Fishing strange data in national fisheries statistics of Greece

Fisheries statistics provided by the Hellenic Statistical Authority (HELSTAT) have been often criticized for unusual estimates in landings and fishing effort data and for limitations in the sampling methodology, although there is no study on the identification of these biased and misreporting estimates. In the present study the landings per species and fishing subarea, as well as the fishing effort data per fishing gear reported by HELSTAT were analysed over the period 1982–2010. The results showed abrupt changes of both the recorded species and species landings per subarea, spurious correlations of landings among different species groups and misreporting estimates in the number of fishing vessels per fishing gear. These might be likely attributed to: (a) differences of the HELSTAT administrative infrastructures at local scale, (b) changes in the sampling protocol followed by HELSTAT, (c) reporting faults made by HELSTAT, (d) fisheries restrictive measures at local basis, (e) other factors that increased the bias and the uncertainties of HELSTAT fisheries data and related to socio-economic (i.e. fuel price) and operational (i.e. spatial structure of the fisheries fleet) aspects and/or (f) to environmental changes that might possibly affected fisheries dynamics. The present study aims to the improvement of the effectiveness of the national fisheries statistics as pinpointed by Common Fisheries Policy in order to avoid imprecise and/or biased estimations about the state of the fisheries.     

Fishing in the past: Historical data on sea fisheries landings in Belgium

In Belgium, centralized reporting on landings of sea fisheries at the species level started in 1929. This paper summarizes the process and the results of integrating time-series, based on fragmented and disperse data sources for the period 1929–1999. The resulting database contains data by species (41), by port of landing in Belgium (4) and in ‘foreign ports,’ and by fishing area of origin (31). After quality control, total reported landings over the period 1929–2008 amounted to 3,320,518 tonnes, of which 90% was landed in the Belgian ports. After a maximum of 75,370 tonnes in 1947, annual landings declined steadily to only 26% of this peak by 2008. Currently, landings are below those achieved in 1929. The most important species in terms of landings (1929–1999) were cod (17% of all landings) and herring (16%). In terms of economic value, sole (31%) and cod (15%) were the most valuable. Close to 73% of all landings originated from 5 of the 31 fishing areas. Twenty percent of all landings (1929–1999) originated from the ‘coastal waters’, while these waters contributed nearly 60% of all landed pelagic species and 55% of all landed ‘molluscs and crustaceans’. Compared to the currently available ICES data, this local database offers advantages in temporal coverage (data from 1929 onwards), temporal scale (monthly values), and at the taxonomic level. It also provides more detailed information at the spatial scale of the southern and central North Sea, and it is the only source of historical information on landings originating from the coastal waters. Given the importance of the shallow and productive ‘Flemish banks’ as a local source of food in historical and recent times, this data is valuable for further research on the productivity of the coastal ecosystem and the local impact of fisheries. The database broadens the historical view on fisheries, underlines the decline in landings since reporting started, and serves as a basis for further (fisheries) research and policy-making in Belgium.     

A software tool for monitoring legal minimum length of landings: Case study of a fishery in southern Spain

The regulation of minimum legal size (MLS) of catches is a tool widely applied in the management of fisheries resources, although the MLS does not always coincide with the length at first maturity (LFM). The optimization of this management tool requires a series of quality control in fish markets and transportation. A software application has been developed to make the control of the landings of several target species easier and faster. In order to test and make this tool operational, six species of commercial interest were selected: four species of fish and two species of bivalves. It is proposed to estimate the proportion of illegal specimens in the studied lot from the proportion of illegal individuals found in the samples taken from this lot. The input data for the application are the minimum legal size (MLS) of the species and the total length (TL) of each specimen sampled. The output data is a statistical summary of the percentage of specimens of size less than the legal minimum (TL≤MLS) within different confidence intervals (90%, 95% and 99%). The software developed will serve as a fast, efficient and easy to manage tool that allows inspectors to determine the degree of compliance on MLS control and to make a decision supported by statistical proof on fishing goods.     

Estimating the economic impact of the Prestige oil spill on the Death Coast (NW Spain) fisheries

This paper presents an estimation of the economic effects of the Prestige oil spill in Galicia, focusing on the Death Coast fisheries and using fish landings as a market technique. Examining the evolution of landings in the Death Coast before and after the accident, the analysis reveals two opposing trends, with landings of some species increasing and those of other species diminishing.     

