Fabio de Freitas - Pd. 5

Riparian Zone Retreat and Riparian Zone Retreat and Population StudiesPopulation Studies

Fabio de FreitasFabio de Freitas

Honors Biology IIHonors Biology II

Period 5Period 5

The OtterThe Otter

Niche of the Northern River Niche of the Northern River Otter (Otter (Lontra canadensisLontra canadensis))

North American river otters are semi-aquatic mammals with long, North American river otters are semi-aquatic mammals with long, streamlined bodies, thick tapered tails, short legs, wide rounded heads, streamlined bodies, thick tapered tails, short legs, wide rounded heads, small ears, and nostrils that can be closed underwater.small ears, and nostrils that can be closed underwater.

North American river otters can be found anywhere with a permanent North American river otters can be found anywhere with a permanent food supply and easy access to water. They can live in freshwater (rivers, food supply and easy access to water. They can live in freshwater (rivers, lakes, swamps) and coastal marine habitats. River otters tolerate different lakes, swamps) and coastal marine habitats. River otters tolerate different environments, such as cold and warmer latitudes and high elevations, but environments, such as cold and warmer latitudes and high elevations, but North American river otters seem to be sensitive to pollution and North American river otters seem to be sensitive to pollution and disappear from areas with polluted waters. disappear from areas with polluted waters.

They build dens in the burrows of other mammals, in natural hollows, They build dens in the burrows of other mammals, in natural hollows, such as under a log, or in river banks. These dens have underwater such as under a log, or in river banks. These dens have underwater entrances and a tunnel leading to a nest chamber that is lined with entrances and a tunnel leading to a nest chamber that is lined with various materials (leaves, grass, moss, bark, hair).various materials (leaves, grass, moss, bark, hair).

The North American river otters’ diet is based mainly upon aquatic organisms The North American river otters’ diet is based mainly upon aquatic organisms (amphibians, fish, turtles, crayfish, crabs, other invertebrates). However, they (amphibians, fish, turtles, crayfish, crabs, other invertebrates). However, they can also eat birds, their eggs, and small terrestrial mammals as well as some can also eat birds, their eggs, and small terrestrial mammals as well as some aquatic plants. On the other hand, the otters are eaten by bobcats, coyotes, aquatic plants. On the other hand, the otters are eaten by bobcats, coyotes, birds of prey, alligators, and other large predators.birds of prey, alligators, and other large predators.

Whenever it hunts (mostly at night), the Northern River otter captures the prey Whenever it hunts (mostly at night), the Northern River otter captures the prey by the mouth and its long whiskers are used to detect organisms in the by the mouth and its long whiskers are used to detect organisms in the substrate and the dark water. The prey is eaten right after it is captured, most substrate and the dark water. The prey is eaten right after it is captured, most likely in the water, but it can be eaten on land if it is a bigger prey.likely in the water, but it can be eaten on land if it is a bigger prey.

Lontra canadensisLontra canadensis individuals live alone or in small groups formed by the individuals live alone or in small groups formed by the female and its young. They are known as playful animals, and such behavior female and its young. They are known as playful animals, and such behavior can be used to make social bonds stronger, practice hunting techniques, and to can be used to make social bonds stronger, practice hunting techniques, and to scent mark. They are very good swimmers and divers, as well as fast on land.scent mark. They are very good swimmers and divers, as well as fast on land.

They are able to communicate in many ways, such as vocalizing (whistles, They are able to communicate in many ways, such as vocalizing (whistles, growls), producing odors through scent glands, and also by touch, posture, and growls), producing odors through scent glands, and also by touch, posture, and other body signals. In order to perceive the environment, they use vision, touch, other body signals. In order to perceive the environment, they use vision, touch, smell, and hearing; their whiskers are very important in tactile sensation.smell, and hearing; their whiskers are very important in tactile sensation.

Factors which affect Birth Rate of Northern River Otters

Male and female otters come together to breed, only, in late winter Male and female otters come together to breed, only, in late winter or late spring. Gestation lasts about two months, but the young or late spring. Gestation lasts about two months, but the young may be born up to a year after mating since these otters employ may be born up to a year after mating since these otters employ delayed implantation of the fertilized egg in the uterus. delayed implantation of the fertilized egg in the uterus.

