Ecological Assessment and Management Planfor the Humacao Wildlife Refuge, Puerto Rico

Matthew J. Gray and Francisco J. Vilella

Mississippi Cooperative Fish and Wildlife Research UnitProject FW-10

Geographic Location ofHumacao Wildlife Refuge

Puerto Rico

San Juan

HumacaoMiami, FL

San Juan, PR

1000 miles

N

Creation of Humacao Wildlife Refuge

Caribbean Sea

Route #925 Route #3

Caribbean SeaCaribbean

Sea

Port

Pre-Hurricane Post-Hurricane

August 1979

Sugar Cane Farming

Coconut Palm Plantations

Effects of Hurricane David and Tropical Storm Frederick (Humacao Wildlife Refuge)

Pre-Hurricane Post-Hurricane

Acquisition and Boundaries of Humacao Wildlife Refuge

Property Delineations

Caribbean Sea Caribbean

Sea

Management JurisdictionDNER

PR LandAuthority

PR LandAdminstration DNER

1100 ha

Conservation Trust

Habitat Types atHumacao Wildlife Refuge

Estuarine LagoonsBeach Scrub Coastal Forest

Herbaceous Wetlands

Forested Wetlands

Mangrove Pterocarpus

DNER Objectives and Research at Humacao Wildlife Refuge

Designated as a Natural Reserve in 1984 (Waterfowl Management Emphasis)

CurrentInitial

Preservation

Descriptive Research

Applied Wetland Management

Quantitative Research

Mississippi Cooperative Fish andWildlife Research Unit Objectives

1. Quantify current abiotic and biotic conditions atHumacao Wildlife Refuge

2. Develop a management plan to maximizewetland productivity and waterbird use.

3. Train local biologists in wetland management.

Ecological Assessment

Wetland Management Plan

2 Training Workshops

Ecological Assessment

Habitat Categories Investigated during Ecological Assessment

Aquatic Herbaceous Forested Mandri 1 Mandri Beach Scrub Mandri 2 Santa Teresa Coastal Forest Mandri 3 MangroveSanta Teresa 1 PterocarpusSanta Teresa 2 Palmas

Parameters Measured in Aquatic Habitats

Water:

Communities:

Dissolved oxygen, salinity, transparency,temperature, and depth.

Abundance and diversity of Fish and Birds.

Water Sampling

10 Random Locations/Lagoon/MonthChemistry: ! Pre-sunrise (0400-0700 hrs)

! Surface and Bottom Sampled/Location

! Mid-afternoon (1400-1700 hrs) on Cloudless Days! Water Depth Measured Concurrently

Transparency:

Secchi Disk

YSIMeters

Fish Sampling1 Fixed Location/Lagoon/Month

! Sampling Time (0800 & 1000 hrs) ! Set Time = 1 Hour! Capture Fish Identified, Measured, Weighed! Dead Fish Donated to Local Fisherman

80-m Graduated Gill Net

DNER Personnel

Bird Sampling

Vegetation/WaterInterface

Edge Zone

(2 m Width)

Open-WaterZone

InteriorZone

Direction ofKayak Travel

150-m

Variable-Distance Segmented Line Transects! Line = Vegetation/Water Edge ! Segment = 150-m Distance along Line! Replication = Segments Sampled Alternately/Month (n > 6/lagoon)! Species and Approximate Perpendicular Distance Recorded! Micro-habitat Categories (Edge, Open Water, Interior Wetland)

Parameters Measured in Herbaceous Habitats

Vegetation:

Communities:

Plant height and diversity, seed yield, litterdepth, and percent composition of grasses,forbs, vines, litter, and bareground.

Abundance and diversity of Insects, Birds,and Rodents.

Sampling in Herbaceous Habitats

Vegetation 1-m2 Randomly Located Plots

Insects 9-in2 Flourescent Pans Systematically Placed

VertebratesVictor® Rat & Mouse Traps Systematically Placed 35 Trap Nights

Bird Sampling in Herbaceous and Forested Habitats

10-25 m 25-50 m >50 m50m

Parameters Measured in Forested Habitats

Vegetation:

Communities:

Plant density, diversity, and height, DBH, percentcomposition of grasses, forbs, vines, woody stems,litter, and bareground, and visual obscurity, andpercent canopy cover.

