Coastal Fleet Research Articles

Length-Weight Relationships of 31 Fish and Invertebrate Species in the Northern Aegean Sea (Eastern Mediterranean Sea)

The purpose of this study was to examine the length-weight relationships (LWR) of fish and invertebrate species exploited by the small-scale coastal fleet in the northern Aegean Sea (eastern Mediterranean Sea). Length and weight measurements were collected during experimental trials carried out seasonally from April 2016 to February 2017. A total of 4358 individuals from 31 species (28 fishes, 2 crustaceans and 1 cephalopod) representing 21 families were collected. With the exception of brown comber (Serranus hepatus) and rough ray (Raja radula), all LWR slopes fall within the 2.5 to 3.5 range. The median b value for fishes was 3.11 and 50% of the b values ranged between 3.04 and 3.24. Somatic growth was isometric for 14 species, hyperallometric for 12 species, while only 5 species grew hypoallometrically. This is the first reference on LWR for sand sole (Pegusa lascaris) in the eastern Mediterranean Sea, while for snake blenny (Ophidion barbatum), common cuttlefish (Sepia officinalis) and deep-water rose shrimp (Parapenaeus longirostris) it is the first LWR in Greek waters.

Artificial upward trends in Greek marine landings: A case of presentist bias in European fisheries

According to the official landings as reported by the international databases for Greece, the declining trend of the Greek marine fisheries landings that had been continuous since the mid 1990s has been reversed during the last three years, with the total marine fisheries landings showing elevated values after 2016. We claim that this upward trend is an artifact that is attributed to the combined reporting of the landings of additional fleets since 2016 that had been separately reported before and resulted in 20–30% inflation of the landings. In 2016, the Greek statistical authorities included the landings of an extra fleet of 10,000 small-scale coastal vessels with engine horsepower lower than 20 HP together with the remaining coastal vessels, purse-seiners and trawlers whose landings formed the official reported Greek marine fisheries landings from 1970 to 2015. We acknowledge that this act of partial catch reconstruction improved the resolution of the landings and the officially reported values are now more realistic. However, the artificial, albeit inadvertent, inflation of the official Greek marine fisheries landings as they appear in international databases is a clear case of ‘presentist bias’ and may distort stock assessments and ecosystem modeling. As the currently misleading data stand, they are cause for substantial misinterpretation and analytical errors that can influence fisheries policy and have serious implications for fisheries management. We suggest that researchers should refrain from using the combined time-series and that a correction should be applied to the original time-series (1970–2015) to account for the entire coastal fleet.

Analysing the fisheries policy reform in the Faroe Islands: On the path to sustainability?

The home fishery in the Faroe Islands has since 1996 been managed predominantly with fishing days. The system has proven ineffective and has led to overfishing, fleet overcapacity, and low profitability in the home fishery. A process of reform began in 2007 when fishing licenses were terminated, effective from January 1, 2018. A fisheries policy reform was adopted by the Faroese Parliament in December 2017, just weeks before licenses expired. This paper describes the substantial fisheries policy reform and analyses its likely effectiveness and impact on the Faroese fishing industry. New measures include total allowable catch and individual transferable quotas for parts of the home fleet; allocation of fishing rights through auctions and development quotas; harvest fees; and the complete elimination of foreign ownership and capital. The fishing days system will remain in place for the coastal fleet. We identify a number of barriers for success, most notably that measures to ensure sustainability in the home fishery only apply to parts of the fleet, which may render them ineffective and hinder the much needed recovery of the important cod and haddock stocks in Faroese waters. Full implementation of the fisheries reform may be hindered by a lack of political consensus on a number of matters, and ultimately, full implementation depends on the outcome of the next general election in the Faroe Islands (2019), as the current opposition has made it clear it prefers the fishing days system.

