Integration of fisheries acoustics surveys and bathymetric mapping to characterize midwater-seafloor habitats of US Virgin Islands and Puerto Rico (2008-2010)

NOAA’s Coral Reef Conservation program (CRCP) develops coral reef management priorities by bringing together various partners to better understand threats to coral reef ecosystems with the goal of conserving, protecting and restoring these resources. Place-based and ecosystem-based management approaches employed by CRCP require that spatially explicit information about benthic habitats and fish utilization are available to characterize coral reef ecosystems and set conservation priorities. To accomplish this, seafloor habitat mapping of coral reefs around the U.S. Virgin Islands (USVI) and Puerto Rico has been ongoing since 2004. In 2008, fishery acoustics surveys were added to NOAA survey missions in the USVI and Puerto Rico to assess fish distribution and abundance in relation to benthic habitats in high priority conservation areas. NOAA’s National Centers for Coastal Ocean Science (NCCOS) have developed fisheries acoustics survey capabilities onboard the NOAA ship Nancy Foster to complement the CRCP seafloor habitat mapping effort spearheaded by the Center for Coastal Monitoring and Assessment Biogeography Branch (CCMA-BB). The integration of these activities has evolved on the Nancy Foster over the three years summarized in this report. A strategy for improved operations and products has emerged over that time. Not only has the concurrent operation of multibeam and fisheries acoustics surveys been beneficial in terms of optimizing ship time and resources, this joint effort has advanced an integrated approach to characterizing bottom and mid-water habitats and the fishes associated with them. CCMA conducts multibeam surveys to systematically map and characterize coral reef ecosystems, resulting in products such as high resolution bathymetric maps, backscatter information, and benthic habitat classification maps. These products focus on benthic features and live bottom habitats associated with them. NCCOS Centers (the Center for Coastal Fisheries and Habitat Research and the Center for Coastal Environmental Health and Biomolecular Research) characterize coral reef ecosystems by using fisheries acoustics methods to capture biological information through the entire water column. Spatially-explicit information on marine resources derived from fisheries acoustics surveys, such as maps of fish density, supports marine spatial planning strategies and decision making by providing a biological metric for evaluating coral reef ecosystems and assessing impacts from pollution, fishing pressure, and climate change. Data from fisheries acoustics surveys address management needs by providing a measure of biomass in management areas, detecting spatial and temporal responses in distribution relative to natural and anthropogenic impacts, and identifying hotspots that support high fish abundance or fish aggregations. Fisheries acoustics surveys conducted alongside multibeam mapping efforts inherently couple water column data with information on benthic habitats and provide information on the heterogeneity of both benthic habitats and biota in the water column. Building on this information serves to inform resource managers regarding how fishes are organized around habitat structure and the scale at which these relationships are important. Where resource managers require place-based assessments regarding the location of critical habitats along with high abundances of fish, concurrent multibeam and fisheries acoustics surveys serve as an important tool for characterizing and prioritizing coral reef ecosystems. This report summarizes the evolution of fisheries acoustics surveys onboard the NOAA ship Nancy Foster from 2008 to 2010, in conjunction with multibeam data collection, aimed at characterizing benthic and mid-water habitats in high priority conservation areas around the USVI and Puerto Rico. It also serves as a resource for the continued development of consistent data products derived from acoustic surveys. By focusing on the activities of 2010, this report highlights the progress made to date and illustrates the potential application of fisheries data derived from acoustic surveys to the management of coral reef ecosystems.

Mechanization of fishing craft and the use of improved fishing gear

Since the year 1925, attention has been focused periodically on the stagnation in the local fishing industry, and those who have studied the subject have been unanimous about the need to introduce modern fishing craft which are capable of working more fishing gear. This report outlines the stages through which the evolution of more effective fishing operations has progressed, both in the gradually increasing use of mechanical propulsion for boats and in the adoption of more modern gear and techniques by local fishermen. No reference is made in this report to the operation of deep-sea trawlers (Sivalingam, 1956) a phase of development which has hitherto not influenced the local fishing industry to any appreciable extent.

A mechanical device for eradication of submerged aquatic weeds

This paper embodies details and method of operation of a mechanical device developed for eradication of submerged aquatic weeds. The economics of operation is also discussed.

Reports of the ICSF seminar / workshop on the conditions of fishworkers on distant water vessels, Manila, Philippines, 1-3 February 1991

This ICSF Exchange Programme held in Manila is an offshoot of the Bangkok Conference on “Global Fisheries Trends and Future of Fishworkers” held on January 22–27, 1990. One of the issues raised in that conference was about the operation of Taiwanese fishing vessels outside its territorial waters and the impact of such operations on small fishermen from the countries concerned. The presence of a Taiwanese fishworker as well as an NGO supporter contributed to an enlightening discussion as the former shed light on the sad plight of Taiwanese fishworkers who are the victims of such structural problems. This meaningful exchange between groups of fishermen, particularly Taiwanese and Filipinos, resulted in the plan of the Taiwanese delegation to have some Taiwanese fishermen visit the Philippines and immerse in fishing communities.

