good day everyone um previously we have discussed the aquatic environment wherein we talked more about the water cycle the hierarchical classifications of the aquatic environment particularly majorly classified as the oceans or the marine environment and the freshwater environment and we also learned that the marine environment deals with the study of oceanograph oceanography the study of seas and oceans and the freshwater environment deals with the study of limnology or rheology deals with the study of rivers and lakes and further we also discussed that the limnology is classified further into a logic atlantic environment now today we will be talking more about the aquatic environment focusing on the freshwater ecology so this module will teach you on the fundamentals of freshwater ecology so the science of limnology including the low tech lotic atlantic series although we have already tackled uh some of these fundamentals or concepts of the lotic and lentic series we will also be discussing the types and origin of lakes and also the limiting factors in the freshwater environment as well as the different types of stratification and the corresponding types of organisms in each layer of these stratifications and so therefore at the end of this study you are expected to discuss the importance of fresh water environment explain the lottic and lentic series distinguish the different types of lakes identify the limiting factors in the freshwater ecosystem as well as explain the context of thermal certification and also describe the donations of the lake characterize the different organisms in the freshwater ecosystems and also you're going to classify new stones from plankton's necktones and benthos okay so those will be the major concepts that you will be focusing on on this module and so um before anything else so as a form of introduction uh here we have the module for the module 3 of course the freshwater ecology now since we are talking about freshwater ecology we must first learn what are the fundamental backgrounds or fin principles with regards to the composition of the freshwater ecosystems so here we have it is said that only three percent of the world's water is fresh so all of the 97 percent is marine water so only three percent of the world's water is fresh water and 99 of the three percent of this is either frozen in glaciers and packed in ice or buried in aquifers so just imagine that 99 of the three percent of the total world's water in the earth's surface is frozen in glaciers packed eyes or buried in aquifers so that's a major amount of the fresh water distribution so the remainder of this is found in the lakes ponds rivers and streams so only one percent of the three percent are the waters that came from lakes samongapans sa rivers and streams so just imagine how scarce are these uh resources are and they play a very significant um role in the aquatic environment now if you take a look at the distribution of this water or what we call as the quick view of the planetary freshwater availability we can see in this figure that most of the fresh water no this is the scale basically the pink ones are the areas which has a very scarce fresh water supply while the blue ones are the most abundant part of the globe we're in it has a very abundant fresh water supply so where where are the areas that has a very much abundant supply of fresh water the areas such as the northern america the eastern the western pacific pacific coast of south america and some regions of australia and northern this is africa so most of the areas in this this area in this uh equator part are are basically scars in its cars and scar scars in water supply fresh water supply as you might have noticed most of the deserts on subject methodology you will understand why the deserts are commonly found in these regions and so therefore that comes that that basically has something to do with the coriolis force and the rotational uh planetary rotation and so on and so forth okay so that is the distribution of the fresh water supply in the world now um why are we dealing with the fresh water because fresh water are the most convenient and the cheapest source of water for domestic and industrial needs no we all know for a fact that we don't have supply the industry the domestic areas the commercial centers with the marine water no well let me get another supply of marine waters into the the malls and the hotels restaurants and so on so forth the urban areas we supply them with fresh water so that is the most convenient and the cheapest source of water and fresh water and secondly the freshwater components are the bottleneck in the hydrologic cycle we are know for a fact that fresh water are basically or fresh water environments plays a very important role in transferring uh the waters in the faces of the water cycle right so from the lakes down to the seas with the channel from the rivers streams and uh some other channels and from the seas up to the sky for evaporation and and and so on so forth okay so basically fresh water plays a very important role in the ecological concepts thirdly freshwater ecosystem provide the more convenient and cheapest waste disposal system so basically this are the three of them the major importance of the freshwater uh supplies in in the world now since we're dealing with the freshwater we will be focusing more about limnology now what is limnology limnology basically means that you're studying freshwater ecosystems no with an emphasis of understanding the physical chemical and biological processes that are basically important in structuring and maintaining the water or the fresh water systems so we do not just name environments here we are not just identify the organisms there but we must understand the physical processes the chemical processes as well as the biological processes which are all of these three are very important in structuring and maintaining the stability of the fresh water systems like lakes rivers bugs marshes swamps so those areas are very important so we must understand the physical chemical and biological processes and that's the reason why we will be talking more about the organisms the stratification of the lakes the relationship between the light penetration of the sun towards the temperature of the water and the organisms that live there in in each of the stratifications or is each of the layers of the water so um basically limnology embraces the three major areas the atlantic waters which compose of the lakes and any of anybody of water that is not moving the lottic waters which are the moving waters the rivers the streams and also we will be covering as well the estuaries so it embraces these three disciplines or these three areas and study of fresh water environments okay so although previously we have already tackled the the word lentic the logic and so on and so forth so this is just a quick overview or a review on the concepts of lentic and lotic environment so we all know for a fact that lentic comes from the derived derived from the latin term which is lentus meaning to say sluggish no in some reference it says uh it came from the word lennis which means calm no non-moving refers to all form of inland bodies of water which the water is essentially static static meaning to say it is not moving so uh there is also a genetic sequence of these units that make up this series so there is what we call as the succession right so succession meaning to say from this type of body water to the other uh type of body of water and to to the next type of body of water as long as it is still atlantic environment meaning to say a non-moving environment so there is what we call a succession so succession atlantic series goes toward the extinction with age