Select Page
Eek! What is that Sheen on My Water?

Eek! What is that Sheen on My Water?

Spring is a time of change. Spring brings changes in our waters as well. Some of these changes are visible on top of the water and cause concern among water users and viewers. Let’s dispel some of these concerns associated with the spring season.

Sometimes, water users and viewers notice what appears to be oil floating on top of the water. Could this be oil? Potentially. Could this not be oil? Most likely. Plants perish, and decomposition occurs, typically during the spring and fall seasons of the year. Much of the decomposition that happens in spring is associated with the initial growth and development of plants. Bacteria living in the soils within and around the water break down the perished plants. These bacteria are decomposing the old plant material. The waste product produced from the bacteria’s decomposition of the old plant material is an oily substance. The oily sheen on the water is a waste product of bacteria. Frequently, the oil accumulates in portions of water where there is little to no water movement. As the decomposition process completes, the oily sheen should lessen over the next few days to weeks. This bacteria-produced oil from decomposition is a natural process.

Petroleum-based oil seen on water is not a natural process. Petroleum-based oil could enter water from various sources, such as but not limited to transportation spills, stormwater runoff, and improper disposal of products containing oil. Like the oily substances produced by bacteria during decomposition, petroleum-based oils will float on top of the water and accumulate where there is little to no water movement.

Here are some tips to identify the difference between oils in water:

Bacteria-produced Oil Petroleum-based Oil
Appearance Oily sheen on top of water with little to no difference in color throughout Oily sheen on top of water with differences in color throughout (may even appear like a rainbow)
Touch

(use a stick)

When disturbed, the sheen breaks away easily with irregular patterns and does not reform. The oil will not adhere to the stick. When disturbed, the sheen swirls, elongates, and does reform. The oil may adhere to the stick.
Odor

(not always present)

Strong organic, musty, or earthy smell. Volatile organic compounds (VOCs) smelling like gasoline or diesel fuel.

Another sheen on our waters that is frequent during Florida’s springtime is pollen. Pine, tree, and weed pollen accumulate on top of water, especially in areas with little or no water movement. If the sheen on the water is yellow, orange, or sometimes white, this is most likely due to pollen. Think about how pollen shows on a car in Florida during spring…our waters can show the same to some extent.

Let’s give it a try! See if you can identify the sheens in water in each photo—answers at the bottom of the page.

Photo 1

Photo 2

Photo 3

Photo 4

Whiteish-orange pollen accumulated on top of water.

Photo 5

Petroleum-based oil sheen on top of water.

Photo 6

Oily sheen on water produced by bacteria decomposing plant material.

Keep Scrolling For Answers!

.

.

.

.

.

.

PHOTO ANSWERS: Photo 1: Bacteria-produced oil sheen. Photo 2: Pollen sheen. Photo 3: Petroleum-based oil sheen. Photo 4: Pollen sheen. Photo 5: Petroleum-based oil sheen. Photo 6: Mixture of bacteria-produced oil and pollen sheen. Note all photos were obtained from Adobe Stock Photos.

Marine Creatures of the Northern Gulf – Brown Algae

Marine Creatures of the Northern Gulf – Brown Algae

If green algae are difficult to find in the northern Gulf because most prefer freshwater, and rocky shorelines, brown are difficult because the group prefers colder water, as well as rocky shorelines – but we do have some here.

Brown algae get their color because the ratio of photosynthetic pigments in their cells favors the xanthophylls – which produces a yellow-brown color.  Like most macroscopic algae, they attach to the hard bottom using a holdfast and then extend their stipe and blade into the water column to absorb light.  One group of brown algae are the largest of all seaweeds, the giant kelp Macrocystis.  In the nutrient rich waters off California this seaweed will grow up to one foot a day and can reach heights of up to 175 feet tall.  Since seaweeds do not possess true stems, or any wood, what holds this giant seaweed up are air filled bladders called pneumatocysts – structures found on other brown algae and are unique to the group.

