Boat Motor Research Articles

Bench tests of noise-insulating materials

A group of employees of the Scientific, Educational and Production Laboratory "Outboard Boat Motors" of the Department of Water Transport Operation of the Federal State Budgetary Educational Institution "AGTU" achieved certain results in the fight against noise, reflected in a number of patents of noise-insulating hoods of various modifications and publications on the analysis of the frequency spectrum of outboard boat motor noise, evaluation of the effectiveness of outboard motor hoods of small-sized Based on the accumulated scientific research, several proto-types of multilayer means recommended for sound insulation of outboard boat motors have been created. In the conditions of a large range of directions, there is a need to apply single-layer or multi-layer structures to the properties of sound insulation without forming a physical model of the hood, casing. This is due to the fact that the production of a hood model entails a complex technological process, while creating a sample in the form of a plate from the same material is much more profitable in terms of financial, labor and time costs. Based on the needs of the scientific educational and production laboratory of outboard boat motors in the study of noise generated by outboard boat motors and means of combating them, it was decided to create a stand to assess the effectiveness of noise-reducing materials, which will allow modeling the conditions of natural operation of a noise-insulating material without the use of full-scale tests with outboard by motor. The created stand allows testing in two directions. The first direction is the testing of physical models of casings for noise insulation using audio files reproducing the noise of the required equipment. The second direction is the study of materials for their noise-insulating properties when generating waves of different frequencies.

Behavioral responses of native and invasive fishes of the Upper Mississippi River to 100 hp boat motor acoustic stimulus

Behavioral responses of native and invasive fishes of the Upper Mississippi River to 100 hp boat motor acoustic stimulus

Measurement and analysis of underwater noise of offshore mussel suspended farming waters

Anthropogenic noise pollutions are gradually increasing in the world, especially in coastal waters due to shipping and seismic exploration. However, the need for high-quality aquatic products has led to more and more marine suspended farming, which may add to the new sources of low-frequency anthropogenic noises in the ocean. Waters around the Gouqi Island, one of the major reef islands in the northern Zhoushan Archipelago, are considered as important suspended farming waters of mussel. The units of suspended farming facilities composed of aquaculture lines with attached mussels, or the sleeves, are suspended in the surface layer by buoys. The length of the sleeves is 2.3-2.8 m and the water layer occupied by the aquaculture system is about 3.5 m. These suspended farming facilities can reduce the current speed significantly. In this paper, the underwater noises of mussel suspended farming waters of Gouqi Island were measured by a passive monitor system at two sites (inside and outside mussel farming waters) with depths of 5 m and 10 m, and boat noises were also recorded to determine the noise source. All sounds were monitored prior to record to ensure the minimum self-noise, and at least 10 recordings were made and separated by at least 5 min. Power spectra of sound recordings were presented as 1/3-octave sound pressure level (SPL) in dB. Results showed that the main frequency of boat motor noise was 250 Hz, and its SPL at 5 m (114.7± 1.7) dB was greater than that at 10 m (97.4±0.9) dB when the boat was anchored. There were three peak frequencies (63 Hz, 250 Hz, 500 Hz) of underwater noises generated outside the mussel farming waters, where the SPL of 250 Hz at 5m was greater than that at 10m, indicating that the environmental noise outside mussel farming waters was greatly affected by fishing boat. The average environmental noise SPL was (87.7±13.7) dB inside the mussel farming waters, there were also three peak frequencies (63 Hz, 250 Hz, 500 Hz), where SPL of 500 Hz at 10 m (85.13±0.5) dB was greater than taht at 5 m (179.4±0.9) dB, indicating that the suspended mussel farming facilities were the main source of 500 Hz inside the mussel farming waters. This vertical distribution of marine environmental noise may be due to the blocking effect of mussel suspended farming facilities on tidal currents. Owing to that tidal current velocity was reduced in the surface layer, underwater noise level at bottom was greater than that in the surface layer. The underwater noise from suspended farming facilities can contribute significantly to the local ocean noise, and it is clear that the frequency of the suspended farming noise overlaps with the frequency used for acoustic communication in fish. It is necessary to increase our understanding of marine soundscapes, especially when ocean soundscapes continue to be suffered from human activity. In the future, more studies on the effects of noise from aquaculture facilities on the biology and ecology of fish are needed to fill the missing link in acoustic ecology.

