Conserving Biodiversity Mini-Reviews

  • What is Biodiversity and Why Conserve It?

    Biodiversity is a broad concept that refers to the “web of life”. It describes all of the organisms on Earth, the variety of organisms in an ecosystem and the genetic make-up of those organisms. Biodiversity is responsible for sustaining life as we know it — from producing oxygen, to pollinating our food sources and cleaning our water supplies.

    Relationships between organisms have evolved over millions of years into a complex network that functions in harmony with the Earth. All species within an ecosystem have a role to play, and the productivity and stability of any given ecosystem depends on the ability of all of the organisms to work together to maintain balance and ensure each other’s survival. 

    Since humans have inhabited the Earth, there has been a reduction in biodiversity and genetic diversity, yet our health and well-being are intricately tied to its survival. For example, our food sources require a vast range of native pollinators. Diverse ecosystems are responsible for purifying water and recycling nutrients. Our economic well-being relies on the availability of natural resources, such as timber and crude oil. Rainforests help manage the reduction of CO2 to regulate our climate. Fifty percent of modern pharmaceutical products used in developed countries are derived from plants, animals and microorganisms, and this number increases to 80% if you take into consideration traditional medicines used across the globe. Biodiversity enriches our cultural and recreational experiences: it pleases the senses and gives us the opportunity to exercise, whether it be hiking, bird watching or boating on a lake. 

    Ecosystems are vulnerable to collapse, and a loss of biodiversity makes them more susceptible to disease and sudden environmental changes. It renders the ecosystem less adaptable. 

    Humans have caused rapid changes to ecosystems and a decline in biodiversity. Habitat destruction, particularly in biodiverse-rich tropical regions, is the primary cause of an accelerated level of extinction of many species. Upstream of habitat destruction is overpopulation, which has led to an unsustainable level of resource consumption. Downstream of habitat destruction is climate change — to which the burning of fossil fuels consequently warming the atmosphere, the destruction of forests that play a critical role in regulating climate, ocean acidification and changes in plant morphology all contribute. Other factors, such as the accidental and deliberate introduction of non-native species to an ecosystem and overfishing of our lakes and oceans, are also significant threats to biodiversity.
    One key challenge we face is to better understand the complexity of all biodiversity and the network of interactions that occur within ecosystems — this knowledge will help us to better evaluate the threats. Some of the most significant disruptions to ecosystems have been the result of a lack of awareness of the complexity within that ecosystem. Our attempts to control an ecosystem for human benefit has, in many cases, been disastrous.

    We also need to expand protected areas of land and ocean, with a desire to both preserve ecosystems and benefit from what they have to offer. Precious resources must be carefully utilized, while fully considering the implications.
    Biodiversity is declining, and human population is growing exponentially; however,  we are now gaining tools and the necessary knowledge to protect our planet for future generations. Scientific and community involvement is continually expanding, which has the potential to lead to policy changes designed to conserve biodiversity.

  • Choking the Oceans with Plastic

    By the year 2050, it is predicted that the Earth’s oceans will be home, by weight, to more plastic than fish. Eight million metric tons of plastic trash enters the sea every year. This plastic collects in all the oceans on Earth in large, circular currents, or gyres. The largest gyre has been coined The Great Pacific Garbage Patch. Many estimates are made to convey the immensity of this patch — it is 1.6 million km2 or 618,000 miles2, or three times the size of France. In other words, it is big!

    Ocean debris consists of large and small pieces of plastic; however, the predominant contaminant is tiny confetti-sized pieces of plastic that have been photodegraded by the sun. This fog of particulate easily enters the food chain, and approximately 12,000 to 14,000 tons are ingested by fish and invertebrates each year, threatening the biodiversity of ocean life.

    Much of the media coverage focuses on sea turtles, birds, seals and other marine animals entangled in, or ingesting, the trash. However, the plastic problem also extends to chemical pollution and its worrying effect on the reproductivity of various marine organisms. Previous research on plasticizers, such as bisphenol A (BPA) and phthalates, has shown that they induce endocrine toxicity and reproductive alterations. Furthermore, plastic polymers attract polychlorinate biphenyls (PCBs) and other toxic chemicals.

    Pacific Oysters (Crassostrea gigas) that were experimentally exposed to polystyrene microparticles at concentrations estimated for the water-sediment interface (a typical oyster habitat) produced fewer and smaller egg cells, less-mobile sperm and slow-growing offspring1. Additionally, exposure to nanoplastics caused green algae (Scenedesmus obliquus) to exhibit 
    reduced growth and chlorophyll concentrations, and a small planktonic crustacean (Daphnia magna) to present reduced neonate body size and increased malformations2.

