188 resultados para ORGANISMS
Resumo:
Davidson Seamount is one of the largest seamounts in U.S. waters and the first to be characterized as a “seamount.” In 2002 and 2006, the Monterey Bay National Marine Sanctuary (MBNMS) led two multi-institutional expeditions to characterize the geology and natural history of Davidson Seamount. Results from these expeditions to Davidson Seamount are adding to the scientific knowledge of seamounts, including the discovery of new species. In November 2008, the MBNMS boundary was expanded to include the Davidson Seamount. In addition, a management plan for Davidson Seamount was created to develop resource protection, education, and research strategies for the area. The purpose of this taxonomic guide is to create an inventory of benthic and mid-water organisms observed at the Davidson Seamount to provide a baseline taxonomic characterization. At least 237 taxa were observed and are presented in this guide; including 15 new or undescribed species (8 sponges, 3 corals, 1 ctenophore, 1 nudibranch, 1 polychaete, 1 tunicate) recently or currently being described by taxonomic experts. This is the first taxonomic guide to Davidson Seamount, and is intended to be revised in the future as we learn more about the seamount and the organisms that live there. (PDF has 145 pages.)
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Executive Summary: Tropical marine ecosystems in the Caribbean region are inextricably linked through the movement of pollutants, nutrients, diseases, and other stressors, which threaten to further degrade coral reef communities. The magnitude of change that is occurring within the region is considerable, and solutions will require investigating pros and cons of networks of marine protected areas (MPAs), cooperation of neighboring countries, improved understanding of how external stressors degrade local marine resources, and ameliorating those stressors. Connectivity can be broadly defined as the exchange of materials (e.g., nutrients and pollutants), organisms, and genes and can be divided into: 1) genetic or evolutionary connectivity that concerns the exchange of organisms and genes, 2) demographic connectivity, which is the exchange of individuals among local groups, and 3) oceanographic connectivity, which includes flow of materials and circulation patterns and variability that underpin much of all these exchanges. Presently, we understand little about connectivity at specific locations beyond model outputs, and yet we must manage MPAs with connectivity in mind. A key to successful MPA management is how to most effectively work with scientists to acquire the information managers need. Oceanography connectivity is poorly understood, and even less is known about the shape of the dispersal curve for most species. Dispersal kernels differ for various systems, species, and life histories and are likely highly variable in space and time. Furthermore, the implications of different dispersal kernels on population dynamics and management of species is unknown. However, small dispersal kernels are the norm - not the exception. Linking patterns of dispersal to management options is difficult given the present state of knowledge. The behavioral component of larval dispersal has a major impact on where larvae settle. Individual larval behavior and life history details are required to produce meaningful simulations of population connectivity. Biological inputs are critical determinants of dispersal outcomes beyond what can be gleaned from models of passive dispersal. There is considerable temporal and spatial variation to connectivity patterns. New models are increasingly being developed, but these must be validated to understand upstream-downstream neighborhoods, dispersal corridors, stepping stones, and source/sink dynamics. At present, models are mainly useful for providing generalities and generating hypotheses. Low-technology approaches such as drifter vials and oceanographic drogues are useful, affordable options for understanding local connectivity. The “silver bullet” approach to MPA design may not be possible for several reasons. Genetic connectivity studies reveal divergent population genetic structures despite similar larval life histories. Historical stochasticity in reproduction and/or recruitment likely has important, longlasting consequences on present day genetic structure. (PDF has 200 pages.)
Resumo:
Understanding how well National Marine Sanctuaries and other marine protected areas represent the diversity of species present within and among the biogeographic regions where they occur is essential for assessing their conservation value and identifying gaps in the protection of biological diversity. One of the first steps in any such assessment should be the development of clearly defined and scientifically justified planning boundaries representing distinct oceanographic conditions and faunal assemblages. Here, we propose a set of boundaries for the continental shelf of northeastern North America defined by subdivisions of the Eastern Temperate Province, based on a review and synthesis (i.e. meta-analysis) of the scientific literature. According to this review, the Eastern Temperate Province is generally divided into the Acadian and Virginian Subprovinces. Broad agreement places the Scotian Shelf, Gulf of Maine, and Bay of Fundy within the Acadian Subprovince. The proper association of Georges Bank is less clear; some investigators consider it part of the Acadian and others part of the Virginian. Disparate perspectives emerge from the analysis of different groups of organisms. Further, while some studies suggest a distinction between the Southern New England shelf and the rest of the Mid-Atlantic Bight, others describe the region as a broad transition zone with no unique characteristics of its own. We suggest there exists sufficient evidence to consider the Scotian Shelf, Gulf of Maine, Georges Bank, Southern New England, and Southern Mid-Atlantic Bight as distinct biogeographic regions from a conservation planning perspective, and present a set of proposed mapped boundaries. (PDF contains 23 pages.)
