Estuarine Ecology (eBook)

Byron C. Crump, Kenneth H. Dunton, Jeremy M. Testa (Herausgeber)

eBook Download: EPUB

2022 | 3. Auflage
480 Seiten
Wiley (Verlag)
978-1-119-53456-3 (ISBN)

Infos

Estuarine Ecology

A detailed and accessible exploration of the fundamentals and the latest advances in estuarine ecology

In the newly revised third edition of Estuarine Ecology, a team of distinguished ecologists presents the current knowledge in estuarine ecology with particular emphasis on recent trends and advances. The book is accessible to undergraduate students while also providing a welcome summary of up-to-date content for a more advanced readership.

This latest edition is optimized for classroom use, with a more intuitive mode of presentation that takes into account feedback from the previous edition's readers. Review questions and exercises have been added to assist in the learning and retention of complex concepts.

Estuarine Ecology remains the gold standard for the discipline by taking stock of the manifold scientific breakthroughs made in the field since the last edition was written. It also offers:

• Thorough introductions to estuarine geomorphology, circulation, and chemistry
• In-depth treatments of estuarine primary and secondary production, including coastal marshes and mangrove wetlands
• A holistic view of estuarine ecosystems, their modeling and analysis, as well as the impact of human activities and climate change
• A companion website with detailed answers to exercise questions

Perfect for students of estuarine ecology, environmental science, fisheries science, oceanography, and natural resource management, Estuarine Ecology will also earn a place in the libraries of professionals, government employees, and consultants working on estuary and wetlands management and conservation.

Byron C. Crump, PhD, Oregon State University, USA

Jeremy M. Testa, PhD, University of Maryland Center for Environmental Science, USA

Kenneth H. Dunton, PhD, University of Texas at Austin, USA

Inhalt

1. Introduction to Estuarine Ecology

2.Estuarine Geomorphology, Circulation, and Mixing

3. Estuarine Chemistry

4. Estuarine Phytoplankton

5. Estuarine Seagrasses

6. Coastal Marshes

7. Mangrove Wetlands

8. Estuarine Benthic Algae

9. Estuarine Microbial Ecology

10. Estuarine Zooplankton

11. Estuarine Benthos

12. Estuarine Nekton

13. Estuarine Wildlife

14. Estuarine Ecosystem Metabolism

15. Estuarine Food Webs

16. Estuarine Ecological Modeling

17. Estuarine Fisheries and Aquaculture

18. Global Climate Change and Estuarine Systems

Textauszug

CHAPTER 1
Introduction to Estuarine Ecology

Kenneth H. Dunton1, Byron C. Crump2, Jeremy M. Testa3, and John W. Day4

1 University of Texas at Austin, Marine Science Institute, Port Aransas, TX, USA

2 College of Earth, Ocean, and Atmospheric Sciences, Oregon State University, Corvallis, OR, USA

3 Chesapeake Biological Laboratory, University of Maryland Center for Environmental Science, Solomons, MD, USA

4 Department of Oceanography and Coastal Sciences, Louisiana State University, Baton Rouge, LA, USA

Whooping Cranes (Grus americana) along the marsh edge within the Aransas National Wildlife Refuge on the coast of Texas, USA. These endangered native North American birds over‐winter in South Texas and migrate annually to their summer breeding and nesting grounds at Wood Buffalo National Park in northern Canada.

Photo credit: K.H. Dunton.

1.1 Background, Theory, and Issues

We begin this description of estuaries and their functions by defining estuaries very broadly as that portion of the earth’s coastal zone where there is interaction of ocean water, fresh water, land, and atmosphere. Large estuarine zones are most common in low‐relief coastal regions such as the expansive coastal plains of Europe and the east coast of North America. On glaciated coastlines at higher latitudes and on uplifted coastlines such as the Pacific coasts of Asia and the Americas, we refer to these estuarine systems as fjords. We begin our assessment as widely as possible to include all portions of the earth that interact at the edge of the sea and have produced a wide diversity of estuarine types, from coastal plain salt marshes to fjords (Figure 1.1).

From the vantage point of an orbiting satellite, several of the most basic attributes of estuaries are observable. Plumes of sediment‐laden water float seaward on the ocean surface from the largest rivers, such as the Amazon, the Ganges, and the Mississippi. Color differences among various water masses, representing waters of different histories and different biotic richness, are often apparent. Coastal waters in areas with significant riverine input and broad shelf areas generally appear more greenish‐brown than the deep blue waters adjacent to many other coastlines (Figure 1.1a). There are also atmospheric features of importance to estuaries obvious from space. Clouds commonly form directly over the edges of continents as one manifestation of the atmospheric “thermal engine” that maintains the freshwater cycle on which estuaries depend (Figure 1.1d). At the altitude of a satellite, the dense human populations that proliferate in coastal zones are outlined at night by their lights.

The most recent geological epoch, the Holocene, which started approximately 11,650 years before present, could be called the age of the estuary, for estuaries are abundant today even though they may be ephemeral on geologic timescales. It is interesting to note that all of the estuaries discussed in this book did not exist 10,000–15,000 years ago and that they will cease to exist in the near geological future. Many present‐day estuaries are less than about 5000 years old, representing the time since sea level reached near its present level following the last ice age. Since that time, they have progressively filled with sediments and that process will continue. Consequently, our present‐day estuaries will either fill with sediment or will change dramatically as sea level continues to rise.

