by Rick O'Connor | Nov 8, 2024
Remaining in the world of the microscopic, in this article we look at small plant-like creatures called diatoms. Diatoms are single celled algae that float in the surface waters of the Gulf of Mexico in the billions. Being plant-like, they possess chlorophyll for photosynthesis. In fact, they possess two forms of chlorophyll, and another photosynthetic pigment called fucoxanthin. Chlorophyll gives plants their characteristic green color, fucoxanthins are more yellow in color and give the diatoms the common name green-yellow algae.
Silica covered diatoms.
Photo: NOAA
To collect them scientists pull what is called a plankton net. This net is funnel shaped with the diameter of the large opening being from several inches to several feet. The mesh is of a cloth material with extremely small holes to allow water to pass but not the plankton. The plankton net is deployed off the stern of the ship/boat and towed slowly at a specific depth. Once back on board the sample can be observed in a microscope.
Plankton net.
Photo: NOAA
Diatoms are one of the more abundant microscopic plant-like algae called phytoplankton. They differ from other phytoplankters in that they do have the yellow-green color to them, but they also possess a clear glass-like shell called a frustule. This frustule is made of silica and comes in two parts. The top half is called the epitheca and the bottom half the hypotheca. The two halves fit together like the two plates of a petri dish. This frustule often has spines extending from it giving the diatom the appearance of a snowflake – and under the microscope they are beautiful. These spines actually serve a purpose. It is important they remain near the sunlit surface. To reduce sinking, these spines increase their surface area creating drag and reducing the chance they will sink. Most also produce gas pockets within the cytoplasm to make them more buoyant.
The spherical shape of the centric diatom.
Image: Florida International University
All diatoms are subdivided into two groups based on their frustule shape. Some have circular frustules and are called centric diatoms. Others are more elongated and are called pennate diatoms. Scientists currently estimate there are between 100,000 and 200,000 species of them. Though they are abundant in all the world’s oceans, they seem to be more abundant in cooler waters.
To say they play an important role in ocean ecology is an understatement. Between them and their other phytoplanktonic cousins – phytoplankton produce about 50% of the world’s oxygen. In an open ocean environment like the Gulf of Mexico where the seafloor is beyond the reach of the sun, diatoms, and other phytoplankton, are referred to as the “grasses of the sea”. They are the base of almost all marine creature’s food chain.
A phytoplankton bloom seen from space.
Photo: NOAA
When diatoms die (which is often in less than a week) their silica shells will eventually sink to the seafloor forming a layer of silica called “diatomaceous earth”. This sediment layer is commercially important as an abrasive. You will see diatomaceous earth labeled on toothpaste, household cleaners, soaps, anything with a little grit in it to help clean. It is also used in air and water filters to help purify such. You find these filters in aquariums, swimming pools, and hospitals.
If you collect a glass of water from the Gulf you are not going to see them without a microscope but know that the glass is full of these beautiful, amazing, and important marine creatures of the northern Gulf of Mexico.
by Rick O'Connor | Oct 25, 2024
In the first article of this series, we discussed whether viruses were truly living organisms. Well, bacteria truly are. They possess all eight characteristics of life but differ from other forms of life in that they lack a true nucleus. Their genetic material just exists in the cytoplasm. This difference is large enough to place them in their own kingdom – Monera.
The spherical cells of the “coccus” bacteria Enterococcus.
Photo: National Institute of Health
Bacteria are single celled creatures, though some “hook” together to form long chains. A single cell will average between 5-10 microns in size. This is much larger than a virus but smaller than many eukaryotic cells (those that possess a nucleus).
To further classify bacteria microbiologists will conduct a gram-stain test. Placing a cultured sample of bacteria on a slide, you “bath” them in what is called Gram-stain. Under the microscope the bacteria that appear “pink” are called gram negative, those that appear “purple” are gram positive. Thus, all bacteria can be quickly grouped into those that are gram negative and those that are gram positive.
After staining, gram negative bacteria appear pink in color; gram positive are purple.
Image: University of Florida
The next level of classification focuses on the shape of their cells. Those that are “rod-shaped” are called bacillus and often have the term in their name – such as Lactobacillus the bacteria found in milk that makes milk smell sour as their populations grow. The “sphere-shaped” bacteria are called coccus – such as Streptococcus (the bacterium that causes strep throat) and Enterococcus (the fecal bacterium used for monitoring water quality in marine waters). And the third group are “spiral-shaped” and are called spirillum – such as Campylobacter and Helicobacter both are human pathogens.
The rod-shaped bacterium known as bacillus.
Image: Wikipedia.
The bacterium known as coccus.
Image: Loyola University
The bacterium known as spirillum.
Image: Lake Superior College.
Bacteria are very abundant in the marine and estuarine waters of the Gulf of Mexico. They can be found floating in the water column, on the surface of the sediment, beneath the surface of the sediment, and on the bodies of marine organisms. When we think of bacteria we think of “dirty” conditions and disease, but many bacteria provide very important ecological benefits to the marine ecosystem and are “good” members of the community.
