We are searching data for your request:
Upon completion, a link will appear to access the found materials.
- Define ecology and the four levels of ecological research
When a discipline such as biology is studied, it is often helpful to subdivide it into smaller, related areas. For instance, cell biologists interested in cell signaling need to understand the chemistry of the signal molecules (which are usually proteins) as well as the result of cell signaling. The same subdivisions occur in ecology. Ecologists interested in the factors that influence the survival of an endangered species might use mathematical models to predict how current conservation efforts affect endangered organisms. To produce a sound set of management options, a conservation biologist needs to collect accurate data, including current population size, factors affecting reproduction (like physiology and behavior), habitat requirements (such as plants and soils), and potential human influences on the endangered population and its habitat (which might be derived through studies in sociology and urban ecology). Within the discipline of ecology, researchers work at four specific levels, sometimes discretely and sometimes with overlap: organism, population, community, and ecosystem (Figure 1).
Researchers studying ecology at the organismal level are interested in the adaptations that enable individuals to live in specific habitats. These adaptations can be morphological, physiological, and behavioral. For instance, the Karner blue butterfly (Lycaeides melissa samuelis) is a rare butterfly that lives only in open areas with few trees or shrubs, such as pine barrens and oak savannas. It is considered a specialist because the females preferentially oviposit (that is, lay eggs) on wild lupine (Figure 2). This preferential adaptation means that the Karner blue butterfly is highly dependent on the presence of wild lupine plants for its continued survival.
After hatching, the larval caterpillars emerge and spend four to six weeks feeding solely on wild lupine. The caterpillars pupate (undergo metamorphosis) and emerge as butterflies after about four weeks. The adult butterflies feed on the nectar of flowers of wild lupine and other plant species. A researcher interested in studying Karner blue butterflies at the organismal level might, in addition to asking questions about egg laying, ask questions about the butterflies’ preferred temperature (a physiological question) or the behavior of the caterpillars when they are at different larval stages (a behavioral question).
A population is a group of interbreeding organisms that are members of the same species living in the same area at the same time. (Organisms that are all members of the same species are called conspecifics.) A population is identified, in part, by where it lives, and its area of population may have natural or artificial boundaries: natural boundaries might be rivers, mountains, or deserts, while examples of artificial boundaries include mowed grass, manmade structures, or roads. The study of population ecology focuses on the number of individuals in an area and how and why population size changes over time. Population ecologists are particularly interested in counting the Karner blue butterfly, for example, because it is classified as federally endangered. However, the distribution and density of this species is highly influenced by the distribution and abundance of wild lupine. Researchers might ask questions about the factors leading to the decline of wild lupine and how these affect Karner blue butterflies. For example, ecologists know that wild lupine thrives in open areas where trees and shrubs are largely absent. In natural settings, intermittent wildfires regularly remove trees and shrubs, helping to maintain the open areas that wild lupine requires. Mathematical models can be used to understand how wildfire suppression by humans has led to the decline of this important plant for the Karner blue butterfly.
A biological community consists of the different species within an area, typically a three-dimensional space, and the interactions within and among these species. Community ecologists are interested in the processes driving these interactions and their consequences. Questions about conspecific interactions often focus on competition among members of the same species for a limited resource. Ecologists also study interactions among various species; members of different species are called heterospecifics. Examples of heterospecific interactions include predation, parasitism, herbivory, competition, and pollination. These interactions can have regulating effects on population sizes and can impact ecological and evolutionary processes affecting diversity.
For example, Karner blue butterfly larvae form mutualistic relationships with ants. Mutualism is a form of a long-term relationship that has coevolved between two species and from which each species benefits. For mutualism to exist between individual organisms, each species must receive some benefit from the other as a consequence of the relationship. Researchers have shown that there is an increase in the probability of survival when Karner blue butterfly larvae (caterpillars) are tended by ants. This might be because the larvae spend less time in each life stage when tended by ants, which provides an advantage for the larvae. Meanwhile, the Karner blue butterfly larvae secrete a carbohydrate-rich substance that is an important energy source for the ants. Both the Karner blue larvae and the ants benefit from their interaction.