    Many marine organisms, such as bryozoans and crustaceans, are known to colonize floating wood or seaweed, using them as a raft. Now, non-rafting, invasive species, such as coral pathogens, are using plastic debris to travel to, and damage, new ecosystems. Also “hitching a ride” are communities of microbes that are vastly different than those found in the surrounding seawater, for example, members of the genus Vibrio, which is a human pathogen. A marine insect, Halobates sericeus, that typically lays its eggs on natural rafts, such as shells and bird feathers, has now been observed laying eggs on plastic debris. The long-term effects of this have yet to be determined. 

    In the first decade of this century, more plastic was generated than ever before — and every piece produced is likely still here on the planet. Intervention at the source of this problem, specifically a reduction of single-use plastics, clearly needs to be promoted. However, we can find a glimmer of hope in ongoing efforts — massive trawling clean-ups, GPS tagging of trash to model its movement, materials scientists turning their attention to more environmentally-friendly packaging, large companies reducing their waste and consumers who are making more informed decisions every day. 

    (1) Sussarellu, R., et al (2016) PNAS, 113, 2430–2435.
    (2) Besseling, E., et al (2014) Environ Sci Technol, 48, 12336–12343.

  • Habitat Fragmentation

    Habitat fragmentation occurs when a continuous habitat is disrupted and divided into smaller habitats that are physically isolated from each other. It carves the environment into patches and divides plant and animal populations. Fragmentation can occur when a forest is disrupted for urban development or agricultural purposes, following a forest fire, or by the addition of roadways through a previously continuous habitat. The result is that the number of plants and animals in the fragments decreases, and the further apart the fragments are, the greater the loss in species diversity and genetic diversity. This increases the likelihood of species becoming extinct, as they are less able to deal with environmental changes or disturbances. 

    Furthermore, “edge effects” are observed in fragmented habitats. Edge effects refer to the contrast between adjacent habitats that can hinder the safe travel of species. When the contrast is great, for example, with suburban development, abiotic factors, such as an increase in sunlight, wind and temperature are observed. These factors influence which plants and animals live near the edge.  A sharp contrast between habitats affects the safety of animals as they move around to forage for food and water. It also makes seasonal migration more dangerous. If an animal has to leave its core habitat and enter a more hostile environment, they become more vulnerable to attack by a predator.

    In a fragmented forest, such as the Middle Magdalena Valley in Colombia, the Brown Spider Monkey no longer has a continuous canopy to move around — 80% of its habitat has been cleared for farmland and cattle ranches. Spider monkeys have a prehensile tail that acts like a fifth limb and gives them the appearance of a spider; they require large tracts of undisturbed forest due to their large body size. 

    While the monkeys rely on the forest, the forest also relies on the monkeys to regenerate. Spider monkeys disperse the seeds of approximately 100 tropical plants through ingestion of the fruit in one location, and then elimination of the seeds in a different part of the forest. Spider monkeys defecate 13 to 17 times a day, and this represents the dispersal of hundreds to thousands of seeds. Many of the seeds that they disperse belong to the dense, hardwood trees that are the most effective in eliminating carbon dioxide from the atmosphere.

    Habitat fragmentation limits the distance that can be traveled safely by the spider monkey, and consequently, the area of seed dispersal. Fragmentation is causing a decline in the spider monkey population, which causes concern regarding the future of the forest. In an effort to prevent this, researchers observe the monkeys and are directed to their feces by dung beetles. They collect, wash and categorize the seeds in order to predict which species of plants will be dispersed, the quantity of each species, and to see if there is a pattern between the type of seeds dispersed and the monkey’s gender or age. They then plant the seeds in degraded areas that could potentially provide continuity, a nature corridor, between fragmented areas. 

    It is hoped that efforts to restore the continuity of the Middle Magdalena Valley will allow spider monkeys to again move freely around the canopy and carry out their crucial role in preserving the biodiversity of the forest. The tale of the spider monkey demonstrates how habitat fragmentation effects not just a single species, but an entire ecosystem.

  • Microbes Cleaning Up Our Mess

    In a world where we consume 90 million barrels of oil every day, spills at oil rigs are inevitable. In fact, according to the U.S. Environmental Protection Agency, there are 70 spills per day — most are insignificant. However, in 2010, 4.9 million barrels of crude oil spewed from the BP Macondo well, located in the Gulf of Mexico, over a period of 87 days. This unfortunate event was termed the Deepwater Horizon spill, and is the largest marine oil spill in history. 

    Extensive damage to marine ecosystems resulted from the spill, including heavy oiling of four of the five endangered, protected turtle species that live and breed in the Gulf of Mexico. Additionally, many marine mammals that live in the Gulf of Mexico experienced reproductive failure and organ damage following the spill.

    Large fire booms were used to surround the slick and burn off approximately 5% of the oil. Chemical dispersants broke 40% of the oil into tiny droplets suspended under the ocean surface in a plume that measured 161 km (100 miles) long. Scientists were surprised to find that the clean-up occurred at a much faster rate than predicted, because it was aided by hydrocarbon-degrading microorganisms. Further, the use of chemical dispersants, while controversial due to their toxicity, actually aided this process by generating smaller size oil droplets (and a larger surface area) for what was estimated to be a bloom of 100 sextillion microbes.

