Valued Resources in Estuaries


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Introduction

The categorized list of valued resources below represent the most valued stakeholder interests outlined in a paper by Merryl Alber (Alber 2002). Stakeholder interests are the benefits an estuarine system provides for humans. They are the values that make estuarine systems worth maintaining and capable of being a sustainable environment. A sustainable environment is one that continues to be productive. Productivity is the recurrent creation of biomass through estuarine interrelationships and processes.

Choosing resources to conserve is necessary because it may define the estuarine study area, the public interest’s and what they are willing to protect, the collection of data, as well as the policies that can be passed based on applicable Acts.

Some estuarine resources are valued more highly than others depending on the estuaries’ system dynamics and stakeholder’s interests. Identifying the estuarine resources that are important to an area is necessary because there are almost always budget constraints placed on management projects. Also, most proposed policy’s approval hinders on the interests of community members and their willingness to make concessions.

Some definitions of valued resources are interchangeable with that of ecosystem services. Ecosystem services are those resources and processes environments provide for anthropogenic use free of charge. The economic value of estuarine U.S. ecosystem services is valued in the trillion.

Source: chesapeakebay.net

Source: chesapeakebay.net

      Intrinsic values

Intrinsic value is the belief that something has value in and of itself. The intrinsic value of some resource is not necessarily measured monetarily. It can be measured by what it represents to humans.

One example would be The Aransas Project (TAP) lawsuit against the state of Texas (Berner et al. 2013). The loss of several whooping cranes migrating through the Texas coast caused uproar in the coastal community. The whooping cranes hold great intrinsic value to the local community and to birdwatchers who travel annually to see the birds in their natural habitat. A lawsuit was brought against the state of Texas, which was found in violation of the Endangered Species Act because the removal of freshwater due to water permits issued by TCEQ reduced freshwater inflows necessary for the whooping crane’s main food source, the blue crab, causing whooping crane mortalities. The decision held TCEQ cannot issue water permits for the San Antonio and Guadalupe Rivers until it creates a Habitat Conservation Plan that will ensure inflows to San Antonio Bay and an Incidental Take Permit for whooping cranes (Berner et al. 2013). The litigation is subject to appeal, and the Federal Appeals Court in New Orleans issued a stay of the ruling by the Lower Court in Corpus Christi (Berner et al. 2013).

Source: www.tpwd.state.tx.us

Source: www.tpwd.state.tx.us

Navigation

Estuaries provide means of navigation along coasts through inter-bay connections. Navigation via estuaries provides greater protection from storms and tidal action because of the sandbars and peninsulas that border the estuaries.

Navigation through often shallow estuaries, such as is the case through the Gulf of Mexico Intracoastal Waterway, requires information of the tidal currents timing, height, speed and direction (NOAA 2013). Today’s vessels are larger than vessels used in the past and increased traffic through estuaries leaves no room for mistakes. Monitoring of the water level, water currents, and weather patterns are critical for safe navigation (NOAA 2013).  Tidal mixing may change based on the amount of freshwater inflows and so a better understanding of the fluctuations in water levels during tidal cycles is necessary for habitat restoration projects to meet necessary flow levels.

Inracoastal Waterway Source: www.travel.thefuntimes.org

Inracoastal Waterway Source: www.travel.thefuntimes.org

Assimilative Capacity 

The assimilative capacity of an estuary is the ability of that estuary to remove contaminants in the water by plants absorption and organisms assimilation into their body tissues (USEPA 2005).  This process can greatly reduce the impacts from waste reaching the ocean.  Decreased quality of freshwater inflows into estuarine areas can cause increased nutrient loading, decreasing the ability of the ecosystem to filter contaminants. Nutrient enrichment can cause eutrophication, causing degraded conditions in estuaries.

Estuarine Vegetation and Oysters Source: dcm2.enr.state.nc.us

Estuarine Vegetation and Oysters Source: dcm2.enr.state.nc.us

Recreational Fisheries and Commercial Fisheries

Every year in the United States, recreational and commercial fisheries generate billions of dollars for the economy (Lellis-Dibble et al. 2008). Much of the fish are caught and/or harvested from estuaries. Commercial estuarine species including fish and shellfish accounted for 68% of the U.S. commercial fishery landings from 2000 through 2004; recreational estuarine species of fish and shellfish accounted for nearly 80% of the fish harvested nationwide from 2000 through 2004 (Lellis-Dibble et al. 2008).  Estuaries play important roles for fisheries by providing nursery habitat and food for fish leading to increased fishery productivity, i.e., fish and shellfish species, which translates to billions of dollars for the coastal economy.

Redfish. Source: www.denalirods.com

Redfish. Source: www.denalirods.com

Wildlife Habitat

The wildlife of a region can be defined as the native fauna, or animals, that are undomesticated and living in the wild. Wildlife is greatly enjoyed by birdwatchers and hunters alike, although for very different reasons. Whether protection of wildlife is of interest because it is beautiful, edible, or intrinsically valuable, wildlife needs certain habitat types in order to survive.

