Earthbytes

Streamflow Alteration Impacts Fish Diversity in Tennessee River Basin

A new USGS study quantifies how the diversity of fish changes when stream flow is altered in the Tennessee River basin:

The USGS study highlights the importance of the timing, magnitude, and variability of low streamflows and the frequency and magnitude of high streamflows as key characteristics critical to assessing how fish communities change in response to streamflow alteration. This study was completed using fish community data collected by the Tennessee Valley Authority, and predictions of streamflow characteristics at more than 600 locations.

The Tennessee River basin is one of the richest areas of aquatic diversity in the country, if not the world.  However, expanding urban development, more than 600 privately held small dams on medium to small streams, and withdrawal of more than 700 million gallons of water each day threaten this diversity.  Understanding the effect of streamflow alteration on aquatic ecology is increasingly important as change in land use and human population are projected.

Read more in the USGS press release and at USGS Tennessee Project: Environmental Flow Research.

Insectivorous fishes, such as Percinidae darters, Cyprinidae minnows, and Noturus madtoms, are among the most jeopardized fish in the Tennessee River Valley. Insectivorous fish represent a middle ground in the trophic structure of a stream, feeding on invertebrates while being prey for predator species. For their eggs to hatch insectivorous fish must lay them in gravel beds that are relatively clear of sediment. Insectivorous fish are sight-feeding and need clear water for feeding.

See more:

Streamflow influences fish health and abundance in Tennessee

Earth Day 2013

USGS: Tiny Grazers Play Key Role in Marine Ecosystem Health

Tiny sea creatures no bigger than a thumbtack are being credited for playing a key role in helping provide healthy habitats for many kinds of seafood...

Gammarus mucronatus, an amphipod grazer that can promote healthy eelgrass beds. Copyrighted photo courtesy of Matthew Whalen/UC Davis. (High resolution image)

According to a recently published study by the Virginia Institute of Marine Science and U.S. Geological Survey, tiny crustaceans like Gammarus mucronatus (see photo above) play a critical role to protect seagrasses from overgrowth by algae. By eating algae on seagrass, these small animals keep ocean environments healthy for native and economically important species.

“Inconspicuous creatures often play big roles in supporting productive ecosystems,” said the study'd lead author, Matt Whalen. “Think of how vital honeybees are for pollinating tree crops or what our soils would look like if we did not have earthworms. In seagrass systems, tiny grazers promote healthy seagrasses by ensuring algae is quickly consumed rather than overgrowing the seagrass. And by providing additional refuge from predators, fleshy seaweeds that drift in and out of seagrass beds can maintain larger grazer populations and enhance their positive impact on seagrass.”  

 USGS scientist Jim Grace, a study coauthor, says that seagrass habitats are also beneficial to people.

“Not only do these areas serve as nurseries for commercially important fish and shellfish, such as blue crabs, red drum, and some Pacific rockfish, but they also help clean our water and buffer our coastal communities by providing shoreline protection from storms,” Grace said. “These tiny animals, by going about their daily business of grazing, are integral to keeping healthy seagrass beds healthy.”

Comparison of algae fouling on eelgrass with and without grazers. Copyrighted photo courtesy of Matthew Whalen/UC Davis. Copyrighted photo courtesy of Matthew Whalen/UC Davis. (High resolution image)

Without these algae grazers, say the authors, algae could accumulate in a thick enough layer to block sunlight and prevent the seagrasses from photosynthesizing, which would kill them.  The decline of seagrass in some areas is partly the result of excess nutrients in water that stimulates excessive algal growth on seagrasses. 

J. Emmett Duffy of the Virginia Institute of Marine Science, another coauathor of the study, says that coastal managers have been concerned for years about excess fertilizer and sediment loads that hurt seagrasses. Duffy sees study results as convincing field evidence that tiny animals that graze on algae can be just as important as good water quality to prevent algal blooms and keep seagrass beds healthy.

The study, “Temporal shifts in top-down versus bottom-up control of epiphytic algae in a seagrass ecosystem,” was published in the recent issue of Ecology, a journal by the Ecological Society of America.