    Background levels of oil exist in many marine ecosystems due to slow seepage from underwater reservoirs. Luckily, a well-established community of bacteria capable of degrading the compounds contained in oil is also present. The short doubling time of these bacteria and their ability for horizontal gene transfer allow for the rapid proliferation of this diverse community following a spill. These hydrocarbon-degraders use the oil as an energy source. Each microbe population has a distinct set of hydrocarbon degradation genes with specificity for breaking down different constituents of the oil, and they proliferate at different time points following a spill, depending on their specificity. Following degradation of the oil, the microbes stop rapidly dividing and are consumed by other organisms further up the food chain.

    Oil from the Deepwater Horizon spill washed into wetlands and marshes all along the northern Gulf of Mexico, and heavily oiled a coastal plant named Spartina alterniflora, commonly known as smooth cordgrass. Cordgrass is a foundational plant that stabilizes land and minimizes erosion. Scientists found that in addition to the presence of oil in the plant tissues, the composition of endophytes living symbiotically in cordgrass roots showed an increase in oil-degrading bacteria. It is well known that these bacteria can degrade oil in oceans and on beaches, but what researchers are trying to establish is whether the bacteria continue to process the oil inside the plant tissue, and if so, which bacteria are most efficient at accomplishing this. Scientists are also exploring whether the plant roots can deliver hydrocarbon-degrading bacteria to the buried oil in the marsh. This raises the possibility for bacterial inoculation of cordgrass, which can then be planted and used to help restore coastal areas exposed to an oil spill.

    The Deepwater Horizon oil spill was catastrophic to marine habitats. What resulted from the close study of these habitats was the identification and understanding of a diverse community of microorganisms, which are highly evolved to deal with their specialized environment and when necessary, can clean up the mess we make. Yet another reason to appreciate microbes.

  • Taking Molecular Tools to the Jungle

    Climate change, habitat destruction and pollution are causing accelerated species extinction, particularly in tropical ecosystems. Extinction rates that were one species/million/year have increased to 100–1,000 species/million/year. Unfortunately, most of these species have yet to be identified. With an incomplete understanding of species diversity, it is difficult to know where to direct conservation efforts and resources. This knowledge gap has prompted an urgency to catalog as much biodiversity as possible, as quickly as possible. 

    DNA barcoding is a standardized method of identification that utilizes a short region of the mitochondrial cytochrome c oxidase I (COI) gene in animals (and various other sequences in plants, fungi and protists) to document species quickly and inexpensively. The mutation rate of mitochondrial DNA over relatively short evolutionary periods reflects the diversity between species. It should be noted that barcoding is distinct from, and does not supersede, specialized taxonomic identification of subtle anatomical differences between species, but the combination of molecular and morphological data improves the characterization and delimitation of species. 

    Biologists have used barcoding in large projects, such as the Census of Marine Life, a 10-year study that assessed the biodiversity and distribution of the Earth’s aquatic ecosystems. This study identified 190,000 species, including 6,000 potentially new species. Scientists discovered new habitats, symbiotic relationships and microbial biospheres. They found species that are in decline and new examples of ecosystem resilience.

    The colossal effort to document all of the organisms on our planet before they become extinct is a race against time, and it presents researchers with logistical hurdles related to cost and sampling. First, the countries with the greatest biodiversity, such as tropical regions, are often the countries that do not have abundant research resources dedicated to conducting this work. Second, the laws that govern the international transportation of biological materials from biodiverse regions to resource-rich areas can cause delays that compromise sample integrity or prevent sample transportation altogether. 

    These limitations have necessitated the development of small, portable sequencing tools and technologies that can be used on-site. Conservation scientists can now transport a small DNA sequencing platform, PCR thermocycler, microcentrifuge, reagents and a laptop in a backpack to remote regions, where they can rapidly and cost-effectively extract DNA, amplify and sequence barcodes. This process can be carried out within 24 hours of sample collection, accelerating data acquisition significantly.

    Collecting genetic information at the source allows easy documentation of information regarding species health, geographic distribution, hybrid zones, as well as the identification of new species. Rapid access to this information can help focus conservation efforts, and guide the allocation of appropriate resources when planning for species conservation. Geographical areas of highest biological value can be identified and protected, and laws can be implemented to preserve the most endangered species.

    Documenting organisms in their habitats is a less invasive, expedient method that can assist conservationists in protecting our planet’s immense, yet diminishing, biodiversity.

  • The Downstream Effects of Overfishing

    Fishing has been a mainstay throughout the history of civilization. However, the methods, equipment and extent of fishing have drastically changed in order to feed an overpopulated world. As a result, we are rapidly depleting our oceans of what was once thought to be an endless supply of fish. What is not as readily understood is that gaps in the food web created by overfishing certain species, and the currently-used industrial fishing methods, such as bottom trawling, are destroying entire ecosystems.

