Seagrasses: Underwater Seagrasses: Underwater Food FactoriesFood FactoriesA Tampa Bay Example A Tampa Bay Example

of a Food Webof a Food Web

Prepared by: Prepared by:

NOE P. MENDEZNOE P. MENDEZCENTRAL MINDANAO UNIVERSITY (CMU)CENTRAL MINDANAO UNIVERSITY (CMU)

npolomendez@gmail.comnpolomendez@gmail.com

Seagrasses: So What Are They?Seagrasses: So What Are They? Seagrasses are Seagrasses are

flowering underwater flowering underwater plantsplants

Found at shallow Found at shallow depths in estuaries: depths in estuaries: bays and lagoons bays and lagoons with good water with good water qualityquality

What are some What are some reasons that these reasons that these plants can grow only plants can grow only in shallow water?in shallow water?

Source: http://tbep.org/portrait/habitats.html

FlowersLeaves

Rhizome (underground stem)

Line drawing of Manatee grass (Syringodium filiforme)

They grow in shallow They grow in shallow water because...water because...

Seagrasses require good water clarity and Seagrasses require good water clarity and quality to survive. quality to survive.

They possess structures similar to They possess structures similar to terrestrial plants like roots, leaves and terrestrial plants like roots, leaves and flowers.flowers.

They need sunlight to penetrate the water They need sunlight to penetrate the water in order to perform photosynthesis. in order to perform photosynthesis.

3 Types of Seagrasses in 3 Types of Seagrasses in Tampa BayTampa Bay

turtle grassturtle grass(yes, sea turtles eat it!)(yes, sea turtles eat it!)

shoal grassshoal grass (usually the first(usually the first species to appear)species to appear)

manatee grassmanatee grass(yes, manatees love it!)(yes, manatees love it!) Pictures from

http://www.dep.state.fl.us/coastal/habitats/seagrass/awareness/healthy_images.htm

So, Why are Seagrass Beds So, Why are Seagrass Beds Important?Important?

As a nursery environment, seagrasses As a nursery environment, seagrasses support small fish, shrimp, and crabs that support small fish, shrimp, and crabs that hide among the blades and feast on hide among the blades and feast on decaying leaves.decaying leaves.

They help stabilize shifting sands on the They help stabilize shifting sands on the bottom of the bay.bottom of the bay.

They improve water clarity by trapping They improve water clarity by trapping fine sediments and particles.fine sediments and particles.

The Decline of Seagrass BedsThe Decline of Seagrass Beds

After 1950, the seagrass beds in Tampa After 1950, the seagrass beds in Tampa Bay seriously declined.Bay seriously declined.

The major reason for decline in seagrass The major reason for decline in seagrass beds is probably water pollution.beds is probably water pollution.

As a class, list reasons why water pollution As a class, list reasons why water pollution in Tampa Bay would increase after 1950.in Tampa Bay would increase after 1950.

Reasons Why Water Pollution Reasons Why Water Pollution Would IncreaseWould Increase

Population increased; more garbage, sewage dumped Population increased; more garbage, sewage dumped into bayinto bay

More people lived near the Bay; more workplaces built More people lived near the Bay; more workplaces built More cars, trucks -- air pollution (mercury, NOx, lead ends up in More cars, trucks -- air pollution (mercury, NOx, lead ends up in

water)water) Oil, gasoline spills from cargo shipsOil, gasoline spills from cargo ships Port of Tampa receives more cargo ships (sewage, Port of Tampa receives more cargo ships (sewage,

garbage and fuel spills from ships)garbage and fuel spills from ships) More nitrogen entered the bay:More nitrogen entered the bay:

Sewage treatment plants were not like today (untreated sewage Sewage treatment plants were not like today (untreated sewage common in bay)common in bay)

Industries dumped chemically polluted waste directly into waterIndustries dumped chemically polluted waste directly into water No real government control of water pollution before No real government control of water pollution before

19721972

Compare the Seagrass BedsCompare the Seagrass Beds40,420 ac in 1950 26,920 ac in 1996

A Big ImprovementA Big Improvement Improvements in water quality have fueled Improvements in water quality have fueled

steady gains in seagrass recoverysteady gains in seagrass recovery

Tampa Bay is now gaining about 500 Tampa Bay is now gaining about 500 acres of seagrass a year, and has about acres of seagrass a year, and has about 29,647 acres baywide as of 2008 29,647 acres baywide as of 2008

The goal is to get The goal is to get to 38,000 acresto 38,000 acres

Seagrass Change Through The Seagrass Change Through The YearsYears

Life in a Tampa Bay Seagrass BedLife in a Tampa Bay Seagrass Bed

Bacteria, FungiBacteria, Fungi AlgaeAlgae InvertebratesInvertebrates FishFish ReptilesReptiles BirdsBirds MammalsMammals

Life in a Tampa Bay Seagrass BedLife in a Tampa Bay Seagrass Bed

Bacteria, FungiBacteria, Fungi Decompose seagrass leavesDecompose seagrass leaves

AlgaeAlgae Grows on seagrass leaves, becomes detritusGrows on seagrass leaves, becomes detritus

InvertebratesInvertebrates FishFish ReptilesReptiles BirdsBirds MammalsMammals

Life in a Tampa Bay Seagrass BedLife in a Tampa Bay Seagrass Bed

Bacteria, FungiBacteria, Fungi AlgaeAlgae Invertebrates – scallops, crabsInvertebrates – scallops, crabs Fish – snook, sharksFish – snook, sharks Reptiles – sea turtlesReptiles – sea turtles Birds – wading birdsBirds – wading birds Mammals - manateesMammals - manatees

THANK YOU THANK YOU FOR FOR

LISTENING!LISTENING!

NOE P. MENDEZNOE P. MENDEZCentral Mindanao UniversityCentral Mindanao University

npolomendez@gmail.comnpolomendez@gmail.com