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Role of network analysis in comparative ecosystem ecology of estuaries

Robert R. Christian, Daniel Baird, Joseph Luczkovich, Jeffrey C. Johnson, Ursula M. Scharler, and Robert E. Ulanowicz

in Aquatic Food Webs: An ecosystem approach

Estuaries are excellent ecosystems for testing the veracity of the inferences of ecological network analysis for three reasons. First, more network analyses have been conducted on estuaries than any ... More

Estuaries are excellent ecosystems for testing the veracity of the inferences of ecological network analysis for three reasons. First, more network analyses have been conducted on estuaries than any other kind of ecosystem. Second, estuarine environments are often stressed by natural and anthropogenic forcings. These conditions allow hypotheses of response to stress to be formulated and tested. Finally, sampling of estuaries has often been extensive, such that reasonable food webs can be constructed under different conditions of stress. This chapter reviews studies that incorporate these three elements, and assesses how efficacious analysis output variables are at describing the effects of stress. Output variables index a range of trophic dynamic properties from populations to entire food webs. The assessment is structured in the context of this range.Less

COASTS

Ernest H. Williams

in The Nature Handbook: A Guide to Observing the Great Outdoors

The habitats of coastal margins include marshes, estuaries, mud flats, sand dunes, rocky shores, and coastal forests, all of which are influenced by salt spray and the rising and falling of tidal ... More

The habitats of coastal margins include marshes, estuaries, mud flats, sand dunes, rocky shores, and coastal forests, all of which are influenced by salt spray and the rising and falling of tidal waters. The intertidal gradient from high and dry to continuously submerged strongly affects plants and animals because the physical conditions for life change so dramatically over such a short distance. A number of observations described in this chapter reflect the differences across the intertidal zone.Less

Estuarine respiration: an overview of benthic, pelagic, and whole system respiration

Charles S. Hopkinson and Erik M. Smith

in Respiration in Aquatic Ecosystems

This chapter reviews the rates of benthic, pelagic, and whole system respiration in estuaries. Estuaries are defined as semi-enclosed coastal bodies of water with some degree of mixing between fresh ... More

This chapter reviews the rates of benthic, pelagic, and whole system respiration in estuaries. Estuaries are defined as semi-enclosed coastal bodies of water with some degree of mixing between fresh and salt water. Rates of respiration in these locations are high, reflecting high rates of organic loading from both autochthonous and allochthonous sources. Areal rates of pelagic respiration (58-114 mmol C/m2-d) are 2-4 times higher than benthic respiration rates (34 mmol C/m2-d), consistent with estimates that only about 24% of total organic inputs to estuaries are respired by the benthos. Estimates of whole system respiration derived from open-water techniques (294 mmol C/m2-d) are substantially higher than those obtained by summing component rates (92-148 mmol C/m2-d), this is most likely due to the different spatial scales sampled by the two different approaches.Less

The Main Results of the Excavations at Olbia in the Past Three Decades

S. D. KRYZHITSKIY

in Classical Olbia and the Scythian World: From the Sixth Century BC to the Second Century AD

In the 1790s, the location of Olbia was established, and since 1901 systematic excavations have been made by three successive generations of scholars. The first of these scholars was Pharmakovskiy ... More

In the 1790s, the location of Olbia was established, and since 1901 systematic excavations have been made by three successive generations of scholars. The first of these scholars was Pharmakovskiy and his school in 1901–1926. The second scholars to make excavations in Olbia were under the leadership of Slavin, Levi and Karasev. The third generation who took over the excavations from 1972 was headed by Kryzhitskiy from 1972–1995 and Krapivina from 1995. This chapter focuses on the contributions made by the third generation of scholars that made excavations in the Olbia region. The excavations made in this period were governed by three aims: the study of the historico-archaelogical stratigraphy and topography of cultural levels in the various parts of the city including the underwater area beneath the Bug estuary; an emphasis on the least-studied phases of the city's existence, particularly the cultural levels of the archaic period and the early centuries AD; and the rescue and conservation of the coastal portion of the city. The excavations generated important results such as the discovery of the temenos wall, altars, the temple of Apollo Ietros, Hellenistic period citadels and dwellings, and defensive walls belonging to the fifth century. In addition to these excavations and discoveries, the teams headed by Kryzhitskiy and Krapivina made extensive studies on the lower Bug estuary and Olbia's chora.Less

Of a shipwreck on the island of Cáliz, which the indians call parataure, which is in the mouth of the Huyapari River; and of the sufferings of some Spaniards of the army of Governor Hierónimo Dortal.

