Inshore Fisheries Research Articles

Ultimate Fighting Crab: Agonistic Behaviour, Dominance, and Recognition in the Edible Crab, Cancer pagurus (L.)

Edible crabs (Cancer pagurus) are an economically important species for Scottish inshore fisheries, with an estimated annual landing value of GBP 16 million (2023). Research into the behaviour, particularly agonistic behaviour, of this species is currently lacking. This paper aims to investigate behaviour, social interactions, potential hierarchies, and the impact of claw size on the outcomes of agonistic interactions of male C. pagurus through behavioural trials and retrials. Crabs were semi-randomly assigned to pairs (based on allocated condition index rating) and introduced to one another in trial tanks. Each pair underwent two trials, 24 h apart (the “trial” and “retrial”). Analyses of video records of agonistic bouts revealed that 77% of retrials were won by the initial victors, with a significant decrease in fight time between trials and retrials. Fight time was not correlated with weapon size (claw length, height, and depth). There were no differences in weapon size of winners and losers of bouts. Winners exhibited a significantly higher frequency of aggressive and dominant behaviours (approach, aggressive contact, threat displays, and mounting), and losers exhibited higher frequencies of submissive behaviours (withdrawal, retracting limbs, and remaining motionless). These results suggest that individual behaviour may play more of a role in dominance than size or other morphometric characteristics.

Integrated Genetic and Statolith Shape Analysis Reveals the Population Structure of Loliolus (Nipponololigo) uyii (Cephalopoda: Loliginidae) in the Coastal Waters of China

Understanding population structure is a priority for evaluating population dynamics of commercially fished cephalopods under fishing pressure and environmental changes. This study employed a multidisciplinary approach to clarify the population structure of Loliolus (Nipponololigo) uyii, a common squid in inshore fisheries. Sampling was conducted multiple times to cover the distribution range across the East China Sea and South China Sea. High haplotype diversity was revealed by three gene markers (COI, 16S and ODH). Two geographical clades with significant genetic differentiation were divided through phylogenetic trees and haplotype networks. The boundary between the two clades is delineated by the Dongshan population in the southern East China Sea. Furthermore, the neutrality tests and mismatch analysis suggested that L. (N.) uyii populations may have undergone population expansion. Correspondingly, statolith differences in lateral dome and posterior indentation, along with high classification success, further supported the genetic division. The overall difference in statolith shape also efficiently identified seasonal groups in the Beibu Gulf lacking genetic differentiation. This result offers new insights into the influence of genetic and environmental factors on statolith shape. The integrated results provide a comprehensive understanding of the population structure of L. (N.) uyii, laying the foundation for resource development and the conservation of the species.

Inshore Fisheries and Conservation Authorities: Fisheries regulator or environmental backstop? The complexities of section 153 Marine & Coastal Access Act 2009

Since the introduction of the Marine and Coastal Access Act 2009 (‘MCAA'), fishing within England's inshore marine area has been managed by Inshore Fisheries and Conservation Authorities (IFCAs). The powers and duties of IFCAs are contained in section 153 of MCAA and include a conservation remit; requiring IFCAs to have regard to the sustainability of fisheries activities and to conservation of the inshore marine environment. The inclusion of conservation in the name of these bodies and references to sustainability in their duties leads to questions as to the scope of IFCAs’ remit in relation to conservation. An examination of the parameters of section 153 suggests that the conservation that IFCAs can concern themselves with must relate to the management of fisheries activities, although the precise extent of this duty is not always clear. At the same time, examples from recent IFCA experiences, suggest that some stakeholders are interpreting the conservation duty much wider and viewing IFCAs as a broad conservation authority for the inshore marine area, thereby placing increased pressure on the organisations. The tension this mismatch creates must be carefully navigated by IFCAs if they are to remain within the bounds of the powers given to them by MCAA.

Evaluation of ecological health of Hainan Island inshore waters in the South China Sea based on preliminary fish biotic integrity index (Actinopterygii and Elasmobranchii)