A baseline report of water quality and invertebrate assessment in River Hohwa, Lake Albert: final report

Tullow Oil plc is to launch an onshore Early Production System (EPS) of oil drilling rated at 4,000 barrels of oil per day by 2009. The location of the EPS is in the Kaiso-Tonya area of Block 2 Oil Exploration Zone along Lake Albert within the Albertine graben. Tullow Oil plc contracted Environmental Resources Management (ERM) Southern Africa (Pty) Ltd in conjunction with Environmental Assessment Consult Limited (EACL) to undertake an Environmental Impact Assessment (EIA) for pre-construction and operation of the proposed EPS. ERM in association with EACL requested National Fisheries Resources Research Institute (NaFIRRI) to conduct a baseline survey of water quality and invertebrates in River Hohwa. This study was requested as part of an earlier baseline survey conducted at the Kaiso-Ngassa spit oil exploration area in Block 2. It was conducted at five selected sites (Fig. 1 & Table 1) within the Hohwa River basin in the Kaiso-Tonya Exploration Area 2. The study was pertinent because the targeted oil wells for EPS are upstream this river which drains the Kaiso-Ngassa valley into Ngassa lagoon.

Movement of deposited water on turbomachinery rotor blade surfaces

A theoretical approach for calculating the movement of liquid water following deposition onto a turbomachine rotor blade is described. Such a situation can occur during operation of an aero-engine in rain. The equation of motion of the deposited water is developed on an arbitrarily oriented plane triangular surface facet. By dividing the blade surface into a large number of facets and calculating the water trajectory over each one crossed in turn, the overall trajectory can be constructed. Apart from the centrifugal and Coriolis inertia effects, the forces acting on the water arise from the blade surface friction, and the aerodynamic shear and pressure gradient. Non- dimensionalisation of the equations of motion provides considerable insight and a detailed study of water flow on a flat rotating plate set at different stagger angles demonstrates the paramount importance of blade surface friction. The extreme cases of low and high blade friction are examined and it is concluded that the latter (which allows considerable mathematical generalisation) is the most likely in practice. It is also shown that the aerodynamic shear force, but not the pressure force, may influence the water motion. Calculations of water movement on a low-speed compressor blade and the fan blade of a high bypass ratio aero-engine suggest that in low rotational speed situations most of the deposited water is centrifuged rapidly to the blade tip region. Copyright © 2006 by ASME.

Comparative efficiencies of mechanized fishing crafts introduced in India

India started mechanization of fishing craft in early 1950. The traditional craft was subjected to technical scrutiny and some of them mechanized with good results. However, due to limitations inherent in the traditional craft, it was found necessary to develop new series of crafts suitable for the operation of modern fishing gears in areas hitherto unexplored. The impetus given to the development of infrastructure like freezing, canning and ice plants, and quickly expanding export market, increased the demand for marine products, hence craft for immediate, as well as long-term needs had to be introduced. In this article the author discusses design of fishing vessels, information from experience used in development of vessels, designs of distant water vessels, productivity studies, income and expenditure, economic values, production cost, and productivity.

The performance of ejectors driven by sinusoidally unsteady jets

The operation of ejectors driven by a low-speed, sinusoidally unsteady jet has been studied. The thrust augmentation is shown to be highly dependent on the non-dimensional frequency of the driver jet, but independent of its Mach Number. Convective rather than acoustically propagated phenomena dominate the ejector flowfield. Unsteady pressure measurements on the internal surfaces of the ejector have enabled convecting ring vortices to be identified. The impingement of a ring vortex on the leading edge of the ejector causes the peak unsteady body force. The non-dimensional diameter of the ejector is shown to be the only geometric variable that affects the optimum non-dimensional frequency for thrust augmentation. An experimentally optimised geometry is presented. An expression relating the mechanical efficiency and thrust augmentation of the ejector is developed, and shown to be crucially dependent on the degree of unsteadiness in the ejector exit plane.

Fluid mechanics of pulse pressure-gain combustors

The fluid dynamic operation of a valveless pulse combustor has been studied experimentally and numerically. Through phase-locked chemiluminescence and pressure measurements it is shown that mechanical energy is created periodically in the flame surface, with an efficiency of 1.6%. This mechanical energy leaves the pulse combustor through unsteady jets at the aerovalve inlet and the tailpipe exit stations. Two thermodynamically distinct flows are identified: a flow that is transported from inlet to exit and participates in combustion along the way, and a flow that is ingested and then ejected from the combustor without undergoing combustion. It is the latter of these two flows which has the greatest quantity of net work done on it. Copyright © 2008 by the American Institute of Aeronautics and Astronautics, Inc.

