Larger Boats Research Articles

Anchoring pressure and the effectiveness of new management measures quantified using AIS data and a mobile application

Large boats can have a major impact on sensitive marine habitats like seagrass meadows when anchoring. The anchoring preference of large boats and their impacts can be mapped using Automatic Identification System (AIS). We found a constant increase in the number of anchoring events with, until recently, a large part of them within the protected Posidonia oceanica seagrass meadows. French authorities adopted a new regulation in 2019 forbidding any anchoring within P. oceanica seagrass meadows for boats larger than 24 m. The number of large ships (>24 m) anchoring in P. oceanica meadows significantly decreased after the enforcement of the regulation. The surface of avoided impact thanks to the new regulation corresponds to 134 to 217 tons of carbon sequestered by the preserved meadow in 2022. This work illustrates that a strict regulation of anchoring, based on accurate habitat maps, is effective in protecting seagrass meadows.

Economic loss as the impact of climate change on tuna fishermen in Northern Indonesian waters

This study aims to determine how big the impact of climate change is on the economic loss of the catch of Tuna fishermen in the northern waters of Aceh Province, Indonesia. Unfavorable climate change has an impact on decreasing fishing catches due to changes in seawater biophysics such as increasing sea surface temperatures, increasing wave height, and wind. The respondents in this study were 40 Tuna fishermen, located in 6 (six) villages in the waters of North Aceh., from two different WPPs, namely WPP 571 and 572. Data were collected by interview and using questionnaires. The results of this study indicate that there is a decrease in the level of welfare of coastal communities which is marked by a decrease in income levels caused by climate change. The results of the Present Value calculation also show that there is an economic loss for both small boats (<5GT) and large boats (>5GT), and the slope loss for small fishermen is steeper than for large fishermen. This indicates that large fishermen are more resilient to climate change than small fishermen. For an adaptation strategy, it is recommended that Tuna fishermen on the north coast of Aceh waters, both those in WPP 571 and 572, leave small boats and switch to larger boats (>5GT) which are proven to be more resistant to climate change than small boats (<5GT).

Promoting fishing profession and general well-being: A call for labour policy

Fishing is a longstanding occupation in the world. Small-scale fishing (SSF) communities of South Asia face many challenges in their lives and livelihoods. This study was conducted in one Jaladas village of southeastern Bangladesh to determine the conditions of fishing labours in big boats and provide some evidence-based recommendations for enhancing their holistic well-being. This study adopted the qualitative research design, specifically the Focus Group Discussion (FGD). A random survey of 50 households was conducted to find out socio-economic conditions. This paper finds that the young Jaladas are pushed away from their birth-ascribed occupation and engaged as fishing labours in big boats. Their existing working environment is like an ancient slavery system. Fishing labours are bound to work under such adversative conditions for survival. SSF communities become poorest of the poor due to lake of sufficient concentration from the government, NGOs, private sector, international development agencies and other actors. Moreover, relevant articles of the Universal Declaration on Human Rights (UDHR) and FAO initiated SSF Guidelines are not implemented properly in support of fishing labours working in large boats. Highest profit-earning mentality of commercial entrepreneurs, apathy, absence of rules of law; and non-recognition the rights of labours under small-scale fisheries sector in Labour Law of Bangladesh are major reasons for plights of fishing labours. Still research works are very inadequate in this area. Therefore, global human rights organizations are in dark from real scenario. This paper urged that the Government of Bangladesh (GoB) should include prioritized needs of fishing labour as provisions during the amendment of Labour Law. Proper execution of Labour Law and establishing the rules of law are concerning issues for ensuring the well-being of fishing labours.