Ecosystem ecology is an extension of organismal, population, and community ecology. The ecosystem is composed of all the biotic components (living things) in an area along with the abiotic components (non-living things) of that area. Some of the abiotic components include air, water, and soil. Ecosystem biologists ask questions about how nutrients and energy are stored and how they move among organisms and the surrounding atmosphere, soil, and water.
The Karner blue butterflies and the wild lupine live in an oak-pine barren habitat. This habitat is characterized by natural disturbance and nutrient-poor soils that are low in nitrogen. The availability of nutrients is an important factor in the distribution of the plants that live in this habitat. Researchers interested in ecosystem ecology could ask questions about the importance of limited resources and the movement of resources, such as nutrients, though the biotic and abiotic portions of the ecosystem.
Watch this video for another introduction to ecology:
A YouTube element has been excluded from this version of the text. You can view it online here: pb.libretexts.org/fob1/?p=510
Ecology can also be classified on the basis of:
- the primary kinds of organism under study (e.g. animal ecology, plant ecology, insect ecology)
- the biomes principally studied (e.g. forest ecology, grassland ecology, desert ecology, benthic ecology, marine ecology, urban ecology)
- the geographic or climatic area (e.g. arctic ecology, tropical ecology)
- the spatial scale under consideration (e.g. macroecology, landscape ecology)
- the philosophical approach (e.g. systems ecology which adopts a holistic approach)
- the methods used (e.g. molecular ecology)
17.4 Applying Genomics
In this section, you will explore the following questions:
Connection for AP ® Courses
Information presented in section is not in scope for AP ® . However, you can study information in the section as optional or illustrative material.
Predicting Disease Risk at the Individual Level:
Cancer, heart disease, and stroke account for a large number of health problems in developed countries. Genomics is a tool which allows physicians to predict who may be susceptible to particular cancers and what someone’s risk of heart disease is. This is making adjustments in life style and important to prolonging life.
Pharmacogenomics and Toxicogenomics:
Assign the class the job of identifying drugs from the literature whose metabolism is susceptible to genetic variation in patients. Can pharmacogenomics benefit these patients?
Microbial Genomics: Creation of New Biofuels, Mitochondrial Genomics, Genomics in Agriculture:
Assign three groups from the class to investigate the following questions. What biofuels are on the market and what has their impact been on energy use? Why are mitochondrial genes examined in forensic cases, but not nuclear chromosomal material? What effects have agricultural applications of genomics had?
The introduction of DNA sequencing and whole genome sequencing projects, particularly the Human Genome project, has expanded the applicability of DNA sequence information. Genomics is now being used in a wide variety of fields, such as metagenomics, pharmacogenomics, and mitochondrial genomics. The most commonly known application of genomics is to understand and find cures for diseases.
Predicting Disease Risk at the Individual Level
Predicting the risk of disease involves screening currently healthy individuals by genome analysis at the individual level. Intervention with lifestyle changes and drugs can be recommended before disease onset. However, this approach is most applicable when the problem resides within a single gene defect. Such defects only account for approximately 5 percent of diseases in developed countries. Most of the common diseases, such as heart disease, are multi-factored or polygenic , which is a phenotypic characteristic that involves two or more genes, and also involve environmental factors such as diet. In April 2010, scientists at Stanford University published the genome analysis of a healthy individual (Stephen Quake, a scientist at Stanford University, who had his genome sequenced) the analysis predicted his propensity to acquire various diseases. A risk assessment was performed to analyze Quake’s percentage of risk for 55 different medical conditions. A rare genetic mutation was found, which showed him to be at risk for sudden heart attack. He was also predicted to have a 23 percent risk of developing prostate cancer and a 1.4 percent risk of developing Alzheimer’s. The scientists used databases and several publications to analyze the genomic data. Even though genomic sequencing is becoming more affordable and analytical tools are becoming more reliable, ethical issues surrounding genomic analysis at a population level remain to be addressed.
- In general, all men should be screened to minimize risks of prostate cancer.