Fatigue damage variation within a class of naval ships

Fatigue damage variation due to operating area differences is assessed using spectral fatigue analysis of ten naval vessels in a class. Four structural locations are considered. The fleet is divided into two groups: one based on the East Coast of Canada, operating primarily in the North Atlantic, the other on the West Coast of Canada, sailing mainly in the North Pacific. Unique operational profiles for each ship were developed from daily geographic locations, global seasonal wave statistics, and class-wide operating probabilities. Wave loads calculated with a frequency-domain seakeeping code were combined with linear finite element analysis to determine the corresponding stresses. Differences in fatigue damage estimates are small within each coastal fleet. The East Coast fleet experienced more severe wave conditions than their West Coast counterparts, resulting in East Coast ships having higher fatigue damage estimates. Also, fatigue damage estimates vary more in the East Coast fleet than in the West Coast fleet. Preferred speeds and headings in infrequent rough seas magnified the contributions of wave heights of 6.5 m and beyond to fatigue damage estimates.

Conflict and cooperation in an age structured fishery

The literature on ‘fish wars', where agents engage in non-cooperative exploitation of single fish stocks or interacting fish stocks is well established, but age and stage structured models do not seem to have been handled within this literature. In this paper we study a game where two agents, or fishing fleets, compete for the same fish stock, which is divided into two harvestable age classes. The situation modelled here may be representative for many fisheries, such as the Norwegian North Atlantic cod fishery where the coastal fleet targets old mature fish while the trawler fleet targets young mature fish. We analyze the game under different assumptions about the underlying information available to each fleet and the actions of the agents. The outcomes of the games are compared to the optimal cooperative solution. The paper provides several results, which differ in many respects from what are found in biomass models. The analysis is supported by numerical examples.

Analysis of occupational injuries in the sea fishing industry according to the type of fishery and the fishing activity.

Sea fishing is one of the most dangerous occupations. Numerous studies have already sought to evaluate the risk level of this occupation through the analysis of the frequency and seriousness of occupational injuries. The purpose of the present study is to analyse these accidents in terms of two main characteristics of the vessels involved: the fishery type (high seas, offshore, coastal, or inshore fishery) and the fishing activity (use of passive or active gears). Injury rates were calculated for the Brittany region and for the year 2012. A second analysis was carried out on 8,286 reported injuries that occurred in France from 2002 to 2012, while vessels were in the process of fishing. This first analysis shows that the incidence rate is very high (103 per 1,000 full-time equivalent fishermen) and that it depends more on the fishery type than on the fishing activity; the highest rates concern the offshore and the coastal fleets. Results of the second analysis show that the nature of accidents depends more on the fishing activity than on the type of fishery. These findings lead to a discussion of the causes of the highest incidence rate values and the causes of the observed variations. The discussion also involves the methodological difficulties related to the incidence rate calculations.

Bycatch of chondrichthyans in a coastal trawl fishery on Chubut province coast and adjacent waters, Argentina

Chondrichthyans are usually caught incidentally in fisheries for species of high commercial value and then discarded on board or landed as by-products. On the coast of Chubut province and adjacent waters (43°00′S–44°56′S) a bottom trawl fishery has developed targeted at the Patagonian shrimp (Pleoticus muelleri) and common hake (Merluccius hubbsi). Since 2005, this fishery has been monitored by the On-board Observers Program of Chubut province (POBCh). With the aim of advancing towards an ecosystem approach, POBCh not only collects information about target species but also about all the species caught by the trawl nets of the province fisheries. From the information collected by this programme it was possible to identify and record the chondrichthyan species vulnerable to the fishing gear used by the coastal fleet that operates from Puerto Rawson. The composition of the fleet catch was characterized according to the target species during the 2005–2014 period. In the analysis of 3786 hauls, 23 species of chondrichthyans (seven species of sharks, 15 species of batoids and a single species of Holocephali) were identified. Seven species showed a frequency of occurrence greater than 10% (Callorhinchus callorynchus, Discopyge tschudii, Mustelus schmitti, Sympterygia bonapartii, Psammobatis normani, Squalus acanthias and Zearaja chilensis). Species spatial distribution was evaluated and five areas of species assemblages were established. Besides the aspects related to bycatch, these analyses have contributed to the knowledge of the chondrichthyan biodiversity in the provincial coast where the fleet operates, a region with incomplete and mostly dispersed and outdated information.