Changes in fishing behaviour of two fleets under fully documented catch quota management: Same rules,different outcomes

A Dutch pilot study of fully documented fisheries provided the opportunity to observe actual changes in fishing behaviour under catch quota management (CQM). Interviews with fishers in the pilot study aided in interpreting the results and giving insight in the decision making process and reasoning of fishers. The CQM pilot study entailed a fleet of small and large demersal vessels. For these vessels, all cod catches were counted against quota, including catches of individuals below minimum landings size. To obtain reliable catch data all vessels were equipped with electronic monitoring (EM) systems. These systems recorded videos of all fishing and processing activities on board. In return, fishers received a 30% quota bonus for cod and were compensated with more flexibility on effort regulations. It was hypothesized that vessels in the CQM will (i) increase their landings by 30% according to their quota bonus, (ii) increase the use of gear with large mesh size, and (iii) change effort towards fishing locations with high catch rates of large cod and avoid areas with high catch rates of undersized cod. The results showed that CQM had no effect on fishing behaviour of the small vessels. In contrast, large vessels significantly increased their cod landings (216%) and avoided undersized cod. This difference in response of different fleets suggested that implementation of CQM, for instance in the context of the European Common Fisheries Policy, should consider fleet characteristics. It seemed that larger vessels in this study more easily adapted their behaviour to new management regimes and that the quota bonus opened up new fishing strategies, that were not envisaged during the implementation.     

Catch-quota balancing mechanisms in the Icelandic multi-species demersal fishery: Are all species equal?

In this study, utilization of catch-quota balancing mechanisms in the Icelandic demersal fishery, which allow for individual transferable quota to be transformed among species and transferred between years, is analyzed to determine whether annual catches closely adhere to total allowable catches on average. Icelandic landings data for 14 demersal fish species during 2001–2013 are compared to implemented total allowable catches as well as catch limits recommended by the Marine Research Institute (MRI) and a proxy for annual market values. Landings surpassed legal limits of total allowable catch in 27% of the cases (landings by species by fishing year), mostly due to species transformations, but TAC overages were not consistent for any species. Instead, catches of some species were consistently less than legal limits, with some indications that landings were related to profitability (i.e. landings were correlated with market value). However, landings surpassed MRI recommendations in 67% of the cases, and landings of four species (Atlantic wolffish, haddock, monkfish and redfish) consistently exceeded MRI recommendations. Therefore, discrepancies between scientific recommendations for catch limits and quotas selected through the political process may represent a higher risk to long-term sustainability than catch-quota balancing mechanisms.     

A tool for site prioritisation of marine protected areas under data poor conditions

A challenge of managing data poor fisheries lies in overcoming uncertainties associated with a lack of information on biological and socio-economic conditions. This paper focuses on site prioritisation for marine protected areas, a process that usually imposes moderate to heavy demands on data, time, local expertise, and funds. A fuzzy logic decision support tool for zoning marine areas that is suitable for use in data poor conditions is developed. This tool, the Protected Area Suitability Index (PASI), assesses the suitability of sites for protection based on fishers’ preferences for that site and the site’s conservation value. Only eight input attributes are required to run the PASI, which operates on a series of heuristic rules to estimate a site suitability score that ranges from 0 to 10, where 10 indicates that a site is highly suitable for being protected from fishing. Sensitivity analysis reveals that the PASI is relatively robust, and produces reliable results even as the system is degraded by the loss of data. Eighteen actively fished sites and 11 sites that are closed to fishing are assessed to evaluate how well the PASI is able to distinguish differences between sites. The estimated scores are significantly different (p<0.05), whereby non-fished sites are scored as being more suitable for protection than fished sites. The PASI can be used as a decision support tool to facilitate systematic marine spatial management under data poor conditions, especially in the task of identifying suitable sites for protection.     

Performance of a northwestern Mediterranean bottom trawl fleet: How the integration of landings and VMS data can contribute to the implementation of ecosystem-based fisheries management

The European Union has established a framework to achieve or maintain good environmental status in the marine environment by 2020. The Marine Strategy Framework Directive requires the application of the ecosystem approach to the management of human activities, covering all sectors having an impact on the marine environment. However, fisheries in the Mediterranean are far from a systematic implementation of an ecosystem-based fisheries management (EBFM). Aiming to address this issue, this study explores the potential of the relationship between daily yield by vessel (landings and income by species) and vessel position (known via vessel monitoring system) as a tool for fleet management. This approach is possible due to the current dynamics of Mediterranean fleets, with vessels returning daily to the harbour where landings are registered as weight and income by vessel. Moreover, vessels of >15 m total length have been compulsory monitored by VMS since 2005. A bottom trawl fleet that operates in the northwestern Mediterranean was chosen to develop this approach. Different groups of trawlers were identified, which could be linked to the strategies displayed by the fishermen that were mainly driven by the target species dynamics. Accurate knowledge of the fishing targets driving the fleet dynamics and of the fishing strategies at the vessel level (i.e. fishing ground habitat where the fishing pressure is exerted and corresponding landings) are shown to be a feasible tool for fleet management.     

