USGS Newsroom

Sea Turtles Benefiting From Protected Areas

OC_Web@usgs.gov (Office of Communications and Publishing) — Mon, 29 Apr 2013 11:00:00 EDT

Study Offers First Look at Green Sea Turtle Habitat Use in the Dry Tortugas

Additional Contact: Kristen Hart, Mobile Phone: 954-650-0336

DRY TORTUGAS, Fla. – Nesting green sea turtles are benefiting from marine protected areas by using habitats found within their boundaries, according to a U.S. Geological Survey study that is the first to track the federally protected turtles in Dry Tortugas National Park.

Green turtles are listed as endangered in Florida and threatened throughout the rest of their range, and the habits of green sea turtles after their forays to nest on beaches in the Southeast U.S. have long remained a mystery. Until now, it was not clear whether the turtles made use of existing protected areas, and few details were available as to whether they were suited for supporting the green sea turtle’s survival.

U.S. Geological Survey researchers confirmed the turtles' use of the protected areas by tracking nesting turtles with satellite tags and analyzing their movement patterns after they left beaches.

"Our goal was to better understand what types of habitats they used at sea and whether they were in fact putting these designated areas to use. This study not only shows managers that these designated protected areas are already being used by turtles, but provides insight into the types of habitats they use most," said the study’s lead author, Kristen Hart, who works as a research ecologist for the U.S. Geological Survey.

Hart's team made the discovery by fitting green sea turtle mothers with satellite tags after they came onto beaches within Dry Tortugas National Park to nest. After tracking their movements and analyzing their time at sea, the team located the areas turtles used between their nesting events and determined where turtles traveled after the nesting season was over.

They found green sea turtles spending much of their time in protected sites within both Dry Tortugas National Park and the surrounding areas of the Florida Keys Marine National Sanctuary.

"We were thrilled to find that these turtles used some areas already under 'protected' status. The ultimate goal is to help managers understand where these endangered turtles are spending their time both during the breeding period and then when they are at feeding areas. Given that worldwide declines in seagrasses – one of the most important habitats they rely on for food – has already been documented, this type of data is critical for managers," said Hart.

The team learned about the turtle's habitat needs during the nesting season by using ATRIS, a georeferenced, underwater camera system developed by the USGS to collect over 195,000 seafloor images. Researchers surveyed the areas frequented by turtles within Dry Tortugas National Park by photographing the seafloor in a series of parallel lines totaling 70 kilometers (over 43 miles). Using a habitat map derived from those images, they found that the turtles most commonly used shallow seagrass beds and degraded coral reefs that have been overgrown by a mixed assemblage of other organisms, such as sea fans, sponges, and fire coral.

"Our synergistic approach of combining satellite telemetry data with an extensive habitat map proved to be an effective way to find out exactly what habitats these nesting turtles were using in the Park," said Dave Zawada, a USGS research oceanographer and co-author on the study.

The Dry Tortugas' population made shorter migrations than that typically seen among other green turtle populations around the world; this was only the second published study showing green turtles taking up residence at feeding grounds located quite near their breeding grounds.

"We hope to keep pushing the frontier of what is known about in-water sea turtle habitat use, as this type of scientific information is vital for understanding whether conservation measures are effective," said Hart.

The study, "Habitat use of breeding green turtles Chelonia mydas tagged in Dry Tortugas National Park: Making use of local and regional MPAs," was published this week in the journal Biological Conservation.

About Green Sea Turtles

Although their young feed on jellyfish and other invertebrates, adult green sea turtles feed on seagrasses and algae, making them the only herbivorous (vegetarian) species of sea turtle. In fact, their name comes from their greenish colored fat, which is thought to be caused by their diet.

Green sea turtles are found around the world in three main types of habitat: nesting beaches, open ocean, and shallow water such as lagoons and shoals where they feed on marine grasses and algae found on the seafloor (‘benthic’ habitat). Within the U.S., green sea turtles are found from North Carolina to Florida, Hawaii, and the Virgin Islands and Puerto Rico. Their breeding populations in Florida are listed as endangered, but all other populations are listed as threatened.

The nesting season for green turtles lasts throughout the summer, but is most concentrated in June and July. During nesting season, females nest at roughly two-week intervals, producing an average of five nests or "clutches." Each clutch contains an average of 135 eggs, which will hatch after incubating for about 2 months.

Lidar Confirms Sandy's Dramatic Coastal Change Impacts and Future Coastal Vulnerability

OC_Web@usgs.gov (Office of Communications and Publishing) — Mon, 26 Nov 2012 10:31:20 EDT

ST. PETERSBURG, Fla. –The extent of Hurricane Sandy's wrath -- and the future coastal vulnerability of the region -- is clear in a new U.S. Geological Survey analysis of recently collected lidar coastal data. The research documented particularly dramatic impacts within the Fire Island National Seashore on Long Island, NY.

Lidar, or light detection and ranging, uses lasers to measure elevations in a specific distance/area. Researchers used the lidar data, collected during an airborne survey, to construct a high-resolution three-dimensional map of before- and after-storm conditions.

This information can help scientists and decision-makers identify the areas along the shore that have been made more vulnerable to future coastal hazards in the storm’s wake.

"Coastal dunes are our last line of natural defense from the onslaught of storms and rising seas," said USGS Director Marcia McNutt. "They are dynamic features that retreat from the battering of major storms like Sandy and rebuild in the aftermath; their natural cycle is inconsistent with immobile development."

USGS research oceanographer Hilary Stockdon said that the lidar data show that at Ocean Bay Park, for example, storm surge and waves associated with Sandy demolished protective dunes – and the structures built on top of them.

"In the pre-storm elevation image of Ocean Beach, you can see houses that are sitting right on the sand dune," Stockdon said. "But in the post-storm elevation image, the high dune elevation is gone. The dune and the houses on it were completely washed away."

The pre- and post-storm ground conditions at Fire Island were similarly dramatic, USGS coastal geologist Cheryl Hapke said, noting that the USGS worked closely with the National Park Service to gather field data on the island.

"We found that there was widespread dune erosion and overwash," Hapke said. "On average, where the dunes were not completely overwashed, they eroded back 70 feet -- the equivalent of 30 years of change. Our research also showed that dunes lost as much as 15 feet of elevation."

The lidar analysis, said Stockdon and Hapke, combined with ground survey data, and pre- and post-storm oblique aerial photography, tell a dramatic story of Sandy’s catastrophic effect on the shoreline – and future coastal vulnerability – in this region. It will also help to demonstrate the accuracy of coastal change predictions calculated before the storm in this area.