- In general, all men should be given prevantative treatment irrespective of the presence or absence of cancer symptoms.
- In general, no men should be screened due to risks of treatment.
- In general, only men suspected of having prostate cancer should be screened.
Pharmacogenomics and Toxicogenomics
Pharmacogenomics , also called toxicogenomics, involves evaluating the effectiveness and safety of drugs on the basis of information from an individual's genomic sequence. Genomic responses to drugs can be studied using experimental animals (such as laboratory rats or mice) or live cells in the laboratory before embarking on studies with humans. Studying changes in gene expression could provide information about the transcription profile in the presence of the drug, which can be used as an early indicator of the potential for toxic effects. For example, genes involved in cellular growth and controlled cell death, when disturbed, could lead to the growth of cancerous cells. Genome-wide studies can also help to find new genes involved in drug toxicity. Personal genome sequence information can be used to prescribe medications that will be most effective and least toxic on the basis of the individual patient’s genotype. The gene signatures may not be completely accurate, but can be tested further before pathologic symptoms arise.
Microbial Genomics: Metagenomics
Traditionally, microbiology has been taught with the view that microorganisms are best studied under pure culture conditions, which involves isolating a single type of cell and culturing it in the laboratory. Because microorganisms can go through several generations in a matter of hours, their gene expression profiles adapt to the new laboratory environment very quickly. In addition, the vast majority of bacterial species resist being cultured in isolation. Most microorganisms do not live as isolated entities, but in microbial communities known as biofilms. For all of these reasons, pure culture is not always the best way to study microorganisms. Metagenomics is the study of the collective genomes of multiple species that grow and interact in an environmental niche. Metagenomics can be used to identify new species more rapidly and to analyze the effect of pollutants on the environment (Figure 17.15).
Microbial Genomics: Creation of New Biofuels
Knowledge of the genomics of microorganisms is being used to find better ways to harness biofuels from algae and cyanobacteria. The primary sources of fuel today are coal, oil, wood, and other plant products, such as ethanol. Although plants are renewable resources, there is still a need to find more alternative renewable sources of energy to meet our population’s energy demands. The microbial world is one of the largest resources for genes that encode new enzymes and produce new organic compounds, and it remains largely untapped. Microorganisms are used to create products, such as enzymes that are used in research, antibiotics, and other anti-microbial mechanisms. Microbial genomics is helping to develop diagnostic tools, improved vaccines, new disease treatments, and advanced environmental cleanup techniques.
Mitochondria are intracellular organelles that contain their own DNA. Mitochondrial DNA mutates at a rapid rate and is often used to study evolutionary relationships. Another feature that makes studying the mitochondrial genome interesting is that the mitochondrial DNA in most multicellular organisms is passed on from the mother during the process of fertilization. For this reason, mitochondrial genomics is often used to trace genealogy.
Information and clues obtained from DNA samples found at crime scenes have been used as evidence in court cases, and genetic markers have been used in forensic analysis. Genomic analysis has also become useful in this field. In 2001, the first use of genomics in forensics was published. It was a collaborative attempt between academic research institutions and the FBI to solve the mysterious cases of anthrax communicated via the US Postal Service. Using microbial genomics, researchers determined that a specific strain of anthrax was used in all the mailings.
Genomics in Agriculture
Genomics can reduce the trials and failures involved in scientific research to a certain extent, which could improve the quality and quantity of crop yields in agriculture. Linking traits to genes or gene signatures helps to improve crop breeding to generate hybrids with the most desirable qualities. Scientists use genomic data to identify desirable traits, and then transfer those traits to a different organism. Scientists are discovering how genomics can improve the quality and quantity of agricultural production. For example, scientists could use desirable traits to create a useful product or enhance an existing product, such as making a drought-sensitive crop more tolerant of the dry season.
Branches of Ecology and Levels of Ecological Organisation
It involves the study of an individual animal or plant throughout its life in relation to the habitat factors. For autecological studies one must have the knowledge of nutrition, growth, reproduction and development of that individual.