The well-being of marine ecosystems significantly influences biodiversity and ecological equilibrium amidst pressing challenges such as overfishing, water pollution, and climate change. Drawing upon data from two fishery stock surveys conducted in the inshore waters of Hainan Island in 2022, this study undertook a comprehensive evaluation of the marine ecosystem’s health status in the region. Employing the Fish Index of Biological Integrity (F-IBI) analysis method, coupled with an examination of the structural and functional aspects of the fish community, our research sheds light on the prevailing conditions. Our study revealed a spatial dichotomy within the fish communities of the study area and delineated them into two distinct groups: the northwestern and southeastern ones, with evident disparities in community structure between the two. By employing indicator screening and calculation, we segmented the fish health index in the inshore waters of Hainan Island into five tiers. Despite discernible anthropogenic influences, the ecological health of these waters remained generally robust. Notably, the mean F-IBI of fall (56.30) significantly exceeded that of spring (48.16) (P < 0.01). Furthermore, regarding spatial distribution, the ecological well-being of the southeastern waters surpassed that of the northwestern and Qionghzhou Strait waters. This study represents a pioneer endeavor to apply ecological health assessment methodologies towards informing resource management and conservation strategies for the inshore fisheries of Hainan Island. By furnishing a scientific foundation, our research contributes to the pursuit of sustainable marine ecological development within this locale.

First evidences in the Gulf of Cádiz (northeastern Atlantic Ocean) as a spawning area of bullet tuna species (Auxis rochei)

The bullet tuna, Auxis rochei, is a commercially significant scombrid in small-scale inshore fisheries in the northeastern Atlantic and western Mediterranean. We hypothesized that the Gulf of Cádiz could serve as a spawning area of bullet tuna. We analysed the gonads and GSI of 428 individuals (23.9–48.7 cm SFL) caught by Portuguese and Spanish traps along the south Atlantic Iberian Peninsula, as well as by Spanish recreational fishery between 2004 and 2021. Larvae of bullet tuna were collected during surveys conducted on the northern shelf of the Gulf of Cádiz in June and August. Bullet tuna landings exhibited high seasonality in the Gulf of Cádiz, peaking during the warmest months, notably from August to October. Analysis of maturity data, monthly GSI variations, larvae distribution, and landings indicate that bullet tuna is reproductively active in the Gulf of Cádiz, particularly in July and August. A more comprehensive understanding of the reproductive behaviour of bullet tuna in this region is essential to confirm its reproductive success and to study recruitment mechanisms further.

Trawling through time: reconstructing a late nineteenth century beam trawl for scientific inshore fishery investigations

Understanding long-term change in fish populations often relies on comparing catches from historical and contemporary trawl surveys. However, such comparisons may not resolve biases associated with differences in fishing gears and their relative catchabilities. It is possible to reduce these uncertainties by replicating historical trawl gear and practices. With the availability of unique historical catch data, we investigated the trawl gear employed by the Northumberland Sea Fisheries Committee (NSFC) during scientific surveys conducted between 1892–1913 in inshore waters of the Northumberland coast (UK), and describe our attempt to reconstruct the gear using currently available materials. We reviewed the historical literature, photographs and acquired technical expertise to reconstruct a late nineteenth century beam trawl used by the NSFC. The replica gear consisted of a 6.7 m beam connected by two Brixham style wrought-iron trawl heads, which held open a triangular-shaped trawl net with rounded ground-rope. Following construction, we tested the performance and catchability of the replica gear by conducting comparative trawls using a modern otter trawl in August 2018 and March 2019. Both trawl gears exhibited similar catches for flatfish in August trials, yet a higher proportion of individuals were landed by the otter trawl in March. Zero or negligible catches were exhibited by the replica gear during this period. This work collates relevant information to describe the evolution, design and functioning of late nineteenth century beam trawls used around the British Isles, providing an important repository for investigators interested in trawl technology and survey designs.

Donald J. Feltmate, Building a Better Boat: How the Cape Island Longliner Saved Nova Scotia’s Inshore Fishery by Harry T. Holman

Donald J. Feltmate, Building a Better Boat: How the Cape Island Longliner Saved Nova Scotia’s Inshore Fishery by Harry T. Holman

Taking forward perceptions of identity: the Sea League’s campaign to protect maritime communities and the environment.

The Sea League was a significant but relatively short-lived movement of popular protest (1933-1939), active in the communities of the Outer Hebrides for the purpose of drawing the attention of government to deep concerns over island social and economic circumstances. Founded in the Island of Barra, their cause was political and public recognition of the destruction of inshore fisheries and of consequent loss of livelihoods in island communities. Through its campaign, evidenced through its newsletter and surviving correspondence, the Sea League can be seen as propagating perceptions of identity in fishing communities in the Outer Hebrides based on commonality of interests and the threats to them from a wider society. This gave their cause profile although the wider aims were only partially realised in the nearly six years of campaigning which was effectively ended by the outbreak of the Second World War. Perceptions of identity engendered by the Sea league have continued to be shaped by the culture and language of the Gàidhealtachd, and these same communities in which the language survives are engaging with the contemporary climate-crisis and current debates on environmental conservation. Considerable space is given to this to highlight the relevance of the Sea League’s campaign for the part of ‘human ecology’ in the marine environment.

