31 resultados para human population
em Aquatic Commons
Resumo:
Key Messages [pdf, 2.5 Mb] Climate Information Gaps Ocean Productivity Information gaps Living Marine Resources Information gaps Climate [pdf, 1.8 Mb] Productivity [pdf, 5.2 Mb] Nutrients Phytoplankton Zooplankton Living Resources [pdf, 10 Mb] Subarctic coastal systems Central oceanic gyres Temperate coastal and oceanic systems Marine mammals The Human Population [pdf, 5 Mb] Contaminants and Habitat Modifications Aquaculture Knowledge Gaps Glossary Ocean and Climate Changes [pdf, 4.1Mb] Highlights Introduction Atmospheric Indices Change in 1998/99 Comparison of Atmospheric Indices Authorship Yellow Sea / East China Sea [pdf, 2.3 Mb] Highlights Background Status and Trends Hydrography Chemistry Plankton Benthos Fish and invertebrates Marine birds and mammals Issues Critical factors causing change Authorship Japan/East Sea [pdf, 3.3 Mb] Highlights Background Status and Trends Hydrography Chemistry Plankton Fish and Invertebrates Marine Birds and Mammals Critical factors causing change Issues Authorship Okhotsk Sea [pdf, 1.7 Mb] Background Status and Trends Climate Hydrography Chemistry Plankton Fish and Invertebrates Marine Birds and Mammals Issues Critical factors causing change Authorship Oyashio / Kuroshio [pdf, 4.5 Mb] Highlights Background Status and Trends Hydrography Plankton Fish and Invertebrates Marine Birds and Mammals Issues Authorship Western Subarctic Gyre [pdf, 4.5 Mb] Highlights Background Status and Trends Hydrography Chemistry Plankton Fish and Invertebrates Marine Birds and Mammals Issues Authorship Bering Sea [pdf, 2.2 Mb] Highlights Background Status and Trends Hydrography Chemistry Plankton Fish and Invertebrates Marine Birds and Mammals Critical Factors Causing Change Issues Authorship Gulf of Alaska [pdf, 2.6 Mb] Highlights Background Status and trends Hydrography Chemistry Plankton Fish and Invertebrates Marine birds and mammals Critical factors causing change Issues Authorship California Current [pdf, 2.7 Mb] Highlights Background Status and Trends Hydrography Chemistry Plankton Fish and Invertebrates Marine Birds and Mammals Critical Factors Causing Change Issues Authorship Gulf of California [pdf, 1.7 Mb] Highlights Background Status and Trends Hydrography Chemistry Plankton Fisheries Marine Birds and Mammals Critical Factors Causing Change Issues Authorship Transition Zone [pdf, 2.5 Mb] Background Status and Trends Hydrography Chemistry Plankton Fish and Invertebrates Marine Birds and Mammals Issues Authorship Tuna [pdf, 1.5 Mb] Highlights Background Pacific bluefin tuna Albacore tuna Status and trends Ecosystem model and climate forcing Authorship Pacific halibut [pdf, 1.1 Mb] Background The Fishery Climate Influences Authorship Pacific salmon [Updated, pdf, 0.4 Mb] Background Status and Trends Washington, Oregon, and California British Columbia Southeast Alaska Central Alaska Western Alaska Russia Japan Authorship References [pdf, 0.5 Mb]
Resumo:
Analyses of blood and liver samples from live captured sea otters and liver samples from beachcast sea otter carcasses off the remote Washington coast indicate relatively low exposure to contaminants, but suggest that even at the low levels measured, exposure may be indicated by biomarker response. Evidence of pathogen exposure is noteworthy - infectious disease presents a potential risk to Washington sea otters, particularly due to their small population size and limited distribution. During 2001 and 2002, 32 sea otters were captured, of which 28 were implanted with transmitters to track their movements and liver and blood samples were collected to evaluate contaminant and pathogen exposure. In addition, liver samples from fifteen beachcast animals that washed ashore between 1991 and 2002 were analyzed to provide historical information and a basis of reference for values obtained from live otters. The results indicate low levels of metals, butyltins, and organochlorine compounds in the blood samples, with many of the organochlorines not detected except polychlorinated biphenyls (PCBs), and a few aromatic hydrocarbons detected in the liver of the live captured animals. Aliphatic hydrocarbons were measurable in the liver from the live captured animals; however, some of these are likely from biogenic sources. A significant reduction of vitamin A storage in the liver was observed in relation to PCB, dibutyltin and octacosane concentration. A significant and strong positive correlation in vitamin A storage in the liver was observed for cadmium and several of the aliphatic hydrocarbons. Peripheral blood mononuclear cell (PBMC) cytochrome P450 induction was elevated in two of 16 animals and may be potentially related to aliphatic and aromatic hydrocarbon exposure. Mean concentration of