Resumo:
The implementation of various types of marine protected areas is one of several management tools available for conserving representative examples of the biological diversity within marine ecosystems in general and National Marine Sanctuaries in particular. However, deciding where and how many sites to establish within a given area is frequently hampered by incomplete knowledge of the distribution of organisms and an understanding of the potential tradeoffs that would allow planners to address frequently competing interests in an objective manner. Fortunately, this is beginning to change. Recent studies on the continental shelf of the northeastern United States suggest that substrate and water mass characteristics are highly correlated with the composition of benthic communities and may therefore, serve as proxies for the distribution of biological biodiversity. A detailed geo-referenced interpretative map of major sediment types within Stellwagen Bank National Marine Sanctuary (SBNMS) has recently been developed, and computer-aided decision support tools have reached new levels of sophistication. We demonstrate the use of simulated annealing, a type of mathematical optimization, to identify suites of potential conservation sites within SBNMS that equally represent 1) all major sediment types and 2) derived habitat types based on both sediment and depth in the smallest amount of space. The Sanctuary was divided into 3610 0.5 min2 sampling units. Simulations incorporated constraints on the physical dispersion of sampling units to varying degrees such that solutions included between one and four site clusters. Target representation goals were set at 5, 10, 15, 20, and 25 percent of each sediment type, and 10 and 20 percent of each habitat type. Simulations consisted of 100 runs, from which we identified the best solution (i.e., smallest total area) and four nearoptimal alternates. We also plotted total instances in which each sampling unit occurred in solution sets of the 100 runs as a means of gauging the variety of spatial configurations available under each scenario. Results suggested that the total combined area needed to represent each of the sediment types in equal proportions was equal to the percent representation level sought. Slightly larger areas were required to represent all habitat types at the same representation levels. Total boundary length increased in direct proportion to the number of sites at all levels of representation for simulations involving sediment and habitat classes, but increased more rapidly with number of sites at higher representation levels. There were a large number of alternate spatial configurations at all representation levels, although generally fewer among one and two versus three- and four-site solutions. These differences were less pronounced among simulations targeting habitat representation, suggesting that a similar degree of flexibility is inherent in the spatial arrangement of potential protected area systems containing one versus several sites for similar levels of habitat representation. We attribute these results to the distribution of sediment and depth zones within the Sanctuary, and to the fact that even levels of representation were sought in each scenario. (PDF contains 33 pages.)
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One goal of Gray’s Reef National Marine Sanctuary (NMS) is to protect the unique community found within the Sanctuary’s boundaries. An understanding of the ecological interactions, including trophic structure, among these organisms is necessary to realize this goal. Therefore, diet information for 184 fish species was summarized from 113 published studies. Among the fish included are 84 fish species currently known to reside in Gray’s Reef NMS. The locations of these studies ranged from the Atlantic Ocean off the coast of the northeast United States to northern Brazil, the Gulf of Mexico, and the Caribbean. All of the species described in this bibliography occur in the southeast United States and are, therefore, current or potential residents of Gray’s Reef National Marine Sanctuary. Each entry includes the objectives, brief methods, and conclusions of the article. The bibliography is also indexed by species. (PDF contains 64 pages.)
Resumo:
Although ambient (background) noise in the ocean is a topic that has been widely studied since pre-World War II, the effects of noise on marine organisms has only been a focus of concern for the last 25 years. The main point of concern has been the potential of noise to affect the health and behavior of marine mammals. The Stellwagen Bank National Marine Sanctuary (SBNMS) is a site where the degradation of habitat due to increasing noise levels is a concern because it is a feeding ground and summer haven for numerous species of marine mammals. Ambient noise in the ocean is defined as “the part of the total noise background observed with an omnidirectional hydrophone.” It is an inherent characteristic of the medium having no specific point source. Ambient noise is comprised of a number of components that contribute to the “noise level” in varying degrees depending on where the noise is being measured. This report describes the current understanding of ambient noise and existing levels in the Stellwagen Bank National Marine Sanctuary. (PDF contains 32 pages.)