Abundance and diversity of Insects, Birds,and Terrestrial Vertebrates.

1-m2 10-m2 100-m2

Sampling Stations in Terrestrial Habitats

Caribbean Sea

Caribbean Sea

84o

Purple = Beach Scrub Brown = Pterocarpus

Gray = Coastal Forest Red = Mangrove

Vegetation Measuring in Forested Sites

ClinometerDensiometer

DBH Tape

Modified Nudds (1977) Board

Ancillary Sampling

! Night (2000 - 0200 hrs) and Morning (0600 - 0800 hrs) ! Turtle Visits (i.e., tracks) Recorded! Encountered Turtles were Tagged, Morphological

Measurements Taken, and Clutch Size Recorded

Sea Turtle Patrols:

! Weekly Searches in Kayaks ! Confined to Nesting Platforms and

Vegetation/Water Edge ! Clutch Size and Species Recorded

Waterfowl Nest Searches:

! Precipitation Receptacle! Measured Daily at 0700 hours

Rainfall:

Statistical Analysis

Vegetation, Water, and Animal Community Data:

Percent Coverage of Vegetative Life Forms:

Capture Frequency of Vertebrates:

A) ParametricRepeated measures, Multivariate, and Univariate ANOVA’s, 2-Sampleand Paired t-tests, and Least-squares means multiple comparison test

B) Non-parametricKruskal-wallis, Cox-Cochron, and Wilcoxon Rank-Sum tests

216 Analyses Conducted

Logit Categorical Data Analysis

Compositional Data Analysis Xi = ln%i

(%1 * %2 * . . . * %D)1D

lnJ0*ij

J1*ij= " + $i B + $i T

Generalized Results in Aquatic Habitats

Water! Salinity and Depth were GREATEST in

Mandri 1 and LEAST in Santa Teresa 2Distance from Sea

! Transparency typically GREATER in SantaTeresa than in Mandri lagoons.

Turbidity and Phytoplankton

! Dissolved Oxygen was GREATEST in Mandrilagoons during April, but Oxygen in Mandriwas SIMILAR or LOWER than Santa Teresalagoons during June.

Rainfall, Phytoplankton, and Temperature

Generalized Results in Aquatic Habitats

Birds and Fish! Bird Abundance and Diversity were GREATEST in Mandri 1

Landscape Heterogeneity! Bird Abundance in Edge and Interior Zones was GREATEST

in Mandri 1.

Micro-habitat Characteristics and Diversity

! GREATEST Abundance of Brown Pelicans was in Mandri 3

Fish Diversity and Water Depth

! Bird Abundance in the Open Water Zone was GREATEST inMandri 2.

Fish Abundance and Poor Adjacent Habitat

Generalized Results in Herbaceous Habitats

! Insect Abundance was GREATEST in Mandri wetlandsMean plant diversity and height, percentlitter and depth were Greater in Mandri

! Seed yield was GREATER in Santa Teresa than inMandri wetlands

Occurrence of Paspalum vaginatum wasgreater in Santa Teresa than in Mandri

Typically, NO Differences (P > 0.05) Detected

Duck-use-days Calculations

Mandri 292 kcalday2500kcal kg

150 kgha138 ha 178K

Santa Teresa 73 ha 600

kgha

2500kcal kg 292kcalday 377K

SeedYieldWetland Area MTE DER DUD

½ MillionDuck-use-Days

6 Months

Oct -March

3083Ducks/Day

Generalized Results in Forested Areas

! Bird Abundance and Diversity and Vertebrate Species Richnesswere GREATEST in Mangrove

Landscape Heterogeneity, Ecotones,and Micro-habitat Complexity

! Insect Species Diversity was GREATEST in Pterocarpus

Forest-Age Hypothesis, Resource Partitioning,Niche Diversification

! Vertebrate and Insect Abundance was GREATEST inCoastal Forest

Forest-Age Hypothesis, Generalists, HighReproductive Rates Years10 20 40 60 80 100 120

0

0.2

0.4

0.6

0.8

1

1.2

Foilage Height Diversity0.1 0.3 0.5 0.75 0.9 1 1.1

0

0.5

1

1.5

2

2.5

Management Implications

Preservation of Mangrove and Pterocarpus Forests

Preservation of Regenerating Coastal Forest andBeach Scrub (Selectively Cut Coconut Palms)

