January 19, 2017
People who know me well know that I listen to a lot of podcasts. It helps pass the time while I’m commuting by bike or walking my dog or going on lengthy summer rides. Every so often, some strike me as especially appropriate for the community of restoration specialists, conservationists, biologists, ecologists, regulators, educators, and others we know read our blog. Here are seven episodes that we think our readers might especially enjoy:
As a note: The Story Collider is a podcast specifically about how “science changes people’s lives.” This podcast isn’t explicitly nature-focused, but the fact I’ve been listening for years, and the specific science focus definitely skewed the results here.
The Story Collider’s “The Sea Urchin Massacre” as told by Adam Foote, talks about the difficulties obtaining sea urchins for research while in a landlocked city, in the middle of a polar vortex. Time: 22:12
The Story Collider’s “A Taste of Nature” as told by Deborah Blum, tells a story about a dinner party when she was seven years old, when she asked a question that led to E.O. Wilson investigating a toxic exposure. Time: 14:22
The Story Collider’s “The Mountain Lion Book” as told by Darcy Burke, who talks about how a single book about mountain lions, given to her a child, influenced her career as a science writer. Time: 13.25
Surprisingly Awesome’s “Pigeons,” which investigates the relationship between pigeons and humans (and how much we used to love them). Time: 34:26
The Moth’s “The Call of the Wild,” a story told by Bokara Legendre, who talks about growing up on safaris and how she learned about alternatives to safaris that ended with filming animals instead of hunting them. Time: 16:30
Good Job Brain, a trivia podcast, has an episode called “The Great Outdoors” which examines what you should do when a shark is circling you, how to survive an attack of killer bees, and the life of the deer tick (among other things). Time: 57:35
Stuff You Should Know has an episode about sea jellies, which asks: “Jellyfish: Even Cooler than Octopi?” Time: 54:24
We want to know: what are some of your favorite science/nature/environmental podcasts? Let us know on Facebook!Leave a comment
January 13, 2017
By Liz Clift
What does it mean for a giant to fall?
That seems to be what many people were thinking about last weekend when heavy rainfall resulted in the felling of Pioneer Cabin Tree, one of California’s iconic sequoias. Pioneer Cabin Tree was believed to be more than 1,000 years old—and is the subject of many tourist photos.
Pioneer Cabin Tree, however, is only one of several drive-through trees that were created as a means of encouraging tourism (what!? a tree you can drive through?! Let’s hop in the Model-T and go!) and the use of toll roads and railways. The tunnel was carved from an old fire scar–which speaks to the durability of sequoias. In our lexicon of a disposable culture, these trees are built to last, and to form new growth around old scars.
Last weekend, my social media was flooded with people posting pictures of Pioneer Cabin Tree, and other tunnel trees. The effect was to create a story of how we are pulled to the things that are bigger than us, to the mystery of the natural world, to the way earth will show us its history and ours.
I think it’s easy for us to become complacent—to assume that things that iconic and/or much older than us (or even more than we’re capable of imagining) will always be there. It speaks to the limits of our imaginations. It speaks to the limits of what we can know and predict about the world.
As restoration professionals, we must think about not only what a landscape might look like in six months or a year, but in a decade, in a century, in five centuries and beyond. Of course, we cannot know these things. We can make guesses based on what we know about forest management or hundred-year floods or predicted sea-level rise. We make guesses based on what we know about succession, what we know about the land’s status as protected (or not). We model and forecast. We look for trends in the past to predict future trends.
If we think about Pioneer Cabin Tree—and what was happening 1,200 to 1,000 years ago—our inability to forecast the far future is even more evident. In 817, King Louis the Pious (son of Charlemagne) was still the newly crowned Holy Roman Emperor. By 1017, the classic Pueblo period of the Anasazi culture (cliff dwellings) were (likely) barely established and the world’s first novel (The Tale of Genji by Murasaki Shikibu) had been completed a mere nine years earlier. To the best of our knowledge, at some point in this period, Pioneer Cabin Tree was a sapling.
It was still alive when it fell.