"This work can help coastal communities understand where they are most vulnerable to future storms," Stockdon said "and help decision makers at all levels create policies that protect their economic, environmental, and ecological health in the coastal areas most susceptible to extreme storm impacts."

Photos Reveal Severity of Hurricane Sandy's Coastal Impacts

OC_Web@usgs.gov (Office of Communications and Publishing) — Fri, 9 Nov 2012 15:20:00 EDT

ST. PETERSBURG, Fla. – The USGS has released a series of aerial photographs showing before-and-after images of Hurricane Sandy’s impacts on the Atlantic Coast.

The photos, part of a USGS assessment of coastal change from as far south as the Outer Banks of North Carolina to as far north as Massachusetts, show that the storm caused dramatic changes to portions of shoreline extending hundreds of miles. Pre- and post-storm images of the New Jersey and New York shoreline in particular tell a story of a coastal landscape that was considerably altered by the historic storm.

"Sandy taught us yet again that not all Cat-1 hurricanes are created equal: the superstorm's enormous fetch over the Atlantic produced storm surge and wave erosion of historic proportions," said USGS Director Marcia McNutt. "We have seized this opportunity to gather unique data on a major coastline-altering event."

As major storms approach, the USGS conducts pre-storm and post-storm flights to gather aerial images along the length of the coastline expected to experience impacts from the storm’s landfall. Identifying sites of such impacts helps scientists understand which areas are likely to undergo the most severe impacts from future storms, and improves future coastal impact forecasting.

Photo pairs from North Carolina to Massachusetts will be made available online as the coastal change assessment continues.

"This storm's impact on sandy beaches included significant beach and dune erosion and minor disruption of infrastructure in the south," said USGS oceanographer Nathaniel Plant, "to extreme and often catastrophic erosion, overwash and sediment deposition, and inundation on northern beaches like Mantoloking, New Jersey."

Overwash occurs when storm surge and waves exceed the elevation of protective sand dunes, thereby transporting sand inland. In addition to threatening infrastructure like roadways, it can bury portions of buildings and cause extensive property damage. Since beaches and dunes serve as a first line of defense against extreme storms, this could further compromise the safety of coastal populations.

Data collected from these surveys are also used to improve predictive models of potential impacts from future severe storms. Before a storm makes landfall, USGS makes these predictions to help coastal communities identify areas particularly vulnerable to severe coastal change, such as beach and dune erosion, overwash, and inundation.

For instance, in the days before Sandy approached the eastern seaboard, the USGS ran models forecasting that 91 percent of the Delmarva coastline would experience beach and dune erosion, while 98 percent and 93 percent of beaches and dunes in New Jersey and New York, respectively, were likely to erode. Preliminary analysis suggests that Hurricane Sandy rapidly displaced massive quantities of sand in a capacity that visibly changed the landscape.

The USGS worked closely with the National Park Service to gather field data on pre- and post- storm conditions at Fire Island National Seashore on Long Island. The field team went to Fire Island in advance of the storm to capture the morphology of the beach and dunes. The team re-surveyed the beach to capture its state immediately after the storm, and they found drastic changes.

"We found that there was widespread dune erosion and overwash," said St. Petersburg-based USGS coastal geologist Cheryl Hapke. "On average the dunes eroded back 70 feet - the equivalent of 30-years of change, which had previously been measured. Our data also showed that dunes lost as much as 10 feet of elevation."

This rapid response data was used to help the National Park Service assess the areas of the coast that were most vulnerable to a nor'easter that impacted the coast a week after Sandy.

The USGS is also processing pre- and post-landfall airborne lidar data to gather information on the extent of coastal change caused by Sandy. Lidar, or light detection and ranging, is an aircraft-based remote sensing method that uses laser pulses to collect highly detailed ground elevation data.

Isolation of Puerto Rico's Manatees Affects Survival Odds

OC_Web@usgs.gov (Office of Communications and Publishing) — Tue, 23 Oct 2012 9:00:00 EDT

GAINESVILLE, Fla. -- New evidence shows there is no cross-breeding between endangered manatees in Puerto Rico and those in Florida, resulting in less genetic diversity in Puerto Rico's small manatee population and impacting its odds of survival.

The findings, which come from a study of West Indian manatees by the U.S. Geological Survey and Puerto Rico Manatee Conservation Center, could help resource managers make decisions about how to conserve the endangered marine mammal.

"Wildlife management has been one of the fields to benefit greatly from the ability to determine relatedness of individuals from DNA analysis, allowing management decisions to be based on concrete scientific evidence for genetic diversity and prospects for it to increase," said USGS Director Marcia McNutt. "These results for Puerto Rico's manatees are a wake-up call."

One key management concern is the ability of Puerto Rico’s manatees to absorb and rebound from population declines. Current estimates suggest as few as 250 individual manatees may currently live in Puerto Rico. Furthermore, the population’s genetic diversity is low, a fact which decreases a wildlife population’s capacity to adapt to changing conditions and rebound after critical events that can cause deaths, such as hurricanes, boat strikes, or disease.

This latest finding – that Puerto Rico’s manatees are genetically isolated – shows the population’s vulnerability to future ups and downs is not being offset by migration from Florida manatees, as was once hoped.

"Puerto Rico’s Antillean manatees have low overall numbers and low genetic diversity, both of which present risks for the population’s long-term survival," said Margaret Hunter, Ph.D., a USGS geneticist and lead author of the study. "The lack of gene flow is another risk factor. We detected no signs that the Puerto Rico population is being supplemented by Florida manatees, through migration or breeding. This means that Puerto Rico’s population must absorb shocks – such as environmental change or disease – on their own. It’s a trifecta of genetic vulnerability."

In their most recent 5-year review, released in 2007, the U.S. Fish and Wildlife Service recommended that West Indian manatees be downlisted from endangered to threatened, although no decision was made at that time.

As of the last status review, it was difficult to determine whether the two populations were mixing. Puerto Rico's manatees were already considered a different subspecies – the 'Antillean' subspecies, while those in the continental U.S. are the 'Florida' subspecies. Although the distinction had been based on different physical traits observed in the two types of manatees, this study confirms that there is indeed a strong genetic basis to those differences.

The research offers a clearer picture of breeding relationships because the research team compared Florida and Puerto Rico using nuclear DNA, which provides enough granular detail about diversity to draw conclusions about current breeding rates. Earlier genetic data on West Indian manatees came from analysis of mitochondrial DNA, a type of genetic material typically used to understand a species’ ancient migratory past.