what do we mean by that uh extension we age basically meaning to say uh from the through time after decades centuries and millions of years there will come a time that that will turn into only a pun no later on we will um we will differentiate what what's the difference between lake and ponds so that that basically drives a certain aquatic environment to grow old no so manga indications and similar factors that turns into that type of environment into another type of environment so puns could also grow into another type of lentic environment it will turn into swamps in a very long period of time no so this is the succession from lake to pants to swamp because of the different factors that contributes to the succession okay so here we have the the definition of the word lakes ponds and swamps lakes are larger bodies of water occupying distinctive basin basins so basically larger among lakes and are still non-moving no statixella puns however are generally suggest small quiet bodies of standing water usually shallow enough to permit the growth of rooted plants from one shore to the other so unlike lakes and lakes national transition growing among plants in between throughout bottom or water surface i mean bottom surface say ampina plants so ponds enable the growth of aquatic plants in all areas of the bottom bottom areas however among the swamps are a wet low land which supports the mosses the shrub together with relatively large trees now there is also what we call as the marshes marsh and the difference between marsh and swamps so basically the swamps uh permits the growth of large trees major plants shrubs and mosses lower forms of plants like unlike the swamps that permits the growth of large trees among major forms of trees or plants okay so those are the definitions of the three including the definition of the mars and uh here we have so as i have said earlier there are factors that causes the succession of atlantic series aquatic environment will grow old from pond to i mean from lake to ponds from pods to swamps so these are the three major causes of the succession in the lentix series so once again atlantic or environments or aquatic environment that are static okay so first is of course the gradual feeling of lake basins so we'll know for a fact that lakes ponds and swamps are the catchments of rivers water so the continuous deposition of accumulation of sediments and other materials into the lake basin so there will come a time say for example uh materials that because of the gradual feeling in the lake basins in the pan basins and so on so forth so monash is a factor why there are successions secondly the catastrophic events so examples of catastrophes that may destroy the lake basins are a great flood that will destroy the lava dam which produces the lake an earthquake which may remove the basin through uplifting of land surface so there are catastrophic events kanama techno tectonic movements flood and lava so kana silang events basically will cause a succession in the atlantic series okay thirdly are the loss of water so the loss of water lake often become extinct extinct because their water is drained away such such as when the outlet stream erodes its valley below the level of the lake floor a change in this climate may also cause the lake to lose water like for example there is a lake in somewhere in the middle east that uh dry out because of irrigation for farming cottons i think if i'm not mistaken it was rlc no if you have time you can search for the history of rlc what happened to rlc why it turns into a dry lake and on a dry lake when an rlc so basically there are there are agricultural concerns that basically uh diverts the water from the rlc to the farmlands of cotton farms so there are further details on that one in the internet available no indirectly search one of my time and uh what are since since the third factor is the losses of water no and third factor in the cause of succession atlantic series is the loss of water so what are the factors or how is the water being lost in that particular aquatic ecosystem so first the outflow surface streams in drainage lakes so on my lakes i'm gonna say outflow manga outlet okay so that will be a water loss for them another is seepage into groundwater through the bottom of the lake in seapage lakes so just imagine gonai manga uh vacant undergrounds below that lake there will come a time that this lake no absorbed and will be deposited on that particular underground we we will term them as aquifers the dion okay so those that is a second factor another is evaporation from the water surface which has with contributes to a biggest loss in the water loss among lakes so on evaporation especially when when the lake is exposed to a very very um prolonged period of sunlight now past pasca evaporation except among lakes that are found in the uh temperate areas wherein lakes well will mostly be covered with ice because of the cold environments another is the transition by aquatic macrophytes and the surface so transpiration basically is previously we have already defined what is evaporation how it differs from the transpiration so transpiration basically is the risk release of water molecules from aquatic macrophy i mean aquatic plants okay so here in this example among lentic environments the transpiration occur in aquatic macrophytes so like for example the water lilies and some other minor aquatic plants living in or thriving in that particular atlantic environment may be either ponds or lakes or emerging from the surface like bull rushes and cattails so transpiration is the fourth factor while there are losses of water from lakes ponds and swamps and marshes okay so those are the four factors that causes the water loss in the lakes so let's proceed now to the lottic solotic or the running water series lotic came from the latin word lautus meaning to say to wash so since washing machia it is moving right so moving and young water and burns what are what are the types of aquatic environment that are considered aslothic so these are revelate uh brook creek um streams and rivers so these are the four factors no i mean some of the types of the lotic environments or lotic aquatic environments so loctic refers to all inland bodies of water in which the entire body of water moves continuously in a defined direction so there is really a direction there is really a catchment area for this logic environment so like lentic lotic environments also have a genetic sequence to the units that make up the series so reveal it to the brew down to the creek and down to the streams or rivers so the hot the the lower it gets no from the watersheds from the high mountains the lower each gets the wider the lotic environment it will be no so from rivulet this is basically a very narrow body of water down to the brooks down to the creeks down to the streams and forming into rivers when the streams combine with the other streams so this is the succession of lotus series goes towards as well with the extension extend extension with time okay so must see or older i mean okay so basically this is the context of the logic environment with regards to the succession now uh if you take a look at the the age of the lotic series since we're talking about succession a river's age is based on the extent to which it has a cut or to to which it has cut its valley towards its base level now what is base level if you can see this figure no can configure the day this is this basically illustrates the base level okay so when we define the base level it is the level of the body of water in which the water flow that is the sea level or the level of the receiving leg so this is where uh on base level in our vernacular term a level and water mock-up mufflopa