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ESTUARY AND FRESHWATER ECOSYSTEMS Dr. Nita Rukminasari

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Estuary and Freshwater Ecosystems

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POKOK BAHASAN

Estuary and Freshwater EcosystemsDr. Nita RukminasariSasaran pembelajaranMampu mengenali proses ekologi pada ekosistem estuariaMampu mengenali proses ekologi pada ekosistem air tawarKomponen nilaiKehadiran20%Tugas individu30%Tugas kelompok30%Final test20%

Tugas individuMembuat review artikel dari journal berbahasa inggrisTopik artikel bebas tapi harus berhubungan dengan materi kuliahTahun journal > 2000Review bisa menggunakan Bhs Indonesia atau Bhs InggrisTugas dikumpulkan sebelum final test 27 Desember 2012Tugas kelompokMembuat makalah dan mempresentasikan makalahTopik makalah:* Kelompok 1 kondisi lingkungan dan faktor pembatas pada ekosistem estuaria (06.12.2012)* Kelompok 2 struktur komunitas dan zonasi ekosistem estuaria (06.12.2012)* Kelompok 3 suksesi dan siklus nutrien di ekosistem estuaria (06.12.2012)* Kelompok 4 aliran nutrien dan jaringan makanan di ekosistem estuaria (06.12.2012)* Kelompok 5 Lingkungan, klasifikasi ekologi air tawar (13.12.2012)* Kelompok 6 biota air tawar dan komunitas lentik (13.12.2012)* Kelompok 7 komunitas lotik dan zonasi longitudinal serta aliran air (13.12.2012)Reference makalah minimal 6 journal internasional dengan tahun referensi > 2000Isi makalah 1) harus ada konsep/teori terkini yang berhubungan dengan topik makalah, 2) harus didukung oleh penelitian yang up to date (dari referensi journal yang di kutip), 3) membahas lebih mendalam tentang penerapan konsep dasar yang ada dan berhubungan dengan topik makalah, dan 4) harus menyajikan studi kasus/contoh kasus dari topik makalahPresentasi makalah bisa dalam bahasa Indonesia atau bahasa Inggris,power point dalam bahasa InggrisEkosistem EstuariaSasaran pembelajaran:Mampu mengenali proses ekologi pada ekosistem estuariaSubpokok bahasanDefinition and estuary characteristicsPhysical characteristics of estuaryClassification of estuaryAdaptation of estuarine organismsTipe of estuarine communityFood web of estuaryHow are estuary connected to us?Estuarine problems

What are estuaries?Estuaries arePartially enclosed bodies of water where freshwater from streams and rivers mix with saltwater from the ocean/seaTransition points from land to sea and from fresh to salt water.Tidally driven, but sheltered from the full force of the oceans wind and waves by reefs, barrier islands, sand, or mudflatsTransition zones between the marine-dominated systems of the ocean and the upland river systemsAmong the most biologically productive ecosystems on Earth

Picture of the Rio de la Plata http://en.wikipedia.org/wiki/Estuary

Where are estuaries?You can find an estuary anywhere a river goes into an ocean or sea.For example: Tallo River Estuary, Musi River Estuary, Florida Bay and The Great Bay.

Salt meets fresh

Freshwater is lighter than seawater and therefore flows above it forming a bottom layer of salt water called a salt wedgeNutrients carried in from salt wedge transform estuaries into very fertile areas for plant growth

Picture from www.narrabay.com/empact/waterQualityInfo.asp Basic Concepts: SaltsSalinitySalinity is the level of salts (mainly NaCl) dissolved in water. It is measured in parts per thousand (). Salinity affectsOsmosis for organismsStratification (formation of pycnocline)Salinity often varies longitudinally, horizontally, and vertically in estuaries.This can be a challenging environment for biota.

12Estuaries are scattered along the shores of all the oceans and vary widely in origin, type, and sizeThey may be called lagoons, sloughs, or bays such as Florida BaySome oceanographers classify enclosed seas with restricted circulation, such as the Baltic and Black seas, as estuariesOrigins And Types of Estuaries

Many estuaries were formed when sea level rose because of the melting of ice at the end of the last ice age (18,000 years ago)The sea invaded lowlands and river mouths in the processThese estuaries are called drowned river valleys or coastal plain estuariesThey are the most common type of estuaryOrigins And Types of EstuariesAnother type of estuary is the bar built estuaryThe accumulation of sediments along the coast builds up sand bars and barrier islands (found along coasts in the Gulf of Mexico)Other estuaries, such as San Francisco Bay in California, were created not because sea level rose but because the land sank tectonic estuariesFjords are estuaries where retreating glaciers cut deep, often spectacular, valleys along the coast. The valleys were partially submerged when sea level rose, and rivers flowed into themEstuary Landforms and Featuresbarrier beach a linear strip of beach that separates the ocean from marshes and other habitat behind it

bay an area of water bounded on three sides by land. Large bays are called gulfs.

