The open sandy beach is one of the hardest habitats to live in on a barrier island. There is no where to hide and almost nothing to eat. Add to this the direct wind and waves from the Gulf of Mexico and you have a barren landscape with continuous climate and ocean energy. But creatures do live here.
The beach is void of plant life and takes a well adapted animal to reside here.
Phot: Rick O’Connor
Before we go further let’s define a few terms. The beach is actually the dry sandy portion of this environment. The area where the sand squeaks as you walk through it, the place where you set your chairs, umbrellas, and lunch for your day at the beach. The berm is the harder packed sand near the waters edge. The place where you like walk when you walk the beach (it’s easier) and the waves wash over every few seconds. Living in these two would be very different. Second, we will define resident and transient. A resident is a creature who actually resides there. A transient is just passing through but lives somewhere else.
As you look across the beach you will notice there is NO WHERE to hide from the elements… except beneath the sand. One of the more common creatures who lives beneath the is the ghost crab (Ocypode quadrata). This crustacean digs burrows down to the water table where they can keep their gills wet and this can be as deep as four feet. On these flat beaches they are easy target for predators. They have several ways to deal with the problem. (1) Their compound eyes are on stalks above their head to give them a wider, and longer, range of view. (2) They are white in color and blend in with the quartz sand well. (3) They are more active at night, nocturnal. (4) They are very fast.
The trick to speed is to break contact with the ground. If you were to ask someone “what is the fastest way to get to Los Angeles?” They would answer “flying”, and this would be correct. Birds are some of the fastest creatures around. They fly. They lift off the ground and do not touch again until they reach their destination. It does not get any better than that. Cheetahs are very fast as well. But if you watch them in slow motion, you will see they are basically leaping from one point to the next. They touch the ground very few times over a certain distance. They are trying to fly but cannot. If look at video of a human, or centipede, or slug. Not sot good. Crabs are crustaceans and by definition they have 10 legs. When they move across the surface, they usually use eight of those (two being their claws). The same is true for the ghost crabs. But when they decide to run, they only run on three of them. They raise the other five above their heads. This means fewer legs touching the sand which means they are faster.
The common ghost crab. Photo: Virginia Institute of Marine Sciences
Food is another issue. Due to direct high wind (filled with salt), plants do not grow on the beach. Hence the classic food chain (plant – herbivore – carnivore) cannot exist. So, what do ghost crabs eat? They are scavengers. They emerge from their burrows, usually at night, to seek what dead creatures the tide may have washed in. Post storms are particularly good feeding times. Surf fishermen along the Gulf beach often catch hardhead catfish and, not liking them, often toss them on the beach to die. In the evening the ghost crabs will drag these to the entrance of their burrows where they feast for quite a while. They eventually clean to fish to the bone leaving their “hard head” (the skull). When you look at the skull from underneath it appears to be Jesus on the crucifix. These skulls are often collected and sold in novelty stores as “crucifix fish”.
The bones in the skull of the hardhead catfish resemble the crucifixion of Christ and are sold as “crucifix fish”.
Photo: Rick O’Connor
Another prize for ghost crabs are sea turtle eggs. Sea turtles are obvious transients to the beach environment, coming here only during nesting season. The females usually approach the beach close to where they were born at night. She will labor her way across the beach to the first dune line, though some will lay theirs in the open beach area. She could spend several hours digging a hole three to five feet deep. Loggerhead Sea Turtles (the most common on our beaches) simply dig a hole. The Green Sea Turtle will use her flippers to dig a form for her body before digging the nest. She will deposit about 100 eggs before burying them and returning to the Gulf. Ghost crabs, and other beach transients like coyotes, fox, and raccoons, will find and raid these nests.
Tracks left by a nesting Green Sea Turtle. Courtesy of Gulf Islands National Seashore.
The wrack (a line of debris that includes seaweed, shells, and other flotsam from the Gulf) offers a variety of food for ghost crabs. Another who is often found scavenging the wrack are shore birds. There are numerous species of terns, gulls, pipers, and plovers that will pick through the wrack for food.
The berm is a tougher place to make home. You are in the surf zone and must deal with breaking waves every few seconds. As you might expect, there are no plants here, and very few animals. Those that do reside here bury in the sand knowing that the surf will most likely expose them and could carry them to another location. The two most common animals in this zone are the mole crab and the coquina.