Pioneer Cabin Tree is far from the first of the giants to fall. Other tunnel trees have gone before it. But this tree fell during a period when more of our tallest and biggest trees are dying, as the California drought stretches on (despite recent rains, including the rains that were falling when Pioneer Cabin Tree toppled).
For me, what makes Pioneer Cabin Tree different is the age of social media. We get to document when our beloveds and our icons die—and certainly for many, the tunnel made this tree iconic. We get to mourn and share in collective grief or sadness or disbelief in an unprecedented way. We also get to share our stories and memories—such a critical part of our human culture—and partake in the stories and memories of others.
The most memorable image that came through my social media feed of Pioneer Cabin Tree was a friend I’ve known for nearly a decade, re-posting a picture from 2008. At the time, his daughter was still in elementary school. He was then about the age I am now. The photo itself was unremarkable: the family in the foreground, the tree in the background. What was notable to me was how social media allowed him to document this (and dredge it back up). The photo, perhaps taken by a fellow tourist, captured the most fleeing of moments.
Our histories are short. Our stories sometimes last longer. What stories will you tell?Leave a comment
January 11, 2017
By: Liz Clift
If you regularly read Great Ecology’s blog, it should come as no surprise that I have a soft spot for pollinators (currently with a focus on native bees, which I’m just beginning to learn about). It should also come as no surprise that I’m fond of citizen science, and opportunities for people (including children, educators, and others) to participate in science and field studies.
So, I’ll start with the good (and simultaneously bad) news: Seven species of the Hawaiian yellow-faced bee (Hylaeus sp.) were listed as endangered species on Friday, September 30th, 2016. They are the first bees to make the list, and this could have a ripple effect on other bees and insect pollinators, as protections for these bees are implemented.
This is good, because these bees will now have federal protections. It’s bad, because like with all other species that make the list, it means their numbers are critically low—and we are quite dependent on pollinators (no comment on pollinating robots).
If you’re like me, you’d like to make efforts to support bee pollinators. But, perhaps you don’t have a yard or even a patio to plant flowering plants on. Or perhaps you live in the middle of a city with very few flowering things that can act as “bee highways” to help get bees to your location. Or perhaps you have a bit of a black thumb.
There are still things you can do!
Bumble Bee Watch, “is a collaborative effort to track and conserve North America’s bumble bees.” To participate, you need to have access to a camera (luckily, most of us now carry one around in our pockets all the time), the internet, and some places bumble bees might like to buzz about.
Bumble Bee Watch encourages citizen-scientists to take photos of bumble bees and then upload them onto the Bumble Bee Watch website, where you are asked to try and identify your bumble bee and map where you saw it. An expert later verifies your identification. You have to sign up on the Bumble Bee Watch website to participate—or to browse their gallery—but in exchange, you get to help science by doing something you may already be doing (such as photographing bees or flowers; gardening; or generally being outside with your phone in places where you might see bumble bees).
Your participation helps build a map of bumble bee sightings, and the data can be used to help all of us better understand how bumble bee species shift over time, if their numbers are growing or declining, or if a certain species still exists in a particular area.
Bumble Bee Watch, and the citizen-scientists who participate in this project, helped develop some important records of the rusty patched bumble bee (Bombus affinis). In late September 2016, the US Fish and Wildlife Service (USFWS) announced that it is proposing to list the rusty patched bumble bee as an endangered species under the Endangered Species Act (ESA), due to large declines in 9/10ths of its historic range. This is due, in part, to work done by the Xerces Society. This week, the rusty-patched bumblebee was added to the endangered species list.
The ESA listing may provide major aid to the other 3,600 species of native bees that exist in North America, because of the work that will go into protecting the rusty patched bumble bee from threats of disease, pesticide, and habitat loss. In fact, pesticides and diseases (like Nosema bombi, a fungal parasite) carried by commercial bumble bees are thought to be primary culprits in the decline of the rusty patched bumble bee.
If you want to learn more about the rusty patched bumble bee, you can watch this short video (approximately 20 minutes).