Are critically endangered fish back on the menu? Analysis of U.K. fisheries data suggest post-ban landings of prohibited skates in European waters

Skates (Rajidae) have been commercially exploited in Europe for hundreds of years with some species’ abundances declining dramatically during the twentieth century. In 2009 it became “prohibited for EU vessels to target, retain, tranship or land” certain species in some ICES areas, including the critically endangered common skate and the endangered white skate. To examine compliance with skate bans the official UK landings data for 2011–2014 were analysed. Surprisingly, it was found that after the ban prohibited species were still reported landed in UK ports, including 9.6 t of common skate during 2011–2014. The majority of reported landings of common and white skate were from northern UK waters and landed into northern UK ports. Although past landings could not be validated as being actual prohibited species, the landings’ patterns found reflect known abundance distributions that suggest actual landings were made, rather than sporadic occurrence across ports that would be evident if landings were solely due to systematic misidentification or data entry errors. Nevertheless, misreporting and data entry errors could not be discounted as factors contributing to the recorded landings of prohibited species. These findings raise questions about the efficacy of current systems to police skate landings to ensure prohibited species remain protected. By identifying UK ports with the highest apparent landings of prohibited species and those still landing species grouped as'skates and rays’, these results may aid authorities in allocating limited resources more effectively to reduce landings, misreporting and data errors of prohibited species, and increase species-specific landing compliance.     

Wealth-based fisheries management and resource rent capture: An application to the Maldives marine fisheries

The economic value of marine fisheries can be measured by the resource rent that may potentially be earned, which represents a flow of real wealth for the community at large. For the island state of the Maldives we estimate that the resource rent that could be generated by the marine fisheries is in the order of $50 million per annum, constituting some 27% of the current value of landings. This rent is lost due to the de facto open-access nature of fishing. A wealth-based approach to fisheries management would seek to capture the rent, and the paper discusses the constraints and trade-offs that would be faced in applying this in the Maldivian context. We argue that such an approach is entirely consistent with the aim of the 7th National Development Plan which rightly emphasises the need to ensure the sustainability of marine resources for present and future generations.     

Current and future use of indicators for ecosystem based fisheries management

Implementing ecosystem based fisheries management (EBFM) will require a suite of ecological indices to track the state of an ecosystem, in addition to monitoring species-abundance for both economically important species, as well as species that are not targeted for harvest. However, EBFM implementation requires an examination of current methods and applications of ecological indices that are being used. This paper identifies four key uses for ecosystem indices in the context of EBFM and discusses the implications of each: (1) motivation for socio-political action, (2) information for individual users to modify their behavior, (3) implementation of decision rules for management evaluation, and (4) discovery of ecosystem functions to advance scientific knowledge. In a fisheries management context, ecological indicators will be linked to decision rules based on the definitions of both “ecosystem overfishing” and the current single-species definitions of overfishing. Two components of common ecological indicators are species weightings (i.e. catch or abundance data by species) and the species-specific ecological attributes (e.g. mortality rates, body size, trophic level). We discuss statistical issues that arise from estimating the parameters in ecological index calculations from both fishery-dependent and independent data and the potential biases introduced by using catch-per-unit-effort (CPUE) data, catch data, and abundance estimates. Given the range of biases that arise, often the best estimates of species weightings (abundances) are those derived from fish stock assessments. This implies that progress in EBFM may be best served by increasing the number of species for which single-species assessments are done and to expand the list of species to include species which may not be economically important. The policy framework exists to carry out EBFM; however, future works needs to focus on empirical management strategy simulations, as well as theoretical works to identify management criteria based on those indicators.     

Transdisciplinary co-operation for an ecosystem approach to fisheries: A case study from the South African sardine fishery

Integrative approaches that involve natural and social scientists are needed to manage fisheries, but these are difficult to achieve. The process of developing a prototype, knowledge-based, electronic decision support tool for the South African sardine Sardinops sagax fishery provided a platform for fostering collaboration and achieving active participation of many stakeholders. The aim of the decision support tool is to assist managers in evaluating how effectively an ecosystem approach to fisheries (EAF) has been implemented for this fishery. The collaborative process involved a series of meetings during which knowledge was elicited from fisheries scientists, social scientists, resource managers and fishing industry representatives. Conceptualisations of the different stakeholder perspectives were developed in terms of objectives and indicators following the hierarchical tree approach recommended by FAO. This paper describes the collaborative process. Hierarchies of objectives, indicators and data sets for the human dimension of an EAF in the South African sardine fishery are introduced. The value of a transdisciplinary approach towards an EAF in South Africa is discussed.     