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Marine reserves, often referred to as no-take MPAs, are defined as areas within which human activities that can result in the removal or alteration of biotic and abiotic components of an ecosystem are prohibited or greatly restricted (NRC 2001). Activities typically curtailed within a marine reserve are extraction of organisms (e.g., commercial and recreational fishing, kelp harvesting, commercial collecting), mariculture, and those activities that can alter oceanographic or geologic attributes of the habitat (e.g., mining, shore-based industrial-related intake and discharges of seawater and effluent). Usually, marine reserves are established to conserve biodiversity or enhance nearby fishery resources. Thus, goals and objectives of marine reserves can be inferred, even if they are not specifically articulated at the time of reserve formation. In this report, we review information about the effectiveness of the three marine reserves in the Monterey Bay National Marine Sanctuary (Hopkins Marine Life Refuge, Point Lobos Ecological Reserve, Big Creek Ecological Reserve), and the one in the Channel Islands National Marine Sanctuary (the natural area on the north side of East Anacapa Island). Our efforts to objectively evaluate reserves in Central California relative to reserve theory were greatly hampered for four primary reasons; (1) few of the existing marine reserves were created with clearly articulated goals or objectives, (2) relatively few studies of the ecological consequences of existing reserves have been conducted, (3) no studies to date encompass the spatial and temporal scope needed to identify ecosystem-wide effects of reserve protection, and (4) there are almost no studies that describe the social and economic consequences of existing reserves. To overcome these obstacles, we used several methods to evaluate the effectiveness of subtidal marine reserves in Central California. We first conducted a literature review to find out what research has been conducted in all marine reserves in Central California (Appendix 1). We then reviewed the scientific literature that relates to marine reserve theory to help define criteria to use as benchmarks for evaluation. A recent National Research Council (2001) report summarized expected reserve benefits and provided the criteria we used for evaluation of effectiveness. The next step was to identify the research projects in this region that collected information in a way that enabled us to evaluate reserve theory relative to marine reserves in Central California. Chapters 1-4 in this report provide summaries of those research projects. Contained within these chapters are evaluations of reserve effectiveness for meeting specific objectives. As few studies exist that pertain to reserve theory in Central California, we reviewed studies of marine reserves in other temperate and tropical ecosystems to determine if there were lessons to be learned from other parts of the world (Chapter 5). We also included a discussion of social and economic considerations germane to the public policy decision-making processes associated with marine reserves (Chapter 6). After reviewing all of these resources, we provided a summary of the ecological benefits that could be expected from existing reserves in Central California. The summary is presented in Part II of this report. (PDF contains 133 pages.)
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ENGLISH: The purpose of this study was to investigate the possibility that certain species of Chaetognatha found in Eastern Tropical Pacific waters can serve as biological indicators of oceanographic features. "Indicator" organisms have been found useful in identifying water types, in tracing the pattern of current systems, and in tracing the origin of moving water masses. To be of use in this type of study, the organisms must be sufficiently abundant to be readily sampled, and easily identified to species; they must also, at least partially, fulfill the additional requisites listed and discussed by Sverdrup, Johnson, and Fleming (1942, pp. 866-867). Among several groups of organisms fulfilling these requirements are the Chaetognatha. Specimens of this group of animals occurred in large numbers in the plankton samples used for this study. The works of Thomson (1947), Fraser (1942), Ritter-Zahony (1911), and Sund (1959) were used for identification. SPANISH: El objetivo de este estudio ha sido el de investigar la posibilidad de utilizar ciertas especies de quetognatos encontrados en el Pacífico Oriental Tropical como indicadoras biológicas de características oceanográficas. Organismos "indicadores" fueron encontrados útiles para la identificación de tipos de agua, el trazado del régimen de los sistemas de corrientes y la determinación del origen de masas de agua en movimiento. Para servir a este tipo de estudios, los organismos deben ser lo suficientemente abundantes como para ser fácilmente muestreados e identificados hasta la especie; también deben satisfacer, por lo menos parcialmente, los requerimientos indicados y discutidos par Sverdrup, Johnson y Fleming (1942, pags. 866-867).