Anthropogenic Sound in the Sea: Are Ascidians Affected?

Sound pollution in the marine environment has been increasing largely due to anthropogenic sources such as vessel traffic, coastal development, fossil fuel extraction, and military exercises. Studies determining the effects of anthropogenic sound on marine organisms have mostly focused on vertebrates, namely fish and marine mammals; however, less research has been done to study the effects of sound on marine invertebrates. The goal of this research is to examine the effect of anthropogenic sound on the ascidian Styela plicata (Lesueur, 1823) in Tampa Bay, FL. A total of 48 ascidians were collected from 2 sites with differing amounts of boat traffic and thus different anthropogenic soundscapes. Ascidians were individually exposed to 3 separate stimuli: a recording of a boat motor, a song recording, and a water current to simulate turbulence. Ascidian reactions were recorded as the frequency of siphon closing events and the length of time the siphons remained closed after disturbance. Ascidians from both sites increased the frequency and longevity of siphon closure events in response to anthropogenic stimuli but showed only a minor difference in response between sample sites. Research into the effect of anthropogenic sound on invertebrates such as ascidians and their symbionts may provide a better understanding of larger scale ecological impacts from such disturbances.

Анализ частотного спектра шума подвесного лодочного мотора Hangkai 4.0 при капотировании

The article deals with the results of experiments on measuring the Hangkai 4.0 outboard motor when using various types of noise-insulating hoods. The tests were carried out in accordance with GOST ISO 14509-1-2015 “Small Vessels. Noise measurement of small motor pleasure craft. Part 1. Noise of a passing ship” at full speed with the engine speed 4500 rev/min and motor power 4 HP. Measurements were carried out when the vessel was at a distance of 25 metres both sides with different options covering outboard motor. The average noise level and its frequency spectrum were measured, and the effectiveness of various types of hoods was evaluated. In the course of the experiment there was used a standard plastic hood of the Hangkai 4.0 engine, a noise-insulating hood (plastic hood, glued inside with automotive foil noise insulation) and an author's combined noise-insulating hood Kaponistr. Description and structural elements of Kaponistr are presented; it has been stated that the hood design was patented as a useful model in 2019. In the result of conducted experiments it has been inferred that the external noise level of the Hangkai 4.0 outboard motor (without hood) does not exceed 74.3 dBA, but is at the level of the permissible value of 75 dBA, so, when operating, the motor needs a standard hood. The prevailing frequency range of an outboard boat motor is within 300 - 2500 Hz. It has been inferred that each type of nosing (standard, sound-proof, combined, without hood) reduces the noise level of the outboard motor. The greatest effect of reducing external noise is observed when using a combined hood Kaponistr at a frequency of 800 Hz by 19.4 dBA or by 27%. In the research there were used the control and measuring devices (sound level meter, vibrometer, spectrum analyzer Ekofizika-110 (white); acoustic calibrator AK-1000) and software (Signal+3G Light manufactured by PKF Digital Instruments, LLC).

Faktor–Faktor yang Memengaruhi Optimalisasi Penangkapan Ikan dengan Metode Transformasi Box Cox pada Regresi Linier Berganda

In general, the ratio of the ocean and land area on this earth is 70 to 30. Many potentials of water can be used to promote human well-being. Even today, many developed countries from all over the world are competing to advance their maritime activities and their auspices for the country's interests so that the role of the sea becomes dominant for developing of the countries. One of the most common marine activities people do is sea fishing. the marine and fisheries sector has enormous potential to become a national economist. In Indonesia, many people depend on the fisheries sector. So, in this research that will be discussed is to determine the model of the number of marine fish production in East Java Province with Box-Cox Transformation method on Multiple Linear Regression to get significant control variable on the amount of sea fish production in East Java Province. The result of regression using Box-Cox transform shows that some variables such as the number of fishermen, fishing equipment, and boat or fishing boat motor have a significant influence on R2 89.3%. With this model, it is hoped to be one strategy to increase the number of fishing through the selection of appropriate control variables.