When any endangered or threatened wildlife in the U.S. is listed under the Endangered Species Act, the habitat that animal occupies that is essential to its survival are designated as critical habitat (USFWS 2013c). Estuaries provide critical habitat types for many wildlife species and their prey. Decreased freshwater inflows can adversely affect wildlife habitats.  Much estuarine habitat specific vegetation such as seagrass is adapted to survival on land that is partially or completely inundated at least some of the time. Lack of freshwater inflows and drought conditions reduce estuarine habitat’s vegetative cover that can provide breeding grounds, shelter, and prey causing stressors to the wildlife populations (Montagna et al. 2013b).

Seagrass. Source: www.eoearth.com

Seagrass. Source: www.eoearth.com

In Texas, wildlife includes the protected native wild mammals, birds, reptiles, amphibians, and freshwater organisms. Texas’ dominant habitat types within estuaries include unconsolidated sand or mud, seagrass beds, saltmarshes, oyster reefs, and mangroves. The location and range of estuarine habitat types can be correlated with the average annual precipitation gradient that occurs along the Texas coast. The northeastern Texas coastal area is classified as humid while the southwesterly Texas coastal area is considered subtropical and semiarid. Some examples of important estuarine wildlife species in Texas include whooping cranes, black drum, red drum, shrimp, oysters, crabs, and many others. Critical wildlife habitat is valued because it provides essential components necessary for many wildlife species.

Resources:

Critical habitat for threatened and endangered species can be found using a GIS based tool provided by the US Fish and Wildlife Services Website at:

http://criticalhabitat.fws.gov/crithab/

Aesthetic, recreational value

Kiteboarding. Source: www.groupon.com

Kiteboarding. Source: www.groupon.com

Healthy estuaries are aesthetically pleasing and are good places to enjoy recreational activities. Healthy estuaries have diverse flora and fauna that draw many people to the coast. They are also great places to enjoy a seemingly endless list of recreational activities including fishing, hunting, kayaking, boating, sailing, wakeboarding, skiing, birdwatching, kiteboarding, crabbing, and much more. These values are reasons why many people are interested in estuarine conservation.

Intertidal Wetlands

Intertidal Zone. Source: pangea.stanford.edu

Intertidal Zone. Source: pangea.stanford.edu

Texas’ estuarine intertidal wetlands have decreased by 9.5% from the mid-1950’s to the early 90’s from natural and human induced causes (Moulton et al. 1997). Intertidal wetlands are estuarine ecosystems on top or within the surface layer between low and high tide (Montagna et al. 2013). Tides that have one high and low tide are referred to as diurnal tides (Montagna et al. 2013). Tides that have two repeating cycles of one high and low tide are semidiurnal (Montagna et al. 2013). The rising and falling of the volume of water in the estuary cause tides.

Intertidal wetlands are highly productive estuarine ecosystems. They are important breeding grounds and nurseries for much economically important marine life; an estimated two-third’s of the world’s fish catches spend a portion of their life cycle in the intertidal wetlands (Kleeman and Forrest 2000).

Blue crab. Source: www.missionaransas.org

Blue crab. Source: www.missionaransas.org

One highly valued species in Texas that takes advantage of the intertidal zone is the blue crab. The blue crab uses the intertidal zone for protection during its megalopae life stage where the larvae moves from the ocean bay into the bay and settles in the intertidal zone to the metamorphose stage into a true blue crab where it develops from a juvenile to an adult (NERRS 2013).

 

 

 

Rare and Endangered Species

Brown Pelican. Source: content.usatoday.com

Brown Pelican. Source: content.usatoday.com

Rare and endangered species are those whose population numbers are low and therefore at risk of going extinct (USFWS 2013c). Rare or endangered species are at risk for genetic drift, genetic bottlenecks, and decreased breeding pairs. A population’s numbers may decrease for many reasons. When a species’ population numbers fall dangerous low, they are eligible for addition to the Rare and Endangered Species Act of 1973 list (USFWS 2013c). The U.S. Fish and Wildlife Service and the National Marine Fisheries Service administer the Act (USFWS 2013c). Some of the Federal Trust Species found on the Texas coast are the whooping crane, brown pelican, loggerhead sea turtle, Canada goose, eastern oyster, red drum, white shrimp, and blue crab (USFWS 2013c).

Essential Fish Habitat

Dynamic commercial and recreational fisheries are inappreciably linked to healthy marine habitats (NOAA 2013). Essential fish habitats are the healthy environments fish and other aquatic and semi-aquatic organism’s need to survive, feed, reproduce, and grow to maturity. Estuaries provide essential habitat conditions for oysters and nurseries habitats for fish.

Resources:

Hamline University’s “Celebrating the Estuaries of the Texas Coastal Bend”                                 In an estuarine system the effects of changing freshwater inflow levels can harm the organisms. Hamline University has created mulitmedia projects and published them online to demonstrate the effects of changing freshwater inflow levels on estuarine system organisms and resources. It includes a teachers guide, a Google Earth Estuary Tour, and a interactive game, and feedback links.

The information can be accessed at: http://cgee.hamline.edu/CoastalBendEstuaries/                               Hamline University game: http://cgee.hamline.edu/WTTS-Guadalupe/


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