Among other findings in the study is the existence of two manatee populations within Puerto Rico itself that do not frequently interbreed. The two genetically different groups provide diversity that may improve the long-term prospects for manatees in Puerto Rico.

"This study provides solid data that allows us to better understand what Puerto Rico’s manatee population faces internally to survive…both as individuals and as a population. It also directs us in developing and implementing future studies in health assessments and habitat use that will enhance current conservation efforts in the island on behalf of the species," said co-author Antonio Mignucci, Ph.D., director of the Puerto Rico Manatee Conservation Center and research professor at Inter American University of Puerto Rico.

Puerto Rico's manatees are not only isolated from Florida’s population, but have little chance of receiving migrants from other nearby islands. The USGS has been working with the PRMCC and other biologists in Caribbean nations to gather new data about causes of death, habitat use, and breeding among manatees found on the surrounding islands. At this point, Jamaica and the Dominican Republic are believed to have small manatee populations while Guadeloupe, Haiti and the Virgin Islands have no known manatees.

"The more that we continue to learn about this unique mammal, the better we can enable managers to make decisions that ensure adequate protection," said Bob Bonde, Ph.D., a USGS research biologist and co-author of the research.

The study, "Puerto Rico and Florida manatees represent genetically distinct groups," is available online in the journal Conservation Genetics.

Florida and Illinois Make 48

OC_Web@usgs.gov (Office of Communications and Publishing) — Wed, 19 Sep 2012 8:00:00 EDT

With the release of US Topo maps for Florida and Illinois, the continental US is now covered with the new digital quadrangles

People who want access to digital topographic maps for any of the lower 48 states can now count on the US Topo. The ongoing map project, as part of the U.S. Geological Survey's national map series, recently released new maps for Florida and Illinois – with Hawaii to soon follow. Adding more than 2,015 revised digital quadrangles has increased the collection to nearly 54,000 new US Topo maps, with plans for Alaska developing. The maps are available for free download from The National Map and the USGS Map Store website.

"USGS topo maps are one of our most recognizable agency products, full of useful, up-to-date information, free, and easily downloaded to your computer," said USGS Director Marcia McNutt. "Don't leave home without US Topo."

Other new feature additions and improvements on the updated US Topo maps include:

Contours
Rivers, lakes steams and other hydrography
Woodland tint derived from the National Land Cover Dataset
Fire Stations
Hospitals
State and County boundaries
Forest service boundaries
Commercial roads in lieu of Census roads
Forest Service roads and road numbers

"We are pleased to fulfill our commitment to the public, and ahead of schedule", said Mark DeMulder, the Director of the USGS National Geospatial Program. "With the completion of the lower 48 states, we can retire the pilot 'Digital Map-Beta' maps and start on the second national revision cycle."

"During the past year, more than 3,000 US Topo were downloaded every day, and that number continues to increase", explained Mike Cooley, the US Topo Project Manager. "We believe the US Topo program has been a success and we would love to hear what our customers are thinking. Please consider visiting our US Topo contact page and let us know how we are doing."

US Topos are derived from key layers of geographic data found in The National Map which delivers visible content such as high resolution aerial photography, which was not available on older paper-based topographic maps. The new US Topo maps provide modern technical advantages that support wider and faster public distribution and on-screen geographic analysis tools for users.

Future enhancements to the US Topo are scheduled to include additional tools and map content such as a shaded relief layer, updated structures, enhanced transportation, additional federal boundaries, and Forest Service trails. Wyoming, which was added about three weeks ago, also featured Public Land Survey System (PLSS). The USGS expects to produce more than 18,500 revised quadrangles annually. US Topo maps are updated every three years.

The new digital electronic topographic maps for these new states– along with 46 other completed states - are delivered in GeoPDF image software format and may be viewed using Adobe Reader, also available as a no cost download.

For more information, visit A New Generation of Maps website.

One Click Away: Finding Data on Florida's Endangered Species Just Got Easier

OC_Web@usgs.gov (Office of Communications and Publishing) — Tue, 18 Sep 2012 9:50:58 EDT

Davie, FL. -- A new online tool will make data on several of Florida’s threatened and endangered species—including the Florida panther, American crocodile, and Key deer—more readily accessible to resource managers and planners.

The tool, a searchable database known as "Threatened and Endangered Vertebrates in Florida," was developed by a team of researchers from the University of Florida, the U.S. Fish and Wildlife Service, the U.S. Geological Survey, and the National Park Service.

It allows scientists and conservation managers to query an online database housing key scientific facts about the biology and ecology of 26 species of federally-listed threatened and endangered terrestrial vertebrates in Florida. The database query tool can be accessed online.

“We were gathering data for a project to assess how species respond to climate variables when we realized how valuable it would be to other scientists and managers if we could develop a tool to make the data more accessible," explained research ecologist Stephanie Romañach, PhD, who works for the USGS Southeast Ecological Science Center.

By querying the database, users will be able access species-specific information that can be used to guide research projects, develop ecological models, conduct species vulnerability assessments, and inform conservation action plans. The database includes almost 10,000 lines of data grouped into 10 major categories based on important biological traits, including reproduction, migration, and dispersal, as well as species’ relationships to climate variables such as temperature, precipitation, salinity, and responses to extreme weather.

"It is an incredibly useful tool for anyone wanting to learn more about some of the Florida's wildlife," said Larry Williams, South Florida Ecological Service Field Supervisor with the U.S. Fish and Wildlife Service. "This enhanced research capacity will undoubtedly contribute greatly towards all of our efforts to protect and preserve the natural wonders of Florida for future generations."

The database was implemented by the Advanced Applications Group at the USGS National Wetlands Research Center, and has been made available to the public by Joint Ecosystem Modeling (JEM), a partnership among federal and state agencies, universities, and other organizations. JEM activities include the monitoring and management of wildlife populations, understanding species responses to ecosystem restoration, and developing decision-support tools for restoration decision-making.

"Science excellence and collaborative partnerships are two pillars of our wildlife conservation culture," said Williams "This database enhances our ability to share and gather science from a wider spectrum of partners to the benefit of the imperiled species we're recovering across Florida."

The research team who developed the database links science to management by developing tools that support restoration and management decisions, species conservation, and climate change issues. Their approach includes the application of species distribution models to forecast the effects of land use, habitat alteration, and climate change on at-risk species, the use of life-history assessments to understand trait-mediated species responses to climate change and disturbance, incorporating climate sensitivities into species habitat and population models, and the assessment of species vulnerability to sea-level rise.