Fuel use intensity of hilsa fisheries in the lower Meghna river estuary of Bangladesh

Among the species caught by small-scale fisheries in Bangladesh, hilsa (Tenualosa ilisha) is the most important by volume and of great cultural importance. Hilsa fishing boats have over the last decade been mechanized, enabling longer trips and larger hauls. This development has, however, also resulted in increased fishing pressure and increased reliance on fossil fuels. This study estimates the fuel use intensity (FUI) of hilsa fishing, calculated as fuel per unit landed mass of hilsa at one of the main landing stations (Chairman ghat) in the coastal area of Noakhali district, Bangladesh. Primary data were collected from three types of artisanal fishing boats commonly used in hilsa fisheries, namely small boats (Choto/Khosa tempo), medium boats (Tempo), and large boats. Our results show a higher fuel use intensity in small boats (750 ± 468 l t-1), compared to medium (495 ± 270 l t-1) and large boats (576 ± 365 l t-1). Considering the gross catch and total fuel consumption of all boats, the absolute FUI is estimated at 463 l t-1. Thus, the FUI of hilsa fishing is slightly lower than the average for global fisheries FUI (489 l t-1). In terms of greenhouse gas (GHG), not including other lifecycle inputs (e.g. infrastructure, ice, supply chain etc.) than fuel (i.e. diesel, LPG, and wood), the average global warming impact is 1.72 ± 0.34 tonnes CO2-eq. t-1 overall catch. This study provides a baseline estimate for FUI and GHG emissions from contemporary hilsa fishing, and proposes solutions for addressing environmental issues and improving the overall performance of the sector.

Big fish in thin markets: Competing with the middlemen to increase market access in the Amazon

Middlemen are ubiquitous in supply chains. In developing countries they help bring products from remote communities to end markets but may exert strong market power. We study a cooperative intervention which organizes together poor fishing communities in the Amazon — one of the poorest and most remote regions of the world — to purchase large boats in order to partially bypass middlemen and deliver their fish directly to market. We find that the intervention increases income by 27%, largely through an increase in price received, and also increases consumption. Moreover, the intervention is highly cost effective with the projected stream of income gains easily covering the cost of the investment. Finally, we formalize a model in which the market power of middlemen itself can create a poverty trap, which can be eliminated with cooperative investment.

Atmospheric Contamination of Coastal Cities by the Exhaust Emissions of Docked Marine Vessels: The Case of Tromsø

Docked ships are a source of contamination for the city while they keep their engine working. Plume emissions from large boats can carry a number of pollutants to nearby cities causing a detrimental effect on the life quality and health of local citizens and ecosystems. A computational fluid dynamics model of the harbour area of Tromsø has been built in order to model the deposition of CO2 gas emitted by docked vessels within the city. The ground level distribution of the emitted gas has been obtained and the influence of the wind speed and direction, vessel chimney height, ambient temperature and exhaust gas temperature have been studied. The deposition range is found to be the largest when the wind speed is low. At high wind speeds, the deposition of pollutants along the wind direction is enhanced and spots of high pollutant concentration can be created. The simulation model is intended for the detailed study of the contamination in cities near the coast or an industrial pollutant source of any type of gas pollutant and can easily be extended for the study of particulate matter.

Boat hull assembly methods and provision manufacturability of their designs

The design and technological characteristics of modern boats are presented and the technology of block assembly of hulls of large boats, as well as of frame assembly of hulls of small boats, is described. The design and the principle of operation of the equipment used, such as slipway-conductors and readjust able beds, providing the possibility of assembling the hulls of small boats from pre-made modules of the outer skin, representing its development in the plane, are considered. Particular attention is paid to the structural and technological improvement of boat hulls, aimed at replacing welded stiffeners with stamped corrugations and assembly welded joints of the outer skin — mechanical joints on pressed elements made of aluminum alloys. In accordance with the requirements for ensuring quality and reliability of the assembly of boats hulls, as well as their structural and technological improvement, the methods of tightness control used in domestic and foreign shipbuilding are considered.