in that particular area say for example if the water is already here would it would you think that it will still flow down to the sea level no so meaning to say it is below the base level so if it is below the base level it is older however higher pashadri area like for example a freshwater environment are located here salee or sadly somewhere so since it is still above the sea level um lotic environment so there are also cases that you could you could uh adjust your your um your base or local base level based on the um nearest atlantic environment like for example here in this one angle swang lake is the local base level so you you identify the lotic age or lotic environment age with respect to the local base level which is the lake so if it is already on the same level with the local base level it is already an old logic environment okay so i i hope that's clear and here we have uh the rivers and streams can be divided along with the three dimensions so you can divide the rivers and streams into according to length according to with and according to vertical classification okay so first off is the length so we have what we call as the pulls the runs the rifles and the wrappings so you can you could observe that rivers mostly flowing rifles basic basically is faster and young rates are current and rapids basically water rafting activities so that is according to the length classification of rivers and streams another classification is according to with either it is wetted or active channels so there are areas that are considered as non-flowing solana daily flow because this this areas are basically mostly connected with the river banks and active channels flowing in japan and then uh vertically you could also classify the rivers vertically as the water surface and the water column there are organisms thriving in this uh two classifications of flavors and shrimps and here we have also the term ripe riparian zone it is a transition area between the aquatic and upland terrestrial environments so you can search more about riparian zone and how important these zones are with regards to the food chain the food web and how organisms rely on this particular zones okay so more about lotic series so there there are two major zones of lotic series first zone is the rapid zone so rapid zone or shallow water where velocity of the current is great enough to keep the bottom clear of silt and other loose materials that's providing a firm substrate so kidney among areas are flowing national rapids so so fermanyan substrate more or less composed of mangastones and so on so forth and in contrast we have the pull zone which is deeper water where velocity is reduced and the silt and other loose materials tend to settle at the bottom thus providing a soft bottom unfavorable to surface benthos but a favorable for borrowing form forms nectars and some cases so uh rich lotic series no rich rich diverse no organic i mean organisms diverse environment are located in the pool zone because most of the organisms could thrive and most of the nutrients and minerals and foods and uh shelters are basically located in these zones on pool zone and uh here we have since we were talking about the age so we must not forget what are the reasons that basically causes the characteristic of the succession in the atlantic series so succession meaning to say change from the aquatic environment okay so first off is the mechanical erosion from the word mechanical erosion meaning to say running water mechanically erodes the land by abrasion the grinding contact of the builders the rock fragments and the sediments it rolls or carries the suspension against the material from the substrate so basically on uh that is caused by mechanical erosion grinding contact of builders and drug fragments secondly through chemical erosion rocks and are that are resistant operation are worn down through chemical erosion running water dissolves the care and carries away the soluble minerals in the soil and rocks it encounters along its path so there are there are cases kasagara manga falls are [Music] because water does not only carries water there are also chemicals on those water coming from the upper upper zones of the rivers may it be either from agricultural lands or some water sheds or agroforestry agroforestry lands okay so that is second so basically those are the factors that causes the characteristic succession in lentix series the mechanical erosion and chemical erosion now let's proceed since we we're talking about uh earlier we're talking about lentic environments we must understand first what are the origins no origins of these atlantic environments what are the regions of the lake how does the lake uh formed through time or through uh catastrophic events so first most lakes are created by catastrophic events of glacial volcanic or tectonic activity because of their origins lakes tend to be aggregated into distincts in temperature and subarctic regions of the northern hemisphere secondly most lakes are small or uh are off glacial origin so kasagara manga lakes say the the the breakage of the ice particularly in in the northern hemisphere and the southern hemisphere the polar regions and the date from the pliostosin approach of the quaternary period so meaning to say these are these are the factors these are the second causes or second um factor that that basically originates a lake no nano among the lakes particularly in the upper hemisphere and the lower hemisphere third great lakes of north america represent the largest mass of fresh water on on earth and lake superior has the largest surface area of any purely freshwater lake so these are basically the major lakes that are located or that are found in the world no on great lakes uh north america organ lake superior and great lake is the largest mass of fresh water in earth however and lake superior is the largest surface area and likes a great lake and then fourth is lake baikal contains about 20 of the total volume of surface fresh water and it's also the deepest known lake with a maximum depth of 1620 meters so lake basically um does not this kind of lake basically does not permit the growth of aquatic plants at the bottom because the light penetration do not at the light from the sun do not penetrate at this depth already among a thousand matters daily novel but online and then there are types of lake first type is tectonic lakes which are formed by movements of earth's crust so tanaan lake like some movement of earth's crust are called as tectonic lakes secondly volcanic lakes small depressions in craters explosive origins resulting from lava coming out into contact with groundwater or the gassing of magma we also termed them as caldera for volcanic lakes formed by collapse of roof of partial empty magma chamber so those are volcanic lakes we have a volcanic lakes here in the philippines like the lake taal right third third type is glacial lakes most common lake origin due to the illusion and the position associated with glacial ice movements so because of sometimes the global warming perhaps so nayamanga lake is going to form because of the movements of the large large blocks of ice in the polar regions and another is landslide lakes lakes formed by rock slides and mudslides so those those are landslide lakes fifth type is solution lakes formed by shallow desolving of the soluble rocks by water most form in areas with limestone bedrock okay so solution lakes third is fluvia lakes formed by river activity you know river activities like floods and so on and so forth malformed lakes by the rivers and then here we have another type julian lakes formed by the wind activity in ariad regions forming june lakes generally temporary lakes lanzila another shoreline lakes