The largest, fastest growing seaweed – giant kelp.
Photo: NOAA

Many species are popular with seafood dishes, such as Nori.  Others produce a carbohydrate known as algin that is extracted and used as a food additive.  You may have heard “ice cream has seaweed in it”.  What it actually has is algin.  This carbohydrate acts as a smoothing agent for products.  Solids should be solid – like frozen ice cream – but, as you know, we do not want our ice cream solid.  So, for a period of time, the algin keeps the ice cream smooth and creamy.  Algin is used in toothpaste, lipstick, and icing on cakes for the same reason.

But along the northern Gulf coast, brown algae are not common.  Despite preferring marine waters, they do prefer colder water and, like most seaweeds, need a hard substrate to attach their holdfast.  But by exploring our local rock jetties and seawalls we do find some.  One in particular is the common rock weed – Dictyota.  This sessile seaweed branches out and resembles small trees.  But the most common, and most recognized brown algae on our coast is Sargassum.

The brown algae Dictyota.
Photo: NOAA

Sargassum has found a way to deal with an environment where little hard bottom is present.  Using the characteristic air bladders allows it to float at the surface to absorb the much needed sunlight.  Because of this ability to float, Sargassum can be found all across the oceans, and often form large mats that cover miles of open sea and extend several feet down.  It actually creates a whole new ecosystem in the middle of the sea.  The major ocean currents rotate like a hurricane and, like a hurricane, the center – the “eye” – is calm.  Within this calm huge mats of Sargassum collect.  The ancient sailors called the center of the Atlantic Ocean the “Sargasso Sea”.  But as the large currents spin, sections of this large mat “spin off” and are pushed across the ocean.  Much of it heads towards Florida, the Gulf, and eventually to the northern Gulf.

If you grab a mask and snorkel and swim within the Sargassum before it reaches the waves, you will encounter a whole community of creatures that live here.  Sargassum crabs, Sargassum fish, and even seahorses live within it.  There are shrimps, worms, and even mollusks.  When baby sea turtles head offshore after hatching, many seek out these Sargassum mats to both hide in, and feed within.  They will spend their youth here before returning back to shore for different prey.

However, once many of these creatures sense the waves breaking, and now the mat is about to wash ashore, they will move to mats further offshore.  That said, picking through the Sargassum on the beach may still yield some interesting creatures.

Sargassum.

In recent years the amount of Sargassum washing ashore has increased and become problematic – particularly in southeast Florida and the Florida Keys.  At times, mounds three feet high have been found.  Those communities are working on methods to deal with the problem.  But here locally, these mats are a new world to explore.

References

Giant Kelp. Monterey Bay Aquarium. https://www.montereybayaquarium.org/animals/animals-a-to-z/giant-kelp.

Getting Your Farm Pond Ready for Spring

Getting Your Farm Pond Ready for Spring

As spring approaches, I’ve been receiving more calls from local pond owners looking for advice on preparing their farm ponds for the season. Managing a pond in the Florida Panhandle can be tricky—especially when dealing with spring-fed ponds. While these ponds are often beautifully clear, their constant water turnover makes management a challenge.

If you’re wondering how to get your pond ready for spring, here are some key considerations and resources to help guide you.

Start with a Water Quality Test

The first step in assessing your pond’s health is testing the water. I always recommend that pond owners bring a pint-sized water sample in a clean jar to their local Extension Office for analysis. Keep in mind that not all offices offer this service, and public testing options are limited. However, private labs and DIY testing kits are available—though they can be costly.

The most important parameters to check are pH, alkalinity, and hardness: pH should ideally range between 6 and 9 for a healthy fish population. Local ponds often hover around 6.5, making them slightly acidic.

Alkalinity and hardness measure the water’s ability to neutralize acids and buffer against sudden pH changes. For optimal pond health, alkalinity should be at least 20 mg/L, but many local ponds fall below this level.

Improving Pond Water Quality

If your pond’s water quality is less than ideal, there are two common ways to improve it: liming and fertilization.

Applying Agricultural Lime: Properly adding agricultural lime can raise alkalinity and stabilize pH levels. However, in high-flow ponds, lime tends to wash away quickly, making this method ineffective for ponds with constant discharge.

Fertilizing to Boost Productivity: Fertilization increases phytoplankton growth, which supports the pond’s entire food web, benefiting juvenile fish and invertebrates. Unfortunately, like lime, fertilizer is quickly washed out of high-flow ponds, making it ineffective in these cases.

