Coos Bay is an

estuary An estuary is a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it, and with a free connection to the open sea. Estuaries form a transition zone between river environments and maritime environm ...

where the

Coos River The Coos River flows for about into Coos Bay along the Pacific coast of southwest Oregon in the United States. Formed by the confluence of its major tributaries, the South Fork Coos River and the Millicoma River, it drains an important timber-p ...

enters the

Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the conti ...

, the estuary is approximately 12 miles long and up to two miles wide. It is the largest estuary completely within Oregon state lines. The Coos Bay watershed covers an area of about 600 square miles and is located in northern Coos County,

Oregon Oregon () is a U.S. state, state in the Pacific Northwest region of the Western United States. The Columbia River delineates much of Oregon's northern boundary with Washington (state), Washington, while the Snake River delineates much of it ...

in the United States. The

, which begins in the Oregon Coast Range, enters the bay from the east. From Coos River, the bay forms a sharp loop northward before arching back to the south and out to the Pacific Ocean. Haynes Inlet enters the top of this loop. South Slough branches off from the bay directly before its entrance into the

. The bay was formed when sea levels rose over 20,000 years ago at the end of the

Last Glacial Maximum The Last Glacial Maximum (LGM), also referred to as the Late Glacial Maximum, was the most recent time during the Last Glacial Period that ice sheets were at their greatest extent. Ice sheets covered much of Northern North America, Northern Eu ...

, flooding the mouth of the

. Coos Bay is Oregon's most important coastal industrial center and international shipping port, with close ties to

San Francisco San Francisco (; Spanish for " Saint Francis"), officially the City and County of San Francisco, is the commercial, financial, and cultural center of Northern California. The city proper is the fourth most populous in California and 17t ...

, the

Columbia River The Columbia River ( Upper Chinook: ' or '; Sahaptin: ''Nch’i-Wàna'' or ''Nchi wana''; Sinixt dialect'' '') is the largest river in the Pacific Northwest region of North America. The river rises in the Rocky Mountains of British Columbia ...

Puget Sound Puget Sound ( ) is a sound of the Pacific Northwest, an inlet of the Pacific Ocean, and part of the Salish Sea. It is located along the northwestern coast of the U.S. state of Washington. It is a complex estuarine system of interconnected m ...

and other major ports of the

Pacific rim The Pacific Rim comprises the lands around the rim of the Pacific Ocean. The '' Pacific Basin'' includes the Pacific Rim and the islands in the Pacific Ocean. The Pacific Rim roughly overlaps with the geologic Pacific Ring of Fire. List of ...

. The city of Coos Bay is located on the peninsula formed by the inside of the loop of the bay. Charleston is located near the entrance to South Slough. Many of the

commercial fishing Commercial fishing is the activity of catching fish and other seafood for commercial profit, mostly from wild fisheries. It provides a large quantity of food to many countries around the world, but those who practice it as an industry must oft ...

and recreational fishing boats that call Coos Bay home are docked in Charleston. North Bend, located at the apex of the peninsula, is home to the

Southwest Oregon Regional Airport Southwest Oregon Regional Airport , formerly North Bend Municipal Airport, is a public airport in North Bend, Oregon, North Bend, Coos County, Oregon, Coos County, Oregon, United States. It is operated by the Coos County Airport District. OTH cove ...

. The

has been altered over 150 years of modern anthropogenic use.

Dredging Dredging is the excavation of material from a water environment. Possible reasons for dredging include improving existing water features; reshaping land and water features to alter drainage, navigability, and commercial use; constructing d ...

, deepening, river diversion and spoil disposal has led to physical, biological, and chemical changes to the system over time.

Geology

Coos_Bay_and_Sand_Dunes_(Coos_County,_Oregon_scenic_images)_(cooD0132)

The bedrock of the greater Coos Bay region was formed from the

Mesozoic The Mesozoic Era ( ), also called the Age of Reptiles, the Age of Conifers, and colloquially as the Age of the Dinosaurs is the second-to-last era of Earth's geological history, lasting from about , comprising the Triassic, Jurassic and Cretace ...

through the

Pliocene The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.333 million to 2.58volcanic rock,

sedimentary rock Sedimentary rocks are types of rock that are formed by the accumulation or deposition of mineral or organic particles at Earth's surface, followed by cementation. Sedimentation is the collective name for processes that cause these particles ...

, and

igneous rock Igneous rock (derived from the Latin word ''ignis'' meaning fire), or magmatic rock, is one of the three main rock types, the others being sedimentary and metamorphic. Igneous rock is formed through the cooling and solidification of magma o ...

intrusions. The area's geologic history is highlighted by tectonic interaction between oceanic and continental plates.

Subduction Subduction is a geological process in which the oceanic lithosphere is recycled into the Earth's mantle at convergent boundaries. Where the oceanic lithosphere of a tectonic plate converges with the less dense lithosphere of a second plate, ...

and abduction of the oceanic plate with the

North American Plate The North American Plate is a tectonic plate covering most of North America, Cuba, the Bahamas, extreme northeastern Asia, and parts of Iceland and the Azores. With an area of , it is the Earth's second largest tectonic plate, behind the Paci ...

has led to a thicker crust in Southwestern Oregon. The

Empire Formation The Empire Formation is a geologic formation in Oregon. It preserves fossils dating back to the Neogene period Period may refer to: Common uses * Era, a length or span of time * Full stop (or period), a punctuation mark Arts, entertainment, ...

, on which Coos Bay lies, is mainly composed of sedimentary rock created by marine sediments that were deposited offshore before being pushed onshore over millions of years. This process results in the oldest rock being furthest east. East of the bay, and in the

watershed, the bedrock is the oldest, formed during the

Eocene The Eocene ( ) Epoch is a geological epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period in the modern Cenozoic Era. The name ''Eocene'' comes from the Ancient Greek (''ēṓs'', ...

. The center of Coos Bay, where the towns of North Bend and Coos Bay sit, was formed during the late

Pliocene The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.333 million to 2.58Pleistocene The Pleistocene ( , often referred to as the ''Ice age'') is the geological Epoch (geology), epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fina ...

. The North Spit, the most western area bordering the ocean, is composed of

sand dunes A dune is a landform composed of wind- or water-driven sand. It typically takes the form of a mound, ridge, or hill. An area with dunes is called a dune system or a dune complex. A large dune complex is called a dune field, while broad, fl ...

