Changes in Behavior, Movement, and Home Ranges of Largemouth Bass Following Large-scale Hydrilla Removal in Lake Seminole, Georgia

About 1,200 ha of hydrilla ( Hydrilla verticillata L.f. Royle) was eliminated in the Spring Creek embayment of Lake Seminole, Georgia, using a drip-delivery application of fluridone (1- methyl-3-phenyl-5-[3-(trifluoromethl) phenyl]-4(1H)-pyridinone) in 2000 and 2001. Two groups of 15 and 20 largemouth bass (Micropterus salmoides Lacepede) were implanted with 400-day radio tags in February 2000 and 2001 to determine changes in movement and behavior before and after hydrilla reduction.(PDF contains 8 pages.)

A Method for siting and prioritizing the removal of derelict vessels in Florida Coastal Waters: test applications in the Florida Keys

Increased boating activities and new waterfront developments have contributed an estimated 3,000 dismantled, abandoned, junked, wrecked, derelict vessels to Florida coastal waters. This report outlines a method of siting and prioritizing derelict vessel removal using the Florida Keys as a test area. The data base was information on 240 vessels, obtained from Florida Marine Patrol files. Vessel location was plotted on 1:250,000 regional and 1:5,000 and 1:12,000 site maps. Type of vessel, length, hull material, engine, fuel tanks, overall condition, afloat and submerged characteristics, and accessibility, were used to derive parametric site indices of removal priority and removal difficulty. Results indicate 59 top priority cases which should be the focus of immediate clean up efforts in the Florida Keys. Half of these cases are rated low to moderate in removal difficulty; the remainder are difficult to remove. Removal difficulty is a surrogate for removal cost: low difficulty -low cost, high difficulty - high cost. The rating scheme offers coastal planners options of focusing removal operations either on (1) specific areas with clusters of high priority derelict vessels or on (2) selected targeted derelicts at various, specific locations. (PDF has 59 pages.)

Effects of the Cessation of Sewage Sludge Dumping at the 12-Mile Site: Proceedings of the 12-Mile Dumpsite Symposium, Ocean Place Hilton Hotel, Long Branch, New Jersey, 18-19 June 1991

This study owes its inception to the wisdom and experience of the staff of the Northeast Fisheries Science Center who, after several decades of surveys in the New York Bight, recognized a unique opportunity to capitalize on the decision to stop ocean dumping of sewage sludge and designed an innovative field study to evaluate effects on living marine resources and their habitats. For decades ocean dumping was viewed as a cheap and effective means for disposal of wastes generated by urbanized coastal areas. Even after the 12-mile site was closed, sewage sludge continued to be dumped at Deepwater Dumpsite 106. The 6-mile site off the NewJersey coast is still used as a dumpsite for dredged material from New York Harbor areas. Discussions continue on the propriety of using the deep ocean spaces for disposal of a variety of material including low level radioactive wastes. Consequently, managers are still faced with critical decisions in this area. It is to be hoped that the results from the 12-mile study will provide the necessary information on which these managers can evaluate future risks associated with ocean waste disposal. (PDF file contains 270 pages.)

Utilization of waste waters in fish production: preliminary results from fish culture studies in floating cages in a sewage pond, New Bussa, Nigeria

The utilization of waste waters in aquaculture were briefly reviewed. At the National Institute for Freshwater Fisheries Research (NIFFR), stocking density (20 to 160 fish/m super(3)) experiments using Sarotherodon galilaeus (without supplementary feeding) in floating cages were carried out in a sewage pond (0.4ha surface area). Cage culture of S. galilaeus was observed to have potentials in waste waters aquaculture. Recommendations were made on the execution of an intergrated waste water management and utilization.

Report on the physical, bacteriological and biochemical analyses of seawater samples collected off existing sewage outfalls in the Sierra Leone River Estuary

The studies reported were undertaken as part of a wide environmental feasibility study for the establishment of a modern sewage system in Freetown. The aim of this part of the study was to determine whether the hydrological regime of the Sierra Leone River Estuary would permit the large-scale introduction of sewage into the estuary without damaging the environment. The important factors were whether: 1) there would be sufficient dilution of the sewage; 2) fleatable particles or other substances would create significant adverse effects in the estuarine ecosystem. The outfall sites are described together with the sampling stations, methods and analyses. Results include: 1) T/S profiles; 2) chemical analysis of the water. A review of literature on the Sierra Leone River Estuary is included which provides information on the plankton, benthos and fisheries. Results suggest that at certain points where local circulations occur it would be inadvisable to locate untreated sewage outfalls. Such points are frequently observed in small embayments. These studies have been of short duration but the data can serve as baseline for more extended investigations which would give a more complete picture of the seasonal patterns in the estuary.

