Ecological Risks in the Ecological Risks in the Caloosahatchee Estuary: Caloosahatchee Estuary:

A Conceptual Model Developed A Conceptual Model Developed through the Southwest Florida through the Southwest Florida

Feasibility Study Feasibility Study

Darren Rumbold, Ph. DDarren Rumbold, Ph. DProfessor of Marine ScienceProfessor of Marine Science

Depart. of Marine and Ecological SciencesDepart. of Marine and Ecological SciencesCoastal Watershed InstituteCoastal Watershed Institute

Florida Gulf Coast UniversityFlorida Gulf Coast University

Southwest Florida Feasibility Study (SWFFS)Southwest Florida Feasibility Study (SWFFS) Purpose and Relationship to Comprehensive Purpose and Relationship to Comprehensive Everglades Restoration Plan (CERP) and Critical Everglades Restoration Plan (CERP) and Critical ProjectsProjects The Restudy recommended a

separate Comprehensive watershed study for Southwest Florida with the following purposes

• Health of aquatic ecosystems

• Water flows

• Water quality (including appropriate pollution reduction targets)

• Water supply (Lower West Coast Water Supply Plan)

• Flood damage reduction

• Wildlife and biological diversity

• Natural habitat

• Recreation (opportunity)

Barnes, 2005

Benefits of Developing Conceptual Models?Benefits of Developing Conceptual Models?

• The process of creating a conceptual model is a powerful learning tool.

• Conceptual models are easily modified as knowledge increases.

• Conceptual models highlight what is known and not known and can be used to plan future work.

• Conceptual models can be a powerful communication tool. They provide an explicit expression of the assumptions and understanding of a system for others to evaluate.

• Conceptual models provide a framework for prediction and are the template for generating more risk hypotheses.

Barnes, 2005

StressorsStressors

• Sea Level RiseSea Level Rise• Water Management Water Management • Land Use & Land Use &

Management Management • Maintaining NavigationMaintaining Navigation

• Altered Estuarine Altered Estuarine SalinitySalinity

• Altered HydrologyAltered Hydrology• Input & Elevated Levels Input & Elevated Levels

of Nutrients, Dissolved of Nutrients, Dissolved Organics & ToxinsOrganics & Toxins

• Boating & Fishing Boating & Fishing PressurePressure

• Physical Alteration to Physical Alteration to EstuaryEstuary

DriversDrivers

Altered Salinity RegimeAltered Salinity Regime

• While estuarine species are generally well adapted to cope with varying salinity conditions, larger shifts and timing of freshwater discharges can be a problem.

– impacts the community structure and function of phytoplankton, submerged aquatic vegetation (SAV), macroalgae, benthos- particularly oysters and fisheries

• Secondary, or indirect, effects on manatee demographics and wading bird community structure

Important to Clearly Identify and Important to Clearly Identify and Communicate Cascading Adverse EffectsCommunicate Cascading Adverse Effects

• Primary, or direct, effects: Primary, or direct, effects: – occur when a stressor acts directly on the occur when a stressor acts directly on the

assessment endpoint and causes an adverse assessment endpoint and causes an adverse response response

• Secondary, or indirect, effects: Secondary, or indirect, effects: – occur when the entity’s response becomes a occur when the entity’s response becomes a

stressor to another entitystressor to another entity– are often a series of effects among a diversity of are often a series of effects among a diversity of

organisms and processes that cascade through organisms and processes that cascade through the ecosystemthe ecosystem

– may have greater ecological significance than may have greater ecological significance than primary effectprimary effect

Increased Nutrients & Increased Nutrients & ContaminantsContaminants

• Biostimulants, e.g., inorganic and Biostimulants, e.g., inorganic and organic nutrients, influence growth and organic nutrients, influence growth and community structure of phytoplankton, community structure of phytoplankton, macroalgae, and microbes.macroalgae, and microbes.

