SEARCH · Search USGS

Results for “Fish Farming Industries”

Search indexed USGS publications on groundwater, aquifers, geologic maps, mineral resources and earthquakes. Explore source records by subject and place.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

30 records · Page 2Linked to original sources

USGS2021

Oregon and Landsat

Oregon’s landscape is as complex and diverse as it is beautiful. Mountain peaks in the Cascade Range soar higher than 10,000 feet. Crater Lake sinks to a depth of 1,943 feet, making it the deepest lake in the United States. Oregon’s lands feature forests, farm fields, grasslands, ocean coastline, rivers, a semidesert, and mountain ranges that stretch across the State. A wide range of birds, animals, and fish—including 16 federally endangered species—share this space with more than 4 million people. With Oregon’s economy tied to these natural resources, industries like agriculture, timber, and fishing interlace with the well-being of wildlife and residents. Landsat data and imagery are one of many U.S. Geological Survey tools used by State resource managers and scientists to help achieve a natural balance and provide information about forests, habitats, and much more to Oregon decision makers. This will become even more important as research indicates climate change will make extreme weather more likely, leading to the likely increase in droughts, infestation, wildfires, and other natural hazards.

Oregon↗

USGS2022

New Jersey and Landsat

New Jersey ranks among the smallest of States but packs a lot within its borders. Of course, that includes the more than 9 million people who make it the most densely populated State, but it also includes diverse landscapes. Ranging from Atlantic Ocean barrier islands and beaches to the Appalachian Mountains, and Pine Barrens forests to swampland, the “Garden State” retains remnants of an agricultural past with produce, horse, and dairy farms and plant nurseries. The third State to join the Union has had a strong geographic presence in U.S. history. More than 200 American Revolution battles and skirmishes were fought in New Jersey—more than in any other State. Manufacturing, tourism, and fishing have each had a significant effect on New Jersey’s industrial history. Today, many residents commute from this strategic location to work in New York City, just across the Hudson River to the northeast, or in Philadelphia, just across the Delaware River to the west. A dense population and environmental changes can increase risks for residents and the natural resources around them. Landsat helps officials monitor and plan for resilient cities and landscapes.

New Jersey↗

USGS1990

Hydrologic characteristics of the Great Salt Lake, Utah: 1847-1986

The Great Salt Lake in Utah is a large body of water bordered on the west by barren desert and on the east by a major metropolitan area. It is the fourth largest terminal lake in the world, covering about 2,300 square miles in 1986. Since its historic low elevation of 4,191.35 feet in 1963, the lake rose to a new historic high elevation of 4,211.85 feet in 1986. Most of this increase (12.2 feet) occurred after 1982. The rise has caused $285 million of damage to lakeside industries, transportation, farming, and wildlife. Accompanying the rapid rise in lake level has been a decrease in salinity-from 28 percent in 1963 to about 6 percent in 1986. This has resulted in changes in the biota of the lake from obligate halophiles to opportunistic forms, such as blue-green algae and, most recently, a brackish-water fish.

Utah↗

USGS2015

Effects of geoduck (Panopea generosa) aquaculture on resident and transient macrofauna communities of Puget Sound, Washington, USA

In Washington state, commercial culture of geoducks ( Panopea generosa ) involves large-scale out-planting of juveniles to intertidal habitats, and installation of PVC tubes and netting to exclude predators and increase early survival. Structures associated with this nascent aquaculture method are examined to determine whether they affect patterns of use by resident and transient macrofauna. Results are summarized from regular surveys of aquaculture operations and reference beaches in 2009 to 2011 at three sites during three phases of culture: (1) pregear (-geoducks, -structure), (2) gear present (+geoducks, +structures), and (3) postgear (+geoducks, -structures). Resident macroinvertebrates (infauna and epifauna) were sampled monthly (in most cases) using coring methods at low tide during all three phases. Differences in community composition between culture plots and reference areas were examined with permutational analysis of variance and homogeneity of multivariate dispersion tests. Scuba and shoreline transect surveys were used to examine habitat use by transient fish and macroinvertebrates. Analysis of similarity and complementary nonmetric multidimensional scaling were used to compare differences between species functional groups and habitat type during different aquaculture phases. Results suggest that resident and transient macrofauna respond differently to structures associated with geoduck aquaculture. No consistent differences in the community of resident macrofauna were observed at culture plots or reference areas at the three sites during any year. Conversely, total abundance of transient fish and macroinvertebrates were more than two times greater at culture plots than reference areas when aquaculture structures were in place. Community composition differed (analysis of similarity) between culture and reference plots during the gear-present phase, but did not persist to the next farming stage (postgear). Habitat complexity associated with shellfish aquaculture may attract some structure-associated transient species observed infrequently on reference beaches, and may displace other species that typically occur in areas lacking epibenthic structure. This study provides a first look at the effects of multiple phases of geoduck farming on macrofauna, and has important implications for the management of a rapidly expanding sector of the aquaculture industry.