The mole crab is often called a “sand flea”.
Photo: Rick O’Connor
The mole crab (Emerita talpoida) is also known by surf fishermen as the “sand flea”. It is a small oval shaped crab that has a hard paddle like telson to dig into the wet sand tail first. With its head exposed it will extend antenna that are covered with small hair-like structures designed to collect plankton from the water that covers it when the waves come in. The surf often exposes them, but they flip over and dig back in very quickly.
The coquina (Donax variabilis) is a small clam that comes in a variety of colors (hence it’s species name). Like all clams, it has a fleshy foot which it uses to quickly dig into the wet sand covering most of its body. Like the mole crab, it exposes its head into the surf extending two fleshy tubes called siphons that draw water into the clam where it can collect planktonic food.
Coquina are a common burrowing clam found along our beaches.
Photo: Flickr
Predators do exist here, but they are not residents. They would include transient fish that come close to shore waiting for the surf to wash these small animals into the Gulf. One of the more common is the Florida Pompano. Surf fishermen like to use “sand flea” baskets, dragging them through the sand near the waters edge to capture the mole crabs for bait seeking these tasty fish. Others would include an assortment of shorebirds like sand pipers and plovers who run to the wet sand when the surf recedes back into the Gulf probing for the mole crabs and coquina, then quickly running back towards the beach when the surf returns.
A variety of shorebirds utilize the wrack. Photo: Rick O’Connor
The diversity of life in the beach-berm zone is not high, but this is a tough place to make a living. Ghost crabs, mole crabs, and coquina clams have all adapted to living here and have done quite well. But more wildlife prefers the dunes. It is a little easier there and the next stop in Part 5 of this series.
There are a lot of cool and interesting creatures that live on the barrier islands of Northwest Florida. The conditions out there require they make changes and adaptations different from what they would do in a more upland or wetland environment. Some creatures are unique to these beach and dune systems and found nowhere else. But to begin this series lets first look at the islands themselves.
The white beaches of the Florida panhandle are primarily quartz. Photo: Rick O’Connor.
The name barrier island comes from the fact that they do serve as a barrier between the open Gulf of Mexico and the mainland of the Florida panhandle, protecting coastal communities from storm surge and waves of the all too frequent hurricanes and tropical storms. They are basically sandbars formed with sands from the Appalachian Mountains. There the wind, rain, and temperature erode the granite rock into its mineral components and wash them downstream. First in the fast-moving mountain streams, then into creeks, into rivers which eventually discharge into the Gulf. The different minerals settle out based on their size, type, and densities. Quartz is one of the less dense and is the dominant mineral forming the coastal barrier islands, making them some of the whitest beaches on the planet.
When these quartz sands reach the Gulf, they encounter longshore currents that are formed from the winds blowing across the open water. In this part of the Gulf of Mexico these currents tend to move from the east to the west in most cases. As the rivers reach the passes that connect the estuaries to the open Gulf and the longshore currents move the sand into long thin spits at the mouth of the bays running parallel to the coastline. In some cases, the sand bars form perpendicular to the coastline, and we call them capes. Initially still connecting to land, many creatures can venture out on these sand spits searching for food. Some of the sand spits are very small and seem to come and go as the winds and waves move them. At times these smaller spits may actually close off the opening into the bay as they once did on Perdido Bay and still do with the Walton County dune lakes. In other cases, the spits accumulate more sand, become long and can eventually break contact with the mainland forming an island.
From the Pensacola Lighthouse you get a great view of the open Gulf and the eastern end of Perdido Key. Here the pass separates Perdido Key (on the left) and Santa Rosa Island. Photo: Molly O’Connor.
At first these islands can be nothing more than sand bars. Barely above sea level, moving and changing very quickly, sometimes disappearing and reappearing in slightly different locations after storms, such as Sand Island off Dauphin Island Alabama. In others they are larger, harder to move quickly and may be vegetated so that movement is slower and the island more established, such as Santa Rosa Island near Pensacola. The creatures on any of these islands will need to be able to adapt to the new conditions. Some will be able to leave and return the mainland when they need or want to. Birds are very common on all forms of barrier islands due to the fact they can fly. In some cases, the distance from the mainland is not a far swim for those who can, such at Indian Pass near St. Vincent Island. In some cases, the distance may not be as close and the currents between very swift during tide changes making crossing more difficult. In these cases, the creatures who find themselves on these islands must adapt to the new conditions or risk losing their populations entirely.