17Estuary Landforms and Featuresbayou a small, slow-moving stream located in low-lying areas such as the Mississippi delta

cove a circular or round inlet with a narrow entrance or any sheltered bay

18Estuary Landforms and Featuresdelta a landform produced when a river flows into a larger body of water

harbor a place where ships may be sheltered, usually a very large cove, or manmade with breakwaters or sea wall

19Estuary Landforms and Featuresheadland an area of land surrounded by water on three sides

lagoon a body of shallow water separated from the ocean by sand bars or beaches

20Estuary Landforms and Featuresmangrove forest an assemblage of mangrove trees found in salty coastal habitats

peninsula a narrow piece of land surrounded on three sides by water

21Estuary Landforms and Featuresslough a swamp or shallow lake system, usually a backwater to a larger body of water

sound a large sea or ocean inlet larger than a bay

22Estuary Landforms and Featuressalt marsh a type of marsh that is a transitional zone between land and salty or brackish water

23Estuary Landforms and Featurestidal flats or mudflats areas of mud deposited by the tides, rivers, and oceans. Found within bays, bayous, lagoons, and other estuarine features.

24Physical Characteristics of EstuariesInfluenced by the tides and mixing of fresh and salt water, estuaries have a unique combination of physical and chemical characteristicsThese factors govern the lives of the organisms that live there.The salinity of estuaries fluctuates dramatically both from place to place and from time to timeSalinity varies with depth as wellSalt water being more dense sinks to the bottom and creates salt wedgesSalt wedges move back and forth with the daily tidesPhysical Characteristics of EstuariesUniqueCharacteristicsof theEstuaryEstuaries and coastal waters provide essential habitat for over 75% of the commercial fish catch and 80-90% of the recreational catch of fish.

Fish living in estuarine areas are especially interesting because they have to adapt to the different changes.

Such as the daily rise and fall of tides that creates water flow which distributes different amounts of food at different times of day.

Rainy weather or hurricanes can cause bay and delta waters to become fresher due to heavy flows of water from rivers and streams within the watershed, allowing fish such as largemouth bass, bream, crappie, and catfish to move downstream.

Estuaries are among the most productive natural systems on Earth due to the mixing of nutrients from land and sea.

Estuaries do a lot of cleansing. Mangrove leaves start to decay before they fall off the tree.

Living in EstuariesCoping with Salinity FluctuationsLiving in an estuary is not easy, so few species have adapted to these conditionsMaintaining the proper salt and water balance in cells and body fluids is one of the greatest challenges of organisms living in estuariesMost estuary organisms are marine organisms that can tolerate low salinity.Most estuary organisms are euryhaline species, that is, they tolerate a wide range of salinities.The relatively few stenohaline species, those that tolerate only a narrow range of salinities, are limited to the upper or lower ends of the estuary and rarely penetrate in the estuary properSome live in brackish water, or water of intermediate salinityLiving in EstuariesCoping with Salinity FluctuationsSoft-bodied estuarine animals, such as many molluscs and polychaete worms, often maintain osmotic balance simply by allowing their body fluids to change with the salinity of the water. These are called osmoconformers.Many fish, crabs, molluscs, and polychaete worms are instead osmoregulators. They keep the salt concentration of body fluids more or less the same regardless of the salinity of the water.When salinity of water is lower than that of their blood, they get rid of excess water and take-up solutes via active transport by the gills, kidneys, and other structuresAnadromous fish: migrate from sea to spawn in freshwaterCatadromous fish: migrate from fresh water to spawn in the seaLiving in EstuariesCoping with Salinity Fluctuations

Types of Estuarine CommunitiesSeveral distinct communities are associated with estuariesOne consists of the plankton, fishes, and other open water organisms that come in and leave with the tideSeveral other communities are permanent parts of the ecosystemOpen WaterMudflatsSalt MarshesMangrove ForestsTypes of Estuarine CommunitiesOne of the reasons many of the worlds great cities developed around estuaries is the rich supply of fish and shellfish in or near estuariesMany species of commercially important fishes and shrimps use estuaries as nurseriesTypes of Estuarine Communities:Open WaterThe bottoms of estuaries that became exposed during low tide often form mudflatsOrganisms exposed to desiccation, wide variations in temperature, predation, and variations in salinity.Bacteria are abundant in mudflats as decomposers of organic matter.Chemosynthetic bacteria (hydrogen sulfide)Infauna: Dominant animals in mudflats that burrowEpifauna: aniamls that live on the surface or as sessil formsThese include detritivores, deposit, suspension, and filter feedersTypes of Estuarine Communities:MudflatsEstuaries in temperate and subtropic regions are usually bordered by extensive grassy areas that extend inland from the mudflatsSometimes they are grouped with coastal environments flooded at high tide and with freshwater marshes and collectively called wetlandsTypes of Estuarine Communities:Salt MarshesSalt Marsh and Mudflat

Some Inhabitants of mud flats

Mangrove forests (mangals) are not limited to estuaries, but in some ways they are the tropical equivalents of salt marshes, though the two coexist in many placesMangroves are flowering land plants adapted to live in the intertidal75% of all sheltered tropical shores were at one time fringed with mangrovesMangrove forests, however, are being rapidly destroyed by humansTypes of Estuarine Communities:Mangrove Forests

Residents of EstuariesMany bivalves, such as oysters (above), and mussels (below), inhabit estuaries.