One important role some bacteria play is the conversion (“fixing”) of nutrients. Animals release toxic waste when they defecate and urinate. One of these is ammonia. Ammonia can bond with oxygen depleting the body of this needed element. Nitrogen fixing bacteria can convert toxic ammonia released into the environment into nitrite. Then another group of nitrogen fixing bacteria will convert nitrite into nitrate – a needed nutrient for plants, and eventually the entire food chain.
Some bacteria are excellent decomposers. When plants and animals die we say they “decay”. What is actually happening is the decomposing bacteria are converting nutrients in their bodies to forms that are usable by living organisms. One byproduct of this decomposition process is hydrogen sulfide – which smells like rotten eggs. In biologically productive ecosystems – like swamps and marshes – the smell of hydrogen sulfide is strong – often called “swamp gas”. It is the smell of nutrient conversion and much needed. Though in high concentrations, hydrogen sulfide is toxic as well – there needs to be a balance. We see this same process happenings when we compost food waste to form fertilizers for our gardens.
One place where the smell of sulfur is very strong is near volcanic vents. If you have been to Yellowstone, or a volcano, the smell is very evident. There are what are termed “extreme bacteria” who can live in these very hot, almost toxic, environments. Just as plants take water and carbon dioxide and convert this to sugar in the process of photosynthesis, bacteria can convert toxic forms of sulfur into usable carbohydrates for other living organisms. In the 1970s marine scientists discovered thermal vents on the bottom of the ocean. These hot “chimneys” spew black clouds of smoke into the water column. Approaching these chimneys carefully they found water temperatures between 700-800°F! Living close to these chimneys they found communities of worms, shrimps, fish, and crabs. The walls of the chimneys are actually composed of sulfur fixing bacteria that are converting volcanic minerals and compounds into sugars in a process called chemosynthesis – which supports these deep-sea communities.
The black smokers – hydrothermal vents – found on the ocean floor.
Photo: Woodshole Oceanographic Institute.
Of course, there are more familiar forms of bacteria that cause disease. Called pathogens – they can be problems for all marine life and sometimes humans. Fecal bacteria associated with human waste are not toxic in themselves at low concentrations. However, if their numbers increase (due to a sewage spill, etc.) these, and other possible pathogenic human bacteria, can be a human health issue. The Florida Department of Health monitors the fecal bacteria levels weekly at beaches where humans like to swim. High concentrations will require the department to issue health advisories. We know that all sorts of bacteria begin to replicate quickly in warmer conditions. This can be a problem with seafood that is not kept cold enough before serving. There are federal regulations on what temperatures commercially harvested seafood must be kept in order to be served or sold to the public. Federal and state agencies can monitor the temperatures of stored seafood as it moves from the fishing vessel to the table. But they cannot monitor it from your fishing rod to your table – that responsibility will fall on you. Pathogenic bacteria is the primary reason we refrigerate and/or freeze much of our food.
Closed due to bacteria.
Photo: Rick O’Connor
Though bacteria in general have a bad name, many species are not harmful to us and are a major player in the health of our estuarine and marine communities.
by Rick O'Connor | Oct 18, 2024
We are going to begin this series of articles with a “creature” that some do not consider alive – viruses. While studying marine science in college, and my early days as a marine science educator, there was a debate as to whether viruses were actually alive and should be included in a biology course. A quick glance at the textbooks of the time shows they were often omitted – though they were included in my microbiology class. Why were they omitted? Why did some consider them “non-living creatures”?
The coronavirus next to a strand of DNA.
Image: Florida International University.
Well, we always began biology 101 with the characteristics of life. Let’s scan these characteristics and see where viruses fit.
- Made of cells. This is not the case for viruses. A typical cell will include a cell membrane filled with cytoplasm and a nucleus, which is filled with genetic material (chromosomes containing DNA and RNA). An examination of a virus you will find it is either DNA or RNA encapsulated in a protein coat. It is “nucleus-like” in nature. Most cells run between 10-20 microns in size. A typical nucleus within a mammal cell will run between 5-10 microns. A typical virus would be 0.1 microns – these are tiny things – MUCH smaller than a cell.
- Process energy. Nope – they do not. Most cells utilize energy during their metabolism. Viruses do not do this.
- Growth and development. Nope again. They “spread”, which we discuss in a moment, but they do not grow. We are now 0-3.
- Homeostasis. Homeostasis is the movement of material and environmental control to remain stable – and viruses do not do this.
- Respond to stimuli. Yes… here is one they do. Studies show that viruses do respond to their chemical and physical environment.
- Metabolism. As mentioned above, this would be a no.
- Adaptation. Studies show that through very rapid reproduction they can adapt to the changing environment they are in.
- Reproduce. This is a sort of “yes/no” answer. They do reproduce (as we say – “spread”) but they do not do this on their own. They invade the nucleus within the cells of their host and replace their genetic material with that of the host creature. Then, during cell replication within the host, new viruses are produced and “spread”.