Island conditions can be tough. There is a lot of wind, and this wind carries salt spray. There is little cover from the intense sun during the summer months. Needed freshwater can be hard to find. Some islands will develop freshwater systems, but others will not. And then there is the fact that it is an island. Thus, a finite amount of resources and space for each species, and, at times, fierce competition for those.
In Part 2 we will explore the different habitats that developed on these islands that available for the different wildlife that exploit them.
The wind sculpted plants of the tertiary dunes. Photo: Rick O’Connor.
Since 2005 we have been tracking and monitoring diamondback terrapins in the Florida panhandle. For those of you who are not familiar with the animal, it is a turtle in the family Emydidae. Emydid turtles include what we call “pond turtles” and also include the box turtles. Terrapins differ from the others in that (a) their skin is much lighter, almost white, and (b) they like salt water – more accurately, they like brackish water.
Diamondback terrapin (photo: Molly O’Connor)
The animals range from Massachusetts to Texas and within this there are seven subspecies. Five of these live in Florida, and three only live in Florida. In the Florida panhandle we have two subspecies: the Ornate terrapin (Malaclemys terrapin macrospilota) and the Mississippi terrapin (M.t. pileata). It is believed the that the Mississippi terrapin only exist in Florida within Pensacola Bay – more on that in a moment.
Image provided by FWC
There are literally no peer reviewed publications on terrapins from the Florida panhandle… none. And this was how the Panhandle Terrapin Project began. The first objective for the project was to determine if terrapins even existed here. We began surveying for evidence of terrapins in 2005 using students from Washington High School in Pensacola. The project quickly fell to myself and my wife due to the best time to do terrapin surveys was May and June. And the worst time to work with high school students was May and June. Between 2005 and 2012 we were able to verify at least one terrapin record in each of the panhandle counties. Yes… terrapins exist in the Florida panhandle.
The second objective was to assess their population status. To do this we used what I call the Mann-Method. Tom Mann, Mississippi Department of Wildlife, had developed a method of using nesting surveys to estimate relative abundance of terrapins within a population. Terrapins tend to have strong site fidelity – they are “home bodies” – and do not move from marsh to marsh. If you can find their marsh, you can find their nesting beaches. If you can find their nesting beaches you can use the Mann-Method to assess their relative abundance.
Tracks of a diamondback terrapin.
Photo: Terry Taylor
There are a couple of assumptions with the Mann-Method. (1) You are assuming every female in the population nest every year – we are not sure that is true. (2) You are assuming that each female will lay more than one clutch of eggs each season – we do believe this is true. (3) You are assuming that each female will not lay more than one clutch in a 16-day period – we are not sure this is true. (4) You know where all of the nesting beaches are – we are not sure we do. (5) The sex ratio of male to female is 1:1 – we are sure that is not the case. One study suggested that in the panhandle the ratio may be 1:3 in favor of males, another suggested 1:5 in favor of males.
Based off this model, and its assumptions, during a 16-day period of the nesting season, each track/nest would be an individual female. Using 1:1, 1:3, and 1:5 as your sex ratio you can get an estimate of relative abundance.
Another method for estimating relative abundance is counting the number of heads in a 30-minute period. It is understood that if I see different heads during periods of the survey, I may be seeing the same head, but the argument is that if I typically see 10-15 heads during a 30-minute and over time that becomes 15-20, or 20-25, the relative abundance of terrapins is increasing – and visa versa.
A terrapin swimming near but not entering a modified crab trap.
Photo: Molly O’Connor
And we now have a third and fourth objective. A third objective is to capture animals to place tags on them. Doing this can give us a better idea of how these terrapins are using the habitats in the panhandle, how far they may travel and how they are getting there. The fourth objective is to obtain tissue samples for genetic analysis. The purpose of this is to determine whether the populations in Pensacola Bay are Mississippi terrapins, Ornate terrapins, or hybrids of the two.
Since 2015 this work is now being conducted by trained volunteer citizen scientists – people like you – and we do the trainings in March if interested.
So… how did things go in 2022?
In 2022 we trained 47 volunteers to be survey beaches. 25 (53%) participated in at least one survey.