Read more about seagrass:

Related articles

Kaipara is 'last harbour standing'

Tohoku coast faces man-made perils in wake of tsunami

Need to Read: Wales' secret underwater habitats captured by new video project

PLoS ONE: Elevated Mortality among Birds in Chernobyl as Judged from Skewed Age and Sex Ratios

ABSTRACT

Background

Radiation has negative effects on survival of animals including humans, although the generality of this claim is poorly documented under low-dose field conditions. Because females may suffer disproportionately from the effects of radiation on survival due to differences in sex roles during reproduction, radiation-induced mortality may result in male-skewed adult sex ratios.

Methodology/Principal Finding

We estimated the effects of low-dose radiation on adult survival rates in birds by determining age ratios of adults captured in mist nets during the breeding season in relation to background radiation levels around Chernobyl and in nearby uncontaminated control areas. Age ratios were skewed towards yearlings, especially in the most contaminated areas, implying that adult survival rates were reduced in contaminated areas, and that populations in such areas could only be maintained through immigration from nearby uncontaminated areas. Differential mortality in females resulted in a strongly male-skewed sex ratio in the most contaminated areas. In addition, males sang disproportionately commonly in the most contaminated areas where the sex ratio was male skewed presumably because males had difficulty finding and acquiring mates when females were rare. The results were not caused by permanent emigration by females from the most contaminated areas because none of the recaptured birds had changed breeding site, and the proportion of individuals with morphological abnormalities did not differ significantly between the sexes for areas with normal and higher levels of contamination.

Conclusions/Significance

These findings are consistent with the hypothesis that the adult survival rate of female birds is particularly susceptible to the effects of low-dose radiation, resulting in male skewed sex ratios at high levels of radiation. Such skewed age ratios towards yearlings in contaminated areas are consistent with the hypothesis that an area exceeding 30,000 km² in Chernobyl’s surroundings constitutes an ecological trap that causes dramatic excess mortality.

via www.plosone.org

New Deep-Sea Hydrothermal Vent Communities Found in the Southern Ocean - PLoS Biology

Interesting (open access) study of organisms found in hydrothermal vent areas of the Southern Ocean...important discovery relative to biodiversity of species in this underexplored region of Earth's oceans.

Authors Summary:

Deep-sea hydrothermal vents are mainly associated with seafloor spreading at mid-ocean ridges and in basins near volcanic island arcs. They host animals found nowhere else that derive their energy not from the sun but from bacterial oxidation of chemicals in the vent fluids, particularly hydrogen sulphide. Hydrothermal vents and their communities of organisms have become important models for understanding the origins and limits of life as well as evolution of island-like communities in the deep ocean. We describe the fauna associated with high-temperature hydrothermal vents on the East Scotia Ridge, Southern Ocean, to our knowledge the first to be discovered in Antarctic waters. These communities are dominated by a new species of yeti crab, stalked barnacles, limpets and snails, sea anemones, and a predatory seven-armed starfish. Animals commonly found in hydrothermal vents of the Pacific, Atlantic, and Indian Oceans, including giant Riftia tubeworms, annelid worms, vent mussels, vent crabs, and vent shrimps, were not present at the Southern Ocean vents. These discoveries suggest that the environmental conditions of the Southern Ocean may act as a barrier to some vent animals and that the East Scotia Ridge communities form a new biogeographic province with a unique species composition and structure.

via www.plosbiology.org

EcoWatch launches nationwide news service website today

Robert F. Kennedy Jr. Joins EcoWatch to Announce Launch of Nationwide News Service Website

Live Webcast at www.ecowatch.org begins at 3 p.m. EST

WHAT: Launch of Nationwide News Service Website with Robert F. Kennedy, Jr. as Keynote

WHY: Celebrate EcoWatch and Waterkeeper Alliance’s Nationwide News Service

WHEN:   Thursday, Oct. 27 at 2:30 p.m. EST

WHERE: Rivergate Park, 1785 Merwin Ave., Cleveland, Ohio 44113

Cleveland, OH—EcoWatch, in partnership with Waterkeeper Alliance, is hosting a public event today along the Cuyahoga River to celebrate the launch of their nationwide news service website with Robert F. Kennedy, Jr., founder and president of Waterkeeper Alliance, as keynote speaker.  The website—www.ecowatch.org—went live this morning and will work to unite the voice of the grassroots environmental movement and mobilize millions of Americans to engage in democracy to protect human health and the environment.  