created by at irregularities or indentions along the coastline of large lakes usually result of longshore currents depositing materials so name on a leak small form because of minerals and uh substrates and saltations coming from the coast areas or coastal areas organic lakes are vegetation and animal like manga caused by beaver dams no beaver dams shelter environment because of this um vegetation or animal nana build a shelter number 10 is anthropogenic lakes dumps and excavations by humans okay so obviously 11 meteorite lakes crater from meteorite impacts so those are the different types of lakes you know classic classic among lakes now uh i have also there one task perhaps anyhow your you will be required to identify the type of lake top 10 lakes of the philippines at philippines followed by a lake and then lake maine and then lake nauhan so those five lakes identified the type of lakes each of them monsanto classi and laguna de valencia okay so next up are the limiting factors in freshwater ecosystem so the major or the very common limiting factor among aquatic ecosystem is the temperature so temperature plays a very important role in the diversity of the aquatic environment so since we're talking about temperature we must not forget the properties the thermal properties of water first property of water with regards to temperature is the high specific heat no a relatively high amount of heat is involved in changing the water temperature so one gram calorie of heat is required to raise one milliliter of one or one gram of water one degree into one degree centigrade so this this is the property of water where uh organisms are allowed to adopt or acclimatize in the very very sunny day you know congratula high on sunlight in that particular atlantic environment like for example it's a colleague i mean exposed sunlight and lake dilling because of this high specific heat there is a necessary or there is a given time that this particular water could turn into a into a uh uh in it among water so it will give a time to the organisms also to adopt in the changing temperature of the lentic environment okay so that's first second property is the latent heat of fusion the amount of heat energy required to change one gram of ice into at zero degree celsius into water or liquid water at zero degrees celsius no even though not change in temperature mug chains of face and water because of this property you know will not change any young temperature pyramid chains and face from ice to water okay so the thermal process involved is known as melting and it requires 80 calories of heat per gram so basically it does not change the temperature but change the face of the mater or the water itself third is the lat this is in continuation the same quantity of heat is given off to change one gram of liquid water at zero degree celsius twice at the same temperature during the process called freezing in the freezing decants uh liquid it turns into ice at constant temperature it is called as freezing that is because of the property called latin or high latent heat of fusion third property in relation to temperature is the highest known latent heat of evaporation this is basically the heat required to change one gram of liquid water at 100 degree celsius into a steam at 100 degrees celsius this thermal process is called boiling or evaporation and it requires 540 calories of heat in order for this reaction to occur okay so the same amount of heat is released in the reverse process called condensation so basically these are the three major properties of water that temperature becomes very important as a limiting factor in the freshwater ecosystem okay so that is uh the factors that needs to be considered when we understand the physical relationships of the the physical non-living environments towards the living environment found in the aquatic ecosystems now if you take a look at the physical profile of the temperature with regards to the thermal stratification we have here the different layers now when we say stratification it means to say the layering when we say thermal we need to say the temperature so thermal stratification means the layering temperature of the lake no so we have here the prelimion the warm water the thermocline the rapid temperature change this is a very rapid temperature change areas this is a very cruci uh daily stable areas today cold water is the high pollen hypolimian layer no so if we take a look at the thermal profile on that one no this is in relation to the depth and the temperature so the the shallower the area the higher the temperature it is the deeper it gets the colder the temperature of the layer of lake it gets also so the areas here are basically the thermocline this is where the rapid temperature change occur thermocline is the middle portion where the rate of temperature change is the greatest depending on the light exposure from the sun depending on the water circulation depending on the vegetation also okay so those are the three classifications or the thermal stratifications of the lake now let's proceed to the thermal certifications among the lakes found in the uh temperate regions in the temperate regions they donated spring over turn or mixing this is where the sun hits the water surface the wind steers the warm water which is less dense down to the depth when the turbulence eventually dissipates this depth becomes the top thermocline so munichang period we're in on water exchange of nutrients from the bottom towards the top okay so this is called as the spring overturn second is summer stratification this is uh this happens once spring thermocline is established it is thermodynamic thermodynamically stable and can be destroyed only by cooling of the epilympian region okay so cool region this is basically what will happen and uh the salt oxygen cannot be replenished except by diffusion from lithium neon which is very low no once a lake is stratified direct heating is all important source of heat to the preliminion region so basically uh among a phenomenon will occur once a year in nisha okay so summer stratification now where are we so those are the two two major events that occur among the lakes found in the tropical regions no the third one is the fall overturn this is a phenomenon in the fall less uh in the fall less solarization reaches the lake surface during the day and lee heat losses are greater at night cooling what cooling water is denser than warm water below so it sinks forcing warm water up to the surface this convective current in the wind mixing between the weakened thermocline so this is where uh the the mixing occurs also so i have here uh in the next slide i will be showing you how this cycle occur throughout the year okay so the fourth uh the fourth phenomenon among the the cycle of lake with regards to the with regards to the layers and the availability of nutrients found in each layer and how these nutrients are being transported from the deep bottom to the upper surface in order for this nutrients to be available for organisms to consume or to grow among uh plants so because most of these nutrients are the primary limiting factor among aquatic plants among aquatic plants absorb nutrients or sometimes upper surface and that's the reason why they need the nutrients coming from the below so full of return is where the mixing happens so another one is the winter stagnation after the fall of return the lake is homo thermos and mixed up to the bottom this mixing continues until the surface freezes ice covers prevents mixing by winds freezing occurs when the surface water reaches zero degrees celsius in the wind less cold at night so basically that's the reason why kasagarang that is because of the process called winter stagnation no