Contents

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2. Contents Reef / Seagrass / Mangrove Relationships What is Seagrass? Where does seagrass grow? Seagrass Diversity & Anatomy Seagrass Community Physical Parameters Inhabitants of Seagrass Seagrass Ecology / Services Nurseries Threats to Seagrass CCMI Seagrass Research

3. Reefs, Sea Grasses & Mangroves Relationships Coral reefs, seagrass beds and coastal mangrove systems are closely connected.

4. Seagrass – Mangroves – Reefs Sea grasses trap sediment and slow water movement Corals thrive in clear, sediment-free water Seagrass benefits coral by reducing sediment loads. Barrier reefs form lagoons protected from waves, which allows mangrove and seagrass communities to develop. Mangroves trap sediment, reduce the load on seagrass and corals. Seagrass sediments form substrate that can be colonized by mangroves.

5. What is seagrass? The only true flowering plants that can live completely underwater! Possess true roots, stems and leaves Require certain physical conditions to grow Provide food and habitat for many creatures Main diet of juvenile sea turtles, manatees, crabs, shrimp, and a variety of juvenile fishes

6. Where is seagrass in the world? Seagrass beds cover less than 10% of the world's shallow coastal waters, but are important nursing grounds for commercial fish species Greatest diversity: Indo-Pacific region Located along the coast of all continents except Antarctica

7. Where does seagrass grow? Must be fully submerged Require saltwater to grow Thrive in warm temperatures: 20-30°C Require light for photosynthesis Grow in shallow, coastal waters Root system needs a stable soft-bottom habitat

8. Diversity of Seagrass

9. Biodiversity of Seagrass

10. Turtle grass anatomy

11. Types of Sea grasses Left: wigdeon grass, Johnson’s grass; Right top to bottom: star grass, manatee grass, shoal grass; Below: Turtle grass, Paddle grass

12. Location Turtle- Florida, Caribbean, Bermuda, area between Gulf of Mexico and Venezuela Manatee- Florida, Bermuda, Bahamas, Gulf of Mexico, Caribbean Shoal- North Carolina, along the Atlantic, coast of Gulf of Mexico, Caribbean Johnson’s- Indian River Lagoon Paddle- near Indian River Lagoon, Gulf of Mexico, Caribbean, Indo-West Pacific Star- Florida, Bahamas, Texas, West Indies Widgeon- Atlantic coast (New Foundland-Texas)

13. Seagrass Community Food Chain

14. Physical Parameters of Seagrass Communities Temperature Typical Caribbean shoreline temperature: 26-30°C Thalassia thrives in 20-30°C Large scale senescence (leaf loss) occurs in extreme temperatures Salinity Greatest photosynthetic activity between 34-36 psu Leaf loss and drop in photosynthetic activity below 24 psu Significant damage caused by lots of fresh water runoff during storms or water management (i.e. the Everglades) Current and Sediment Depth Slower current = greater sediment depth Greater sediment depth = increases in seagrass bed elevation, leaf density and leaf length

15. Inhabitants of Seagrass Beds Infauna Protozoan and metazoan invertebrates that burrow in the sediment and rhizomes Feed on sediments, filter feed or feed in water column nocturnally Epiphytes Organisms living on stems and leaves Epiphytic algae, bryozoans, polychaetes, small amphipods Epifauna Organisms living on the sediment Conspicuous invertebrates – starfish, sea urchins, queen conch Nekton Organisms swimming in canopy – fishes and sea turtles

16. Conch in Sea Grass Sea grasses grow in just a few inches of water. Sea grasses need a lot of light to photosynthesize, so they only grow to depths to 3 - 4’.

17. Sting Ray This sting ray is a predator eating small squid, shrimp and other animals that it finds in the grass. They look scary, but they are really friendly and don’t bite. They eat by sucking up their prey as they have no teeth.

18. Green Sea Turtles This turtle swims above the sea grass in the lagoon. Sea grass is a favorite food of green sea turtles.

