (2) to compare Hawaii and other Pacific longline fisheries by number of sea turtle interactions per weight of catch. Hawaii's longline tuna fishery sets the benchmark of 1 sea turtle interaction per 190,000 kg of tuna caught.     

Heterogeneous management and conservation perceptions within the gooseneck barnacle co-management system in Asturias (N. Spain)

Stakeholders’ perceptions can influence the success of a fishery. It is important to take these perceptions into account when evaluating the development of a management system and its conservation policies. Structured questionnaires were used to determine fishers’ management and conservation perceptions of the Asturian gooseneck barnacle co-management system. Perceptions were analyzed for the entire fishery and for different socioeconomic factors, these were: location, age, years in the management system, way of access, alternative income sources and income. Fishers’ perceptions varied widely among socioeconomic factors. In fact, a trade-off between management and conservation perceptions was observed for the different categories within each socioeconomic factor, particularly for the years in the management system, location and income factors. Despite the heterogeneity in perceptions, the co-management system has successfully generated a strong conservation ethic in its resource users. Furthermore, as a group, gooseneck barnacle fishers hold positive perceptions on the performance of the management system. When generating management policies, fisheries’ managers must take the heterogeneity of resource users present in the fishery into account. The gooseneck barnacle co-management system demonstrates that even within the same fishery there can be multiple paths to sustainability.     

A new species of electric ray of the genus Narcine Henle, 1834 from the South-Western Indian Ocean (Chondrichthyes: Torpediniformes: Narcinidae)

The Namibian linefishery is a multisector fishery, with recreational and commercial sectors targeting overlapping species. Prior to 1990, catch data were recorded for the boat sector, but little research was done on the population dynamics of any of the species. Hence, none of the stocks were assessed owing to the lack of parameter estimates for fisheries modelling. Current management regulations for the Namibian linefishery are therefore not based on scientific investigations but, for historical reasons, were adapted from South African legislation for similar species. From 1994, linefish research in Namibia focused on the life history and population dynamics of silver kob Argyrosomus inodorus and West Coast steenbras Lithognathus aureti, important species in both commercial and recreational sectors. A roving-roving creel survey was used to determine effort and catches of recreational shore-anglers. Both species were assessed using yield-per-recruit models. Based on the results, reduced daily bag limits and the implementation of size limits for the recreational sector were proposed. For the commercial sector, the introduction of a total allowable catch would seem to be the best option. Results from an economic survey indicated that the recreational sector earns six times more for the country annually than the commercial sector.     

An assessment of the recreational fishery in the St Lucia estuarine system,KwaZulu-Natal,South Africa

St Lucia is one of the largest estuarine systems in Africa, and attracts thousands of anglers each year. Catchcard data from the National Marine Linefish System for the years 1986–1999 were analysed to determine catch composition, catch per unit effort (cpue) and seasonality of catches by recreational anglers. Because not all anglers completed catch cards, estimates of total catch were made using additional data on the number of private boat outings, the number of boat trailers at boat slipways and the number of boats recorded entering the campsite gates during 1992 and 1993. In all, 27 fish families, constituting 55 species, were recorded by recreational anglers. Dusky kob Argyrosomus japonicus, spotted grunter Pomadasys commersonnii, perch Acanthopagrus berda, Natal stumpnose Rhabdosargus sarba, springer Elops machnata and mini-kob Johnius dorsalis were the most prominent species caught in terms of numbers and mass. Catch rates expressed numerically (fish angler^?1 h^?1) peaked during the summer and early winter. However, in terms of mass, catch rates peaked during late winter and spring, when there were increased landings of large dusky kob. Fluctuations in cpue were linked to salinity and estuary mouth conditions (i.e. mouth closure). Despite annual fluctuations in cpue, regression analysis revealed an overall downward trend for the dominant species (dusky kob and spotted grunter) and a gradual increase for stumpnose, perch and springer, but with the exception of stumpnose, these trends were not significant. Socio-economic aspects of the fishery were also investigated by conducting an independent boat-angler survey. The value of the recreational fishery, in terms of accommodation and direct angler expenditure, was estimated to be in the region of R9 million during 1992. Angler attitudes towards fishing regulations were positive and anglers generally had a good knowledge of the regulations for target species. Based on this assessment, a number of suggestions are made regarding the future management of the recreational fishery at St Lucia.