AN ECONOMIC STUDY OF THE FISHING SECTOR IN NORTH SINAI

North Sinai is considered one of the most important marine fisheries governorates due to the multiple fish sources, both the Mediterranean coast, which covers an area of ​​about 3.2 million fad. and Bardwell Lagoon, which covers an area of ​​about 160 thousand fad. North Sinai Governorate has witnessed a decrease in the quantity of caught fish from about 5121 tons in 2013, to about 4416 tons in 2017, which resulted in high prices of fish, especially the mullet family from about L.E. 20/kg in 2013, to about L.E. 45/kg in 2017. The research aims to identify the current status of fishing activity within the different fishing gears in North Sinai, whether by studying the relative importance of the quantities of caught fish, according to the class, or review all the economic variables of the various fishing gears related to the nature of the activity. The research was based on the method of descriptive and quantitative analysis of the variables under measurement. The study relied on the secondary data published by the General Authority for Fish Resources Development and the CAPM. The preliminary data were obtained through a random stratified sample of 123 boats, 41 of which were inside El-Arish seaport and the rest were from Bardwell Lagoon boats. The results indicated that the average quantity of caught fish in El-Arish seaport during the period (2000-2017). It reached about 2083 tons, of which sardines contribute about 72.3%, and the quantity of caught fish by a statistically significant amount of about 104.5 tons, an annual decrease of about 5%. of the fish, the results indicated that the overall average amount of caught fish was about 3859 tones, of which the fish of the mullet family contributed about 25.7% during the same period. The results showed that the mullet, sea bass and grouper/sea weed fish were increasing annually by a statistically significant amount of about 24.7, 3.1 and 1 ton, with an annual growth rate of 2.5%, 6.1% and 5.8% respectively. The results indicated that the volume of investments in fishing activity amounted to about L.E. 175.4 million (equivalent to about L.E. 131 thousand/boat), Bardwell Lagoon contributed to by about 78.2% and the amount of caught fish about 24.1, 4 tons (equivalent to about 3080 kg/boat), Bardwell Lagoon contributed by about 73.8%. The value of caught fish for fishing boats amounted to about L.E. 134.1 million (equivalent to about L.E. 100.1 thousand/boat), Bardweel Lagoon contributed by about 83.2% and the total fishing costs reached about L.E. 105.4 million (equivalent to about L.E. 78.7 thousand/boat), Bardwell Lagoon contributed by about 74%. Total net revenues were about L.E. 44 million (L.E. 32.9 thousand/boat). The total added value of Fishing activity in North Sinai is about L.E. 86.4 million (about L.E. 64.5 thousand/boat), Bardwell Lagoon contributed by about 72.8%. Finally, the investment efficiency of the Debba boats, the Bawasa boats inside Bardwell Lagoon, the small boats, and the large boats inside the seaport of El-Arish reached about 0.246, 0.242, 0.299 and 0.17. The fishing efficiency was about 97.1%, 92.6%, 94.3% and 89.3%. In general, the Bardwell boats outperformed their counterparts in El-Arish seaport, and the small boats outperformed their large counterparts in El-Arish seaport. The research recommends increasing the number of small boats inside the seaport, in return for not allowing large boats to operate inside the sea port in El-Arish.

Remittances and Small-Scale Coastal Fishing in a Developing Country

Remittances to developing countries exceed $550 billion annually. Although many poor rural households that depend on these remittances also harvest local common-pool resources, few studies explore this relationship. We develop a dynamic model of a coastal fishing household with remittance income. Remittances increase fishing capital investment if households perceive current consumption to be scarce relative to discounted future consumption. This can occur if households heavily discount the future or expect fishing yields to recover. In an empirical application to a Malaysian fishery, we find that households with greater remittance receipts from family migrants either had larger boats and more hired labor, or were more likely to invest in labor-saving capital equipment. These relationships hold most strongly among small-scale artisanal fishers, who are most likely to be financially constrained and more heavily discount the future. We discuss the implications for broader remittance policies in comparison to traditional fisheries management policies.

RIDDLES OF THE PREDYNASTIC PETROGLYPHS ADJUSTED FOR CLIMATE AND HYDROLOGY: BOATS (AND RIVERS?) IN THE UPPER EGYPTIAN EASTERN WADIS