Washington↗

USGS2002

Organochlorine chemical residues in fish from the Mississippi River basin, 1995

Fish were collected in late 1995 from 34 National Contaminant Biomonitoring Program (NCBP) stations and 13 National Water Quality Assessment Program (NAWQA) stations in the Mississippi River basin (MRB) and in late 1996 from a reference site in West Virginia. Four composite samples, each comprising (nominally) 10 adult common carp (Cyprinus carpio) or black bass (Micropterus spp.) of the same sex, were collected from each site and analyzed for organochlorine chemical residues by gas chromatography with electron capture detection. At the NCBP stations, which are located on relatively large rivers, concentrations of organochlorine chemical residues were generally lower than when last sampled in the mid-1980s. Residues derived from DDT (primarily p,p???-DDE) were detected at all sites (including the reference site); however, only traces (??? 0.02 ??g/g) of the parent insecticide (p,p???-DDT) were present, which indicates continued weathering of residual DDT from past use. Nevertheless, concentrations of DDT (as p,p???-DDE) in fish from the cotton-farming regions of the lower MRB were great enough to constitute a hazard to fish-eating wildlife and were especially high at the NAWQA sites on the lower-order rivers and streams of the Mississippi embayment. Mirex was detected at only two sites, both in Louisiana, and toxaphene was found exclusively in the lower MRB. Most cyclodiene pesticides (dieldrin, chlordane, and heptachlor epoxide) were more widespread in their distributions, but concentrations were lower than in the 1980s except at a site on the Mississippi River near Memphis, TN. Concentrations were also somewhat elevated at sites in the Corn Belt. Endrin was detected exclusively at the Memphis site. PCB concentrations generally declined, and residues were detected (??? 0.05 ??g/g) at only 35% of the stations, mostly in the more industrialized parts of the MRB.

Archives of Environmental Contamination and Toxico↗

USGS2001

Tampa Bay Integrated Science Pilot Study: wetland characterization

Coastal wetlands in Tampa Bay consist of mangrove forest and tidal salt marsh. Wetlands buffer storm surges, provide fish and wildlife habitat, and enhance water quality through the removal of water-borne nutrients and contaminants. Substantial areas of both mangrove and salt marsh have been lost to agricultural, residential and industrial development in this urban estuary. Wetlands restoration has been initiated in Tampa Bay. Baseline studies on the current condition of wetlands and historical and prehistorical information is needed for successful restoration planning and evaluation. A major objective of this component of the Tampa Bay pilot program was to characterize wetlands in Tampa Bay beginning with areas that differ in their degree of human-induced disturbance ( Fig. 1 ). The Alafia River area is urbanized, industrialized and dredged, whereas the Terra Ceia area has a history of agricultural use with associated soil berms and mosquito ditches, but has not been farmed for at least 20 years ( Fig. 2 ).