    The global fishing industry is worth nearly 250 billion dollars per year, which equates to 90 million tons of fish. Eighty percent of commercial fish stocks have been declared overexploited, yet this is not reflected in the variety of fish available in local markets. This is due to the fact that industrial-scale fishing efforts have moved further offshore and to deeper depths of the ocean to find new sources. “Super trawlers” the size of ocean liners use probes, radar, sonar, helicopters and spotter planes to hunt down marine life. Nets that can measure 40 km long catch targeted species of fish, as well as non-targeted species (“bycatch”), such as seabirds, turtles and dolphins, which are thrown back into the sea, often dead or dying.

    Modern fishing techniques completely devastate ocean habitats. Bottom trawlers drag nets along the ocean floor, destroying rich, complex ecosystems and communities of invertebrates on the sea bed as they comb for scallops and shrimp. They leave behind a barren landscape of sand and gravel. The disregard for entire ecosystems also extends to coastal areas where mangroves are destroyed for shrimp fishing, leaving local coastal communities without storm protection, a natural form of water filtration, or nursery habitats for marine life.

    Large deep-water fish, such as Bluefin tuna, are commercially very valuable and are aggressively targeted. They take longer to reach sexual maturity and do not reproduce as often. They are unable to replenish themselves fast enough to meet demand and consequently, younger fish that have not yet reached spawning age are targeted. Depleting the large and predatory fish significantly affects food web dynamics. The smaller, more resilient fish remain, and eventually, the range of fish observed are smaller and less diverse. 

    The Aleutian Islands, off the coast of northern Alaska, saw the effects of overfishing on an entire ecosystem when baleen and sperm whales were overfished, removing a food source for Orcas. This forced the Orcas to feed on less calorie-rich animals, including otters. The primary prey of otters is sea urchin, which in turn, feed on kelp. The decline in otters led to a drastic increase in kelp grazing by urchin, and the destruction of kelp forests. When nesting fish do not have the protection of kelp, their larvae are vulnerable to predation. In the case of the Aleutian Islands, this ultimately led to the collapse of the fishing industry.

    Overfishing affects the balance of marine ecosystems and the livelihood of millions of people. As awareness grows, steps are being taken to protect our oceans. Marine reserves, or “no fishing” zones are being established so that fish stocks can recover. Organizations such as the Marine Stewardship Council certify sustainably caught fish, indicating to conscientious consumers the products that support restoration of marine life. Supermarket chains are taking on a vital role offering sustainably caught seafood to customers. These measures give hope that with even greater awareness we may just be able to restore this essential resource.

  • The Effect of Dams on River Systems

    Dams have substantially contributed to urban development and industrialization. Historically, they were considered a sign of a thriving civilization, providing hydroelectricity, irrigation, flood control and a supply of water to nearby towns. However, they come with an environmental cost, and aging dams have limited capability to meet the energy needs of a modern world. 

    Essentially, dams obstruct the flow of rivers — there are 84,000 dams in the USA that are three feet high or greater, blocking 600,000 miles of river. They also have a profound effect on the river ecosystem. Upstream of a dam, the water is stagnant. Sediment, rocks and wood that would normally flow downstream and shape the landscape, build up and affect the coastline ecosystem. Weeds and algae proliferate and reservoir depth results in colder water, which in turn reduces the amount of oxygen and changes the nutrient composition for marine life. The dam effectively turns the river into a lake.

    The Elwha and Glines Canyon River Dams were built on the Elwha River, which mostly lies within Olympic National Park in Washington, USA, in 1913 and 1927, respectively. They were built in order to harness the power of the river to generate electricity. At the time, they energized economic growth in the region, but 100 years later they provided only a minimal amount of the electricity needs of the district. The cost of keeping the dams outweighed the benefits, and they were removed between 2011 and 2013. The removal of the dams was two decades in planning. This gave scientists the opportunity to document the surrounding ecosystem before and after the demolition, so that the feasibility of other dam removal projects could be assessed. 

    The two dams blocked wild salmon runs, and this had a profound effect, not only on salmon numbers but also on the surrounding ecosystem upstream of the dam. Salmon are a keystone species. They thrive and grow on marine nutrients in the sea, and when they return to the river and travel upstream to spawn, they transport valuable nutrients to the wildlife. If they die or are killed by other animals in the ecosystem, such as bears, otter and eagles, these nutrients are distributed into the surrounding vegetation. When the salmon disappeared, so did the animals that relied on them for survival.

    The Elwha River was choked with 33 tons of sediment — dismantling the dams reshaped 13 miles of the Elwha River and expanded the river delta at the Pacific Ocean. Wood and sediment reshaped the shore — beaches, kelp beds and eelgrass beds flourished. Willows were soon thriving by the river. Moss grew and created a microclimate for other plants. The dams had prevented Pacific Salmon from reaching 90% of their habitat, and now they were returning to parts of the river that had not seen salmon in 100 years. 