Making the Best of Your Pond

If your pond has a continuous discharge due to spring flow, the best approach may be to embrace its natural clarity, even if it doesn’t support a thriving fish population. However, if your pond retains water without frequent outflow, you may be able to enhance its productivity with the right amendments.

For personalized guidance, contact your local UF/IFAS Extension Office. You can also start by reviewing this helpful fact sheet: Managing Florida Ponds for Fishing. By understanding your pond’s unique characteristics, you can make informed decisions to keep it healthy and enjoyable throughout the season.

Our Environment: Part 3 – Life in the Sea

Our Environment: Part 3 – Life in the Sea

They say life began in the oceans.  We know that the lithosphere is cracked, adding new land, subducting land over time.  But much of the lithosphere is covered with water – and here life began.  Initially it had to begin on either rock or sand.  The sand would have been produced by the weathering and erosion of rock.  Obviously, this would all have had to occur over a long period of time.  But the first forms of life would have to be able to find food and nutrition from a barren seafloor with little to offer.  This would take a special community of creatures – ones we call the pioneer community.

It is believed that life began in the ocean.
Phot: Rick O’Connor

Key members of these communities would have been the producers’ ones who produce food.  What we know now is that producers absorb carbon dioxide and water and – using the sun as a source of energy – convert this into carbohydrates and oxygen.  We have since learned that there are ancient forms of bacteria that can do this with hydrogen sulfide and other compounds.  However, it started – it began.  One problem with this model is that much of the world’s oceans are too deep for sunlight to reach.  Thus, living organisms would need to be close to shore.  Today we know two things.  One, the ocean’s surface is covered with microscopic plant-like creatures (phytoplankton) who can float and reach the sunlight. Two, some of the ancient chemosynthetic bacteria (those that do not need the sun and can use other compounds to produce carbohydrates) live on the ocean floor.

The black smokers – hydrothermal vents – found on the ocean floor.
Photo: Woodshole Oceanographic Institute.

Producers are followed by consumers, creatures who cannot make their own food and must feed on either the producers or on other consumers.  There are plankton feeding animals – oysters, sponges, corals, and zooplankton.  There are larger creatures that feed on larger plankton – manta rays, menhaden, and whales.  There are consumers who feed on the first order of consumers – stingrays, parrotfish, and pinfish.  And there are the top predators – orcas, sharks, and tuna.  The ocean is a giant food web of creatures feeding on creatures.  All creatures evolve defenses to avoid predation.  Predators evolve answers to these defenses.  Some species survive for long periods of time like the horseshoe crabs and nautilus.  Others cannot compete and go extinct.

Horseshoe crabs are one of the ancient creatures from our seas. Photo: Bob Pitts

As we mentioned in Part 1 of this series – the hydrosphere is in motion.  Different temperatures, pressure, and the rotation of the planet move water all over.  These currents bring food and nutrients, remove waste, and help disperse species across the seas.  Life spreads to other locations.  Some conditions are good – and life thrives.  Others not so much – and only specialists can make it.  The biodiversity of our oceans is an amazing.  Coral reefs, mangrove forests, and seagrass beds are home to thousands of species all interacting with each other in some way.  The polar regions are harsh – but many species have evolved to live here, and the diversity is surprising higher than most think.  The bottom of the sea is basically unknown.  It has been said we know more about the surface of the moon than we do at the bottom of our ocean.  But we know there is a whole world going on down there.  We believe the basic principles of life function there as they do at the surface – but maybe not!

The magical lights of the deep sea.
Photo: NOAA

Fossil records suggest life here began almost one billion years ago.  The fossils they find are of creatures similar and different from those inhabiting our ocean currently.  As we stated that the physical planet is under constant change – life is as well.  It is a system that has been working well for a very long time.  Over the last few centuries humans have studied the physical and living oceans to better understand how these systems function.  They have been functioning well for a very long time.  And though life began at sea – there was dry land to exploit – for those who could make the trip.  That will be next.

Marine Creatures of the Northern Gulf – Green Algae

Marine Creatures of the Northern Gulf – Green Algae

With this article we will shift from the microscopic creatures of the Gulf of Mexico to the macroscopic ones – ones you can see without a microscope.  We will begin with the simplest and most primitive of macroscopic creatures – the seaweeds.