Open-File Report↗

USGS2007

Sperm cryopreservation in fish and shellfish

Initial success in sperm cryopreservation came at about the same time for aquatic species and livestock. However, in the 50-plus years since then cryopreserved sperm of livestock has grown into a billion-dollar global industry, while despite work in some 200 species with well over 200 published reports, cryopreservation of aquatic species sperm remains essentially a research activity with little commercial application. Most research has focused on large-bodied culture and sport fishes, such as salmonids, carps, and catfishes, and mollusks such as commercially important oyster and abalone species. However, only a handful of studies have addressed sperm cryopreservation in small fishes, such as zebrafish, and in endangered species. Overall, this work has yielded techniques that are being applied with varying levels of success around the world. Barriers to expanded application include a diverse and widely distributed literature base, technical problems, small sperm volumes, variable results, a general lack of access to the technology, and most importantly, the lack of standardization in practices and reporting. The benefits of cryopreservation include at least five levels of improvements for existing industries and for creation of new industries. First, cryopreservation can be used to improve existing hatchery operations by providing sperm on demand and simplifying the timing of induced spawning. Second, frozen sperm can enhance efficient use of facilities and create new opportunities in the hatchery by eliminating the need to maintain live males, potentially freeing resources for use with females and larvae. Third, valuable genetic lineages such as endangered species, research models, or improved farmed strains can be protected by storage of frozen sperm. Fourth, cryopreservation opens the door for rapid genetic improvement. Frozen sperm can be used in breeding programs to create improved lines and shape the genetic resources available for aquaculture. Finally, cryopreserved sperm of aquatic species will at some point become an entirely new industry itself. A successful industry will require integrated practices for sample collection, refrigerated storage, freezing, thawing, rules for use and disposal, transfer agreements, and database development. Indeed the development of this new industry is currently constrained by factors including the technical requirements for scaling-up to commercial operations during the transition from research, and the absence of uniform quality control practices, industry standards, marketing and price structures, and appropriate biosecurity safeguards.

Society for Reproduction and Fertility Supplement↗

USGS1965

Hydrology of the Little Plover River basin, Portage County, Wisconsin, and the effects of water resource development

The Little Plover River basin is in the sand-plain area of central Wisconsin. The basin and the surrounding sand-plain area provide a good fish and wildlife habitat and is a popular locale for sport fishing. Good yields may be obtained in the area from irrigated crops, and the irrigated acreage has been increasing rapidly in recent years. Sportsmen and conservationists are concerned about the effects of increased development of the water resources on the streams as trout habitat. In the past, many political and legal conflicts among water users have arisen from erroneous opinions as to the behavior of water. Many of these conflicts would be diminished or eliminated if the participants were cognizant of fundamental hydrologic principles. This study was made to demonstrate the extent and nature of the interrelation of ground water and surface water and the fundamental hydrologic principles governing water movement. The study was also made to determine the hydrologic changes that might occur following development, to provide information that might be used as a basis for planning water development, and for drafting legislation that recognizes the relation between ground water and surface water. Water has been developed in the Little Plover River basin for industry, for domestic and stock supplies, and for irrigation. Irrigated acreage is increasing in the area, and the use of water for irrigation may alter the hydrology of the basin somewhat. About 4,000-4,500 acres of land within the basin, or 50-60 percent of the basin area, is suitable for irrigated farming, but probably no more than 2,500 acres will be under irrigation in any one year, unless present crop-rotation practices are changed. Most of the Little Plover River basin is underlain by from 40 to 100 feet of glacial outwash consisting of highly permeable sand and gravel. The glacial outwash is the main aquifer in the area and is capable of yielding large quantities of water to wells. An aquifer test in the area indicated that the coefficient of transmissibility of the glacial outwash is about 140,000 gallons per day per foot. The specific yield of the outwash is about 20 percent, as determined from water-level and streamfiow data. Morainal deposits occur locally with the glacial outwash. These deposits transmit water readily and do not form barriers to ground water in the outwash. Relatively impermeable crystalline rocks underlie the glacial deposits, and a sandstone ridge of low permeability impedes the movement of ground water from the basin by underflow. The glacial outwash and morainal deposits are recharged by infiltration of 9-10 inches of the 31 inches of precipitation that falls on the area in an average year. If it is not withdrawn by wells for consumptive use or by phreatophytes, water that infiltrates the sand and gravel discharges later into the Little Plover River. This ground-water discharge constitutes 90-95 percent of the total flow of the Little Plover River. Annual evapotranspiration varies considerably, but generally ranges from 2 to 8 inches less than the potential evapotranspiration of 24 inches. Consumptive use of irrigation water averages about 4 inches per year. Most of the water pumped from wells otherwise would be discharged to the stream, and consumptive use of irrigation water will deplete streamflow by the amount of evapotranspiration. Pumping wells have little effect on the water level in the highly permeable sand and gravel. Significant interference between wells would occur only if large capacity wells were within a few tens of feet of each other. Ground water and surface water are closely interrelated in the sand-plain area and ground-water withdrawals near the Little Plover River may cause a measurable streamflow depletion. In a test, a well that was pumping about 1,120 gpm (gallons per minute) and that was 300 feet from the stream derived about 30 percent of its flow from the stream after 3 days of pumping. For this study, the effects of increased ground-water development were evaluated from a hypothetical development schedule, for which it was assumed that 500 acres were irrigated the first year and that an additional 50 acres were irrigated in each succeeding year for 10 years. It also was assumed that the average annual consumptive-use requirement for irrigation water would be one- third of an acre-foot per acre. Calculations indicate that the maximum monthly rate of depletion due to the consumptive use of 4 inches of ground water per year on 500 acres would be about 0.4 cfs (cubic feet per second) the first year and 0.5 cfs after 10 years of pumping. Other computations indicate that the maximum monthly rate of depletion due to irrigating 500 acres the first year and 50 additional acres each year for 10 years would be about 0.8 cfs. Maximum depletion would occur during the summer months, concurrent with the irrigation withdrawals. Because of the close interrelation between ground and surface water, surface- water withdrawals will cause an increased inflow of ground water to the stream and a decline in ground-water levels near the stream. These effects were demonstrated by pumping from the stream. After 29 hours of pumping, a depletion of 1,120 gpm at a site 7,000 feet downstream was about 200 gpm less than the diversion at the pump. Most of the 200 gpm was supplied from the stream-banks, and ground-water levels near the stream declined as much as 0.3 foot. Computations indicated that ground-water inflow, following a streamflow diver- sion that lowered the stage 0.15 foot, would be 0.14 cfs after 5 days and 0.06 cfs after 30 days. The demonstration of the quantitative relation between ground water and surface water, as given by this study, should provide a sound basis for planning water development to minimize conflicts of interest. The demonstrations also should provide a basis for drafting legislation that recognizes the interrelation of ground water and surface water. Because the geology and the hydrology are relatively uniform throughout the sand plains, many of the methods and hydrologic values determined for this detailed study of the Little Plover River basin may be applied to other basins in the sand-plain area.