Changes of water quality and sediment phosphorus of a small productive lake following decreased phosphorus loading

Esthwaite Water is the most productive or eutrophic lake in the English Lake District. Since 1945 its water quality has been determined from weekly or biweekly measurements of temperature, oxygen, plant nutrients and phytoplankton abundance. The lake receives phosphorus from its largely lowland-pasture catchment, sewage effluent from the villages of Hawkshead and Near Sawrey, and from a cage-culture fish farm. From 1986 phosphorus has been removed from the sewage effluent of Hawkshead which was considered to contribute between 47% and 67% of the total phosphorus loading to the lake. At the commencement of phosphorus removal regular measurements of phosphorus in the superficial 0-4 cm layer of lake sediment were made from cores collected at random sites. Since 1986 the mean annual concentration of alkali-extractable sediment phosphorus has decreased by 23%. This change is not significant at the 5% level but nearly so. There has been no marked change in water quality over this period. Summer dominance of blue-green algae which arose in the early 1980s after decline of the previous summer forms, Ceratium spp., has been maintained. Improvement in water quality is unlikely to be achieved at the present phosphorus loading.

Analyses of treated sewage effluent from Grasmere Treatment Unit (1974-1976), England [Dataset]

This dataset provides raw data of chemical analyses made during studies on seasonal variations of treated sewage effluent from Grasmere Treatment Unit in Cumbria. Measurements of sodium, calcium, potassium, magnesium and chloride ions were taken between 1974 and 1976.

Removal of Sea Lettuce, Ulva spp., in Estuaries to Improve the Environments for Invertebrates, Fish, Wading Birds, and Eelgrass, Zostera marina

Mats (biomasses) of macroalgae, i.e. Ulva spp., Enteromorpha spp., Graciolaria spp., and Cladophora spp., have increased markedly over the past 50 years, and they cover much larger areas than they once did in many estuaries of the world. The increases are due to large inputs of pollutants, mainly nitrates. During the warm months, the mats lie loosely on shallow sand and mud flats mostly along shorelines. Ulva lactuca overwinters as buds attached to shells and stones, and in the spring it grows as thalli (leaf fronds). Mats eventually form that are several thalli thick. Few macroinvertebrates grow on the upper surfaces of their thalli due to toxins they produce, and few can survive beneath them. The fish, crabs, and wading birds that once used the flats to feed on the macroinvertebrates are denied these feeding grounds. The mats also grow over and kill mollusks and eelgrass, Zostera marina. An experiment was undertaken which showed that two removals of U. lactuca in a summer from a shallow flat in an estuarine cove maintained the bottom almost free of it.

Colton Beck obstruction removal 1953

A worker drilling in Colton Beck,, North West England, UK, trying to make it more accessible for fish passing in 1953. This photo is part of a Photo Album that includes pictures from 1935 to 1954.

Adjustment of ocean color sensor calibration through multi-band statistics

The band-by-band vicarious calibration of on-orbit satellite ocean color instruments, such as SeaWiFS and MODIS, using ground-based measurements has significant residual uncertainties. This paper applies spectral shape and population statistics to tune the calibration of the blue bands against each other to allow examination of the interband calibration and potentially provide an analysis of calibration trends. This adjustment does not require simultaneous matches of ground and satellite observations. The method demonstrates the spectral stability of the SeaWiFS calibration and identifies a drift in the MODIS instrument onboard Aqua that falls within its current calibration uncertainties.

Isolation, purification, and full NMR assignments of cyclopamine from Veratrum californicum

The Hedgehog signaling pathway is essential for embryogenesis and for tissue homeostasis in the adult. However, it may induce malignancies in a number of tissues when constitutively activated, and it may also have a role in other forms of normal and maladaptive growth. Cyclopamine, a naturally occurring steroidal alkaloid, specifically inhibits the Hedgehog pathway by binding directly to Smoothened, an important Hedgehog response element. To use cyclopamine as a tool to explore and/or inhibit the Hedgehog pathway in vivo, a substantial quantity is required, and as a practical matter cyclopamine has been effectively unavailable for usage in animals larger than mice.

Marine fish assemblages associated with fish aggregating devices (FADs): effects of fish removal, FAD size, fouling communities, and prior recruits

Fishes are widely known to aggregate around floating objects, including flotsam and fish aggregating devices (FADs).The numbers and diversity of juvenile fishes that associated with floating objects in the nearshore waters of the eastern tropical Pacific were recording by using FADs as an experimental tool. The effects of fish removal, FAD size, and the presence or absence of a fouling community at the FAD over a period of days, and the presence of prior recruits over a period of hours were evaluated by using a series of experiments. The removal of FAD-associated fish assemblages had a significant effect on the number of the dominant species (Abudefduf troschelii) in the following day’s assemblage compared to FADs where the previous day’s assemblage was undisturbed; there was no experimental effect on combined species totals. Fishes do, however, discriminate among floating objects, forming larger, more species-rich assemblages around large FADs compared to small ones. Fishes also formed larger assemblages around FADs possessing a fouling biota versus FADs without a fouling biota, although this effect was also closely tied to temporal factors. FADs enriched with fish accumulated additional recruits more quickly than FADs that were not enriched with fish and therefore the presence of prior recruits had a strong, positive effect on subsequent recruitment. These results suggest that fish recruitment to floating objects is deliberate rather than haphazard or accidental and they sup-port the hypothesis that flotsam plays a role in the interrelationship between environment and some juvenile fishes. These results are relevant to the use of FADs for fisheries, but emphasize that further research is necessary for applied interests.