– Indirect effects on SAV, zooplankton, fish Indirect effects on SAV, zooplankton, fish and other aquatic organisms from: 1) light and other aquatic organisms from: 1) light attenuation, 2) altered dissolved oxygen attenuation, 2) altered dissolved oxygen concentrations, and 3) biotoxins concentrations, and 3) biotoxins

• which, in turn, can have cascading effects on which, in turn, can have cascading effects on manatee, dolphins and wading bird community manatee, dolphins and wading bird community structurestructure

Cloern 2001, Marine Ecology Progress Series

Table 1. Summary of findings of water quality assessments in the Caloosahatchee Estuary, San Carlos Bay, Pine Island Sound and Matlacha Pass.

Waterbody Doering and

Chamberlain, 1998a

Janicki Environ. Inc.,

2002b

FDEP, 2002; 2003c

ERD, 2003d Janicki Environ

Inc., 2003e Tetra Tech, Inc., 2004f

Upper Caloosahatchee (WBID 3240C)

Chl a>11 ug/L TP>state median TN>state median DO<WQS Color rel. high

Chl a>ref. site, IWR TN>ref. site TP>historic, ref. site DO<historic, ref. site, IWR Turbidity>historic

Impaired for: Chl a, DO, coliform

Strong gradient with decreasing conc. of most constituents with increasing dist. from S79; Chl a>11 ug/L DO<WQS

Unaccept. based on informal IWR: Chl a, DO, coliform; trend of declining WQ in BOD, TSS, nutrients, secchi depth

Decreasing trends in DO, increasing trends in turbidity, potassium and TN; Improvements in TP; Water of Concern: Fecal Coliform, DO, unionized ammonia (tribs), nutrients, iron, copper, conductance (tribs)

Middle Caloosahatchee (WBID 3240B)

Chl a>11 ug/L TN > state median

Chl a>ref. site, IWR TN>ref. site TP>ref. site DO<ref. site, IWR Turbidity>ref. site

Impaired for: Chl a, DO, copper, coliform

Spike in downstream gradient in ammonia, TKN, TN and Chl a. Chl a>11 ug/L

Unaccept. based on informal IWR: Chl a, DO, coliform; trend of declining WQ in BOD, TSS, nutrients, secchi depth

Decreasing trends in DO, increasing trends in turbidity, BOD, TSS; mixed trends in TP; Water of Concern: Fecal Coliform, DO, unionized ammonia (tribs), nutrients, iron, copper

Lower Caloosahatchee (WBID 3240A)

TN>state median

Chl a>ref. site, IWR TN>ref. site TP>historic, ref. site DO<historic, ref. site, IWR Turbidity>historic

Impaired for: Chl a, DO, copper, lead, biology

Mean DO>WQS

Unaccept. based on informal IWR: Chl a, DO, coliform; trend of declining WQ in BOD, TSS, nutrients, secchi depth

Decreasing trends in DO, increasing trends in turbidity, TSS, nitrite+nitrate, BOD, TP, and fecal coliform; mixed trends with TNand TKN, Water of Concern: Fecal Coliform, DO, nutrients, iron, copper, conductance (tribs)

Table 1. Continued.

Waterbody Doering and

Chamberlain, 1998a

Janicki Environ.

Inc., 2002b

FDEP, 2002; 2003c

ERD, 2003d

Janicki Environ Inc.,

2003e

Tetra Tech, Inc., 2004f

San Carlos Bay (WBID 2065H)

Chl a rel. low TN>state median DO rel. high Turbidity rel. low; TSS > state median

not assessed

No listed impairment

Chl a<11 ug/L Mean DO>WQS

Assessed under Matlacha Pass

DO, turbidity trends not assessed;

Pine Island Sound (WBID 2065E and G)

Chl a rel. low TN>statewide median DO rel. high TSS>state median

not assessed

Impaired for: bacteria (in shellfish)

not assessed

Accept. based on informal IWR; exceedances in ammonia and DO at some stations

Decreasing trends in DO; Water of Concern: Fecal Coliform, DO (Sanibel), nutrients (St James City)

Matlacha Pass (WBID 2065F)

