Search

Recreational spearfishing is a fishing method that occurs globally, yet receives considerably less attention in the scientific literature relative to other recreational fishing methods, such as angling. Lack of scientific information on spearfishing may negatively affect the development and management of marine recreational fisheries. We conducted a systematic review of 102 peer-reviewed papers published between 1967 and 2022 pertaining to marine recreational spearfishing. Based on this literature review, we provide an overview of key insights across social, economic, and ecological dimensions of marine recreational spearfishing. While spearfishers represent less than 5% of marine recreational fishers, the participants are younger and may differ from recreational anglers in their motivations, with suggestions of increased well-being generated from a close connection with the sea during underwater fishing. Recreational spearfishers mostly target species of moderate to high levels of vulnerability that are mid to high trophic level carnivores. Though spearfishers can deliberately target larger individuals of exploited populations, this is not a generalizable pattern. Despite a growing body of research on the ecological impacts of marine recreational spearfishing, there is limited knowledge of these effects and their mechanisms across biological levels of organization (e.g., individual, population, community and ecosystem) compared with those of other fishing methods. Recreational spearfishers can contribute to advances in marine ecological knowledge, and inclusive participatory management could represent a key step towards transformative sustainable development of marine recreational spearfishing. Throughout the review, we identify gaps in the research and areas where future research is needed to better inform the socio-economic importance, ecosystem impacts and future management of marine recreational spearfishing. [ABSTRACT FROM AUTHOR]

The spatial distribution patterns of Merluccius capensis in the Namibian waters were investigated and related to average environmental conditions during 1996–2020. Fisheries‐independent data and simultaneously collected water temperature and dissolved oxygen data were used from austral summer surveys. A geostatistical kriging approach was employed to evaluate the spatial structure of hakes. Links to environmental conditions were explored via data‐driven generalized additive models (GAMs). M. capensis generally exhibited average patch sizes between 40 and 50 nm at depths between 180 and 280 m. During the extreme episodic water warming in 2011 related to a Benguela‐Niño, the hake patches shrank up to a historical minimum of about 13 nm and moved offshore showing maximum densities at unusual deeper bottoms between 260 and 320 m. The deepening and size reduction of aggregations did not alter the biomass estimates (570 kt) that remained within historical ranges (249–811 kt). Although other extremely warm and cold summers were reported during the study period, no significant impact on the M. capensis patch size was detected. Maximum M. capensis densities were linked to optimal bottom temperature range between 10.1 and 11.8°C, dissolved oxygen values close to zero nearshore, and between 0.8 and 1.4 ml/L offshore. Potential changes of biomass produced by extreme environmental events remained undetected within the interannual biomass ranges, suggesting a high resilience capacity to episodic extreme environmental events. [ABSTRACT FROM AUTHOR]

Highlights • This is the first Spanish nationwide study addressing marine recreational fishing. • The official Spanish recreational fisher population is provided for the first time. • Estimates of CPUE, effort and total catch are given for each modality. • Recreational fishers' social profile and satisfaction levels are analyzed. • Different dissemination strategies have had ranging success rates. Abstract This study represents the first nationwide assessment of marine recreational fishing in Spain. A new cost-effective approach was used to collect fisher's information: an online application adapted to different platforms was kept operative from February 2016 to February 2017. Commercial and non-commercial dissemination campaigns represented substantial differences in their success rate and cost-effectiveness. In this study, fisher's population size, profile and fishing activity were analysed for shore fishing, boat fishing and spearfishing independently in each of Spain's Autonomous Communities (AC). The official recreational fishing population according to the license registries reported by the AC is of 871,533 fishers, but this study reveals that around 5% of fishers are unlicensed. The most popular modality was shore fishing (83.6% to 67% of recreational fishers) followed by boat-fishing (11% and 31%) and spearfishing (1.2% to 4.9%). The mean age varied significantly between modalities: 36 years for spearfishing, 41 years for shore fishing and 45 years for boat fishing. The education level of spear-fishers and boat-fishers were both higher than that of shore-fishers, which had the highest levels of unemployment. Fisher satisfaction levels of the activity and the catch were high for every modality and AC. Interestingly, a 94% of our respondents declared that their catch was for household consumption. Catch rates differed significantly between fishing modalities: shore fishing had the lowest catch rates (1.17 kg d−1s.e. 0.028), followed by spearfishing (2.02 kg d−1 s.e. 0.044) and boat fishing (2.91 kg d−1 s.e. 0.78). Estimates of annual fishing days (shore fishing 60.6 d y−1 s.e. 0.67; boat fishing 57.1 d y−1 s.e. 0.092; spearfishing 51.5 d y−1 s.e. 0.71) did not differ from those of previously published studies using onsite surveys in the same regions, despite the fact that our sample could be potentially over-representing avid fishers. The implications of misestimating annual effort and its importance on MRF impact are also discussed. [ABSTRACT FROM AUTHOR]

