SPECIES INVASIONS: Water Hyacinth and Zebra Mussels

By Bianca T. Esposito, NWNL Research Intern
(Edited by Alison M.  Jones, NWNL Director)

Bianca T. Esposito is a Syracuse University senior studying Biology and Economics. Her summer research for NWNL was on biodiversity and water resources. Her past NWNL blogs are:  Wild v Hatchery Salmon; Buffalo & Bison; Papyrus & Phragmites; & Deer & Elephants.

INTRODUCTION

Invasive species are those that threaten to overtake other species.  Whether flora or fauna, native or introduced, invasive species pose aggressive threats to the quality of lakes and ponds. “Introduced species” aren’t necessarily invasive; and “native species” can become invasive. Introduced species that are aggressive to the point of creating potential problems are termed “non-native invasives.” This blog discusses the impacts of two non-native invasive populations: water hyacinth (flora); and zebra mussels (fauna).  

TO WATER HYACINTH

Jones_110805_CAN_0498.jpgWater Hyacinth at the Montreal Botanical Garden, Canada. 

Water hyacinth (Eichhornia crassipes) is a perennial, free-floating aquatic weed, native to South America’s Amazon River, but carried overseas for ornamental use. Today the water hyacinth is considered to be the “world’s worst aquatic weed.” This aggressive, invasive species spreads rapidly over entire surfaces of lakes and ponds and can double its coverage in just two weeks. Yet its ability to withstand drastic fluctuations in flow rates, acidity and low nutrient levels makes it a viable and popular water-garden plant.  

Since imported to North America in 1884, it has invaded the Columbia and Mississippi River Basins, two NWNL case-study watersheds. Also introduced into East Africa, it is present in three NWNL basins:  those of the Omo, Nile and Mara Rivers. Recorded in Egypt as early as the 1890’s, water hyacinth became a “plague” in the late 1900’s. River control schemes, such as dams, barrages and irrigation canals have encouraged its growth and spread. Furthermore, climate change, a combination of higher temperatures and CO₂ fertilization, is significantly increasing water hyacinth proliferation.

IMPACTS TO NATIVE RIVERINE SPECIES

On the positive side, water hyacinth cleans contaminated waters by absorbing large amounts of heavy metals into its tissue. However, once established, its degradation of waterways crowds out an ecosystem’s native species. Ergo, it becomes a “pest species.”

Jones_091002_TZ_1385Water Hyacinth with Papyrus in Masurua Swamp, Tanzania

On Mississippi River waterways, water hyacinth becomes a mesh of dense mats ─ some spanning hundreds of acres of water. These mats cluster and cause a chain reaction that block sunlight from reaching native submerged plants, deplete oxygen in the water and kill aquatic wildlife, including fish. Ultimately, these mats prevent the growth and abundance of phytoplankton and other rooted benthic, aquatic plants that rely on sunlight and release O2. This negatively impacts fisheries, since phytoplankton is the basis of many aquatic food webs.

Kenyan fishermen on Lake Victoria, source of the White Nile Basin, have seen a 45% decrease in fish-catch rates after water hyacinth mats blocked access to fishing grounds, and thus delay delivery to markets. These consequences have increased costs of fishing efforts and materials. This hurts all who rely on fishing, and decreases the quality of fish in local markets.

In sum, the presence of water hyacinth within water bodies means: No Sunlight – No Photosynthesis – No Oxygen – No Fish. Ultimately, through this chain reaction, water hyacinth destroys the native ecosystems it invades.

EXTENDED WATERSHED DAMAGE BY WATER HYACINTH

Jones_091003_TZ_2892.jpgWater Hyacinth with Papyrus in Masurua Swamp, Tanzania

─ Wind, water currents and boat traffic can break off pieces of water hyacinth mats that then  can drift or blow away into new territories.

─ In sub-freezing Mississippi River Basin winters, water hyacinth mats decompose and literally tons of dead plant matter sink at once to the bottom, creating shallower rivers after several years of this build-up.

─ Water hyacinth disrupts critical values and services by blocking boater access; impeding commercial and recreational boat navigation; reducing water flow; and interfering with hydroelectric power generation.

─ Water hyacinth also affects drainage and irrigation canals by clogging intake pumps and  reducing water flow. This causes floods and damage to canal banks. In recreational waters, water hyacinth invasion  negatively impacts anglers, water-skiers and swimmers.

WATER HYACINTH SOLUTIONS

Water hyacinth management costs are close to US$100 million/year in both the US and Africa. Thus, it is clear that prevention is the most effective and cheapest control.

Another approach is to control expansion. This is usually, but controversially, done with low-cost chemical herbicides labeled “For aquatic use,” such as Glyphosate 5,4. However,  application of this herbicide creates decomposition of dead plant material, thus fostering oxygen depletion which kills fish and other aquatic species.  