19. Manatees& Dungeons Manatees are herbivores that also live off of the sea grass. They are found mostly in Florida waters and in the Great Barrier Reef, Australia. They are slow swimmers and prefer grazing in quiet, shallow areas.

20. Ecosystem services: Seagrass beds protect against shoreline erosion, home for a huge diversity of marine life, food for turtles, and help to create clear waters.

21. The Ecological Roles of Seagrass Ecological Importance: Nursery habitat Foraging habitat Stabilize sediments Absorb excess nutrients Also provide coastal protection from erosion and water purification, absorb CO2, and stabilize sediments

22. Seagrass Beds as Nurseries Seagrass ecosystems host a rich diversity of species, including threatened and commercially important species: Dugongs Seahorses Conch Grouper Sea turtles Snapper Shrimp Blue crabs Scallops What other species do we see in seagrass beds?

23. Threats to Seagrass Ecosystems fishing by benthic trawling clearance for beaches and tourist facilities fishing by benthic trawling clearance for beaches and tourist facilities

24. Threats to Seagrass Ecosystems

25. Natural Threats Wasting disease (caused by marine slime mold?) Storms Wind-driven waves Marine animals disturbing sea grass Imbalance in marine grazers / predators

26. Protection Boating Do not disturb eelgrass beds (avoid if possible) Stay within marked channels Slower in shallower areas Make propeller wash effect lower in shallower areas Use pumpout stations to dispose of waste Shell fishing Do not use clam rakes or tongs in areas of eelgrass When dredging for bay scallops- dredge should be rigged and working properly

27. Protection (cont’d) Daily Activities Do not put trash or pollutants in the estuary Do not use harmful fertilizers and pesticides Wash Cars in commercial car wash or on lawn (prevents excess soap from draining into local waterways) Educate others about the benefits of sea grass

28. Seagrass in the Protection of the Reef This aerial was taken from the airplane above Little Cayman Island. A patch reef and areas of sea grass can be seen in the lagoon between the land and the fringing reef.

29. Patch Reef Ecological Importance: Nursery habitat Foraging habitat Stabilize sediments Absorb excess nutrients

30. Patch Reefs

31. Green Sea Turtles Sea turtles spend their juvenile years eating and growing in near-shore habitats such as patch reefs. Once they reach adulthood they migrate to different feeding grounds.

32. Seagrass Ecology Angiosperms = True flowering plants True roots, stems, flowers and leaves Five Characteristics of Ecological Success: Ability/need for saline medium Function physiologically while fully submerged Well-developed anchoring system Ability to reproduce while submerged Ability to compete for space and resources

33. Seagrass Study Methods CCMI measures standing crop biomass (above ground) and total biomass (standing crop + below ground) Four randomly placed cores per site Light attenuation using Secchi disk 4 random quadrats along 5 transects to evaluate % cover per species

34. Seagrass Study Methods Use corer to get 40-50 cm deep, rotating through the sediment After collection: Sort by species Sort Thalassia by material: Green leaves Non-green leaves and bundle sheath Rhizomes Live roots Dead belowground material Sort other species as green or non green Clean samples from carbonates and sediments Toothbrush HCl acid soak – 5 min; Rinse Dry to constant weight to calculate dry weight per m2

35. Seagrass Productivity Studies Six 10x20 cm quadrats randomly marked at each site all the seagrass within each quadrat will be marked poke a needle hole a short distance above the green-white interface of the leaves, making sure to do all leaves on a shoot at once return to collect them after 10 days 1) Daily Production = (Weight of new leaves + Weight of old growth) x 50 # of days marked 2) Turnover Rate (%/day) = (Daily Production x 100)/(Standing Crop)

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37. Citations http://www.flmnh.ufl.edu/Fish/southflorida/seagrass/profiles.html http://www.flmnh.ufl.edu/fish/southflorida/seagrass/importance.html#product http://www.unep-wcmc.org/marine/seagrassatlas/introduction.htm http://www.sms.si.edu/IRLspec/Seagrass_Habitat.htm http://www.dnr.state.md.us/boating/pumpout/pumpout.html www.wikipedia.org