The Use of Basketry in The Hulls of Vietnamese Seagoing Boats. The Status as of 2015 and The Question of The Future

Vietnam has a long tradition of building various sorts of boats for seagoing work that are either purely bamboo basketry, or a composite structure consisting of the bamboo basketry supported by greater or lesser amounts of wooden structure. Numerous authors have commented that these boats are more resistant to shipworm than wooden boats and that they are more flexible, better able to survive work in the surf zone. The extremely pragmatic Vietnamese water men simply use them because, for the investment, they best serve the need. These boats take many forms, some of which have spread to every corner of the country’s coastline (e.g., the round variety) and some which remain very local species, found only in the area where they have evolved. Many of them have a long history of development through decades or more, as rowing and sailing vessels, perhaps recently converted to engine power, while others seem to have been recently developed to fill local needs with a relatively inexpensive and durable boat. This paper is the result of 9 years of annual field expeditions of six weeks to two months each, during which the region’s boats were sought out and photographed. Thus, this is the first hand description of the “state of the fleet” as of 2015. It is the author’s expectation that the coastal fishing fleet in the region will undergo radical changes in the coming decades, as a result of legislation and regulation, in response to the availability of other boatbuilding materials and also from the consequences of depletion of both the fish stocks and the forests that have provided the need for boats and the boat building materials. The purpose of this work is to document the vessels in use today and during the past decade, and only secondarily to make any connection to the previous century(s) or imagine the future.

Emerging fisheries in subtropical coastal lagoons: Sphoeroides annulatus in Magdalena-Almejas Bay, BCS, Mexico (1998–2008)

Fishing is an important economic activity in Baja California Sur that creates thousands of jobs and provides high-quality food. Magdalena-Almejas Bay is a highly productive region that contributes an annual average close to 50% of state catches. It is the center of various small-scale fisheries that include the marine species commonly known as “finfish”, for which information is scarce. To understand the operation of this multi-species fishery and its recent changes, operations of the coastal fleet were analyzed using a historical series of official capture landing reports for the period 1998–2008. Surveys were administered to fishers in order to record their local knowledge on aspects such as target species, associated species and bycatch, fishing gear currently used, and fishing seasons and areas. Primary (on-beach) buyers were surveyed to document the market. The information obtained revealed the existence of emerging fisheries, highlighting Sphoeroides annulatus (locally known as “botete diana”) that ranks fifth in relative importance based on volume captured, production value, and number of capture landing reports. Fishing operations were documented on fishing trips with producers who use specific fishing gear locally called “chinchorro botetero” (puffer seine net). Due to the lack of published information about this particular fishery, this work attempts to set a foundation for the systematic documentation of this fishery, recording biological aspects of the species, fishing gear used, catch techniques, initial preservation, the prices of fish sold on the beach, the marketing channel, the target market, seasonality, and spatial distribution of the fishery.

Fishing in deep waters: The development of a deep-sea fishing coastal fleet in Norway

In the post-war political landscape in Norway, it has been a rooted consensus to maintain the coastal fleet as the largest and most important segment of the Norwegian fishing fleet. The simple and open technology, and low entrance costs in the coastal fisheries have secured employment in fisheries dependent districts, especially in Northern Norway. In order to protect the coastal fleet from the deep-sea fleet, the regime fixed the resource allocation and secured the coastal vessels with the largest share of the national TAC for cod. However, despite the strong institutionalization of the coastal fleet, the regime has not managed to avoid a rapid growth of deep-sea vessels and reallocation of quotas within the coastal group.