cold water environment our cold water environment are less dense so what happens to the less dense water it will float no more now since the the upper surface is uh cold no fermentation in a blow so hung in a cold an environment near cold and then at the same time less than spasha there will come a time that that particular uh upper surface will freeze unaffecting the bottom bottom uh layers of the lake song bubble wrang mug freeze okay less dense motion and dissipate and then turns into ice sky colder man upper surfaces now here is the illustration on that uh that uh faces that we were talking about earlier this is a win the winter all of the water are basically cold the spring turnover we're in the nutrients from from bottom will be circulated throughout the layers of the lake so basically this is the turn spring turnover and then the early summer so since there will now be be a sun an upper epileptian layer will turn warm no a warming young environment this upper and then the late summer a higher layers will cover the warm water guy from international exposed to sun even though on uh a hypolimian will stay cold environment so early fall must asp uncovered warm water and then there will be a full turnover wherein the the nutrients will again be mixed and there is what we call as the upwelling you know upwelling a process occurs during this fall turnover and then go back with the cold environment during winter okay so basically that is the the cycle of the physical uh temperature profile of the layers of the lake among the lakes in the temperate regions now another limiting factor in the lake are the lights no lights lying donation and legs because of the importance of light for the photosynthesis and respiration it imposes a structure in the legs both vertically and horizontally okay so there is what we call as the photic zone and the apothic zone photic or euphotic that is synonymous the photic zone extends from the surface depth where light is one percent of the incident light at surface okay so one percent light and young incidents are an incident light at the surface sunlight penetration regardless that is the photic zone so environment more or less and sometimes this this um turbidity are derived from the diversity of organisms found in the particular aquatic aquatic environment now um on a photic zone is basically uh areas which extends from the bottom of the photic zone to the bottom of the lake so cleaning a classification satellite is basically duhallang classic classification and classification i mean unzonations a lake with regard with respect to temperature is too low epilion a thermocline or profandal and kinning's donations of the lake with respect to light is composed only of two zones the photic zone and apothic zone so on a photic zone you can subpoena the bottom apart supporting zone towards the bottom uh part of the lake is the floating zone more or less skinning among areas do not observe photosynthesis well at night photosynthesis or naive photosynthesis feel very low because light penetration or the light from the sun does not penetrate on these layers so they rely or most activities that occur in this legions are respiration so respiration meaning to say dragon organisms less food for them okay so photic zone basically the photosynthesis and and respiration ratio is less than one and photic zone basically the photosynthesis and respiration ratio is greater than one we also have the term compensation depth we're in the photosynthesis and respiration is equal to one that is equivalent to the thermocline when we talk about the uh thermal stratification of the lake okay now uh here we have the comparison between lakes and the serbwas what's the difference between lakes and reservoir lakes are natural no naturally occurring nagination naturally and reservoirs are man-made artificial integration with regards uh to to build uh some sort of atlantic environment okay now if you take a look at the donations of the lake with regards to the um light penetration this is what i was talking about no killing photic zone photic zone basically allows the growth of aquatic plants because aquatic plants could process photosynthesis with the presence of sunlight drinking ammonia regions and below supporting zone are a photic zone or in in the term from from the thermal certification is the profandal zone so kinemazones are colder and do not have light and so therefore the photosynthesis and respiration is basically less than one most of the activities that occur in these regions are decomposition decomposing organisms bacteria fungi and some other decomposers are found in the substrate of these regions so um [Music] is basically uh the area where most uh literal zone basically allows the growth of aquatic plants now there are some areas aquatic plants monolitheral zone zone basically is the area more or less marine environment 200 matters below and then to the uh onwards ocean wards buenos aires zone zone however is the colder environment which has no sunlight light penetration underneath saprofandal or aquatic zone okay so i hope uh this illustration gives you um an idea on how does the lake are classified with regards to the donations now uh here we have again the literal zone extends from the shore to just above the influence of the wave to a depth where light is barely sufficient for rooted aquatic plants to grow so again as i have said literal zone katong areas okay so lemnetic zone is again uh area beyond the influence of the shore bottom or pelagic are basically um areas that has not enough light where uh not enough light that reaches that supports the productivity or the photosynthesis so you can even area among the light or light light penetration and so therefore photosynthesis will occur so this is the vandal zone luminetic zone and lateral zone i hope that's clear now if you take a look at the water circulation since we were talking about the layering and how does this nutrients will be available for aquatic plants to grow because most of these plants will will suffer from the limiting nutrients no internet relies on nutrients in this layer daily uh sufficient because of the water circulation all the nutrients from from uh all throughout the lake will be distributed among nutrients will be distributed to the upper surface okay so what are the factors that causes this distribution or circulation partly because of the wind no wind blows a water surface that will also drives the water surface to circulate also and the surface tension of the water here and evaporation will occur also here and this is true to the to the temperate lakes no lakes in the temperate regions where most of the lakes are covered with ice zero degrees celsius and will become less dense it will float in the the surface and then turn into a solid in the form of ice and the wave of action there and the circulation from the preliminion so this is the epileptian basically which has a characteristic of light uh lighted warmed up most um dissolved oxygen are present here and the photosynthesis will occur because of the light penetration and the thermocline or the temperature separation there is this is where the temperature is very abrupt you know pas pascal changes certain predictating area and then the pressure and the buoyancy is a preliminary one and characteristics and preliminion is cold and dark with a possible possible oxygen scarcity oxygen among organisms that's the reason why most of the activities that occur here in these regions are decomposition and aerobic decomposition happens here in this region now um now let's proceed to the classification of organisms based on their position of energy or food chain now so we have already done uh classifying organisms in our aquatic botany