173 surveys were conducted between April 2 and July 31 at 14 nesting beaches between Escambia and Bay counties. Encounters with terrapins, or terrapin sign, occurred during 43 of the 173 surveys (25%) and three terrapins were captured for tissue and tagging.
Escambia County
Number of Surveys
Dates
Number of Surveys / Day
29
Apr 3 – Jul 31
0.2
Number of Encounters
Frequency of Encounters
Heads / 30-minutes
Estimated Relative Abundance
4
.18
No surveys conducted
4-12
Santa Rosa County
Number of Surveys
Dates
Number of Surveys / Day
58
Apr 4 – Jul 5
0.6
Number of Encounters
Frequency of Encounters
Heads / 30-minutes
Estimated Relative Abundance
15
.26
N=2, 0-49, X = 24
30-90
Okaloosa County
Number of Surveys
Dates
Number of Surveys / Day
43
Apr 18 – Jul 15
0.5
Number of Encounters
Frequency of Encounters
Heads / 30-minutes
Estimated Relative Abundance
25
.58
N=17, 0-32, X = 11
30-90
No surveys were conducted in Walton County
Bay County
Number of Surveys
Dates
Number of Surveys / Day
43
Apr 2 – Jun 30
0.5
Number of Encounters
Frequency of Encounters
Heads / 30-minutes
Estimated Relative Abundance
0
.00
No surveys conducted
0
Summary of 2022 Terrapin Season
Surveys of nesting beaches occurred in four of the five counties in the western panhandle.
Terrapins were encountered in each of these cand captured in two of them.
The relative abundance ranged between 0 (Bay County) to between 30-90 individuals (Santa Rosa and Okaloosa counties) and was about 64-192 animals for the entire western panhandle (depending on the sex ratio you use).
We are sure that we have not found all of the nesting beaches in this region and will continue to look for more.
We are awaiting results from the tissue sampling to determine whether we have a distinct population of Mississippi terrapins in Pensacola Bay, but more samples will be needed.
We need to place satellite tags on some females to get a better idea of how they travel through the system.
And our relative abundance numbers suggest that populations in the Florida panhandle are relatively small compared to others within the terrapin range.
More needs to be done and we will continue to survey each spring. If you are interested in becoming a member of the Panhandle Terrapin Project, contact me (Rick O’Connor) at roc1@ufl.edu.
October is the premier wildflower month in the Panhandle. Nighttime temperatures drop, days shorten, pollinators emerge, and many native plants explode into flower. Of all the native fall-flowering Panhandle wildflowers, maybe the most striking is currently in full bloom, the Mistflower (Conoclinium coelestinum)!
Blue Mistflower. Photo courtesy of Bill Booth / Natural Encounters.
Mistflower is a low growing, spreading native (1-2’ in height) found in sunny, moist areas of meadows and near rivers, ponds, and creeks throughout much of the United States from New York to Florida and even west as far as Texas and Nebraska. This common native wildflower is conspicuously one of the few native plants in our area that has blue flowers, making Mistflower easy to spot in a sea of yellow, orange, purple, pink, and white wildflowers. The flowers appear as little puffs of purply-blue due to the lack of ray florets (think of the outer yellow “petals” of sunflowers), possessing only disk florets (think of the inner part of sunflower heads) with long blue, fuzzy-appearing stamens. Mistflower is attractive to more than just wildflower watchers as well, it’s a magnet for nectar-seeking butterflies such as the Eastern Swallowtails, Great Purple and Juniper Hairstreaks, and others.
Great Purple Hairstreak butterfly on Mistflower. Photo credit Bill Boothe / Natural Encounters.
As lovely as Mistflower is in the wild, it’s probably best left for folks enjoy there, especially those who prefer an orderly yard. Mistflower will indeed grow great in moist areas of pollinator gardens and landscapes, requiring only ample sunlight and rainfall, but it is very aggressive. Its spreading nature via its rhizomatous root system and prolific seed production often lead to it becoming a weedy nuisance in more manicured landscapes. But, if chaos and fall bursts of blue erupting at random throughout your garden don’t bother you, by all means, seek out Mistflower for purchase through seed catalogs and local native nurseries. For more information on Mistflower and other fall-blooming native wildflowers, contact us at the UF/IFAS Calhoun County Extension office! Happy Gardening.