    This massive project has provided a wealth of information for ecologists. Not only do we better understand the effects of putting dams in place, but we can now predict the outcome of future dam removal projects. Not every dam is obsolete, but as the outdated and unsafe dams are coming down, the flow of rivers and valuable ecosystems are being restored.

  • The Importance and Fragility of the Amazon Biome

    The expanse and biodiversity of the world’s largest rainforest is hard to fathom. The Amazon covers almost 7 million km2 (2.7 million miles2) in the northern region of South America. The Amazon River flows for 6,000 km (3,700 miles) from Peru, across Brazil, and into the Atlantic. The uniqueness of the biodiversity in the Amazon is matched nowhere else on Earth. It is home to one in 10 species on our planet, and 25% of all terrestrial species. There are 400 billion trees that belong to 16,000 different species. In Brazil alone, there are 100 different species of monkeys; nine new species have been discovered in the last decade. Dozens of plant and animal species are still being discovered every year. 

    Plant and animal species form intricate, cooperative relationships with each other that have evolved over millions of years. In the Amazon, adaption is the key to survival. For example, the Brazil nut tree cannot be cultivated outside of the Amazon because of its incredibly specialized, mutualistic relationship with large-bodied bees strong enough to open its petal and pollinate other flowers, the agouti who disperses the Brazil nut and sustains a healthy population of Brazil nut trees, and the scent of a specific forest-dwelling orchard that male bees use to attract females.

    The Amazon is often referred to as the lungs of our planet — the trees help to regulate Earth’s atmosphere by “breathing” in carbon dioxide and releasing oxygen, thereby keeping the Earth cooler. It is estimated that 40% of human-made carbon dioxide is cleared by rainforests. 
    The Amazon regulates local and global weather patterns by absorbing heat and releasing water vapor via photosynthesis into the atmosphere, seeding the clouds with rain. The Amazon River carries 20% of the world’s water to the sea. 

    Unfortunately, the Amazon is under constant threat by humans who are logging and farming the land, mining its resources, damming its rivers, and destroying indigenous lands and cultures. Deforestation has the Amazon at the “tipping point”, with just over 80% of trees remaining. This drastic reduction in the number of trees reduces the amount of moisture released into the atmosphere, thereby jeopardizing the rainfall patterns and the replenishment of the rivers. The act of cutting down the trees releases stored carbon into the atmosphere, contributing to global warming. The immense plant diversity of the rainforest is being replaced with monocrops, such as soy or palm, and the animal diversity replaced by a single species, such as grazing cattle.

    Substantial efforts are being made to protect large swaths of forest. In Brazil, armed guards protect against illegal logging, and while this activity has decreased from 25,000 km2/year (15,500 miles2) to just over 6,000 km2/year (3,700 miles2), it is almost impossible to guard an area that is larger than India. Governments are expanding protected areas — for example, the Colombian government expanded protection around Chiribiquete National Park to incorporate an area that is home to three uncontacted and isolated tribes and more than 200,000 paintings of pre-Columbian art. Further, technology is being carefully introduced to contacted tribes to give them the control to map and manage over 70 million acres of ancestral rainforest. 

    Protecting the entire forest from human destruction is a seemingly impossible feat. However, global awareness of the significance of this rainforest, its biological, cultural and economic riches, can turn the tide and ensure its survival for generations to come.

  • The Importance of the Top Predator

    The collapse of an ecosystem, if we are not observant, can take decades to fully realize and understand. In the mid-1990s, the banks of the Lamar River in Yellowstone National Park, USA, were eroded, streams had widened, willow shoots that had previously flourished by the river in the 1920s were nonexistent, aspen trees were not regenerating and beavers were scarce. 

    How is it that the collapse of this ecosystem could be the result of an event that occurred in the 1920s?

    The case in Yellowstone National Park began as an investigation into the disappearance of aspen trees. Scientists examined the age of the remaining trees by drilling into the cores and establishing age versus diameter relationships. They discovered that the aspen tree had not regenerated in the past 70 years, and by back-dating, it was realized that this 70-year hiatus correlated with the disappearance of the wild wolf from Yellowstone. The downstream effects that occurred as a result of the sudden absence of the wild wolves highlights the complexity of a balanced ecosystem.

    A top predator, also known as an apex predator, is at the head of the food chain. In the early 1900s, Yellowstone’s top predator, the wild wolf, was viewed as a threat and was hunted until it was completely eliminated from 
    the park by the 1920s.

    Pieces of the puzzle started to fit together when scientists examined the effect of unchecked population growth of elk, the primary prey of the wild wolf. Vegetation, including aspen and willow tree saplings, were overgrazed by the elk. The riverside willow had provided material for beavers to build their dams, and in turn, the dams provided more water and nutrients for growth of the riverside vegetation. Additionally, the beaver’s protective dams had tempered the seasonal changes in the river flow. With no material to build dams, the beavers also disappeared.

