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Marine Biology. Lecture 7: Estuaries. What is an estuary?. Definition “Partially enclosed embayment where fresh and salt water meet.” Biological perspective One of the most biologically productive types of ecosystems in the world. Types of estuaries in Oregon. Drowned river mouth
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Marine Biology Lecture 7: Estuaries
What is an estuary? • Definition • “Partially enclosed embayment where fresh and salt water meet.” • Biological perspective • One of the most biologically productive types of ecosystems in the world
Types of estuaries in Oregon • Drowned river mouth • River dominated • Bar built • Blind
Bar-built estuary • Cape Hatteras, North Carolina
Bar Built Estuary Stony Brook Harbor, Long Beach
Salinity profiles • Positive “salt wedge” estuary
Salinity classifications (cont.) • Negative (“evaporate”) estuary
Other physical characteristics • Substrate • General description • Relationship to salinity
Other physical characteristics (cont.) • Temperature • Wave action and currents • Turbidity • Oxygen
Estuarine food webs • Sources of energy • Organic matter • Phytoplankton • Algal mats • Plants • Primary consumers • Planktovores • Detritovores • Key predators
Common estuarine animals in Oregon • Worms (a variety) • Clams (a variety) • Snails (in some) • Ghost shrimp (Calianassa californiensis) • Sand shrimp (Crangon spp.) • A variety of crabs • Cancer magister can be found in estuaries, although they are stenohaline and found near the bottom • Predatory fish • Birds
Common estuarine organisms in Oregon • Worms: a variety • Abarenicola sp.
Common estuarine organisms in Oregon Saxadoma nutalli: butternut clam Macoma nasuta: bent-nosed clam Photos: Melissa Phipps Protothaca staminia: littleneck Mya arenaria: soft-shelled clam
Common estuarine organisms in Oregon • Snails • Cerithidea sp.: California horn snail
Common estuarine organisms in Oregon • Callianassa californiensis: the ghost shrimp
Common estuarine organisms in Oregon • Crangon sp.: the sand shrimp
Salt Marshes Mangroves