948 resultados para Coralline algae.
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Podeu consultar l'Informe complet a: http://hdl.handle.net/2445/23662
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Podeu consultar l'Informe complet a: http://hdl.handle.net/2445/23672
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Podeu consultar l'Informe complet a: http://hdl.handle.net/2445/23675
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A total of 42 isopod species from the Strait of Gibraltar and nearby areas were found, including the first record of Munna fabricii, Monodanthura maroccana, Campecopea hirsute, and Natatolana gallica from the Mediterranean; Synisoma nadejda and Uromunna petiti from the Atlantic; and Munna fabricii, Uromunna petiti, Monodanthura maroccana, Stellanthura cryptobia and Natatolana gallica from the Iberian waters. This article includes the previous records from the Iberian waters for all the species. The greatest number of species were found in Tarifa (16 species), located in the transition zone between the Atlantic Ocean and the Mediterranean Sea. According to depth, the distribution of species was as follows: 18 species were collected in the intertidal zone, mostly Dynamene edwardsi and Ischyromene lacazei; 33 species were found between 1 and 10 m, 13 species were found between 11 and 20 m, and 6 species were found between 21 and 28 m, mostly Janira maculosa. According to habitat, 16 species were collected on soft bottoms, 2 species on Zostera, and 22 species on algae substrata, mostly Halopteris, Asparagopsis and Cystoseira. The most diverse genus was Cymodoce (5 species). This paper contributes to the taxonomic, faunistic and biogeographical knowledge of the benthic communities from the Strait of Gibraltar and nearby areas.
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The Antalya nappes (western Taurides-Turkey)*consist of several tectonic units which document the*Southern Neotethyan paleomargin from the Arabo-African*shallow shelf to the oceanic crust.*The Kerner Gorge Units (Upper Antalya nappes)*show a full stratigraphical succession from Ordovician*to Late Cretaceous. A carbonate platform regime*appeared during Late Permian times and existed up*to the early Middle Triassic. For detailed investigations*on the Permo-Triassic boundary, two lithostratigraphic*profiles have been selected: the Curuk*dag and the Kerner Gorge sections.*The main results presented in this paper are : 1) the Late Permian Pamucak Formation (Midian-*Dzhulfian) consists of calcareous algae-foraminiferae*bearing black limestones, locally rich in*brachiopods, crinoids and bryozoae : 2) this black limestone is overlain by an oolitic*grainstone. In the Curuk dag section, the oolitic horizon*is capped by a thin level of calcrete type; emersive*conditions are also inferred by a strong diagenetic*change within the oolitic deposit : 3) the first Early Triassic fossils, appearing*within or above the oolitic grainstone, are microforaminifera*and Pseudoclaraia wangi (late Griesbachian*in age). In the Curuk dag, a rich Early Triassic*microforaminifera association seems linked to a microbiallite*boundstone facies : 4) the overlying unfossiliferous lime mudstone,*the oolitical thick bedded grainstone, the variegated*marly limestone and the vermicular limestone facies*are present. not only in southern Turkey but seem*constant through ' the entire peri arabo-african platform.*Striking similarities appear between the studied*profiles and the Bellerophon-Werfen succession in the*Southern Alps..
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BACKGROUND: Trichoplax adhaerens is the best-known member of the phylum Placozoa, one of the earliest-diverging metazoan phyla. It is a small disk-shaped animal that glides on surfaces in warm oceans to feed on algae. Prior anatomical studies of Trichoplax revealed that it has a simple three-layered organization with four somatic cell types. RESULTS: We reinvestigate the cellular organization of Trichoplax using advanced freezing and microscopy techniques to identify localize and count cells. Six somatic cell types are deployed in stereotyped positions. A thick ventral plate, comprising the majority of the cells, includes ciliated epithelial cells, newly identified lipophil cells packed with large lipid granules, and gland cells. Lipophils project deep into the interior, where they alternate with regularly spaced fiber cells whose branches contact all other cell types, including cells of the dorsal and ventral epithelium. Crystal cells, each containing a birefringent crystal, are arrayed around the rim. Gland cells express several proteins typical of neurosecretory cells, and a subset of them, around the rim, also expresses an FMRFamide-like neuropeptide. CONCLUSIONS: Structural analysis of Trichoplax with significantly improved techniques provides an advance in understanding its cell types and their distributions. We find two previously undetected cell types, lipohil and crystal cells, and an organized body plan in which different cell types are arranged in distinct patterns. The composition of gland cells suggests that they are neurosecretory cells and could control locomotor and feeding behavior.