we also classify them as autotrophs and heterodrops now here in aquatic ecology we classify them into three the autotrophs the phagotrops and the subpro tropes now what uh cape cabella working autotrophs is already uh familiar to most of to all of you and gaining fatigue drops other tropes you will know for a fact that these are producer organisms or autotrophic for those organisms small green plants and chemosynthetic organisms among microorganisms anglophobia tropes are basically macroconsumers so from the word fudge meaning to see say it no fudge meaning troops macro consumers which are basically primary secondary uh herbivores spread the taurus parasites and many other types of macroconsumers big large organisms okay so these are phagotrops saprothrops however are considered as microconsumers or decomposers okay so these are subclassified according to the nature of organic substrate decomposed so my classified benefits further from organic substrate decomposed so nature or whatsoever decomposed organic or inorganic among a substrate okay so saprotops so again phagotrops are macro consumers supple tropes or microconsumers now another classification are seston seston designates the heterogeneous mixture of living and non-living bodies of organisms which floats or swim in the water so we classify further the system as a biosystem and the biosystem obviously are basically non-living uh heterogeneous uh non-living bodies of of the brace that floats above the water and biosystem are the living like the plankton the neostone the nectar and clear stone so in somebody so we will we will understand that each so first we have uh the organisms of inland waters can be classified as fallows so on semi classes organisms fan found in the lakes the rivers the ponds swamps and marshes types of organisms they can be classified according to uh habitat no when we classify the organisms according to habitat there are organisms considered as the literal organisms literally say they are found near the shore of the lake okay another are limnetic organisms these are pelagic thriving in open waters organisms okay so there are so many pelagic organisms okay so another is benthos so these are bottom dwelling organisms environment environment there and some other bottom dwelling organisms uh benthos so microscopic we could also classify the organisms found in inline waters according to the basis of locomotion locomotion when it's a movement okay so there are uh necton organisms among organisms these are basically organisms that can swim at their own will makalihoxylas however in contrast [Music] are basically the swimmers no matter nekton's example i mean crustaceans molosk and some other larvae and so on so forth among planktons are basically masoplantons phytoplanktons okay so so if you classify the planktons further what are flang tones planktons are designates the heterogeneous assemblage of minute organisms that float and drift at the mercy of waves and other water movements and has a limited power of locomotion except for zooplankton plankton some some of them are are able to so if you if you want to take a look at what are the uh the structures of plankton's municipalities these are all microscopic with your own naked eye you can just observe them as a too big no so flankpon can be uh classified further into uh on the basis of quality know the quality of planktons may be either a plant flankton or the phytoplankton or the zoho plankton or the animal planktons phytoplankton animal plants so phytoplanktons could could further be divided into uh two phytoplankton proper the chlorophyll bearing phytoplankton organisms could able to to process photosynthesis and produce their own food no cancer phytoplankton proper is microconsumers so from the word sapro they are basically uh bacteria and fungi okay so those are the two classifications of plankton according to quality and another classification of plankton the basis of size is three you know macroplankton mesoblancton and nanoplankton and macroplankton are basically larger units of plankton visible to the naked eye with your own eye without an aid of a microscope and then another is mesoplankton the net plankton secured by the plankton net with number 0.25 self bottling cloth no but bolting cloth mesh of point zero three two point zero four millimeters in mesh size okay so how do you classify them mesh they are very minute planktons not secured by the net they are they can be they can be however caught using a net smaller than point zero three millimeters [Music] okay so those are the three classifications of planktons based on the size and then another is the basis of environmental distribution not among plankton's founded lakes we call them as limnoplantons found in the rivers or running water from the word rayo meaning to say curtain no preo [Music] and another are planktons or helioplankton holly plankton are the planktons found in the salt water environment and the breakfast water plantains are called us high palmer planktons okay so phytoplankton but there are another classifications of plants with regards to the environmental distribution you could also classify them according to the basis of origin not originate no there are there are planktons that are locally produced in that particular in aquatic environment so we call them as autogenic planktons however congee conscious other localities delicia endemic we call that as allogenic or allogenetic planktons okay from the word alo means uh allow allow others you know others automatically say otto self not of the so those are the two classifications of planktons based on origin another classification is based on the contents no they're not taking it off niu plankton's [Music] sometimes they can be they composed of uh debris that attaches to the other planktons okay so those are the contents and then uh the basis of life history holoplankton means whole or entire okay so organisms free floating throughout their life so hulu means entire life planck tonsilla look free floating salah entire life and metaplankton are organized free floating at some stage and their stage of their life cycle so part long say long stage planck donsela other parts from gronasselafong depending on the water current they can already move with their own will okay so that is metaplanktons and uh what are the dominant characteristics of plancons you can say that the particular organism is a plankton so basically the most common the most dominant characteristic of a plankton is number one plankton possess no powers of locomotion they cannot move no most of the planktons although there are a few that has cilia and flagella but most of the planktons do not have a power to move do not have a power of locomotion so that is a very important thing to note what are the characteristics of plankton another they inhabit the water column they do not inhabit uh the the the benthic environment they listen to them about the semantic environment they drag itself as a water column another is that they remain suspended or floating in the water and then sometimes they will be carried out with the current and so on so forth so that is another characteristic another is that planktons are producers and consumers of organic water organic matter so for producers can islam autotrophic organisms or autotrophic plants among saprotrophic planktons are the consumers of organic matter most of them are bacteria and fungi microorganisms i okay so we are we are done with uh planktons now let's proceed to the new stone so are composed of a biosystem the non-living and the biocysteine which are the plankton uh the planktons no classified natural plants further nectarines are basically manga moving or the organisms that that that are able to move at