. These formed much more recently as sand was deposited along the coast after eroding from other areas. By studying the transition from peaty to muddy intertidal sediment and the associated microfossils in the estuary, researchers were able to determine 10 instances of sudden rises in sea level as a potential proxy for

earthquake An earthquake (also known as a quake, tremor or temblor) is the shaking of the surface of the Earth resulting from a sudden release of energy in the Earth's lithosphere that creates seismic waves. Earthquakes can range in intensity, fr ...

s, including two dating 1,700 and 2,300 years ago when sea level rose by at least half a meter. This same study also found evidence of a large earthquake 300 years ago along the great plate boundary. In addition, sea level rise 20,000 years ago drowned the prior river mouth, creating Coos Bay estuary as we know today.

Physical Geography

Tidal Flats

Tidal flats are areas where sediments that are deposited from rivers and tides accumulate. Coos Bay is primarily made up of mud and sand flats that form in areas of low tidal activity. The estuary covers 10,973 acres at mean high water and 5,810 acres at mean low water, and about 48% of the watershed is tideland. Tidal effects can extend up the tributaries 27 miles from the ocean. Of the tidal flats in Coos Bay estuary, organic content is highest in the

mudflat Mudflats or mud flats, also known as tidal flats or, in Ireland, slob or slobs, are coastal wetlands that form in intertidal areas where sediments have been deposited by tides or rivers. A global analysis published in 2019 suggested that tidal f ...

s (8-18% of dry weight, 19.77 ppt) compared to the sandflats (1-2% of dry weight, <0.1 ppt). These areas tend to lack visible vegetation, but do support benthic

diatom A diatom ( Neo-Latin ''diatoma''), "a cutting through, a severance", from el, διάτομος, diátomos, "cut in half, divided equally" from el, διατέμνω, diatémno, "to cut in twain". is any member of a large group comprising se ...

s, mats of

green Green is the color between cyan and yellow on the visible spectrum. It is evoked by light which has a dominant wavelength of roughly 495570 nm. In subtractive color systems, used in painting and color printing, it is created by a combin ...

and yellow green algae, and eelgrass beds (

Zostera marina ''Zostera marina'' is a flowering vascular plant species as one of many kinds of seagrass, with this species known primarily by the English name of eelgrass with seawrack much less used, and refers to the plant after breaking loose from the subme ...

and Z. japonica). Tidal flats in the estuary have a network of shallow channels that allow water to drain when the flats are above water, and when submerged, allow water and sediment to pass through the flats. In this way, the flats act as a barrier that slows the water passing through, reduces how much water can flow through, and encourages the deposition, re-suspension, and transport of particles with the tides as the flats are constantly experiencing deposition and erosion. The

s are primarily made of a mix of medium and fine-grained sands, silts, and clays, while the sandflats are primarily made of medium-sized sand grains derived from the erosion of the nearby cliffs. The higher organic content of mudflats is composed of plant and animal tissues and wastes, diatoms, bacteria, and flocculants, chemicals that pull suspended particles out of the water to form into sediment. The environment a few centimeters below the sediment doesn't have enough oxygen, so sulfate-reducing bacteria live there, breaking down organic matter and producing

hydrogen sulfide Hydrogen sulfide is a chemical compound with the formula . It is a colorless chalcogen-hydride gas, and is poisonous, corrosive, and flammable, with trace amounts in ambient atmosphere having a characteristic foul odor of rotten eggs. The under ...

, giving the mudflats the classic "rotten egg" smell.

Weather

The mild marine climate of Coos Bay is classified as Csb or a Temperate Mediterranean Climate zone and is heavily influenced by the Pacific Ocean and precipitation from the Coast Range. Regional weather consists of a cool, wet season in the winter (October through April) with an average annual rainfall of 56 inches, and a mild, dry season in the summer (May through September) with an average rainfall of less than 4 inches. Runoff follows this same pattern, with approximately one month of lag. Air temperatures range from 40° to 75 °F. Winter storms lead to accumulation of winter precipitation and which is a significant input of fresh water and sediments.

Fluvial Geomorphology

Fluvial geomorphology is the study of the way rivers move through and affect their surrounding landscape. For an estuary, this involves the tributaries and their flow rates, bottom topography, water discharge and the drainage basin, and sedimentation and deposition.

Tributaries

Thirty tributaries enter the bay, including 13 freshwater sources, the

being the largest freshwater source. About 1 m³/s of freshwater is released by the Coos River into the estuary in the summer and >300 m³/s in the winter. These waters travel through areas of heavy logging and limited agriculture, originating from the Coastal Range. The main channel of the estuary follows the north–south trending

anticline In structural geology, an anticline is a type of fold that is an arch-like shape and has its oldest beds at its core, whereas a syncline is the inverse of an anticline. A typical anticline is convex up in which the hinge or crest is t ...

(an arch-like fold in the ground), ending in the Isthmus Slough, Catching Slough, Haynes Inlet, and Coos River; while southward, the South Slough follows the

syncline In structural geology, a syncline is a fold with younger layers closer to the center of the structure, whereas an anticline is the inverse of a syncline. A synclinorium (plural synclinoriums or synclinoria) is a large syncline with superimpose ...

(an inward curve in the ground). The sediment accumulation rate is approximately 2.3–9 mm/yr in a 0.9-m deep flat in South Slough over a 300-year timescale. This is greater than the sea level is expected to rise locally, 1.10 ± 0.73 mm/yr.

Bottom Topography

Coos Bay is considered
drowned river valley estuary
meaning it was a river valley that was flooded as sea levels rose. The shallow and narrow "V"-shaped topography of Coos Bay is more varied across the channel than it is longitudinally. It is deepest near the mouth of the estuary, where the bottom is uniform, and the slope leading to this decline is gentle. This topography, coupled with high tidal range and low runoff, allows for lateral and vertical mixing.

Water Discharge and Drainage Basin

Annually, Coos Bay is estimated to discharge 2.2 million acre-feet of fresh water, with a yearly maximum of 3,044,000 ac-ft and a minimum of 1,560,000 ac-ft, based on extrapolations of fresh water inflow measured at the West Fork of the

Millicoma River __NOTOC__ The Millicoma River is a coast stream, about long, east of Coos Bay in the U.S. state of Oregon. Formed by the confluence of the East Fork Millicoma River and the West Fork Millicoma River at Allegany, it meanders across relatively flat ...

mouth in 1974. According to a

US Department of Commerce The United States Department of Commerce is an executive department of the U.S. federal government concerned with creating the conditions for economic growth and opportunity. Among its tasks are gathering economic and demographic data for bus ...

survey from 1954 to 1970, freshwater inflow enters the estuary at a rate of 90 cubic feet per second (cfs) in the summer and 5500 cfs in the winter with an average of 2200 cfs. The drainage basin consists of forest, cropland, and rangelands. The South Slough watershed alone has a drainage area of about 7,932 ha.

