1. CHAPTER 15 Animals of the Benthic Environment

2. Distribution of benthic organisms  More benthic productivity beneath areas of high surface primary productivity – 98% of marine species are benthic Mainly on continental shelves Affected by surface ocean currents Fig. 15.1

3. Benthic organisms on rocky shores  Epifauna (on top) Attached to substrate (e.g., marine algae) Move on/over seafloor (e.g., crabs, snails)  Moderate diversity of species Greatest animal diversity at tropical latitudes Greatest algae diversity at mid-latitudes http://dnr.metrokc.gov/wlr/waterres www.portfolio.mvm.ed.ac.uk/studentwebs/session2

4. Intertidal zonation (rocky shore) Fig. 15.2 a

5. Intertidal zonation (rocky shore)  Spray zone (supratidal) Must Avoid drying out Many animals have shells Few species of marine algae Fig. 15.2b www.mbari.org/staff/conn/botany/methods Monterey Bay, CA

6. Intertidal zonation (rocky shore)  High tide zone Avoid drying out so animals have shells Marine algae—rock weeds with thick cell walls http://www.woodbridge.tased.edu.au/mdc/Species%20Register/Barnacle-Tetra.jpg http://www.ecology.org/ecophoto/algae/Thumbnails/Plant%20Images-10360.jpg

7. Intertidal zonation (rocky shore)  Middle tide zone More types of marine algae Soft-bodied animals http://www.wallawalla.edu/academics/departments/biology/rosario/inverts/Mollusca/Bivalvia/Mytiloida/Mytilidae/Pisaster%20Predate%20mussels.jpg Pisaster – sea star, mussel predator http://www.dfw.state.or.us/mrp/shellfish/commercial/Images/flat_abalone.jpg Abalone

8. Intertidal zonation (rocky shore)  Low tide zone Abundant algae Many animals hidden by sea weed and sea grass Crabs abundant in all intertidal zones http://www.fisherycrisis.com/chondrus/fig32.JPG

9. Benthic organisms on sediment-covered shores  Similar intertidal zones  Less species diversity Greater number of organisms infauna Mostly infauna – burrow into sediment  Microbial communities http://bivalves.info/Donax_hanleyanus.jpg Coquina (Donax) http://www.theseashore.org.uk/theseashore/Resources%20for%20seashoreweb/Images%20for%20New%20Pages/Donax.JPG Coquina with valves extended

10. Intertidal zonation (sandy shore) Fig. 15.8

11. Sandy beaches  Animals burrow  Bivalve mollusks  Annelid worms  Crustaceans  Echinoderms  Meiofauna Fig. 15-9 http://photography.nationalgeographic.com/staticfiles/NGS/Shared/StaticFiles/Photography/Images/POD/g/ghost-crab-hiding-760340-sw.jpg Ghost crab hiding Mole crab

12. Mud flats  Eelgrass and turtle grass common  Bivalves and other mollusks  Fiddler crabs http://www.lacoast.gov/articles/bms/1/3_mud_flat_ground_view.jpghttp://www.sms.si.edu/irlspec/images/06PhotoContest/06DeWolfeH3.jpg http://www.weeksbay.org/photo_gallery/shorebirds/SEMIPALMATED%20PLOVER.jpg

13. Shallow ocean floor  Continental shelf  Mainly sediment covered  Kelp forest associated with rocky seafloor Also lobsters Oysters http://www.ianskipworth.com/photo /pcd1742/kelp_forest_15_4.jpg http://www.teara.govt.nz/NR/rdonlyres/ED9A6951-7B98-4AD2-A6A0-CA633137BE7C/74562/p4595doc.jpg http://www.lifesci.ucsb.edu/~c_white/images/Lobsters%20in%20San%20Diego.JPG

14. Figure 15.14a,b

15. Figure 15.14c

16. Coral reefs  Most coral polyps live in large colonies  Hard calcium carbonate structures cemented together by coralline algae www.mpm.edu/imageswww.gettankedaquariums.com http://www.h2o-mag.com/issue6/images_issue6/coral-01-copy.jpg