Females give birth to from 1 to 6 young at a time (with an average Females give birth to from 1 to 6 young at a time (with an average of 2 to 3), nurse, and care for them in a den near the water.of 2 to 3), nurse, and care for them in a den near the water.

The male river otter often approaches females and attempts to The male river otter often approaches females and attempts to hug her with his legs or rub and sniff her body. If she is receptive hug her with his legs or rub and sniff her body. If she is receptive to him, the two roll and frolic; if not, she will push him away. to him, the two roll and frolic; if not, she will push him away. Copulation is preceded by active play. It takes place in the water, Copulation is preceded by active play. It takes place in the water, and lasts 10 to 30 minutes.and lasts 10 to 30 minutes.

Factors which affect the Death Rate of Northern River Otters

The Northern River otter captures the prey by the mouth and its The Northern River otter captures the prey by the mouth and its long whiskers are used to detect organisms in the substrate and long whiskers are used to detect organisms in the substrate and the dark water. The prey is eaten right after it is captured, most the dark water. The prey is eaten right after it is captured, most likely in the water, but it can be eaten on land if it is a bigger prey.likely in the water, but it can be eaten on land if it is a bigger prey.

North American River otters can live up to 21 years in captivity or North American River otters can live up to 21 years in captivity or 8 to 9 years in nature.8 to 9 years in nature.

River otters are also susceptible to parasitic infestations by flukes, River otters are also susceptible to parasitic infestations by flukes, roundworms, tapeworms, and possibly ticks.roundworms, tapeworms, and possibly ticks.

If an area becomes overpopulated with otters, there will be an If an area becomes overpopulated with otters, there will be an increased fight among individuals for food as well as over mating increased fight among individuals for food as well as over mating partners.partners.

Food Chain of the Northern Food Chain of the Northern River Otter River Otter ((Lontra Lontra canadensiscanadensis))

Producer

Autotrophic

Primary Consumer

Omnivore

Secondary Consumer

Carnivore

Tertiary Consumer

Carnivore

Food Web of the Northern River Food Web of the Northern River Otter (Otter (Lontra canadensis)Lontra canadensis)

Producer

Decomposer

Decomposer

HerbivoreCarnivore

Carnivore

Carnivore

Carnivore

Omnivore

Omnivore

Population Sampling Population Sampling TechniquesTechniques

There are 3 main types of sampling:

-Probability sampling, in which each sample has the same probability of being chosen.

-Purposive sampling, in which whoever is selecting the sample is the one who tries to make the sample representative, depending upon their opinion or purpose, therefore being the representation subjective.

-No-rule sampling, in which a sample is taken without any rules (that is, without bias), being the sample representative if the population is homogeneous.

In order to estimate the size of the Otter’s population, a technique that can be used is: capture, mark and release back some individuals; then, a few days later, capture both marked and unmarked animals and find the approximate population number by multiplying the pre-marked individuals by both marked and unmarked individuals captured later and, then, dividing this number by only the marked individuals captured the second time.

Stream Quality Data & Stream Quality Data & AnalysisAnalysis

The stream represented by the graph is a The stream represented by the graph is a very healthy one.very healthy one.

Class I organisms are generally pollution-Class I organisms are generally pollution-intolerant, so great number of these in a intolerant, so great number of these in a stream generally indicates good water stream generally indicates good water quality. Class II organisms are somewhat quality. Class II organisms are somewhat tolerant of water pollution, being able to exist tolerant of water pollution, being able to exist in a wide range of water quality. Class III in a wide range of water quality. Class III organisms are generally tolerant of pollution; organisms are generally tolerant of pollution; their dominance usually indicates poor water their dominance usually indicates poor water quality.quality.

Since the Northern River Otter usually lives Since the Northern River Otter usually lives in pollution-free areas, this particular stream in pollution-free areas, this particular stream would be an appropriate location for the would be an appropriate location for the animal to be born, grow up, and reproduce.animal to be born, grow up, and reproduce.

If the majority of organisms found in this If the majority of organisms found in this stream were from Class III (pollution-stream were from Class III (pollution-tolerant), it would indicate a poor water tolerant), it would indicate a poor water quality and, therefore, a not convenient place quality and, therefore, a not convenient place for Northern River Otters to live in. for Northern River Otters to live in.