Marine recreational fishing (MRF) is a high-participation activity with large economic value and social benefits globally, and it impacts on some fish stocks. Although reporting MRF catches is a European Union legislative requirement, estimates are only available for some countries. Here, data on numbers of fishers, participation rates, days fished, expenditures, and catches of two widely targeted species were synthesized to provide European estimates of MRF and placed in the global context. Uncertainty assessment was not possible due to incomplete knowledge of error distributions; instead, a semi-quantitative bias assessment was made. There were an estimated 8.7 million European recreational sea fishers corresponding to a participation rate of 1.6%. An estimated 77.6 million days were fished, and expenditure was €5.9 billion annually. There were higher participation, numbers of fishers, days fished and expenditure in the Atlantic than the Mediterranean, but the Mediterranean estimates were generally less robust. Comparisons with other regions showed that European MRF participation rates and expenditure were in the mid-range, with higher participation in Oceania and the United States, higher expenditure in the United States, and lower participation and expenditure in South America and Africa. For both northern European sea bass (Dicentrarchus labrax, Moronidae) and western Baltic cod (Gadus morhua, Gadidae) stocks, MRF represented 27% of the total removals. This study highlights the importance of MRF and the need for bespoke, regular and statistically sound data collection to underpin European fisheries management. Solutions are proposed for future MRF data collection in Europe and other regions to support sustainable fisheries management. [ABSTRACT FROM AUTHOR]

Intentional mislabelling of seafood is a widespread problem, particularly with high-value species like tuna. In this study we examine tuna mislabelling, deliberate species substitution, types of substitution and its impact on prices. The survey covered the commercial chain, from Merca-Barna to fishmongers and restaurants in the Spanish Autonomous Community of Catalonia. To understand the geographic extent of the problem we also sampled Merca-Madrid, Europe’s biggest fish market, and Merca-Málaga for its proximity to the bluefin tuna migratory route and trap fishery. Monthly surveys were carried out over one year. The results showed a high deficiency in labelling: 75% of points of sale and 83% of restaurants did not specify the species, and in those cases the name of the species had to be asked. A total of 375 samples were analysed genetically, the largest dataset gathered in Europe so far. The identified species were Thunnus albacares, Thunnus thynnus and Thunnus obesus. Species substitution began at suppliers, with 40% of observed cases, increasing to 58% at fishmongers and 62% at restaurants. The substitution was mainly on bluefin tuna (T. thynnus), 73% of cases. At restaurants, only during the bluefin fishing season, we observed a decrease of Bluefin tuna substitution and an increase of reverse substitution revealing some illegal fishing. The effect of species substitution on species prices was relevant: T. obesus increased its price by around €12 kg-1 when it was sold as bluefin. In view of the deficiency of labelling, the abuse of generic names and the lack of the bluefin catch document, we conclude that the Spanish regulations are ineffective, highlighting the need for policy execution, and the urgent need for information campaigns to Spanish consumers. [ABSTRACT FROM AUTHOR]