For more information about the JEM team’s projects, visit the JEM website or the University of Florida Institute of Food and Agricultural Sciences CrocDocs website.

USGS Storm-Surge Sensors Deployed Ahead of Isaac

OC_Web@usgs.gov (Office of Communications and Publishing) — Tue, 28 Aug 2012 17:59:21 EDT

Hurricane response crews from the U.S. Geological Survey are installing more than 120 storm-tide sensors at key locations along the Gulf Coast from the Florida Panhandle to Louisiana in advance of the arrival of Hurricane Isaac.

The storm-tide sensors, frequently called storm-surge sensors, will be secured to piers and poles in areas where the hurricane is expected to make landfall. The instruments being installed will record the precise time the storm-tide arrived, how ocean and inland water levels changed during the storm, the depth of the storm-tide throughout the event, and how long it took for the water to recede.

"While every hurricane brings the possibility for devastation, it also brings a learning opportunity by capturing valuable scientific data that improves our understanding of the pattern and timing of storm-driven coastal inundation," said USGS Director Marcia McNutt. "This vital information will help reduce loss of life and property now and in future events."

Storm-tides are increases in ocean water levels generated at sea by extreme storms and can have devastating coastal impacts. In locations where tidal forecasts are known, the sensors being installed can also help determine storm surge. For differences between storm-surge and tidal-surge, visit the National Hurricane Center's website.

This information will be used to assess storm damage, discern between wind and flood damage, and improve computer models used to forecast future coastal inundation.

In addition, rapid deployment gauges will be installed along critical roadways to provide real-time information to forecast floods and coordinate flood-response activities in the affected areas. The sensors augment a network of existing U.S. Geological Survey gauging stations already in place before the storm arrives.

Of the sensors deployed, 12 of those have real-time capability that will allow viewing of the storm-tide as Hurricane Isaac approaches and makes landfall. The real-time gauges have water level, precipitation and wind sensors that will transmit all data hourly. All gauge data can be found at the USGS Storm-Tide Mapper.

Providing information to support future forecasts could ultimately save lives during future storms. These sensors were deployed for the first time during Hurricane Rita in 2005. Before then, scientists had limited data available to study the effects of storm surge.

"Forecasters at the National Weather Service rely on USGS real-time and long-term data for input into its predictive models that are used to improve storm surge models and prepare storm-tide warnings," said Brian McCallum, assistant director of the USGS Georgia Water Science Center. "Floodplain managers, federal, state and local emergency preparedness officials, emergency responders, scientists and researchers all benefit from the storm-tide and associated flood data. It’s useful for flood damage prevention and public safety."

The USGS studies the impacts of hurricanes and tropical storms to better understand potential impacts on coastal areas. Information provided through the sensor networks provides critical data for more accurate modeling and prediction capabilities and allows for improved structure designs and response for public safety.

The USGS also continuously monitors water levels and flows at thousands of the nation's streams on a real-time basis. The public can access this information for their area at the USGS Current Streamflow Conditions web page. Also, USGS WaterAlert allows users to receive a text or email from the USGS when waters are rising in rivers and streams near them.

For the latest forecasts on the storm, listen to NOAA radio. For information on preparing for the storm, visit Ready.gov or Listo.gov

Isaac Expected to Change Sandy Coasts from Louisiana to Florida

OC_Web@usgs.gov (Office of Communications and Publishing) — Tue, 28 Aug 2012 16:58:32 EDT

Sandy beaches and barrier islands along the northern Gulf of Mexico are highly vulnerable to beach and dune erosion as Hurricane Isaac makes landfall this week, according to a new U.S. Geological Survey assessment. The projections also show which coastal areas may see storm-surge topping sand dunes and beaches.

Probabilities for coastal change have been calculated for parts of the Louisiana, Mississippi, and Alabama coastlines and for the Florida Panhandle.

On Saturday, the USGS released an assessment of expected coastal change in Florida, but the change in the storm’s path has reduced the concern for erosion of west central Florida beaches, shifting focus primarily to sandy beaches and barrier islands from Florida’s Panhandle to Louisiana.

Beaches and dunes can serve as a first line of defense for residents on coasts exposed to these types of storms. During tropical storms and hurricanes, elevated water levels and waves can lead to dramatic coastal change. According to the latest USGS research, during even the weakest hurricanes, wave height and storm surge combine to increase water levels along the Gulf Coast shoreline by 14 and a half feet higher than their normal levels.

"We can now combine more accurate coastal data with powerful new scientific models to provide the very best predictions of hurricane surge, waves, and erosion," said USGS Director Marcia McNutt. "USGS scientists used the latest NOAA forecasts to ensure that the people of the Gulf Coast are not surprised by the impacts of Isaac."

Using a USGS-developed model, scientists incorporated measurements of beach elevation and wave and surge forecasts from the National Oceanic and Atmospheric Administration to determine the probabilities of collision, overwash and inundation during the coming storm.

Collision is when waves attack the base of dunes and cause dune-front erosion. Overwash occurs when waves and storm surge overtop dunes and transport sand landward. Inundation, the most extreme of the three, occurs when increased water levels completely submerge beaches and dunes.

"Earlier this year, USGS released a report detailing hurricane induced erosion hazards for category 1-5 storms. The predictions released this week are based on the same methods, but tailored to waves and storm surge specific to Hurricane Isaac," said Hilary Stockdon, USGS research oceanographer. "As the storm moves across the Gulf, we use real-time storm and wave forecasts from NOAA to determine where beach erosion and inundation are most likely to occur."

These predictions, available on the USGS Hurricanes and Extreme Storms website, show the probable impacts of Isaac at each location along the coast. This assessment may be updated if there are significant changes in the storm’s projected track or strength. Based on the current assessment, the percentages of each type of coastal change were estimated for each of the following states:

Louisiana

Beach and dune erosion is very likely for 66 percent of Louisiana's sandy beaches
29 percent of the sandy beaches in this area are very likely to experience overwash.
18 percent of the Louisiana's barrier islands are expected to be inundated; however, the majority of this inundation will occur only on Louisiana's Chandeleur Islands.
100 percent of the Chandeleur Islands are very likely to experience overwash and 83 percent of these islands are very likely to be inundated. This beach system was devastated during Hurricane Katrina, making it more vulnerable to-low intensity storms.