¿Está interesado en hacer algo que beneficie a su comunidad marina local? ¡Disfruta de días al sol, como un “Scallop Sitter” (cuidador de las vieiras)!
“Scallop Sitters” (cuidador de vieiras) es uno de nuestros programas de voluntariado cooperativo con Pesca y Vida Silvestre de Florida (FWC, por sus siglas en inglés). Históricamente, las poblaciones de vieiras de la bahía eran muy numerosas y podían sustentar las pesquerías en muchas bahías del norte de Florida, incluidas la bahía de San Andrés, la bahía de San Juan y el Puerto de los Caimanes (Condado de Franklin). Años consecutivos de malas condiciones ambientales, pérdida de hábitat y “mala suerte” en general resultaron en una escasa producción anual y provocaron el cierre de la pesquería de vieiras. La vieira de la bahía es una especie de corta vida que pasa de ser una cría a adultos que desovan y muere en un año aproximadamente. Las poblaciones de vieiras pueden recuperarse rápidamente cuando las condiciones de crecimiento son buenas y pueden disminuir drásticamente cuando las condiciones de crecimiento son malas.
En 2011 se presentó la oportunidad de poner en marcha la restauración de las vieiras de la bahía del norte de Florida. Con la financiación del derrame de petróleo de Deepwater Horizon, se propuso un programa de restauración de vieiras en varios condados, que finalmente se estableció en 2016. Los científicos de Pesca y Vida Silvestre de Florida (FWC, por sus siglas en inglés) utilizan vieiras criadas en criaderos, obtenidos a partir de progenitores o reproductores de las bahías locales, para cultivarlas en masa y aumentar el número de adultos reproductores cerca del hábitat crítico de las praderas marinas.
La Pesca y Vida Silvestre de Florida (FWC, por sus siglas en inglés) también creó otro programa en el que los voluntarios pueden ayudar con la restauración llamado “Scallop Sitters” en 2018 e invitó a UF/IFAS Extension a ayudar a dirigir la parte de voluntarios del programa en 2019, lo que llevó a esfuerzos específicos en los condados del Golfo y la Bahía.
Para ayudar a las vieiras, los “Scallop Sitters” trabajan con UF/IFAS Extension, Florida Sea Grant y los científicos de restauración de la Pesca y Vida Silvestre de Florida (FWC, por sus siglas en inglés) limpiando las vieiras y comprobando la salinidad una vez al mes desde junio hasta enero. Foto de Tyler Jones, UF/IFAS Extension y Florida Sea Grant.
Después del hiato de 2020 debido a COVID-19, el programa presumió de casi 100 voluntarios para la campaña de 2021. UF/IFAS Extension se asocia de nuevo con Pesca y Vida Silvestre de Florida (FWC, por sus siglas en inglés) en los Condados de Bahía y Golfo y Franklin. A pesar de los retos que suponen las lluvias, la escorrentía de las aguas pluviales y la baja salinidad, nuestros voluntarios de Scallop Sitter han proporcionado información valiosa a los investigadores y a los esfuerzos de restauración, especialmente en estos primeros años de nuestro programa. Los “Scallop Sitters” recogen información útil sobre la salinidad en las bahías de destino. Pero la mayor parte del impacto se produce al observar de cerca sus vieiras. Las vieiras que mantienen sus cuidadores tienen más posibilidades de desovar con éxito cuando sea el momento adecuado.
Una jaula “Scallop Sitter” lista para ser colocada cerca de las praderas marinas. Las jaulas son herramientas de restauración utilizadas para producir crías de vieira durante el ciclo anual de crecimiento. Foto de L. Scott Jackson.
¿Qué hace un cuidador de vieiras? Los voluntarios dirigen jaulas de exclusión de depredadores de vieiras, que quedan colocadas en la bahía o junto a un muelle. Los “Scallop Sitters” (cuidador de vieiras) vigilan la tasa de mortalidad y recogen datos sobre la salinidad que ayudan a determinar los objetivos de restauración y el éxito en las zonas seleccionadas.
¡Está invitado! ¡Cómo convertirse un “Scallop Sitter” (cuidador de vieiras)!
