The Aquatic Commons is a thematic digital repository covering the natural marine, estuarine /brackish and fresh water environments . It includes all aspects of the science, technology, management and conservation of these environments, their organisms and resources, and the economic, sociological and legal aspects.
Subject = Conservation
Mostrando recursos 61 - 80 de 995
News from Academy Bay
Presidential visit. The extraordinary El nino year. The last of the Norwegians. Visits and events at the Darwin Research Station.
The cost of quinine Cinchona pubescens control on Santa Cruz Island, Galapagos - Buddenhagen, Chris; Yanez, Patricio
We analyse the cost of controlling the invasive quinine tree Cinchona pubescens Vahl in the highlands of Santa Cruz Island, Galapagos. Control costs in ten 400 m2 plots formed the basis for estimating the cost of control over the whole island. In the plots, densities were 2100–24,000 stems/ha (stems >150 cm tall) and 55,000–138,000 stems/ha (all size classes combined). Control involved uprooting small plants, and applying of a mix of metsulfuron methyl and picloram to
cut stumps or to machete cuts in the bark of larger trees. These methods are presently used by Galapagos National
Park field crews to control quinine. Costs...
Local distribution patterns of Opuntia echios echios, Bursera graveolens and Scalesia crockeri on Santa Cruz Island, Galapagos - Runkle, James R.; Runkle, William A.
We mapped stems of three plant species in a 2.36 ha plot in the arid zone near the coast of eastern Santa Cruz Island,
Galapagos, Ecuador, to determine factors influencing their local distribution. The three species were Opuntia echios var. echios (Cactaceae), a large cactus, Bursera graveolens (Burseraceae), a small tree that dominates dry woodland near the coast, and the shrub Scalesia crockeri (Asteraceae). In our plot, Opuntia was most abundant near the coast, while Bursera and Scalesia increased in density inland and with increased relief. Scalesia also increased in density with increases in Bursera and decreases in other woody plants...
Arthropods in the Charles Darwin Research Station herbarium,
Galapagos, during 1999–20 - Jaramillo, Patricia; Reyes, Diego; Yanez, Patricio
This paper describes the arthropods found in the Charles Darwin Research Station herbarium from 1999 to 2001.
Nineteen species were found from four classes. Most individuals were from the families Formicidae (Paratrechina
longicornis with 777 individuals), Porcellidae (134), Drosophilidae (43) and Corinnidae (38). CDF Contribution Number 1011.
Viability of seeds in food products proposed for field trips in Galapagos - Jaramillo, Patricia; Bassantes, Joselyn; Tye, Alan
Seeds of 14 plant species extracted from food products proposed for field trips in Galapagos were tested for viability.
Strawberry Fragaria ananasa and Blackberry Rubus glaucus jams (Snob and Gustadina brands) contained no viable
seeds. Schullo brand granola contained inviable Sesame Sesamum indicum seed, but Sesame in granolas prepared in
Galapagos was viable. Sesame seed in bread was viable but Flax Linum usitatissimum seed in bread was not. Brown Rice
Oryza sativa and Sunflower seeds Helianthus annuus were both viable. Fresh Apple Malus domestica, Naranjilla Solanum
quitoense, Cucumber Cucumis sativus, Pineapple Ananas comosus, Pear Pyrus communis, Bell Pepper Capsicum annuum,
Tomato Solanum lycopersicum, Grape Vinis vinifera...
Structure and development of a Scalesia pedunculata stand in the Galapagos Islands - Runkle, James R.; Runkle, William A.
Stands of Scalesia pedunculata in the Galapagos Islands often develop as single-aged cohorts following episodes of mass death and regeneration. We updated earlier studies on a stand that had regenerated soon after the 1982–3 El Niño
event. We quantified stem size distribution and dispersion pattern in a 0.56 ha plot near Los Gemelos on Santa Cruz
Island. The plot was dominated (95% of basal area) by S. pedunculata. The stem size distribution showed the increased
mean and variance for diameter (since 1987 and 1991) expected of an aging stand. Stems averaged smaller than in
1981, just before the last mass mortality episode. Large S....
News from Academy Bay - Tye, Alan; Loose, Ana Maria; Wiedenfeld, David; Key, Gillian; Causton, Charlotte; Cruz, Felipe; Carrion, Victor; Banks, Stuart; Hearn, Alex; Altamirano, Manfred
CDRS Research Highlights, 2004. Plants. Social Sciences. Vertebrates. Invasive Species Total Control Plan. Terrestrial Invertebrates. Project Isabela. Marine Sciences.
Diet of Bottlenose Dolphins Tursiops truncatus in the Northwest Panhandle and Foraging Behavior Near Savannah, Georgia - Bowen, Sabrina Rose
The foraging ecology of bottlenose dolphins Tursiops truncatus in the Northwest Florida Panhandle and estuaries in northern Georgia was determined using diet analysis
and behavioral surveys. Stomach content analysis was completed on bottlenose dolphins(N = 25) that stranded in the Northwest Florida Panhandle from November 2006 to
March 2009. The most abundant prey species were spot Leiostomus xanthurus (20.4%), squid (10.9%), pinfish Lagodon rhombiodes (10.3%), and Atlantic croaker
Micropogonias undulatus (8.5%). Dolphins that stranded during months with a red tide Karenia brevis bloom consumed more pinfish, and spot; whereas dolphins that stranded
in non-bloom months consumed more squid, Atlantic croaker, and silver perch Bairdiella...
Artificial Habitats for Fisheries Enhancement in the Australian Region - Pollard , D. A.