A Novel System for the Deployment and Retrieval of Trawl Gear from the Bow of a Small Research Vessel

Abstract Research vessel crews have increasingly applied trawling gear in a diversity of freshwater habitats, including river systems. Crews typically deploy and retrieve trawling gear by hand or with hydraulic winches. These methods are often labor intensive and require crews of three or more people to operate safely. Additionally, unless the research vessel has an inboard engine with power take-off capabilities, hydraulic winches will need to be powered by a generator, requiring additional maintenance and creating a loud work environment. We describe a new system for the deployment and retrieval of trawling gear that is suitable for smaller vessels where a hydraulic system may not be practical. This system utilizes electric line haulers mounted on davits at the bow of the boat. The line haulers are retrofitted with a novel mechanism for loading the trawl line into the line hauler pulley, allowing deployment and retrieval of many types of trawl gear by one deckhand and one boat operator. The electric trawl retrieval system is powered by a battery bank that charges from the boat motor, thereby reducing risk of hearing damage from generator noise. We have designed it to be interchangeable and portable amongst different research vessels, which increases sampling efficiency and reduces costs.

Influence of boat noises on escape behaviour of white-spotted eagle ray Aetobatus ocellatus at Moorea Island (French Polynesia)

The present study tested different sounds that could disturb eagle rays (Aetobatus ocellatus) during their foraging activities at Moorea, French Polynesia. Results showed that artificial white sound and single-frequency tones (40Hz, 600Hz or 1kHz) did not have an effect on rays (at least 90% of rays continued to forage over sand), while playbacks of boat motor sound significantly disturbed rays during foraging activity (60% exhibited an escape behaviour). Overall, our study highlighted the negative effect of boat noises on the foraging activity of eagle rays. These noises produced by boat traffic could, however, have some positive effects for marine aquaculture if they could be used as a deterrent to repel the eagle rays, main predators of the pearl oysters.

Pollutant Concentrations and Toxic Effects on the Red Alga Ceramium tenuicorne of Sediments from Natural Harbors and Small Boat Harbors on the West Coast of Sweden.

This investigation set out to analyze the toxicity of surface sediments in a number of natural harbors and small boat harbors on the west coast of Sweden. This was done with the growth inhibition method with Ceramium tenuicorne. Also, concentrations of copper (Cu), lead (Pb), zinc (Zn), irgarol, organotin compounds, and polycyclic aromatic hydrocarbons (PAHs) in the sediments were analyzed. The small boat harbors were heavily polluted by Cu, Zn, butyltins, and PAHs, and to a lesser extent by Pb. The Cu, Pb, Zn, and butyltins probably originated from their past and/or present use in antifouling paints, whereas the PAHs probably had multiple sources, including boat motor exhausts. The measured toxicity of the sediment was generally related to their Cu, Zn, and butyltin content, although other toxic substances than those analyzed here probably contributed to the toxicity in some of the harbors. The natural harbor sediments contained less pollutants and were less toxic than the small boat harbor sediments. Nevertheless, our data indicate that the boating pressure today may be high enough to produce toxic effects even in natural harbors in pristine areas. The strongest relationship between toxicity and the major pollutants was obtained when the sediment toxicity was expressed as gram wet weight per liter compared with gram dry weight per liter and gram total organic carbon per liter. Hence, for pollutants that can be elutriated with natural sea water, sediment toxicity expressed as gram wet weight per liter appears preferable.