If composition and behaviour of plant communities and their relationship to the environment are studied, the subject is called synecology. Synecology is often further subdivided into aquatic and terrestrial ecology.
(i) The aquatic ecology includes fresh water ecology, estuarine ecology and marine ecology.
(ii) Terrestrial ecology, subdivided further into areas such as forest ecology, grassland ecology, cropland ecology and desert ecology, is concerned with terrestrial (land) ecosystems — their microclimate, soil chemistry, nutrient, hydrological cycle and productivity.
Levels of Ecological Organisation (Ecological Hierarchy):
Ecology is basically concerned with various levels of biological organisation – organisms, populations, communities, ecosystems and biomes.
The hierarchy in the levels of organisation connected with ecological grouping of organisms is called ecological hierarchy or ecological levels of organisation.
(i) Individual (Organism) is distinct living entity or distinct package which carries out all life processes in its body, separate from those in other individuals.
Individual organism is the basic unit of ecological hierarchy as it continuously exchanges materials and information with its environment.
(ii) Population is a group of individuals of the same species living together in a common area at a particular time.
Organisms of the same kind may form several populations inhabiting different geographical areas:
1. The different populations of the same kind of organisms are often referred to as local population.
2. Members of a local population may be genetically adapted to their specific environment, such a population is called ecotype.
3. In a given geographical area, a population is further divisible into sub-groups called demes.
4. The interactions between individuals of the same species are more in the members of same deme than between members of different demes.
(iii) Biotic Community is an assemblage of population of different species of plants, animals, bacteria and fungi which live in a particular area and interact with one another through competition, predation, mutualism etc.
(iv) Ecosystem is a segment of nature consisting of a biological community and its physical environment both interacting and exchanging materials as well as energy.
(v) Landscape is a unit of land distinguished by a natural boundary and having patches of different ecosystems.
(vi) Biome is a large regional unit delimited by a specific climatic zone, having a particular major vegetation zone and its associated fauna, e.g., tundra desert, temperate deciduous forest, tropical rain forest, ocean.
(vii) Biosphere is biologically inhabited part of earth along with its physical environment consisting of lower atmosphere, land and water bodies.
Ecological Pyramids and Its Limitations | Biology
These are the diagrammatic illustrations of connection between different trophic levels in terms of energy, biomass and number of an organism. The base of each pyramid represents the producers or the first trophic level. Apex represents tertiary or top level consumers. In general, all pyramids are upright, but there are few exceptions.
There are three ecological pyramids that are usually studies:
It represents the total number of organisms at each trophic level. It is always upright but in a tree ecosystem pyramid of number is inverted.
It represents total weight of the organisms in each trophic level.
(i) Upright, e.g., in grasslands.
(ii) Inverted, e.g., in pond ecosystem.
It represents total energy of the organisms in each trophic level. Pyramid of energy is always upright, i.e., it can never be inverted, because when energy is transferred from a particular trophic level to the next trophic level some energy is always lost as heat at each step.
Some important points about ecological pyramids are given under:
(i) A given organism may occupy more than one trophic level simultaneously.
(ii) Trophic level represents a functional level.
(iii) A given species may occupy more than one trophic level in the same ecosystem at the same time.
For example, a sparrow is primary consumer, when it eats seeds, fruit, peas, etc., and a secondary consumer when it eats insects and worms.
(iv) In most ecosystems, all the pyramids of number, biomass, energy are upright, i.e., producers are more in number and biomass than the herbivores and herbivores are more in number and biomass than carnivores.
(v) Also energy at lower trophic level is always more at higher trophic level. However, there are exceptions to this generalisation.
(vi) Pyramid of biomass in sea is inverted because the biomass of fishes far exceeds that of phytoplankton.
(vii) Each bar in the energy pyramid indicates the amount of energy present at each trophic level in a given time or annually per unit area.
Limitations of Ecological Pyramids:
(i) It never takes into account the same species belonging to two or more trophic levels.
(ii) It assumes a simple food chain, something that almost never exists in nature.
(iii) It does not accommodate a food web.
(iv) Saprophytes are not given any place in ecological pyramids even though they play an important role in ecosystem.