Mississippi

Beach and dune erosion is very likely for 89 percent of Mississippi's sandy beaches and barrier islands.
20 percent of the sandy beaches are very likely to experience overwash.
Inundation of the beach system is not expected.

Alabama

Beach and dune erosion is very likely for 52 percent of Alabama's sandy beaches and barrier islands.
11 percent of the sandy beaches are very likely to experience overwash.
3 percent of the sandy beaches are very likely to be inundated

Florida Panhandle

Beach and dune erosion is very likely for 32 percent of the Panhandle's sandy beaches
2 percent of the sandy beaches are very likely to experience overwash.
Inundation of the beach system is not expected.

After the worst of the storm passes, USGS may send teams to the field to measure the impact of Hurricane Isaac on the coastline.

Aerial photography and elevation surveys of post-storm beach conditions are used to document the impacts of hurricane waves and currents on the beach. Information obtained from the surveys allows scientists to discern the degree of changes to beaches and coastal environments and determine how much the land has eroded and where new inlets have cut through. The newly acquired data will also be used to make more accurate predictive models of future coastal impacts from severe storms and identify areas vulnerable to extreme coastal change.

The areal photos can visually demonstrate the severe impacts of hurricane surge on beaches. This photo shows the effects that hurricane waves and surge have had on Dauphin Island, Alabama from 2004 -2008.

In May, the USGS released a report assessing probability of coastal change for the Gulf Coast when facing hurricanes of different strengths. The report included an interactive map that allows users to focus on different parts of the Gulf Coast shoreline to view how the probability of erosion, caused by waves and storm surge, will vary depending on hurricane intensity.

For the latest forecasts on the storm, listen to NOAA radio. For information on preparing for the storm, visit Ready.gov or Listo.gov

Florida Beaches and Dunes Face Erosion Risk During TS Isaac

OC_Web@usgs.gov (Office of Communications and Publishing) — Sat, 25 Aug 2012 14:30:00 EDT

USGS Calculates Likelihood of Coastal Changes

ST. PETERSBURG, Fla. – Seventy-eight percent of Florida's west central coast and 23 percent of the Panhandle are very likely to face beach and dune erosion as Tropical Storm Isaac moves into the area early next week, according to an assessment released by the U.S. Geological Survey on Friday. These numbers are likely to increase if the storm reaches hurricane strength as predicted.

For many Florida beaches that had significant erosion during Tropical Storm Debby in June, the impact of additional erosion may be even more significant.

"With Isaac bearing down on Florida beaches so soon on the heels of Debby, this is like a 'one-two punch' for the dunes that provide coastal protection," said USGS Director Marcia McNutt. "As these sand dunes dynamically morph to new configurations, our science-based models can help in forecasting where communities are at most risk from storm damage in this ever-changing spatial and temporal pattern of storm intensity and coastal morphology."

During tropical storms and hurricanes, elevated water levels and waves can lead to dramatic coastal change through erosion of beaches and dunes. These beaches and dunes can serve as a first line of defense for residents for many coasts exposed to these types of storms.

Using a USGS-developed model scientists incorporated measurements of beach elevation and wave and surge forecasts from the National Oceanic and Atmospheric Administration to determine the probabilities of collision, overwash and inundation during the coming storm.

"Tropical Storm Debby eroded many beaches along Florida's west central coast, impacting the property of many gulf-side residents and hotels," said Hilary Stockdon, a USGS oceanographer and lead of the assessment team. "Beaches typically take years to recover from severe storm impact, so having what is likely to be a Category 1 or 2 hurricane move up the coast just two months later could take a heavy toll on some already heavily eroded areas."

In addition to the likelihood of erosion, the team found that 15 percent of the west central coast was very likely to face overwash should the storm make direct landfall there, while that likelihood was only 5 percent for the Panhandle where dune elevations are higher. Unless forecasts change significantly, inundation is not expected in either area.

The team will revise its calculations as storm track and intensity forecasts are updated, and will update their projections and website accordingly. They plan to include the Alabama and Mississippi coasts in their assessments this weekend. Additional information on coastal change and extreme storms can be found on the USGS Coastal Change Hazards website.

The research is expected to help emergency managers at local, state and federal levels as they prepare for hurricane events such as this one in this and future seasons. Planners will be able to determine how different categories of hurricanes would impact their beaches and surrounding communities, helping them better protect lives and property.

For the latest forecasts on the storm, listen to NOAA radio. For information on preparing for the storm, visit Ready.gov or Listo.gov.

Flooding For Some Not Over

OC_Web@usgs.gov (Office of Communications and Publishing) — Thu, 28 Jun 2012 17:00:00 EDT

Streamgages Show Some Waters Still Rising

While many Florida residents breathed a collective sigh of relief Wednesday after Tropical Storm Debby made its way across the state and into the Atlantic, officials caution that flooding may continue in some locations for a number of days.

Crews from the U.S. Geological Survey's Florida Water Science Center continue their work in the field measuring high-water marks, determining flood levels reached and repairing damaged or destroyed streamgages throughout Florida.

The streamgages are critical to measuring actual river levels and flows, providing emergency managers information they need as they consider their flood response. The USGS operates more than 500 streamgages throughout Florida, measuring water levels, streamflow and rainfall.

One gauge on the St. Mary's river registered the highest peak on record since the gauge began operations on that river in 1927, beating the old record by 25 percent. Wednesday night the National Weather Service in Jacksonville issued a River Flood Emergency for the river and its tributaries in northeast Florida and Southeast Georgia after the USGS gauge at St. Mary's River at McCClenny registered a flow rate of near 36,000 cubic feet per second. The river is expected to peak downstream from McCClenny in 24 to 36 hours.

The National Weather service has also issued flood warnings for the Anclote river at Elfers; Cypress Creek at Worthington Gardens; the Alafia River at Lithia; the Little Manatee River at Wimauma; the Manatee River near Myakka Head; and the Myakka River at Myakka River State Park.

The alerts are updated continuously, so people looking for the latest information should go to NOAA's National Weather Service website or listen to NOAA weather radio.

Throughout the state, the slow moving storm caused flood levels many residents had never seen, setting records at several locations. At least nine streamgages operated by the USGS set records, although about half had only been operating for about 15 years, making their records a little less significant.

Streamgages on the Sopchoppy River near Sopchoppy, and the Little Manatee River near Wimauma, were destroyed and will be rebuilt, while about a dozen gauges throughout the state required minor repairs or maintenance.