their own will so fish and other other organisms quotations no so what are newstone newstone refers to the community of the surface film and uses surface tension for establishing their position like for example genning manga water sliders these are considered as the new stone so it does a surface film so water okay so again new stone are the community or refers to the community of the surface film and uses the surface tension of the property of the water for stabilizing their position so gaining among organisms are examples of new stone and other organisms there are what we call as the sopranostone or the epineuston those are organisms related to the upper surface film like the this one the water sliders the water measures hybrids whirling beetles and certain spiders that the those live upon the upper surface okay so some of the spiders are considered as epinuston okay so that is one another types of new stone are infra-nustone or hyponyeostomy word hyper meaning say embed known as yourself alone other organisms related to the lower surface and those that live beneath the surface films and some of them are bacteria protozoa algae hydra and certain intro most raka and certain insects of larvae and others and usually submerged so this is basically a larvae no larvae has a um i think i'm not sure what larvae is this but this is a larvae a stage or a young stage of the life cycle of an organism this is the surface basically so nash new stone because this is still considered at the surface of the water okay now let's proceed to nektons so again as i have said examples of nectars or nectars are basically the organisms that live or that are that are able to move at their own will they can they do not rely at the water current to move so examples are fishes mammals molosks and some other forms of fishes bony fishes and some others okay so organisms belong to nectars shrimps fishes inhabitants of the water such as reptiles turtles frogs aquatic birds goats and dogs [Music] i hope you can classify each of them and um lastly the benthos okay so bentos or benthic organism again these are organisms that live here for organisms that are found in the benthic environment so again benthos includes all bottom dwelling organisms it consists of the diversified aries plants and animals so benthus plants that live in the benthic environment it includes uranius at the bottom from the uppermost bearing position of the beach to the greatest depth okay as long as uh if it is a plant as long as it has a light that could penetrate at the particular depth of the water and uh most of the vendors are macro fauna and microfana no may be subdivided according to the mode of fitting into like clams animal clams are filter feeders so more filter feeders microfauna and the microphone of emma mancilla so examples of the benthic community is this no benthic community so we have there the black fingered mud crab no mud rub benthic organism can i much as a bottom sea squirts oyster drill this is the ivory among spots of the oyster and some large oyster cluster virginica and the skillet fish that they like the logic area the turkey chaperone is a soft-shelled clams common clam worm ribbon worm and hard plums though considered considered as benthic organisms or bentos some of them are microscopic and some of them are microscopic you know and they have microscopic polymorphic organisms now uh here we have another is the phytoplanktons or of ox amino phytoplankton from the word peri meaning to say surface from the word fi phyton means say plants okay so periphyton or off ox periphyton organisms both plant and animal attach or clinging to stems and leaves of the rooted plants and other projecting above the bottom so tanana grows say for example it's like a seagrass and then organisms gonna grow from other plants are called as periphyton you could classify them further into two no little files these are organisms attached to stones and other solid substrates no lithophiles phytophiles are organisms attached to the water plants or aquatic plants so examples are kidney these are periphytons or a fox so these are lithophiles attached to the stone and some other um forms of phytoplankton organic phytophiles are categorical plants okay so those are examples another are rg are xelophile these are organisms attached on the clay deposits are gelophile substrate are pedophiles okay so more pillow files are further divided into two first is lithoriophile which are organisms attached on the stones and other solid substrates from the word the rayo means to say they are attached to the stones found in the running waters or katonga current among waters okay so um this is basically the compositions of the phytoplankton surrounds mainly composed of protozoans bryozoans or differs undulate worms insects composed of phytoplankton or periphyton community a mass of prey python is likely contained plankton bentos however the plankton are caught and held in tangled attachment forms okay so factors affecting fight periphytons and similar factors it affects the ferry python the water movement could be a factor fluctuation of the water level because there are peripherals that that will be flooded during high tide for example or during flood uh during flood floods and also sometimes chemical characteristics of the environment because some of the the peripherals are very sensitive to the chemical environments present in that particular aquatic environment and uh here we have the last one which are the macrophytes now macrophytes meant to say these are plants that are visible to your naked to your naked eye these are larger aquatic plants that are restricted to the general vicinity of the shores and the shallow water areas these are plants that greatly vary in the degree to which they become truly aquatic no partially submerged and so on so forth okay so uh here we have the different types of aquatic plants no not every mang algae pod or i think these are duckweeds no these are water hyacinths watery leaves and some other types of plants no floating okay so there are what we call as microphytic algae no microphytic algae like chara natalia and other species which form mats either at the bottom or the surface or some occasions they fill the entire water column no penicillin manga microphytic vascular plants either submerged floating lift left and floating or emergent no cancer amino vascular plants when you say vascular plants afternoon discussion botany they have a vascular system okay so nasi lewm and uh xylem and uh here we have the emergent plants those are rooted at the bottom projecting out of the water part of their land okay and floating atom completely floating what are you called uh water bottom submerged these are continuously covered with water sea grass okay so kana and then uh here we have the four types of aquatic plants so again a plant plants uh no major forms of plants shoreline sureland plants so not the emergent floating submerged plants shoreline plants okay okay so macrophytes zones of aquatic microfl microphytes are as follows plants in the beach shore of lake whose roots are enclosed to the ground and so those are basically marginal no beach and shore and zone of emergent hydro fights uh basically emergency submerged it was a bottom and then here we have a zone of floating and hydrophytes this occurs typically next beyond the lake ward in the emergent zone and it's composed of plant rooted to the bottom but their foliage float upon the surface of the water zone of submerged hydrophytes okay this zones occupies a deeper water beyond the zone of floating plants extending downward to the depth to which vary uh with the conditions but in the average water does not exist sec six matters so basically these are the plants located