Recovery, growth and carcass composition following periods of restricted ration and full feeding in indian major carp, Rohu (Labeo rohita H.)

A 90-day experiment was conducted to determine the effect of restricted ration and full feeding on the recovery growth and carcass compositions of fingerlings (average weight - 20.74 ± 0.13 g) of rohu, Labeo rohita (H.). Rohu fingerlings procured from a local fish breeder were fed with commercial pelleted feed (27% crude protein) during the two-week acclimatization in the laboratory condition. Experimental pelleted diet (30% crude protein) was prepared and the control group (T sub(CFR)) was fed at 3% of body weight for the 90-day trial period. The experimental group T sub(1FR) was fed for three days at 1% of body weight and the next three days at 3% of body weight, T sub(2FR) was fed for seven days at 1% of body weight and the next seven days at 3% of body weight, T sub(3FR) was fed for 15 days at l% of body weight and the 15 days at 3% of body weight and T sub(4FR) was fed for 25 days at 1% of body weight and the next 25 days at 3% of body weight, alternating between 1 and 3% for the specified period during the 90-day trial period. Daily rations were divided into two equal meals per day at 09.00 and 16.00 hours. Average percent survival rate of rohu during the 90-day trial period was more than 90. Percent live weight gain (98.90 ± 0.34, 113.0 ± 5.93, 125.71 ± 11.01 and 141.90 ± 2.89), specific growth rate (1.53 ± 0.01 1.68 ± 0.06, 1.80 ± 0.10 and 1.96 ± 0.02%/d) and absolute growth rate (1.33 ± 0.13, 1.38 ± 0.07, 1.39 ± 0.04 and 1.44 ± 0.07g/d) of the experimental groups (T sub(1FR), T sub(2FR), T sub(3FR) and T sub(4FR) respectively) increased with the advancement of the experiment in comparison to those in control, T sub(CFR) (90.92 ± 5.81%, 1.44 ± 0.07%/d and 1.34 ± 0.20g/d, respectively) and were proportionately correlated with the degree of deprivation probably through the mechanism of increased feed intake (hyperphagia), feed efficiency ratio or gross growth efficiency, protein efficiency ratio and the superior feed conversion ratio reflecting in better performance index. The body length and muscle composition of fish indicated that recovery growth happened due to protein growth but certainly not due to fat deposition in the gut. Feeding at 1 and 3% of body weight alternating over a period of 25 days might economize the culture operation of rohu.

On the importance of ship-bottom fouling by marine organisms: a techno-economic survey

A high attention has been paid for constant research on the preservation of materials in the marine environment. This includes all phases of design, development, applied engineering and economics which may influence the construction and operation of ships and underwater installations.

Economics of gill netting and two boat midwater trawling

The paper deals with the economic aspects of operation of gill netting and two boat midwater trawling conducted off Cochin. The data collected on two boat midwater trawling and gill netting during 1979 and 1980-81 are presented. Gill netting was profitable at the range of 17.5 and 25.2% while two midwater trawling was profitable at the rate of 18.5 %.

Selection of materials for marine instruments

The paper describes the selection of materials for the reliable operation of oceanographic instruments. For selecting the material, raft immersion tests were carried out for one year. Results of the tests are presented. Comparisons between metals were discussed.

Socio-economic and marketing aspects of Laila and Bottom Long Line fisheries in the Kalpitiya peninsula of Sri Lanka

Surrounding Net Fishery (laila) and Bottom Long Line Fishery which operate in the coastal waters of Kalpitiya Peninsula, compete for the same fish resources, resulting in a fishery dispute between the respective fishermen. Both fisheries target demersal as well as mid pelagic fishes, such as travellys (parava), mullets (galmalu) and barracudas (ulava). As the dispute had an adverse impact on the social harmony in the fishing community of the area, a socio-economic survey was conducted to study the underlying factors and to suggest policy measures to resolve the issue. The laila fishermen were resident fishermen in the Kalpitiya Peninsula while bottom long line fishermen were migratory fishermen from Negombo and Chilaw areas in the west coast of Sri Lanka. The Kalpitiya peninsula is located in the North West coast, some 50 km away from the west coast. Although the educational level and literacy rate of the laila community was below that of the bottom long line community, the laila community was economically better off. The net economic returns from laila fishery were superior to that from bottom long line fishery. The boat owner's and crew's share per operation of laila fishery were Rs.3,736 and Rs.947 respectively. The same figures for bottom long line fishery were Rs.588 and Rs.327 respectively. The resource rent from laila fishery was Rs.5,860, however, and much higher than that for bottom long line fishery (Rs.275), showing that the laila fishery exploits the targeted fish resource at a much higher rate compared to bottom long line fishery. This situation badly affects the equitable distribution of resources between the two fishing communities and results in unequal economic gains. Based on the findings of this study, certain input/output controls are proposed to address this problem, among which is the need to increase license fee for laila fishery units to offset the higher exploitation rate of fish resources.