Sedimentation and Deposition

As of 1975, the Coos Bay has experienced a greater influx of sediment than output. Such sediment includes silt from drainage basin

erosion Erosion is the action of surface processes (such as water flow or wind) that removes soil, rock, or dissolved material from one location on the Earth's crust, and then transports it to another location where it is deposited. Erosion is d ...

, and various sands (marine sand, dune sand, South Slough cliff sand) due to erosion in the surrounding areas. Sediments are formed and moved via streams, littoral drift, or transport of sediments along a coastline parallel to the shore, processes due to wind activity, and erosion. Sediment grains increase in size with depth and decrease in size when moving further into the estuary, likely because tidal currents are less strong further in and can no longer carry larger particles. To keep the estuary fit as a navigation channel, an average of 1.65 million square yards of material was removed annually by the

US Army Corps of Engineers , colors = , anniversaries = 16 June (Organization Day) , battles = , battles_label = Wars , website = , commander1 = ...

prior to the start of the Deep-Draft Navigation Project. Sediments input averages 72,000 tons annually. Modeling of Coos Bay sediment movement compared to historical patterns reveals that suspended-sediment concentrations and sediment retention has increased in the estuary over time as dredging, river diversion, construction and spoils disposal continues. As a result of this development, sediment transport has been diverted into the central navigation channel, where more sediment is accumulating. Tidal flat sediment retention has also increased.

Biogeochemistry

Tides & Upwelling

Seasonal winds cause tides and

upwelling Upwelling is an physical oceanography, oceanographic phenomenon that involves wind-driven motion of dense, cooler, and usually nutrient-rich water from deep water towards the ocean surface. It replaces the warmer and usually nutrient-depleted ...

that influence nutrients and the biogeochemistry of Coos Bay estuary. One third of macrophyte production in the estuary is attributed to upwelling. In the summer, wind primarily comes from the North along the Oregon coast, bringing up nutrient-rich deep water and boosting

primary production In ecology, primary production is the synthesis of organic compounds from atmospheric or aqueous carbon dioxide. It principally occurs through the process of photosynthesis, which uses light as its source of energy, but it also occurs through ...

. Strong tides then move these upwelled nutrients further upstream, which stimulates primary production in the estuary. Oregon experiences mixed

semi-diurnal A diurnal cycle (or diel cycle) is any pattern that recurs every 24 hours as a result of one full rotation of the planet Earth around its axis. Earth's rotation causes surface temperature fluctuations throughout the day and night, as well as ...

tides, meaning there are two high and two low tides per day which differ in height. In 2000, the difference in semi-diurnal high and low tides was on average 0.3-0.5 m, and the average tidal amplitude between Mean Higher High Water and Mean Lower Low Water was about 2.1 m. The

tidal prism A tidal prism is the volume of water in an estuary or inlet between mean high tide and mean low tide,Luketina, D. 1998. Simple tidal prism models revisited. Estuarine, Coastal and Shelf Science; Vol. 46. pp. 77–84. or the volume of water leavin ...

, or the amount of water between mean high tide and mean low tide, accounts for 30% of the estuary's volume. Estuary mixing and stratification is dependent on the tidal flux and river flux. Circulation patterns are also tidally-influenced. In the summer, the estuary is well-mixed, but in the winter it is highly stratified. Furthermore, in the summer months saltwater influence is greater as freshwater flow into the estuary is minimal. Following anthropogenic deepening and widening, the estuary has a 33% greater mean tidal amplitude and 18% more salinity intrusion length.

Nutrients

Nitrogen inputs vary seasonally and along the salinity gradient. Increased precipitation during the wet season is a major input of land-based nitrogen, as is the watershed associated with agricultural nitrogen runoff and

red alder ''Alnus rubra'', the red alder, is a deciduous broadleaf tree native to western North America (Alaska, Yukon, British Columbia, Washington, Oregon, California, Idaho and Montana). Description Red alder is the largest species of alder in ...

nitrogen fixation Nitrogen fixation is a chemical process by which molecular nitrogen (), with a strong triple covalent bond, in the air is converted into ammonia () or related nitrogenous compounds, typically in soil or aquatic systems but also in industry. Atmo ...

. Oregon Coast Range streams typically contain higher amounts of nitrate compared to other Pacific Northwest streams due to the healthy population of red alder trees capable of fixing nitrogen. During the dry season, the major input of nitrogen comes from the ocean following upwelling events bringing nutrients like nitrogen into the estuary. In the late summer and fall, nitrate concentrations measured at low tide are varied, with highest concentrations in the tidal regions of the estuary, and lowest at the riverine ends. In the winter, during peak freshwater inputs, nitrate concentrations are high and fairly uniform throughout the estuary. This indicates that in the dry season, nutrient sources come from the Ocean, while in the wet season, nutrients are coming in with the freshwater. During summer months when dry conditions persist and upwelling is occurring, the primary source of phosphorus is from the ocean. Thus, phosphorus concentrations also vary depending on location in the estuary, on the ocean end or riverine end.

Chemistry

Roughly half of the total organic matter within the Coos Bay estuary is stored organic carbon within sediments. Clay and silt particles typically have the highest concentrations of organic matter associated with them.

Photosynthesis Photosynthesis is a process used by plants and other organisms to convert light energy into chemical energy that, through cellular respiration, can later be released to fuel the organism's activities. Some of this chemical energy is stored in ...

by primary producers draws down atmospheric carbon dioxide and eventual burial of primary producers such as eelgrass and algae lead to long term burial of carbon in estuarine sediments. Estuaries can provide an important sink for increasing global carbon dioxide concentrations as estuary sediments can store carbon rapidly depending on tidal fluxes. Similar to nitrogen and phosphorus,

chlorophyll Chlorophyll (also chlorophyl) is any of several related green pigments found in cyanobacteria and in the chloroplasts of algae and plants. Its name is derived from the Greek words , ("pale green") and , ("leaf"). Chlorophyll allow plants to ...