in the the literal zones no limited zones so why why are macrophytes important not only important because higher aquatic plants serves as a breeding place they could support mechanically for for animals like the hydra the sponges the larval cases and some others they could also serve as food for the animals they utilize inorganic substances that we that may somehow be toxic to the to the living organism to the nectars no with shelter or refuge like abode no or the shelter for most organisms sometimes for nursery or a breeding place no six is they produce oxygen through the process of photosynthesis and reduces the effects of wave action by acting as breakers or buffers no so sila so those are the seven factors that basically supports that macro fights are important and ecological problems associated with macrophytes consuming a problem that causes them to be depleted or mogami numbers in that particular aquatic or ecosystem so sometimes they compete with the phytoplankton for the nutrients and light no such that too many fish escape predation and causes an imbalance of fish population so kasagaran they prevent the predation which is basically the the normal um the natural um natural um phenomenon that that occurs in the particular areas so they provide a hiding place and then they sometimes interfere with uh signing or catching a fish like for example uh mangalaya won't say taught oxygen deficiencies by covering the surface of surface and limit the light penetration so basically that the shaded parts they do not promote oxygen uh production because of the shading effect that basically hampers the photosynthesis from from curing that is basically uh promoted by the algae and some other microscopic plants and uh lastly they fill the water column and crowd the area of fish no because i got a lot of areas of fish because they sometimes they sometimes um not dominate na na area so those are the factors that causes uh that that causes problems among macrophytes and then here we have the saprophytes no saprophytes are again organisms responsible for mineralizing nutrients from dead organic material these are this includes bacteria and fungi you know if you want to take a look at bacteria so um bacteria are classified further into aerobic and aerobic bacteria are the bacteria that that decompose organic matters in the presence of oxygen among anaerobic bacterias are bacteria that decomposes organic matters and iron materials in the absence of oxygen so bacteria basically encapsulated diplocoxy [Music] and then some other cyanobacteria spirula vibrio and some other forms of bacteria are are in that form so okay so that is for saprophytes or the organisms that decompose organic materials so classified natural malaysia provides into three autotrophic bacteria saprotrophic bacteria and parasitic bacteria ototrophic basically are some classified into chemosynthetic photosynthetic and heterotrophic bacteria and the saprophytic bacteria are basically the bacteria that ingest and absorb dead organic matter and parasitic bacteria truly process techno within the bodies of organisms that sometimes may cause diseases on a phatogenes no and these are the factors affecting the distribution of bacteria sometimes they are limited with the light the temperature the cementation and the movements of water so there are bacteria that could not tolerate a higher exposure from the sun there are also bacteria that could not tolerate a higher temperature not like 10 classifications of bacteria in the food food hazard consideration so i'm halophiles thermophiles and some other acidophiles so uh from the word files means loving from the word um thermo means high temperature so bacteria is thermophile meaning to say these are bacteria that loves high temperature to grow okay so another factor that basically affects the distribution of bacteria is sedimentation so limitation to say sediment profile of that particular area or bottom organic particles are used as attachment bacteria any changes that will affect their distributions also sometimes movements of water it has a direct effect of distribution to the bacterial composition of the aquatic environment now lastly could also be the uh factor in the distribution of bacteria are the food supply you know sagaran among areas are scarce and foods so sometimes they it will not allow the growth of mainly bacteria other microorganisms so sometimes they have this competition and sometimes because of the scarcity of food they basically become become limited in numbers and sometimes we can become um location organic matter and bottom deposits this refers to the nature of substrate no bonsai classic substrate it may be uh muddy substrate rocky substrates sandy substrate or a substrate that has a very diverse benthic environment or benthic organisms sometimes ph could also be a factor you know high fa high ph flavors favors the growth of bacteria acidic organisms among areas are very suitable for organisms that grow on that that acidic environment we term them we classify that bacteria as acidophilic bacterias okay so that ends our discussion on the module uh module freshwater ecosystems okay so on our next module we will be to see we will be discussing on the uh coastal environment so that ends our third module now uh as a form of your uh in your task number task three we post there is a new on google classroom uh first one task seven basically will you all you will be required to expound the three reasons why fresh water is important so that is 10 points another is that you are going to compare and contrast the lakes plants swamps and explain its atlantic series so when we say compare and contrast meaning to say emo shantan yang similarity and then after cylinder similarity between puns lakes and swamps differences so that is what we meant by compare and contrast similarities first and then differences after and also you're going to explain its lengthic series explain and succession lintic environment okay so that is all 20 points as your task 7. and among task 8 you will be explaining each of the different causes of succession in the atlantic series also 10 points and then number four is explain the different causes of succession in the low tech series another 10 points so you could answer that in a sheet of paper or in that task 8 word okay so that is your task a task nine would be identify what type of lake are there or are the five major lakes of the philippines again mentioned you will be explaining why temperature and light are the limiting factors in the freshwater ecosystem why temperature is considered as a limiting factor and why light is also considered as a limiting factor in the freshwater environment okay and number seven you're going to explain the graph so i have their graph epilim neon thermocline or hypolimnion so local layers you explain temperature uh distribution sakada layer is okay so explain that is your task 9. task 10 will be compare and contrast the literal lemnetic profandal zones of delay so 10 points another compare and contrast upon similarities and then differences of autotrophs phagotropes and saprotrophs and differentiate plankton neostone necktones and benthos that is another 10 points so some of you have already submitted one no no no there is a task nine will append and submit there is a task either and so with task 7. so if you have any questions you may chat your questions at our group chat so for the meantime please answer your task from task 1 to task 10. i'll see you again on our next episode thank you so much for staying in at this very moment so salaam at sapang this is basically a one hour and 35 minutes in recording so again thank you so much for uh listening and i hope to see you again on our next episode thank you