47Add labels for picturesBlue crabs are harvested to eat.

Diamondback terrapins are the only turtle that lives in brackish water.

48Killifish thrive in estuaries. Alewives live in salt water but move through estuaries and into rivers to spawn. They are a favorite prey species for salmon and many other predators.

49Coho salmon migrate up rivers to spawn each year, returning to the area they were spawned.Great blue herons feed on fish and amphibians living in estuaries.

50Food Web of the EstuaryHow do plants and animals of the estuary get the energy they need to move and grow?Green plants can change sunlight energy into food (chemical) energy. The sun is the source of energy for all living things.

Producers make their own food using energy from sunlight. This is called photosynthesis.

algaeeelgrassMicroscopicphytoplankton

carbondioxidewaterSunlightenergysugarAnimals get energy from eating plants or other animals. They are called consumers. Primary consumers (herbivores) eat plants.Secondary consumers (carnivores) eat other animals.

Omnivores eat both plants and animals!

Energy is transferred from plants to animals through Food Chains.

Sunlightenergy

Phytoplankton are floating microscopic plants. They are very important estuary producers.Phytoplankton are eaten by floating animals, zooplankton - and by bigger animals like snails, clams, and barnacles.PhytoplanktonZooplanktonSmall but Mighty

Plants and animals:Burn energy when they move and grow.Store energy in their bodies.Release unused energy as waste and heat.food energy inUndigested food energy outEnergy used for swimmingFood energy stored in fish - ready to be eaten

In an estuary, not every animal or plant gets eaten. Plants like eelgrass die back each year, just like the grass in a field. This stored-up energy is still important.

When a plant or animal dies, it rots. Bacteria breaks down the stored energy into food that can be used by other animals. Detritus: dead and rotting bits of plants and animals

Detritivore: an animal that eats detritus.

Estuary food chains often overlap, making food webs.

Relative Importance Of Food Web LinkagesPrimary (75-100% of Total)Secondary (50-74% of Total)Tertiary (25-49% of Total)Incidental (0-24% of Total)PacificStaghornSculpinGreat BlueHeronPenpointGunnelSharpnoseSculpinSmall Fish (inc.herring, perch)BuffaloSculpinChumSalmon (juv.)TubenosePoacherMysidsGammaridAmphipodsDetritusCumaceansPaddedSculpinTunicatesStarryFlounder (juv.)Sanderlings,Long & Short-billedDowitchers, Greater YellowlegsSaddlebackGunnelBenthicMeiofaunaHippolytid, Crangonid,And PenaeidShrimpPolychaeteAnnelidsGastropodMolluscsSaltmarshPlants & EelgrassPhytoplanktonMicrophyticAlgaeWhimbrel, Mallard, Northern Shoveler, Pintail, Western SandpiperEnglishSole (juv.)CrescentGunnelNemerteansTidepoolSculpinShinerPerchBrachyuranCrabsHarpacticoidCopepodsSnakePricklebackGastropodMolluscsAnthozoansBivalveMolluscsSnow Goose, Canada Goose, black Brant, American cootFlabelliferanIsopodsMacrophyticAlgaeSilverspottedSculpinTanaidsBayPipefishValviferanIsopodsFrom Simenstad et al. 1979Because many animals eat more than one thing, tracing energy through the estuary can get messy.How are Estuaries Connected to Us?Commercial Economic BenefitsRecreational BenefitsCultural ImportanceEnvironmental BenefitsCommercial Economic BenefitsFancy steamed shrimp or fried catfish for dinner?Estuaries provide habitat for over 75% of commercial sea catch.Estuaries support jobs and income for many people each year.Many estuaries are important centers of transportation and international commerce.Jobs and income - Shrimp trawlersCrabbersCommercial fishing boatsFertilizer production from crushed oyster and clamsPharmaceutical

Recreational BenefitsFishingBoatingBird-watchingHiking and campingVisiting the beachSight seeingBotanical studiesEco-tourismEstuaries provide a place for families and friends to enjoy their hobbies and spend time together in unique and beautiful areas. And, these activities, often called eco-tourism, support local economies near estuaries. Fisherman buy fresh bait, tackle and food. Boaters pay marina fees and hotel fees. Tourists eat in local restaurants and buy local goods.Cultural ImportanceOften city and trade centersImportant source of foodBuffer communities from storm surges