Fish farms have been shown to aggregate large numbers of wild fish in their surroundings. Although little is known about how this affects the local fishery, two hypotheses have been put forward; a trapping and a protecting effect on wild fish. This study provides the first monitoring of commercial and recreational fishing activity at a fish farm. We assessed the effect on the small-scale fishery analysing the differences between fishing in farm proximity and away from the farm (in terms of catch rate, income and catch composition). Moreover, we estimated the biomass removal from fishing activities by farm employees inside the farm. The study was conducted from January 2011 to June 2012 at a Gilthead seabream farm in the NW Mediterranean. The findings revealed a relevant amount of commercial and recreational fishing effort in farm proximity. Yet, the results showed no benefit or difference of fishing in close proximity to the farm compared with areas away from the farm. Thus, we conclude that farm-aggregated fish are protected from the commercial fleet by the farm leasehold area, but remain vulnerable to hidden fishing practices inside the farm, where farm employees harvest more than 4 t of wild fish annually. [ABSTRACT FROM AUTHOR]

This study presents the first results on Atlantic bluefin tuna (Thunnus thynnus) individual spawning duration and its short-term temporal behavior. The study was based on direct measurements resulting from mtDNA analysis of the offspring of spawners held in transport cages during the 2013 spawning monitoring survey in Balearic waters. The number of females consisted of approximately 259 individuals with an average weight of 186 kg. The survey began on May 22 and ended on July 3. Spawning started on May 30 and was observed every night afterwards. The sampling of eggs for genetic monitoring was conducted for 9 days interspersed from the beginning of spawning to the end of the survey. A total of 946 eggs were analyzed and revealed 129 different haplotypes; 77 of these were not previously detected in the Mediterranean. A total of 69 haplotypes were observed in more than one spawning event and those with higher frequency lasted their maximum possible duration. The haplotypes present at the beginning of spawning were also identified at the end of the sampling, indicating a minimum spawning duration of 34 days, and individual annual fecundity was estimated at around 1290 eggs gr-1. These results differed from those generally presumed until now and are indicative of a much higher fecundity. Females exhibited a regular spawning schedule but with the capacity to shift the spawning hour during the spawning season. These results were observed for the eastern population of Atlantic bluefin tuna and before extrapolating to the western population, their validity should be proved. [ABSTRACT FROM AUTHOR]

Factors influencing within-farm variability of wild fish aggregations have not been systematically studied. We tested the hypothesis that fish abundance and species composition vary between feeding and non-feeding periods and different bottom substrates within a Sparus aurata ( L.) farm. Sampling took place during feeding and non-feeding periods on six consecutive days in July 2011. Visual censuses were carried out at three different depths and at three sampling stations over rocky-sandy and sandy substrates respectively. In all, 33 species belonging to 17 families were observed. Total fish abundance, biomass and species community significantly differed between feeding and non-feeding periods. Each depth was represented by a distinct species community and was therefore affected differently by the feeding activity. At the surface, fish abundance was significantly higher during feeding compared with non-feeding periods. The distance from the feeding vessel significantly influenced fish aggregations in the water column, indicating that planktivorous species learnt to associate the boat noise with food availability through classic conditioning. At the bottom, substrate type was the dominant factor explaining aggregation variability. This study provides new information about the dynamics of fish aggregations within farms, emphasizing the importance of considering the different sources of variability in future study designs. [ABSTRACT FROM AUTHOR]

