Beyond the Reaches of Sunlight

It was 1843 when British naturalist Edward Forbes declared life in the ocean cannot exist below 300 fathoms (1800 feet).  Ten years later American naturalist Louis F. de Pourtales of the U.S. Coast Survey found indications of life in depths over 1000 fathoms (6000 feet).  It was 1867 when Louis F. de Pourtales found conclusive evidence of deep-sea life while conducing dredging operations off the southern coast of Florida.  Thanks to new technology and deep-sea submersibles we have discovered so much more about the ocean floor such as hydrothermal-vent communities, bioluminescent organisms, the Giant Squid, and deep-water corals.

At one time it was believed coral polyps only lived in the shallow-waters of the tropical regions of the world.  More than 250 years ago fisherman discovered evidence of coral living below the euphotic zone.  The past few decades scientists are discovering the true value of these deep-water corals as they explore below the euphotic zone of the ocean in their deep-sea submersibles.  Just recently scientists discovered an 85-mile stretch of deep-water coral off the coast of South Carolina.

Deep-water corals are also known as cold-water corals compared to the shallow-water or warm-water corals of the tropics.  Deep-water corals are found all over the world including Antarctica and have been found up to 20,000 feet below the surface of the ocean (that is more than 3 miles).  Deep-sea submersibles have discovered deep-water coral living in water as cold as -1oC (30.2oF).  Half of all known coral species in the world are from deep water.

Unlike their “cousins”, the shallow-water corals, deep-water corals do not have zooxanthellae which provide them food as part of a mutualistic relationship.    Deep-water coral obtains their energy needs by trapping tiny organisms and detritus (marine snow) as it drops from above and is passed along in the deep ocean current.  These sessile organisms can capture food floating by because they are fan-shaped and have increased their surface-area.

Besides providing habitat for important ecologically and economically fish, deep-water coral and the sponge communities they support may be a source of compounds for the development of new drugs and medical treatments.  The green Latrunculia austini sponge found living along side deep-sea corals contains molecules which specifically target and kill pancreatic tumor cells.

Deep-water corals are just as affected by ocean acidification as shallow-water corals.  Other threats to deep-water coral is bottom-trawling, mineral extraction, oil and gas exploration, and cable trenching.  One can imagine the damage done by bottom-trawling by observing what a forest looks like after they bulldoze the trees to put in a subdivision or shopping mall.

There is so much more we must learn about the deep-sea.  What will be discovered next and how will it benefit humans? 

Do you want to know more?


Wetlands…Nature’s QuikTrip

What is a wetland?  Wetlands have many names such as swamps, marshes, bogs, sedge meadows, wet prairies, fens, and seeps.   No matter their name, they share these three characteristics: wetland hydrology, hydrophytic vegetation, and hydric soils.

But have you ever heard of wetlands called “Nature’s Sponges”, “Nature’s Kidneys”, “Biological Supermarkets”, or “Nature’s Gas Stations?”  Wetlands provide many ecosystem services.  Wetlands act like sponges because their massive organic matter can absorb and store water for a long time.  This ability to store water helps to recharge groundwater and serve to help reduce damages caused by flooding.  Wetlands unique soils have a high cation exchange capacity which allow wetlands to remove pollutants and nutrients from the water as it flows through.  Wetlands can support a diversity of organisms thanks to the variety of food resources they provide for the animals who use wetlands part or all their life.

My favorite ecosystem service wetlands provide are “Nature’s Gas Stations.”  Today when you visit a QuikTrip you can fill up your vehicle with fuel, go inside get a snack (some stores you can get lunch or dinner) and purchase a refreshing beverage to quench your thirst.  Migrating birds around the world use wetlands as their fueling stations.  Some birds such as the Sandhill Cranes can be observed resting and feeding along rivers and wetlands throughout the Great Plains and Pacific Northwest.  Some Sandhill Cranes migrate over 2100 miles travelling about 250 to 350 miles per day.  This means they need several “gas stations” along their migration path to satisfy their hunger and thirst needs.

Our wetlands around the world are in trouble.  Wetlands are drained and filled for either agricultural needs or urban sprawl.  In Gwinnett County, Georgia, several wetlands are now covered with parking lots and shopping centers.  Although more than half of U.S. wetlands have been destroyed or degraded there is still hope.  Wetland restoration projects are happening everywhere.  Organizations and companies are also creating artificial wetlands because of the ecosystem services they provide.