What makes a “successful” marine protected area? The unique context of Hawaii′s fish replenishment areas

In 1998, in order to combat the degradation of yellow tang populations on the west coast of Hawaii Island, fish replenishment areas (FRAs) were established prohibiting aquarium fishing along more than thirty percent of the coastline. Unlike other marine management approaches in Hawaii, which have largely been controversial, fraught with confusion over regulations, inadequately enforced, and lacking public support, these FRAs have been lauded as a marine conservation success, with wide-ranging support and evidence of rapid replenishment of the yellow tang population. In order to better understand the contextual factors contributing to the success of the West Hawaii FRAs, this research explores the following questions: (1) What factors documented in the literature on marine protected areas (MPAs) have been demonstrated to contribute to or inhibit MPA success internationally; (2) which of these factors do the FRAs of West Hawaii exhibit; and (3) are there additional factors that may have contributed to their wide acceptance and success? Common factors contributing to MPA success are determined through a synthesis of the literature. These include: level of community engagement, socioeconomic characteristics, ecological factors, MPA design, governance, and enforcement. The outcomes of West Hawaii′s FRAs are examined in the context of these factors. While the common factors agreed upon in the literature were key to the success of the FRAs, additional contextual factors such as the unique nature of the aquarium fishery and its social marginalization also played a vital role.     

A rejoinder to Shiffman et al., Trophy fishing for species threatened with extinction: A way forward building on a history of conservation

Shiffman et al. assert that International Game Fish Association (IGFA) records are threatening imperiled fish populations. Here I report that 88% of the species identified by the authors were first listed as threatened within the last 20 years and, during this time, IGFA received a total of 15 All-Tackle record applications for these species. The low number of records placed within the appropriate context of total global landings for these species does not support the hypothesis that IGFA All-Tackle records have a disproportionately negative impact on imperiled species as the authors suggest, but rather a disproportionately low impact.     

Private provision of public information in tuna fisheries

Private enumeration of landings data and traceability is an emerging phenomena in developing world tuna fisheries. The general goal of these systems is to facilitate compliance with mandatory market requirements such as the European Union’s Illegal, Unreported and Unregulated fisheries regulation, as well as support aspirations for voluntary requirements such as the Marine Stewardship Council. The long-term success of these systems appears to be dependent on their ability to complement and extend government data and information systems. Developing and maintaining the credibility of these voluntary private enumeration and traceability systems requires strong market incentives as well as strong state support and assurance. If this credibility can be maintained private fisheries information systems may provide a promising basis for innovative stock assessment and management approaches relevant for complex developing world fisheries such as tuna.     

An early footprint of fisheries: Changes for a demersal fish assemblage in the German Bight from 1902–1932 to 1991–2009

Groundfish survey data from the German Bight from 1902–08, 1919–23, and 1930–1932 and ICES International Bottom Trawl Survey (IBTS) quarter 3 data from 1991 to 2009 were analysed with respect to species frequencies, maximum length, trends in catch-per-unit-effort, species richness parameters (SNR) and presence of large fish (Φ₄₀), the latter defined as average presence of species per haul with specimens larger than 40 cm given. Four different periods are distinguished: (a) before 1914 with medium commercial CPUE and low landings, Φ₄₀ ≈ 2, high abundance in elasmobranchs and SNR conditions indicating highly diverse assemblages, (b) conditions immediately after 1918 with higher commercial CPUE, recovering landings, Φ₄₀ at > 4 in 1919, and SNR conditions indicating highly diverse assemblages, (c) conditions from 1920 to the early 1930's with decreasing commercial CPUE, increased landings, decreasing Φ₄₀, SNR conditions similar to later years indicating less diverse assemblages, and a decrease in elasmobranchs. In the IBTS series (d), Φ₄₀ remains low indicating an increased rarity of large specimens, and SNR characteristics are similar to the third period. Dab, whiting and grey gurnard have increased considerably in the IBTS series as compared to the historic data. Φ₄₀ is suggested an alternative indicator reflecting community functional diversity when weight based indicators cannot be applied.     