This paper outlines developments over about 20 years in the construction of and ecological research on artificial reefs, fish aggregation devices (FAD's), and other artificial habitats designed to enhance fish populations and fisheries in the Australian region (including New Zealand and Papua New Guinea). Work was initially carried out on multicomponent reefs using a variety of waste materials, as well as some specially constructed concrete and steel structures. Later studies concentrated on single-component reefs, again mainly using waste materials. Although no definitive conclusions were reached on the relative effectiveness of the different materials used, waste motor vehicle tires and derelict...
The Status of Loggerhead, Caretta caretta; Kemp's Ridley, Lepidochelys kempi; and Green, Chelonia mydas, Sea Turtles in U.S. Waters: A Reconsideration - Dodd, Jr. , C. Kenneth; Byles, Richard
Assessing the status of widely distributed marine species can prove difficult because virtually every sampling technique has assumptions, limitations, and biases that affect the results of the study. These biases often are overlooked when the biological and nonbiological implications of the results are discussed. In a recent review, Thompson (1988) used mostly unpublished population census data derived from studies conducted by the National Marine Fisheries Service (NMFS) to draw conclusions about the status of Kemp's ridley, Lepidochelys kempi; Atlantic coast green turtles, Chelonia mydas; and the loggerhead sea turtle, Caretta caretta.
The Great Whales: History and Status of Six Species
Listed as Endangered Under the U.S. Endangered Species Act of 1973 - Perry , Simona L.; DeMaster, Douglas P.; Silber , Gregory K.
In the history of whaling from prehistoric to modern times, the large whales, sometimes called the “great whales,” were hunted most heavily owing in part to their corresponding value in oil, meat, and baleen. Regional populations of North Atlantic right whales, Eubalaena glacialis glacialis, were already decimated by 1700, and the North Atlantic gray whale, Eschrichtius robustus, was hunted to extinction by
the early 1700’s (Mitchell and Mead1).
Effects of the Santa Barbara, Calif., Oil Spill on the
Apparent Abundance of Pelagic Fishery Resources - Squire, Jr. , James L.
Many studies have been made of the effects of oil on marine invertebrates, plants (marine algae and phytoplankton), and vertebrates such as seabirds and marine mammals. An excellent review of these findings, which includes some references to fish and pathological effects of aromatic hydrocarbons, has been published by the Royal Society, London (Clark, 1982). That review dealt with the environmental effects of such major oil spills or releases such as those by the tankers Torry Canyon (119,000 t) on the south coast of England, Metula (50-56,000 t) in the Straits of Magellan, Argo Merchant (26,000 t) off Cape Cod, and...
Differences in Dolphin Mortality Rates in Night and Day Sets for the U.S. Eastern Tropical Pacific Tuna Purse Seine Fishery - Coan, Jr. , Atilio L.; Wallace, Kenneth E.; Jackson , Alan R.
Because dolphins sometimes travel with yellowfin tuna, Thunnus albacares, in the eastern tropical Pacific (ETP), purse seiners use the dolphins to locate and capture tuna schools. During the process of setting the purse seine nets, dolphins often become entangled and drown before they can be released. Data for the U.S. purse seine fleet in the ETP during 1979-88 show that dolphin mortality rates in sets made during the night are higher than mortality rates in sets made during the day. Even with efforts to reduce nightset mortality rates through the use of high intensity floodlights, night set mortality rates remain...
The National Marine Fisheries Service Habitat Conservation
Efforts in Louisiana, 1980 Through 1990 - Hartman, Richard D.; Ruebsamen, Rickey N.; Jones, Peggy M.; Koellen, Jan L.
Data quantifying various aspects of the Corps of Engineers wetland regulatory program in Louisiana from 1980 through 1990 are presented. The National Marine Fisheries Service (NMFS) habitat conservation efforts for this time period are described and averages involved delineated. From 1980 through 1990, NMFS reviewed 14,259 public notices to dredge, fill, or impound wetlands in Louisiana and provided recommendations to the Corps on 962 projects which proposed to impact over 600,000 acres of tidally influenced wetlands. NMFS recommended that impacts to about 279,000 acres be avoided and that more than 150,000 acres of compensatory mitigation be provided. During this period,...
Sea Turtle Observations at Explosive Removals of Energy Structures - Gitschlag, Gregg R.; Herczeg, Bryan A.
Observers were placed at offshore sites to monitor and protect sea turtles during explosive removals of oil and gas structures in the Gulf of Mexico off Louisiana and Texas. Data collected during more than 6,500 hours of monitoring at 106 structure removals in 1992 provided information on sea turtle distribution. Eighteen individuals were observed including 10 loggerheads, 2 leatherbacks, 1 hawksbill, and 5 unidentified sea turtles. The observation rate (individuals per monitoring hour) of sea turtles was about 30 times higher during aerial surveys than during day or night suiface surveys.
Trawling Operations and South African (Cape) Fur Seals, Arctocephalus pusillus pusillus - Wickens, Patti A.; Sims, Peter F.
South African (Cape) fur seals, Arctocephalus pusillus pusillus, interact with the South African trawl fisheries-offshore demersal, inshore demersal, and midwater fisheries. These interactions take thef ollowing forms: Seals take or damage netted fish, on particular vessels they become caught in the propeller, seals drown in the nets, live seals come aboard and may be killed. Except in specific cases of seals damaging particular trawler propellers, interactions result in little cost to the offshore and midwater trawl fisheries. For the inshore fishery, seals damage fish in the net at an estimated cost in excess of R69, 728 (US$18,827) per year, but...