Gonzalo Fernández de Oviedo

in Misfortunes and Shipwrecks in the Seas of the Indies, Islands, and Mainland of the Ocean Sea (1513–1548): Book Fifty of the 'General and Natural History of the Indies'

This chapter describes the shipwreck and very perilous journey that happened to the people of Governor Hierónimo Dortal. While he was going to the banks of the great and famous Huyapari River, ... More

This chapter describes the shipwreck and very perilous journey that happened to the people of Governor Hierónimo Dortal. While he was going to the banks of the great and famous Huyapari River, Governor Dortal sent some people and ships under Captain Alonso de Herrera to settle at a town called Aruacay. However, there they found the town abandoned, and the captain and the Spaniards crossed to the other bank of the same river to a town called Capao. From there they sent the governor some gold and Indians and great news of the riches said to be had in Meta, urging him to hurry to join with them so they could go forward with the enterprise. It took them twenty days to sail a good 250 leagues to the mouth of the estuary.Less

Life in estuaries

Donald S. McLusky and Michael Elliott

in The Estuarine Ecosystem: Ecology, Threats and Management

This chapter considers the general features that are common to plants and animals in estuaries. All the plants and animals in estuaries originate from either the sea or from freshwaters. They either ... More

This chapter considers the general features that are common to plants and animals in estuaries. All the plants and animals in estuaries originate from either the sea or from freshwaters. They either enter estuaries as part of a movement or migration during their own lifetimes, or else their ancestors entered estuaries and successive generations have become settled within estuaries, so that it is now the only habitat for some species. The species living in estuaries fall into several categories: Oligohaline organisms, True estuarine organisms, euryhaline marine organisms, stenohaline marine organisms, and Migrants. Many studies of the distribution and abundance of animals and plants in estuaries have shown that the number of species within estuaries is less than the number of species within either the sea or fresh waters. In the major groups of species living within estuaries, a clear generalized pattern of declining diversity can be seen as one enters the estuary from either end.Less

The management of estuaries

Donald S. McLusky and Michael Elliott

in The Estuarine Ecosystem: Ecology, Threats and Management

The main objective of estuarine management is to devise a framework within which man may coexist with nature. This chapter divides estuarine management into three broad areas: policies and ... More

The main objective of estuarine management is to devise a framework within which man may coexist with nature. This chapter divides estuarine management into three broad areas: policies and philosophies, planning and designations, and practice. Policy reflects the underlying approaches and frameworks in the way we manage estuaries, which is related to the political and administrative framework. Planning is used for the process of resource allocation, be it by ecological or economic yardsticks. Practice covers the means by which we can derive and implement decisions. All of these aspects are interrelated and each follows from each other.Less

The Essential Harbor

John Waldman

in Heartbeats in the Muck: The History, Sea Life, and Environment of New York Harbor, Revised Edition

New York Harbor is a sprawling network of tidal bays, inlets, channels, and creeks set within both the broader Hudson Estuary and the urban matrix of New York City. Its geography is recent in ... More

New York Harbor is a sprawling network of tidal bays, inlets, channels, and creeks set within both the broader Hudson Estuary and the urban matrix of New York City. Its geography is recent in geological time—the product of glaciers that receded only fifteen thousand years ago. Many natural habitats may be found in the Harbor, from freshwater and brackish wetlands, to boulder and bedrock shores, to sand beaches. Its annual temperature range is extreme, resulting in a dynamic biota that changes seasonally.Less

Why Should We Care About Rivers?

Ellen E. Wohl

in Disconnected Rivers: Linking Rivers to Landscapes

This chapter focuses on the importance of rivers, and explains why humans should care about them. Rivers provide water to drink, water that helps crops to grow, and the water that fuels or cools ... More

This chapter focuses on the importance of rivers, and explains why humans should care about them. Rivers provide water to drink, water that helps crops to grow, and the water that fuels or cools industries. Water is a universal solvent and is used at some stage in the manufacture of every product that people consume. Rivers transport wastes, and to some extent transform them. If not for this self-purifying function of rivers, many estuaries and deltas would be even more polluted. Rivers transport goods, generate power, and sustain recreation. The chapter emphasizes that the society which does not protect its rivers destroys its own lifelines. It also reveals that despite the history of public awareness of environmental issues in America, many people remain unaware of how substantially human activities have altered rivers across the nation.Less