Other methods of control include mechanically raking and harvesting the plant ─ as well as hand removal, biocontrol insects (such as the Neochetina beetle) and summer drawdowns. When harvesting and removing the plant, it is crucial to not discard it into a natural water way, but rather contain it in protected compost.

INTRODUCTION TO ZEBRA MUSSELS

Zebra_mussels_line_shore_on_Green_Bay_at_Red_River_County_Park_in_Kewaunee_County_Wisconsin.jpgZebra mussels line Green Bay, Red River County Park, WI (Creative Commons)

Zebra mussels (Dreissena polymorpha), native to lakes in southeast Russia, are another non-native invasive species. In the 19th century, zebra mussels accidentally expanded into western Europe, the UK and N. America through trade. They entered N. America in the 1980’s when a trading boat came into the Great Lakes unaware of zebra mussels in its ballast water. Fortunately, invasive zebra mussels have yet to spread to Africa; but it could happen in the near future through trade.

Zebra mussels are the only freshwater bivalves able to attach to hard substrates in high densities. They reside in larger estuaries, inland rivers and lakes, adapting to hard- and soft-bottom habitats with surfaces suitable for attachment. Their entry into new ecosystems occurs through accidental transportation when attached to the bottom of boats. Once attached to a surface, zebra mussels are nearly impossible to remove. However, juvenile zebra mussels, with their ability to move freely in water, pose an additional threat to uncontaminated waters.

In some areas of the Mississippi River, there are as many as 20,000 zebra mussels per square yard. Since 1986, they have invaded 20 states east of the Mississippi River. There is no detection yet of zebra mussels in the NWNL case-study Raritan and Columbia River Basins. According to the State of NJ, “Zebra mussels have not yet been detected in New Jersey waters, but it is probable that invasion will occur in the near future.”  

The Columbia River Basin, as of Aug 6, 2018, is the only major western US watershed not yet invaded by zebra and quagga mussels. Montana’s Flathead Lake, which drains into the Clark and Pend Oreille River tributaries to the Columbia River, is the last barrier against zebra mussels slipping into the the Columbia River system. One means of protection at the lake, and throughout the Columbia watershed, is extensive warning via signage and implementation of inspection stations, such as one on US Highway 93, that pressure-washes contaminated boats if they are found with mussels.

ZEBRA MUSSELS: NATIVE SPECIES IMPACTS & LOSSES

Zebra_mussels_dreissena_polymorpha_on_native_mussel.jpgZebra Mussels growing up a native mussel (Creative Commons)

Since zebra mussels have no natural predators in new ecosystems, they easily and dramatically reduce native species in US and Canadian fishing communities, by consuming and decreasing the amounts of  food traditionally available for native species, such as algae. Zebra mussels also attach themselves to native species, such as crayfish, turtle shells and other mussels.  In limiting the ability of native species to move, feed, breath and breed, they prevent reproduction and threaten their survival, as happened with the native “Higgins eye pearlymussel.”  

EXTENDED WATERSHED DAMAGE BY ZEBRA MUSSELS

Jones_121030_TX_8719.jpgSign warning for invasive Zebra Mussels at Eisenhower State Park, Texas 

In aggregating on hard surfaces, zebra mussels cause economic impacts on municipal, industrial and private water systems. Since they grow in dense colonies, they can clog intake pipes and change the ecology of their new ecosystems. Zebra mussels also damage ecosystem services; change and alter habitat; decrease oxygen concentration when they respirate; modify natural benthic communities and modify nutrient regime. They  negatively impact human health, aquaculture/fisheries, tourism and disrupt transportation. Even outside of the water, this invasive species destroys beaches with its extremely foul smell upon decaying.

Economic costs to manage zebra mussels impacts the Midwest and eastern US annually at an estimated $1 billion dollars. The Great Lakes region alone spends an estimated $500 million/year scrubbing zebra mussels from docks, pipes and intake pumps. While zebra mussels have not yet spread to NJ waterways, management costs hypothetically would run approximately $336 million/ year. If zebra mussels reach the Columbia River Basin their damage could cost hydroelectric facilities alone anywhere from $250 million to $300 million/ year.

ZEBRA MUSSEL SOLUTIONS

Jones_150816_AZ_5638.jpgSign warning boaters of invasive Zebra Mussels in Goose Lake, Arizona

Currently, zebra mussels are routinely removed from raw water systems where they create a bio-fouling nuisance, and are then discarded in landfills. Mechanical removal of attached zebra mussels is done using high-pressure water cleaning and micro-encapsulated BioBullets. Rigorous boating equipment maintenance by all boat owners is critical in stopping the spread of zebra mussels. Signs in most harbors and ports now warn that boats be cleaned with warm soapy water when entering from another body of water. Additionally, boaters are told not to dump water from one body of water into another body of water, since juvenile mussels move freely. Two critical solutions are 1) every boat owner assuming responsibility and 2) signage that spreads awareness of this invasive species.