is dependent on upwelling and tidal mixing and varies along the salinity gradient. These physical processes influence estuarine

by either directly transporting chlorophyll associated with plants from coastal waters into the estuary or by transporting recently upwelled, nutrient rich water, into the estuary which triggers primary production. Temperature, salinity, and dissolved oxygen levels vary according to wind forcing, river discharge and tides, with a variety of timescales from daily (tidal) to yearly. These values '' mbiguous' and pH are also monitored at various locations throughout South Slough. In the wet winter season (December - February), the bottom water measured in the tidal waters of South Slough at Valino Island tends to be relatively cold, with temperatures ranging from 5° to 11 °C and highly variable salinity (0-20 psu). In the spring (March–May), temperatures increase to 13° to 23 °C and salinity becomes more stabilized (27 ± 4 psu) due to is less freshwater input. During the dry summer season (June - August), bottom temperatures increase to around 15 °C and salinity increases with less variability (31 ± 3 psu). In the fall (September - November) temperatures drop and salinity becomes more variable (30 ± 5 psu). Similar patterns are expected throughout the estuary, although location within the estuary will alter dynamics and values. Seasonal variations of dissolved oxygen include relative highs in the fall and winter (Dec - Jan; >8 mg L⁻¹) with fluctuations across the estuary and lows in the spring and summer during the upwelling season (Apr - Sep; close to 5 mg L⁻¹), with some variation. Lowest dissolved oxygen levels are found in the mouth in the spring and at the riverine end in late summer and early fall. While upwelling does bring oxygen-poor water to the surface, upwelling strength alone is not a good predictor of low dissolved oxygen levels; the influence of other physical and biological factors are also needed to explain patterns of oxygen concentration. Overall, there is minimal likelihood of hypoxia due to rapid tidal exchange and shallow waters, based on the established dissolved oxygen content of the estuary throughout the year. South Slough did not exhibit any distinct seasonal pattern in pH at any of the monitoring sites, instead remaining within 7.5 and 8.2 year round at Valino Island. pH tends to be lower in the more riverine locations, between 6.5 and 7.8. However, there were strong daily fluctuations in pH following the tides and daylight at all monitoring sites, as shown by strong correlation with conductivity and salinity. Generally, levels of nutrients, salinity, specific conductivity and chlorophyll are at healthy levels in the estuary, as are water temperature, oxygen, and pH.

Pollution

Historically, Coos Bay has been subject to a range of

pollutant A pollutant or novel entity is a substance or energy introduced into the environment that has undesired effects, or adversely affects the usefulness of a resource. These can be both naturally forming (i.e. minerals or extracted compounds like o ...

s from different sources from logging mills, boat manufacturing, and runoff. The area is also particularly vulnerable to any oil or chemical spills at the International

Port of Coos Bay The Oregon International Port of Coos Bay is a port of the Pacific coast of the United States, located in Coos Bay near the city of Coos Bay, Oregon. It is the largest deep-draft coastal harbor between San Francisco Bay and Puget Sound, and is Or ...

, due to its strong tidal currents. The Oregon Department of Environmental Quality (DEQ) began collecting samples of pollutions and contaminants in the late 1990s, and found that one of the largest sources of pollution into the Coos Bay estuary had been from

tributyltin Tributyltin (TBT) is an umbrella term for a class of organotin compounds which contain the (C4H9)3 Sn group, with a prominent example being tributyltin oxide. For 40 years TBT was used as a biocide in anti-fouling paint, commonly known as bott ...

(TBT) sourced from two active shipyards within the estuary. TBT became an environmental concern in the late 1980s after commercial oyster farmers began noticing shell deformities. After sample results showed toxic levels of TBT, the two shipyards worked with the DEQ to clean up contaminated sediments and implement more environmentally conscience practices, which allowed Coos Bay to avoid being listed as a

superfund Superfund is a United States federal environmental remediation program established by the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA). The program is administered by the Environmental Protection Agency ...

site. Southeast of Coos Bay is one of the state's largest coal fields with an area of 250 sq miles. Groundwater seepage from this coal field historically has also been a source of pollution.

Ecology and Biology

Plant life

Plant life in Coos Bay supports biodiverse ecosystems contained within this watershed, ranging from forests in the uplands to eelgrass meadows in the bay. The forested regions of Coos Bay have been logged at least once in the past century, and some of these areas were replanted solely with

Douglas fir The Douglas fir (''Pseudotsuga menziesii'') is an evergreen conifer species in the pine family, Pinaceae. It is native to western North America and is also known as Douglas-fir, Douglas spruce, Oregon pine, and Columbian pine. There are three v ...

trees.

Sitka spruce ''Picea sitchensis'', the Sitka spruce, is a large, coniferous, evergreen tree growing to almost tall, with a trunk diameter at breast height that can exceed 5 m (16 ft). It is by far the largest species of spruce and the fifth-lar ...

, western hemlock, and

Port Orford cedar ''Chamaecyparis lawsoniana'', known as Port Orford cedar or Lawson cypress, is a species of conifer in the genus '' Chamaecyparis'', family Cupressaceae. It is native to Oregon and northwestern California, and grows from sea level up to in the ...

trees can also be found in Coos Bay watershed, ranging from 15- to 75-years of age. Key upland area plant life also include evergreen huckleberry, Pacific sword fern, salal and

salmonberry ''Rubus spectabilis'', the salmonberry, is a species of bramble in the rose family Rosaceae, native to the west coast of North America from west-central Alaska to California, inland as far as Idaho. Like many other species in the genus ''Rubus'' ...

. Fresh and tidal marsh plants include baltic rush, fleshy jaumea, Lyngby's sedge, Pacific silverweed,

pickleweed Pickleweed is a common name used for two unrelated genera of flowering plants: *'' Batis'', family Bataceae *''Salicornia ''Salicornia'' is a genus of succulent, halophytic (salt tolerant) flowering plants in the family Amaranthaceae that grow ...

, salt grass, seaside arrowgrass,

skunk cabbage Skunk cabbage is a common name for several plants and may refer to: * the genus '' Lysichiton'' ** Asian skunk cabbage, ''Lysichiton camtschatcensis'', grows in eastern Asia ** Western skunk cabbage, ''Lysichiton americanus'', grows in western Nor ...

, Slough sedge, salt-marsh bird's beak, western bog lily, and

tufted hairgrass ''Deschampsia cespitosa'', commonly known as tufted hairgrass or tussock grass, is a perennial tufted plant in the grass family Poaceae. Distribution of this species is widespread including the eastern and western coasts of North America, parts o ...

Eelgrass

In the aquatic regions, eelgrass (''

'' and ''

Zostera japonica ''Zostera japonica'' is a species of aquatic plant in the Zosteraceae family. It is referred to by the common names dwarf eelgrass or Japanese eelgrass, and is native to the seacoast of eastern Asia from Russia to Vietnam, and introduced to the w ...