Survival and recovery of longline- and pot-caught cod (Gadus morhua) for use in capture-based aquaculture (CBA)

In capture-based aquaculture (CBA) wild cod (Gadus morhua) are caught and held in sea cages in order to supply fresh, high-quality fish throughout the year. CBA of cod is attracting growing interest among the Norwegian fishing industry. The most common gear for CBA is the demersal seine net (Danish or Scottish seine). However, there are powerful incentives to increase the extent of CBA, but this will necessitate the participation of fishing vessels from the smaller coastal fleet that utilise commercial pot and longline gear. CBA legislation is fish-welfare oriented and stringent, and documentation of stress, injuries and survival of captured fish is required for new capture methods. Field experiments were performed in order to determine the condition at capture of cod caught by longline and pots, using a combination of behavioural, physical, physiological and reflex-based indicators. Mortality and recovery were recorded in an onboard holding tank. No dead cod were observed at capture and, except for hooking wounds, the fish appeared unharmed. There was a high prevalence of fish that were incapable of submerging (about 40%), which if not dealt with resulted in high mortality (proportion: 0.79; 95% CI: 0.62–0.89). The mortality of fish that were capable of submerging was lower in pot-caught (0.09; 95% CI: 0.04–0.21) than longline-caught (0.39; 95% CI: 0.24–0.58) cod. Physiological and reflex stress measurements indicated that pot-caught cod suffered less stress from capture and handling, which suggests that pots are preferable as CBA gear. However, our knowledge of temporal and spatial variation in the suitability of fish for live storage (e.g. buoyancy status) is currently insufficient to predict the CBA potential of pots and longline outside of experimental conditions. Reflex impairment could predict mortality for pot and longline gears, and the inclusion of buoyancy status as part of a reflex/buoyancy impairment (RBI) score greatly improved model predictability. However, there was evidence that the relationship between RBI and mortality was influenced by the suite of stressors experienced by the fish, and this must be taken into careful consideration when comparing this relationship between fisheries.

Multi-Criteria Decision Analysis as a tool to extract fishing footprints and estimate fishing pressure: application to small scale coastal fisheries and implications for management in the context of the Maritime Spatial Planning Directive

In the context of the Maritime Spatial Planning Directive and with the intention of contributing to the implementation of a future maritime spatial plan, it was decided to analyze data from the small scale coastal fisheries sector of Greece and estimate the actual extent of its activities, which is largely unknown to date. To this end we identified the most influential components affecting coastal fishing: fishing capacity, bathymetry, distance from coast, Sea Surface Chlorophyll (Chl-a) concentration, legislation, marine traffic activity, trawlers and purse seiners fishing effort and no-take zones. By means of Multi-Criteria Decision Analysis (MCDA) conducted through a stepwise procedure, the potential fishing footprint with the corresponding fishing intensity was derived. The method provides an innovative and cost-effective way to assess the impact of the, notoriously hard to assess, coastal fleet. It was further considered how the inclusion of all relevant anthropogenic activities (besides fishing) could provide the background needed to plan future marine activities in the framework of Marine Spatial Planning (MSP) and form the basis for a more realistic management approach.

Fisheries management scenarios: trade‐offs between economic and biological objectives

AbstractAn age‐structured, population biology submodel and an economic submodel with vessel‐specific dynamics were applied to a demersal fishery in the North Aegean (NE Mediterranean) that consists of three main stocks: European hake Merluccius merluccius (L.), red mullet Mullus barbatus L. and striped red mullet Mullus surmuletus L. The Mefisto model is a bioeconomic simulation model through which the biological and economic submodels (disaggregated at the vessel level) are linked by means of a fishing mortality vector. Alternative management scenarios were built and tested based on input controls, and the performance of these strategies was examined against those of current policies. Three alternative management strategies were as follows: (1) reducing the coastal fisheries' fleet units; (2) limiting the effort level (days at sea) of the trawl fleets; and (3) changing the selectivity patterns of the trawl by increasing mesh size. The results show that for all three species, any of the three management measures (input controls) would be beneficial to both the stock and the fleets (over the medium and long terms) compared with the projections over time for the status quo. Improving the selectivity of the fishing gear proved to be more beneficial than limiting nominal effort, which was in turn more beneficial than decreasing coastal fleet size.