War,fish, and foreign fleets: The marine fisheries catches of Sierra Leone 1950–2015

In countries like Sierra Leone, where stock assessments based on fisheries-independent data and complex population models are financially and technically challenging, catch statistics may be used to infer fluctuations in fish stocks where more precise data are not available. However, FAO FishStat, the most widely-used time-series data on global fisheries ‘catches’ (actually ‘landings’), does not account for Illegal, Unreported, and Unregulated (IUU) catches and relies on statistics provided by the national agencies of each member country. As such, reported FishStat data is vulnerable to changes in monitoring capacity, governmental transitions, and budgetary constraints, and may substantially underestimate the measure of extracted marine resources. In this report, Sierra Leone's total catches by all marine fishing sectors were estimated for the period 1950–2015, using a catch reconstruction approach incorporating national data, expert knowledge, and both peer-reviewed and grey literature. Results demonstrate that a substantial amount of marine resource exploitation is not represented in official statistics, and reconstructed catches represent more than 2.25 times the recorded FAO Fishstat values. Notably, foreign fleets take the vast majority of industrial catch in Sierra Leone's EEZ, indicating that most of the resource catch and revenue is diverted to foreign companies and export markets. While foreign actors dominate the industrial sector, the small-scale sector represents the majority of domestic catch. Illegal fishing is also a substantial challenge in Sierra Leone, and extracts a large amount of the country's marine fish resources. Reconstructing catches in Sierra Leone also highlights the impacts of various historical events such as Sierra Leone's civil war and post-war reconstruction on the development of the fisheries sector. The results found in the reconstruction present a large discrepancy from FishStat data, with considerable implications for assessment of stocks and management of Sierra Leone's marine resources.     

Contextual factors influencing sustainable fisheries in Mexico

Sustainable fisheries take into consideration that managed fisheries ecosystems shift over time in response to evolving environmental as well as market and political factors. These contextual forces are especially valuable in understanding developing countries such as Mexico, where the unconsolidated fisheries administration faces productive marine ecosystems but unsustainable fisheries. To recognize the issues that have inhibited the consolidation of a regulatory system for sustainable fisheries, a contextual factor analysis was applied to the co-development of two current policies in the Mexican fishery regime: fisheries and environmental policies. Six historical phases have been identified in which there are few long periods of stability and frequent short periods of radical change that alternate between stable and adverse contextual situations. These short and contrasting contextual situations cause a kind of tug-of-war in Mexican fisheries policy-making. On the one hand, domestic economic, scientific, and technological forces seem to slowly lead toward the consolidation of sustainable fisheries; on the other hand, domestic policies drift from one position to another at other timing than the international fisheries and environmental policies. Although recent crises seem to highlight new periods of radical change in Mexico, they also provide an opportunity to adopt new structural plans to consolidate domestic forces as a basis for long-term strategies.     

Global seafood trade flows and developing economies: Insights from linking trade and production

Knowing the patterns of marine resource exploitation and seafood trade may help countries to design their future strategic plans and development policies. To fully understand these patterns, it is necessary to identify where the benefits accumulate, how balanced the arrangements are, and how the pattern is evolving over time. Here the flow of global seafood was traced from locations of capture or production to their countries of consumption using novel approaches and databases. Results indicate an increasing dominance of Asian fleets by the volume of catch from the 1950s to the 2010s, including fishing in the high seas. The majority of landings were by high-income countries’ fishing fleets in their own waters in the 1950s but this pattern was greatly altered by the 2010s, with more equality in landings volume and value by fleets representing different income levels. Results also show that the higher the income of a country, the more valuable seafood it imports compared to its exports and vice versa. In theory, this implies that the lower income countries are exporting high value seafood in part to achieve the broader goal of ending poverty, while achieving the food security goal by retaining and importing lower value seafood. In the context of access arrangements between developed and developing countries, the results allow insights into the consequences of these shifting sources of income may have for goals such as poverty reduction and food security.     

Ensuring appropriate and proportionate responses to environmental threats: A response to Caras and Pasternak

The ecological consequences of coral mining can be severe, with immediate reduction in reef-associated biodiversity and longer term implications for linked habitats such as mangrove forests and seagrass meadows. However, research into the effects of coral mining must take into account other environmental processes which may affect reef communities and the socio-economic context within which coral mining takes place if appropriate and proportionate management responses are to be identified. This article builds upon recently published research detailing the adverse effects of coral mining in Indonesia to illustrate the significance of these points. We use the previous paper to demonstrate that accurate identification of the ecological impacts of coral mining requires the use of appropriate control sites and recognizing natural stresses which may account for short-term variability in ecological parameters. We also underline the need to appreciate that government institutions can directly or indirectly facilitate coral mining, whilst proposed alternative income-generating activities intended to reduce coral mining should be tailored to the local economic, cultural and environmental context if they are to gain community support. This demonstrates the value of an integrated approach to analyzing marine resource usage which combines information from the natural and social sciences to address environmental problems such as coral mining.