CONCLUSION:

Clearly invasive species pose major problems to the new habitats they invade, whether flora, such as hyacinth, or fauna, such as zebra mussels.  In N. America and Africa, water hyacinth has hindered the growth of native aquatic flora and phytoplankton, depleting the aquatic food chain. Adult zebra mussels degrade watersheds by clogging irrigation pipes, and crowding out of native species. Additionally, unattached juvenile mussels easily spread this species to uncontaminated waters. Although invasive species can have some beneficial traits to the watersheds they dominate, degradation by water hyacinth and zebra mussels outweighs their benefits. It is imperative to spread awareness on how to prevent the spread of these and other non-native invasive species in order to protect the health of all impacted watersheds.

All photos © Alison M. Jones unless otherwise noted.


Bibliography:

“African Plant may Help Fight Zebra Mussel Scourge.” Wire Reports, accessed on July 24, 2018, via link
Batanouny, K. H. “The Water Hyacinth in the Nile System, Egypt.” Aquatic Botany, accessed on July 23, 2018, via link
Benson, Amy J. “The Exotic Zebra Mussel.” U.S. Fish & Wildlife Service: Endangered Species, accessed on July 24, 2018, via link.
“Case Study: Water Hyacinth.” U.S. Department of State Archive, accessed on July 25, 2018, via link
Diop, S. “Climate Change Vulnerability and Impacts in River Basins and Aquifers Basins in Africa: Analysis of Key Response Strategies.” Accessed on July 24, 2018, via link.
“Dreissena polymorpha (zebra mussel).” CABI, accessed on July 23, 2018, via link.
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Hanson, Erik and Sytsma, Mark.  “Oregon Aquatic Nuisance Species Management Plan.” Center for Lakes and Reservoirs at Portland State University, accessed on July 24, 2018, via link.
“How to Control Water Hyacinth.” AquaPlant – Texas A & M AgriLife Extension, accessed on Sept 25, 2018 by AMJ, via link.
“Idaho Aquatic Nuisance Species Plan.” The Idaho Invasive Species Council Technical Committee, accessed on July 24, 2018, via link.
Jacewicz, Natalie. “Why A Really Big Fish Isn’t Always Good For Business.” National Public Radio, accessed on July 25, 2018, via link
Leposo, Lilian. “Flower Power Threatens Kenya’s Lake Victoria.” CNN, accessed on July 23, 2018, via link.
Madsen, John D and Robles, Wilfredo. “Water Hyacinth.” Mississippi State University, Geosystems Research Institute, accessed on July 23, 2018, via link.
McLaughlan, Claire. “Making the Best of a Pest: The Potential for Using invasive Zebra Mussel Biomass as a Supplement to Commercial Chicken Feed.” Environmental Management, accessed on July 24, 2018, via link.
Neal, Wes. “Beautiful Water Hyacinth yields long-term damage.” Mississippi State University Extension Service, accessed on July 23, 2018, via link.
Ouellet, Nicky.  “Flathead Lake Healthy, Biological Station Director Says” Montana Public Radio, Aug 6, 2018. Accessed Sept 25, 2018 by amj, via link.
Reilly, Patrick. “At Columbia River’s doorstep, an uneasy lookout for invasive mussels.” The Oregonian/OregonLive, accessed on July 24, 2018, via link
Scott, Tristan.  “Biological Station: No Invasive Mussels Detected in Flathead Lake.”  Flathead Beacon, Feb 17, 2017. Accessed Sept 25, 2018 by amj via link.
Waltham, N. J. “Aerial Herbicide Spray to Control Invasive Water Hyacinth (Eichhornia crassipes): Water Quality Concerns Fronting Fish Occupying a Tropical Floodplain Wetland.”Sage Journals, accessed on July 25, 2018, via link
“Water Hyacinth.” AquaPlant – Texas A & M AgriLife Extension, accessed on July 23, 2018, via link.
“Water Hyacinth.” Southeast Exotic Pest Plant Council, accessed on July 23, 2018, via link.
“Water Hyacinth.” US Department of Agriculture, accessed on July 23, 2018, via link.
“Water Hyacinth Control.” Lake Restoration Incorporated, accessed on July 23, 2018, via link.
“Zebra Mussels.” Reduce Risks from Invasive Species Coalition, accessed on July 23, 2018, via link.
“Zebra Mussels.” New Jersey Department of Environmental Protection, accessed Aug 9, 2018, via link
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Papyrus and Phragmites: Invasive Species

By Bianca T. Esposito, NWNL Research Intern
(Edited by Alison M.  Jones, NWNL Director)

NWNL research intern Bianca T. Esposito is a senior at Syracuse University studying Biology and Economics. Her research this summer is on the nexus of biodiversity and water resources. Her earlier NWNL blogs were: Wild Salmon v Hatchery Salmon and Buffalo, Bison & Water.