Spatial overlap of Black-browed albatrosses with longline and trawl fisheries in the Patagonian Shelf during the non-breeding season

Incidental mortality in fisheries is the main at-sea threat albatrosses are facing nowadays. In this study we used remote sensing techniques to model the degree of spatial overlapping between the Black-browed albatross (Thalassarche melanophris) and Argentine fisheries, assuming this as a proxy of risk for albatrosses. Eleven tags were deployed on albatrosses during the non-breeding seasons 2011 and 2012 in the Patagonian Shelf. Their distribution overlapped to different extents with the two coastal trawl, three offshore trawl and one demersal longline fisheries. The overlap index showed highest values with both coastal fleets, followed by the ice-chilling trawl fleet. These intersections were located in the Argentinean–Uruguayan Common Fishing Zone, in coastal areas of the SE of Buenos Aires province, El Rincón estuary and over the shelf break. The analysis of intersections of focal areas from albatrosses and all fisheries allowed the identification of thirty-four fishing management units (1° by 1° grid within the Argentine EEZ) classified as of medium, high or very high conservation priority. Very high priority units were placed between 35 and 38°S in the external mouth of Rio de la Plata, and between 45 and 47°S in neighboring waters East to the hake fishing closure. Although there were possible biases due to the limited number of tracked birds and the locations where albatrosses were captured and instrumented, the information presented in this study provides a comprehensive picture of important areas of overlapping during winter that could be used by the fishery administration to prioritize conservation actions under limited resource scenarios.

The influence of human rationality and behaviour on fish quality

This paper discusses the role of human rationality and behaviour with respect to perceptions of fish quality by exploring two intriguing observations of the sale of fresh cod and haddock from the Norwegian coastal fishing fleet to local fish buyers: (1) fish of poor quality is sold at too high a price and (2) catches from the coastal fleet based on long line/hooks, which provides the fish of the best quality, are in decline. These two phenomena are analysed by scrutinising the minimum price system, the power and dependency relationships between fishermen and fish buyers, the use of power by fishermen and fish buyers when negotiating prices and the transaction costs involved in evaluating fish quality. The results show that the first-hand sale of fresh cod and haddock suffers from several market imperfections, which help explain why fish of poor quality gains good prices and why coastal long lining is in decline. We argue that the behaviour of both fishermen and fish buyers represents “social dilemmas” where seemingly rational individual behaviours lead to a situation where everyone is worse off than they otherwise would have been. This article also discusses suggestions for solving these social dilemmas.

Back to square one? Fisheries allocation under pressure

In Norway there is a long tradition of allocating fish resources among the fishers. In modern times this has been done through specific allocation keys. This article describes the development of the allocation system for the offshore (trawler) and coastal fleets. The allocation system is closely related to stock assessment and the fixing of global quotas (TACs) as well as structural policies to prevent “capacity creep”. All three systems can be seen as institutions, where the TAC-machine is firmly established while the two others are under pressure, largely due to competition on the global fish market. The established goal of maintaining a diversified fishing fleet is now gradually being dismantled, with repercussions for coastal employment and settlement patterns. The coastal fleet is per 2013 something entirely different from the situation in 1990, when the coastal fisheries were effectively closed. Sooner or later this development is bound to change also the management institutions, and in particular the allocation system and the closely related structural policies.

Estimated bycatch of harbour porpoise (Phocoena phocoena) in two coastal gillnet fisheries in Norway, 2006–2008. Mitigation and implications for conservation