Low trophic redundancy among temperate wrasse species implies ecosystem risks associated with a multi-species inshore fishery

Low trophic redundancy among temperate wrasse species implies ecosystem risks associated with a multi-species inshore fishery

Factors influencing risk perception of inshore and offshore artisanal fishers in a marine protected area in Brazil

AbstractArtisanal small‐scale fisheries are crucial for subsistence and food security, especially in developing countries. However, artisanal fishers face stressors, such as economic and social marginalization, conflicts, and overfishing. Socio‐economic attributes potentially influence their risk perception. We investigated risk perception among artisanal fishers in a Marine Protected Area through interviews and semi‐structured questionnaires. Risk perception was positively influenced by fishing environment and negatively influenced by a lack of religious beliefs. Offshore fishers faced more operating conditions and time at sea, with higher risk of losses, and perceived more health and conflict risks. Inshore fishers have higher perception of environmental degradation. Prioritizing different risk perceptions is essential for effective fisheries management. Separate management plans for offshore and inshore fisheries are recommended due to varying catch, environmental perception, socio‐environmental risks, and exploited resource characteristics among artisanal fisher groups.

Competitiveness Index and Type of Offershore and Inshore Fishery by Region

Competitiveness Index and Type of Offershore and Inshore Fishery by Region

An evaluation of Oman’s National Fisheries Development Strategy (NFDS) 2013–2020: Wealth or welfare maximisation?

This paper evaluates Oman’s National Fisheries Development Strategy 2013–2020 (NFDS) which was adopted in 2012 to guide the future development of the country’s fisheries sector. The NFDS is an ambiguous document which gives rise to two different interpretations. First, it can be interpreted as a radical model of fisheries development which is driven by the principle of wealth-maximisation and entails a massive expansion and modernization of the fishing industry, transforming it from its traditional artisanal inshore form into a high-tech industrial form with an emphasis on a large new offshore sector. Alternatively, it can be interpreted as a traditional artisanal inshore fishery model which is driven by the principle of welfare-maximisation upholding the long-established cultural values of fisheries-dependent communities. The paper discusses these two different interpretations of the NFDS, drawing on the literature as well as the insights of 176 respondents obtained from 44 key informant interviews, 10 focus group discussions, and 92 survey questionnaires. The findings are that the government has settled for a hybrid model consisting of a diluted version of the radical vision - encouraging the development of a moderately sized offshore sector - while continuing to strongly support the traditional artisanal sector. Judging by the fourfold increase in fisheries production in Oman since 2012, this hybrid model seems to be successful in expanding the size of the sector. The wider lesson to be drawn from this study is the importance of balancing economic benefits of modernisation with social benefits of traditional communities – a balance that many other countries (both developing and developed) are struggling to strike.

Offshore aquaculture in China

AbstractThe mariculture industry is planning to move offshore due to the decline of China's inshore fishery resources, the deterioration of the water environment, inefficient industrial structure and other influencing factors. This article first analyses the imbalance between supply and demand of aquatic products, the development space of offshore aquaculture and the supporting policies, thereby concluding that China has significant potential to develop offshore aquaculture. Subsequently, the development status of offshore aquaculture in China is examined. The research progress of China's offshore aquaculture facilities, marine hydrology, environmental carrying capacity, aquaculture technology and the status of aquaculture operation equipment are also summarized. Furthermore, the problems existing in the development of offshore aquaculture are pointed out. On this basis, future development ideas for China's offshore aquaculture can be planned in terms of sea area layout, optimized and improved seed production systems, and research and development of offshore aquaculture technology and pellet feed. The relationship between the development of offshore aquaculture and ecological protection should be coordinated. Additionally, an energy security system can be built based on clean energy, and the development of related industries can be driven through the complementary industrial division of labour. The present work aims to provide a reference for promoting the development of offshore aquaculture in China.

Participatory-based bio-economic activity mapping of small-scale fisheries: towards holistic management in the Bay of Biscay

Abstract The main goal of this paper is to improve the understanding of the spatial distribution of small-scale inshore fisheries (SSF) in coastal waters of the Bay of Biscay. The study used a participatory process, in which fishers, regional administration, and researchers were involved in supplying the data. Displayed on a 1-km2 grid, the data for effort and catch composition, variable costs, revenue, and profits at each site show the spatial patterns of the main SSF metier activities. This information indicates the economic value of the fishing grounds and the cost of reaching those areas, which can reveal possible trade-offs for more distant fishing grounds. Trammelnet vessels are widely dispersed, following economic incentives, while longliners also demonstrate high mobility, using many fishing sites, though the economic incentive does not always lead to high benefits. A narrow expansion range with activity close to the coastal area (trap, gillnet, and trammelnet users) suggests that the target-species stocks maintain their economic profitability even though it is lower than that in other coastal fleets. Such information helps develop a holistic approach to SSF management in this multi-use region by increasing the availability of high-quality multidisciplinary geospatial data, currently in short supply for this fleet.