Chl a rel. low TN>state median DO rel. high

not assessed

No listed impairment

not assessed

Accept. based on informal IWR; improving trends in secchi depth and TN

Decreasing trends in DO, increasing trends in turbidity Water of Concern: Fecal Coliform, DO (Gator Slough)

SW coast not assessed not assessed

Mercury not assessed

Water of Concern: nutrients

Increased Nutrients & Increased Nutrients & ContaminantsContaminants

• Toxicants, both metals and organics (e.g., Toxicants, both metals and organics (e.g., pesticides, pharmaceuticals and personal pesticides, pharmaceuticals and personal care products) could be having insidious care products) could be having insidious effects on individuals (e.g., effects on individuals (e.g., immunosuppression, behavior, etc.) immunosuppression, behavior, etc.) populations and community structure.populations and community structure.

– Loss or contamination of prey can have Loss or contamination of prey can have indirect effects on fish and wildlife indirect effects on fish and wildlife predators (e.g., sharks, dolphins, birds), as predators (e.g., sharks, dolphins, birds), as well as human consumerswell as human consumers

WQ PERFORMANCE MEASURE

Loading model

Process model,e.g., ECOlab

BMP effectiveness as % reduction

Parameter;causal, response or both

HSI model; BPJEco-resource,

e.g., SAV, oysters, redfish; sawgrass

Reference site, e.g., 10K Island,

25th - 75th percentilefor a given salinity regime

Historical-based,e.g., natural systems, OFW, etc.

WQS; Inflow v. outflow

Target

Habitat Units, e.g., acres, lbs,

Catch per unit effort

TSS; TurbidityDOC / DOM;

TN (NOx + TKN); TP, SRP

Empirical model, e.g., regression

Empirical model, e.g., regression

Process model,

e.g., ECOlab

Input parameters will include: Land use

SoilsTopography

Land use-specific event mean conc.Land use-sp. runoff coefficient

Many other simplifying assump.

Input parameters might include: water-column BOD, COD; sediment oxygen demand;

adsorption coeff., particle-size distribution, settling coeff.;rates of nitrification, denitrification, mineralization and fixation;

reaeration rate (SA/vol., temp., turbulence, stratification, algal growth, photosynthesis, respiration, settling rates;

light avail. (note, inter-dependence).

Output Scale ??? Instantaneous minimum ---Seasonal means

Point - River segment - Spatially explicit

Constraint

Dissolved Oxygen; Chl-a;

Color; Clarity / PAR

concentration

concentration

loads

NEED TO CONNECT THE DOTs

Basine.g., C43,

Tidal Caloosahatchee, Estero, and BCB

Componentspecific

loads

loads

Fraction of Freshwater

Method, i.e., mass balance

conc

entr

atio

n

BPJ

Coordinate w/ Natural Systems Group

Cloern 2001, Marine Ecology Progress Series

Simultaneous Effects of Multiple Stressors

“The presence of multiple stressors may either increase or dampen the temporal and spatial variability seen in aquatic systems, depending on the interactions among stressors and the influence of background environmental conditions and sensitive species on the expression of stressor effects.” (Breitburg et al. 1999)

Breitburg et al. 1999

Barnes, 2005

Take Home MessageTake Home Message

• Many people invested an incredible amount Many people invested an incredible amount of time and energy in the SWFFS developing of time and energy in the SWFFS developing decision-support products such as the decision-support products such as the conceptual model conceptual model

• Although those products should serve Although those products should serve as a as a strong foundation, they can be improved strong foundation, they can be improved upon and expanded, especially theupon and expanded, especially the predictive predictive models linking stressors with eco-resources models linking stressors with eco-resources

• We are not under the same constraints as We are not under the same constraints as SWFFS and so can develop an analysis plan SWFFS and so can develop an analysis plan for research to fill data gaps, particularly on for research to fill data gaps, particularly on simultaneous effects of multiple stressors simultaneous effects of multiple stressors and indirect effectsand indirect effects