Water Testing Data and Water Testing Data and AnalysisAnalysis

Nitrogen is essential to proper Nitrogen is essential to proper functioning of plant metabolism . It is functioning of plant metabolism . It is passed up the food chain, being passed up the food chain, being needed for both protein and nucleic needed for both protein and nucleic acids production. Phosphorus is the acids production. Phosphorus is the most important nutrient in root most important nutrient in root formation, encourages blooming and formation, encourages blooming and seed formation, and increases plants’ seed formation, and increases plants’ resistance to weather and disease. It is resistance to weather and disease. It is needed for ATP and nucleic acids’ needed for ATP and nucleic acids’ production (in the form of phosphates). production (in the form of phosphates). Plants and other organisms also need Plants and other organisms also need the correct pH level to function well. the correct pH level to function well. The most ideal level would be between The most ideal level would be between 6.5 and 7.5. Oxygen is essential to the 6.5 and 7.5. Oxygen is essential to the living things in streams. A stream with a living things in streams. A stream with a good amount of dissolved oxygen good amount of dissolved oxygen supports many different organisms. If it supports many different organisms. If it is depleted, it can kill some – or all – life is depleted, it can kill some – or all – life depending on it.depending on it.

The ideal ranges for these factors are: Nitrates – none. Phosphates – The ideal ranges for these factors are: Nitrates – none. Phosphates – none. pH – 6.5 to 7.5. Oxygen – 10 to 15 mg/L. Some variations may none. pH – 6.5 to 7.5. Oxygen – 10 to 15 mg/L. Some variations may occur due to possible errors during collection and/or analysis.occur due to possible errors during collection and/or analysis.

The Otter would successfully inhabit areas near the healthy stream, but The Otter would successfully inhabit areas near the healthy stream, but not near the mine or the marsh, since polluted areas cannot be inhabited not near the mine or the marsh, since polluted areas cannot be inhabited by this organism.by this organism.

is an important factor to the quality of streams. Warmer waters hold less is an important factor to the quality of streams. Warmer waters hold less oxygen since evaporation is easier to occur. Colder waters will hold more oxygen since evaporation is easier to occur. Colder waters will hold more oxygen and maybe support a wider range of life.oxygen and maybe support a wider range of life.

Turbidity also plays an important role in stream life. Clear waters are Turbidity also plays an important role in stream life. Clear waters are ideal. Waters with high turbidity can affect predator-prey relations, clog ideal. Waters with high turbidity can affect predator-prey relations, clog gills, make the stream’s bottom too slippery for organisms to hold on to it, gills, make the stream’s bottom too slippery for organisms to hold on to it, and also decrease the rate of photosynthesis (since the sunlight cannot and also decrease the rate of photosynthesis (since the sunlight cannot reach parts of the stream).reach parts of the stream).

Soil Testing and AnalysisSoil Testing and Analysis

Nitrogen is essential to proper Nitrogen is essential to proper functioning of plant metabolism . It is functioning of plant metabolism . It is passed up the food chain, being passed up the food chain, being needed for both protein and nucleic needed for both protein and nucleic acids production. Phosphorus is the acids production. Phosphorus is the most important nutrient in root most important nutrient in root formation; it encourages blooming formation; it encourages blooming and seed formation, and increases and seed formation, and increases plants’ resistance to weather and plants’ resistance to weather and disease. It is needed for ATP and disease. It is needed for ATP and nucleic acids’ production (in the form nucleic acids’ production (in the form of phosphates). Potassium stimulates of phosphates). Potassium stimulates flowering and is needed in flowering and is needed in photosynthesis to make sugars. photosynthesis to make sugars. Plants and other organisms also Plants and other organisms also need the correct pH level to function need the correct pH level to function well. The ideal level would be well. The ideal level would be between 6.5 and 7.5 (which can between 6.5 and 7.5 (which can support a wide range of life). support a wide range of life).

Unlike streams, the soil needs high levels of all these Unlike streams, the soil needs high levels of all these chemicals in order to support plant life. Plants actually chemicals in order to support plant life. Plants actually need such nutrients, that play a great role in their need such nutrients, that play a great role in their growth and metabolism.growth and metabolism.