'') covers about 1,400 acres of Coos Bay. Eelgrass beds are a vital habitat to many species of invertebrates. Additionally, the eelgrass affects the flow of water through the area, stabilizes the sediment, exchanges nutrients between the water column and sediments, and is a source of food for consumers. The beds provide cover for predators and prey alike, including ecologically or economically important fish (see Fish section below). Eelgrasses are clearly important to the ecosystem, but they are also vulnerable to disruption. During a study in 1996, the density of eelgrass (''Zostera marina'') plants decreased by 59.4% over a period of 75 days on plots undergoing mariculture of Pacific oysters compared to only a 28.8% reduction in the control plots. The ''Z. marina'' also decreased in spatial cover under treatment conditions, by 70.7% in high elevations and 36.7% in lower intertidal regions of the study. Following removal of these mariculture practices, ''Z. marina'' beds struggled to recover, and recovery depended most on how many ''Z. marina'' plants there were at the start of recovery, rather than on new growth. However, transplanted ''Z. marina'' did recover better than plots left to recover on their own. Aside from anthropogenic influences, eelgrass is also affected by other factors. A study on ''Z. marina'' meadows in Coos Bay from 1998 to 2001 found that ''Z. marina'' is more dense in areas with higher salinity and lower temperature; gradients which vary within the estuary depending on location. Over the course of the study, which includes the transition from El Niño to La Niña, leading to warmer winters and cooler summers, eelgrass density, biomass, and flowering all increased. Japanese eelgrass (''Zostera japonica'') is an invasive species, likely introduced during commercial oyster cultivation in 1970 or earlier. The distribution of ''Z. japonica'' has spread from the upper reaches of South Slough in the 1970s into the middle region of the estuary by 1987. By the early 1980s it is everywhere in the estuary, most commonly in the mid intertidal zone. ''Z. japonica'' converts unvegetated mudflats into eelgrass beds, leading to significant changes in the species composition and abundance of invertebrate communities of the area. Overall, species richness was significantly higher in ''Z. japonica'' dominated areas than it was before the invasion.

Algae

A variety of algae can be found in Coos Bay. Micro-algae or

Phytoplankton Phytoplankton () are the autotrophic (self-feeding) components of the plankton community and a key part of ocean and freshwater ecosystems. The name comes from the Greek words (), meaning 'plant', and (), meaning 'wanderer' or 'drifter'. ...

, such as

s, are abundant. Coos Bay has some of the highest primary productivity within west coast estuaries. In the lower part of the bay, species such as ''

Chaetoceros ''Chaetoceros'' is probably the largest genus of marine planktonic diatoms with approximately 400 species described, although many of these descriptions are no longer valid. It is often very difficult to distinguish between different ''Chaeto ...

'', '' Skeletonema'', and ''

Thalassiosira ''Thalassiosira'' is a genus of centric diatoms, comprising over 100 marine and freshwater species. It is a diverse group of photosynthetic eukaryotes that make up a vital part of marine and freshwater ecosystems, in which they are key primary pr ...

'' are found. In the upper part of the bay, species such as ''

Melosira ''Melosira'' is a genus of diatoms belonging to the family Melosiraceae. The genus has cosmopolitan distribution In biogeography, cosmopolitan distribution is the term for the range of a taxon that extends across all or most of the world i ...

'' and ''Skeletonema'' are found. As of 1973,

zooplankton Zooplankton are the animal component of the planktonic community ("zoo" comes from the Greek word for ''animal''). Plankton are aquatic organisms that are unable to swim effectively against currents, and consequently drift or are carried along by ...

were most abundant near the ocean, and numbers tended to decrease further into the bay. Neritic (swimming) species were found in the lower parts of the estuary. In a typical year, there is a small bloom of

s in the late winter and early spring before heavy grazing pressure by the zooplankton limits overall abundance. Lack of sunlight limits diatom growth in the fall and winter. Most algae are found at the mouth of the bay, and notably there is a shift in species from marine to brackish water plants here. Kelp beds, specifically those of bull kelp ( ''Nereocystis leutkeana''), are found in the bay as well.

Fish

Coos Bay provides habitat for both residential and anadromous fish. The South Slough is an essential nursery environment for many marine fish in their larval and juvenile life stages. Near the mouth of the bay,

perch Perch is a common name for fish of the genus ''Perca'', freshwater gamefish belonging to the family Percidae. The perch, of which three species occur in different geographical areas, lend their name to a large order of vertebrates: the Per ...

sculpin A sculpin is a type of fish that belongs to the superfamily Cottoidea in the order Scorpaeniformes.Kane, E. A. and T. E. Higham. (2012)Life in the flow lane: differences in pectoral fin morphology suggest transitions in station-holding demand ...

, and rockfish are found. Surveys in the South Slough, the most commonly studied portion of Coos Bay, have shown that

Shiner perch The shiner perch (''Cymatogaster aggregata'') is a common surfperch found in estuaries, lagoons, and coastal streams along the Pacific coast from Alaska to Baja California. It is the sole member of its genus. The shiner perch is also known as se ...

are the most abundant fish in the estuary. Shiner perch comprise 76% of fish caught by seine, and typically have a strong association with the eelgrass beds. Staghorn sculpin are another dominant species. Many of the residential species, Shiner perch included, move into the tidal flats during flood tides. Overall, the fish biomass abundance decreases with increasing distance from the ocean.

Coho salmon The coho salmon (''Oncorhynchus kisutch;'' Karuk: achvuun) is a species of anadromous fish in the salmon family (biology), family and one of the five Pacific salmon species. Coho salmon are also known as silver salmon or "silvers". The scientif ...

Chinook salmon The Chinook salmon (''Oncorhynchus tshawytscha'') is the largest and most valuable species of Pacific salmon in North America, as well as the largest in the genus '' Oncorhynchus''. Its common name is derived from the Chinookan peoples. Other ...

, Steelhead,

Coastal cutthroat trout The coastal cutthroat trout (''Oncorhynchus clarkii clarkii''), also known as the sea-run cutthroat trout, blue-back trout or harvest trout, is one of the several subspecies of cutthroat trout found in Western North America. The coastal cutthroa ...

Striped bass The striped bass (''Morone saxatilis''), also called the Atlantic striped bass, striper, linesider, rock, or rockfish, is an anadromous perciform fish of the family Moronidae found primarily along the Atlantic coast of North America. It has ...