How can you help?  Volunteer to help with a wetland restoration project.  You can purchase a Federal Duck Stamp from your local post office to help support wetland acquisition.  And you can educate others about the value of wetlands.

Is there life on Earth without the biogeochemical cycles?

The living components on Earth can survive because all the chemical elements which make up living cells is recycled continuously.  This recycling is done through our biogeochemical cycles.  We have the gaseous cycles which include nitrogen, oxygen, carbon, and water; and sedimentary cycles which include iron, calcium, phosphorus, sulfur, and other earthbound elements.

These elements within biogeochemical cycles flow from biotic components to abiotic components and then back.  The abiotic portion of a cycle is generally slower than the biotic portion.  For example, phosphorus in rocks is very slow to be released because weathering of rocks can take a long time.  But once the phosphorus is available it is used by a plant such as a blueberry bush for growth.  The blueberries from the bush can be then eaten by a black bear.  The black bear will do what bears do in the woods and the phosphorus which is not used by the bear for cellular processes can be passed back to the soil.

And the biogeochemical cycles do not act independently of one another.  Nutrients such as phosphorus and nitrogen are released by erosion of rocks and decomposition of organic matter in a river and then flow downstream thanks to the water cycle.  These nutrients can support the growth of aquatic plants which provide oxygen and food for aquatic organisms.

The next time you sit down to eat dinner think about where your food came from and the different biogeochemical cycles which made this meal possible.

Why should we care about biodiversity?

Biodiversity exists on three scales: ecosystems, species, and genetic.  Biodiversity is a key indicator of the health and stability of an ecosystem.  An ecosystem consisting of a variety of populations which are genetically diverse will cope better when threatened by pollution, climate change, or human activities.  Healthy biologically diverse ecosystems are resilient to change and more able to adjust to disturbances.

Healthy ecosystems and their species perform important ecosystem services.   Plants remove carbon dioxide from the atmosphere and release oxygen which helps keep the environment healthy and fit for human life.  Vegetative cover also helps to protect soils from erosion and desertification. 

Biodiversity provides us with an array of foods and materials and it contributes to the economy. Without a diversity of pollinators, plants, and soils, our supermarkets would have a lot less produce.  Wild varieties of domesticated animals and crops are also crucial as some will have already solved the challenge of, for example, coping with drought or salty soils.

The sheer richness of biodiversity also has human benefits. Many new medicines are harvested from nature, such as a fungi that grows on the fur of sloths and can fight cancer.  Alonin from Aloe plants is used in as an ingredient in lotions and gels to soothe burns, including sunburns.  The Madagascar periwinkle is the source of drugs used treat diabetes and certain cancers, such as Hodgkin’s disease and acute leukemia.

Aldo Leopold said it best, “When we see land as a community to which we belong, we may begin to use it with love and respect.” 

Protecting biodiversity will help lead to more stable and healthy ecosystems.  This is what we all need.

Negative population growth…good for the environment, bad for the economy?

Some people think the planet has surpassed its carrying capacity for humans while others believe the planet can handle more people thanks to our innovative ways to grow and provide food for everyone.  As a country progresses through the demographic transition model (DTM) the birth and death rates decline.  But what happens when a country reaches beyond stage 4 of the DTM?  Stage 5 of the DTM means a country is experiencing what some call a negative population growth.  Negative population growth can mean the country is experiencing a higher death rate than birth rate.  The higher death rate is due to a population which is growing older and older.  Examples of countries currently experiencing negative population growth are Japan, Germany, Russia, Ukraine, and Greece.

Isn’t negative or zero population growth what we wanted?  Well…think about this.  How do we pay for services such as education, police, fire, medical, and other services?  The working population pays taxes which contribute to our infrastructure, pension systems, and health care systems.  An ageing population will certainly increase the pressure on our health care systems with a higher demand for doctors, nurses, and medical supplies.  Economic growth will decrease for a country which has less workers and more retirees.  Less workers means less people to purchase goods and services.

How would a country solve the problem of negative population growth?  Some countries have encouraged immigrants to choose their country to work and live.  Other strategies include incentives to have more children like additional monthly pay for the family and paid maternity/paternity leave.