Often city and trade centers To many communities, estuaries are rivers of life.Important source of food U.S. consumers spent an estimated $69.5 billion on fishery food products.Buffer communities from storm surges Salt marsh soils and grasses buffer floods, absorb excess water and slow down storm surges.Long history of cultural use by Native Americans Many Native Americans historically, and still today, rely on estuaries for their way of life. Historically, tribes traded shells (wampum) as currency. They used shells as gifts, decoration, tools, and spearheads. Clay was used for making pottery. Present day tribes still rely on fishing and shellfish for food and income.

Environmental BenefitsProvide critical habitat for many speciesBirds, fish, amphibians, insects, and other wildlife depend on estuaries to live, feed, nest, and reproduceProvide stopovers for migratory birds species

Some organisms, like oysters, make estuaries their permanent home; others, like horseshoe crabs, use them to complete only part of their life cycle. Many fish, including American shad, Atlantic menhaden and striped bass, spend most of their lives in the ocean, but return to the brackish waters of estuaries to spawn.Why are estuaries Important?Ecosystem ServicesWater filtrationHabitat protectionEcosystem services are difficult to put a value on; they are essentially priceless.

Ecosystem services are fundamental life-support processes upon which all organisms depend. What Role do Estuaries Play in Earths Cycle?Nutrient CycleElements are recycled and made available to living organisms.Water CycleEvaporation occurs, and also serve to recharge groundwater.Cycle of LifeEstuaries provide shelter, food and nursery grounds for animals.The Constantly Changing EstuaryTides create cyclical changesTidal ZonesSupratidal Zones Area above the high tide water line that extends upland.Intertidal ZoneArea that is exposed to the air at low tide and submerged at high tide.Subtidal ZoneArea below the low tide water line.Water Depth and Estuary LocationWeather, Seasons and Climate create changeTides are necessary for healthy estuaries as they flush the systems and provide nutrients to keep the food webs functional. However, tides creat constantly changing conditions of exposure to air and inundation to water.Tidal ZonesSupratidal Zones Area above the high tide water line that extends upland.Organisms in this zone: various trees, and shrubs, mammals such as deer and fox, birds, reptiles and much more.Intertidal ZoneArea that is exposed to the air at low tide and submerged at high tide.Organisms in this zone: shore birds, marsh grasses, shrimp and fish, snails, mussels and oysters, burrowing worms and much more.Subtidal ZoneArea below the low tide water line.Organisms in the zone: eel grass, algae, fish, starfish, shrimp, crabs, dolphins and much more.

Water depth - Shallow estuarine waters allow great temperature changes. The sun heats up the estuary during the day, and cool waters from rivers and seas enter the estuary by night. Tides affect temperatures. At high tide, the deeper, lower reaches of the estuary remain cool, and only the top layers are heated by the sun.

Weather patterns, seasonal cycles and climate change affect and change conditions in estuaries such as structure, temperature and water quantity and quality.

Estuarine HabitatsCommon Estuarine HabitatsWater ColumnOyster ReefsCoral ReefsKelp and Other MacroalgaeRock Shores and BottomsSoft Shores and BottomsSubmerged Aquatic VegetationDeepwater Swamps and Riverine ForestsSalt Marshes (Coastal Marshes)Mangrove ForestsA rich array of habitats surrounds estuaries. The type of habitat is usually determined by the local geology and climate.

Common estuarine habitats include (listed on slide).

You can find nearly every type of estuarine habitat along the coastline of the U.S.Natural Disturbances to EstuariesWindWavesTidal currentsIceWind blows across water, waves are formed. Waves carry energy and help stir up and mix nutrients, silt and decaying matter in an estuary.

Ice forms, wind blows the ice rafts scourging the banks.Anthropogenic or Human Disturbances to EstuariesCoastal DevelopmentToxic SubstancesNutrient Pollution EutrophicationPathogensNon-native Species and Invasive SpeciesOver fishingDredging and fillingDamsGlobal Climate ChangeCoastal Land UseHuman Impact on Estuarine CommunitiesThe environmental consequences of human intrusion in estuarine communities, particularly in highly productive salt marshes and mangrove forests, have been disastrousAll around the world estuaries are being dredged to make marinas, artificial harbors, and seaportsOthers are filled to create everything from industrial parks and urban development to garbage dumpsDredging navigational channels increases the exposure to wave action and therefore the destruction of salt marshesSimilar affects are being and have been felt by mangrove forestsThere is evidence that the 2004 tsunami would have been less severe in some areas if the mangroves would have still been present.Mangrove forests also help with shoreline erosion and protects against storm surges generated by hurricanes.ANY QUESTIONS?