A population is a group of interbreeding organisms that are members of the same species living in the same area at the same time. (Organisms that are all members of the same species are called conspecifics .) A population is identified, in part, by where it lives, and its area of population may have natural or artificial boundaries: natural boundaries might be rivers, mountains, or deserts, while examples of artificial boundaries include mowed grass, manmade structures, or roads. The study of population ecology focuses on the number of individuals in an area and how and why population size changes over time. Population ecologists are particularly interested in counting the Karner blue butterfly, for example, because it is classified as federally endangered. However, the distribution and density of this species is highly influenced by the distribution and abundance of wild lupine. Researchers might ask questions about the factors leading to the decline of wild lupine and how these affect Karner blue butterflies. For example, ecologists know that wild lupine thrives in open areas where trees and shrubs are largely absent. In natural settings, intermittent wildfires regularly remove trees and shrubs, helping to maintain the open areas that wild lupine requires. Mathematical models can be used to understand how wildfire suppression by humans has led to the decline of this important plant for the Karner blue butterfly.
Areas of study
Ecology is necessarily the union of many areas of study because its definition is so all-encompassing. There are many kinds of relationships between organisms and their environment. By organisms one might mean single individuals, groups of individuals, all the members of one species, the sum of many species, or the total mass of species (biomass) in an ecosystem. And the term environment includes not only physical and chemical features but also the biological environment, which involves yet more organisms.
In practice, ecology is composed of broadly overlapping approaches and further divided by the groups of species to be studied. There are many, for example, who specialize in the field of “bird behavioral ecology.” The main approaches fall into the following classes.
Evolutionary ecology examines the environmental factors that drive species adaptation. Studies of the evolution of species might seek to answer the question of how populations have changed genetically over several generations but might not necessarily attempt to learn what the underlying mechanisms might be. Evolutionary ecology seeks those mechanisms. Thus, in the well-known example of the peppered moth, the populations in the industrialized English Midlands changed over generations from having wings coloured largely grayish white, peppered with black spots, to wings that were mostly blackish. The ecological mechanism involved predation—birds readily detected the light-coloured moths against the background of the tree trunks that industrial pollution had darkened, whereas the dark-coloured moths remained generally undetected.
Evolutionary ecology also examines broader issues, such as the observations that plants in arid environments often have no leaves or else very small ones or that some species of birds have helpers at the nest—individuals that raise young other than their own. A critical question for the subject is whether a set of adaptations arose once and has simply been retained by all species descended from a common ancestor having those adaptations or whether the adaptations evolved repeatedly because of the same environmental factors. In the case of plants that live in arid environments, cacti from the New World and euphorbia (see spurge) from the Old World can look strikingly similar even though they are in unrelated plant families.
Physiological ecology asks how organisms survive in their environments. There is often an emphasis on extreme conditions, such as very cold or very hot environments or aquatic environments with unusually high salt concentrations. Examples of the questions it may explore are: How do some animals flourish in the driest deserts, where temperatures are often high and freestanding water is never available? How do bacteria survive in hot springs, such as those in Yellowstone National Park in the western United States, that would cook most species? How do nematodes live in the soils of dry valleys in Antarctica? Physiological ecology looks at the special mechanisms that the individuals of a species use to function and at the limits on species imposed by the environment.
Behavioral ecology examines the ecological factors that drive behavioral adaptations. The subject considers how individuals find their food and avoid their enemies. For example, why do some birds migrate (see migration) while others are resident? Why do some animals, such as lions, live in groups while others, such as tigers, are largely solitary?
Population ecology, or autecology, examines single species. One immediate question that the subject addresses is why some species are rare while others are abundant. Interactions with other species may supply some of the answers. For example, enemies of a species can restrict its numbers, and those enemies include predators, disease organisms, and competitors—i.e., other species. Consequently, population ecology shares an indefinite boundary with community ecology, a subject that examines the interactions between several to many species. Species abundances vary both from year to year and across the species’ geographic range. Population ecology asks what causes abundances to fluctuate. Why, for example, do numbers of some species, typically birds and mammals, change perhaps threefold or fourfold over a decade or so, while numbers of other species, typically insects, vary tenfold to a hundredfold from one year to the next? Another key question is what limits abundance, for, without limits, species numbers would grow exponentially.