    In 1995, in a highly controversial move, 31 wild wolves were relocated from Canada to Yellowstone. Their movement and behavior were observed as they hunted elk and deer. The elk carcasses not only fed the wolves, but also coyotes, ravens, magpies, eagles and finally, insects.

    The elk were also tracked, and it was observed that they avoided the gorges and valleys where they were easy prey. With less elk and deer grazing on willow and aspen, the long-gone vegetation started to regenerate; more berries and insects followed, and then various bird species. Beaver families moved back into the area and used the willow to build their dams, which created a habitat for otter, muskrat and reptiles. The wolves also killed coyotes, and so the rabbit and mice populations grew, which fed hawks, foxes, badgers and weasels. The regeneration of the riverside vegetation stabilized the river banks against erosion, and subsequently, the rivers narrowed and became more fixed in their course. Pools began to form, creating habitats for other organisms. 

    The Yellowstone example gives insight into the trophic cascade that can result from removing a key organism from a balanced landscape and ecosystem, and while a top predator kills certain species, the downstream effects give life to many other species. The regeneration of this amazing ecosystem shows the incredible ability of a vast biome to restore itself, and the lessons learned here could lead to better predator management decisions in other locations.

  • The Race to Save the Reefs

    Coral reefs occupy less than 1% of Earth’s ocean floor; however, they are home to 25% of all marine wildlife. Coral is the central infrastructure of reefs, and the trees of an underwater forest, which provides microhabitats, shelter and breeding grounds for thousands of species.

    There is an incredible network of collaborative relationships between thousands of reef species that underpin all life in this rich habitat, and each of the residents have a role. First and foremost, coral is made up of millions of polyps that house microalgae (Zooxanthellae), which photosynthesize and provide 90% of the coral’s food. There is also an abundance of unrelated animals hunting together to share a meal, cleaning and protecting each other, recycling waste and defending the reef in a reciprocally altruistic fashion.

    Coral is a keystone species, meaning it has a crucial role that no other species in its ecosystem can perform. This role is essential for the survival of the ecosystem, and therefore, if it becomes threatened, it jeopardizes the entire ecosystem. 

    The threats to the world’s reefs include pollution, infectious disease, overfishing and climate change. Rising sea temperatures cause the polyps to eject the microalgae. Without its food source, the coral becomes photobleached and subsequently leaves all of the reef species without their habitat.

    In the past 30 years, more than half the world’s corals have been affected by bleaching, and the intervals between bleaching events have become shorter, leaving the coral without time to recover. Scientists have concluded that if water temperatures continue to rise at the current rate, all coral reefs will die by the turn of the century. 
    Can these fragile ecosystems be restored? A glimmer of hope comes from the pioneering work of marine biologists who are manually growing and planting corals that can tolerate higher temperatures and ocean acidification. 

    Researchers break slow-growing, massive reef-building corals into small pieces, which stimulates rapid healing and growth. The corals are then outplanted back onto the damaged reefs. However, this clonal method of reproduction is not enough; genetic diversity comes from sexual reproduction, and luckily, corals reproduce both asexually and sexually.

    Biologists are also collecting eggs and sperm from colonies of Brain coral during spawning events that occur typically one week after a full moon. Swarms of butterflyfish direct the divers to coral that is about to spawn. They collect the sperm and eggs in tents and fertilize them in the lab. The reproductive success rate is approximately 0.2% in nature, but in the lab, it is upwards of 90%.

    Other marine biologists are breeding “super coral” by crossing the most robust species of coral in the lab and then transplanting them back onto the reef, where they can hopefully withstand the current stresses that are leading to their decline.

    It remains unclear at this point whether the scale of assisted coral transplantation can match that of coral loss, and ocean warming continues to pose a threat to these recovery efforts. Regardless, the passion of these coral enthusiasts and marine biologists to save the Earth’s coral reefs is genuinely inspiring.

  • The Ripple Effect

    The removal or extinction of one species in an ecosystem can create gaps in the food chain. This gap can cause a “ripple” throughout the ecosystem, sequentially threatening different species due to disturbances in their food source, habitat or specialized relationships with other species.

    In the late 1970s, the Large Blue Butterfly (Maculinear arion) was declared extinct in Britain. This beautiful, rare species was highly sought after in the 19th century by butterfly enthusiasts, and consequently, its numbers declined. Conservation efforts to fend off collectors and preserve Large Blue colonies began in the 1920s, and part of this effort included the removal of grazing sheep.