Want other ways to help? The Xerces Society has published guidelines for creating and managing habitat that will attract bumble bees and other pollinators, and Great Ecology is able to help private and public sector clients incorporate pollinator gardens into their projects.
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January 10, 2017
By Liz Clift
Wildlife corridors are designed to help limit the impacts of human infrastructure on animals. These impacts can look like increased fragmentation of habitat areas for animals, the development of dense urban areas, busy freeways or other roads, building dams, and other things. An estimated 1 to 2 million cars hit animals every year—and that number only includes reported instances of collisions, so it’s likely the number is even higher. This indicates that there are strong social (and economic) reasons to implement wildlife corridors: people generally only report hitting large animals or when the collision creates a disabled vehicle.
Wildlife corridors can take many forms, including underpasses, gaps in guard rails, bridges, and connected habitat corridors (i.e. – riparian areas for migratory animals) that are designed specifically to allow species to move (more) safely across roads and other barricades—which can include large swathes of developed areas.
I was reminded of the significant impact wildlife corridors can have on animal welfare recently, while reading about one of the Santa Monica mountain lions (P-39; Puma concolor), a young female lion, who was killed while crossing a highway in the Santa Monica mountains. Her young cubs were orphaned as a result, and according to the National Park Service, are not expected to live.
P-22, the mountain lion which has made Griffith Park (home of the Hollywood sign) his home managed to safely cross two freeways and through a densely populated urban area to reach the park which is only 8 square miles (he could use up to 200 square miles as his territory, if that was an option). But, in this isolated area, he is unlikely to find a mate and he is subject to exposure to rodenticide, as well as other pollutants.
Wildlife corridors not only provide a way for animals to move from one place to another more safely—it can also be a way of creating enough territory that a species of animal can just survive. One example of this is the Terai Arc Landscape, which traverses 14 different protected areas in India and Nepal. The protected areas are comprised of grasslands, forests, and river valleys, and as such offer critical habitats to a number of species including Indian rhinos (Rhinoceros unicornis), Asian elephants (Elephas maximus), and Bengal tigers (Panthera tigris), all of which are considered vulnerable or endangered. Individually, the parks and preserves don’t offer enough acreage to support these species, but connected they provide plenty of habitat range.
Other examples of wildlife corridors include overpasses off Highway 9 in Colorado that allow elk to migrate; a bridge structure in Australia that allows crabs to scuttle up and over a road during their migratory season, turtle underpasses in Florida, and Norway’s bee highway. Design—and purpose—of these corridors matter, and the type of animal(s) and their preferences or needs around habitat must be considered when creating wildlife corridors.
Wildlife corridors are not currently a standard part of restoration projects in a traditional sense—but restoring or enhancing habitats, and strategically planning to preserve or build around specific flyways or migratory pathways can serve many of the same purposes. These things allow for the less habitat fragmentation and less obstructed movement of wildlife. Restoration efforts can also enhance critical habitat areas (i.e. – resting, breeding, or nesting spots) and decrease the influence of human development (i.e. road noise, river sedimentation due to increased runoff).
Restoration professionals, science educators, conservationists, departments of transportation and others can all help clients and the public better understand the benefits of wildlife corridors—not only for wildlife, but for people as well.Leave a comment
January 3, 2017
By Liz Clift
When was the last time you really thought about the roly poly (Armadillium vulgare)? You know the little detritivore that primarily consumes dead plant materials
As a kid, I collected roly polies and kept them in jars. I didn’t know that they were a type of crustacean . I liked that these isopods came in browns and greys and near-black. I liked that they curled up in my hand and I could gently roll them around on my palm. I liked that when I flipped them over on their backs, their little legs wiggled around. I grew up in the south—an environment with lots of moisture and decaying plant matter, their preferred habitat—and so I’d find them under logs and rocks and in piles of pine needles—but also crawling into the swimming pool and walking steadily along the side of the wall under water.
It wasn’t until I was doing restoration work, and installing a native plants garden, on a previous employer’s property, that I ever saw a roly poly that wasn’t an “earth tone.” The one I found was blue. This blue coloration was caused by something caused iridovirus, which is deadly to the roly poly (not to humans). The virus can also cause the isopods to appear purple.