 

My 3rd NWNL blog on biodiversity compares papyrus in Africa and phragmites in North America. I will highlight both flora’s ecological benefits, ecological threats and impacts to water, as well as solutions to prevent their uncontrollable spread.

Papyrus (Cyperus papyrus) is a tall, aquatic perennial shrub, ranging from 8 to 10 feet in height. This invasive species rooted into the ground, bearing simple brown fruit with brown/cream/green colored flowers, forms floating islands in tropical African swamps, rivers and lakes. In non-native habitats, papyrus will spread and invade the space of other native plants unless pruned. Commonly known as the “Paper Reed,” papyrus is native to Egypt and Sudan along the Nile River in North Africa, a NWNL case-study watershed. Papyrus is now also found in two other NWNL case-study watersheds: along Ethiopia’s Omo River (where damming has stabilized water levels allowing roots to take hold) and Tanzania’s Mara River Estuary.

Papyrus in Uganda .jpgPapyrus in Uganda (Creative Commons)

Once a well-known resource for paper making, today papyrus has potential for biofuel production. Papyrus also has many ecological benefits. Its value ranges from assimilating significant amounts of carbon dioxide from the atmosphere to providing breeding grounds for fish species, and feeding grounds for grazing herbivores.

In its native habitat, papyrus lines bodies of water, serving as a filtration system for removing sediments, sewage, and heavy metals that pollute the water. However, papyrus poses ecological threats to introduced environments, such as Italy and the United States, after being imported for ornamental use. Since it is invasive, papyrus disrupts ecosystems, threatens the growth of the native species, and impedes the flow of waterways. Papyrus will continue to expand problematically in introduced ecosystems if temperature warming continues to increase.

Jones_091003_TZ_1505.jpgPapyrus blooms in the Mara River Basin, Tanzania (© Alison Jones)

Major impacts papyrus has on non-native water ecosystems include: reducing native biodiversity by altering habitat; threatening the loss of native species; altering trophic levels; modifying hydrology; modifying natural benthic communities; and negatively impacting aquaculture and fisheries.

Solutions to prevent further papyrus spread into other ecosystems are the use of  physical, biological, and chemical controls. Physically, we could cut down and rake up the shrub. Biologically, we could use a novel fungal isolate that releases a phytotoxin to inhibit the growth of papyrus. And chemically, herbicides are a successful method to control papyrus spread.

Jones_091002_TZ_1209.jpgWoman collecting water in the Masurua Swamp with Papyrus in the background, Tanzania (© Alison Jones)

Phragmites (Phragmites australis) is a tall perennial grass that can grow up to 15 feet or more in height, with dense clusters of purple fluffy flower heads. Referred to as the “Common Reed,” this species is native to Eurasia and Africa. Our focus is on its impact in North America. Outside of its native habitat, phragmites is “cryptic invasive,” meaning that as this non-native species spreads within another native species’ range, it will typically go unnoticed due to its misidentification for the native species. Phragmites ideal habitat is marsh communities bordering lakes, ponds and rivers. Phragmites are present in the Columbia River Basin, Mississippi River Basin, and Raritan River Basin, the three North American NWNL case-study watersheds.

Jones_160414_NJ_3373.jpgPhragmites on the Raritan Bay, NJ (© Alison Jones)

The ecological benefits phragmites provide include improving habitat and water quality by filtration and nutrient removal, serving as shelter for birds and insects, as well as providing food for sparrows. Phragmites also help to stabilize soil against erosion. In light of climate change, this species is beneficial because its accretion rate keeps up with rising sea levels for protection.

Phragmites benefit marsh lands because of their ability to take up 3x more carbon than other native plants. When there is excessive carbon in the atmosphere sea level rises and allows for more frequent and intense storms, so keeping phragmites could help better protect marshes from rising sea levels and erosion. Phragmites also help build up more soil below the ground compared to native plants.

CT-NWK-514.jpgPhragmites at sunrise in Norwalk, CT (© Alison Jones)

Some ecological threats phragmites pose are as follows. Since phragmites grow in thickets by shallow water, they can displace native wetland plants, alter hydrology, and block sunlight from reaching aquatic communities. Phragmites decrease plant biodiversity, causing declines in habitat quality for fish and wildlife. This tall grass can also pose a driving hazard, as it blocks road signs and views around curves. Phragmites can also be a fire hazard when dry biomass is high during its dormant season.

The Neshanic River, a tributary of the Raritan River Basin, provides an example of the threats of non-native invasive phragmites. Here, it grows without regard to competition by suppressing regeneration of native vegetation and limiting biodiversity in the area.