The website expands EcoWatch’s coverage nationwide and becomes the first media source to focus exclusively on environmental news culled from more than 700 environmental organizations across the country.  The site showcases original content in its Insights column from leading national voices in the environmental movement, including EcoWatch’s advisory board members. 

The news service provides timely access to relevant information that seeks to motivate individuals to become engaged in their community, adopt sustainable practices and support strong environmental policy.  The site focuses on five critical issue areas—water, air, food, energy and biodiversity—and covers topics including, renewable energy, water and air quality, sustainable agriculture, fossil fuel depletion, solution-based sustainability projects, species protection, global warming, climate change and pending legislation.

“The current assault on America’s environmental laws, like the Clean Water Act, creates a pressing need to educate and engage people to protect our infrastructure, the air we breathe, the water we drink, to provide our children with the same opportunities for dignity and enrichment as our parents gave us,” said Kennedy. “This website encourages people to be part of the solution and engage in democracy.”

EcoWatch, publisher of EcoWatch Journal with a distribution of more than 80,000 copies across Ohio, will launch the nationwide news service out of Cleveland’s Tremont neighborhood and become part of the growing online news media market.

“Northeast Ohio is a national leader in sustainability and EcoWatch is proud to call Cleveland its home,” said Stefanie Penn Spear, founder and executive director of EcoWatch. “This news service website follows the model we developed in Ohio over the last five years and expands on my more than 20 years of publishing environmental news.”

The public event will feature brief remarks from Cleveland Mayor Frank Jackson; Cleveland City Councilman Joe Cimperman; the George Gund Foundation’s Senior Program Officer for the Environment, John Mitterholzer; the Cleveland Foundation’s Program Officer, Nelson Beckford; and Kennedy, a member of EcoWatch’s advisory board, who will serve as keynote speaker. 

Other advisory board members are Wendy Abrams, an eco-advocate and philanthropist; Ed Begley, Jr., an actor and environmentalist; Lester Brown, a  prize-winning author and critical thinker; Laurie David, a bestselling author and activist; Paul Hawken, an environmentalist, entrepreneur and author; Randy Hayes, founder of Rainforest Action Network; Phil Radford, executive director of Greenpeace, and Harvey Wasserman, an anti-nuclear activist.

In addition to commemorating the launch of the national website, EcoWatch and Waterkeeper Alliance will acknowledge the significance of the celebration’s location, near the historic site where the then oily Cuyahoga River caught on fire in June 1969.  This event played a major role in the growth of the modern-day environmental movement and passage of the Clean Water Act. The event will also highlight the need for water advocacy and stewardship, public access to our waterways, human-powered recreation on the water and collaboration on solution-based projects like Rivergate Park. Immediately following the event, participants are encouraged to enjoy Rivergate Park, home to the Cleveland Rowing Foundation, by touring the grounds and watching rowing, kayaking and paddleboarding on the river.

Kennedy will also keynote a fundraising event at Windows on the River at 2000 Sycamore St. at 6 p.m. that evening. The event includes a VIP reception, dinner and keynote speech.  Tickets can be purchased at www.ecowatchohio.org.

To view the website, visit http://www.ecowatch.org/.

-------------

EcoWatch is a Cleveland-based nonprofit dedicated to uniting the voice of the grassroots environmental movement and mobilizing millions of Americans to engage in democracy to protect human health and the environment. EcoWatch, founded in 2006, publishes the bimonthly newspaper EcoWatch Journal, distributed for free throughout Ohio printing 80,000 copies per issue. For more information, visit www.ecowatchohio.org

Waterkeeper Alliance is a global environmental organization uniting more than 190 Waterkeeper organizations around

the world and focusing citizen advocacy on the issues that affect our waterways, from pollution to climate change.

Waterkeepers patrol more than 1.5 million square miles of rivers, streams and coastlines in the Americas, Europe,

Australia, Asia and Africa.  For more information, visit www.waterkeeper.org.