In the Tampa – St. Petersburg area rainfall averaged about 15 inches, causing many low lying coastal areas to experience flooding from rivers and tidal surge. Several USGS coastal river gauges measured water levels about two feet over normal high tides. This combined with rivers at high levels like Anclotte River near Elfers -- which was 18 feet higher than before the rains started and 6 feet above flood stage – to cause widespread flooding.

Total cumulative rainfall was reported to be near 26 inches in some areas of central Florida, with more exact assessments coming.

"We're going to have to watch the water levels over the next few months pretty carefully," said Richard Kane, a USGS hydrologist and data chief at the USGS Florida Water Science Center in Tampa. "Some of our river levels are much higher than normal, and it will take some time before the water they are drawing from -- both the surface and the elevated groundwater levels -- return to normal. Until they do, another large storm or heavy rain event could trigger flooding fairly quickly in some areas."

Raging rivers and storm surge were not the only issue the public had to deal with, as the heavy rains following drought conditions resulted in some sinkholes developing throughout central and northern Florida.

Between 30 and 40 USGS responders from Tampa, Orlando and Tallahassee have been in the field daily since June 25 taking streamflow measurements, and recovering or repairing damaged streamgage equipment.

During storms, USGS information on streamflow is vital for savings lives and property, and is used by the U.S. Army Corps of Engineers to manage flood control, the National Weather Service to develop flood forecasts, and various state and local agencies in their flood response activities.

For more than 125 years, the USGS has monitored flow in selected streams and rivers across the U.S. The information is routinely used for water supply and management, monitoring floods and droughts, bridge and road design, determination of flood risk, and for many recreational activities.

People can access current flood and high flow conditions across the country by visiting the USGS WaterWatch website, and receive instant, customized updates about water conditions in their area via text message or email by signing up for USGS WaterAlert.

Gulf Coast Vulnerable to Extreme Erosion in Category 1 Hurricanes: New Model to Help Community Planners, Emergency Managers

OC_Web@usgs.gov (Office of Communications and Publishing) — Wed, 30 May 2012 8:30:00 EDT

Seventy percent of the Gulf of Mexico shoreline is vulnerable to extreme erosion during even the weakest hurricanes, according to a new report by the U.S. Geological Survey released just prior to the start of the 2012 hurricane season.

USGS scientists used state-of-the-art modeling to determine the probabilities of erosion, overwash and inundation during direct hurricane landfall for sandy beaches along the entire U.S. Gulf Coast shoreline.

The research is expected to help emergency managers at local, state and federal levels as they prepare for hurricane events in this and future seasons. Planners will be able to determine how different categories of hurricanes would impact their beaches and surrounding communities, helping them better protect lives and property. The report also includes an interactive map that allows users to focus on different parts of the Gulf Coast shoreline to view how the probability of erosion, caused by waves and storm surge, will vary depending on hurricane intensity.

"The Gulf Coast's beaches provide abundant recreational opportunities, contribute substantially to the local economy, and demand the highest real estate values," said USGS Director Marcia McNutt. "This important research raises awareness on the specific nature of the vulnerability of these beautiful beaches to impacts from even Cat-1 hurricanes so that property damage can be minimized through proper planning."

In a storm, high waves and storm surge can act together to erode beaches and inundate low-lying lands; during hurricane landfall, these changes can sometimes be catastrophic.

"Beaches along the Gulf of Mexico are extremely vulnerable to erosion during hurricanes, in part, because of low elevations along the coast," said Hilary Stockdon, a USGS research oceanographer and lead author of the study. "For example, the average elevation of sand dunes on the west coast of Florida is eight feet. On Florida’s Atlantic coast, the average is 15 feet."

During the landfall of a category-1 storm, where winds are between 75 and 94 miles per hour, overwash is very likely for 70 percent of Gulf Coast beaches. Overwash occurs when waves and storm surge overtop dunes and transport sand landward. Overwash is likely at these locations because of increased water levels at the shoreline. During category-1 hurricane events on the Gulf Coast, wave height and storm surge combine to increase water levels at the shoreline by 14 and a half feet higher than their normal levels.

"People continue to build communities in coastal areas that shift and move with each passing storm," said Stockdon. "This model helps us predict the potential impact of future storms and allows us to identify where the most vulnerable areas are located along the coast."

Additional findings from the report show that during a category-1 storm landfall, 27 percent of sandy beaches along the U.S. Gulf of Mexico are projected to be inundated, which occurs when increased water levels completely submerge beaches and dunes. If category-5 storms occur, where winds are 157 miles per hour or higher, 89 percent of these beaches are likely to be inundated during a direct landfall.

USGS scientists used methodology developed from a decade of USGS research on storm-driven coastal change hazards as the basis for these calculations. Observational data were combined with sophisticated hydrodynamic modeling to predict the coastal changes provided in the report. As new data and storm predictions become available, the report's analysis will be updated to describe how coastal vulnerability may change in the future.

Key findings and the full report are available online.

A similar report detailing erosion hazards along the east coast is planned later this year. This report will provide an assessment of vulnerability for east coast barrier island communities.

Rise in Asian Tiger Shrimp Sightings Prompts Scientific Look at Invasion Concerns

OC_Web@usgs.gov (Office of Communications and Publishing) — Thu, 26 Apr 2012 11:00:00 EDT

Additional Contact: Keeley Belva, NOAA 301-713-3066 Keeley.Belva@noaa.gov

Content updated - 4/26/2012 6:48 pm

GAINESVILLE, Fla. – The recent rise in sightings of non-native Asian tiger shrimp off the U.S. Atlantic and Gulf of Mexico coasts has government scientists working to determine the cause of the increase and the possible consequences for native fish and seafood in those waters.

Researchers from the U.S. Geological Survey and National Oceanic and Atmospheric Administration are working with state agencies from North Carolina to Texas to look into how this transplanted species from Indo-Pacific, Asian and Australian waters reached U.S. waters, and what the increase in sightings means for native species.

"We can confirm there was nearly a tenfold jump in reports of Asian tiger shrimp in 2011," explained Pam Fuller, the USGS biologist who runs the agency's Nonindigenous Aquatic Species database. "And they are probably even more prevalent than reports suggest, because the more fisherman and other locals become accustomed to seeing them, the less likely they are to report them."

NOAA scientists are launching a research effort to understand more about the biology of these shrimp and how they may affect the ecology of native fisheries and coastal ecosystems. As with all non-native species, there are concerns over the potential for novel avenues of disease transmission and competition with native shrimp stocks, especially given the high growth rates and spawning rates compared with other species.