So, you can see why there is a debate. Of the eight common characteristics of life, viruses possess only three – and one of those can only be achieved with the assistance of a host creature. Now the question would be – do be labeled as a “creature” do you need ALL eight characteristics of life? Or only a few? And if only a few – how many? Because of this most biologists do not consider them alive.
During one class when we were discussing this a student made a comment – “don’t we KILL viruses? If so, then it must be alive first”. Point taken – and we should understand the phrase “kill a viruses” does not mean literally killing. It is a phrase we use. Though some argue we do kill viruses and thus…
Another point we could make here is that all life on the planet has been classified using a system developed by the Swedish botanist Carlos Linnaeus. Each creature is placed in a kingdom, then phylum, class, order, family, genus, and eventually a species name is given. We “name” the creature using its genus and species name – Homo sapiens for example. We do not see this for viruses.
All that said, both the National Oceanic and Atmospheric Administration and the National Institute of Health indicate the “most common form of life in the sea are viral-like particles” – with over 10 million in a single drop of seawater. We will leave the debate here. Your thoughts?
by Laura Tiu | Sep 13, 2024
Western Dune Lake Tour
Walton County in the Florida Panhandle has 26 miles of coastline dotted with 15 named coastal dune lakes. Coastal dune lakes are technically permanent bodies of water found within 2 miles of the coast. However, the Walton County dune lakes are a unique geographical feature found only in Madagascar, Australia, New Zealand, Oregon, and here in Walton County.
What makes these lakes unique is that they have an intermittent connection with the Gulf of Mexico through an outfall where Gulf water and freshwater flow back and forth depending on rainfall, storm surge and tides. This causes the water salinity of the lakes to vary significantly from fresh to saline depending on which way the water is flowing. This diverse and distinctive environment hosts many plants and animals unique to this habitat.
There are several ways to enjoy our Coastal Dune Lakes for recreation. Activities include stand up paddle boarding, kayaking, or canoeing on the lakes located in State Parks. The lakes are popular birding and fishing spots and some offer nearby hiking trails.
The state park provides kayaks for exploring the dune lake at Topsail. It can be reached by hiking or a tram they provide.
Walton County has a county-led program to protect our coastal dune lakes. The Coastal Dune Lakes Advisory Board meets to discuss the county’s efforts to preserve the lakes and publicize the unique biological systems the lakes provide. Each year they sponsor events during October, Dune Lake Awareness month. This year, the Walton County Extension Office is hosting a Dune Lake Tour on October 17th. Registration will be available on Eventbrite starting September 17th. You can check out the Walton County Extension Facebook page for additional information.
by Laura Tiu | Aug 10, 2024
My son and his girlfriend were visiting last week and wanted to go fishing. Since she had never been deep sea fishing before, we decided that the best course of action would be to take the short four-hour trip on one of Destin’s party boats.
Party boats, also known as a head boat, are typically large boats from 50 to 100 feet long. They can accommodate many anglers and are an economical choice for first-time anglers, small, and large groups. The boat we went on holds up to 60 anglers, has restrooms, and a galley with snacks and drinks, although you can also bring your own. The cost per angler is usually in the $75 – $100 range and trips can last 4, 6, 8, or 10 hours.
We purchased our tickets through the online website and checked in at the booth 30 minutes before we departed. Everyone gets on and finds a spot next to a fishing pole already placed in a holder on the railing. For the four-hour trip, it is about an hour ride out to the reefs. On the way out, the enthusiastic and ever helpful deckhands explain what is going to happen and pass out a solo cup of bait, usually squid and cut mackerel, to each angler. When you get to the reef, you bait your hooks (two per rod) and the captain says, “start fishing.”
The rods are a bit heavy and there are some tricks you need to learn to correctly drop your bait 100 feet to the bottom of the Gulf. The deckhands are nearby to help any beginners and soon everyone is baiting, dropping, and reeling on their own. There are a few hazards like a sharp hook while baiting, crossing with your neighbor’s line and getting tangled, and the worst one, creating a “birds nest” by not correctly dropping your line. Nothing the deckhands can’t help with.
When you do finally catch a fish, you reel it up quickly and into the boat where a deckhand will measure it to make sure it’s a legal species and size and then use a de-hooker to place the fish in your bucket. After about 30 to 40 minutes, the captain will tell everyone to reel up before proceeding to another reef. At this time, you take your fish to the back of the boat where the deckhands put your fish on a numbered stringer and on ice.
For the four-hour trip, we fished two reefs. We had a lucky day with the three of us catching a total of 16 vermillion snapper, the most popular fish caught on Destin party boats. It’s a relaxing ride back to the harbor during which the deckhands pass the bucket to collect any tips. The recommended tip is 15-20% of your ticket price. These folks work hard and exclusively for tips, so if you had a good time, tip generously.
Once back in the harbor, your stringer of fish is placed on a board with everyone’s catch and they take the time for anyone that wants to get some pictures with the catch. Then, you can load your fish into your cooler, or the deckhands will clean your fish for you for another tip. If you get your fish filleted, you can take them to several local restaurants that will cook your catch for you along with some fries, hush puppies and coleslaw. It is an awesome way to end your day.
A happy angler after a party boat excursion.