Roly polies are also susceptible to environmental stressors, such as the addition of nitrogen-based fertilizers, which are commonly applied to field crops, and insecticides. The permethrin-based insecticides have proved especially fatal to roly polies, which is unfortunate since permethrin-based insecticides are pretty widespread and roly polies do not appear to have mechanisms for detecting and avoiding them.
As if all of this wasn’t enough of a struggle, roly polies are also impacted by a microbe called Wolbachia. This microbe alters the development of hormone-producing glands, which means that a genetically male roly poly (ZZ chromosomes) who is infected with Wolbachia grows up to be female. Eventually genetically female (ZW chromosomes) roly polies disappear from a population (and all the roly polies appear with ZZ chromosomes).
Scientists have been studying this phenomenon for forty years, and in the 1980s, some scientists showed that some populations that are not infected with Wolbachia still have only ZZ individuals. They had no way of proving their hypothesis: that the microbe had left a piece of its DNA behind and that was influencing the chromosomal make-up, but as of this year, science is close to proving they were right.
The long and the short of it is this: ZZ individuals who are female always have a trace of Wolbachia hanging out in their DNA; those who are male don’t. Ever. Wolbachia turns one of the roly poly’s other chromosomes into a new sex chromosome that behaves like the disappeared W chromosome.
The science is still out on this research around roly poly DNA and how it may or may not be influenced by Wolbachia, at least for now. Some other researchers are waiting for further data to come in, and wonder if perhaps other chromosomes impact sex. All of this research is important—even though, perhaps, most of us wouldn’t think twice about the biological sex of a roly poly or how it feels in say a flooded environment or one laced with permethrins—because it demonstrates the intricacy of natural systems and how small shifts can have a major impact.Leave a comment
December 27, 2016
Let’s talk about something really practical.
It’s winter, and for a lot of us—especially those of us living in drier and colder places—that means not only chapped lips, but also chapped hands.
This can be particularly true if our work takes us outside frequently—as is true if we work with or manage open spaces, parks, or other public or private lands.
Chapped hands might itch, or crack, or bleed. Cracking and bleeding can be painful, and provide more opportunities for the usual nasties to sneak in and cause an infection. At the very least, these things can be hard to keep clean.
It’s because chapped hands are very real (and uncomfortable) that I started making a healing hand cream about a year ago. At the time, it was a direct response to a friend who had perpetually chapped hands (of the cracked, bleeding variety) from parenting two young children and the frequent hand washing associated with that. But, I’ve since gifted it to friends who spend a lot of time outdoors or work in professions where frequent hand washing is a must.
The hand cream I make is based on several different recipes, but the important thing is that it contains a higher level of oil (coconut, because that’s easy to come by) to beeswax, which makes it a softer consistency and enables it to be absorbed more quickly into the skin.
This hand cream doesn’t take long to make and mostly contains ingredients you can find at your local healthy-foods grocer if you don’t already have them at home. I recommend storing it in a small metal or plastic container if you’re out in the field a lot, but if it’s just sitting around your house, you can probably get away with keeping it in a glass jar (though be careful of picking it up and putting it down with your newly hydrated hands!).
With this cream, a little goes a long way. Try out just a little the first time and then use more if you need it.
Healing Hand Cream
.5 oz (by weight) of pure, unscented beeswax (grated or in pellet form)
1 oz almond, grapeseed, or extra-virgin olive oil
1 oz coconut oil
2-3 drops Vitamin E oil
Essential oil, optional* (I like lavender)
Container to store the balm in
Chocolate melter or double-boiler
A deep glass measuring cup and a hand mixer**
Clean and sterilize all your equipment—since we’ll be putting this on our chapped hands, which could have micro-cuts, we’ll want to make sure we decrease any risk of infection.
Combine the wax and oils except the essential oil, if using, in the double-boiler, and allow everything to melt together. Once melted, add a few drops of essential oil, if using. Pour it into a deep glass measuring cup, or another glass or metal container that you can use your hand mixer in.