Bioacoustic characterization of a coastal marine soundscape in Quintana Roo, Mexico

Wild dolphins are exposed to a variety of biological and other natural and anthropogenic sounds. Several species of dolphins, including bottlenose dolphins (Tursiops truncatus), have been documented in the MesoAmerican Reef (MAR) region; however, there is little to no scientific monitoring of these populations. Characterizing the soundscape of wild dolphins on a section of the MAR would facilitate understanding the acoustic nature of this dolphin habitat. Passive Acoustic Monitoring using an Ecological Acoustic Recorder was conducted for one year off the coast of Quintana Roo, Mexico, just north of Isla Mujeres, a site where dolphins are known to be frequent. The soundscape was typified by natural sounds, however there was important periodic contribution by anthropogenic sources. Boat motor noise contributed to higher SPLrms during the day than in the night and contributed to noise between 500 Hz and 25 kHz, which is consistent with small vessels. While boat motor noise was not as frequent as fish sounds nor as pervasive as snapping shrimp sounds, when present it potentially overwhelms the natural soundscape. Anthropogenic characteristics of this soundscape have implications for dolphin welfare and regulations in the nearby marine protected areas.

Performance and emission testing of a bi-fuel outboard spark-ignition engine

With the increasing concern about the future availability of gasoline and continuously stringent engine emission regulatory standards, the need for an alternative to gasoline as a primary engine fuel is becoming increasingly important. One proposed alternative is to use natural gas due to its availability, low cost, and generally reduced engine emissions. However, due to volumetric efficiency losses, the conversion of a standard spark-ignition engine originally operating on gasoline to run on natural gas has been shown to produce considerable power reductions. Additionally, improperly tuned natural gas conversion kits could potentially increase certain emissions’ quantities compared to gasoline. This work reports the results of an experiment designed to characterize the performance and emissions of a commonly used gasoline outboard boat motor converted to run on natural gas. Reported are the comparisons between gasoline and natural gas for the widely used engine operating parameters for gauging engine performance related to power output and harmful emissions, including oxides of nitrogen, unburned hydrocarbons, and carbon monoxide, for comparison of the two test fuels. The results indicate that operation on natural gas greatly reduces harmful hydrocarbon and carbon monoxide emissions at the cost of reduced engine power output and potentially increased oxides of nitrogen emissions.

The Left-To-Die Boat: Review 2

In March 2011 an inflatable boat carrying 72 asylum seekers from sub-Saharan Africa set out from the coast of Libya hoping to reach the Italian island of Lampedusa. As one Italian official commented, sailing from Libya towards Italy should have been ‘a bit like doing a slalom between military ships’. Yet as, out of fuel, supplies of food and water dwindled to nothing and the people on board began to get sick and die, the boat continued to drift and no help came. Eventually it floated all the way back to the Libyan coast. Of the 50 men, 20 women and two babies who set out to sea, only eleven remained alive. Sharon Davis and Geoff Parish reconstruct this tragedy through interviews with five young men who survived the trip. Their first-person accounts of the journey are augmented by interviews with sympathetic Dutch politician Tineke, Rome-based Eritrean Priest Father Mussie Zerai, who was contacted by the passengers by satellite phobe, human rights investigator Lorenzo Pezzani, who forensically reconstructed the boat’s movements, and dour NATO spokesperson Oana Lungescu. One survivor (Abu Kurke) speaks in halting English; for the others the vernacular is faded under voice-overs. It is raw, simple narrative, expertly selected and edited to move the story seamlessly forward while also allowing listeners time to form mental images of the boat and its passengers and to absorb the emotional impact of what they are hearing. The survivors’ individual accounts overlap and repeat to poetic effect, underscoring the veracity of their testimony. The survivors’ tale floats on a bed of sound – the splash of waves; the hum of a boat motor; restrained, ominous music (with cello predominating), and the occasionally distant chime from an old clock tower marking the relentless passing of time and its deadly impact on the voyage. The radio makers’ approach is dignified, restrained and powerful. Just as the clean lines of minimalist architecture can rely on sophisticated engineering, so the apparent simplicity of a chronological account conceals the artistry, deep thought and sheer hard work of radio production. A strong undercurrent of anger flows through the documentary, and we are given strong encouragement to doubt that NATO has been fully truthful in its response to the tragedy. The Left-To-Die Boat won a United Nations Association of Australia Media Peace Prize and was shortlisted for a Sony Academy award (UK), the New South Wales Premier's Literary Awards and the Australian Human Rights Awards.

