Impacts of Sea Level Rise:

• Loss of freshwater coastal dune lakes as salt water encroaches into system
• Loss of coastal freshwater marshes – conversion to brackish/salt marsh
• Reduction/loss of critical freshwater sources in the Keys

Impacts of Salinity Shifts:

• Decrease in salt-intolerant vegetation due to increased salinity
• Decrease in coastal and tidal freshwater marshes due to changes in community structure as salinity increases
• Loss of critical freshwater sources in the Keys due to salt water intrusion
• Decreased productivity/growth of vegetation (wild celery)
• Reduction in groundwater due to changes in location/amount of withdrawals for drinking water as salinity increases at some locations
• Loss of suitable habitat for those species with limited osmoregulation

Impacts of Warmer Summer Temperatures:

• Reduction or loss of wetland habitats due to increased evaporation rates
• Higher eutrophication rates
• Reduction of submerged aquatic vegetation
• Increased growth rates of aquatic vegetation
• Increase in invasive species that can tolerate higher temperatures and low oxygen
• Increased algal blooms
• Less dissolved oxygen in the system

Impacts of Warmer Winter Temperatures:

• Northward range shift of aquatic exotic species
• Increased growth rate and expansion of invasive plant species

Impacts of Increased Extreme Heat Events:

• Reduction or loss of wetland habitats due to increased evaporation rates
• Higher eutrophication rates
• Increase in invasive species that can tolerate higher temperatures and low oxygen
• Increased algal blooms
• Less dissolved oxygen in the system
• Northward range shift of aquatic exotic species
• Increased growth rate and expansion of invasive plant species

Impacts of Increased Extreme Cold Events:

• Increased mortality for cold temperature sensitive species
• Increased occurrence and severity of cold kill events
• Limit northern extent of exotic species range (potentially beneficial change)

Impacts of Increased Precipitation:

• Increased nutrient and sediment loading due to increased runoff
• Reduction in availability/connectivity of spawning areas

Impacts of Decreased Precipitation:

• Reduced average freshwater discharge from Lake Okeechobee
• Reduced littoral zone flushing of tussock and other organic material
• Reduced spawning habitat as connectivity between rivers and floodplain is reduced
• Increased abundance, prevalence and diversity of aquatic parasites
• Increased cyanobacteria blooms and cyanotoxin concentrations in waterbodies
• Decreased connectivity of 1st and 2nd order streams to main channel
• Reduced river stage and flows in panhandle affecting freshwater mussel beds
• Loss of herbaceous aquatic vegetation as hardwood and pine encroaches into wetlands
• Lake bottom drying allows for burning of land bed stimulates desirable aquatic plants (potentially beneficial change)

Impacts of Changes in Timing of Precipitation:

• Altered water chemistry
• Altered low level trophic interactions – temporal mismatch between phytoplankton and zooplankton
• Reduced connectivity during breeding season

Impacts of Changes in Frequency and Severity of Extreme Events:

• Altered habitat type/composition of wetland communities due to wind damage
• Increased erosion, sediment transport and runoff into freshwater systems
• Increased spread of exotic or invasive species
• Increased levels of particulate and dissolved substances (nitrates, ammonia)
• Altered water chemistry due to increased runoff
• Increased mortality due to increased pollution entering the aquatic systems
• Increased stream flow
• Increased high water levels due to increased precipitation from storms
• Altered water quality due to changes in nutrient and sediment
• Increased extent of freshwater habitats due to increased precipitation from storms (potentially beneficial change)

Impacts from Increased Floods:

• Increased connectivity of ephemeral wetlands to adjacent wetlands and water bodies
• Increased woody debris carried in stream channels
• Increased flow of pollutants from surrounding watersheds into streams, rivers, ponds and lakes
• Displacement of stored organic carbon as floods cause scouring of the streambed
• Increased turbidity and sedimentation from runoff

Impacts from Increased Droughts:

• Changes in stream temperature
• Changes in debris loads due to alterations in riparian vegetation
• Decreases in the oxygen-holding capacity of surface water
• Increased anoxia and chemical transformation in surface waters
• Alterations in the transport of organic matter or sediments into freshwater systems
• Increased heavy metals and other toxic substance concentrations Decreased bacterial, fungal and microbial activity due to reduced detritus decomposition
• Increased protozoa and bacteria levels in warm water
• Increased habitat fragmentation due to changes in spatial distribution and extent of habitat
• Increased invasive nonnative plant species in lakes and wetlands
• Reduced spring flow
• Increased mortality of riparian trees and other vegetation
• Loss of connectivity between freshwater systems
• Decreased stream flow or drying up of streams in areas downstream of springs

Impacts of Altered Water Chemistry:

• Increased invasive plant growth for those species that have an affinity for CO2 (e.g., hydrilla)
• Increased damage to host plants by epiphytes due to increased epiphytic growth
• Increased harmful algal blooms due to high nutrient inputs
• Altered community composition – loss of more sensitive species
• Reduced fitness for shell producing species
• Altered growth rates
• Increased eutrophication

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What's next?

Learn about impacts and adaptation strategies for conservation assets and habitats in freshwater ecosystems.

Learn about climate-related impacts to marine and estuarine ecosystems in Florida.