Pacific lamprey The Pacific lamprey (''Entosphenus tridentatus'') is an anadromous parasitic lamprey from the Pacific Coast of North America and Asia. It is a member of the Petromyzontidae family. The Pacific lamprey is also known as the three-tooth lamprey and ...

s, Western brook lampreys and

American shad The American shad (''Alosa sapidissima'') is a species of anadromous clupeid fish naturally distributed on the North American coast of the North Atlantic, from Newfoundland to Florida, and as an introduced species on the North Pacific coast. Th ...

all migrate through Coos Bay during different times of the year. The Coos Bay estuary provides critical habitat for many of the juveniles of these species that have migrated upriver to spawn. Historically,

White sturgeon White sturgeon (''Acipenser transmontanus'') is a species of sturgeon in the family Acipenseridae of the order Acipenseriformes. They are an anadromous fish species ranging in the Eastern Pacific; from the Gulf of Alaska to Monterey, California. ...

Green sturgeon The green sturgeon (''Acipenser medirostris'') is a species of sturgeon native to the northern Pacific Ocean, from China and Russia to Canada and the United States. Description Sturgeons are among the largest and most ancient of ray finn ...

, and

Chum Salmon The chum salmon (''Oncorhynchus keta''), also known as dog salmon or keta salmon, is a species of anadromous salmonid fish from the genus '' Oncorhynchus'' (Pacific salmon) native to the coastal rivers of the North Pacific and the Beringian A ...

could also be found in Coos Bay.Oregon Department of Fish and Wildlife; Citizen Advisory Committee (1990).
Coos River Basin Fish Management Plan
(PDF). University of Oregon. p. 7. Retrieved November 9, 2022

Shellfish

Some of Oregon's most productive shellfishing is in Coos Bay. Coos Bay is Oregon's largest bay, and the lower part of the bay offers many shellfishing opportunities such as crabbing and clamming. The lower bay is the area that extends from the airport to the ocean entrance, and is marine dominated (meaning there is little freshwater influence). Some popular, easily accessible clamming spots are along Cape Arago highway, where recreational clammers can dig for gaper and butter clams, in the extensive mud flats during low tide. Gaper, Cockle,

Butter Butter is a dairy product made from the fat and protein components of churned cream. It is a semi-solid emulsion at room temperature, consisting of approximately 80% butterfat. It is used at room temperature as a spread, melted as a condim ...

, Littleneck, Razor and Softshell Clams have all been found in the bay. Various species of clams were commercially harvested up to 1985.

Dungeness crab The Dungeness crab (''Metacarcinus magister'') is a species of crab inhabiting eelgrass beds and water bottoms along the west coast of North America. It typically grows to across the carapace and is a popular seafood. Its common name comes from ...

are also frequently caught by recreational fishermen inside the bay. Ghost and mud shrimp are also found in the tidal flats and are harvested by both recreational and commercial fishermen for use as bait. In the South Slough, Polychaetes (e.g. annelid worms) comprise 38% of the genera found, making them the most diverse in the ecosystem. In contrast, Decapods (e.g. crabs) comprise only 16%, and

Bivalves Bivalvia (), in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class of marine and freshwater molluscs that have laterally compressed bodies enclosed by a shell consisting of two hinged parts. As a group, bival ...

(e.g. clams) only 13%. Generally, species composition decreases with increasing distance from the ocean. Beaver-Szmurlo

Wildlife

Mallard Ducks, Pintail Ducks, Widgeon, Marbled murrelet, and

Coot Coots are medium-sized water birds that are members of the rail family, Rallidae. They constitute the genus ''Fulica'', the name being the Latin term for "coot". Coots have predominantly black plumage, and—unlike many rails—they are usually ...

all live in the estuaries. The more migratory species of Canvasback ducks, Pintail ducks, and Black Brant winter in the estuaries. Many of the

seabird Seabirds (also known as marine birds) are birds that are adapted to life within the marine environment. While seabirds vary greatly in lifestyle, behaviour and physiology, they often exhibit striking convergent evolution, as the same envir ...

s typically found along Oregon's coast such as

pelican Pelicans (genus ''Pelecanus'') are a genus of large water birds that make up the family Pelecanidae. They are characterized by a long beak and a large throat pouch used for catching prey and draining water from the scooped-up contents before ...

s and

gull Gulls, or colloquially seagulls, are seabirds of the family Laridae in the suborder Lari. They are most closely related to the terns and skimmers and only distantly related to auks, and even more distantly to waders. Until the 21st century ...

s can also be seen in the bay.

Seals Seals may refer to: * Pinniped, a diverse group of semi-aquatic marine mammals, many of which are commonly called seals, particularly: ** Earless seal, or "true seal" ** Fur seal * Seal (emblem), a device to impress an emblem, used as a means of a ...

and

sea lion Sea lions are pinnipeds characterized by external ear flaps, long foreflippers, the ability to walk on all fours, short and thick hair, and a big chest and belly. Together with the fur seals, they make up the family Otariidae, eared seals. ...

s can typically be seen in the marine dominated zones. River otters can be found further up in the estuary. The fresh and tidal marshes are home to American beavers.

Roosevelt elk The Roosevelt elk (''Cervus canadensis roosevelti)'', also known commonly as the Olympic elk and Roosevelt's wapiti, is the largest of the four surviving subspecies of elk (''Cervus canadensis'') in North America by body mass (although by antl ...

live in the uplands.

Tidal Marshes

Tidal marsh A tidal marsh (also known as a type of "tidal wetland") is a marsh found along rivers, coasts and estuaries which floods and drains by the tidal movement of the adjacent estuary, sea or ocean. Tidal marshes are commonly zoned into lower marshes ( ...

es are

marsh A marsh is a wetland that is dominated by herbaceous rather than woody plant species.Keddy, P.A. 2010. Wetland Ecology: Principles and Conservation (2nd edition). Cambridge University Press, Cambridge, UK. 497 p Marshes can often be found ...

es that are found along the coast and experience regular tidal flooding and draining. They are important because they provide protection against

storm surges A storm surge, storm flood, tidal surge, or storm tide is a coastal flood or tsunami-like phenomenon of rising water commonly associated with low-pressure weather systems, such as cyclones. It is measured as the rise in water level above the no ...