Oxygen depletion induced by adding whey to an enclosure in an acidic mine pit lake

Neutralization of acidic mine pit lakes by biotechnological means results in the production of labile metal-sulfides. These reaction products can theoretically be stored sustainably in the lake, provided reducing conditions are maintained at the lake bottom. In a field mesocosm experiment, we tested, if reducing conditions can be maintained in an acidic mine pit lake by the addition of a complex organic substrate. An enclosure of 30 m diameter was covered by a floating foil, and whey was repeatedly added to the water column to stimulate microbial respiration. A suspension of whey was successfully mixed into the enclosure by means of a boat motor. Whey was completely dissolved and subsequently consumed by microbial respiration in the water column. This resulted in oxygen consumption leading to anoxic conditions. About 10 mmol m −2 d −1 oxygen permanently entered the enclosure from the atmosphere, while a minor amount of oxygen was produced by primary production. By careful monitoring and repeated additions, it was possible to keep the bottom of the enclosure permanently anoxic, even during mixing periods in autumn and spring. Fe 3+, however, was not reduced significantly. A laboratory experiment revealed that microbial iron reduction was inhibited by both low concentrations of organic substrates and low temperature. Since Fe III is a potential oxidizing agent, it is questionable, if the stability of metal-sulfides in acidic mine pit lakes can be increased by the addition of complex organic substrates.

Analysis of the fishing effort of the Mexican longline tuna fleet operating in the Gulf of Mexico in 2004

The Gulf of Mexico yellowfin tuna (YFT) longline fishing effort for 2004 was analyzed. The data used to describe the longline characteristics and estimate the catch efficiency of the vessels (catch in number of organisms per trip) were obtained from fishing reports made by onboard scientific observers from the Mexican Tuna Exploitation and Dolphin Protection Program, covering 100% of the trips. To compare the catch per trip and determine the main aspects influencing it, generalized linear models were applied. To explain differences in efficiency, the following explanatory variables were considered: boat, bait, equipment, area, trimester, type of hook, number of hooks, temperature, longline total length, gangion length, trip duration (number of days), number of sets per trip, gear deployment time, longline soaking time, and hauling time. The model explained 57.5% of the variability of the catch. The variables that had the greatest influence on efficiency were boat, bait, trimester, equipment, number of sets per trip, and trip duration. The variable boat was the most important, suggesting that the Mexican YFT fleet operating in the Gulf of Mexico could be heterogeneous. This variable may include the experience of the captain and/or crew, boat age, motor characteristics and maintenance, or even crew comfort. The results should be considered preliminary since only one year was analyzed.

Anthropogenic noise affects risk assessment and attention: the distracted prey hypothesis

Many studies have focused on the effects of anthropogenic noise on animal communication, but only a few have looked at its effect on other behavioural systems. We designed a playback experiment to test the effect of noise on predation risk assessment. We found that in response to boat motor playback, Caribbean hermit crabs (Coenobita clypeatus) allowed a simulated predator to approach closer before they hid. Two hypotheses may explain how boat noise affected risk assessment: it masked an approaching predator's sound; and/or it reallocated some of the crabs' finite attention, effectively distracting them, and thus preventing them from responding to an approaching threat. We found no support for the first hypothesis: a silent looming object still got closer during boat motor playbacks than during silence. However, we found support for the attentional hypothesis: when we added flashing lights to the boat motor noise to further distract the hermit crabs, we were able to approach the crabs more closely than with the noise alone. Anthropogenic sounds may thus distract prey and make them more vulnerable to predation.