Whip the mixture, periodically scraping down the sides, until the cream is room temperature and creamy. This could take a while, but resist the urge to do anything extra to cool it down. If any moisture gets into it, you’ll ruin the batch and need to start over.
Store in an air-tight container in a cool, dark place or use an opaque container.
*If you use essential oils, the smell won’t be as strong as it is diluted in these others, so if you want additional scent, you may need to slowly up the amount you use, checking every couple of drops to see if it’s at a level of scent you’d like. Lavender has some anti-bacterial properties. Be cautious about using citrus-based essential oils. These can cause you to burn more quickly in the sun.
**If you don’t have a hand mixer, you can double or triple the recipe (use the extra as gifts!), and use a stand mixer, or you can whip this sucker up by hand—just prepare to be working at it for a while!Leave a comment
December 22, 2016
“This grand show is eternal. It is always sunrise somewhere; the dew is never all dried out at once; a shower is forever falling; vapor ever rising. Eternal sunshine, eternal sunset, eternal dawn and gloaming, on seas and continents and islands, each in its turn as the round earth rolls.” –John Muir
Cloud forests (aka upper montane rainforest or montane laurel forest, among other names) are one of the ecosystems that are disappearing as the planet grows warmer, and with them, many of the plants and animals that have made these unique systems home. A cloud forest is generally located in the tropics or subtropics, and displays a montane and moist evergreen forest characterized by persistent or frequent low-level cloud cover.
Cloud forests are likely remnants of the last ice age. The trees in this area “retreated” to higher elevations as a way to survive the invasion of tropic trees as the planet warmed, and the descendants of those trees are the ones that still exist in Mexico and Central America. These cloud forests host many endemic plant and animal species and are a “living reservoir” because they capture and store so much water. In addition, the water that comes from these forests is cleaner than some other sources of water—vegetation and slow infiltration of the water that falls into streams or rivers does a lot of work to filter the water.
But these forests are disappearing. This is due to a variety of stressors, including human actions like logging and clear-cutting tropical forests to harvest tropical hardwoods and to develop coffee plantations (among other reasons). This is because tropical forests in the lower elevations helped capture and store moisture, which would create microclimates and draw moisture further inland or to higher elevations. As these areas become drier and hotter, through deforestation, that moisture doesn’t always make it to the cloud forests.
At the Instituto Nacional de Ecología y Cambio Climático, researchers are working with research plots to help determine which trees will grow with the changing climate, and why an oak might grow in one location but a walnut or another tree might not. The hope is that by planting a variety of native trees at various elevations, researchers will be able to begin to understand which trees will thrive at which elevations.
This type of facilitated restoration practice is not new—and research on cloud forests shows that these types of restoration efforts can help a cloud forest recover quickly. This is good, since continued ecosystem loss means not only lost ecosystem services that directly benefit people, but also the continued loss of species we may not even know exist yet (earlier this year, scientists made an announcement about three new species of micro-salamanders that were discovered in a cloud forest).
And we know that facilitated restoration does help ecosystems recover—whether it is this specific and critical research in cloud forests, or using developed best practices and plantings for your region.
If we think about this in terms of the eternal, perhaps we have to ask ourselves how we want to contribute to the eternal—to dawn still breaking over cloud forests, to the call of birds among the mist, to the continued existence of amphibians and other species we didn’t know existed. And perhaps we must also think about how our work as restoration ecologists or conservationists (or educators or regulators or any number of other careers) functions to help perpetuate certain eternal systems.
What better time to do this than at the cusp of the new year?
Check out these gorgeous cloud forest photos from Mexico! These ecosystems are also found in South America, Africa, Southeast Asia, and the Caribbean.
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December 12, 2016
It’s no secret that California is entering Year 6 of a drought-period. And though this rainy season has had one of the wettest starts in 30 years, at least in northern California, that doesn’t guarantee the end of the drought. In fact, the Department of Water Resources made an announcement in November that State Water Project customers can expect to receive 20% of their requested deliveries in 2017 (this is an initial estimate and likely to change).