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The DMACC Lake Watershed Improvement project will focus on water quality and quantity as well as channel and lake restoration. Roadway, parking lot, and roof drainage from the west and northwest portions of the campus add significant amounts of pollutants and silt to the lake. Severe channel erosion exists along the northern creek channel with exposed cut banks ranging from 2-10 feet in height devoid of vegetation. Heavy lake sedimentation and algae blooms are a result of accumulated sediment being conveyed to the lake. Most sections of the north channel have grades of between 0.5% and 1%. This channel receives large scouring flow velocities. There are no natural riffle or pool systems. There are five areas where these riffle and pool systems may need to be created in order to slow overall channel velocities. This will create a series of rock riffles and a still pool that will mimic the conditions that natural channels tend to create, protecting the channel from undercutting. Multiple practices will need to be implemented to address the pollutant, silt, and channel erosion. Improvements will be specifically tailored to address problems observed within the north channel, on-site drainage from the west and northwest, as well as off-site drainage to the north of the campus and east of Ankeny Blvd (Hwy 69). The result will be improved quality and quantity of site drainage and a channel with a more natural appearance and reduced scour velocities. Sections of the north channel will require grading to establish slopes that can support deep rooted vegetation and to improve maintenance access. Areas with eroded banks will require slope pull back and may also require toe armor protection to stabilize. A constructed wetland will collect and treat runoff from the west on site parking lot, before being discharged into the lake. This project will create educational opportunities to both students and the general public as well as interested parties outside of the local area for how an existing system can be retro fitted for improved watershed quality.
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Lake Morris is the larger of two lakes which serve as the municipal water supply for the City of Chariton, Iowa. As a site for fishing and boating, it also serves as a significant recreational resource for area residents. Its ability to sustain these uses has been significantly impaired by long-term and ongoing accumulation of sediment and sediment-borne nutrients from both public and private land within the watershed. This accumulation has resulted in reduced water depth, reduced water-holding capacity, reduced quality of the fishery, increased water turbidity, increased growth of undesirable algae, and increased cost of treating the water for municipal uses. Water quality projects undertaken in the past, notably the Lucas Lakes Project of the 1990s, made important progress in reducing sedimentation from privately-owned land higher in the watershed, but paid little attention to land owned by the City of Chariton immediately surrounding the lakes. A recent reassessment of gully erosion within the watershed shows serious, ongoing erosion on that City-owned land. This project proposes a two-part approach to improving the water quality in Lake Morris. First, we propose that a complement of five SolarBee water circulation devices be installed in Lake Morris to provide near-term and continuing improvements in water quality, by inhibiting cyanobacterial growth and thereby removing the need for treatment of the lakes with copper sulfate. Second, we propose the installation of erosion-control structures on primarily City-owned land surrounding the lake, to provide a major reduction in ongoing sedimentation.
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The North Fork Maquoketa River Headwaters (NFMRH) has been identified as impaired by nutrients, episodic slugs of ammonia and sediment. The NFMRH TMDL plan calls for a "phasing approach" to managing water quality when the origin is non-point source contaminants. This project will address phase 1 using a performance reward program for targeted cooperators to improve environmental index scores using cost-share, EQIP practices and flexible management alternatives. Pre-project assessments suggest that rewards should target refined management of erosion-prone fields and farms with livestock populations, which contribute to the P and N loads responsible for fertilizing filamentous algae blooms that depress dissolved oxygen concentrations in the NFMRH. The Phosphorus Index, Soil Conditioning Index and cornstalk nitrate test will be used by producers to determine effective alternatives, such as no-till planting, to reduce nutrient and sediment delivery. These evironmental indexes will be especially useful for livestock producers in the livestock dense watershed. This project will extend a NRCS-sponsored Conservation Innovation Grant currently offered to producers in the Coffee Creek sub-watershed to a three-year, watershed-wide effort that will be necessary to make significant improvements in environmental management.