Abstract: Marine aquaculture production is becoming increasingly important to meet global seafood demands. Conversely, there are concerns about potential environmental impacts, especially associated with marine fish farming, and the access to and use of coastal resources. While only a small number of studies on social acceptability of fish farming exist, understanding the range of perceptions among social groups is a key challenge for successful management of aquaculture, and thus for sustainable development. The case study presented here uses the Q-methodology to explore the perceptions of five aquaculture-related key stakeholder groups (NGOs, local fishermen, fish farming industry, scientists and regional administration) towards marine fish aquaculture in Catalonia (NE Spain). The 30 participants were asked to sort 39 statements about environmental, social and economic aspects of marine fish farming, on a scale from strongly agree to strongly disagree. The factor analysis identified four distinct factors, each representing a different perception. While Perception 1 regards fish farming as an activity with important socio-economic benefits and low environmental costs, Perception 2 gives highest importance to environmental concerns. Perception 3 represents a more balanced view, valuing the socio-economic benefits and expressing moderate concern about environmental impacts, whereas Perception 4 focuses mainly on economic aspects. Interestingly, the four perceptions were represented by various groups of stakeholders and not all respondents from the same sector shared the same perception. This study contributes to the scarce scientific information on social research on aquaculture, revealing limitations, challenges, and opportunities of the industry. [Copyright &y& Elsevier]

This study analysed the temporal pattern of Atlantic bluefin tuna (ABFT) spawning in the Balearic spawning ground and examined its reproductive performance after years in captivity. Furthermore, ABFT hatching time at different on-site temperatures was determined for the first time. Spawning surveys were carried out in 4 spawning seasons (2009–2012) aboard tuna transport vessels. Three groups of spawners were monitored: a captive group transported to the spawning region and monitored throughout the four spawning seasons and two wild groups caught in 2009 and 2010 which were transferred to a monitoring transport cage immediately after being caught. Surface plankton samples were collected nightly, beginning immediately after the first purse seine catches were made and concluding after spawning was observed to have ended. All groups displayed the same spawning hours, restricted between 2:00–5:00 a.m. The captive group, as they got older, shifted towards the earliest hour, suggesting an age influence on reproductive time. The onset of spawning varied annually from the end of May to the beginning of June at temperatures around 19°C–20°C, ending by the second week of July. The peak of spawning was consistently around the summer solstice, June 15th–30th. The results showed the negative effect of unstable oceanographic conditions in the spawning process which might influence the annual reproductive success of ABFT. The influence of temperature on hatching time was higher than that observed in other tuna species, twice as fast at 26°C (23 h) as at 19.5°C (49 h). Overall, this study shows the strength of the internal mechanism in ABFT that controls spawning traits. Spawning in ABFT is cyclical and highly synchronised on diel and annual scales. We consider that the timing of spawning is rather influenced by day length and its adaptive significance is discussed. [ABSTRACT FROM AUTHOR]

To identify spatio-temporal distribution in Namibian Cape hake (M. paradoxus and M. capensis), incidental hake catch by the horse mackerel fleet and targeted catch by the hake fleet were analysed for the period 1999–2004. The targeted catch, 45 955 fishing days, came from hake fishery logbooks and the incidental catch, 24 689 trawls, from observers'' sample data collected aboard vessels of the horse mackerel fleet. A strong negative relationship between monthly catch rates (cpue) and bycatch was observed, confirming that the seasonal change in catchability is caused by differences in hake vertical dispersion. The October trends were an exception: both cpue and bycatch were negative. A drop in catchability at different depths of the fishing grounds indicates that M. capensis migrates to shallower water (<200m) at the peak of spawning. Although there was no significant relationship between annual catch rates and bycatch, probably because of the short length of the time-series, annual bycatch should not be discarded as an indicator of hake recruitment. The results highlight the potential informative component of bycatch in identifying population patterns that cannot be extracted from the targeted catch. [Copyright &y& Elsevier]

The monthly and spatial patterns of chlorophyll concentration have been analysed for the northern Benguela upwelling system, which is characterised by its strong seasonality. Sea-viewing Wide Field-of-view Sensor data have been used to determine temporal patterns and to identify optimal conditions for chlorophyll production from October 1997 to October 2001. These data have been studied jointly with the sea surface temperature (SST) as an indicator of the physical variability in the region. The chlorophyll concentration did not present the strong seasonality of the physical environment but showed temporal and spatial optimal conditions. The highest chlorophyll concentration areas were found where and when the conditions of the water column were more stable. Although the time series is still too short to allow the designing of any conceptual model of the factors controlling the primary production of this region, it is long enough to permit us to conclude that it is not limited by the nutrient supply but by the stability of the water column. [Copyright &y& Elsevier]