total butyltin in the liver of the Washington beach-cast otters was more than 15 times lower than the mean concentration reported by Kannan et al. (1998) for Southern sea otters in California. Organochlorine compounds were evident in the liver of beach-cast animals, despite the lack of large human population centers and development along the Washington coast. Concentrations of PCBs and chlordanes (e.g., transchlordane, cis-chlordane, trans-nonachlor, cis-nonachlor and oxychlordane) in liver of Washington beach-cast sea otters were similar to those measured in Aleutian and California sea otters, excluding those from Monterey Bay, which were higher. Mean concentrations of 1,1,1,- trichloro-2,2-bis(p-chlorophyenyl)ethanes (DDTs) were lower, and mean concentrations of cyclohexanes (HCH, e.g., alpha BHC, beta BHC, delta BHC and gamma BHC) were slightly higher in Washington beach-cast otters versus those from California and the Aleutians. Epidemiologically, blood tests revealed that 80 percent of the otters tested positive for morbillivirus and 60 percent for Toxoplasma, the latter of which has been a significant cause of mortality in Southern sea otters in California. This is the first finding of positive morbillivirus titers in sea otters from the Northeast Pacific. Individual deaths may occur from these diseases, perhaps more so when animals are otherwise immuno-compromised or infected with multiple diseases, but a population-threatening die-off from these diseases singly is unlikely while population immunity remains high. The high frequency of detection of morbillivirus and Toxoplasma in the live otters corresponds well with the cause of death of stranded Washington sea otters reported herein, which has generally been attributable to infectious disease. Washington’s sea otter population continues to grow, with over 1100 animals currently inhabiting Washington waters; however, the rate of growth has slowed over recent years. The population has a limited distribution and has not yet reached its carrying capacity and as such, is still considered at high risk to catastrophic events. (PDF contains 189 pages)
Resumo:
Although maritime regions support a large portion of the world’s human population, their value as habitat for other species is overlooked. Urban structures that are built in the marine environment are not designed or managed for the habitat they provide, and are built without considering the communities of marine organisms that could colonize them (Clynick et al., 2008). However, the urban waterfront may be capable of supporting a significant proportion of regional aquatic biodiversity (Duffy-Anderson et al., 2003). While urban shorelines will never return to their original condition, some scientists think that the habitat quality of urban waterfronts could be significantly improved through further research and some design modifications, and that many opportunities exist to make these modifications (Russel et al., 1983, Goff, 2008). Habitat enhancing marine structures (or HEMS) are a potentially promising approach to address the impact of cities on marine organisms including habitat fragmentation and degradation. HEMS are a type of habitat improvement project that are ecologically engineered to improve the habitat quality of urban marine structures such as bulkheads and docks for marine organisms. More specifically, HEMS attempt to improve or enhance the physical habitat that organisms depend on for survival in the inter- and sub-tidal waterfronts of densely populated areas. HEMS projects are targeted at areas where human-made structures cannot be significantly altered or removed. While these techniques can be used in suburban or rural areas restoration or removal is preferred in these settings, and HEMS are resorted to only if removal of the human-made structure is not an option. Recent research supports the use of HEMS projects. Researchers have examined the communities found on urban structures including docks, bulkheads, and breakwaters. Complete community shifts have been observed where the natural shoreline was sandy, silty, or muddy. There is also evidence of declines in community composition, ecosystem functioning, and increases in non-native species abundances in assemblages on urban marine structures. Researchers have identified two key differences between these substrates including the slope (seawalls are vertical; rocky shores contain multiple slopes) and microhabitat availability (seawalls have very little; rocky shores contain many different types). In response, researchers have suggested designing and building seawalls with gentler slopes or a combination of horizontal and vertical surfaces. Researchers have also suggested incorporating microhabitat, including cavities designed to retain water during low tide, crevices, and other analogous features (Chapman, 2003; Moreira et al., 2006) (PDF contains 4 pages)