Factors Influencing Radio Wave Transmission and Reception: Use of Radiotelemetry in Large River Systems

AbstractMany technical and environmental variables affect radio wave transmission and reception in aquatic environments. We used a controlled experimental design in three large North American rivers (Illinois and Mississippi rivers, Illinois, and Skeena River, British Columbia) to examine the effects of water conductivity, transmitter depth, electromagnetic noise, antenna height, and transmitter type on detection distance. Detection distance was significantly affected by water conductivity, transmitter depth, and electromagnetic noise from a boat motor. Detection distance and maximum depth of signal reception increased with decreasing conductivity except at conductivities from 60 to 90 μS/cm (Skeena River). In contrast to terrestrial radiotelemetry, antenna height did not significantly affect detection distance. We also determined that a transmitter with a 3.5‐V battery had an approximately 2.5 times greater detection distance than a transmitter with a 1.5‐V battery. We provide quantitative results for several variables influencing radio wave transmission and reception, and we present two regression equations that can be used by researchers to obtain estimated detection distances in rivers of similar conductivity and depth. Furthermore, we compared our detection distances with those calculated from theoretical equations and found that our field results yielded higher detection distances. We strongly believe that there are gaps between results reported in technical papers and those obtained in field method studies; we argue for more collaborative research between aquatic telemetry users and engineers to reduce the current need for trial and error in telemetry study design.

53-Year-Old Man With a Swollen Finger

53-Year-Old Man With a Swollen Finger

Exotic Marine Macroalga ( Enteromorpha flexuosa) Reaches Bloom Proportions in a Coastal Lake of Lake Michigan

The exotic marine algae Enteromorpha flexuosa subsp. flexuosa and subsp. paradoxa were first observed in Muskegon Lake during autumn 2003. In September 2003, the littoral zone had between 10 and 80% cover of macroalgae, which grew largely on submerged macrophytes, and was composed almost entirely of Enteromorpha. Enteromorpha formed dense mats, fouled the boat motor and was found washed up in large quantities on the shoreline. Eleven other waterbodies in the region were surveyed: two others had Enteromorpha composing 5 to 20% of the macroalgal community, four had no apparent macroalgae and the remaining five were dominated by Cladophora. Possible reasons for the success of Enteromorpha in these coastal lakes include nutrient enrichment, a history of industrial activity resulting in increased salinity of the water, as well as an absence of grazing pressure. Potential effects on littoral zone food webs are uncertain; however, we found low epiphytic diatom densities on Enteromorpha, which is a concern in these systems where epiphytic diatoms are important components of the food web. Currently, this new macroalgal invader has been found in only three coastal waterbodies of Lake Michigan; however, it is possible that Enteromorpha could spread beyond its current range, if it has not already done so. Given its ability to form nuisance blooms in a coastal lake of Lake Michigan and its reported impacts in marine systems, it is imperative that the possible impacts of this invasive marine macroalga on the Great Lakes ecosystem be determined.

Cost analysis of modern hunting among the inuit of the Canadian central arctic

Abstract In northern Canada the traditional Inuit subsistence economy and means of transportation have undergone changes through the introduction of such technological innovations as the rifle, the boat motor, and the snowmobile. These innovations and the related changes have influenced hunting and trapping methods as well as the yield from hunting which, today, not only has to provide for the daily needs with regard to food and clothing, but also for the necessary monetary means to acquire and operate modern equipment. The paper presents data that were collected in Repulse Bay, N.W.T., in 1973 in order to arrive at a cost analysis of modern hunting within the superimposed framework of a “mixed economy”; based on both the traditional subsistence economy and wage employment. (The translation is by William Barr, University of Saskatchewan, Saskatoon.)