This paper describes the use of multinomial logistic regression analysis to calculate the probability of strong, average or weak recruitment of Cape hake (Merluccius capensis). The model includes environmental indices, describing the extent of warm-water intrusion as well as the upwelling strength for different areas and periods over 2 years—from spawning until the fish are approximately 2 years of age. One of the warm-water indices as well as two of the upwelling indices have significant influences on the recruitment strength and these indices are included in the model. The rationale for using these indices is that if warm water is widespread during the spawning period (September–March) and the upwelling during the following May–September is reduced, the eggs spawned would be retained in favorable nursery areas which may result in potentially strong recruitment. If the upwelling during May–September of the following year produces sufficient food for the late juvenile hake, the chances of strong recruitment will be increased. The results indicate that the model accounts for 79% of the variance in recruitment. [Copyright &y& Elsevier]

Since 2014, the global land and sea surface temperature has scaled 0.23 °C above the decadal average (2009–2018). Reports indicate that Mediterranean Sea temperatures have been rising at faster rates than in the global ocean. Oceanographic time series of physical and biogeochemical data collected from an onboard and a multisensor mooring array in the northwestern Mediterranean Sea (Blanes submarine canyon, Balearic Sea) during 2009–2018 revealed an abrupt temperature rising since 2014, in line with regional and global warming. Since 2014, the oligotrophic conditions of the water column have intensified, with temperature increasing 0.61 °C on the surface and 0.47 °C in the whole water column in continental shelf waters. Water transparency has increased due to a decrease in turbidity anomaly of −0.1 FTU. Since 2013, inshore chlorophyll a concentration remained below the average (−0.15 mg·l−1) and silicates showed a declining trend. The mixed layer depth showed deepening in winter and remained steady in summer. The net surface heat fluxes did not show any trend linked to the local warming, probably due to the influence of incoming offshore waters produced by the interaction between the Northern Current and the submarine canyon. Present regional and global water heating pattern is increasing the stress of highly diverse coastal ecosystems at unprecedented levels, as reported by the literature. The strengthening of the oligotrophic conditions in the study area may also apply as a cautionary warning to similar coastal ecosystems around the world following the global warming trend. [ABSTRACT FROM AUTHOR]

This study represents the first nationwide assessment of marine recreational fishing catch compositions in Spain. Catch data from 7848 recreational fishers were collected using an online survey that was conducted from February 2016 to February 2017. The major modalities of the recreational fishing sector: shore fishing, boat fishing, and spearfishing were analysed independently in each Spanish coastal Autonomous Community (AC). The results revealed the high variability in the species compositions among modalities, as well as between the ACs, which showed spatial trends grouping them into larger regional units. For all three modalities, the Mediterranean and Atlantic AC were grouped separately. The Canary Islands were classified alone, except for the boat fishing modality, for which they were grouped with the Balearic Islands forming an archipelago group. Our results show the considerable heterogeneity in recreational fishing, and evidence for the need to study each modality as a separate compartment of a wider activity, and the risks of spatial extrapolations. [ABSTRACT FROM AUTHOR]