Resumo:
The paper assessed qualitatively the threat status of nigerian freshwater fishes that are presently being exported and those that have potential in aquarium trade using such criteria as rarity, size at maturity, mode of reproduction, human population density, habitat degradation, pollution and range of each species among others. For their conservation captive breeding of these fishes were proffered with information that can assist collectors, exporter and aquaculturists that wants to breed polypterids, Butterfly fish, Knife fish, Elephantfish, Pollymyrus isidori, Arnordichthys spilopterus, Nannaethiops unitaeniatus, Killifishes, Polycentropsis abbreviatta, Cichlids, Ctenpomas, Mastacembelids and Tetraodon lineatus
Resumo:
The study assessed qualitatively the threat status of all nigerian freshwater fishes using such criteria as rarity, size at maturity, mode of reproduction, human population density, habitat degradation, pollution and range of each species among others. The biology of 48% (129n) of nigerian freshwater species is not well known. Of the 266 known freshwater fishes, 47 species represented 17% are critically endangered, 15 (5%) are endangered , 8(3%), are vulnerable while 23(8%) are near threatened. The paper suggests increased basic knowledge of threatened species and conservation policy along three lines public awareness, legislation and creation of national parks, aquaria and reserves as measures needed to ensure the conservation of the fishes
Resumo:
The development of bay wide estimates of recreational harvest has been identified as a high priority by the Chesapeake Bay Scientific Advisory Committee (CBSAC) and by the Chesapeake Bay Program as reflected in the Chesapeake Bay Blue Crab Fishery Management Plan (Chesapeake Bay Program 1996). In addition, the BiState Blue Crab Commission (BBCAC), formed in 1996 by mandate from the legislatures of Maryland and Virginia to advise on crab management, has also recognized the importance of estimating the levels and trends in catches in the recreational fishery. Recently, the BBCAC has adopted limit and target biological reference points. These analyses have been predicated on assumptions regarding the relative magnitude of the recreational and commercial catch. The reference points depend on determination of the total number of crabs removed from the population. In essence, the number removed by the various fishery sectors, represents a minimum estimate of the population size. If a major fishery sector is not represented, the total population will be accordingly underestimated. If the relative contribution of the unrepresented sector is constant over time and harvests the same components of the population as the other sectors, it may be argued that the population estimate derived from the other sectors is biased but still adequately represents trends in population size over time. If either of the two constraints mentioned above is not met, the validity of relative trends over time is suspect. With the recent increases in the human population in the Chesapeake Bay watershed, there is reason to be concerned that the recreational catch may not have been a constant proportion of the total harvest over time. It is important to assess the catch characteristics and the magnitude of the recreational fishery to evaluate this potential bias. (PDF contains 70 pages)
Resumo:
The potential importance of marine produetion as a protein ressource for a growing human population can hardly be overestimated. Climatic changes in the marine environment may affect marine production in a significant way. Increasing levels of UV-B may decrease primary production and thus diminish the food base for harvestable marine ressources. Direct effects on early stages of fishes may occur. Temperature changes can lead to additional mortality in the early phase of life histories of fishes. In spite of the potentially negative scenario, actual effects of global change on the ressources have not been detected so far. The marine organisms dispose of a significant level of pre-adaptation to changes of environmental factors both on a seasonal and an interannual scale. Effects on marine life may therefore be less dramatic than those on terrestrial systems, which are more directly linked with the exponentially growing human population.
Resumo:
The total coliforms, fecal coliforms and fecal streptococci were counted over 1 year at 33 stations in the Ebrié Lagoon near Abidjan (Ivory Coast). Most of the waters show high numbers of bacteria, (D category of the American standards). For the sea-beaches, high numbers of fecal germs are found where the human population is abundant.
