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08A SANDY BEACHES. I. Biological characteristics. A. Zonation 1. Broad 2. Not well defined B. Species diversity low C. Density & numbers of individuals can be very high. Maritime Forest. Dune. Beach Front. Surf. Beach zones at San Blas Peninsula, Port St. Joe, FL
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I. Biological characteristics A. Zonation 1. Broad 2. Not well defined B. Species diversity low C. Density & numbers of individuals can be very high
Maritime Forest Dune Beach Front Surf Beach zones at San Blas Peninsula, Port St. Joe, FL http://www.nature.com/scitable/knowledge/library/coastal-dunes-geomorphology-25822000B
Zones • A. Surf Zone • 1. Physical characteristics • a. Usually high energy • (1) Waves create turbulence • (2) Field trip sites • (a) East side • i Low energy waves • ii Protected by Sand and Dauphin Islands • (b) West side has higher energy waves • b. Water is saturated with O2
Surf Zone (continued) • 2. Biological characteristics • a. Primary producers • (1) Planktonic only • (2) Density can be high during phytoplankton blooms
Biological Characteristics of Surf Zone (continued) • Invertebrates are buried [Add striped hermit Clibanarius vittatus] • (1) Diopatra • (a) Polychaete worm • (b) Builds tubes with mucus that hardens into a parchment-like material • (c) Animal attaches small shells and plant material to tube • (d) Worm scavenges/preys upon… • i …organisms that float by • ii …organisms that settle and live on tube • (e) Usually just the upper portion of the tube is collected (without the worm)
Plumed worm Diopatra cuprea (Polychaeta) Ruppert & Fox, 1988, Seashore Animals of the Southeast, Univ South Carolina Press, p. 197.
Invertebrates are buried (continued) • (2) Soda straw worm • (a) Polychaete worm • (b) Builds compressible sand tubes that can accumulate in drifts/windrows on beach front • (c) Preys upon zooplankton
Soda Straw worm Kinbergonuphis (Polychaeta) Ruppert & Fox, 1988, Seashore Animals of the Southeast, Univ South Carolina Press, p. 195
2. Biological characteristics of surf zone (continued) • Vertebrate predators common • (1) Feed behind breaking waves • (2) Many species of juvenile fish prey upon small invertebrates uncovered by wave turbulence • (3) Southern and Cow-nosed Rays feed on larger invertebrates
Southern Stingray Dasyatis americana Amos & Amos, 1989, Atlantic and Gulf Coasts, Alfred A. Knopf, pl 425
The mouth of Cow-nosed rays is well adapted for crushing bivalves Photo: Jack O’Brien, 2012
The Giant Atlantic Cockle Dinocardium robustum is common in the sub-tidal zone off Sand Island http://txmarspecies.tamug.edu/invertdetails.cfm?scinameID=Dinocardium%20robustum
Crushed remains of cockles, the result of cow-nosed ray predation, have become quite common on local beach fronts Photo: Jack O’Brien, 2012
c. Vertebrate predators common (continued) (4) Bottle-nosed dolphins Tursiops truncatus (a) Pods common off western ends of Gulf Coast Barrier Islands (b) Strong currents on island west ends stir up sand and expose invertebrates (c) Dolphins feed on the fish feeding on the invertebrates
Surfing Dolphins http://www.google.com/imgres?imgurl=http://www.peconicpuffin.com/.a/6a00d8341c890753ef0105358cc9d6970b-800wi&imgrefurl=http://www.peconicpuffin.com/the_peconic_puffin/dolphins/&h=540&w=720&sz=61&tbnid=kjQy1CGOvXE9HM:&tbnh=92&tbnw=122&zoom=1&usg=__7ayEPOoJCnwD43XhyWvG0dnOyOI=&docid=9HpoSNAicow_nM&sa=X&ei=oAb3UffsHq2v4APUr4CwDg&sqi=2&ved=0CDgQ9QEwAw&dur=530#imgdii=_
Maritime Forest Dune Beach Front Surf Beach zones at San Blas Peninsula, Port St. Joe, FL http://www.nature.com/scitable/knowledge/library/coastal-dunes-geomorphology-25822000B
B. Beach Front Zone 1. Physical characteristics a. Moist (capillary action of sand retains water) b. Sunny in daytime c. Substrate is unstable due to wave action
1. Physical characteristics of beach front zone (continued) d. BERM (1) Defines upper limit (2) Sharp edged “cliff” (1-2 feet high on Sand Island) formed by scouring of waves (3) Indicates the limit of the highest high tide
The Sand Island berm on the east facing beach is fairly shallow due to low energy waves Photo: Jack O’Brien, 2012
Mainland Beaches that receive high energy waves have well-formed berms Berm at St. Andrew’s Park, Panama City, FL Photo: Jack O’Brien, August 9, 2013
Physical Structures (continued) • e. WRACK LINE • (1) Well-defined accumulation of debris • (2) Formed from… • (a) Flotsam/jetsam left at high tide • (b) Buried items uncovered by breaking waves
