9 resultados para Lamprey

em Aquatic Commons


Relevância:

20.00% 20.00%

Publicador:

Resumo:

Population pressure in coastal New Hampshire challenges land use decision-making and threatens the ecological health and functioning of Great Bay, an estuary designated as both a NOAA National Estuarine Research Reserve and an EPA National Estuary Program site. Regional population in the seacoast has quadrupled in four decades resulting in sprawl, increased impervious surface cover and larger lot rural development (Zankel, et.al., 2006). All of Great Bay’s contributing watersheds face these challenges, resulting in calls for strategies addressing growth, development and land use planning. The communities within the Lamprey River watershed comprise this case study. Do these towns communicate upstream and downstream when making land use decisions? Are cumulative effects considered while debating development? Do town land use groups consider the Bay or the coasts in their decision-making? This presentation, a follow-up from the TCS 2008 conference and a completed dissertation, will discuss a novel social science approach to analyze and understand the social landscape of land use decision-making in the towns of the Lamprey River watershed. The methods include semi-structured interviews with GIS based maps in a grounded theory analytical strategy. The discussion will include key findings, opportunities and challenges in moving towards a watershed approach for land use planning. This presentation reviews the results of the case study and developed methodology, which can be used in watersheds elsewhere to map out the potential for moving towns towards EBM and watershed-scaled, land use planning. (PDF contains 4 pages)

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Histochemical experiments are conducted in order to study the interrenal cells of European brook lamprey (Lampetra planeri).

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The life cycle of the river lamprey, L. fluviatilis, is reviewed. The larval lamprey, or ammocoete, is a blind, filter-feeding animal, which normally lies concealed in the silt deposits of streams and rivers. After a period of 3-5 years in fresh water the ammocoete undergoes a metamorphosis in the summer months into a sexually immature, non-feeding stage known as the macrophthalia, which is active. This stage migrates downstream in late winter. It adopts a parasitic existence, in intertidal areas. After 18 months it returns to spawn in fresh water, after a final freshwater stage lasting up to 9 months. The river lamprey dies within a few days after the spawning period of 3-4 weeks, and none survive to spawn the following year.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

This article describes the streams of this unique area of Britain and reviews the published and some unpublished information that is currently available. None of the rivers in the New Forest are more than 30 km long. Many reaches have been artificially straightened, channelized and regraded since the 1840's. The stream waters are typically base-poor, with low nutrient concentrations. Primary productivity and standing crops of algae are predictably low when compared with other streams carrying higher concentrations of minerals and nutrients. The earliest records on the macroinvertebrate fauna go back to the late 19th Century. By 1940, over 20 species of Trichoptera and 10 species of Plecoptera had been recorded, but only four species of Ephemeroptera. Twenty species of fish occur in the streams of the New Forest of which the most common are brown trout, minnow, bullhead, stone loach, brook lamprey and eel.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Histochemical experiments are conducted in order to study the interrenal cells of European brook lamprey (Lampetra planeri).

Relevância:

10.00% 10.00%

Publicador:

Resumo:

We described the diet of the eastern stock of Steller sea lions (Eumetopias jubatus) from 1416 scat samples collected from five sites in Oregon and northern California from 1986 through 2007. A total of 47 prey types from 30 families were identified. The most common prey was Pacific hake (Merluccius productus), followed by salmonids (Oncorhynchus spp.), skates (Rajidae), Pacific lamprey (Lampetra tridentata), herrings (Clupeidae), rockfish (Sebastes spp.), and northern anchovy (Engraulis mordax). Steller sea lion diet composition varied seasonally, annually, and spatially. Hake and salmonids were the most commonly identified prey in scats collected during the summer (breeding season), whereas hake and skate were most common in the nonbreeding season. Continued research on Steller sea lion diet and foraging behavior in the southern extent of their range is necessary to address issues such as climate change, interaction with competing California sea lions, and predation impacts on valuable or sensitive fish stocks.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

This is the Gunnislake Fish Counter Annual Report 2002 from the Environment Agency South West Region, which was held on March 2002. It presents the daily upstream counts of migratory salmonids recorded on the River Tamar at Gunnislake Weir fish counting station in 2002. The data within this report covers the period of the commercial migratory salmonid net buy-back scheme and the National Spring Salmon Bylaws. The report contains section on Net Buy-Back; Species Apportionment; Validation of counter efficiency; results as total number of migratory salmonid (salmon and Sea Trout) counted moving upstream in 2002 at Gunnislake; video validation and Counter Efficiency; and Discussion. The section Discussion includes Salmon and Sea Trout counts recorded on the River Tamar 1995-2002, other fish species observed as sea lamprey and Environmental Factors (river flows, water temperature, and barometric pressure).

Relevância:

10.00% 10.00%

Publicador:

Resumo:

This is the Species management in aquatic Habitats WRc Interim 1997 document produced by the Environment Agency in 1997. This document reports progress on R&D Project 640, which aims to provide information on species of conservation value of particular relevance to the Environment Agency, in relation to its activities affecting aquatic environments. A range of stand-alone outputs is being produced, comprising Species Action Plans, practical management guidelines for Agency staff and third parties, and various research outputs to improve the knowledge base on the status and ecological requirements of priority species. The species of conservation values are: water shrew, daubenton’s bat, Kingfisher, yellow wagtail, Grey wagtail, sand martin, reed bunting, dipper, marsh warbler, great crested new, spined loach, brook lamprey, river lamprey, sea lamprey, shining rams-horn snail, little whirlpool rams-horn snail, depressed river mussel, a freshwater pea mussel, native crayfish, and triangular club-rush. The process of species selection was altered during the course of the project by the report on biodiversity by the UK Biodiversity Steering Group (1995). Whilst still including species that were not particularly endangered but were greatly influenced by the activities of the Agency, the project addressed species on the ‘short’ and ‘middle’ priority lists of the Biodiversity report, particularly those for which the Agency had specific responsibilities.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

This is the River Avon (including Glazebrook) fisheries survey 1978 report produced by South West Water Authority in 1978. This report aims to determine the penetration of Salmon into the River Avon system and to a lesser degree estimate the population of resident salmonids and other indigenous species. Six sections were electro fished at accessible points as detailed below. All fish were identified and measured. Each section was fished through three times to take the majority of the resident species. Small specimens of salmonid fry, eels and lamprey were common in almost all River Avon sections with the exception of Shipley bridge and Avon Dam but due to the mesh size of the standard dip nets used, many slipped through making accurate number estimation impossible.