1 Rivers, lakes and springs Rivers, lakes and springs Florida: land of water Florida: land of water Inland and coastal Inland and coastal Flat topography, porous bedrock and Flat topography, porous bedrock and abundant rainfall create complex abundant rainfall create complex array of aquatic habitats array of aquatic habitats Biologically rich Biologically rich Apalachicola, Suwannee, St. Johns, Apalachicola, Suwannee, St. Johns, Myakka, Myakka, Oklawaha Oklawaha, Kissimmee, , Kissimmee, Loxahatchee, St. Loxahatchee, St. Marys Marys, Withlacoochee Withlacoochee More than 1700 rivers in Florida More than 1700 rivers in Florida Larger rivers: Larger rivers: blackwater blackwater and most and most discharge directly into sea discharge directly into sea Of 23 major rivers that discharge Of 23 major rivers that discharge into sea, 21 are located on the Gulf into sea, 21 are located on the Gulf coast. coast. Classification of Florida Classification of Florida’ s rivers and streams s rivers and streams • velocity of flow velocity of flow • substratum substratum • dissolved oxygen concentration dissolved oxygen concentration • water hardness (concentration of dissolved salts; mg/kg) water hardness (concentration of dissolved salts; mg/kg) Variation in these variables determine the Variation in these variables determine the suitability of a particular river or stream for various suitability of a particular river or stream for various organisms. organisms. Sand-bottomed steams: Sand-bottomed steams: most widely distributed most widely distributed moderate to swift flows moderate to swift flows slightly acidic (pH 5.7-7.4) slightly acidic (pH 5.7-7.4) shifting sand substrates shifting sand substrates Withlacoochee Withlacoochee, Hillsborough, Myakka, and , Hillsborough, Myakka, and Oklawaha Oklawaha rivers rivers
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Rivers, lakes and springsRivers, lakes and springs
array of aquatic habitatsarray of aquatic habitats
Biologically richBiologically rich
Apalachicola, Suwannee, St. Johns,Apalachicola, Suwannee, St. Johns,Myakka, Myakka, OklawahaOklawaha, Kissimmee,, Kissimmee,Loxahatchee, St. Loxahatchee, St. MarysMarys,,WithlacoocheeWithlacoochee
More than 1700 rivers in FloridaMore than 1700 rivers in Florida
Larger rivers: Larger rivers: blackwater blackwater and mostand mostdischarge directly into seadischarge directly into sea
Of 23 major rivers that dischargeOf 23 major rivers that dischargeinto sea, 21 are located on the Gulfinto sea, 21 are located on the Gulfcoast.coast.
Classification of FloridaClassification of Florida’’s rivers and streamss rivers and streams
•• water hardness (concentration of dissolved salts; mg/kg) water hardness (concentration of dissolved salts; mg/kg)
Variation in these variables determine theVariation in these variables determine thesuitability of a particular river or stream for varioussuitability of a particular river or stream for variousorganisms.organisms.
Porous limestone gradually dissolves inPorous limestone gradually dissolves incontact with water.contact with water.
Vast underground waterways formedVast underground waterways formedbeneath much of state.beneath much of state.
Lakes and ponds:Lakes and ponds:
Subsidence, collapse of underground cavitiesSubsidence, collapse of underground cavitiesresults in sinkholes or in shallow lakes.results in sinkholes or in shallow lakes.
Karst Karst topography: landscape marked bytopography: landscape marked bysinkholes and caves.sinkholes and caves.
Estimated 7,800 lakes in FloridaEstimated 7,800 lakes in Florida
Majority are small:Majority are small: only 5 with surface areas only 5 with surface areasgreater than 40 square milesgreater than 40 square miles
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Most are shallowMost are shallow:: average depth 15-20 feet average depth 15-20 feetLake Okeechobee: max. depth < 5 metersLake Okeechobee: max. depth < 5 meters
More than half of all the lakes occur in a 14-More than half of all the lakes occur in a 14-county area of central and north Florida.county area of central and north Florida.
FloridaFlorida’’s lakes: most are seepage lakes, nos lakes: most are seepage lakes, noinflow or outflow.inflow or outflow.
Hyper-eutrophicHyper-eutrophic: extremely well nourished.: extremely well nourished.
FloridaFloridaRainfall varies seasonally and annually. LakeRainfall varies seasonally and annually. Lakeevaporation fairly constant.evaporation fairly constant.
Result: dry years are frequent and rainfallResult: dry years are frequent and rainfalldeficiencies can be severe.deficiencies can be severe.
““NormalNormal”” years do not exist and some lakes years do not exist and some lakesfluctuate more than others, some lakes willfluctuate more than others, some lakes willdisappear.disappear.
FloridaFlorida’’s lakes and waterways: impacted bys lakes and waterways: impacted byexotic water plants.exotic water plants.
Water hyacinth (Water hyacinth (Eichhornia crassipesEichhornia crassipes))
Support diverse flora and faunaSupport diverse flora and fauna
Bathing, boating, skiing, fishing,Bathing, boating, skiing, fishing,irrigation and drinking.irrigation and drinking.
Growing human population. Water useGrowing human population. Water useand water quality will become majorand water quality will become majorissues.issues.
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Florida:Florida:Over 300 named springs in north andOver 300 named springs in north andcentral regions.central regions.
Springs are artesian.Springs are artesian.
Some holes open into caverns.Some holes open into caverns.
Significant differences in physical andSignificant differences in physical andchemical features of springs.chemical features of springs.
Largest springs are Largest springs are ““first-magnitudefirst-magnitudespringssprings””
Flow rates of > 3 million gallons of waterFlow rates of > 3 million gallons of waterper hour.per hour.