Wisconsin↗

USGS2003

Boll weevil eradication: a model for sea lamprey control?

Invasions of boll weevil ( Anthonomus grandis ) into the United States and sea lamprey ( Petromyzon marinus ) into the Great Lakes were similar in many ways. Important species (American cotton, Gossypium hirsutum , and lake trout, Salvelinus namaycush ) and the industries they supported were negatively affected. Initial control efforts were unsuccessful until pesticides and application technologies were developed. For boll weevils, controls relying on pesticides evolved into an integrated program that included recommended farming practices and poisoned baits. However, the discovery of a boll weevil sex pheromone in 1964 allowed adoption of an ongoing program of eradication. Despite opposition over concept and cost, insecticides, pheromone traps, poisoned baits, and approved farming practices were used to eradicate boll weevils from Virginia, North Carolina, South Carolina, Georgia, Florida, and Alabama by 1999. Using the working back approach along the path of the original invasion, eradication was nearly completed by 2002 in Mississippi and eradication programs were underway in Arkansas, Tennessee, Oklahoma, Louisiana, and parts of Texas. Insecticide use for cotton production decreased 50 to 90%, and cotton yields and farm income increased an average of 78 kg/ha and $190 U.S./ha in areas where boll weevils were eradicated. For sea lampreys, integrated management uses lampricides, barriers to migration, trapping, and release of sterilized males. Although sea lamprey eradication is not currently feasible, recent research on larval and sex pheromones might provide the tools to make it possible. A successful eradication program for sea lampreys starting in Lake Superior and expanding to the lower Great Lakes would ultimately provide huge ecological and economic benefits by eliminating lampricide applications, removing barriers that block teleost fishes, and facilitating the recovery of lake trout. Should the opportunity arise, the concept of sea lamprey eradication should not be rejected out of hand. The successful boll weevil eradication program shows that sea lamprey eradication might be achievable.

Journal of Great Lakes Research↗

USGS2019

Quantifying risk of whale–vessel collisions across space, time, and management policies

Transportation industries can negatively impact wildlife populations, including through increased risk of mortality. To mitigate this risk successfully, managers and conservationists must estimate risk across space, time, and alternative management policies. Evaluating this risk at fine spatial and temporal scales can be challenging, especially in systems where wildlife–vehicle collisions are rare or imperfectly detected. The sizes and behaviors of wildlife and vehicles influence collision risk, as well as how much they co‐occur in space and time. We applied a modeling framework based on encounter theory to quantify the risk of lethal collisions between endangered North Atlantic right whales and vessels. Using Automatic Identification System vessel traffic data and spatially explicit estimates of right whale abundance that account for imperfect detection, we modeled risk at fine spatiotemporal scales before and after implementation of a vessel speed rule in the southeastern United States. The expected seasonal mortality rates of right whales decreased by 22% on average after the speed rule was implemented, indicating that the rule is effective at reducing lethal collisions. The rule's effect on risk was greatest where right whales were abundant and vessel traffic was heavy, and its effect varied considerably across time and space. Our framework is spatiotemporally flexible, process‐oriented, computationally efficient and accounts for uncertainty, making it an ideal approach for evaluating many wildlife management policies, including those regarding collisions between wildlife and vehicles and cases in which wildlife may encounter other dangerous features such as wind farms, seismic surveys, or fishing gear.