Part of what impacts this is the overall health, or depth, of the snowpack in the Sierras. Snowpack can store millions of acre-feet of water that refills lakes and reservoirs as it melts—and how empty or full lakes and reservoirs appear provide a quick indicator of overall drought conditions.
However, it’s more difficult to account for some of the other impacts of a prolonged period of drought. Since 2011, more than 102 million trees in California have died, more than half of them (62 million) this year. These trees provide important ecosystem services, including supporting healthy watersheds, providing wildlife habitat, and acting as a “carbon sink”—meaning they capture atmospheric carbon. Even giant sequoias (Sequoiadendron giganteum), which are usually fairly resilient during drought periods, are showing evidence of drought through browning crowns and showing up as standing dead (sequoias are more likely to fall over when they die, because they’ve stretched too far from their stabilizing root systems).
Researchers Wendy Baxter and Anthony Ambrose began studying the impacts of drought to sequoias in 2015, with the support of the National Park Service (NPS). They, along with a team of volunteers, climb the sequoias using jumar ascenders, and collect samples at a couple of different points—including from the crown of the tree. These samples help researchers understand the severity of water stress the sequoias are under, the water content in their needles, and the amount of carbon-13 isotope the tree uses during the photosynthetic process (which provides additional insights into drought stress).
This information will ultimately be used in forest management—and could include selective thinning that would eliminate less resilient trees that are competing for water.
And the competition is tough: giant sequoias can take in 800 gallons of water per day. Water is drawn up through the xylem primarily through the release of water vapor through the leaves’ open stomata (transpiration). This creates a vacuum affect. As leaves conduct photosynthesis, water and sugars flow down the phloem*. These sugars are then either stored for later use when photosynthesis slows or used for the tree’s basic maintenance. As drought conditions continue, the tension created by the transpiration process increases and can eventually snap the xylem. This creates an embolism that prevents additional water from flowing up the trunk. If this happens too much, a tree will shed its leaves and eventually die.
Baxter and Ambrose aren’t the only research team working to figure out what’s happening with California’s forests. Another comes in the form of an airborne observatory that maps what’s happening with trees across the state (the technology is advanced enough that the observatory can pick up images about what’s going to become apparent to the human eye).
This should concern us all because forests act as carbon sinks—and if they are dying, that means the carbon will be released back into the atmosphere. Higher levels of atmospheric carbon are linked to global climate change. In addition, forests have a cooling effect on the surrounding area, in part due to the transpiration process, and provide habitat for many different species.
We’ll have to see what this rainy season in California brings—it is a La Niña year, which comes with the possibility of a relatively dry winter, despite the wet beginnings of the season.
*Like that pneumonic? Flow down à phloem!Leave a comment
December 5, 2016
Coconut water. Coconut milk. Coconut cream. Coconut butter. Coconut oil. Fresh coconut meat. Dried, unsweetened coconut. Dried, sweetened coconut. Coconut flour. Coconut sugar. Coconut aminos. Coconut vinegar.
That’s a lot of coconut (and here’s a recipe that uses five different forms of coconut).
And that’s not even including the uses for the leaves, shells, and fibers associated with coconut—and we know from watching Tom Hanks in Cast Away that coconuts are pretty useful.
But the coconut is in danger.
Bacteria that cause a lethal yellowing are wiping out coconut trees in the Caribbean, Cote d’Ivoire, and Papua New Guinea (the latter two, of which, are living seed banks for the coconut). The proposed name for the version in Florida and the Caribbean is Candidatus phytoplasma palmae – and it affects not only coconut palms, but other palms as well, including the date palm. A variety of subgroups of phytoplasmas exist, and scientists are still debating appropriate nomenclature.
Although it’s called lethal yellowing, yellowing of the foliage isn’t the first sign in mature plants. Instead, for those palms that produce fruit, the earliest symptom is a premature drop of most, or all, of the fruit, and in coconuts, one end usually develops a brown to black appearance.
This is not a new problem. The earliest known reporting is 1834 in the Cayman Islands, with similar reports in Nigeria and the Dominican Republic before 1920.
But, I’m getting into the weeds.