Jones_120430_NY_1751.jpgPhragmites with redwings blackbirds on Long Island, NY (© Alison Jones)

Some solutions to combat the threats phragmites pose are similar to the methods used to control papyrus. Methods used include cutting or mowing the tall grass, applying herbicides (such as Glyphosate or Imazapyr), and controlling the spread of this invasive plant with molecular tools and fungal pathogens. Additional solutions would be to burn the plant, excavate the area, cover the area with plastic causing suffocation, increase plant competition in the area, increase grazing by herbivores, or use of biocontrol organisms (such as insect herbivores) to combat the spread of phragmites.

Whether in Africa or North America, we can see how detrimental non-native invasive plant species can be to the health of an ecosystem. Although papyrus and phragmites both have some positive benefits, they overwhelmingly impact aquatic habitats negatively with their spread. Thus many have concluded that the best thing to do is limit spread with the solutions suggested above, rather than attempt complete eradication. In some cases, they can become “guest invasives,” welcomed for the services they do supply, especially for wetlands and riverbank stabilization which minimizes storm damage.

 

Bibliography:
Morais, P. PubMed, accessed on June 13, 2018, via link.
Saltonstall, Kristin. PNAS, accessed on June 13, 2018, via link.
Swearingen, J. Invasive Plant Atlas of the United States, accessed on June 13, 2018, via link
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Sturtevant, R. Aquatic Nonindigenous Species Information System, accessed June 14, 2018, via link.
New Jersey Institute of Technology, The Neshanic River Watershed Restoration Plan, accessed on July 2, 2018, via link.
Oregon Department of Agriculture. Plant Pest Risk Assessment, accessed on July 17, 2018, via link.
Hauber, Donald P. Coastal and Estuarine Research Federation, accessed on July 17, 2018, via link.
Gaudet, John. Papyrus, accessed on July 23, 2018, via link.
Jackson, Harrison. Phragmites invasion: Detrimental or beneficial? Accessed on July 25, 2018, via link.

Cape Buffalo, Bison and Water

By Bianca T. Esposito, NWNL Research Intern
(Edited by Alison M.  Jones, NWNL Director)

NWNL research intern Bianca T. Esposito is a senior at Syracuse University studying Biology and minoring in Economics. Her research this summer is on the intertwined relationships of biodiversity and our water resources. This is Bianca’s second blog on Biodiversity for NWNL. Read her first blog on wild Salmon here.

This blog compares how water impacts the health of sub-Sahara’s Cape buffalo populations to how North America’s bison impact the health of our water resources.  This investigation covers three of our NWNL case study watersheds: Africa’s Mara and Nile River Basins, and North America’s Mississippi River Basin.

The Cape buffalo (Syncerus caffer caffer) is found in Kenya’s Mara River Basin savanna and Uganda’s Nile River Basin plains. The bison (Bison bison) used to dominate the Mississippi River Basin’s Great Plains and are still there in scattered small populations. Both species are large, herbivorous mammals that primarily graze on tall-grass ecosystems. However, their habitats and connections to water differ significantly.

Africa’s Cape buffalo migrate seasonally in large herds on cyclical routes dependent on fluctuations in water availability. They move out of areas with limited resources and into areas where moisture and nutrients are available. Cape buffalo also migrate away from their habitat when water levels increase, since flooding restricts their foraging abilities. In these cases, Cape buffalo move to a drier habitat where, in turn, they may experience drought. Either way, when resources become low, their vulnerability becomes high.

Jones_090927_K_9062.jpgA lone Cape Buffalo bull in Kenya’s Mara Conservancy (© Alison M. Jones)

Africa’s famed Serengeti-Mara Ecosystem is located throughout northern Tanzania and extends into Kenya. Much of this region is situated within the Mara River Basin. In the Serengeti National Park, the migration pattern of the Cape buffalo, similar to that of the wildebeest-zebra migration, is dependent on the fluctuation of rainfall each year. Generally, this journey begins in April when Cape buffalo depart their southern plains habitat to head north. This movement is triggered by the onset of heavy rain that floods the plains, reducing the Cape buffalo’s ability to graze. By May the herd is in the northwest Serengeti, where the dry season lasts through July and proximity to the equator allows rainfall to be more evenly distributed, allowing greater opportunities for foraging. Then, in August, the late dry season hits, causing the herd to move further north. On their venture north, they cross the Mara River into Kenya’s Maasai Mara National Reserve. The Cape buffalo remain here enjoying green pastures until November, albeit subject to drought if there’s no rainfall. In December, usually the first rainfall comes which they sense as the onset of the rainy season. They then trek back into Tanzania’s southern plains for the wet season. From January to April, they graze there on plentiful, nutritious grasses.  

Syncerus-caffer-Masaai-Mara-Kenya.JPGHerd of Cape buffalo in Kenya’s Mara Conservancy (Creative Commons)

When Cape buffalo inhabit dry lands their reproductive success (also referred to as “recruitment ability”) decreases; but their body condition improves due to what seems to be a fat-storing mechanism that anticipates limited future resources. One benefit of Cape buffalo having to cope with drought is that when food supplies are reduced, they forage through peat layers in dried-up underground channels, releasing nutrients otherwise trapped below ground.