Resumo:
Lake Victoria, in East Africa, has suffered from introductions and invasions of non-native species such as Lates niloticus, various tilapiine species, and Eichornia crassipes since the 1950s. These have had a devastating effect on the natural biological communities. This paper reviews the effects of the introductions on ecology, environment, fisheries and the local human population.
Resumo:
Fishing is widely recognized to have profound effects on estuarine and marine ecosystems (Hammer and Jansson, 1993; Dayton et al., 1995). Intense commercial and recreational harvest of valuable species can result in population collapses of target and nontarget species (Botsford et al., 1997; Pauly et al., 1998; Collie et al. 2000; Jackson et al., 2001). Fishing gear, such as trawls and dredges, that are dragged over the seafloor inflict damage to the benthic habitat (Dayton et al., 1995; Engel and Kvitek, 1995; Jennings and Kaiser, 1998; Watling and Norse, 1998). As the growing human population, over-capitalization, and increasing government subsidies of fishing place increasing pressures on marine resources (Myers, 1997), a clear understanding of the mechanisms by which fishing affects coastal systems is required to craft sustainable fisheries management.
Resumo:
The bay scallop, Argopecten irradians, supported a small commercial fishery in Florida from the late 1920’s through the 1940’s; peak landings were in 1946 (214,366 lbs of meats), but it currently supports one of the most popular and family-oriented fisheries along the west coast of Florida. The primary habitat of the short-lived (18 months) bay scallop is seagrass beds. Peak spawning occurs in the fall. Human population growth and coastal development that caused habitat changes and reduced water quality probably are the main causes of a large decline in the scallop’s abundance. Bay scallop restoration efforts in bays where they have become scarce have centered on releasing pediveligers and juveniles into grass beds and holding scallops in cages where they would
Resumo:
Aboriginal Australians consumed oysters before settlement by Europeans as shown by the large number of kitchen middens along Australia's coast. Flat oysters, Ostrea angasi, were consumed in southeastern Australia, whereas both flat and Sydney rock oysters, Saccostrea glomerata, are found in kitchen middens in southern New South Wales (NSW), but only Sydney rock oysters are found in northern NSW and southern Queensland. Oyster fisheries began with the exploitation of dredge beds, for the use of oyster shell for lime production and oyster meat for consumption. These natural oyster beds were nealy all exhausted by the late 1800's, and they have not recovered. Oyster farming, one of the oldest aquaculture industries in Australia, began as the oyster fisheries declined in the late 1800's. Early attempts at farming flat oysters in Tasmania, Victoria, and South Australia, which started in the 1880's, were abandoned in the 1890's. However, a thriving Sydney rock oyster industry developed from primitive beginnings in NSW in the 1870's. Sydney rock oysters are farmed in NSW, southern Queensland, and at Albany, Western Australia (WA). Pacific oysters, Crassostrea gigas, are produced in Tasmania, South Australia, and Port Stephens, NSW. FLant oysters currently are farmed only in NSW, and there is also some small-scale harvesting of tropical species, the coarl rock or milky oyster, S. cucullata, and th black-lip oyster, Striostrea mytiloides, in northern Queensland. Despite intra- and interstate rivalries, oyster farmers are gradually realizing that they are all part of one industry, and this is reflected by the establishment of the national Australian Shellfish Quality Assuarance Program and the transfer of farming technology between states. Australia's oyster harvests have remained relatively stable since Sydney rock oyster production peaked in the mid 1970's at 13 million dozen. By the end of the 1990's this had stabilized at around 8 million dozen, and Pacific oyster production reached a total of 6.5 million dozen from Tasmania, South Australia, and Port Stephens, a total of 14.5 million dozen oysters for the whole country. This small increase in production during a time of substantial human population growth shows a smaller per capita consumption and a declining use of oysters as a "side-dish."