As long as these chemicals are used in a conscious As long as these chemicals are used in a conscious way, that is fine. However, if humans use too much of way, that is fine. However, if humans use too much of them, there can be the danger of leaking into nearby them, there can be the danger of leaking into nearby streams and groundwater, which can severely affect streams and groundwater, which can severely affect both human and animal life.both human and animal life.

Positive and Negative Positive and Negative FactorsFactors

The healthy stream would be a very suitable location to the Northern River Otter. The healthy stream would be a very suitable location to the Northern River Otter. The mine and marsh waters, however, are too polluted to support this particular The mine and marsh waters, however, are too polluted to support this particular organism, which is considerably sensitive to pollution.organism, which is considerably sensitive to pollution.

The low levels of nitrogen and phosphorus favor this organism sensitive to polluted The low levels of nitrogen and phosphorus favor this organism sensitive to polluted areas. The acidic pH and the high level of potassium, however, could directly or areas. The acidic pH and the high level of potassium, however, could directly or indirectly affect the Otter’s health.indirectly affect the Otter’s health.

Several factors affect the riparian zone. While high levels of nutrients (such as Several factors affect the riparian zone. While high levels of nutrients (such as nitrates, phosphates, and potassium) are needed in the soil for plant life, such nitrates, phosphates, and potassium) are needed in the soil for plant life, such levels will greatly harm stream waters, killing its living organisms. Also, low levels will greatly harm stream waters, killing its living organisms. Also, low temperature, neutral pH, and low turbidity will favor life in the stream. The main temperature, neutral pH, and low turbidity will favor life in the stream. The main causes of pollution in Pennsylvania’s streams are Abandoned Mine Drainage causes of pollution in Pennsylvania’s streams are Abandoned Mine Drainage (AMD) and Farmland Runoff. In order to preserve the ecosystem, several actions (AMD) and Farmland Runoff. In order to preserve the ecosystem, several actions can be done, such as reduce the amount of chemicals used in fields and lawns, can be done, such as reduce the amount of chemicals used in fields and lawns, keep the vegetation alive, use crop rotation, treat polluted areas, and practice keep the vegetation alive, use crop rotation, treat polluted areas, and practice ecotourism, among many other. If a stream is free of pollution and can support a ecotourism, among many other. If a stream is free of pollution and can support a variety of different living organisms, then it will certainly be a great place for the variety of different living organisms, then it will certainly be a great place for the Northern River Otter to live. Northern River Otter to live.

ConclusionConclusion

One of the new things I learned about the ecosystem One of the new things I learned about the ecosystem was that, while high levels of nutrients such as nitrates was that, while high levels of nutrients such as nitrates and phosphates are needed in the soil, they can be and phosphates are needed in the soil, they can be extremely harmful to life in streams.extremely harmful to life in streams.

One interesting fact is that the Northern River Otter One interesting fact is that the Northern River Otter cannot bear polluted areas, being, therefore, a cannot bear polluted areas, being, therefore, a biological indicator in order to determine a stream’s biological indicator in order to determine a stream’s quality.quality.

I would like to learn more about how to prevent I would like to learn more about how to prevent pollution from harming certain areas, as well as how to pollution from harming certain areas, as well as how to treat the areas that are already polluted. treat the areas that are already polluted.

Works CitedWorks Cited

"Lontra canadensis (northern river otter)." "Lontra canadensis (northern river otter)." Animal Diversity WebAnimal Diversity Web. . University of Michigan Museum of Zoology, 2008. Web. 13 May University of Michigan Museum of Zoology, 2008. Web. 13 May 2010. <http://animaldiversity.ummz.umich.edu/site/accounts/ 2010. <http://animaldiversity.ummz.umich.edu/site/accounts/ information/Lontra_canadensis.html>.information/Lontra_canadensis.html>.

"Lontra canadensis (Schreber, 1777)." "Lontra canadensis (Schreber, 1777)." Encyclopedia of LifeEncyclopedia of Life. N.p., . N.p., n.d. Web. 13 May 2010. <http://www.eol.org/pages/328584>. n.d. Web. 13 May 2010. <http://www.eol.org/pages/328584>.

Ligonier Valley High School – Honors Biology II class notes.Ligonier Valley High School – Honors Biology II class notes.