Many locals see the grass washed ashore along the Intracoastal Waterway and call this seaweed, but it is in fact seagrass.  Seaweed differs from seagrass in that they are not true plants. True plants are vascular – meaning they have a series of “veins” running through their body called xylem and phloem.  These veins move water and material throughout the body – similar to the arteries and veins of an animal.  But seaweeds lack this “circulatory” system, rather they absorb water through their tissues and must live in the water environment to do this.  Seaweeds lack leaves, stems, and roots.  They do not produce seeds or flowers, but they do require sunlight and nutrients and conduct photosynthesis as true plants do.  When I was in college seaweed was considered simple plants – just nonvascular ones.  Today biologists believe they are too simple to be considered plants and thus are a group existing between the microscopic phytoplankton and the true vascular plants we know from our lawns and forests.  They are often called algae as well as seaweed.

Mats of Sargassum on a south Florida Beach.
Photo: University of Florida

Biologists divided the seaweeds into divisions based on their color, which is determined by the photosynthetic pigments they have for photosynthesis.  Compared to my college days, the classification of green algae is quite complex.  The entire group was once placed in the Division Chlorophyta.  Today, most sources consider only the marine forms of green algae in the group Chlorophyta, with numerous other groups consisting of thousands of species.  Most green algae live in freshwater and are believed to be the group that led to the land plants we are familiar with.  Their photosynthetic pigments include chlorophyll and a and b but also carotene and xanthophyll.  The pigments are dominated by the chlorophylls – hence their green color – and the ratio of chlorophyll to carotene and xanthophyll is the same as the plants you find in your yard – hence the argument they led to the evolution of land plants.

Green algae – or any of the seaweeds – are not as common along the northern Gulf of Mexico as you find on other coasts.  Not having true roots, stems, or leaves, seaweeds must attach themselves to the seafloor using a suction cup type structure called a holdfast.  To attach, the holdfast must have a rock of some type.  Along the rocky shores of Maine and California, they are quite common.  Even with the limestone rock of south Florida you can find these.  But the fine quartz sand of the northern Gulf of Mexico is not as inviting to them.  That said, we do find them here and most are found on man-made structures such as jetties, seawalls, and artificial reefs – I found one attached to a beer can.

Of all of the green algae that exist in Florida, I have only encountered three.  One is called “sea lettuce” in the genus Ulva.  Attached to rock jetties and seawalls, it looks just like lettuce and is beautiful, brilliant green in color.  It grows to about seven inches in height and is used as a food source in different countries.  It can become a problem if local waters are high in nutrients due to pollution from land sources.  It will grow abundantly, reducing habitat for other species, and wash ashore during storms where it breaks down releasing gases that can be toxic to shore life and humans.  I first encountered it growing on the rock jetties at St. Andrews State Park in Panama City, but it does grow on local hard structures.

Sea Lettuce.
Photo: University of California

“Dead Man’s Fingers” – Codium – is another green algae I first encountered it on the jetties of St. Andrews.  The thick finger-like projections of this seaweed extending from the rocks did resemble a glove – or the fingers of a dead man within the rocks.  Some species around the world are used for food.  But I could not find any references that it is here.

“Deadman’s Fingers”.
Photo: iNaturalist

The third species of green algae I have seen locally is known as the “Mermaids Wine Glass” – Acetabularia. This beautiful seaweed is relatively small and does resemble a wine, or martini glass.  They are quite abundant in south Florida and is the one I found growing on a beer can submerged in Santa Rosa Sound.   

“Mermaid’s Wineglass”
Photo: Project Noah

Though seaweeds in general are harder to find along the northern Gulf coast, they are fun to search for and do play a role as primary producers here.

 

 

References

Green Algae. Wikipedia. https://en.wikipedia.org/wiki/Green_algae.

Deadman’s Fingers. Monterey Bay Aquarium. https://www.montereybayaquarium.org/animals/animals-a-to-z/dead-mans-fingers.

Introduction to Green Algae. University of California/Berkley.  https://ucmp.berkeley.edu/greenalgae/greenalgae.html.

Ulva Lactuca. Wikipedia. https://en.wikipedia.org/wiki/Ulva_lactuca.