FIGURE 1.1 Examples of common estuary types across the globe: (a) the Mission‐Aransas coastal plain salt marsh estuary includes seagrass, marsh and mangrove wetlands behind San Jose Island, a barrier island in the Gulf of Mexico, (b) the classic bar‐built estuary of Cedar Bayou (Texas coast) connects Matagorda Bay with Gulf of Mexico waters, (c) the Geiranger Fjord in western Norway, (d) an astronaut view of drowned river valleys Delaware Bay (left) and Chesapeake Bay (center), as well as coastal lagoon Pamlico Sound (top right).

Source: Earth Science and Remote Sensing Unit, NASA Johnson Space Center

(e) barrier island lagoons along the eastern Alaskan Beaufort Sea coast at breakup in June, (f) a deltaic estuary as exemplified by the vast expanses of wetlands of the Mississippi River Delta.

Source: All photos except (d) by K.H. Dunton.

Many estuaries are drowned river valleys (Figure 1.1d). Their formation began as rivers carved their way to the ocean when sea levels were considerably lower. As sea levels rose, the valleys flooded. At high latitudes, river valleys were further eroded by glaciers, resulting in profoundly deep fjords (Figure 1.1c) that became linked to the ocean through glacial melt, and the formation of a shallow entrance sill.

Human populations flourished during this same time period, in no small measure owing to exploitation of the rich estuarine resources of the coastal margin. Most “cradles of civilization” arose in deltaic and lower floodplain areas where natural biota was abundant and where flooding cycles produced the rich bottomland soils and readily available fresh water supplies on which agriculture flourished (Kennett and Kennett 2006; Day et al. 2007). Early centers of civilization that developed in estuarine or deltaic environments include the Tabascan lowlands of Mexico; the valley of the Nile, the Tigris‐Euphrates, Huang He (Yellow), and Indus River deltas, and along the Andean coast of western South America where upwelling systems bordered estuarine systems.

As human populations expanded, so did human pressure on natural environments. Today, we have entered the Anthropocene, a new epoch, defined as the period in which humans have significantly altered Earth’s environments and climate (Syvitski et al. 2020). These changes include excessive nutrient loading of our oceans (eutrophication), global climate change, rapid sea level rise, habitat loss, animal extinctions, and changes in the chemical composition of atmosphere, oceans, and soil.

Let us now continue our aerial survey of estuaries, but this time at a much lower altitude, about 1000 m, in a light airplane following the course of a coastal plain river in the temperate zone from its headwaters to the ocean. The headwater river is narrow with rapids and falls, but changes near the coast to a larger meandering form with broad marshy areas where the actual edge of the river is not always clearly evident. The color of the water changes from clear blue to yellowish‐brown as the river picks up silt. As the river water nears the coast, tidal currents become apparent and, moving seaward, the influence of tidal currents becomes greater and greater.

Along the banks of the estuary, fresh and brackish water marsh plants grow at the edges of embayments. These marshes are often flanked by rows of houses with backyards that border the bank of the estuary, often with narrow piers that extend from the bank to provide access to deeper water. Among these marshes, a variety of wading birds may be observed stalking their prey at the water’s edge. Where the water is shallow and relatively clear, dark‐colored patches indicate the presence of submersed seagrasses.

As we travel seaward, tides become more important, and the intertidal zone becomes more extensive. Larger piers and bulkheads interrupt the banks of the estuary, and brown mud flats come into view, as well as greenish‐gray oyster reefs fringing the banks or dotting the mud flats. Various birds such as oystercatchers feed on the reefs, along with an occasional raccoon. The mud flats are peppered with mud snails, and just beneath the surface are teeming communities of small worms and crustaceans. Common shore birds, such as oystercatchers and skimmers, are feeding at the water’s edge. Skimmers fly along in quiet areas, each plowing a furrow in the water with their lower bill as they fish for silversides and other small fish. The darker colored path of a deep shipping channel maintained by dredging is evident toward the middle of the estuary and contrasts with the lighter colored shallows.

The mouth of the estuary takes the form of a broad sound that opens up behind a barrier island (Figure 1.1b). The sound is shallow, and we can see porpoises herding schools of juvenile menhaden, followed by gulls trying to get in on the action. Crab pot buoys and fishing boats are much in evidence. On either side of the barrier island are narrow passes with visible eddies and strange wave patterns, indicating rapid and complex currents. In high‐latitude estuaries, river flow begins with an enormous flush at ice‐breakup, dispersing ice that formed over the previous 9 months in the estuarine lagoons protected by barrier islands (Figure 1.1e)

Along the ocean beach, several shrimp boats raise long spiraling muddy plumes of sediment as they drag their trawls along the bottom. A kilometer or so offshore of the tidal passes the water changes color from dark brownish green to a lighter, less turbid green. Further offshore it is a darker and bluer color.

On the landward side of most such barrier islands, there are flat intertidal and shallow subtidal areas colonized by salt marsh plants that are bisected with meandering tidal creeks that have developed over centuries (Figure 1.1a). In low‐latitude estuaries, these same areas are colonized with mangrove trees. Moving inland from the marsh, the highest part of the island includes larger trees. The...

Produkt-Details

• Erscheint lt. Verlag: 7.10.2022
• Sprache: englisch
• Themenwelt: Naturwissenschaften ► Biologie ► Ökologie / Naturschutz
• Schlagworte: aquatic ecology • biological oceanography • Biologische Ozeanographie • Biowissenschaften • earth sciences • Environmental Science • Environmental Studies • Fluss • Geowissenschaften • Life Sciences • Ökologie • Ökologie / Aquatische Lebensräume • Umweltforschung • Umweltwissenschaften
• ISBN-10: 1-119-53456-9 / 1119534569
• ISBN-13: 978-1-119-53456-3 / 9781119534563