537 resultados para 17 m-Lake
Resumo:
Population characteristics of largemouth bass ( Micropterus salmoides L.) including growth, body condition (relative weight), survival, and egg production were examined in relation to abundance of submersed aquatic vegetation (SAV) coverage (primarily hydrilla [ Hydrilla verticillata L.f. Royle]) in three embayments of Lake Seminole, GA, and compared to a previous study conducted in 1998. (PDF has 8 pages.)
Resumo:
Thousands of hectares of native plants and shallow open water habitat have been displaced in Lake Okeechobee’s marsh by the invasive exotic species torpedograss ( Panicum repens L.). The rate of torpedograss expansion, it’s areal distribution and the efficacy of herbicide treatments used to control torpedograss in the lake’s marsh were quantified using aerial color infra red (IR) photography.(PDF has 6 pages.)
Resumo:
Variable watermilfoil (Myriophyllum heterophyllum Michx.) has recently become a problem in Bashan Lake, East Haddam, CT, USA. By 1998, approximately 4 ha of the 110 ha lake was covered with variable watermilfoil. In 1999, the milfoil was spot treated with Aquacide®, an 18% active ingredient of the sodium salt of 2,4-D [(2,4-dichlorophenoxy) acetic acid], applied at a rate of 114 kg/ha. Aquacide® was used because labeling regarding domestic water intakes and irrigation limitations prevented the use of Navigate® or AquaKleen®, a 19% active ingredient of the butoxyethyl ester of 2,4-D. Variable watermilfoil was partially controlled in shallow protected coves but little control occurred in deeper more exposed locations. 2,4-D levels in the treatment sites were lower than desired and offsite dilution was rapid. In 2000, the United States Environmental Protection Agency (USEPA) issued a special local need (SLN) registration to allow the use of Navigate ® or AquaKleen® in lakes with potable and irrigation water intakes. Navigate® was applied at a rate of 227 kg/ha to the same areas as treated in 1999. An additional 2 ha of variable watermilfoil was treated with Navigate® in 2001, and 0.4 ha was treated in mid-September. Dilution of the 2,4-D ester formulation to untreated areas was slower than with the salt formulation. Concentrations of 2,4-D exceeded 1000 μg/ L in several lake water samples in 2000 but not 2001. Nearly all of the treated variable watermilfoil was controlled in both years. The mid-September treatment appeared as effective as the spring and early summer treatments. Testing of homeowner wells in all 3 years found no detectable levels of 2,4-D.(PDF contains 8 pages.)
Resumo:
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.)
Resumo:
From 1997 to 2003, we examined the impacts of two aquatic herbicides, fluridone (Sonar; 1-methyl-3-phenyl-5-[3-(trifluromethl) phenyl]-4(1H)-pyridinone), and dipotassium salt of endothall (Aquathol K; 7-oxabicyclo[2.2.1]heptane-2,3-dicarboxylic acid), used to control dense hydrilla (Hydrilla verticillata L. f. Royle), on population characteristics of juvenile largemouth bass (Micropterus salmoides Lacepede) in small coves (<10 ha) in Lake Seminole, Georgia. In addition, we estimated areal coverage and species composition of submersed aquatic vegetation (SAV) communities in each cove. Fish and plants were sampled in both control (hydrilla infested)and herbicide treated coves in November and March- April each year. Electrofishing catch-per-effort for both number and weight of age-0 and age-1 fish for the 1997 to 2002 year classes was either the same or higher (p < 0.05) in herbicide treated than in control coves. Age-0 fish were larger (p <0.05) in treated, than in control coves in November, but at age-1 in the following spring, fish were slightly longer (p <0.05) in the control coves. Higher age-0 catches were associated with greater percent reductions in numeric catch between age-0 and age-1 and reduced lengths of fish in November indicating density-dependent effects. Age-0 fish lengths were also negatively correlated to percent cover of both total and native SAV. Total or native SAV coverages were not associated with catch-per-unit effort for number and weight, but nearly all control and herbicide treated coves had total SAV coverage greater than 40%. Applications of both Sonar and Aquathol K reduced total SAV coverage and hydrilla, permitted the establishment of native SAVs, and had either neutral or positive impacts on young largemouth bass in small coves in Lake Seminole. (PDF contains 7 pages.)
Resumo:
CONTENTS: BFAR moves on in Region 6, by Janice N. Tronco. Livelihoods initiatives in Sapian Bay, by Tee-Jay A. San Diego. Improving access to information through Barangay Learning Resource Centers, by Elizabeth M. Gonzales. The Philippines Fisheries Information System, by Agnes C. Solis. The contributions of planning activities in the participatory process, by Rommel P. Guarin. Inter-LGU alliance building: a key to sustaining the Integrated Fisheries and Aquatic Resource Management Council (IFARMC), by Josephine P. Savaris.
Resumo:
CONTENTS: What do we need to learn about to understand how people live, by Kath Copley and William Savage. Taking steps to making livelihoods work, by Erwin L. Pador. Reflections on the India-Nepal Workshop, by Rubu Mukherjee and Nilkanth Pokhrel. Reflections on the role of livelihoods approaches and analysis in Lao PDR, by Phanthavong Vongsamphanh and Graham Haylor. After the Workshop on Livelihoods Approaches and Analysis, by Khin Maung Soe, Aye Aye Zaw, Nilar Kyawe and Myant Thar Htun. The relevance of livelihoods approaches in Yunnan, China, by Susan Li and William Savage
Resumo:
CONTENTS: Pasoso project: local livelihoods and turtle conservation in a small island MPA in central Sulawesi, Indonesia, by Abigail Moore. Fisheries development in Lao PDR, by Khamphet Roger. Creating better fisher livelihoods through leasable fisheries, by Khin Maung Soe. The Jankar system for sustainable livelihoods: lessons from the EIRFP, by Binay Kumar Sahay. Alternative livelihoods for landlocked areas in BFAR Region 6, by Jacqueline T. Mamburam. Lessons learned and future replication from Trao reef locally managed marine reserve, by Than Thi Hien.