Using data collected during 2006–2008 from a monitored segment (18 vessels) of the Norwegian coastal fleet (vessels <15m) of gillnetters targeting monkfish and cod, we used general additive models (GAMs) to derive bycatch rates of harbour porpoise. These bycatch rates were then applied to fishery catch data on the target species to estimate the total number of porpoise taken by the coastal gillnet fisheries. The two best models estimated bycatches of 20,719 and 20,989 porpoises during 2006–2008, with CVs 36% and 27%, respectively. Thus, about 6900 harbour porpoises are taken annually in the coastal monkfish and cod gillnet fisheries. Although no abundance estimate is available for the coastal harbour porpoise population, this annual bycatch is likely not sustainable according to the management objectives defined by ASCOBANS. In the cod gillnet fishery, harbour porpoise bycatch rates decreased rapidly with increasing depth to 50m and then levelled off. In the monkfish gillnet fishery, bycatch rates decreased linearly with increasing depth throughout the depth range fished. To reduce harbour porpoise bycatches, we recommend that large mesh nets associated with the monkfish fishery to be prohibited at depths less than 50m. We also recommend to conduct experiments using Acoustic Deterrent Devices (ADDs or ‘pingers’) on nets set deeper than 50m. If these devices prove successful in reducing porpoise bycatch, we propose that ADDs should be implemented in the Norwegian coastal gillnet fisheries for cod and monkfish.

The importance of common sense: How Norwegian coastal fishermen deal with occupational risk

Abstract Due to a high number of fatalities and personal injuries, commercial fishing is considered a risky occupation. In the Norwegian context, work-related fatalities have been especially prominent in the coastal fleet. Despite high statistical risk, many fishermen claim they do not worry about their work being dangerous. Applying a qualitative approach, this article argues that shared beliefs and practices such as common sense, taking precautions, evaluating risk as well as relying on each other through cooperation on board and amongst vessels, can be understood as integrated or institutionalized ways of dealing with potential risk. These elements interact with the individual's personal experiences, and influence the fishermen's perceptions of the dangers at hand. The points presented here, may be a part of the reason why fishermen do not necessarily see the need for formal regulations aimed at improving their safety.

The diet of Olrog's Gull (Larus atlanticus) reveals an association with fisheries during the non-breeding season

In this study, we used stable-isotope analysis to determine the importance of different food resources in the diet of an endemic gull species of the Atlantic coast of southern South America during the non-breeding period. We compared the isotopes 15N and 13C in the blood of Olrog's Gulls (Larus atlanticus) of different ages with those in potential prey of the Gulls. We also determined the abundance of Olrog's Gull in their wintering areas and attending coastal fisheries operations in a small region of Argentina. An isotope-mixing model showed differences in the isotopic signatures of adult, subadult and juvenile Gulls. Although the isotope-mixing model showed crabs as the main prey, it also showed that demersal and pelagic fish may be important in the diet. We speculate that the demersal and pelagic fish in the diet, shown by their isotopic signatures in the Gulls, may be taken in association with coastal fisheries, particularly bottom otter-paired trawling. At-sea observations showed that Olrog's Gulls were one of the most-common birds attending fishing operations of the Argentine coastal fishing fleet, taking advantage of fish mostly made available through hauling operations.

Injuries in the commercial fishing fleet of Norway 2000–2011

A working fishing vessel at sea is an elaborate collection of interacting accident potentials, barely controlled. Even the deck underfoot betrays the unwary, as can every other aspect of the normal daily grind onboard, as fishers ply their trade in weather foul and fair. All elements of the vessel at sea conspire in making this the most dangerous and difficult of all professional callings, an inexplicable calling where life and limb are continually at risk.This article is based on an examination of reported occupational injuries from the Norwegian fishing fleet from 2000 to 2011. The aim is the determination of important characteristics and traits in the statistics, which may be used to focus and further preventative measures to be applied within this fleet. The results indicate that the current intervention programs and improvement measures have to date made a significant impact on injury levels within the fleet. This study has borne witness to a reduction in injury numbers and incident rates year on year for the past 12 years. It identifies the trawler fleet as the seat of the highest incident rates of injury occurrence, while the small coastal fleet had the lowest reported numbers of injuries. Under-reporting of minor injuries is revealed as a problem in the current reporting system of fisher injuries while the manner, location and body regions of reported injuries are also investigated. These findings lead to a discussion on the future requirements for the Norwegian fleet for further injury reduction and improved reporting practices.