Resumo:
The endosymbiosis of algae with invertebrates may be viewed with at least two major orientations. On the one hand, one may focus on the plant and animal as essentially separate organisms living together, as the word symbiosis states. The products which are exchanged between the plant and animal and the effects of the association on either partner are then of particular interest. On the other hand, one may consider the partnership as an entity, and attempt to investigate the physiology, behavior, etc. of the symbiotic association, observing what differences may appear between the "plant-animal" and analogous non-symbiotic organisms. It is the second approach which I have tried to take in this thesis. I have concentrated on some effects of light on symbiotic and aposymbiotic sea anemones of the species Anthopleura elegantissima, particularly with respect to pigmentation and several types of behavior.
Resumo:
ENGLISH: Knowledge of the kinds of organisms eaten by tunas, and the relative importance of different kinds of organisms in different situations, is of importance to our understanding of regional and local aggregations and of the behavior of the tropical tunas. Determination of the relative importance of benthic forms in the stomachs of tunas captured in the vicinity of islands and offshore banks, compared with the forms found in the stomachs of those from oceanic areas, distant from these shoal areas, is useful to the understanding of the mechanisms by which the islands and banks attract tuna. A thorough knowledge of the diet may also reveal more about the seasonal and annual variations in the distribution of these fish along the coasts of Mexico, Central America and elsewhere. A knowledge of the diet of the tunas is basic to quantitative studies of the zooplankton and nekton in the Eastern Pacific Ocean with reference to the production of tunas. Studies of the diet of the tropical tunas by examination of stomach contents was, therefore, commenced in late 1957. SPANISH: El conocimiento de las clases de organismos de que se alimentan los atunes, y la importancia relativa de las diferentes clases de organismos en situaciones diferentes, es de valor para nuestra comprensión de las agrupaciones regionales y locales, y de los hábitos de los atunes tropicales. La determinación de la importancia relativa de las formas bénticas en los estómagos de los atunes capturados en la vecindad de las islas y de los bancos apartados de la costa, comparadas con las formas encontradas en los estómagos de los atunes procedentes de áreas oceánicas, distantes de estas áreas poco profundas, es útil para comprender el mecanismo por el cual las islas y los bancos atraen al atún. Un conocimiento completo de la dieta puede revelar también algo más acerca de las variaciones estacionales y anuales en la distribución de estos peces a lo largo de las costas de México, América Central y otras partes. El conocimiento de la dieta del atún es básico para los estudios cuantitativos del zooplancton y del necton en el Océano Pacífico Oriental, con referencia a la producción de los atunes. El estudio de la dieta de los atunes tropicales mediante el examen del contenido estomacal, fué comenzado, por lo tanto, a fines de 1957.
Resumo:
ENGLISH:The gill rakers of both juvenile and adult anchovetas are long and numerous, with many fine processes which make a very efficient straining apparatus. The stomach is modified into a gizzard. The intestine undergoes heteronomous growth, and attains about eight times the standard length in adults. The stomach contents of 39 samples of juvenile fish and 120 adult fish were examined. Diatoms were the principal food of all the sizes of fish examined, from 29 to 153 millimeters. Silicoflagellates, dinoflagellates, pollen grains, formaniferans, rotifer shells, crustaceans, and eggs, probably of crustaceans, were also found in small amounts. Coscinodiscus, a diatom, was the most important item found in the stomachs of the juvenile fish. No strong differences were observed in the feeding habits of different sizes of juveniles. Even taking into account their smaller size, the juveniles had smaller volumes of material and lesser numbers of organisms in their stomachs than did the adults. The stomachs of the adult fish, unlike those of the juveniles, usually contained considerable quantities of mud. Melosira, Coscinodiscus, and Thalassionema, all diatoms, were the most important organisms found in the stomachs of the adults. The incidence of Melosira was much higher in the stomachs of fish from the areas to the east of the entrance of the Panama Canal than from those to the west. No seasonal differences in the food were observed. The volume of material in the stomachs ranged from almost none to nearly 1.0 milliliter, with an average of a little more than 0.2 milliliter. Twenty-six bottom samples were examined; the organisms found corresponded very closely to those encountered in the stomachs of the adult fish. It is concluded that the juvenile anchovetas are chiefly