, reduce

, improve water quality, support a biodiverse ecosystem, and provide opportunities for recreation, which boosts the local economy. The resilience of a

tidal marsh A tidal marsh (also known as a type of "tidal wetland") is a marsh found along rivers, coasts and estuaries which floods and drains by the tidal movement of the adjacent estuary, sea or ocean. Tidal marshes are commonly zoned into lower marshes ( ...

depends on the vegetation types and their location in the tidal frame, exposure to stressors, surrounding land use, and if there is enough space for migration. The soils of tidal marshes tend to be salty and hypoxic, with vegetation adapted for regular precipitation and tidal flooding. These areas are especially vulnerable to changes in these systems, especially rising sea levels. The

National Oceanic and Atmospheric Administration The National Oceanic and Atmospheric Administration (abbreviated as NOAA ) is an United States scientific and regulatory agency within the United States Department of Commerce that forecasts weather, monitors oceanic and atmospheric conditi ...

and the

National Estuarine Research Reserve System The National Estuarine Research Reserve System is a network of 29 protected areas established by partnerships between the National Oceanic and Atmospheric Administration (NOAA) and coastal states. The reserves represent different biogeographic re ...

work together to assess the resilience of tidal marshes around the country and provide recommendations for their management and conservation. Coos Bay is composed of several types of tidal marshes, according to reports from 1974, 1979, and 2021: The low sand marsh is mainly

sand Sand is a granular material composed of finely divided mineral particles. Sand has various compositions but is defined by its grain size. Sand grains are smaller than gravel and coarser than silt. Sand can also refer to a textural class ...

y, but may have

silt Silt is granular material of a size between sand and clay and composed mostly of broken grains of quartz. Silt may occur as a soil (often mixed with sand or clay) or as sediment mixed in suspension with water. Silt usually has a floury feel ...

and mud. This marsh type gently slopes at the edges into the surrounding area. Commonly found plants include

Pickleweed Pickleweed is a common name used for two unrelated genera of flowering plants: *'' Batis'', family Bataceae *''Salicornia ''Salicornia'' is a genus of succulent, halophytic (salt tolerant) flowering plants in the family Amaranthaceae that grow ...

, Seaside arrowgrass, Desert saltgrass, Three-Square rush, ''Jaumea'', Dwarf hairgrass,

Sea plantain ''Plantago maritima'', the sea plantain, seaside plantain or goose tongue, is a species of flowering plant in the plantain family Plantaginaceae. It has a subcosmopolitan distribution in temperate and Arctic regions, native to most of Europe, ...

, Paintbrush orthocarpus, ''

Glaux maritima ''Lysimachia maritima'' is a plant species belonging to the family Primulaceae. It was previously called ''Glaux maritima'', the only species in the monotypic genus ''Glaux''. The species has a number of common names, including sea milkwort, sea ...

'', '' Carex lyngbyei'', and

Tufted hairgrass ''Deschampsia cespitosa'', commonly known as tufted hairgrass or tussock grass, is a perennial tufted plant in the grass family Poaceae. Distribution of this species is widespread including the eastern and western coasts of North America, parts o ...

. The low silt marsh is generally silty and muddy and is lacking in channels for tidal drainage. Commonly found plants include ''Triglochin maritirh, Scirpus robustus, Carex, Jaumea,

Spergularia Spergularia is a genus in the family Caryophyllaceae, containing salt-tolerant plants known as sandspurrys and sea-spurreys. There are about 60 species. Selected species * '' Spergularia azorica'' – endemic to the archipelago of the AzoresSe ...

, Juncus lescurii,'' and '' Cotula coronopifolia.'' The sedge marsh is composed of low and high marshes which are likely to have diffuse tidal drainage and channels up to four feet high, respectively. Commonly found plants include ''Carex lynghyei, Triglochin,

Deschampsia caespitosa ''Deschampsia cespitosa'', commonly known as tufted hairgrass or tussock grass, is a perennial tufted plant in the grass family Poaceae. Distribution of this species is widespread including the eastern and western coasts of North America, parts o ...

,'' and ''Hordeum nodosum''. The immature high marsh is easily identified as it is flat and sits a few feet above the surrounding mudflats. The immature high marsh also has deep channels that drain it. Commonly found plants include ''Carex, Deschampsia, Hordeum, Juncus lesccurii, Potentilla pacifica, Distichlis, Artiplex natula,'' and '' Agrostis alba''. The mature high marsh is typically higher than the immature high marsh and it contains underground drainage channels. Commonly found plants include '' Remex occidentalis, Grindelia stricta, Trifolium wormskjoldii, Vicia gigantea,'' and ''

Lathyrus japonicus ''Lathyrus japonicus'', the sea pea, beach pea, circumpolar pea or sea vetchling, is a species of flowering plant in the legume family Fabaceae, native to temperate coastal areas of the Northern Hemisphere and Argentina. It is a herbaceous pere ...

''. The bulrush-sedge marsh is typically found on the banks of a river or slough, particularly one with freshwater. Commonly plants include ''Scirpus validus'' and ''Carex lyngbyei''. The diked marsh has broad variability as this is not a "natural" type of marsh. Instead, it is formed when saltwater is cut off from entering the former marsh. Most marshes found in Coos Bay were likely high or immature high marshes, before they were diked and used for pasture land. Saltwater plants, over time, will be replaced by freshwater plants. One saltwater plant that may remain is ''Juncus lescurii''. The replacement plants, however, include grasses, shrubs, buttercups, herbs, alders, and other trees. The surge plain is the result of overflowing streams that were dammed, therefore also has broad variability.

South Slough

The South Slough, a sub-basin of the Coos watershed, is particularly well studied. The South Slough National Estuarine Research Reserve, spanning 4,771 acres, was the first estuary protected by the

National Estuarine Research Reserve The National Estuarine Research Reserve System is a network of 29 protected areas established by partnerships between the National Oceanic and Atmospheric Administration (NOAA) and coastal states. The reserves represent different biogeographic r ...

in 1974. Since then, the estuary and surrounding watershed have been constantly monitored by the

and the Oregon Department of State Lands. Monitoring includes both water quality, ecosystem surveys, and measurements of resilience. The

and the

rated South Slough as more vulnerable than the national average because it's tidal range is small and most of the vegetation is below the mean tide. Additionally, most of the edges of the marsh are un-vegetated. However, South Slough was rated higher than average for adaptive capacity because there is a lot of space for marsh migration as sea levels rise; recommendations for management include protecting these surrounding areas. The diverse ecosystems that encompass the South Slough Reserve include salt marshes, eelgrass beds, sand, mud, and tidal flats, freshwater ponds and marshes, and even benthic habitats in the deep open channels.

Threats

Threats to the biodiversity of Coos Bay watershed include

invasive species An invasive species otherwise known as an alien is an introduced organism that becomes overpopulated and harms its new environment. Although most introduced species are neutral or beneficial with respect to other species, invasive species adv ...