Prehistoric rock drawings of large boats in wadis of the central Eastern Desert, Egypt, divided their investigators into two main groups with quite different views about their origins and cultural affiliation. One of the groups (P. Červiček et al.) insisted on ‘religious’ (cultic, magic, etc.) nature of these petroglyphs attributing them to local traditions but actually tearing away from the reality, primarily on the ground that boats could have never come to be in the desert many tens of kilometers from both the Nile and the Red Sea. Another one, following ideas of W. M. Flinders Petrie, interpreted these boat images as ships of a ‘Dynastic Race’ of oversea invaders who conquered Egypt and consolidated her under their power. This hypothesis, once disapproved by most of archaeologists and Egyptologists, has recently acquired many new adherents; it assumes, in particular, the most real rivers to have flown at the time of the earliest boat petroglyphs (5th to 4th Millennia B.C.) along Wadi Hammamat and Wadi Barramiya, where short routes pass from the Red Sea coast to the Nile. Even rejecting Petrie’s ‘diffusionistic’ version on the whole, one cannot ignore the palaeogeographical fact that the climate of Predynastic Egypt was moist, characterized by monsoon rains which, in combination with geomorphology of the Eastern Desert, could only have favoured here in the period under consideration the formation of regular tributaries of the Nile.

Variasjon i praksis? Sammenføyingsteknikk – og materiale i nordnorske jernalderbåter.

Variation in practice? Joining-techniques in North Norwegian iron age boatsThe iron age burial custom where individuals are placed in seafaring vessels has traditionally been associated with large ships or smaller clinker build boats, such as the famous Oseberg ship found in Norway or the Nydam boat from Denmark. The overall impression of boats from this period have thus been that most of the vessels were constructed and joined with iron rivets consisting of a square nail and a dish shaped washer called a rove. A closer study of archaeological remains from boat burials in Northern Norway has revealed that this might not have been the case. By investigating the number and location of the rivets within the burial, several boats appear not to have been purely “clinker built”, but also fastened by a so called “sewing technique”, traditionally associated with older or Sami boatbuilding traditions. In addition, one of the newly found boat burials from Hillesøy in Troms county contained a boat completely lacking iron rivets. The main result of detailed comparison of all Iron Age boat burials from Northern Norway is exemplified by a selection of boats demonstrating varied use of joining-techniques. Furthermore, this article explores the contextual setting of these boats, arguing that the chosen boatbuilding techniques affected the functional aspects of the vessels and is thus related to their maritime activities.

Pump it up [Marine Applications

Water jets are no longer used just for thrill-seeking jet-skiers. now larger boats in a variety of applications are using the technology for propulsion - so what's powering th trend?

Colonization of fiber-glass plates by benthic diatoms from subtidal sediment off the coast of Yucatan, Mexico

Benthic diatoms thrive in many types of substrata, either natural or alternative such as the surfaces of large and small boats in which colonization by micro- and macro-organisms (fouling) represents an important economic and environmental problem. Addressing this issue is difficult given the scarce information on benthic diatoms one of the main micro-fouling settlers. Thus, this study aimss to describe the colonization process by diatoms on fiber-glass plates and construct a floristic list of the diatom taxa growing both on these surfaces and their likely source the subtidal bottom sediment. The study was conducted at a coastal site off Telchac, Yucatan (Mexico), where fiber-glass plates were laid over the bottom sediment at a depth of 10 m during four months. Sampling was carried out over successive spaced points in time (1st, 3rd, 4th, 8th, 12th and 16th weeks) after the initial immersion of the plates. At the end 88 taxa growing on the plates and sediment were identified, the most abundant ones being Cocconeis scutellum var. parva, Cymatosira lorenziana, Paralia sulcata, Delphineis surirella var. australis, Actinoptychus senarius, Grammatophora marina and Shionodiscus oestrupii. Included were two new records for the Mexican littorals: Cocconeis latestriata and Navicula uniseriata. Overall species composition differs from previous studies in the area, to which forty-seven taxa are added here, increasing their total number to 210. Our results show the changes in the species composition of the taxocenosis over time, during the initial colonization period, i.e., the period during which there is no intense competition for space. The high percentage of common species between the plates and sediment (similarity) support the hypothesis that subtidal sediment is the most likely source for diatoms colonizing the plates.

