340 likes | 467 Views
Apalachicola River, Floodplain and Bay. Largest forested floodplain in Florida (112,000 acres) Highest Species Diversity of any River System in North America UNESCO Biosphere Reserve Outstanding Florida Water (OFW). Habitat Diversity
E N D
Apalachicola River, Floodplain and Bay Largest forested floodplain in Florida (112,000 acres) Highest Species Diversity of any River System in North America UNESCO Biosphere Reserve Outstanding Florida Water (OFW)
Habitat Diversity Apalachicola River Floodplain hosts the highest biodiversity of any River System in North America 50 species of mammals 1300 species of plants 40 species of amphibians80 species of reptiles 300 species of birds See Apalachicola National Estuarine Research Reserve info
ProductivityHarvest $200 million Local Seafood Industry, 90% of Florida Oysters, and 10% of US oysters, plus shrimp, crab and finfish. In 1994, Five Million lbs. of Seafood were produced from the Apalachicola Bay region. 90% of all harvested species must spend some part of their life cycle inshore on the marsh and seagrass environment, even the grouper caught offshore must rely on this healthy environment.
Natural Features of river and floodplain Swamp Cut bank Main channel Slough Point Bar used for Disposal Site Levee
Forest Types Distributed by Elevation Upland High Bottomland Hardwoods Low Bottomland Hardwoods Swamps Floodplain slough Main channel
River Level Controls Water in Floodplain Upland High Bottomland Hardwoods Low Bottomland Hardwoods Swamps Floodplain slough Main channel
River Level Controls Water in Floodplain Upland High Bottomland Hardwoods Low Bottomland Hardwoods Swamps Floodplain slough Main channel
River Level Controls Water in Floodplain Upland High Bottomland Hardwoods Low Bottomland Hardwoods Swamps Floodplain slough Main channel
River Level Controls Water in Floodplain Upland High Bottomland Hardwoods Low Bottomland Hardwoods Swamps Floodplain slough Main channel
High and Low Water Seasons(before 1954) Upland High Bottomland Hardwoods Low Bottomland Hardwoods Swamps Early Spring Summer Fall Floodplain slough Severe drought Main channel
2007 Flow in relation to Average Flow Apalachicola River at Chattahoochee, FL Average flow 1922-2007 2007 flow
Stagnant conditions develop if sloughs are isolated for long periods
Fish trapped in floodplain will die if water dries up in isolated pools
Crawfish Integral Part of Food Chain In the Apalachicola River System, crawfish are an integral part of the food chain and are an important food source of terrestrial and aquatic species. .
Crawfish Integral Part of Food Chain • From the time Crawfish emerge from the ground, they are a major food source for fish, eels, turtles, otter, frogs, snakes, beaver, possum, young alligator, birds, and raccoons. • High water is the time when aquatic species migrate into the flood plain to spawn and forage.
Crawfish Lifecycle • During the seasonal low water when the floodplain is not inundated, crawfish remain burrowed underground. • Crawfish start emerging at the beginning of the seasonal high water typically between December & February, depending on flow regime. • Upon emergence, crawfish have lost weight and immediately begin to forage for food. • A crawfish's favorite food is soft, decomposing plant matter; however, they will eat just about anything – algae, snails, insects, plants, dead fish, etc. Crawfish are cannibals and will even consume other crawfish that are molting.
Crawfish Lifecycle • After foraging above ground to regain weight, crawfish begin to spawn. • In the mating process, males place a sperm packet on the underside of the female's belly. Male top; female bottom
Crawfish Lifecycle • After the sperm packet is placed on the underside of the female crawfish, she curls up her tail and expresses the eggs. • She passes the eggs through the sperm down on to her tail and attaches them to the swimmerets, feathery apertures on the underside of the back section of her body.
Crawfish Lifecycle • Eggs stay on the tail for at least four weeks. Variables such as food and water conditions can effect this gestation period. • When hatched, the young remain attached to the mother until maturity. • At the end of two weeks the young are capable of surviving on their own, at which time the mother flips her tail, releasing them into the water column.
Crawfish Lifecycle, continued • After being released into water columns by the mothers, babies settle to the bottom and begin to forage and grow. • In 6-8 weeks they are large enough to catch in baskets.
Crawfish Lifecycle Disruptions • Crawfish are unable to complete their growing cycle when only a short period of floodplain inundation occurs. • From 2002-2008, there was only 4-6 weeks of floodplain inundation, causing disruption in the crawfish lifecycle.
Crawfish Lifecycle Disruptions • Rapid drops in water level below 8.5’ at the Blountstown gauge also disrupt the lifecycle. • It does not allow enough time for Crawfish to burrow into the ground, leaving them exposed to predators and interrupts the lifecycle. • When the water level drops below 8.5’, the Crawfish start burrowing down, and are burrowed in the ground at around 6’ water level.
Crawfish Lifecycle Disruptions • Crawfish are unable to complete their growing cycle when only a short period of floodplain inundation occurs. • From 2002-2008, there was only 4-6 weeks of floodplain inundation, causing disruption in the crawfish lifecycle.
Summary of Major Impacts: DECLINING RIVER STAGE Reduced flow Woody debris removal Loss of Fish Habitat and Fish Reduction of aquatic species DRYING OUT OF FLOODPLAIN FOREST Decrease in Forests Density Loss of 4 million trees Disconnected Sloughs DECLINING SEAFOOD HARVEST River flow drives the Bay and Eastern Gulf Loss of Nutrients and Organics Increased Salinity, Temperature and Disease Chain reaction thru Food Chain
Summary of Major Impacts: • http://water.weather.gov/ahps2/hydrograph.php?wfo=tae&gage=blof1&view=1,1,1,1,1,1,1,1
The Apalachicola River System The Apalachicola River System consists of the river and a 112,000 acre floodplain that ranges from 1-3 miles wide and discharges to the Bay.
Flow ComparisonApalachicola River at Chattahoochee, Florida Pre-Dam Post-Dam 1923-1955 33-yr period before filling of Lanier 1975-2007 33-yr period after filling of West Point
Pre-Dam FlowsFor Groups of Years Ranked by Average Annual Flow
Pre-Dam FlowsFor Groups of Years Ranked by Average Annual Flow
Pre-Dam Vs Post-Dam Annual Rainfall Unchanged 10% LESS annual flow (30% LESS Apr-Aug flow)
Pre-Dam Vs Post-Dam Annual Rainfall Unchanged 18% LESS annual flow (38% LESS Apr-Aug flow)