This weekend on LinkTV: Seed Warriors

This weekend, LinkTV's ViewChange series will air the documentary Seed Warriors:

In the remote Norwegian town of Longyearbyen, just 1000 kilometres from the North Pole, politicians from around the world came to celebrate the opening of the world’s first global seed bank. After years of difficult negotiations and searching for the right spot, this was deemed to be the safest place on earth. Eventually, 4.5 million seed samples will be stored in this "Doomsday Vault" and ensure the continued existence of biodiversity.

via www.linktv.org

 

The page for the Svalbad Global Seed Vault at Wikipedia has more info and some interesting links.

The first of several showings will air at 7pm eastern tomorrow, Friday, July 22nd on DirecTV Channel 375 and DISH Network Channel 9410.

Cumberland Plateau is one of SELC's top 10 endangered places for 2011

The Southern Environmental Law Center has released its list of the Top 10 Endangered Places for 2011. Included is the Cumberland Plateau in Tennessee, known for its world class biodiversity and number of rare species and at risk for mountaintop removal mining. Also listed is the George Washington National Forest in Virginia, at risk for potential gas well drilling with hydrofracking methods that threaten water supplies.

 

 

What's up with disappearing bumble bees?

According to a study recently published in the Proceedings of the National Academy of Sciences by University of Illinois entomologist Sydney Cameron, bumble bee populations are declining across North America, and individuals in declining populations have higher pathogen prevalence and reduced genetic diversity. (This is a separate issue from the concerns about honeybees and colony collapse disorder.)

While Cameron and her team see these factors as realistic predictors of alarming patterns of decline in North America, a cause and effect relationship remains uncertain:

In an article about her study in the January 6th issue of the News-Gazette, Cameron noted that 'people should be aware of the decline as a loss to nature and to the agricultural industry. Why these significant changes in this country's bumblebee population have occurred is open to speculation. Some factors that Cameron note are climate change (which appears to account for the declines in some bumble bee species in Europe); habitat loss; and the above-mentioned parasite, nosema bombi. 

via www.care2.com

If you're interested in contributing to ongoing observations of bumble bees, check out the National Phenology Network. The NPN brings citizen scientists, government agencies, non-profit groups, educators and students together to monitor the impacts of climate change on plants and animals in the United States.

A couple of bumble bees on an Echinacea flower in my Holler observation plot.

I signed up to be an observer last year and chose bumble bees as one of the animal species I monitor. I picked a small area here in the holler that I walk through almost everyday when I go out with my dogs and cats. I monitor two American beech trees, a redbud, and forsythia as well as jewelweed and dog-tooth violet plants. In addition to bumble bees, I watch for American goldfinches, eastern chipmunks, and whitetail deer.

After selecting the species I wanted to monitor, I used observer training material offered at the website to become familiar with the phenophases -- recurring plant and animal life cycle stages such as leafing and flowering of the plants and trees, feeding behavior of the bees and goldfinches -- so I knew what to look for and how to record it.

"American beech 1" on my NPN observation list is an older tree very close to my house. This was how it looked on October 21, 2010. I occasionally take photos of the species I observe.

Because many of these events are sensitive to variation and changes in climate, notes recorded by citizen observers can help scientists identify and understand environmental trends relative to shifts in climate.

I entered observations into a user-friendly online form linked to my observation plot and species.

This is a photo of "Jewelweed 2" take on October 16th when it was producing seeds:

In some ways, I think because I was closely observing all these plants and creatures on a regular basis, I learned new things about them. I had not really seen the jewelweed seeds before. I was more captivated by the awesome flowers they make and never really stopped by so much after the flowers went away. I was very surprised the first time I put my finger under one of the seeds to get a closer look -- it jumped about a foot or so away from the plant on which it had grown.

It was really fun to participate in the NPN program. With many plant and animal species already responding to climate change, it's very satisfying to be part of a network of so many different people collecting information and paying attention to how things are going.

Professor Cameron noted in the article excerpted above that it would be helpful if people can plant native species that larger species of bees need for habitat.