The plight of some of the poorest of the poor: vulnerabilities of fishing families on Kutubdia Island, Bangladesh

ABSTRACTGlobally, fisheries are important economic resources and support many coastal communities, but the people that rely on fishing experience a range of environmental hazards. This research surveyed 300 fishing households on Kutubdia Island, Bangladesh, regarding their fishing activities and the conditions and perceptions of risk while fishing at sea. This is an artisanal fishery of small boats used for day trips, and larger but still simple boats used for multi-day trips farther offshore. Many households (62%) reported sickness or health problems while at sea. Medicine or first aid kits are carried by only 35% of the boats. Hazards encountered at sea included bad weather (69%), pirates (60%), unfriendly encounters with larger boats (20%), and engine failure (13%). The 300 households reported that 109 fishers had been lost at sea during the past 21 years. From this we estimate an annual death rate of 1335 per 100,000 fishers here, making it among the most dangerous in the world. Bangladesh needs a regulatory framework for its fisheries to include environmental, economic, political, cultural, and social components. Such a regulatory arrangement would support the Kutubdia fishers and should be incorporated into Bangladesh’s national policy for achieving its sustainability goals.

Determinants of Catch Sales in Ghanaian Artisanal Fisheries

The study examined the determinants of catch sales of artisanal fishers through wealthy middle women in fishing communities of Ghana, often known as fish mothers or “fish mongers”. The effects of selected variables were examined with a double hurdle model. Self-financing was found to negatively affect the fishers’ sale of fish catch through fish mothers. The fishers were 19% less likely to sell to fish mothers if they self-finance, and that self-financing will result in a 10% downward unconditional change on the percentage of fish sold to the fish mothers. Factors that positively influenced the sale of fish catch through the fish mothers were price, percentage of high value fishes, size of boat, fishing experience, and number of fishing trips conducted in a year. The estimated average partial effects of boat size had the strongest effect with about 146% and 91% change, respectively on conditional and unconditional effect on the percentage of catch sales sold through the fish mothers. Overall, the study shows that long-term consistent economic and investment considerations such as investing in larger boats are important drivers for fishers’ choice of selling catches through fish mothers. The main implication of the results is that fishers need some economic leverage such as access to formal capital and financial resources to incentivize them to exercise control over their marketing activities so that they can receive a higher profit from their fishing operations. This is important for the sustainability of coastal fisheries communities and the sector as a whole. Artisanal fishers need resources such as low interest loans and market information systems that will enable them to negotiate prices for their fish catch with fish mothers.

Protection of Traditional Fishermen in The Granting of Fishery Licenses in Indonesia

The granting of fishing licenses for large vessels is very detrimental to the existence of small fishermen. Small fishermen or so-called traditional fishermen are powerless to face the dominance of fishing pens and licenses by large boats. This study aims to determine the rare step in providing protection to traditional Indonesian fishermen on the granting of fishing licenses for large companies in Indonesia. This research is an empirical juridical research using statutory uproach approach, conceptual aproach, and comparative approach. Then analyzed using synthesis analysis. The results show that traditional fishermen tend not to have adequate legal protection in terms of fishing in Indonesian waters. Traditional fishermen tend to be allowed to compete with large vessels that have licenses to catch fish in the Indonesian territory. The granting of fishing licenses is not accompanied by certain obligations associated with traditional fishermen protection. If observed, the permit should have a fishing license charging certain liability obligations for the permit holder.

Boat anchoring pressure on coastal seabed: Quantification and bias estimation using AIS data

Global shipping is economically important, but has many adverse environmental effects. Anchoring contributes greatly to this adverse impact, as it is responsible for mechanical disturbance of highly sensitive marine habitats. Recovery of these ecosystems is limited by slow regrowth. Anchoring pressure on coastal seabed habitats was estimated using AIS (Automatic Identification System) data along 1800km of Mediterranean coastline between 2010 and 2015. A comparison with field observations showed that these results were most consistent for large boats (>50m). An analysis of AIS data coupled with a seabed map showed that around 30% of the habitats between 0 and −80m exhibited anchoring pressure. Posidonia oceanica seagrass beds were the most impacted habitat in terms of duration. This methodology efficiently estimates spatial and temporal anchoring pressure principally due to large boats and should interest managers of marine protected areas as much as coastline managers.