Integration or separation? The future of the English small-scale coastal fishery

The decline of inshore or small-scale coastal fisheries (SSCF) in many countries across the world has been well-documented in major studies published during the last 10 years. Researchers report decreasing stocks of marketable fish, inadequate fish quota allocations, and virtual exclusion from fisheries management decision-making bodies. The situation in England is a case in point, where many SSCF are subject to these pressures to the point that their livelihoods are threatened. A recent initiative sponsored by an industry agency to safeguard the position of the inshore sector aims to protect SSCF in England from decline and possible extinction by integrating it into the mainstream fishing industry and ensuring its representation on a proposed co-management body which would share decision-making between industry and government. However, drawing on the literature, archival documents, newspaper articles, and personal communications, we conclude that integrating all parts of the fleet together and setting up shared co-management arrangements is not a guarantee of SSCF survival because integration would tie SSCF down to the agenda of the large-scale fisheries (LSF) sector with no certainty that the special needs of SSCF would be met if they conflicted with the interests of LSF. Instead, our findings lead us to recommend forging a separatist path for SSCF, recognising its distinctive identity as an inshore fishery closely connected with coastal communities. We propose, therefore, two independent fisheries each with its own mode of management: SSCF governed by a regime of community quotas and exclusive spatial access to inshore waters; and LSF governed by a regime of individual transferable quotas (ITQs).

Democracy and Human Rights in the Management of Small-Scale Fisheries in England

Small-scale fisheries (SSF) in England face several challenges to their viability. We argue that the source of these challenges can be traced to the more dominant large-scale fisheries (LSF) sector which has more influence than SSF over government policies. A recent attempt to mitigate the impact of these challenges has been made by the Future of Inshore Fisheries initiative whose main prescription is co-management, i.e., giving SSF a participatory role with the government and LSF in the decision-making in English fisheries management. Co-management is a form of democracy and it may help the SSF to deal with their problems. However, in our view, the English SSF also require an acknowledgement of their human rights to a fair quota and protected access to productive inshore waters. In making this case, we draw on normative arguments to assert that human rights are prior to democratic processes. Our conclusion is that both democratic decision-making and human rights principles are needed to secure the English SSF from the real threat of extinction.

Improving size selection in the Norwegian red king crab (Paralithodes camtschaticus) fishery through modification to pot design and soak time.

Red king crab (Paralithodes camtschaticus) represent a valuable inshore fisheries resource for communities in northern Norway. The fishery is regulated east of the 26th meridian by vessel quotas and a minimum landing size of 130 mm carapace length. It is executed using baited pots that must be fitted with circular escape openings. Despite this, pot catches typically contain a large proportion of sub-legal sized crab. This implies increased labor-intensive sorting which can lead to crab becoming injured, loosing limbs or delayed mortality. Such consequences negatively impact the sustainability of the fishery. In this study, we examined the potential of two new pot designs and longer soak times to reduce undersized crab catches in comparative field trials. A design consisting of a tarpaulin panel on the pot entrance (intended to prevent undersized individuals from gaining traction and entering) was found to be no better at reducing undersized catches than the currently used commercial design fitted with escape openings. A second design with a baited lower chamber (which could be accessed through the pot floor via escape openings) was intended to motivate undersized crab to escape more readily. If fished commercially, any crab in the bottomless lower chamber would be left behind on the seabed upon hauling. This design was found to have minimal effects on sublegal catches. However, increasing the soak time of the currently used commercial design from 1 day to 4 days reduced undersized crab catches substantially. This effect is likely related to bait becoming exhausted over time, thereby increasing the opportunity and motivation of sublegal crab to find and exit the pot through the mandatory escape openings. Laboratory-based behavioural observations using the panel design indicated that entry was dependent on crab orientation and that crab were less successful at entering than for the commercial design. However, all sizes of crab used an unintentional fold in the panel to increase their entrance probability. This may explain the lack of success of this design during the field trials. We conclude that ensuring bait is exhausted by employing longer soak times than is typically used by fishers would reduce catches of undersized crab in the fishery. Data availability statementThe data underlying this article will be shared on reasonable request to the corresponding author.