Wrack Line composed of Sargassum, Sand Island Photo by Jack O’Brien, June 2013
Typical berm & wrack line composed of shells Photo: A. Tabor, 2013
B. Beach Front (continued) • 3. Biological characteristics • a. Animals are cryptic • b. More activity at night than during day • c. Dense aggregations common on many beaches (Not usually seen on Dauphin Island beaches)
B. Beach Front (continued) • Trophic Interactions • Energy input • (1) Pennate diatoms • (a) Primary producers • (b) Adhere to surface of sand grains • (c) Will form mats in low areas that are relatively protected from tidal flushing • (2) Carcasses wash in from ocean
Carcass of Southern Ray on Sand Island Photo: Jack O’Brien, June 2013
4. Trophic interactions on beach front (continued) • b. MEIOFAUNA • (1) Primary consumers • (2) Live interstitially between sand grains
Trophic Interactions on Beach Front (continued) • c. Secondary consumers • (1) Deposit feeders • (a) Lugworm • polychaetes • (b) Ingest sand & • digest meiofauna • (c) Leave casts of • processed • sand around hole • (d) J-shaped burrow makes them hard to dig up
Lugworm burrow openings and cast http://www.sms.si.edu/Irlspec/Arenic_crista.htm
c. Secondary consumers (continued) (2) Suspension feeders (a) Feed on material suspended by waves (b) Donax, coquina clam
Amos & Amos, 1989, Atlantic and Gulf Coasts, Alfred A. Knopf, pl 131 Photo by A. Tabor, 2013 Coquina Surf Clam Donax variabilis
c. Secondary consumers (continued) (3) Emerita (a) Mole or sand crabs (b) Feathery antennae catch particles as waves recede from beach
Mole Crabs / Sand Crabs, Emerita Lippson & Lippson, , 1984, Life in the Chesapeake Bay, Johns Hospkins Uni. Press, p 28
Characteristic sand ripples on a beach front in Santa Barbara, CA indicate the presence of Emerita Photo: Jack O’Brien, June 2013
Students in UC Santa Barbara marine biology class counting and sexing Emeritaafter sorting Photo: Jack O’Brien, June 2013
Emerita can be found in great numbers on many beaches Photo: Jack O’Brien, June 2013
Emerita in a sorting container Photo: Jack O’Brien, June 2013
Trophic Interactions on Beach Front (continued) • d. Tertiary consumers (Top carnivores) • (1) Some bird species follow waves as they recede • (a) Godwits • I Long bills • ii Eat lugworms and bivalves
Natl. Audubon Soc. Field Guide to N. Amer. Birds (Eastern Region), 1996
(1) Bird species that follow receding waves on beach front (continued) (b) Sandpipers i Shake their bills ii Liquify sand
Natl. Audubon Soc. Field Guide to N. Amer. Birds (Eastern Region), 1996
CHEAP THOUGHTS BY JACK O’BRIEN
WHAT DID SEAGULLS EAT BEFORE THERE WAS HUMAN GARBAGE… http://www.google.com/imgres?imgurl=http://wiseacre-gardens.com/birds/sea-gull-trash2.jpg&imgrefurl=http://wiseacre-gardens.com/wordpress/sea-gull-smorgasbord/&h=479&w=600&sz=94&tbnid=EqQP7Ri5fd15LM:&tbnh=90&tbnw=113&zoom=1&usg=__IuVqY9zUMyFXWG7LlOgOyu8O4j4=&docid=3OcJSxCy2xwfAM&sa=X&ei=mR_3UbnEM4_g8wSnm4CwDQ&ved=0CCwQ9QEwAA&dur=1302#imgdii=EqQP7Ri5fd15LM%3A%3BKW1sr3SOoGaQKM%3BEqQP7Ri5fd15LM%3A
…AND PEOPLE WHO FEED THEM FRENCH FRIES? http://en.wikipedia.org/wiki/File:Catching_a_snack_(5597547033).jpg
Trophic Interactions on Beach Front (continued) • e. Scavengers • (1) Feed on dead organisms that are cast up onto beach from ocean • (2) Seagulls active in day
http://www.google.com/imgres?imgurl=http://www.fotoartglamour.com/pictures/seagull-eating.JPG&imgrefurl=http://www.fotoartglamour.com/page/3&h=625&w=800&sz=48&tbnid=2y6ZJQYEUt4X0M:&tbnh=94&tbnw=120&zoom=1&usg=__UxUep2Y7J81UZZvIUtQhGWp6IGw=&docid=RMOPHKZgcBEcrM&sa=X&ei=eBv3Uf_BDIi49QSpt4C4Cg&ved=0CGUQ9QEwEg&dur=525http://www.google.com/imgres?imgurl=http://www.fotoartglamour.com/pictures/seagull-eating.JPG&imgrefurl=http://www.fotoartglamour.com/page/3&h=625&w=800&sz=48&tbnid=2y6ZJQYEUt4X0M:&tbnh=94&tbnw=120&zoom=1&usg=__UxUep2Y7J81UZZvIUtQhGWp6IGw=&docid=RMOPHKZgcBEcrM&sa=X&ei=eBv3Uf_BDIi49QSpt4C4Cg&ved=0CGUQ9QEwEg&dur=525
e. Scavengers on beach front (continued) (3) Ghost crabs (a) Ocypode (b) Their burrows can be… …located as far up as the Dune Zone …deeper than a meter
Carcass of Southern Ray with burrows of opportunistic scavenging ghost crabs Photo: Jack O’Brien, Sand Island, June 2013
(3) Ghost crabs (continued) (c) Active at night (b) Thick setae line opening to gill chamber i Crab buries itself in wet sand at bottom of burrow ii Water drawn up into setae by capillary action