Georgia, Florida↗

USGS1995

The ecology of cormorants: some research needs and recommendations

Concerns about Double-crested Cormorants (Phalacrocorax auritus) have arisen because of their rapid population increase across North America and their economic impact on several aquaculture and commercial fish industries. In spite of the concern for cormorants, little published research is available that addresses either basic population biology questions or management issues. Based on a literature review, I recommend that research be conducted in four areas. First, a large-scale banding and marking program should be initiated so that population models can be used to estimate age- and sex-specific survival and fecundity (as has been done for the Shag [P. aristotelis] in Europe). By marking individual birds, survival and movement rates can be estimated between nesting colonies, which will provide information about potential source versus sink colonies. Second, studies of movements during migration and winter are required. Presently, no data are available on habitat use during migration or on the length-of-stay by individual birds. This has important implications to how cormorants interact with other fish and wildlife species over a broad range. Studies of movements during winter with radio-marked birds should indicate whether the 'problem birds' at aquaculture sites are merely a few specialists. Third, limiting factors, such as contaminants and disease, should receive further investigation, especially in light of recent concerns over the outbreak of Newcastle disease. The relationship between contaminant levels and developmental abnormalities in young cormorants in certain areas of the Great Lakes in Canada and the United States remains equivocal. Fourth, further studies are needed to document the economic impacts of cormorants on Channel Catfish (Ictalurus punctatus) and other cultured fishes and to determine ways to reduce predation by fish-eating birds. Mesocosm experiments should be conducted to evaluate how different fish extraction rates affect final productivity of fish. Controlled experiments with different exclusion and scaring devices are needed. With radio-marked birds, it should be determined what the behavioral responses are to the different scaring devises. Also, providing alternative wetland feeding sites in regions of fish farm depredation might alleviate some of the pressure on farmers. Studies with radio-marked birds could evaluate effects of manipulation of 'natural' wetlands on use by birds during the winter period. Finally, any research directed at the Double-crested Cormorant should also evaluate its interactions with other fisheating waterbirds.

Book chapter↗

USGS1996

Nutrient sources and analysis of nutrient water-quality data, Apalachicola-Chattahoochee-Flint River basin, Georgia, Alabama, and Florida, 1972-90