Biogeography is the study of the geographical distribution of organisms, and it asks questions that parallel those of population ecology. Some species have tiny geographical ranges, being restricted to perhaps only a few square kilometres, while other species have ranges that cover a continent. Some species have more-or-less fixed geographical ranges, while others fluctuate, and still others are on the increase. If a species that is spreading is an agricultural pest, a disease organism, or a species that carries a disease, understanding the reasons for the increasing range may be a matter of considerable economic importance. Biogeography also considers the ranges of many species, asking why, for example, species with small geographic ranges are often found in special places that house many such species rather than scattered randomly about the planet.
Community ecology, or synecology, considers the ecology of communities, the set of species found in a particular place. Because the complete set of species for a particular place is usually not known, community ecology often focuses on subsets of organisms, asking questions, for example, about plant communities or insect communities. A fundamental question deals with the size of the “set of species”—that is, what ecological factors determine how many species are present in an area. There are many large-scale patterns for example, more species are present in larger areas than smaller ones, more on continents than on islands (especially remote ones), and more in the tropics than in the Arctic. There are many hypotheses for each pattern. Ecological factors also cause the diversity of species to vary over smaller scales. For example, though predators may be harmful to individual species, the presence of a predator may actually increase the number of species present in a community by limiting the numbers of a particularly successful competitor that otherwise might monopolize all the available space or resources.
The questions above are generally applied to species at the same trophic level—say, the plants in a community, or the insects that feed on the plants there, or the birds that feed on the insects there. Yet a different set of questions in community ecology involves how many trophic levels there are in a particular place and what factors limit that number.
Conservation biology seeks to understand what factors predispose species to extinction and what humans can do about preventing extinction. Species in danger of extinction are often those with the smallest geographic ranges or the smallest population sizes, but other ecological factors are also involved.
Ecosystem ecology examines large-scale ecological issues, ones that often are framed in terms not of species but rather of measures such as biomass, energy flow, and nutrient cycling. Questions include how much carbon is absorbed from the atmosphere by terrestrial plants and marine phytoplankton during photosynthesis and how much of that is consumed by herbivores, the herbivores’ predators, and so on up the food chain. Carbon is the basis of life (see carbon cycle), so these questions may be framed in terms of energy. How much food one has to eat each day, for instance, can be measured in terms of its dry weight or its calorie content. The same applies to measures of production for all the plants in an ecosystem or for different trophic levels of an ecosystem. A basic question in ecosystem ecology is how much production there is and what the factors are that affect it. Not surprisingly, warm, wet places such as rainforests produce more than extremely cold or dry places, but other factors are important. Nutrients are essential and may be in limited supply. The availability of phosphorus and nitrogen often determines productivity—it is the reason these substances are added to lawns and crops—and their availability is particularly important in aquatic systems. On the other hand, nutrients can represent too much of a good thing. Human activity has modified global ecosystems in ways that are increasing atmospheric carbon dioxide, a carbon source but also a greenhouse gas (see greenhouse effect), and causing excessive runoff of fertilizers into rivers and then into the ocean, where it kills the species that live there.
In 1988 CBR received nonprofit status under Title 35, Chapter 2 of the Montana Codes Annotated known as the Montana Nonprofit Corporation Act. We also are a publicly-supported organization exempt from federal income tax under Section 501(c)(3) of the Internal Revenue Code. Donations, bequests and payments for research to CBR are tax deductible.
The board of directors of CBR also serves as its principal scientists. We have extensive experience conducting field research in the Northern Rocky Mountains and Northern Great Plains. Office and support facilities are provided as needed by our principal scientists. Our organization is open to participation by other biologists with concurrence by the board of directors. Additional information on CBR can be obtained from Peter Lesica at [email protected]
Stephen V. Cooper has a Ph.D. in Botany. Currently he is the plant ecologist for the Montana Natural Heritage Program. Steve has conducted vegetation classification studies throughout the Intermountain West and parts of the Northern Great Plains. His primary interests are conservation biology, vegetation classification and landscape ecology.