A current major concern for this species is that anthropogenic factors (human activity) causing climate change are expected to increase both water levels and drought, which could push the Cape buffalo outside of their protected areas. In 2017, the Serengeti experienced a drought that lasted over a year causing declines in populations of many species, including Cape buffalo. Drought also causes herds of cattle, goats and sheep outside to enter protected lands to graze, creating a competition for resources between wildlife, livestock and humans in both the Maasai Mara National Reserve and Serengeti National Park. If the Mara River – the only major river in the area – dries up, there would be few resources for ungulates. As well, when droughts end, there is always potential for flash-floods which deter herds from crossing rivers to find greener pastures.

Jones_120107_K_0640.jpgA lone Cape Buffalo bull in Kenya (© Alison M. Jones)

When water is scarce in the Serengeti, a decline of Cape buffalo leads to increased lion mortality. When Cape buffalo lack sufficient food due to drought, they become weak and must travel increased distances to quench their thirst. This leaves the herd fatigued, causing some members to fall behind and thus become more vulnerable to predation. Also, after a drought and the rains begin, Babesia-carrying ticks infect Cape buffalo. Infected buffalo become weak or die, allowing easy predation by lions. Unfortunately, their carcasses transfer babesiosis disease to lions. Alone, this disease is not fatal to the lion. However, babesiosis coupled with canine distemper virus (CDV) is lethal.

Babesiosis from Cape buffalo has caused two major declines in Serengeti lion populations. In 1994, a third of the lion population was lost due to this combination, killing over 1,000 lions.

Lions_taking_down_cape_buffalo.jpgLions taking down a Cape buffalo (Creative Commons)

On a smaller scale, in 2001 the Ngorongoro Crater lion population also lost about 100 lions due to this synchronization of disease. Craig Packer, a University of Minnesota biologist, stated, “Should drought occur in the future at the same time as lions are exposed to masses of Babesia-carrying ticks—and there is a synchronous CDV epidemic–lions will once again suffer very high mortality.” He also warns that extreme weather due to climate change puts species at greater risk to diseases not considered a major threat before.  Fortunately, mud-wallowing that Cape buffalo use to cool down their bodies is also an effective shield against infiltrating bugs and ticks once the mud dries.

Overall, Cape buffalo rely heavily on rainfall patterns; but climate change is disrupting traditional migratory patterns by raising water levels or causing drought. Both extremes present negative impacts to the Mara River Basin and the biodiversity that inhabits it.  

North America’s bison – a bovine counterpart to African Cape buffalo – historically occupied The Great Plains west of the Mississippi River. Early settlers recorded 10 to 60 million bison openly roaming the fields. Like Cape buffalo, bison also migrate in search of food. Their migration paths used to cover vast territory, thus paving the way for many current roads and railroads. A major threat to  bison – as with most species – has been habitat loss due to human infringement, as well as well-documented, extensive hunting by new settlers heading west. By 1889, only approximately 1,000 bison remained in North America.

Jones_121024_TX_6814.jpgFarmed bison in Texas (© Alison M. Jones)

Due to recent conservation efforts, bison populations are rising; however, not to past numbers. Currently, they are found only in National Parks, refuges and farms. As of 2017, approximately 31,000 pure wild bison remain in 68 conservation herds. “Pure wild bison” are those not bred with cattle for domestication. However, only approximately 18,000 of the remaining population “function” as wild bison. This count excludes very small bison herds used for research, education and public viewing – or bison held in captivity waiting to be culled by protected areas such as Yellowstone National Park due to required limits.

Bison inhabiting the Mississippi River Basin, which drains throughout the Great Plains, have many positive impacts on its waterways and tributaries. Yellowstone Park, where the Yellowstone River drains into the Missouri-Mississippi River system, is the only place in North America where bison continue to freely roam as they used to. In Yellowstone, bison occupy the central and northern area of the park where they migrate by elevation, seasonally choosing food according to abundance, rather than quality. In the winter, they select lower elevations near thermal hot springs or rivers where there is less snow accumulation.

Bison positively affect water supplies when they wallow and paw at the ground. This results in intense soil compaction that creates soil depressions in grasslands. After many years, this soil depression tends to erode since bison don’t like to wallow on previously-created depressions. However, during the rainy season, wetland plants and vegetation grow in these wallows created by bison dust-bathing and trampling. For a short time many species enjoy these ephemeral pool habitats before they disappear in droughts or floods. Meanwhile bison wallows increase species diversity that would otherwise not be present in grasslands.