Vulnerabilities of northern Peruvian small-scale fishing communities revealed by the COVID-19 pandemic

During periods of abrupt change, understanding sources of resilience for adaptability in small-scale fisheries (SSF) is important for enhancing their sustainability. This study aimed to understand the vulnerability of five diverse SSF communities in northern Peru amid COVID-19, by analyzing key sensitivity indicators that influence their response to the immediate impacts caused by the lockdown and their short-term adaptive capacity. We established a baseline for each fishing community, through socio-economic, fishery-related, and commercialization characteristics. We then assessed fishery changes before and during the first and most restricted lockdown and community responses to the pandemic impact. These were used to generate a score value that ranked the adaptive capacity of each community. Through a regression tree we identified key SI that most influence the communities´ response to COVID-19 impacts. Our results show that the ‘fishing area related to distance from the coast’ was the most important sensitivity indicator as offshore fisheries were riskier (i.e. higher travel costs) than inshore fisheries. The communities that responded better to COVID-19 impacts had high social capital (i.e. self-organization and social learning); while, the least successful communities responded passively. The adaptive strategies of SSF here identified included diversification of fishing activities (i.e., shifting to fishery areas closer to the coast), selling marine products at local markets, fishing fewer days, establishing agreements with authorities, using technology (i.e., digital platforms) in creative ways to enhance local seafood value chains, and combining different types of knowledge from different actors. These strategies fostered the re-organization of the supply chain in which a shift to local markets became a trend. We include a list of recommendations for decision-makers and principal insights related to community resilience.

Population genomics reveals a single semi-continuous population of a commercially exploited marine gastropod

Buccinum undatum is a commercially important marine gastropod with limited dispersal capabilities. Previous genetic studies utilising microsatellites and Double-digest Restriction-site Associated DNA sequencing (ddRADseq) provided evidence that B. undatum exhibits fine-scale genetic structure. Using ddRADseq, 128 individuals from the southern North Sea, English Channel, and the Irish Sea were genotyped using 7015 filtered single nucleotide polymorphisms (SNPs), 19 of which were identified as being under putative selection. Multiple genetic clustering methods – Discriminant analysis of principal components, Principal component analysis, and Sparse non-negative matrix factorisation,– were used to investigate population structure. Spatially explicit genetic structure was investigated using an Estimated Effective Migration Surface analysis and a Mantel correlogram. A single genetic population was found using neutral SNPs, with weak within-population structuring. Global FST was low (0.0046, p < 0.001), and pairwise FST estimates between sampling locations were between 0.0004 and 0.0224. There was a significant trend of isolation-by-distance across all sampling locations (r = 0.743, p < 0.001). Positive spatial autocorrelation indicated whelks located ≤ 50 km of one another were significantly more related than by chance (r = 0.12, p = 0.003), further emphasising the low dispersal capabilities of B. undatum. Finally, two barriers of lower-than-average dispersal were discovered; the Thames estuary and across the English Channel. Management implications are discussed for the sustainability of whelks from inshore fisheries.

Climate impacts alter fisheries productivity and turnover on coral reefs

Alteration of benthic reef habitat after coral bleaching and mortality induces changes in fish assemblages, with implications for fisheries. Our understanding of climate impacts to coral reef fisheries is largely based on fish abundance and biomass. The rates at which biomass is produced and replenished (productivity and turnover) are also important to sustaining fisheries, yet the responses of these metrics following bleaching are largely unknown. Here, we examine changes in fish productivity and turnover after mass coral bleaching events in Seychelles, on reefs that were recovering to coral-dominated habitats and those that shifted to macroalgae-dominated regimes. Productivity of fish assemblages increased on all recovering reefs, particularly on fished reefs resulting in levels similar to protected reefs 19 years after bleaching. Herbivore-detritivores, such as scraping and excavating parrotfish, appeared to drive biomass production through increased abundance on recovering reefs. Productivity on regime-shifted reefs remained stable at 1994 levels in fished areas, with increases observed on protected reefs. Large increases in browser productivity (particularly on protected reefs), combined with increases for invertivores, maintained post-bleaching productivity on macroalgal reefs. For all diet groups, net turnover was generally higher on fished regime-shifted reefs than on recovering reefs, suggesting fish biomass is more readily replenished on macroalgal reefs. Reef structural complexity was a positive predictor of productivity for all diet groups. These findings indicate that post-bleaching reef fish productivity is strongly influenced by benthic recovery trajectories, and demonstrates the importance of herbivore and invertivore species in sustaining small-scale inshore fisheries following climatic disturbances.