As we head into 2011, the question of why diversity matters is pretty much in our face

This ambush bug (probably Phymata sp.) represents the awesome diversity of living beings here in Frog Pond Holler. Photo by Cathie Bird

 

I'm always curious about that "one more thing" I feel compelled to do before I go do something else. Last night, that "last thing" I had to do before celebrationg the death of 2010/emergence of 2011 was to read an editorial on global threats to biodiversity in The Guadian:

Biodiversity is all we have. Living things provide humankind's food, fabric, fibre and pharmaceuticals; they fertilise and pollinate crops, generate oxygen and recycle water. The wealth of nations is built upon biodiversity: even the oil, coal, peat, chalk and flints dug from the ground were once living tissue. So the case for the conservation of life's variety ought to be obvious. But biodiversity is a problem in four parts. We do not know, cannot identify, and cannot even begin to count most of the creatures upon whom we depend; nor do we know how these unidentified species interact with and depend upon each other; yet we are extinguishing this richness at a rate perhaps unparalleled in the 3.5bn year history of life on Earth; and we have as yet no masterplan with which to address any of these challenges.

I think I've finally figured out that I'm not a specialist at heart. I like to look for the ways in which many different things are connected, how they operate together in larger systems. Perhaps that's why I felt immediate resonance with the editor(s)' notion of biodiversity as "a problem in four parts" -- this view implies an appreciation of ecological systems, their complexity, and why that matters.

For a long time in my work as an activist, I experienced my interests in liberation for people and liberation for nature as kind of a double lineage of inspiration, parallel tracks for exploration and action. I think that, in my heart, they had always been fundamentally braided as a monorail system inducing (sometimes pushing) me along my life's path.

But in so many ways these interests seemed to come alive in my view of the world -- in the institutions of culture, politics, education, religion, health, law, business -- as being separate. This has been a huge source of frustration for me as a citizen-activist (especially aggravated in the past decade) because arguments based on systemic realities, such as the Guardian editors identify in their discussion of biodiversity, are simply not heard. There is no way for the institutionally-compromised brain to comprehend it.

I've been sitting here for a few minutes trying to think of some collective activity, some arena of life that all of us engage in every day where diversity doesn't matter for the well-being and stability of people and nature. I haven't found it yet.

Given that diversity enhances strength and persistence of life itself, I find it interesting that so much emotional fire has been ignited in opposition to it.

Immigration law battles in several states, intolerance directed at Muslims, gays and lesbians and Latinos, efforts to disempower the Environmental Protection Agency (an agency with a huge role in protecting biodiversity), increased monitoring of American citizens who engage in protected dissent, persistent leftovers from the American Civil War that perpetuate racial and political division -- these are just a few of the hot issues bound up with how much we value diversity.

It's hard to follow national discussions and reportage without becoming acutely aware of the tremendous amount of fear that permeates them. The energetic impact of fear is to limit, constrict, foreclose, exclude. I'm wondering if fear will be the greatest obstacle to achieving and maintaining diversity?

The Guardian editorial hints at these dynamics of fear as they may be playing out in global negotiations on biodiversity:

There is a global convention on biological diversity with 193 signatories, which declares that living species are not the common heritage of all mankind; instead states have sovereign rights over their own biological resources, and therefore implicitly a direct interest in conserving them. Since the richest concentrations of biodiversity are held by the poorest nations, scientists from Europe and the US must negotiate formidable bureaucratic and social obstacles before they can begin research, train local naturalists and start to advise on conservation techniques. Such intricacies forced the last-minute cancellation of a London Natural History Museum initiative in Paraguay in November.

Ultimately, I think it is through our willingness as a group to protect and nurture diversity of people and nature that we express our desire for life or for death, not just for ourselves but for many generations of diverse life that could follow.

Orange day lily near my house in Frog Pond Holler. Photo by Cathie Bird.

Choosing to connect with the Guardian editorial on biodiversity was auspicious. It generated much thought about where to focus my energy in 2011. I see myself exploring all of this -- and writing more about it -- in the coming year.

I sense, as do many others, that we are in an evolutionary moment of profound possibility to choose a lively way forward for Earth and humanity. That path is marked by an energetic matrix of peace, love, co-operation and co-ordinated, harmonious action. All four represent activity that tends toward openness and inclusion, and thus are consistent with protection and cultivation of diversity.

It should be interesting to see how this all turns out...for the Earth...for all of us. Until then, I can certainly stand with the editors at the Guardian who hope for "some serious political investment" over the long haul.