In 1991, the U.S. Geological Survey began full-scale implementation of the National Water-Quality Assessment (NAWQA) program. One of the initial tasks of the NAWQA program is to compile and evaluate existing data from individual study units. Available nutrient data from 1972 through 1990 water years were used to estimate nutrient sources to the Apalachicola–Chattahoochee–Flint (ACF) River basin and describe the presence, distribution, and transport of nutrients in surface and ground waters. In 1990, about 2,500 tons of nitrogen and 1,100 tons of phosphorus were discharged as point-source loads by 127 municipal wastewater-treatment facilities (WWTF). Nonpoint-source inputs, an unknown percentage of which entered the hydrologic system, included about 120,000 tons of nitrogen and 28,000 tons of phosphorus from animal manure; 82,000 tons of nitrogen and 20,000 tons of phosphorus applied as fertilizer; and 24,000 tons of nitrogen from atmospheric deposition. Estimates of nutrient input to the ACF River basin were not made for natural sources and for the following anthropogenic sources: industrial-wastewater effluent; storm drains; sanitary and combined sewer outflows; and runoff from agricultural, urban, and suburban areas. Nutrient outflow from the Apalachicola River into Apalachicola Bay, Fla., was about 13 percent of estimated nitrogen sources and about 3 percent of estimated total-phosphorus sources in the ACF River basin. For 1972–90, nutrient concentrations in surface water were high enough to warrant concerns about accelerated eutrophication based on total-phosphorus concentrations and to warrant concerns intermittently about toxicity to fish based on dissolved-ammonia concentrations downstream of wastewater-treatment outfalls from Metropolitan Atlanta and LaGrange, Ga. Many improvements to the water quality of the Chattahoochee and Flint Rivers in the 1980’s and early 1990’s can be directly attributed to improvements in WWTF, legislation directed at decreasing point-source loads of phosphorus, and changes in locations of wastewater-treatment outfalls. However, limited data indicate that nonpoint-source inputs increased upstream of Atlanta and in the Chipola River watershed. Significant increases in nutrient concentrations, loads, and yields occurred from upstream to downstream of the metropolitan areas of Atlanta, Ga.; Columbus, Ga., and Phenix City, Ala.; and Albany, Ga. The highest mean-annual yields estimated in the ACF River basin for total nitrogen (2.9 tons per square mile (tons/mi 2 )), total-inorganic nitrogen (2.0 tons/mi 2 ), dissolved ammonia (1.1 tons/mi 2 ), and total phosphorus (0.75 tons/mi 2 ) were downstream of Atlanta. Most significant trends in nutrient-concentration data from 1980–90 in the Chattahoochee River and the Middle and Lower Flint River basins were increasing, except dissolved ammonia which decreased at several sampling sites in reaches downstream of Atlanta, Columbus and Phenix City, and Albany. At sampling sites on the Chattahoochee and Flint Rivers downstream of Atlanta and Albany, decreasing trends in dissolved-ammonia concentration and increasing trends in dissolved-nitrate concentration were the result of improved wastewater treatment at WWTF. Dissolved-ammonia concentrations decreased and dissolved-nitrate concentrations increased along river reaches downstream of wastewater-treatment facility outfalls for Atlanta and Albany because of nitrification of ammonia to nitrate. Increasing trends in total-phosphorus concentrations are an accurate representation of data for the period 1980–90. However, legislated restrictions on the use of phosphate detergents and improvements to WWTF in the late 1980’s and early 1990’s, resulted in substantial reductions of phosphorus concentrations in wastewater effluent and in rivers at many locations in the 1990’s. Reservoirs affect nutrient transport because of uptake by phytoplankton and aquatic plants, denitrification,and accumulation of phosphorus associated with sediment in reservoirs. Yields of total-inorganic nitrogen, dissolved ammonia, dissolved nitrate, and total phosphorus decreased between sampling sites upstream and downstream of four reservoirs on the Chattahoochee River. The only exception was the yield of dissolved ammonia increased slightly from upstream to downstream of Lake Sidney Lanier. Much of the nutrient load in the Chattahoochee River downstream of Atlanta is utilized by algae or settles out primarily in West Point Lake, and to a lesser extent, in Lake Harding and Walter F. George Reservoir. In general, the Flint River arm of Lake Seminole had significantly higher concentrations of nutrients than the Chattahoochee River arm of Lake Seminole, which may be the result of the large percentage of the Middle and Lower Chattahoochee River in backwater from reservoirs, the absence of reservoirs on the Flint River downstream of Albany until Lake Seminole, and nonpoint-source inputs of nutrients from intensively farmed areas in the Lower Flint River basin. Decreases in dissolved-ammonia, dissolved-nitrate, and total-phosphorus concentrations in reservoirs and backwater along the Chattahoochee River from West Point Lake to Lake Seminole during summer months are related to the seasonality of phytoplankton production. The Chipola River had the highest yields of dissolved nitrate (1.2 tons/mi 2 ) estimated in the ACF River basin. Estimated loads of dissolved nitrate increased fairly steadily from 500 to 1,500 tons per year from 1972–90. These factors strongly suggest an agricultural nonpoint source of elevated dissolved-nitrate concentrations from increased irrigated agriculture and fertilizer applications in the Chipola River watershed. Analyses of nutrients in ground water within the ACF River basin for 1972–90 water years were restricted because of limited available data. The distribution of nitrate concentrations in the ACF River basin for 1972–90 water years included 10 percent of wells and 6 percent of springs with concentrations that probably have elevated nitrate concentrations (3.1 to 10 milligrams per liter (mg/L)), and 1 percent of wells with median nitrate concentrations exceeding the maximum contaminant level of 10 mg/L. Dissolved-nitrate concentrations were significantly lower in the Providence aquifer than in the Floridan aquifer system and the crystalline-rock aquifers. Dissolved-nitrate concentrations in wells used for public supply were significantly lower than in wells used for domestic use or unused wells.

Alabama, Florida, Georgia↗