The takeaway is this: the coconut is the seed and they don’t store in seedbanks easily. So, we can’t just save seeds until scientists figure this out. Instead, we have to use living seedbanks—which means coconut plantations specifically dedicated to growing coconuts for posterity. Because coconut trees can grow so tall, ensuring genetic purity can be difficult (it’s a risky task to climb a coconut palm and pollinate it, much less to bag female flowers so you can ensure they are only pollinated by the appropriate male flowers).
And of the five international living seedbanks—in Brazil, Indonesia, India, Cote d’Ivoire, and Papua New Guinea—as I mentioned above, the last two are threatened by the bacteria. Additionally, all are in places where land grabs may threaten the plantations.
Unfortunately, there is no simple solution for what we can do about this.
The International Coconut Genetics Resources Network has funded research that has focused on isolating and freezing coconut embryos (fun fact: most of the coconut’s meat and milk is endosperm, which is what allows the embryo to develop!). While scientists have figured out how to successfully freeze embryos, thaw them, and then grow them in a controlled environment until they are large enough to plant in the soil, the success rate is only 5-10%. Unfortunately, additional funding for this type of research is difficult to come by. Most coconut growers are small farmers who only maintain a few acres. They don’t have the money to help invest in coconut research or gene banks. In other industries, big companies usually foot the bill for this type of research—a good practice, if they want to be able to continue to market a resource.
This hasn’t happened yet for coconuts.Leave a comment
November 29, 2016
Recently, I wrote about the tradition of oyster stuffing—and the reality that some people eat oysters at all (not to yuck your yum, as the youth I used to work with would say, but it bears repeating: ew!).
In this blog, which is part of a series on bivalves, I’m going to focus more on the ecology of oysters. We’ll start again in New York. In the last blog, you’ll remember me saying that oyster production in New York peaked between 1880 and 1910, which was part of the “progressive era” in American history—a time categorized by historians as a period of modernization of natural resource management (among other things). However, this wouldn’t help oysters.
As oyster populations decreased, the bivalves were no longer able to filter all the water in New York Harbor (an adult oyster can filter about 40-50 gallons of water a day), and toxicity became a concern. By 1927, the last oyster bed in New York was closed due to health concerns, and there weren’t any improvements in the health of oyster beds until the 1972 Clean Water Act (CWA). Nearly 45 years later, however, the oysters of New York Harbor are still too polluted to eat and dredging can further complicate oyster health by stirring up centuries worth of pollution that has settled onto the harbor floor.
Overharvesting and high levels of pollutants aren’t the only threat to oysters. Warmer ocean temperatures are leading to ocean acidification—higher levels of carbon dioxide (CO2) are present in the water—which can prevent the shells of young oysters from solidifying. In the previous blog, I talked about pathogens which also impact oysters—including Vibrio, MSX, and dermo—so I won’t rehash that here, but warmer waters can mean that these diseases are spreading beyond their historical presence. In addition, oysters still have to deal with their natural predators, which in addition to people include:
The plight of oyster is so bad that portions of the East Coast only have 1% of their historic natural oyster population—despite efforts to repopulate oysters. Fortunately, New York and many other areas are taking oyster repopulation serious. This is good because oyster reef abundance has decreased approximately 85% globally in the past century. Oysters help filter pollutants from water (though they can do nothing about heavy metals and PCBs, except absorb them into their bodies, which can render them dangerous to humans). Oyster reefs can also help stabilize sediments and slow wave-induced erosion, which can make a big difference in areas where coastal loss is a problem.
Although restoration efforts are underway up and down the East Coast and in other parts of the world, it will likely be years before oyster populations are restored enough to provide the same level of various ecosystem services that they once provided—and that’s assuming oyster harvesting is well-managed, and that diseases that can affect oysters don’t boom alongside these restoration efforts.
These restoration efforts, like all restoration efforts, should also include monitoring. This can help evaluate the state of the habitat, detect recruitment and survival rates, understand how the ecosystem is functioning, and recognize the interaction of species in and near the reefs.
*This video shows mussels, not oysters, but you get the idea.Leave a comment