Management Techniques (e.g., water levelmanipulations, disking, burning) in HerbaceousWetlands

A) Mandri 2 (Wintering Waterfowl)B) Santa Teresa 1 (Breeding Waterfowl)

Research Needs

Limonological and Fish Population Dynamics

Pterocarpus Restoration and Community Dynamics

Evaluatory Research in Concert with Management Practices

Management Plan

Management Plan Goals

Explain Breeding and Wintering Waterfowl Management

Identify Limiting Factors toManagement and Propose Methods to Alleviate Shortcomings

Identify Costs for Implementation

Propose Time Schedule for Implementation

Biological Knowledge

Breeding Waterfowl Management (West Indian Whistling Duck, White-cheeked Pintail, Ruddy Duck, Caribbean Coot)

Time: March through August

Events: Nesting, Egg Laying, Brood Rearing, Pre-basic Molt

Physiological Demand: Protein

Management: Hemi-marsh

Breeding Waterfowl Management

Natural Marsh Cycle (Dry, Regenerating, Degenerating, Lake)

8 Year Cycle (Random and Unpredictable)

Emulate via Hydrologic and Vegetative Manipulations

Hemi-Marsh

MarshCycle

50:50

Biological KnowledgeMigrating/Winter Waterfowl Management

(Blue-winged Teal, American Wigeon, Lesser Scaup)

Time: September through February

Events: Migration, Pre-Alternate Molt, Courtship

Physiological Needs: Carbohydrates

Management: Moist-soil and Flooded Agricultural Fields

Moist-soil Management

Wetlands Dominated with Early Successional Plants

Natural Hydrology is Often Altered

Emulate via Annual Spring Drawdowns and Summer/Autumn Vegetation Manipulations

Maximize Wetland Productivity and Use

Assessing CurrentManagement Infrastructure

Water Control Capabilities(Levees and Water Control Structures)

Management Equipment(Tractors, Disks, Rotary Mowers, Pumps)

Work Load and Skill Level of Staff

Headquarters and Public Use

Identifying Inhibiting Factors to Management

Biological/Physical Factors Hydrology Uncontrolled Grazing Uncontrolled Burning Dumping

Socio-economic Factors Office and Storage Facilities Too Small Need Additional Management Equipment Biologist Has Too Many ObligationsBiologist Lacks Wetland Management Skills Research Commitments Public and DNER Interaction is Limited

Suggested Alterations to Infrastructure

Wildlife Management(Excavation, Equipment Purchasing, Personnel Training)

Public Relations(Grazing Contract, Visitor Center, Informational Brochures, Educational Signs)

Regulation of Potentially Hazardous Activities (Controlled Burning and Restricted Dumping)

DNER Public

Wetland Regulations and Permits

Clean Water Act of 1977: Section 404

Regulates Dredging and Filling of Wetlands

Permits Issued by Army Corps of Engineers

Environmental Impact Statement and/or Mitigation may be Required

Waterfowl Management Zones

Moist-soil Mangement

Hemi-marsh

Hemi-marsh

Upland Nesting

Mandri (Winter)

Santa Teresa (Breeding)

Engineering and Design

24 m

10.5 m

3 m

3 m

! Topographic Survey! Levee Design and Survey! Water Control Structure Design! Pump Station Design

Dennis L. McDonough, R.P.E.

Infrastructure Modifications

LegendContour

Existing

Excavated

Electricity

PumpWaterControlStructure

Mandri 1

SantaTeresa 1

SantaTeresa

2

Equipment to be Purchased

! Permanent and Portable Pump ! Inline Water Control Structures ! 120 hp Tractor ! Malsam Terrace Machine ! Backhoe Loader! 4 x 4 Truck! Agricultural Disk ! Rotary Mower! Seed Spreader! Drip Torches

Personnel TrainingWorkshops:

Literature:

Consulting:

! Waterfowl Ecology and Wetland Systematics (April 1996)< University of Puerto Rico-Humacao< Drs. Guy A. Baldassarre and Richard M. Kaminski

! Wetland Management (December 1996)< Mississippi and Louisiana< MSU, Noxubee NWR, Delta NF, Rockefeller Refuge

! Limnological Processes (December 1997)

! Prescribed Burning (April 1998)

! Classic Waterfowl Ecology and Wetland Management Texts< Bellrose 1976, Weller 1988, Batt et al. 1992 < Mitch and Grosselink 1986, Smith et al. 1989, Baldassarre and

Bolen 1994

! MS Coop Unit, U.S. Fish and Wildlife Service, DucksUnlimited, Inc.