Where the Dry Forest Feeds the Sea: The Gulf of Nicoya Estuary

José A. Vargas and Alfonso Mata

in Biodiversity Conservation in Costa Rica: Learning the Lessons in a Seasonal Dry Forest

This chapter focuses on the Gulf of Nicoya estuary located in the northwestern part of the Pacific coast of Costa Rica. It discusses the main physical, chemical, and biological features of the ... More

This chapter focuses on the Gulf of Nicoya estuary located in the northwestern part of the Pacific coast of Costa Rica. It discusses the main physical, chemical, and biological features of the estuary. It also discusses some control initiatives for the rational use and the protection of resources in the Gulf of Nicoya, including the reduction of habitat destruction, and control of pollution sources, and support for environmental education and ecological research.Less

Origin and Geomorphology

Thomas S. Bianchi

in Biogeochemistry of Estuaries

Geologically speaking, estuaries are ephemeral features of the coasts. Upon formation, most begin to fill in with sediments and, in the absence of sea level changes, would have life spans of only a ... More

Geologically speaking, estuaries are ephemeral features of the coasts. Upon formation, most begin to fill in with sediments and, in the absence of sea level changes, would have life spans of only a few thousand to tens of thousands of years (Emery and Uchupi, 1972; Schubel, 1972; Schubel and Hirschberg, 1978). Estuaries have been part of the geologic record for at least the past 200 million years (My) BP (before present; Williams, 1960; Clauzon, 1973). However, modern estuaries are recent features that only formed over the past 5000 to 6000 years during the stable interglacial period of the middle to late Holocene epoch (0–10,000 y BP), which followed an extensive rise in sea level at the end of the Pleistocene epoch (1.8 My to 10,000 y BP; Nichols and Biggs, 1985). There is general agreement that four major glaciation to interglacial periods occurred during the Pleistocene. It has been suggested that sea level was reduced from a maximum of about 80 m above sea level during the Aftoninan interglacial to 100 m below sea level during the Wisconsin, some 15,000 to 18,000 y BP (figure 2.1; Fairbridge, 1961). This lowest sea level phase is referred to as low stand and is usually determined by uncovering the oldest drowned shorelines along continental margins (Davis, 1985, 1996); conversely, the highest sea level phase is referred to as high stand. It is generally accepted that low-stand depth is between 130 and 150 m below present sea level and that sea level rose at a fairly constant rate until about 6000 to 7000 y BP (Belknap and Kraft, 1977). A sea level rise of approximately 10 mm y−1 during this period resulted in many coastal plains being inundated with water and a displacement of the shoreline. The phenomenon of rising (transgression) and falling (regression) sea level over time is referred to as eustacy (Suess, 1906). When examining a simplified sea level curve, we find that the rate of change during the Holocene is fairly representative of the Gulf of Mexico and much of the U.S. Atlantic coastline (Curray, 1965). Less

Sea Level Rise and Sustainability in Chesapeake Bay Coastal Archaeology

Leslie Reeder-Myers, Torben C. Rick, and Victor D. Thompson

Leslie Reeder-Myers, John A. Turck, and Torben C. Rick (eds)

in The Archaeology of Human-Environmental Dynamics on the North American Atlantic Coast

The productive woodlands, estuaries, and coastlines of the Middle Atlantic region of North America have been home to Native Americans from the Paleoindian period to the modern day. Inhabitants of ... More

The productive woodlands, estuaries, and coastlines of the Middle Atlantic region of North America have been home to Native Americans from the Paleoindian period to the modern day. Inhabitants of this region adapted to broad environmental changes, including the emergence of Chesapeake Bay when rising seas drowned the Susquehanna River valley around 8000 years ago. Estuarine conditions expanded throughout the Holocene, alongside the establishment of a rich and diverse forest environment. Much of the evidence for human harvesting of coastal resources has likely been obscured by sea level rise and modern development, but first appears around 5000 years BP. By the Middle Woodland (2500 to 1100 BP), people were harvesting oysters, clams, fish, and other bay resources as part of a broad foraging subsistence. When Europeans arrived, at least some of the people living around Chesapeake Bay were practicing agriculture while also harvesting oysters and other resources. Oyster harvesting was remarkably consistent and sustainable through time, with minimal impact on oyster populations or other environmental conditions. This long history of sustainable fishing practices in the face of persistent sea level rise and climate change suggests that reduced harvest pressure may be a key component to restoring modern Chesapeake ecosystems.Less