During cold spells water is warmer than theDuring cold spells water is warmer than thefreezing air temperature: springs attract largefreezing air temperature: springs attract largenumbers of manatees.numbers of manatees.
Belted kingfisher: Perch hunts, divesBelted kingfisher: Perch hunts, divesheadfirst for small fish, hover-like flight,headfirst for small fish, hover-like flight,distinctive rattle calldistinctive rattle call
Hole nestersHole nesters
Southern bald eagleSouthern bald eagle
Estimated 500 pairs inEstimated 500 pairs inUS in early 1960sUS in early 1960s
Banning of DDT in 1972Banning of DDT in 1972halted decline: 10-foldhalted decline: 10-foldincrease in USincrease in US
Florida has played an important roleFlorida has played an important rolein recovery.in recovery.
Florida has largest bald eagleFlorida has largest bald eaglepopulation in lower 48 states.population in lower 48 states.
Florida: number of active nestsFlorida: number of active nests
Habitat: Habitat: suitable nest and perch sites in suitable nest and perch sites in proximity to large, open proximity to large, open waterbodieswaterbodies
•• Collisions with vehicles, power linesCollisions with vehicles, power lines
•• Bioaccumulation of contaminantsBioaccumulation of contaminants
•• Disturbance in early stages of breedingDisturbance in early stages of breeding
•• Nest abandonmentNest abandonment
•• High levels of boat activity may limitHigh levels of boat activity may limitforaging areasforaging areas
OspreyOsprey
Occur in Florida bothOccur in Florida bothas nesting species andas nesting species andmigrantsmigrants
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Major nesting areas in Florida:Major nesting areas in Florida:
Nest along Gulf Coast from ApalachicolaNest along Gulf Coast from ApalachicolaRiver to Keys;River to Keys;
Atlantic coast from St. MaryAtlantic coast from St. Mary’’s River tos River toMerritt Island;Merritt Island;
and St. Johnand St. John’’s and Kissimmee rivers.s and Kissimmee rivers.
Nests constructed in tops of large living andNests constructed in tops of large living anddead trees. Will also use man-madedead trees. Will also use man-madestructures: utility poles, radio towers, channelstructures: utility poles, radio towers, channelmarkers.markers.
Elaborate courtship flights in air over nestElaborate courtship flights in air over nestsites.sites.
Male will bring fish to its mate.Male will bring fish to its mate.
Clutch size: 3Clutch size: 3
Fledge: 55 days, continue to be fed until 90-Fledge: 55 days, continue to be fed until 90-100 days100 days
50-60% of all active nests fledge 1 or > 50-60% of all active nests fledge 1 or > ygyg
Diet:Diet:
Prey 7-16 inches long (catfish, crappie,Prey 7-16 inches long (catfish, crappie,sunfish, mullet, shad)sunfish, mullet, shad)
Capture by diving into water with talonsCapture by diving into water with talonsextended.extended.
Will orient prey in talons, align with bodyWill orient prey in talons, align with bodyof bird when carrying prey back to perch.of bird when carrying prey back to perch.
Conservation:Conservation:
Estimate of 1,500 - 2,000 pairs in FloridaEstimate of 1,500 - 2,000 pairs in Florida
Small rounded ears. Ears and nostrils closeSmall rounded ears. Ears and nostrils closeunder water. 5-14 kg. Amphibious.under water. 5-14 kg. Amphibious.
Habitat: almost every aquatic habitat inHabitat: almost every aquatic habitat inFlorida except the KeysFlorida except the KeysDens: bank burrows, under roots of tree, rockDens: bank burrows, under roots of tree, rockpiles; both permanent and temporary nestspiles; both permanent and temporary nests
Den has underwater entrance with tunnel toDen has underwater entrance with tunnel tonest chambernest chamber
•• Breed once/yr: late summer or fall in FLBreed once/yr: late summer or fall in FL
•• Delayed implantation: gestation may last aDelayed implantation: gestation may last ayear, with 2 month pregnancyyear, with 2 month pregnancy
•• Litter size: 1-6, but 2-3 Litter size: 1-6, but 2-3 yg yg commoncommon
•• Post-partum estrusPost-partum estrus
•• Young fully furred, but helpless, at birthYoung fully furred, but helpless, at birth
•• Depend on mother for about 1 yearDepend on mother for about 1 year
Otters: unusually high metabolic rateOtters: unusually high metabolic rate
Water rapidly conducts heat away from bodyWater rapidly conducts heat away from body
Creates high-energy demands: depending onCreates high-energy demands: depending onwater temperature, individual may need towater temperature, individual may need toeat 15% of body weight/day in fisheat 15% of body weight/day in fish
Vulnerable to changes in prey availabilityVulnerable to changes in prey availability
Females with young: 8 hours/nightFemales with young: 8 hours/nighthuntinghunting
Diet of fish, crayfish, frogs, crabs,Diet of fish, crayfish, frogs, crabs,turtles, bird eggs, snakes, smallturtles, bird eggs, snakes, smallmammalsmammals
Otters: social animalsOtters: social animals
Vocal repertoire is large (chirps, whistles)Vocal repertoire is large (chirps, whistles)
Densities in good habitat: 1 otter per 3-5Densities in good habitat: 1 otter per 3-5mile of waterwaymile of waterway
MustelidaeMustelidae: strong musk glands in anal: strong musk glands in analregion. Common scent mark: fecesregion. Common scent mark: feces((spraintspraint) left at conspicuous points along) left at conspicuous points alongriver bank.river bank.
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Fur is valuable: harvestedFur is valuable: harvested
Status in Florida is not well knownStatus in Florida is not well known
Vulnerability: loss of wetland habitatsVulnerability: loss of wetland habitats
DonDon’’t cope well with vehicles: t cope well with vehicles: roadkillsroadkills