Resumo:
Raritan Bay is the body of water bounded by New York and New Jersey and lying immediately south of New York City (Fig. 1). It has close proximity to the most concentrated urban and industrial area in the United States. Its history has been one of extensive multiple use by the surrounding human population. Dating from the precolonial and colonial periods, people have employed many types of gear to catch and gather its once abundant fishes and shellfishes. Its beaches were once popular for sun bathing and swimming, but after the 1940's they were essentially abandoned because the water became too polluted. Another large use has been for pleasure boating and the transit and dockage of merchant, passenger, and military vessels. Channels and basins were dug in the bay, bulkheads and jetties were constructed along its shores, and it was a donor source of sand and gravel for construction projects. It has also been a receptor for large quantities of domestic and industrial wastes and, mainly for this reason, it is one ofthe most deteriorated estuaries in the United States.
Resumo:
This CD contains summary data of bottlenose dolphins stranded in South Carolina using a Geographical Information System (GIS) and contains two published manuscripts in .pdf files. The intent of this CD is to provide data on bottlenose dolphin strandings in South Carolina to marine mammal researchers and managers. This CD is an accumulation of 14 years of stranding data collected through the collaborations of the National Ocean Service, Center for Coastal Environmental Health and Biomolecular Research (CCEHBR), the South Carolina Department of Natural Resources, and numerous volunteers and veterinarians that comprised the South Carolina Marine Mammal Stranding Network. Spatial and temporal information can be visually represented on maps using GIS. For this CD, maps were created to show relationships of stranding densities with land use, human population density, human interaction with dolphins, high geographical regions of live strandings, and seasonal changes. Point maps were also created to show individual strandings within South Carolina. In summary, spatial analysis revealed higher densities of bottlenose dolphin strandings in Charleston and Beaufort Counties, which consist of urban land with agricultural input. This trend was positively correlated with higher human population levels in these coastal counties as compared with other coastal counties. However, spatial analysis revealed that certain areas within a county may have low human population levels but high stranding density, suggesting that the level of effort to respond to strandings is not necessarily positively correlated with the density of strandings in South Carolina. Temporal analysis revealed a significantly higher density of bottlenose dolphin strandings in the northern portion of the State in the fall, mostly due to an increase of neonate strandings. On a finer geographic scale, seasonal stranding densities may fluctuate depending on the region of interest. Charleston Harbor had the highest density of live bottlenose dolphin strandings compared to the rest of the State. This was due in large part to the number of live dolphin entanglements in the crab pot fishery, the largest source of fishery-related mortality for bottlenose dolphins in South Carolina (Burdett and McFee 2004). Spatial density calculations also revealed that Charleston and Beaufort accounted for the majority of dolphins that were involved with human activities. 1
Resumo:
There is a pressing need to integrate biophysical and human dimensions science to better inform holistic ecosystem management supporting the transition from single species or single-sector management to multi-sector ecosystem-based management. Ecosystem-based management should focus upon ecosystem services, since they reflect societal goals, values, desires, and benefits. The inclusion of ecosystem services into holistic management strategies improves management by better capturing the diversity of positive and negative human-natural interactions and making explicit the benefits to society. To facilitate this inclusion, we propose a conceptual model that merges the broadly applied Driver, Pressure, State, Impact, and Response (DPSIR) conceptual model with ecosystem services yielding a Driver, Pressure, State, Ecosystem service, and Response (EBM-DPSER) conceptual model. The impact module in traditional DPSIR models focuses attention upon negative anthropomorphic impacts on the ecosystem; by replacing impacts with ecosystem services the EBM-DPSER model incorporates not only negative, but also positive changes in the ecosystem. Responses occur as a result of changes in ecosystem services and include inter alia management actions directed at proactively altering human population or individual behavior and infrastructure to meet societal goals. The EBM-DPSER conceptual model was applied to the Florida Keys and Dry Tortugas marine ecosystem as a case study to illustrate how it can inform management decisions. This case study captures our system-level understanding and results in a more holistic representation of ecosystem and human society interactions, thus improving our ability to identify trade-offs. The EBM-DPSER model should be a useful operational tool for implementing EBM, in that it fully integrates our knowledge of all ecosystem components while focusing management attention upon those aspects of the ecosystem most important to human society and does so within a framework already familiar to resource managers.