A_bison_wallow_is_a_shallow_depression_in_the_soil.jpgBison rolling around in a dry wallow (Creative Commons)

Bison have other positive impacts on water. As they trample through streams, they widen available habitat and alter water quality. Even after a bison dies, it can still contribute to the health of its ecosystem. Their carcasses are a nutritious food source for wolves, coyotes and crows. Studies suggest that bison carcasses take roughly seven years to fully decompose, during which time their remains release nutrients such as phosphorus and carbon into rivers. These nutrients sustain microbes, insects, fish and large scavengers of the area. A bison carcass can also provide sustenance for local fish since maggots, green algae and bacteria grow over their bones during decomposition. Bison carcasses also deposit nutrients into the soil which fertilizes plant regrowth.

Bison can negatively affect water resources, by decreasing native plant diversity due to overgrazing. However, they graze on only grass, which allows forbs (non-woody flowering plants) to flourish, adding biodiversity in grasslands. As well, when bison urinate, they deposit nitrogen into the soil, a key nutrient for grass growth and survival. Their urine also becomes a selectable marker allowing them to return to formerly-grazed pastures during the season. This constant reselection of grassland, allows combustion in ignored, non-grazed pastures, since fire tends to occur in tall grass with nitrogen loss. After fires, the bison are attracted to newly-burned watersheds because of C4-dominated grass which grows in dry environments. Bison select C4-dominated grassy areas because they have low plant diversity, unlike less-frequently burned sites where forbs are abundant. Thus, bison’s pasture preferences allow for more biodiversity, creating healthier watersheds.  

Jones_121024_TX_7314.jpgMural near of Native Americans on bison near Masterson, Texas (© Alison M. Jones)

Each of these two similar bovine species have significant, but different, relationships to water availability and quality within their river basins.  The African Cape buffalo migration is guided by water fluctuations. This could impact their future since anthropogenically-caused climate change could incur longer and more frequent droughts and increased flood-water levels to an extent that would drive Cape buffalo out of their protected habitats. In contrast, North American bison herds improve the health of waterways in the Mississippi River Basin in several ways. Nutrients from their decomposing carcasses add to the health of tributary streams and rivers; and their mud wallows support greater diversity of wetland and grassland flora.

Whether we look at watersheds in Africa or North America, it is clear that it is as important to study how biodiversity is affected by water availability, as how watershed water quality and quantity affects its biodiversity. Any changes to these ecosystems due to climate change could drastically affect the biodiversity and health of these watersheds.

Bibliography:

Briske, David. Springer Series on Environmental Management, accessed June 19, 2018, via link.
van Wyk, Pieter. MalaMala Game Reserve Blog, accessed on June 19, 2018, via link.
Bennitt, Emily. Journal of Mammalogy, accessed on June 19, 2018, via link.
Wilcox, Bradford. Springer Series on Environmental Management, accessed June 19, 2018, via link.
Chardonnet, Philippe. Gnusletter, accessed on June 19, 2018, via link.
Defenders of Wildlife, accessed on June 20, 2018, via link.
Coppedge, Bryan R.
The American Midland Naturalist, accessed on June 20, 2018, via link.
Polley, H. Wayne.
The Southwestern Naturalist, accessed on June 20, 2018, via link.
Crow, Diana.
Smithsonian, accessed on June 20, 2018, via link.
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American Institute of Biological Sciences, accessed on June 20, 2018, via link.
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Defenders of Wildlife, accessed on June 26, 2018, via link.
Yellowstone National Park, accessed on June 26, 2018, via link.
Huffman, Brent. Ultimate Ungulate, accessed on June 26, 2018, via link.
Department of Primary Industries, accessed on July 9, 2018, via link.
Popescu, Adam. New Scientist, accessed on July 9, 2018, via link.
Hoagland, Mahlon B. Exploring the Way Life Works: The Science of Biology, accessed on July 9, 2018E, via link.
White, PJ. Yellowstone Association, accessed on July 9, 2018, via link.

World Wetlands Day 2018

World Wetlands Day – February 2, 2018
blog by Sarah Kearns, NWNL Project Manager

BOT-OK-107.jpgOkavango Delta, Botswana, Africa

What are “wetlands”?

Synonyms: Marsh, fen, bog, pothole, mire, swamp, bottomlands, pond, wet meadows, muskeg, slough, floodplains, river overflow, mudflats, saltmarsh, sea grass beds, estuaries, and mangroves.

Jones_070605_BC_1624.jpgDevelopment on edge of Columbia Wetlands, British Columbia

Worldwide, wetlands regulate floods, filter water, recharge aquifers, provide habitat, store carbon, and inspire photographers & artists.

Jones_111024_LA_8655.jpgCyprus trees in Atchafalaya River Basin Wetlands, Louisiana

Wetlands control rain, snowmelt, and floodwater releases: mitigation that is more effective and less costly than man-made dams. Nearly 2 billion people live with high flood risk – This will increase as wetlands are lost or degraded.