Joe C. Elliott has a Ph.D. in Botany. He has been a private consultant specializing in plant ecology and plant-animal interactions in Montana and throughout the western U.S. and Canada for the past 25 years. His primary interests are in bryology, disturbance ecology and plant succession.
Peter Lesica has conducted surveys for endangered plant species and consulted on natural areas identification and vegetation monitoring for public agencies and private conservation organizations throughout Montana for the past 20 years. He has conducted research on the genetics, demography and ecology of endangered plants.
Our team of marine scientists lead global research, partnerships and industry collaborations that explore how marine life responds to ocean change.
Research that forecasts future habitats
Our scientists are at the forefront of research on the impact of climate change to our marine environments. We use projected estimates of climate change – such as ocean acidification and temperature - as modified by local management – i.e. fishing and pollution.
One of our key concerns, is the rate of current change. Even if we maintain CO2 emissions at current levels - an unlikely scenario - CO2 concentrations in the atmosphere will increase by over 50 per cent in coming years. This increase will cause ocean acidification as more CO2 is dissolved into the world's oceans.
Our ongoing research uses combination of laboratory and field techniques. Lab studies can be carefully controlled, but the range of ecological interactions is quite limited. Conversely, field studies benefit from interactions within a natural community, but spatial and temporal variation in climate parameters do not behave exactly the same as future ocean conditions. Combining both approaches provide us with key learnings that help forecast future marine habitats.
Recovering lost baselines
Managing natural systems without knowledge of their previous state is like navigating without a map. The power of such research on policy development is hard to overstate.
Disappearing oyster reefs
Two hundred years ago our coast was an oyster reef. Due to population growth of coastal settlements in Australia, our scientists have been able to evaluate the collapse and elimination of native oyster reefs.
What did these reefs once provide nature? Our research explores the restoration of these environments and the food and habitat potential of these reefs for increased fish productivity and filtration capacity for clear coastal waters.
- Losing oyster reefs to history: Using the past to restore reefs for the future, eScience , Conservation Biology
Our research has discovered that seaweeds have been moving polewards for a long time. Our scientists have shown that continued warming may drive hundreds of species toward and beyond the edge of the Australian continent where sustained retreat is impossible. The potential for global extinctions is profound considering the many endemic seaweeds and seaweed-dependent marine organisms in temperate Australia.
Urban kelp forests
Thirty years ago, we had 'urban' kelp forests. Our recovery of the urban kelp baseline has enabled cross-government consensus on the need to improve water quality.
Previously, the absence of urban kelp was argued to be natural and water improvement unnecessary. South Australia now aims to reduce its release of nitrogen to our urban coast by 75 per cent.
Oysters are ecological superheroes
Oyster reefs fringed Australia’s shorelines and shaped our marine ecosystems for millennia.
These reefs can increase the abundance and diversity marine organisms through the habitat they create. Restoring our lost oyster reefs can not only help the environment, but strengthen commercial and recreational fishing, and increase tourism for coastal communities.
Oysters have a phenomenal ability to improve local water quality and decrease water turbidity, which allows sunlight to penetrate to the seafloor to enhances seagrass growth. Oysters also filter excess nutrients from the water which result from urban runoff, which helps avoid environmental catastrophes such as Algae blooms.
Their structures can reduce coastal erosion by attenuating wave energy and their shell building can provide a carbon sink, helping to slow the rate of climate change.
The role of oysters as ecosystem engineers is not dissimilar to the role of trees on land or coral reefs in tropical seas. In fact, oyster reefs are often considered the temperate equivalent of coral reefs.
Two hundred years ago, more than 1500 kilometres of South Australian coastline was covered in oyster reefs teeming with fish and home to thousands of marine species.
Today, oyster reefs in Australia are at less than one percent of their pre-colonial extent, and South Australia's native flat oyster (Ostrea angasi), is all but eradicated.