17. Coral reefs  Coral reefs limited to Warm (but not hot) seawater Sunlight (for symbiotic algae) Strong waves or currents Clear seawater Normal salinity Hard substrate www.waterfrontchattanooga.com/Newsroom/High_reshttp://www.ee.bilkent.edu.tr/~aytur/pg

18. Reef-building corals Fig. 15-17

19. Symbiosis of coral and algae  Coral reefs made of algae, mollusks, foraminifers as well as corals mutualistic relationship zooxanthellae  Hermatypic coral mutualistic relationship with algae – zooxanthellae Algae provide food Corals provide nutrients http://www.reefed.edu.au/explorer/images Soft coral polyp (Lobophytum compactum). Green shows the polyp tissue, while the red shows the zooxanthellae. www.bigelow.org/reefwatch2001/coral_reefs/images

20. Coral reef zonation  Different types of corals at different depths Fig. 15.19

21. Importance of coral reefs  Largest structures created by living organisms Great Barrier Reef, Australia, more than 2000 km (1250 m) long  Great diversity of species  Important tourist locales  Fisheries  Reefs protect shorelines http://www.sheppardsoftware.com/images/Oceania/factfile/GreatBarrierReef-EO.jpg Great Barrier Reef from space

22. Coral bleaching  Coral bleaching occurs when symbiotic zoothanthellae algae is removed or expelled  Associated with high water temperatures Figure 15B

23. Humans and coral reefs  Activities such as fishing, tourist collecting, sediment influx due to shore development harm coral reefs  Sewage discharge and agricultural fertilizers increase nutrients in reef waters Hermatypic corals thrive at low nutrient levels Phytoplankton overwhelm at high nutrient levels Bioerosion of coral reef by algae-eating organisms http://daac.gsfc.nasa.gov/oceancolor/images/coral_reef_algae.jpg Coral covered with macroalgae

24. ○ Other problems Smoothering by dredging, runoff Fishing practices, harvesting Pollution Global warming http://images.wri.org

25. Large vs. small reef fish: Fishery management regulations such as minimum sizes allow fishermen to keep only the largest fish. As shown by the red snapper example, the largest fish produce the most eggs. One 24-inch red snapper produces the same number of eggs as 212 17-inch red snapper. So, by selectively removing the largest fish, the fishery removes the fish that have the greatest potential for producing more fish. ttp://oceanexplorer.noaa.gov/explorations/02sab/logs/aug05/media

26. Benthic organisms on the deep seafloor  Little known habitat – only accessable via dredge and some submersibles and ROVs  Bathyal, abyssal, hadal zones Little to no sunlight About the same temperature About the same salinity Oxygen content relatively high Pressure can be enormous Bottom currents usually slow http://www.whoi.edu/science/B/people/sbeaulieu/rad_patch_by_mound.jpghttp://library.thinkquest.org/17297/images/alvin.gif http://www.amnh.org/nationalcenter/expeditions/blacksmokers/images/large/amnh19_18.jpg

27. Food sources in deep seafloor  Most food sinks from surface waters  Only 1 – 3% of euphotic food present  Special adaptations for detecting food Fig. 15.22

28. Deep-sea hydrothermal vent biocommunities  First discovered 1977  Chemosynthesis  Archaea use sea floor chemicals to make organic matter  Unique communities Tube worms Giant clams and mussels Crabs Microbial mats http://i.treehugger.com/images/2007/10/24/deep-sea%20hydrothermal%20vent-jj-001.jpg www.jamstec.go.jp/jamstec/organi/GOIN

29. Figure 15.27

30. Figure 15.25b Chemosynthesis Chemosynthesis Archaea use sea floor chemicals to make organic matter

31. Global hydrothermal vent fields Fig. 15.24

32. Figure 15.29b