    The Large Blue has a complex, predatory relationship with the red ant, Myrmica sabuleti. The butterfly lays its eggs on the leaves of wild thyme plants, which is where the caterpillar feeds before eventually dropping to the ground. It deceptively hunches its body so that it appears to be the size of the ant larvae and produces a pheromone which mimics that of the red ant grub. The pheromone attracts the red ant, fooling it into adopting the caterpillar and transporting it to its underground nest where it feeds on ant larvae. The caterpillar will only survive in the nest of the Myrmica sabuleti; all other red ant species in this environment will recognize it as an impostor and kill it. The caterpillars go as far as to mimic the sound of the Queen ants so that the worker ants will feed and clean them. At least 230 ant larvae and 354 ant workers are required to guarantee the survival of just one Large Blue Butterfly. 

    Researcher Jeremy Thomas carefully observed the last surviving colony of Large Blue Butterflies from 1972 until it disappeared in 1977. He pieced together the butterfly’s intricate, exploitative relationship with the red ant and also concluded that a ripple throughout the ecosystem began with the seemingly minor modification of removing grazing sheep. This habitat felt a ripple when the grass grew longer and the soil temperature decreased by just 1 or 2°C, resulting in an unsuitable habitat for the temperature- and humidity-sensitive red ant. The red ant population plummeted, and this left its predator, the very visible and appreciated Large Blue, without its food source. The Large Blue’s lifecycle was no longer viable now that the incredibly specialized environment in which it had survived, was gone.

    A habitat recovery project involved re-establishing grazing animals on over 100 sites. Large Blue larvae were imported from Sweden and placed in red ant nests in the 1980s and 1990s. A period of optimization of grazing conditions was required before the red ant, and then the Large Blue, thrived.

    In recent years, the number of insects in Britain and Europe has declined more than plants and birds. Thomas’ findings highlighted the need to focus on the ecological conditions that cause insect numbers to decrease and to integrate their needs with modern land use. The intensive research project to restore the habitat of the Large Blue was the first effort to reverse the decrease in numbers of an endangered insect species, which has helped other declining insect populations, and hopefully will help to prevent other such “ripple effects”.

  • The Threat to Pollinators

    In 2006, beekeepers were reporting huge losses in their honeybee colonies — 30-90% colony loss, up from 15-20% in previous years. This phenomenon was termed Colony Collapse Disorder (CCD), because worker bees would leave their colony, never to return, ultimately causing the entire colony to collapse.

    It has since been generally agreed upon that many different environmental factors can cause CCD. Farming practices no longer include cover crops of clover and alfalfa— which are highly nutritious for bees — and the land is now used to grow large monocrops. Infection with Varroa mite leaves the bees immunocompromised and more susceptible to infection with other diseases. Overuse of neurotoxic pesticides (specifically, neonicotinoids) causes death, or in lower doses, disorientation that affects the bees’ ability to fly back to their hive. 

    Furthermore, honeybees are often treated like livestock and are overworked. They are shipped from farm to farm to pollinate vast monocrops, without time to rejuvenate before they are moved on to the next crop that requires pollination. Additionally, like any managed livestock, there are high levels of disease among honeybee colonies, because of the density in which they are kept, and pathogen spillover to other species of wild pollinators is common.

    The observation in the past couple of years is that these losses are beginning to plateau. However, this could be due to more controlled breeding of honeybees to meet agricultural demands rather than addressing the environmental triggers. Did we avoid a catastrophic extinction, or is there a broader threat that remains for the health of 
    our pollinators? 

    There are 20,000 species of bees in the world responsible for pollinating one third of the world’s crops, which equates to two to six billion dollars in global agriculture every year. Not only do our fruits and vegetables rely on pollination to eventually make it to our table, but bees also pollinate alfalfa hay, which feeds farm animals. 
    Pollination of 50% of crops worldwide requires the services of not just honeybees, but a whole host of wild pollinators, including butterflies, wasps, beetles and many other bee species. Truly efficient pollination requires all of these pollinators working together — at different times of the day and on crops best suited to their abilities. For example, tomato plants are either wind pollinated or require particular strong-winged bees, such as bumblebees, to perform “buzz pollination”, or sonication, whereby the bee vibrates at a high frequency to release the pollen. Loss of these pollinators means that in some farming areas, tomato plants need to be hand pollinated.
    While there has been much discussion about protecting honeybees, we should in fact be thinking about the well-being of ALL the crop pollinators. Being mindful about farming practices, pesticide use and habitat disruption can help to ensure the protection and proliferation of these important workers.

  • Whisky and Oysters

    Oysters are essential members of a diverse marine ecosystem because of their specific roles in contributing to biodiversity. They purify water by pumping it through their gills — obtaining food for themselves and filtering plankton and chemical contaminants from the water. Additionally, generations of oysters settle on top of each other, forming a reef of sorts, that provides habitats for other marine organisms, such as crabs. 

    While oyster reefs all over the world are threatened due to overfishing, in one protected location in northeast Scotland, there is a university, a marine conservation society, and a whisky distillery all striving to restore a long-lost oyster habitat. 