Jones_091004_TZ_2124.jpgFishing boats among invasive water hyacinth in Lake Victoria, Tanzania

Wetlands absorb nitrogen and phosphorous which provides cleaner water downstream for drink water supplies, aquifers and reservoirs.

Jones_091002_TZ_1209.jpgWoman collecting water in Maseru Swamp, Tanzania

Wetlands absorb heat by day and release is at night, moderating local climates.

Jones_111021_LA_2490.jpgRed-earred turtles in Bluebonnet Swamp, Baton Rouge, Louisiana

We all need the clean air, water, and protection from flooding that wetland forests provide. But up to 80% of wetland forests in the US South have disappeared. What are our standing wetland forests worth? Let’s be sure we invest in our wetland forests. (From dogwoodalliance.org)  Worldwide, we must protect our wetlands.

Jones_150817_AZ_5849.jpgSouthern tip of Lake Havasu and incoming Williams River and its wetlands, Arizona

To learn more about World Wetlands day visit http://www.worldwetlandsday.org.

All photos © Alison M. Jones.

 

Glaciers: A Photo Essay

Edit (9/27/17): Since publishing this blog, the Washington Post reported the calving (or splitting) of a key Antarctic glacier, the Pine Island Glacier.  The article states, “the single glacier alone contains 1.7 feet of potential global sea level rise and is thought to be in a process of unstable, ongoing retreat.”  To learn more about how climate change contributed to this calving, and what the affects will be, read the article here.

 

“The alarming rate of glacial shrinkage worldwide threatens our current way of life, from biodiversity to tourism, hydropower to clean water supply.” (climatenewsnetwork.net)

During and in between NWNL’s dozens of expeditions to its six case-study watersheds, we have explored the value and current condition of glaciers on three continents, since they are a critical source of freshwater.  NWNL visited the Columbia Icefields of Alberta, Canada in 2007; Argentine glaciers in 2003 and 2005; and Rebman Glacier on the summit of Tanzania’s Mt Kilimanjaro in 2003.   We have witnessed the effect of climate change on glaciers. The melting of glaciers will affect  all forms of water resources for human and wildlife communities.  Just as upstream nutrients and pollutants travel downstream, “the loss of mountain ice creates problems for the people who live downstream.” Glacial loss must be thought of as just as important in the climate-change discussion as flooding and drought have become.

 

Jones_030809_TZ_0745Climbing Mount Kilimanjaro via the Machame Route. Tanzania, East Africa. (2003)

 

Jones_050402_ARG_0155Hole in ice of Lake Viedma Glacier in South Patagonia’s Glacier National Park, Argentina. (2005)

 

Jones_070609_ALB_2357Sign marking the former edge of the glacier. Columbia Icefields, Alberta, Canada. (2007)

 

ARG SC LVgla 059DA.tifLake Viedma Glacier at Glaciers National Park in Southern Patagonia, Argentina. (2005)

 

Canada: Alberta, Columbia Icefields Center Bus Tour, Athabasca GlacierAthabasca Glacier in Columbia Icefields. Alberta, Canada. (2007)

 

ARG SC Azul 004DA.tifGlacier melting and pouring into Blue Lake in the Andes Mountains. Southern Patagonia, Argentina. (2005)

 

Posted by Sarah Kearns, NWNL Project Manager.

All photos © Alison M. Jones.

 

Happy World Elephant Day!

For 30 years NWNL has studied Kenya’s iconic, charismatic jumbos that create water access for so many other species in the Mara River Basin. What can you do to celebrate and help elephants?
(scroll down for a few ideas 🙂 )

Participate in the #elegram project ———> and tell others to participate too!

Screen Shot 2015-08-11 at 2.56.47 PM

Send an E-Card for World Elephant Day!

Check out the World Elephant Day website for updates and news 🙂

Zambia:  Jeki, elephant ("Loxodonta africana") crossing Zambezi R.
Zambia: Jeki, elephant (“Loxodonta africana”) crossing Zambezi River
Kenya: Maasai (aka Masai) Mara National Reserve, Mara Conservancy, Mara Triangle, Trans Mora aerial (from helicopter), elephant near muddy tributary of Mara River,
Kenya: Maasai Mara National Reserve, Mara Conservancy, elephant near muddy tributary of Mara River

After all, aren’t clouds just recycled water?

Kenya: Trees clouds landscape
Kenya: Trees clouds landscape
Tanzania:  Zanzibar, Indian Ocean and cumulus cloud, sunset
Tanzania: Zanzibar, Indian Ocean and cumulus cloud, sunset
California: Yosemite National Park, Half Dome at sunset
California: Yosemite National Park, Half Dome at sunset
Tanzania:  Zanzibar, Indian Ocean and local fishing boat
Tanzania: Zanzibar, Indian Ocean and local fishing boat

What’s the WATER CYCLE?

– Posted by Jasmine Graf, NWNL Associate Director