There is no simple solution to human population growth rate.  Solutions come with consequences. 

Who speaks for the trees?

What do you see when you look at a tree?  In some cultures, trees represent courage and strength.  In science we see a tree as a producer of oxygen, habitat for birds, a storage container for carbon, a windbreaker, a climate controller, a soil protector, and an umbrella of shade.  Forest and woodland ecosystems perform many important ecosystem services which are free of charge. 

The more diverse the forest ecosystem, the more variety of ecosystem services it can provide.  Deforestation reduces biodiversity and thus reduces the ability for the forest to moderate erosion of soils, protect water from pollution, provide firewood for cooking, and provide habitat and nutrition for wildlife.

Many years ago, Kenya’s forests were being cut down leading to desertification in some areas along with sediment pollution in its streams.  Additionally, many citizens of Kenya depended upon the forest to provide them with the firewood they needed to cook their food and warm their homes.

One of my heroes, Wangari Maathai, launched the Green Belt Movement in 1977 to reforest Kenya and at the same time empower the women of Kenya.  The program has been managed by the women in the villages of Kenya and they have learned to work together to grow seedlings and plant trees to bind the soil, store rainwater, and provide food and firewood.  Through their efforts they have become more educated about how to protect their environment while at the same time earning money which allowed them to better care for their children and their children’s future.

The Green Belt Movement is responsible for planting more than 35 million trees and providing more than 30,000 women with new skills and opportunities.  Wangari Maathai was awarded the Nobel Peace Prize in 2004 for her “holistic approach to sustainable development that embraces democracy, human rights, and women’s rights.”

Although she was arrested, harassed, beaten, and called names she never gave up the fight for what she thought was the right thing to do.  In her memoir she wrote “What people see as fearlessness is really persistence.”  Wangari is a prime example of how one person can be a force of change.  She symbolizes “think globally, act locally.”

“We cannot tire or give up.  We owe it to the present and future generations of all species to rise up and walk.” ~ Wangari Maathai

Will you rise up and speak for the trees?

Algal Blooms

This summer some of you might have heard about the algal bloom in Lake Okeechobee or the red tide along the shores of Southwest Florida near Tampa.  Algal blooms (algae blooms) are a natural phenomenon, but have increased in abundance due to anthropogenic activities.  An increase in human population have increased the addition of nitrates and phosphates entering our waterways. 

Algae are unique.  They have plant characteristics, but are not really plants.  Some people classify them as protists.  Either way, algae are very important because they play an important role in food chains and in the production of Earth’s oxygen supply.  But too many algae in a body of water can bring about devastating effects.  Algal blooms are a rapid increase in the population of algae in either freshwater or marine environments.  The population of the algae is so great that light penetration is minimized, and the water can be the color and texture of pea soup. 

Dead algae sink to the bottom of the lake or ocean where it becomes food for the bacteria that decomposes it.  As the dead organic matter increases so does the bacteria.  The bacteria can become so numerous they used up the dissolved oxygen in the water.  The decrease in dissolved oxygen can result in the death of fish and other aquatic organisms.

The rapid growth of blue-green algae (cyanobacteria) can release cyanotoxins resulting in what is known as a harmful algal bloom (HAB).  HABs can harm fish, other wildlife, livestock and pets, and threaten public health.  Red tides are HABs and this past summer have raised a lot of concerns for the citizens of Southwest Florida who live along the coast. 

Algal blooms are more prevalent during the summer months because of the longer days and higher temperatures.  Like plants, algae need sunlight, water, and nutrients to grow.  It is the overabundance of nutrients in our waterways causing algal blooms.  The excess nutrients come from fertilizer runoff, animal waste, chemical discharge and waste from industrial plants, urban sewage runoff.  Fertilizer runoff can come from agricultural fields and from residential neighborhoods.  The excess nutrients travel through the watershed eventually leading to a lake or an ocean.

See the source image

Phytoplankton are one type of algae and are the base of the aquatic food chain (the producers).  Primary consumers will feed upon the phytoplankton and secondary consumers feed upon the primary consumers.  Phytoplankton are essential to the health and productivity of our aquatic systems.  We need to do our part to help mitigate the sources of excess nutrients and prevent algal blooms.