Las fechas de entrenamiento para 2023 se anunciarán en breve. Por favor, envíenos un correo electrónico si está interesado en ser voluntario o en recibir información adicional. Chantille Gooding, Coordinadora de Recursos Costeros del Condado de la Bahía. c.gooding@ufl.edu
Una institución con igualdad de oportunidades. UF/IFAS Extension, Universidad de Florida, Instituto de Ciencias Alimentarias y Agrícolas, Andra Johnson, Decana de UF/IFAS Extension. Las copias individuales de las publicaciones de UF/IFAS Extension (excluyendo las publicaciones de 4-H y de los jóvenes) están disponibles gratuitamente para los residentes de Florida en las oficinas de UF/IFAS Extension del condado.
October has been designated as Coastal Dune Lake Appreciation month by Walton County government. Walton County is home to 15 named coastal dune lakes along 26 miles of coastline. These lakes are a unique geographical feature and are only found in a few places in the world including Madagascar, Australia, New Zealand, Oregon, and here in Walton County.
A coastal dune lake is defined as a shallow, irregularly shaped or elliptic depressions occurring in coastal communities that share an intermittent connection with the Gulf of Mexico through which freshwater and saltwater is exchanged. They are generally permanent water bodies, although water levels may fluctuate substantially. Typically identified as lentic water bodies without significant surface inflows or outflows, the water in a dune lake is largely derived from lateral ground water seepage through the surrounding well-drained coastal sands. Storms occasionally provide large inputs of salt water and salinities vary dramatically over the long term.
Our coastal dune lakes are even more unique because they share an intermittent connection with the Gulf of Mexico, referred to as an “outfall”, which aides in natural flood control allowing the lake water to pour into the Gulf as needed. The lake water is fed by streams, groundwater seepage, rain, and storm surge. Each individual lake’s outfall and chemistry is different. Water conditions between lakes can vary greatly, from completely fresh to significantly saline.
A variety of different plant and animal species can be found among the lakes. Both freshwater and saltwater species can exist in this unique habitat. Some of the plant species include: rushes (Juncus spp.), sedges (Cyperus spp.), marshpennywort (Hydrocotyleumbellata), cattails (Typha spp.), sawgrass (Cladiumjamaicense), waterlilies (Nymphaea spp.), watershield (Braseniaschreberi), royal fern (Osmundaregalis var. spectabilis), rosy camphorweed (Pluchea spp.), marshelder (Ivafrutescens), groundsel tree (Baccharishalimifolia), and black willow (Salixnigra).
Some of the animal species that can be found include: western mosquitofish (Gambusiaaffinis), sailfin molly (Poecilialatipinna), American alligator (Alligatormississippiensis), eastern mud turtle (Kinosternonsubrubrum), saltmarsh snake (Nerodiaclarkii ssp.), little blue heron (Egrettacaerulea), American coot (Fulicaamericana), and North American river otter (Lutracanadensis). Many marine species co-exist with freshwater species due to the change in salinity within the column of water.
The University of Florida/IFAS Extension faculty are reintroducing their acclaimed “Panhandle Outdoors LIVE!” series. Come celebrate Coastal Dune Lake Appreciation month as our team provides a guided walking tour of the nature trail surrounding Western Lake in Grayton Beach State Park. Join local County Extension Agents to learn more about our globally rare coastal dune lakes, their history, surrounding ecosystems, and local protections. Walk the nature trail through coastal habitats including maritime hammocks, coastal scrub, salt marsh wetlands, and coastal forest. A tour is available October 19th.
The tour is $10.00 (plus tax) and you can register on Eventbrite (see link below). Admission into the park is an additional $5.00 per vehicle, so carpooling is encouraged. We will meet at the beach pavilion (restroom facilities available) at 8:45 am with a lecture and tour start time of 9:00 am sharp. The nature trail is approximately one mile long, through some sandy dunes (can be challenging to walk in), on hard-packed trails, and sometimes soggy forests. Wear appropriate footwear and bring water. Hat, sunscreen, camera, binoculars are optional. Tour is approximately 2 hours. Tour may be cancelled in the event of bad weather.
Our coastal dune lakes are even more unique because they share an intermittent connection with the Gulf of Mexico, referred to as an “outfall”, which aides in natural flood control allowing the lake water to pour into the Gulf as needed. The lake water is fed by streams, groundwater seepage, rain, and storm surge. Each individual lake’s outfall and chemistry is different. Water conditions between lakes can vary greatly, from completely fresh to significantly saline.