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Reproductive morphology of the Mediterranean red alga Kallymenia patens is described for the first time, confirming its position in the genus. K. patens is characterized by a non-procarpic female reproductive apparatus, carpogonial branch systems consisting of supporting cells bearing both three-celled carpogonial branches and subsidiary cells that lack a hypogynous cell and carpogonium; fusion cells develop numerous connecting filaments, and tetrasporangia are scattered over the thallus and are probably cruciately divided. Old fertile spathulate specimens of K. patens are morphologically similar to K. spathulata, but they can be distinguished by the length of spathulated proliferations (up to 0.6 cm and 6 cm, respectively), the length of inner cortical cells (up to 70 and 30 μm, respectively), and the gonimoblast location (in proliferations from the perennial part of the blade and over all the thallus surface, respectively)
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Little River Lake watershed is a 13,305 acre subwatershed of Little River. The 788 acre lake was listed as a 303d impaired water body in 2008 due to elevated turbidity and algae levels. The Decatur SWCD has prioritized water quality protection efforts within the Little River Lake watershed because 1) portions of this watershed has been identified as the primary contributor of sediment and nutrients to Little River Lake, which provides an essential source of drinking water for Decatur County and the Southern Iowa Rural Water Association; 2) the watershed provides exemplary education and project interpretation opportunities due to its proximity to Little River Lake Recreation Area, and 3) by using targeted and proven soil conservation practices to address water quality deficiencies the probability of successfully attenuating soil erosion and ameliorating water quality impairments is enhanced. The specific goals of this proposal are to: 1. reduce annual sediment, and phosphorous delivery to the lake by 11,280 tons and 14,664 lbs., respectively, via applications of conservation practices on targeted agricultural land; 2. delist the lake as an EPA 303d impaired water body via water quality enhancement; 3. obtain a “Full Support” status for the lake’s aquatic life and recreational use; 4. reduce potable water treatment costs (minimum 50% cost reduction) associated with high suspended solid levels; and 5. restore a viable sport-fish population, thereby bolstering tourism and the economy. To achieve timely project implementation the Decatur SWCD has cooperated with the IDNR Watershed Improvement Section, Fisheries Bureau, and IDALS-DSC to assess extant water quality and watershed conditions, coalesced a diverse team of committed partners and secured matching funding from multiple sources.
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The Tuttle Lake Watershed is approximately 125,000 acres and Tuttle Lake itself is 2,270 acres; 5,609 acres of the watershed lies in Iowa territory within Emmet County. It is a sub-watershed of the larger East Fork Des Moines River Watershed, also referred to as Hydrologic Unit Code 07100003. For the purpose of this document, grant money is only being applied for the project implementation in the Iowa portion of the Tuttle Lake Watershed. Tuttle Lake was placed on the 2002 EPA 303(d) Impaired Waters List due to a “very large population of suspended algae and very high levels of inorganic turbidity.” In 2004, the Iowa Department of Natural Resources (IDNR) completed a Total Maximum Daily Load (TMDL) study on Tuttle Lake and found excess sediment and phosphorus levels being the primary pollutants causing the algae and turbidity impairment. Although two point sources were located in Minnesota, IDNR determined that the influx of nutrients is likely from agricultural runoff and re-suspension of lake sediment. The condition of Tuttle Lake is such that the reduction of sediment, nutrients [phosphorus and nitrogen] and pathogens is the primary objective. To achieve that objective, wetlands will be constructed in this first phase to reduce the delivery of nitrogen, phosphorus, and sediment to Tuttle Lake.