    The Dornoch Firth is a large and complex estuary that has been designated both a Special Protection Area (SPA) and Special Area of Conservation (SAC), because it is one of the northern-most estuaries for migrating and wintering birds. White sandy beaches at the mouth of the estuary lead to salt marshes, sandflats and mudflats that support an incredibly diverse plant and animal environment, including breeding osprey, waders and wildfowl, seal, dolphins, otters and mussel reefs. 

    The Native European Oyster thrived in the waters of the Dornoch Firth for over 10,000 years, until it was overfished and disappeared completely just over 100 years ago. 
    Glenmorangie Distillery is picturesquely situated on the banks of Dornoch Firth, producing single malt whisky for the past 175 years. In 2014, Glenmorangie pioneered a project to reduce their environmental footprint. The whisky distillery teamed up with Heriot-Watt University and the Marine Conservation Society in a partnership called DEEP (Dornoch Environmental Enhancement Project) to make some drastic changes to the water quality, re-introduce the Native European Oyster, and set a precedent for the re-establishment of disappearing reefs worldwide. 

    The DEEP project had two major initiatives. First was the introduction of an anaerobic digestion plant that purifies 95% of the by-products of whisky distillation that were previously released into the Firth. The remaining 5% consists of mostly organic compounds, such as barley, which is used as food by the oysters that then go on to further improve the water quality in the firth.

    Next was the re-establishment of the Native European Oyster reef. Following an initial small scale exploratory step, twenty tons of waste mussel and scallop shells were laid down to stabilize the sediment and give the oysters a surface on which to grow. Divers then laid down 20,000 Native European Oysters in an area that covers 40 hectares of the firth. Their hope is that the oyster population will grow to 200,000 in three years, and then four million after five years, generating a fully sustainable oyster reef. 

    Ultimately, the introduction of an anaerobic digestion plant and the re-introduction of the Native European Oyster reef will drastically improve the water quality in Dornoch Firth. In turn, this supports all of the other organisms that form the diverse marine ecosystem there. A picturesque landscape for a renowned distillery on the edge of an ecosystem teaming with bird, plant and marine life, is a victory for both whisky connoisseurs and for the conservation of biodiversity.

  • Backyard Biodiversity

    Habitat loss due to human development is the primary cause of diminishing biodiversity. Living in urban areas furnished with exotic plant species and manicured lawns fragments ecosystems, and it leads to a disconnect between our everyday activities and the unintended consequences that they have on nature. As a result, biodiversity is often treated as a commodity. But, there are simple things that can be done to help preserve biodiversity — starting with learning how to share our living space with the organisms that are so essential to our existance.

    Whether you live in a house with a yard or an apartment with a balcony, you can contribute to creating continuity in nature by bringing back the plants that were once naturally found there — this supports the safe travel of animals between core habitats as they search for cover and forage for food and water. A “wildlife corridor” that incorporates many vegetative layers and provides food, water and shelter will be more resilient to perturbations.

    Native plants are adapted to local conditions and are easier to maintain, particularly in arid regions, so leave the native plant species undisturbed. Landscape using native trees and vegetation, and remove invasive plant species. Also, plants protect themselves by producing distasteful or toxic chemicals, and native insects that have evolved with specific native plant lineages develop a tolerance for and only eat, these plants. Non-native plants produce different chemicals, which can be detrimental to the native insects. Systemic pesticides such as neonicotinoids should always be avoided, as these pesticides persist in all parts of the plant and can poison the pollinators. 
    Fragmented habitats and pesticides leave pollinators malnourished. However, nectar from a variety of native flowering plants that bloom throughout the season attracts many pollinators — birds and beneficial insects — which keep the pests at bay without the use of pesticides. In addition to nectar-producing flowers, plants that feed butterfly larvae are also important.

    Leaving wooded areas to age and decompose on their own offers significant benefit to many species. A dead tree may provide shelter or a perch for woodpeckers and other birds, frogs and lizards. A pile of rocks or logs can serve as a home for chipmunks or toads. Decomposing logs provide a habitat for insects and worms to thrive, and nutrients for the soil, encouraging plant growth. Insects and worms then pass the energy from plants to non-plant eating animals further up the food chain, such as spiders, birds and amphibians. 

    A tree hollow takes up to 150 years to naturally develop and is essential for nesting and breeding. Nesting boxes for birds, bees and bats can help alleviate the shortage of hollows. A birdbath, pond, or a carefully planned rain garden will attract birds and aquatic wildlife, such as frogs and dragonflies.

    In addition to our own backyards, one can consider getting involved with regional ecological restoration efforts. Good places to look for opportunities are land trusts, wildlife foundations, native plant societies, government agencies (e.g., Forest Service, Fish & Wildlife), and environmental organizations. Protecting habitats before they have been damaged is the best form of biodiversity conservation and is most successfully implemented by government regulations. 

    As human development and urban expansion continues to increase, we are outcompeting other species for space on Earth. Educating ourselves on how we can co-exist and provide wildlife with water, food, cover and a safe place to raise their young in our own surroundings can go a long way in conserving biodiversity.