This study investigates the predation of P. noctiluca ephyrae on Atlantic Bluefin tuna (ABFT) eggs under different experimental conditions. The specific factors considered in the experimental design were: a) water mix conditions to explore predation under two-dimensional (2D) and three-dimensional (3D) prey distributions, b) prey density to investigate the ingestion rate capacity, and c) incubation time to inspect gut saturation. The eggs and jellyfish ephyrae were collected during the 2012 ABFT spawning survey off Ibiza (Balearic Isl., Western Mediterranean). The results showed that the proportion of feeding ephyrae increased with size. The mean clearance rate of feeding ephyrae, 4.14 L h-1, was the highest ever recorded for ephyrae. Under calm conditions the eggs floated at the surface (2D spatial arrangement) and the clearance rates, at low prey densities, were at least twice those under mixed conditions (3D spatial arrangement). At high prey density, clearance rate did not differ between mix conditions, probably due to the fast gut saturation, which was reached in c.a. 15 min, as revealed by time series observations of gut contents. The fast saturation of ephyrae and their slow digestion time of approximately 18 h suggest the existence of a diel feeding periodicity. We conclude that in the Western Mediterranean, P. noctiluca ephyrae are capable of predating on ABFT eggs, a highly pulsed and spatially restricted resource that potentially switches from a 3D to a 2D configuration in the absence of wind-generated turbulence. The P. noctiluca and Atlantic Bluefin tuna egg system might represent an example of a general mechanism linking pelagic and neustonic food webs. [ABSTRACT FROM AUTHOR]

This study analyzed the impact, added value and the social characteristic of the main Recreational Fishing (RF) modalities in two noteworthy Marine Protected Areas of Turkey, the sampling was carried out from December 2012 to March 2013. At each study site, Foça and Gökova MPAs, a fixed number of 130 fishers were randomly interviewed on fishers’ descriptors, fishing activity and associated costs. Descriptive indicators of recreational fishers by age and occupation were estimated by locations and fishing modalities. The results showed consistency between fishers ‘purchasing power and educational level and remarkable was the percentage of public servants among fishers, around 30%, with the exception of boat fishers in Foça (10%) where most were retirees (37.8%). A relevant percentage of fishers declared the sale of catch, maximum declared was in Foça boat fishers with a 96%. The results also were indicative that many of Foça boat fishers were retirees of the professional fishing sector but still commercializing their catch. As harvesting costs (5€/kg) were in most cases below the market value of the catch, the added value index of RF was negative. Furthermore, by selling the catch on the black market the RF fishers were creating illegal and unfair competition in the market with professional fishers. We conclude the RF in those areas cannot be classified exclusively as a leisure activity. We finally recommend the use of economic indicators such as RF index added value or harvest cost rather than absolute values in order better to understand the economics of RF. [ABSTRACT FROM AUTHOR]

• We performed the first comprehensive study on charter fishing in Turkey (Eastern Mediterranean). • It was estimated at 9246 charter trips hosting 138,690 charter fishers in 2017 in the Aegean coast of Turkey. • No differences were found between CPUE estimates from questionnaire and on-board surveys. • 38 species were found and Boops boops, Pagellus erythrinus and Diplodus vulgaris were the top three species influenced by charter fishing. • Results indicated the limited fishing policy knowledge of fishers and boat owners. This study attempts to improve the scientific knowledge of charter fishing on the Aegean coast of Turkey, where fishing activity and ecological indicators were investigated. Fishing and socio-economic data from both charter boat owners and charter fishers were collected using on-site questionnaires, and seasonal on-board surveys during 2017. No differences were observed between CPUE estimates from the questionnaire and the on-board surveys. The highest and lowest fishing activity were found in autumn and summer respectively. Charter owners reported conflicts with both private boat owners as well as commercial fishers. The annual activity was estimated to be 9246 charter trips hosting 138,690 charter fishers, who caught 277−305 tonnes. The total annual fisher and boat owner expenditure was estimated at €3.5 million and €0.6 million respectively. A total of 38 species were identified; most of the catch was represented by sparids, of which there were several species, such as Diplodus vulgaris , Sparus aurata , and Pagellus erythrinus, all of which were highly undersized. The results highlighted that the fishers and boat owners had limited knowledge of fishing policies. We conclude that managers should pay more attention to this activity and revise the existing regulations of charter fishing to improve fisheries management. [ABSTRACT FROM AUTHOR]