"The Asian tiger shrimp represents yet another potential marine invader capable of altering fragile marine ecosystems," said NOAA marine ecologist James Morris. "Our efforts will include assessments of the biology and ecology of this non-native species and attempts to predict impacts to economically and ecologically important species of the Atlantic and Gulf of Mexico."

The cause of the rapid increase in sightings remains uncertain, Fuller added. The non-native shrimp species may have escaped from aquaculture facilities, although there are no longer any known Asian tiger shrimp farms presently in operation in the United States. It may have been transported in ballast water from ships or possibly arrived on ocean currents from wild populations in the Caribbean or other locations.

Fuller's team at USGS has been tracking reports of Asian tiger shrimp since they first came to the attention of marine scientists and resource managers in 1988, when nearly 300 of them were collected off the coasts of South Carolina, Georgia and Florida within three months. Scientists tracked the cause back to an isolated incident that accidentally caused an estimated 2,000 animals to be released from an aquaculture facility operating at that time in South Carolina.

It was not until 18 years later that reports of the non-native shrimp resurfaced. In 2006, a commercial shrimp fisherman caught a single adult male in Mississippi Sound near Dauphin Island, Ala. Within months, additional specimens were noted in North Carolina’s Pamlico Sound, Louisiana’s Vermilion Bay and other parts of Florida and the Carolinas. The species was later reported off the coasts of Georgia, Mississippi and Texas in 2008, 2009 and 2011, respectively.

Scientists have not yet officially deemed the Asian tiger shrimp "established" in U.S. waters, and no one is certain what triggered the recent round of sightings. With so many alternative theories about where these shrimp are coming from and only a handful of juveniles reported, it is hard for scientists to conclude whether they are breeding or simply being carried in by currents.

To look for answers, USGS and NOAA scientists are examining shrimp collected from the Gulf and Atlantic coasts to look for subtle differences in their DNA, information that could offer valuable clues to their origins. This is the first look at the genetics of wild caught Asian tiger shrimp populations found in this part of the U.S., and may shed light on whether there are multiple sources.

"We're going to start by searching for subtle differences in the DNA of Asian tiger shrimp found here – outside their native range –to see if we can learn more about how they got here," said USGS geneticist Margaret Hunter, "If we find differences, the next step will be to fine-tune the analysis to determine whether they are breeding here, have multiple populations, or are carried in from outside areas."

Anyone who sees one or more shrimp suspected to be an Asian tiger shrimp is asked to note the location and report the sighting to the USGS NAS database. If possible, freeze a specimen to help confirm the identity and contribute to a tissue repository maintained by NOAA.

The USGS serves the nation by providing reliable scientific information to describe and understand the Earth; minimize loss of life and property from natural disasters; manage water, biological, energy, and mineral resources; and enhance and protect our quality of life.

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NOAA Center for Coastal Fisheries and Habitat Research Invasive Species

Tampa USGS Office to Move

OC_Web@usgs.gov (Office of Communications and Publishing) — Mon, 5 Mar 2012 10:00:00 EDT

TAMPA, Fla. -- The Tampa office of U.S. Geological Survey Florida Water Science Center will relocate from its current location near the University of South Florida to an industrial park in Lutz in August.

The move is being made to strengthen larger statewide efforts to streamline the agency’s organizational structure, increase operational efficiency and better serve resource managers and environmental stakeholders of west-central Florida. The new facility, located in Compark 75 at 4450 Pet Lane in Pasco County, will house 60 employees, including hydrologists, hydro-technicians and support staff. In total, the center has 150 employees located in Davie, Orlando, Tallahassee, Ft. Myers and Tampa.

The USGS is the Nation's largest earth science agency that provides a scientific understanding about natural resource conditions, issues and problems. The Florida Water Science Center’s mission is to collect, analyze and disseminate the impartial hydrologic data and information needed to wisely manage water resources for the Nation and the State of Florida.

Throughout Florida, the USGS operates a network of stream flow and flood stage monitoring stations that help forecast future floods, track rising water due to rain or storm surge, and monitor water quality and availability, said Rafael W. Rodriguez, director of the center.

“Although Florida is a relatively water-rich state, in some locations increasing water use may be exceeding the sustainable yield of supplies. Add shortages caused occasionally by short-term drought, competing needs of increases in population and development, some supplies being restricted due to contamination, and other draws on the supply, and you can see how important it is we have reliable and accurate information available to ensure a safe and sustainable water supply that meets all of Florida’s needs," Rodriguez said. "That’s what these networks provide."

The center’s science investigation programs focus on the occurrence, fate, and transport of contaminants in the environment, predicting changes in the quality and quantity of water resources in response to a changing climate and landscape, and advancing the understanding of the interrelations of groundwater and surface water and their role in Florida’s wetland ecology. The center utilizes a variety of numerical models and other advanced mathematical techniques to support the water resources informational needs of Federal, state and local users. Investigative studies follow an integrated philosophy, where model development work functions hand-in-hand with visualization technology, physical experimentation, and field reconnaissance and surveillance.

Scientists Measure Carbon And Mercury Coming Out Of South Florida Mangroves

OC_Web@usgs.gov (Office of Communications and Publishing) — Wed, 15 Feb 2012 12:00:00 EDT

HOMESTEAD, Fla. -- For the first time, scientists have measured the amount of dissolved organic carbon and mercury moving from a southwest Florida mangrove swamp via tides to coastal waters. The scientists from the U.S. Geological Survey discovered that a large amount of mercury and methylmercury–the form of mercury that is most toxic and the form that accumulates in fish–flows from mangroves into the Gulf of Mexico.

According to the South Florida Water Management District, over 50 species of fish in Florida's coastal waters have elevated concentrations of mercury, and human health advisories regarding consumption have been issued by the Florida Department of Health for several fish species in Florida coastal marine areas. A greater understanding of the sources and environmental pathways resulting in these elevated methylmercury concentrations in fish will help environmental managers, policy makers, and regulators lower human and wildlife mercury exposure.

"Previous USGS research has revealed that these swamps transform mercury to its toxic methylmercury form far from the coal-burning plants that are the original source of the pollution," said USGS Director Marcia McNutt. "Now we are learning that the threat to wildlife and human health does not stop there, but is carried out to sea on the ebb tide."

Scientists pioneered a new high-frequency measurement method to measure dissolved organic carbon, mercury and methylmercury in an extremely complex tidal estuarine environment. The study originated from the need to measure the flux of dissolved organic carbon, but scientists realized that they could simultaneously measure mercury and methylmercury using the same techniques. Previous USGS research in the Everglades has shown that methylmercury and mercury bind to dissolved organic carbon.