, forest pathogens, and

wildfire A wildfire, forest fire, bushfire, wildland fire or rural fire is an unplanned, uncontrolled and unpredictable fire in an area of combustible vegetation. Depending on the type of vegetation present, a wildfire may be more specifically identi ...

. Green crabs, a species native to Europe, are invasive in Coos Bay. One of the species of eelgrass, ''Zostera japonica'', is also invasive. Through 2015, seagrass saw an increase in abundance, but Oregon State researchers have suggested that there has been a recent precipitous decline in seagrass mean density in parts of South Slough after a peak in 2015. Additionally, boats and ships have accidentally introduced terrestrial plant species such as

gorse ''Ulex'' (commonly known as gorse, furze, or whin) is a genus of flowering plants in the family Fabaceae. The genus comprises about 20 species of thorny evergreen shrubs in the subfamily Faboideae of the pea family Fabaceae. The species are ...

, English ivy,

reed canary grass ''Phalaris arundinacea'', or reed canary grass, is a tall, perennial bunchgrass that commonly forms extensive single-species stands along the margins of lakes and streams and in wet open areas, with a wide distribution in Europe, Asia, northern ...

, and ''Spartina spp''. The South Slough Research Reserve is aware of these species and, according to its 2017-2022 Management Plan, is "motivated to minimize their damaging effects early."

trees may experience swiss needle cast as a result of contracting the fungal infection '' Phaeocryptopus gaeumannii''. This results in stunted growth. Port Orford cedars and sometimes Pacific yews contract

root rot Root rot is a condition in which anoxic conditions in the soil or potting media around the roots of a plant cause them to rot. This occurs due to excessive standing water around the roots. It is found in both indoor and outdoor plants, although ...

from '' Phytophthora lateralis''. This rot moves up the tree and kills the inner bark, thereby leading to the death of the tree. Furthermore, wildfire risk continues to increase as global climate change leads to hotter and drier conditions.

Historical Usage

Native Americans

The estuary is land of the Coos and the Coquille––specifically the Miluk people––who have lived in the area for approximately 6,000 years. The flora and fauna of the watershed provided significant amounts of food and material for hunting and shelter. Villages generally homed around 100 people. Shortly after European settlers arrived in the 1850s, the Natives were forcibly removed and forbidden to return to their land. In the 1870s, "eligible" Natives were allotted a plot of land on which they could rebuild homes. This program was deeply ingrained within colonization, and therefore promoted assimilation in the Euro-American culture. Today, the Coos peoples are a part of th
Confederated Tribes of the Coos, Lower Umpqua, and Siuslaw Indians
Coos_Bay

Deep-Draft Navigation Project

The estuary has a long history of dredging, deepening, and spoil disposal, dating back to early development in the mid-1800's. In 1976, the Coos Bay was dredged as part of the Deep-Draft Navigation Project, a campaign by the

US Army Corps of Engineers , colors = , anniversaries = 16 June (Organization Day) , battles = , battles_label = Wars , website = , commander1 = ...

to increase channel depth and width for vessel usage. In its natural state, the estuary's entrance was approximately 200 feet wide and 10 feet deep; this project altered the entrance to measure 700 feet wide and 45 feet deep. Total estuary volume has increased 21% while the total estuary areas has decreased by 12%. In contrast, 25 km² of the estuary in South Slough has been managed by the

and left unaltered by development. A harbor and bridge were constructed in the entrance of South Slough, and the entry point of Coos River into the estuary has been redirected to the west, partially separating it from the east-estuary flats. As a result of this, modeling reveals, the estuary has overall become more stratified and accumulates more sediment than it did historically. Further deepening of the navigation channel from 11 to 14 m and widening by about 45 m has already been proposed for the western reach. The navigational channel of Coos Estuary is regularly dredged to this day to allow for commercial shipping.

Present

Currently, the greater Coos County––which encompasses the watershed––is home to over 63,000 people. A 2014 community report ranked the area poorly in climate adaptation, greenhouse gas mitigation, and resource efficiency, along with a few social and community aspects.

Economy

Fisheries and Aquaculture

Coos Bay hosts several oyster

aquaculture Aquaculture (less commonly spelled aquiculture), also known as aquafarming, is the controlled cultivation ("farming") of aquatic organisms such as fish, crustaceans, mollusks, algae and other organisms of value such as aquatic plants (e.g. lot ...

operations. Clausen's Oysters is located in Haynes Inlet at the north end of the estuary. Qualman Oyster Farms is located near the entrance to South Slough. Additionally, clams are harvested recreationally. Charleston acts as a port for many commercial vessels that fish off of Oregon's coast. Similar to other ports in Oregon, these fisheries include

, Pink shrimp, Pacific whiting,

, Albacore tuna, and Pacific halibut. The prominence of these industries promotes good water quality maintenance.

Shipping Port

The

is one of the largest and deepest ports between

San Francisco, California San Francisco (; Spanish for " Saint Francis"), officially the City and County of San Francisco, is the commercial, financial, and cultural center of Northern California. The city proper is the fourth most populous in California and 17t ...

and the

. The majority of cargo is offloaded in the southeast corner of Coos Bay, which is near the head of the inlet, opposite the Coos River entrance. Currently, 2 million tons of cargo move through the port. There are plans to widen the channel from 300 ft to 450 ft and to deepen it from 37 ft to 45 ft, allowing the shipping operations to scale up. Coupled with the Coos Bay Rail Line, which threads through the Oregon Coast Range to Eugene, the port could see increased usage in coming years.

Natural Gas

Jordan Cove, located across the inlet from the airport, was the proposed site of a

liquefied natural gas Liquefied natural gas (LNG) is natural gas (predominantly methane, CH4, with some mixture of ethane, C2H6) that has been cooled down to liquid form for ease and safety of non-pressurized storage or transport. It takes up about 1/600th the vol ...

(LNG) terminal by Jordan Cove Energy Project. The terminal would have exported liquefied natural gas from an underground pipeline that would have met with existing pipelines near Malin. The terminal and pipeline projects were cancelled in 2021. Oregon Governor Kulongoski expressed various environmental concerns.

External links

Coos Watershed Association

Robbins, William. "Coos Bay". The Oregon Encyclopedia.

Oregon Department of State Lands: About South Slough Reserve

* ttps://www.nerra.org/project/south-slough-national-estuarine-research-reserve/ National Estuarine Research Reserve Association: South Slough Reserve, Oregon

References

{{Authority control Bays of Oregon Estuaries of Oregon Bodies of water of Coos County, Oregon Oregon Coast