Variações nas capturas das lagostas vermelha (Panulirus meripurpuratus), verde (Panulirus laevicauda Latreille, 1817) e sapata (Scyllarides brasiliensis Rathbun, 1906) na costa de Pernambuco

Lagostas são valiosos recursos pesqueiros na costa nordeste do Brasil. No estado de Pernambuco, as capturas das lagostas vermelhas (Panulirus meripurpuratus) e verde (Panulirus laevicauda) foram elevadas, enquanto as da lagosta sapata (Scyllarides brasiliensis), reduzidas. Neste artigo, as variações mensais e anuais das capturas foram analisadas nos desembarques das três espécies entre 1999 e 2006. De maneira geral, a lagosta vermelha foi predominante. As capturas das lagostas vermelha e verde decresceram rapidamente a partir do iní­­cio da temporada de pesca, logo após o defeso, padrão esse não observado para a lagosta sapata. As capturas anuais provenientes das embarcações de comprimento pequeno ou intermediário foram maiores que as das embarcações de maior porte. São José da Coroa Grande, seguida do Recife, foi a cidade em que se verificaram as maiores quantidades desembarcadas. Houve zonação espacial no que diz respeito í­Â s proporções das três espécies nas capturas anuais. A lagosta vermelha foi amplamente dominante nas capturas da costa sul, onde a sapata não foi incomum. Na costa norte, a lagosta sapata foi rara, e a proporção de lagosta verde foi alta e similar í­Â da lagosta vermelha.

Application of aerospace structural models to marine engineering

The large container ships and fast patrol boats are complex marine structures. Therefore, their global mechanical behaviour has long been modeled mostly by refined beam theories. Important issues of cross section warping and bending-torsion coupling have been addressed by introducing special functions in these theories with inherent assumptions and thus compromising their robustness. The 3D solid Finite Element (FE) models, on the other hand, are accurate enough but pose high computational cost.In this work, different marine vessel structures have been analysed using the well-known Carrera Unified Formulation (CUF). According to CUF, the governing equations (and consequently the finite element arrays) are written in terms of fundamental nuclei that do not depend on the problem characteristics and the approximation order. Thus, refined models can be developed in an automatic manner. In the present work, a particular class of 1D CUF models that was initially devised for the analysis of aircraft structures has been employed for the analysis of marine structures. This class, which was called Component-Wise (CW), allows one to model complex 3D features, such as inclined hull walls, floors and girders in the form of components. Realistic ship geometries were used to demonstrate the efficacy of the CUF approach. With the same level of accuracy achieved, 1D CUF beam elements require far less number of Degrees of Freedom (DoFs) compared to a 3D solid FE solution.

Two lobster tales: lessons from the convergent evolution of TURFs in Maine (USA) and the Juan Fernández Islands (Chile)

Overexploitation plagues common property marine resources in a seemingly endless replay of the tragedy of the commons. Territorial use rights in fisheries (TURFs) counter this by controlling access and reducing incentives to compete for larger shares of the resource. Two lobster TURF systems evolved convergently in Maine, USA, and Juan Fernandez Islands, Chile. The Homarus americanus H. Milne-Edwards, 1837 lobster fishery in Maine has informal group territories, whereas the Jasus frontalis (H. Milne-Edwards, 1837) fishery in the Juan Fernandez Islands has individually-owned fishing spots called marcas. Both fisheries use small day boats, both have a long history of protecting reproductive and juvenile lobsters, and both evolved informal fishing territories. Although TURFs limited new entrants in both cases, fishing effort grew, prompting both fisheries to support formal limited-entry regulations. Both lobster populations have expanded in recent decades. Maine's 30-yr increase in lobster landings stimulated fishers to use larger boats with increased fishing capacity and range to exploit offshore lobsters that have been increasing in abundance, but where territorial rights do not exist. Nevertheless, trap limits have led to more equitable access. In Juan Fernandez, power winches increased trap-hauling rates, leading some fishers to advocate trap limits. The TURF system of marcas appears to have limited effort, but it has not prevented the accumulation of marcas by individuals. We conclude these TURFs have addressed the problem of exclusion and have growing lobster populations. It is unknown if TURFs can respond effectively to external factors, such as climate change, that may lead to declining populations.