Implementation Schedule and Costs

Fiscal Year 1997-98: $240,000! Topographic survey! Design and excavate contour levees! Design Electric Pump Station! Purchase 5 water control structures and a portable cristae-folie

pump! Purchase 120-hp tractor, Malsam terrace machine, offset disk,

and rotary mower! Purchase materials for controlled grazing project

! Purchase wetland publications ! Limnological workshop sponsored by Coop Unit in PR! Refuge manager attend burning short course

! Purchase and erect approximately 100 refuge boundary signs

WildlifeManagement

PersonnelTraining

PublicRelations

Implementation Schedule and Costs

Fiscal Year 1998-99: $140,000

! Purchase 1 water control structure for Mandri 3 arm! Design and build levee near Mandri 3! Install electricity ! Purchase and construct pump station! Design levee between levee between Mandri 1 and 2

WildlifeManagement

PublicRelations ! Purchase and erect educational signs for ongoingmanagement and excavation projects

Implementation Schedule and Costs

Fiscal Year 1999-2000: $200,000! Purchase 3 water control structures! Excavate levee between Mandri 1 and 2! Drain Mandri 2 after construction! Design and excavate additional contour levees in

Mandri 2! Design levees for Santa Teresa 1 and 2! Purchase front-loader backhoe ! Purchase tractor-mounted seed spreader

WildlifeManagement

PublicRelations

! Design visitor center and additional storage facilities! Purchase and erect educational signs for ongoing

management and excavation projects

Implementation Schedule and Costs

Fiscal Year 2000-01: $230,000! Purchase 2 water control structures! Excavate levees in Santa Teresa 1 and 2! Begin wetland management experiments in Mandri

unit ! Purchase drip torches

WildlifeManagement

PublicRelations

! Construct visitor center and additional storagefacilities

! Purchase and erect educational signs for ongoingmanagement and research projects

! Begin a human dimensions study of refuge users

Effects of Moist-soil Management onWintering Waterfowl at Humacao Wildlife Refuge

ExistingMandriMoist-soil

292 kcalday2500kcal kg

450 kgha138 ha 535K

Mandri 2 100 ha 450 kgha2500kcal kg 292

kcalday 385K

SeedYieldWetland Area MTE DER DUD

½ MillionDuck-use-Days 6 Months

Oct -March 3083Ducks/Day

1 MillionDuck-use-Days

5105Ducks/Day

Effects of Hemi-marsh Management on Breeding Waterfowl

= ?No Carrying Capacity Equations

Research

Current150 Females

Speculated Future 2x to 3x Nesting Density

Holistic Effects of Management at Humacao Wildlife Refuge

Number of Waterbirds Success Rate

Number of Visitors Attitudes Money toCommunity and DNER

Number of Fish

Acknowledgments

DNER USFWS UPR MSUM. Corbet

J. DiazA. Mojica

R. PimentelJ. ReyesI. Rosa

R. MatosJ. ChabertJ. Berrios

J. OlandF. Lopez

S. SilanderB.Yoshioka

C. Diaz

C. BaergaE. Hernandez

R. Perez

R. KaminskiJ. Hargreaves

J. BowmanJ. B. DavisR. Minnis

J. D. TaylorR. Brown

J. MacGownS. McDaniel

G. Baldassarre

SUNY

DUR. Melinchuk

VolunteersN. Ayala, D. Castillo, J. Cruz, Y. Cruz, E. Esquilin, U. Feliciano, M. Lopez, N.Lopez, R. Lopez, A. Martinez, J. Martinez, D. Miller, N. Perez, A. Puente, I.Ramon, F. Rios, M. Rivera, O. Rivera, H. Torres, W. Velez, and J. Wade

Funding and Support

U.S. Fish and Wildlife Service

Project FW-10

Puerto Rico Department of Natural ResourcesDivision of Reserves and Refuges

Mississippi State UniversityCooperative Fish and Wildlife Research Unit

Department of Wildlife and Fisheries

Preguntas?