Water, Water Everywhere! If you poured all the world’s water on the United States and could contain it, you’d create a lake 90 miles deep. How much water is that? Roughly 326 million cubic miles, according to the U.S. Geological Survey. Some 72 percent of Earth is covered in water, but 97 percent of that is salty and no good for drinking.watersalty So, some facts about the freshwater: 70 percent of freshwater is locked in ice caps Less than 1 percent of the world’s freshwater is readily accessible 6 countries (Brazil, Russia, Canada, Indonesia, China and Colombia) have 50 percent of the freshwater reserves One-third of the world’s population lives in “water-stressed” countries

AQUATIC LIFE ZONES Section 5-2

Aquatic “Biomes” are determined by the salinity of the water Saltwater/Marine 1. open sea 2. estuary 3. coast line 4. coral reef 5. coastal marsh 6. mangrove swamp 7. coastal wetlands Freshwater 1.Lakes & Ponds 2.Flowing Streams 3.Inland wetlands

AQUATIC LIFE ZONES

Living in Water ADVANTAGES Buoyancy for support Limited fluctuations in temperature Nutrients are dissolved and easily available Wastes are diluted & dispersed LIMITING FACTORS Temperature Sunlight Dissolved Oxygen Nutrients These divide ALZ’s into layers: Surface, Middle Bottom Different Organisms will live different places!

I. MARINE ZONES The Ocean is divided into COASTAL zone & OPEN sea A. COASTAL ZONE – general information - warm, nutrient rich - land to continental shelf - covered at high tide, exposed at low tide - 10% of ocean area but 90% of species - connect with estuaries - protect land

COASTAL ZONES – specific types 1. ESTUARIES - where fresh & salt water meet - streams flow into ocean - lots of nutrients available - good breeding ground for organisms 2. COASTAL WETLAND - areas of coastal land covered for part or all of the year with salt water - bays, lagoons, salt flats, mud flats, salt marsh

COASTAL ZONE specifics 3. MANGROVE SWAMPS - warm tropical coasts with an over-abundance of silt (sediment & nutrients) - 55 species of salt-tolerant trees & shrubs - prevent coastal erosion; roots above water 4. SHORES - can be rocky or sandy (barrier)

5. CORAL REEF Found in shallow coastal zones of warm tropical & sub-tropical oceans Underwater populations of polyps (animals similar to jellyfish) that secrete limestone shells Most productive ALZ

B. OPEN SEA Divided into 3 zones, depending on the amount of sunlight EUPHOTIC BATHYAL ABYSSAL Very low avg. net primary productivity – (phytoplankton mostly) – 10% of ocean’s species Large gross primary productivity however – Simply because of total size

II. FRESHWATER ALZ’S A. FRESHWATER LAKES – general information Large, natural bodies of standing (still) freshwater Formed from ppt, runoff or groundwater that fills depressions in Earth’s surface Tend to have a lot of algal growth – No current to carry away or disperse Temp. is often high 3 types of lakes; 4 zones within a lake

3 TYPES OF LAKES 1.OLIGOTROPHIC LAKE (poorly nourished) Newly formed Very deep with steep banks Gravel, sandy, rocky bottoms Little shore vegetation, not much algae Crystal-blue or green in color Small pop.s of pp and small fish (trout & bass)

3 TYPES OF LAKES 2. EUTROPHIC LAKE (well-nourished) Aged lake Excessive nutrients, rapid decomposition Shallow, murky water from algae growth Sunlight can’t penetrate far, not many fish at the bottom Much vegetation

3 TYPES OF LAKES 3. MESOTROPHIC LAKES --In between Oligo & Eu - trophic

Lakes are divided into 4 Zones

4 LAKE ZONES 1.LITTORAL ZONE Shorelines & very shallow waters around edges. Most vegetation grows here 2. LIMNETIC ZONE Top layer of water Most organisms found here Highest temperature; sun easily penetrates

4 ZONES IN LAKE 3. PROFUNDAL ZONE Below the limnetic zone Less sunlight & nutrients Not many organisms found here 4. BENTHIC ZONE Very bottom layer of water, including bottom sediments Little, to no, organisms live there No sunlight penetrates

Lake Stratification – Seasons change temperature

B. FRESHWATER STREAMS Running water with currents Generally cold temps Usually clear, algae is quickly carried away Forms from surface water or runoff that does not soak into ground 3 zones

Freshwater Stream Zones 1.First (narrow) Zone Headwaters/mountain highland streams Beginning of the stream Water is very cold Many waterfalls/rapids Large amount of dissolved oxygen Cold water fish (trout) Algae & moss attach to rocks

Freshwater Stream Zones 2. Second Zone 1 st zone meets with other streams Slower current, warmer water Less obstacles (rocks, etc.) Mix of warm & cold water fish

Freshwater Stream Zones 3. Third Zone Streams join together to form a river Wide & murky High temperatures Low dissolved oxygen content Lots of sediment that deposits at end Carp & catfish

C. Inland Wetlands Lands covered with water all or part of the year (excluding streams, lakes, resevoirs) Examples include: 1. marshes (herbaceous plants) 2. prairie potholes (seasonal) 3. swamps (tress & shrubs) 4. mudflats 5. bogs