Aquatic Ecosystems – Page 7 – Clean Water Warrior

South Florida HAB outbreak all too predictable

Less than two months ago, Clean Water Warrior (CWW) noted that the Florida Keys, and the fragile coral reef surrounding them, were always at risk from Harmful Algae Blooms (HAB). These blooms are largely caused by hot weather and, just as importantly or perhaps even more so, rain-induced nutrient runoff from agriculture and communities.

Today, as the Army Corp of Engineers drains water from Lake Okeech0bee — the result of unusually heavy rains from the 2016 rainy season (tied, of course, to global warming) – South Florida is in a full-blown HAB crisis.

This quote, taken from CNN’s excellent July 1, 2016 coverage of the HAB crisis, tells the grim tale as well as any:

Jordan Schwartz, owner of the Ohana Surf Shop, said he wanted to cry when he saw the green slime — a toxic algae bloom — covering his swath of Stuart Beach on Florida’s east coast.

“Animals are in distress, some are dying, the smell is horrible,” he told CNN on Friday. “You have to wear a mask in the marina and the river. It’s heartbreaking and there is no end in sight. The economic impact is devastating,” he said. “This town is 100% driven by tourism but the tourism is empty,” he said. “You go to the beach and it’s the height of summer and we have empty beaches, empty restaurants, empty hotels.”

The typical rogues gallery of offenders, which working in concert typically explain why HAB’s appear,

STuarts_FL-Docks_Algae — Algae-covered water at Stuart’s Central Marine boat docks

is again at work. Too much rain,creating too much runoff, flowing with too few natural or man-made restrictions into waterways that eventually pour too much phosphorus and nitrogen into slower moving waters, lakes, and, in this case, ocean shoreline.

Bottom line: the best chance of reducing HABs is to control what can be controlled. Rain? No. Man-made construction to re-route water, dam, or chemically alter? Maybe — but at an often exceedingly high price. Reduction of nutrients applied to land? Yes. Creating large land buffers to capture much more of the nutrients before they enter the waterways? Yes.

And it is with the last two solutions that Florida must start. Cooperation, not finger-pointing, is the key.

Hot, Hotter, Hottest – and here come the blooms.

I’ve been reading lately from sources such as the EPA and NRDC that climate change, in particular the heavy rains and hotter temperatures, is a primary contributor to the increase in toxic algae blooms seen around planet Earth. As I read, I was hoping to discover what percentage of blooms can be explained by hotter temperatures — and the correspondingly warmer waters that stimulate bloom activity.

Unfortunately, it appears that no matter how you try to slice the pie chart, hotter temperatures, more heavy rain, and drought — which I won’t touch on here — all work together to create a nasty cocktail upon which algae greedily gulps. Simply put, wherever Harmful Algae Blooms (HAB) exist, you’ll find at least two of the aforementioned conditions working together.

Which brings me to my point. In the terrific white paper Tides of Trouble from the NRDC website, the first “what to do” item proposed is to implement methods to control nutrient runoff from cities and farms, etc. Proven methods, I might add.

As I’ve said many times before, there is no one solution to the global problem of HAB in waterways. But, wherever HAB’s do exist, controlling nutrient run-off is often cited as the most effective first line of defense.

Shallow Lakes Can Survive Ecological Threats

With my son heading today to the Midwestern vacation hot spot Wisconsin Dells, it seems like a good time to check on the condition of one of that area’s biggest attractions: Lake Delton.

For over 60 years this lake, which is home to Tommy Barlett’s wildly popular water shows, has been a flagship tourist draw to The Dells. Beaches and condominiums line the 250-acre man-made lake, the primary inflow for which is Dell Creek; with an outflow to the Wisconsin River.

But the lake is not without its problems. With an average depth of just 10 feet, and only about 20 feet at its deepest point, Lake Delton has algae problems. So much so, that lake area residents and the Village of Lake Delton in 2012 approved injecting blue dye into the lake, to make it prettier for residents and tourists alike.

Ahhh, the benefit of tourist dollars and sizable resources.

Well, the question begs, doesn’t it? If Lake Delton can struggle with toxic algae, what chance do other small and shallow lakes have?

Not that bad, it appears.

In this excellent article on shallow lakes ecology, by Dwight Osmon — a Water Research Planner for ecology engineering firm Hey and Associates — there are some rules of thumb to follow that give shallow lakes a chance to be cleaner and more naturally viable for people, plants and fish alike.

Promoting native plant life at the bottom of a shallow lake appears to be key.

Here is some of what Osmon presents as a multi-pronged solution:

Make an effort to, ironically and when applicable, lower the water level of the lake to permit sunlight to reach the lake bottom, and facilitate plant growth.
Eliminate carp via commercial fishing, and the introduction of predatory game fish such as Walleye and Pike.
Create larger no-wake zones to reduce wave activity — or eliminate the wake activity from boats altogether.
Control nutrient loading into the lake from sources such as farms and residential properties.

Osmon emphasizes that these approaches work best when implemented simultaneously. Certainly, together they represent a better option than adding blue dye.

Florida Keys? No Immunity From Nutrient Runoff

It is more than a guilty pleasure. I am an addict for watching the terrific Netflix Original Series “Bloodline.” So much so, that I just had to explore how, or if, nutrient runoff is having an impact on the Florida Keys’ beautiful and environmentally fragile area.

What I found is typical and, at least for me in this case, disheartening.

Despite the myriad abusers of the only continental coral reef in the United States, a reef that is third in size only to those that exist off the coasts of Australia and Belize, its number one threat remains nutrient runoff.

This passage from Reef Relief Founders is particularly unsettling:

Corals require clean, nutrient-free waters to thrive. A healthy coral reef has from 30-40% live coral coverage. However, in the Florida Keys, coral coverage is now reduced to an alarming 3%. Coral spawning has been reduced due to lack of healthy coral colonies and clean water.

The over-abundance of nutrients in the ocean is the single biggest threat to Florida’s coral reefs. Nutrients is a scientific term for organic and inorganic materials that can include phosphates, and/or nitrates, usually from untreated and partially treated sewage, fertilizers and other pollutants. They promote algal blooms which rob the water of oxygen and compete with corals for habitat. Every year, 700 tons of nutrients are discharged into Keys waters from agricultural run-off from the Everglades. Another 33 tons of land-based sources of pollution are discharged from the landbase in the Keys, primarily from inadequately treated sewage and stormwater. Harmful algal blooms can result in eutrophication, when oxygen levels become so low that fish and other marinelife cannot survive.

With a nutrient discharge of 700 tons, Everglades agricultural runoff dwarfs the relatively meager 33 tons coming from land-based communities in the Keys.

As ever, however there is encouraging news. This time coming from a three-year Oregon State University study. The results? Reduce pollution, particularly nutrient runoff — which is relatively easy to accomplish, the study says, through improved sanitation and best farming practices — and the Florida Keys reefs make a dramatic comeback.

In as little as one year.