or entirely filter feeders of the pelagic zone. The adults, however, are mostly iliophagous feeders, but possibly do some feeding upon plankton as well. SPANISH:Las branquispinas de las anchovetas, tanto en las juveniles como en las adultas, son largas y numerosas, can varias protuberancias finas que hacen de ellas un aparato filtrador muy eficiente. El estómago está modificado en una molleja. El intestino está sometido a un crecimiento heterónomo, llega a alcanzar unas oeho veces la longitud estandar en las adultas. Fué examinado el contenido estomacal de 39 ,muestras de peces juveniles y de 120 adultos. Las diatomeas fueron el alimento principal de todos los peces que fueron examinados cuyo tamaño varió entre los 29 y 153 milimetros. Se encontraron también en cantidades silicoflagelados, dinoflagelados, granos de polen, foraminíferos, conchas de rotiferos, crustáceos y huevos, probablemente de crustáceos. Coscinodiscus, una diatomea, fué el alimento más importante encontrado en los estómagos de los peces juveniles. No se observaron mayores diferencias en los hábitos de alimentación en los juveniles de diferentes tamaños. Aún tomando en cuenta su tamaño menor, los juveniles tenian volúmenes más pequeños de material y un número menor de organismos en sus estómagos que los adultos. Los estómagos de los peces adultos, diferentes a los de los juveniles, contenían por lo general considerables cantidades de fango. Melosira, Coscinodiscus, y Thalassionema, todas ellas diatomeas, fueron los organismos más importantes encontrados en los estómagos de los adultos. La contribuciónde Melosira fué mucho más alta en los estómagos de los peces procedentes de las áreas al este de la entrada del Canal de Panamá que la de aquellos provenientes del oeste. No se observaron diferencias estacionales en la alimentacion. El volúmen de material en los estómagos varió de casi cero a cerca de 1.0 mililitros, con un promedio de un poco mas de 0.2 mili1itros. Se examinaron 26 muestras de fonda; los organismos encontrados correspondieron muy cercanamente a los hallados en los estómagos de los peces adultos. Se ha llegado a la conclusión de que las anchovetas juveniles son principalmente ó enteramente filtradoras de alimentos de la zona pelágica. Las adultas, sin embargo, son en su mayoria iliófagas, pero posiblemente se alimentan también de plancton.
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A pictorial key to US genera of free-living marine nematodes in the order Enoplida is presented. Specific morphological and anatomical features are iUustrated to facilitate use of the key. The purpose of this work is to provide a single key to the genera of enoplid nematodes to facilitate identification of these organisms by nematologists and marine biologists working with meiofauna. (PDF file contains 32 pages.)
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The food habits of 20 species of pelagic nekton were investigated from collections made with small-mesh purse seines from 1979-84 off Washington and Oregon. Four species (spiny dogfish, Squalus acanthias; soupfin shark, Galeorhinus zyopterus; blue shark, Prionace glauca; and cutthroat trout, Salmo clarki) were mainly piscivorous. Six species (coho salmon, Oncorhynchus kisutch; chinook salmon, O. tshawytscha; black rockfish, Sebastes melanops; yellowtail rockfish, S. f1avidus; sablefish, Anoplopoma fimbria; and jack mackerel, Trachurus symmetricus) consumed both nektonic and planktonic organisms. The remaining species (market squid, Loligo opalescens; American shad, Alosa sapidissima; Pacific herring, Clupea harengus pallasi; northern anchovy, Engraulis mordax; pink salmon, O. gorbuscha; surf smelt, Hypomesus pretiosus; Pacific hake, Merluccius productus; Pacific saury, Cololabis saira; Pacific mackerel, Scomber japonicus; and medusafish, Icichthys lockingtom) were primarily planktonic feeders. There were substantial interannual, seasonal, and geographic variations in the diets of several species due primarily to changes in prey availability. Juvenile salmonids were not commonly consumed by this assemblage of fishes (PDF file contains 36 pages.)
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This bibliography contains 73 annotated references from publications and reports concerning hypoxia, .,; 2.0 ppm dissolved oxygen concentration, in the Gulf of Mexico. Instances of hypoxia from similar habitats and the effects of low oxygen levels on marine or estuarine organisms are also included. (PDF file contains 15 pages.)
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A concept for joint research on aquaculture in the Baltic Sea area is presented. It consists of three major parts, the promotion of an aquaculture-based-fisheries, the development of low-output land-based aquaculture systems, and the search for sustainably produced substances from aquatic organisms to be used for different processes. They include substitutes for feeding stuffs or products of importance for medical, biotechnological and industrial applications.