Aquatic Ecosystems

Psalm 29 Psalm 93 Ascribe to the Lord, O heavenly beings, ascribe to the Lord glory and strength. 2  Ascribe to the Lord the glory due his name; worship the Lord in the splendor of holiness. 3  The voice of the Lord is over the waters; the God of glory thunders, the Lord, over many waters. 4  The voice of the Lord is powerful; the voice of the Lord is full of majesty. The Lord reigns; he is robed in majesty; the Lord is robed; he has put on strength as his belt. Yes, the world is established; it shall never be moved. 2  Your throne is established from of old; you are from everlasting. 3  The floods have lifted up, O Lord, the floods have lifted up their voice; the floods lift up their roaring. 4  Mightier than the thunders of many waters, mightier than the waves of the sea, the Lord on high is mighty! 5  Your decrees are very trustworthy; holiness befits your house, O Lord, forevermore.

Aquatic ecosystems are determined primarily by the depth, flow, temperature, and chemistry of the overlying water. Depth: distance from shore, amount of light Temperature: polar, tropical, temperate Chemistry: salt, nutrient, and oxygen content INTRODUCTION

Freshwater

Flowing Water Rivers, streams, creeks, and brooks Organisms have features that enable them to attach to rocks, move with the current, or move against the current. Usually originate from underground springs in the hills/mountains Lots of oxygen Farther downstream, sediments accumulate allowing plants and animals to make their homes.

Standing Water Lakes, ponds Water flows in and out Circulation within distributes nutrients and oxygen Still water supports small organisms like: Plankton – weakly swimming; live in fresh/salt water Phytoplankton: single-celled algae; base of many food webs Zooplankton: planktonic animals; feed on phytoplankton

Wetlands Water either covers soil, or soil is near the surface during part of the year Fresh/salty/brackish Flowing/standing Home to insects, fish, and birds (etc.) Bogs (acidic, formed by “kettle holes”), marshes (shallow, along rivers), swamps (look like flooded forests)

Estuaries

Estuaries Wetlands that form where water meets the sea Shallow, salt & fresh, Plants, algae, and photosynthetic & chemosynthetic bacteria enter the food web as detritus (decaying organic matter) Clams, worms, sponges A spawning and nursery grounds for many organisms Fish, shrimp, crabs Waterfowl Salt marshes (temperate, salt-tolerant grasses), Mangrove swamps (tropical, salt-tolerant trees)

Marine Ecosystems

Intertidal Zone Organisms experience extreme changes in surroundings: covered in seawater – then exposed to sunlight, air, temperature change – as well as waves and strong currents. Zonation – prominent banding of organisms that live in a particular habitat

Coastal Ocean Extends from the low-tide mark to the outer edge of the continental shelf Shallow enough for photosynthetic organisms Kelp forests Grow fast Support complex food web

Coral Reef Warm, shallow, tropical Composed largely of coral animals Wide biodiversity Algae supply nutrients for coral, and coral supply framework (of calcium carbonate) on which algae can grow.

Open Ocean “oceanic zone” Largest marine zone (90%!) 500-11,000 meters deep Generally low nutrients and productivity, only smallest producers are supported Great surface area… So most of photosynthetic activity on earth happens in the photic zone of the open ocean Fish, whales, octopuses, etc. In deep open ocean – high pressure, frigid temperatures, total darkness

Benthic Zone Benthos = organisms that live attached to or near the bottom of the ocean Extends along ocean floor from the coastal ocean through the open ocean Benthic ecosystems often depend on nutrients that drift down from the photic zone Some chemosynthetic producers dwell near deep- sea vents