Study results revealed that mercury from the mangroves could account for over 90% of the methylmercury and almost half the total mercury supply to the near-shore coastal waters of southwestern Florida. The study's findings represent an important first step in identifying and quantifying a significant source of mercury and methylmercury for coastal fish in southwest Florida-Gulf of Mexico region. The findings are published in the journal Environmental Science & Technology.

Although almost all of the mercury entering the Gulf of Mexico originates from the atmosphere, it is not understood how or where this mercury undergoes the necessary conversion to its more toxic form, methylmercury. Scientists do not understand the relative contribution, but generally agree that the conversion to methylmercury occurs in the following three areas:

in the landscape, where it could be flushed into coastal areas by runoff and tidal pumping;
in the estuarine zones, which in southwest Florida often contain mangroves, where it could be flushed into the coastal areas by the tides; or,
in the deep open waters and/or bottom sediments of the Gulf of Mexico.

Until now, the amount of methylmercury coming from estuarine mangrove zones into the coastal areas was unknown because making accurate measurements of this type is extremely challenging. The tide waters that flow in and out of the estuary twice a day must be measured in addition to the constantly changing dissolved organic carbon, mercury, and methylmercury concentrations that result.

"Once we understand where the mercury is being methylated, and how much methylmercury is coming from various environments, resource managers, regulators, and decision makers will be better able to anticipate how the Gulf of Mexico will respond to reductions in mercury loads. It's a very important start that we at least have one of the rivers, the Shark River, flowing into the Gulf of Mexico, quantified as to how much mercury, methylmercury and dissolved organic carbon, is flowing into the gulf," said USGS researcher David Krabbenhoft.

Researchers believe that a relatively unique combination of circumstances result in the large amounts of methylmercury they measured flowing from mangroves into the coastal ocean. Mangroves forests capture gaseous mercury from the air through their leaves and drop them into the brackish swamp waters, where methylmercury is produced in the presence of seawater sulfate.

"Measuring the amount of mercury that mangrove swamps contribute to coastal waters will help us understand and model the sources of mercury that enter the food web," said lead researcher Brian Bergamaschi with the USGS.

This study is the work of scientists from the USGS, Florida Gulf Coast University, and the State of Florida. The high-frequency dissolved organic carbon measurement methodology was developed for a previous study in San Francisco Bay.

The USGS has studied mercury in the Everglades since 1994. Previous USGS research discovered that mercury in the Everglades was coming from atmospheric releases and deposition, and not from natural land sources such as rocks. They also found that the formation of methylmercury in the Everglades is strongly influenced by land and water uses, including the delivery of sulfate from up-gradient agricultural lands. This study represents a significant contribution to the knowledge about the risks of mercury exposure in south Florida, but additional studies are necessary to better understand how mercury accumulates in coastal fish.

For more information about mercury, please visit the USGS Mercury in the Environment webpage. For more information about carbon cycling and sequestration in terrestrial and marine environments, please visit the USGS LandCarbon website.

Satellite Tracking Reveals Sea Turtle Feeding Hotspots

OC_Web@usgs.gov (Office of Communications and Publishing) — Wed, 1 Feb 2012 15:00:00 EDT

Study Offers Clues to Loggerheads' Elusive Habits at Sea

GAINESVILLE, Fla. – Satellite tracking of threatened loggerhead sea turtles has revealed two previously unknown feeding ‘hotspots’ in the Gulf of Mexico that are providing important habitat for at least three separate populations of the turtles, according to a study published recently in the journal Biological Conservation.

The two sites, located in the open waters off the coast of Southwest Florida and the northern tip of the Yucatan Peninsula, were found by a team of scientists when they compiled and analyzed loggerhead tracking data.

The researchers' goal was to synthesize tracking data from three genetically distinct loggerhead populations to learn more about how they use the Gulf of Mexico. By identifying the specific location of regularly used habitat, the results provide invaluable information for marine planning and management for this species, whose populations in the Gulf of Mexico are well below historic levels and in recent years have continued to decline drastically in some areas.

The maritime feeding grounds also hold the first clues about how loggerhead sea turtles spend time at sea – which is, in essence, most of their lives.

"Up until now, management actions that affect loggerheads have often focused on their limited time at nesting beaches, or on fisheries regulations," said Kristen Hart, Ph.D., the U.S. Geological Survey research ecologist who led the synthesis. "Our findings open up important new options for marine habitat conservation, and provide valuable geographic data that can be used to strategically locate marine reserves based on the best available science, as called for in the new National Ocean Policy."

"The use of satellite tags for tracking marine animals has opened our eyes to the secret lives of some of nature's most elusive creatures," said USGS director Marcia McNutt, "At first a scientific tool to understand the life cycle of animals, such as white sharks and leatherback turtles, who rarely come into contact with humans, these tags may now be the main hope for understanding what we can do, or what we should stop doing, in order to bring them back from the road to extinction."

Researchers intercepted female loggerheads after their nesting forays to beaches and outfitted them with satellite tags at study sites in the Florida Panhandle, Casey Key in southwest Florida, and Dry Tortugas National Park. They then tracked the females’ migrations and used a new method to determine precisely when they had arrived at "hotspot" foraging areas, in two geographically different locations.

Seven female turtles migrated to foraging sites off Southwest Florida, while the other three took up residence at foraging sites at the Yucatan site. Once the researchers applied the new method for synthesizing their satellite-tracking data, it became clear that these loggerhead turtles from all three populations consistently converged around two common sites. This confirmed a hunch that the researchers had developed after years of tracking turtles.

At both of the feeding hotspots, turtles selected individual sites where they foraged in shallow or nearshore waters less than fifty meters deep. Turtles appeared to prefer their own distinct territories, where they tended to remain resident. This suggests that it may be possible to accurately predict where sea turtles will feed, information that will prove vital for managers looking to focus conservation efforts on prime foraging habitat.

Researchers don't yet know what attracts loggerheads from around the Gulf to these specific feeding areas, although generally, loggerheads forage on the bottom of the sea floor for crustaceans such as crabs, lobsters, clams or conchs.

"The logical next step is to investigate what makes these particular sites 'prime' foraging grounds by mapping and sampling the habitat types found on the sea floor," explained Hart. "It would also be useful to tag loggerheads at these foraging sites to confirm how long they reside in these areas, or alternatively to see where they go next."