Habitat, Water Quality, and Conservation Biology

Bruce S. Miller and Arthur W. Kendall

in Early Life History of Marine Fishes

This chapter begins by discussing the variety of habitats that are occupied by fish eggs and larvae; these habitats include the open ocean, coastal ocean, and estuaries. Also, the chapter discusses ... More

This chapter begins by discussing the variety of habitats that are occupied by fish eggs and larvae; these habitats include the open ocean, coastal ocean, and estuaries. Also, the chapter discusses the stage-specificity of the area of occurrence of each stage (adults, eggs, larvae, juveniles) in the life history of fishes, pointing out the differences of demersal, pelagic, neustonic (associated with the very surface of the water), anadromous (fish that migrate from the ocean to fresh water to spawn), catadromus (fish that migrate from fresh water to the ocean to spawn), and estuarine or coastal fishes. The effect of human activity and pollution on water quality and fish habitats is discussed as well. This chapter also discusses conservation biology, marine protected areas, and fisheries management.Less

The Physical Development of the Tay Estuary in the Twentieth Century and its Impact

Rob Duck

in Jute No More: Transforming Dundee

Dundee has a truly dramatic location on the north bank of Tay Estuary, which has for many years been widely regarded as the cleanest major estuary in Europe. This chapter discusses developments in ... More

Dundee has a truly dramatic location on the north bank of Tay Estuary, which has for many years been widely regarded as the cleanest major estuary in Europe. This chapter discusses developments in the twentieth century that helped reshape the Tay Estuary, modify its form and its flow dynamics, and impact upon its natural capacity to accommodate the tidal influx of water. The largest and most influential coastal protection scheme in the Tay was a 3-kilometre-long rock armour revetment built by the Ministry of Defence in 1992–3. to protect the east-facing side of the promontory of Buddon Ness. This massive, visually intrusive structure has served to protect the promontory from wave attack but in so doing has cut off what is a natural source of beach sand for the Tay.Less

Native American Use of Seals, Sea Lions, and Sea Otters in Estuaries of Northern Oregon and Southern Washington

Madonna L. Moss and Robert J. Losev

in Human Impacts on Seals, Sea Lions, and Sea Otters: Integrating Archaeology and Ecology in the Northeast Pacific

Over the last twenty-five years, archaeologists have compiled a substantial zooarchaeological record of pinnipeds on the Washington, Oregon, and California coasts. Archaeological studies have also ... More

Over the last twenty-five years, archaeologists have compiled a substantial zooarchaeological record of pinnipeds on the Washington, Oregon, and California coasts. Archaeological studies have also shown that patterns of pinniped species abundance and distribution in the late twentieth century do not necessarily reflect conditions in the ancient past, while recent biological studies demonstrate range expansion of some species subsequent to the Marine Mammal Protection Act of 1972. Archaeologists disagree over what the zooarchaeological record reveals about Native American hunting during pre-contact times. Did pinnipeds regularly use mainland breeding areas prior to human use? Did Native Americans club pinnipeds on their terrestrial breeding areas or use watercraft and specialized technologies to hunt at sea? Did Native American hunting cause changes in pinniped or sea otter behavior and migration patterns? This chapter explores Native American use of seals, sea lions, and sea otters in the estuaries of northern Oregon and southern Washington.Less

Adapting to Change in Australian Estuaries: Oysters in the Techno-Fix Cycles of Colonial Capitalism

Jodi Frawley

in Environments of Empire: Networks and Agents of Ecological Change

In the 1880s, Eastern Australian estuaries supported thriving oyster industries. They supplied lime for building early in Australia’s development, but as cities and towns grew, it was the briny salty ... More

In the 1880s, Eastern Australian estuaries supported thriving oyster industries. They supplied lime for building early in Australia’s development, but as cities and towns grew, it was the briny salty taste for this delicacy that saw the growth of the sector. When the oyster beds at the east coast of Australia became depleted, fishermen looked to New Zealand, where the same Oyster species grew, to supply cultivation stock for the Australian market. It was presumed that transfers would have the same impact as those already being moved within the Australian ecological networks. That is: it would present no problem at all. What was overlooked in this intercolonial exchange was the presence of the mudworm in the New Zealand estuaries. Mudworm co-habitats with oysters without killing them, but impedes the healthy development of the oysters making them inedible. This chapter places the mudworm at the center of a new narrative in the ecological networks of oysters. Rather than articulating the mudworm as a damaging invasive species, it argues that the mudworm was an agent of change that caused the fishermen to adjust their methods of oyster cultivation.Less