Resumo:
CONTENTS: Young people taking bolder steps, by Josephine P. Savaris. Providing a venue for voices to be heard, by Elizabeth M. Gonzales and Josephine Savaris. Rehabilitation of Bundu Pond: STREAM’s Initiative and DoF’s Action, by Bhim Nayak and Ashish Kumar. Coastal resources utilization and conservation issues in Cox’s Bazar, Bangladesh, by M.K. Abu Hena, H. Sharifuzzaman, M.S. Aftabuddin and M.N. Haque. People, fish and reefs: a livelihoods learning curve, by Abigail Moore. Understanding the marine ornamental trade and its impact on the livelihoods of poor stakeholders in the Philippines, by Elizabeth M. Gonzales.
Resumo:
CONTENTS: Changes in Jabarrah, by Satyendra D. Tripathi, as told by Thanda Mahato. Palu Hijau in the Banggai Islands Jabarrah: using knowledge for change, by Akhdary Dj Supu, translated by Abigail Moore. Banggai Islands case study: building foundations for action, by Samliok Ndobe, translated by Abigail Moore. Three stories from Nepal, by Ghanshayam Poudel, Suraj, Ramesh Gautam, Pashupati Chaudhary, Anil Subedi, Muralidhar Mishara and Chet Nath Adhikari. Me and my work, by Sheryll Alcazar. Livelihoods approaches: skills learned, applied and shared, by Monica Piquero-Tan.
Resumo:
CONTENTS: Seaweed culture and farmer incomes in Bekasi, Indonesia, by A. Mauksit L. Maala and Aniza Suspita. Significant change for a self-help group, by Nguyen Song Ha. Conflict over fishing in Jharkhand, by Ashish Kumar. Two worlds across a highway, by William Savage. Critical steps in preparing coastal communities for effective policy changes, by Josephine P. Savaris. New guidelines on data collection and iniormation sharing for co-management, by Charlotte Howard.
Resumo:
CONTENTS: First one-stop aqua shop in Pakistan, by Syed Nadeem Sharib and Muhammad Junaid Wattoo. Dad Karim: a fisherman of Gwadar, by Abdul Rahim. Learning to fish in the deep sea of Sindh Province, by Muhammad Alam. Freshwater prawn fishery of Pakistan, by Muhammad Yaqoob. Cephalopod fishery: a local technique to catch cuttlefish in the coastal waters of Pakistan, by Shabir Ali Amir. Grouper culture in Pakistan, by S. Makhdoom Hussain and Zakia Khatoon.
Resumo:
Mechanical weed harvesting has been used to control nuisance vegetation in Lake Keesus since 1979. Fish, turtles, and amphibians often become entangled in the vegetation and are incidentally removed from the lake while harvesting weeds. Mechanical harvesting removed 2 to 8% of the standing crop of juvenile fish in harvested areas in Saratoga Lake, New York (Mikol 1985) and 32% of the fish population in harvested areas in Orange Lake, Florida, representing an estimated replacement value of $6000 per ha (Haller et al. 19890). Engle (1990) found mechanical harvesting removed 21,000 to 31,000 fish per year from Lake Halverson, Wisconsin, representing 25% of the fry in the lake. Little other current information has been published concerning aquatic vertebrate removal by mechanical weed harvesting in Wisconsin, though it is a commonly used management tool. Additionally, only Engle (1990) reported information on the removal of turtles relative to weed harvesting, but none on amphibians. The objective of this study was to document the number, species, and size of vertebrates removed by mechanically harvesting weeds in Lake Keesus.
Resumo:
CA dense mat-forming population of Eurasian watermilfoil ( Myriophyllum spicatum L . ) was interfering with fishing and recreation in a small western Washington lake. A low concentration (1.5 mg/L active ingredient) of the herbicide endothall formulated as Aquathol® K was used in 2000 to attempt to selectively control the Eurasian watermilfoil. Aquatic plant biomass and frequency data were collected before treatment, ten weeks after treatment and during the growing season for 3 additional years. Macrophyte data were analyzed to assess the herbicide’s impacts on Eurasian watermilfoil as well as the rest of the aquatic plant community. Results showed a significant decrease in Eurasian watermilfoil biomass and frequency 10 weeks after treatment. The Eurasian watermilfoil continued to be present, but at a significantly reduced level through the remainder of the study (3 years after treatment). Of the native plant species, large-leaf pondweed ( Potamogeton amplifolius Tucker . ) frequency and biomass was significantly reduced after treatment. Common elodea ( Elodea canadensis Rich.), muskgrass ( Chara sp. Vallaint.) and bladderwort ( Utricularia sp. L.) all increased significantly after treatment. (PDF has 6 pages.)
Resumo:
Giant cutgrass ( Zizaniopsis miliacea (Michx.) Doell. & Asch.), a tall emergent grass native to the southeastern United States, was studied in Lake Seminole where it formed large expanding stands, and Lake Alice where it was confined to a stable narrow fringe.