As we left the winter months and headed into spring I was expecting a lot of new blooms, new animal tracks, and more live encounters with wildlife… and then the rain began. I do not know if the entire panhandle has been getting what Pensacola has but the rain has been nonstop for over a week now. I track rain days for a water quality project and for the first three months of 2015 the number of days during a month where it rained was between 23-30%. We are about half way through April and so far it has rained 61% of the days. WELL… rain or shine we will make this hike and see what is happening on our barrier island.
The first thing I noticed when I began the trip along the Gulf was this large hole left by a sand castle architect. These can be problematic for some forms of wildlife, including sea turtles, but they can also be a problem for rescue and turtle watch vehicles. Please enjoy the beach and make awesome sand castles, but when you are finished please fill the hole.
The line of seaweed and debris that washes ashore during storms is called the wrack. For the most part it is natural material and provides the nutrients needed for many of the high energy shoreline plants to grow. Many of the beach animals found in the berm and primary dune depend on this wrack as well. Many locals and visitors find this material and eye sore and, at times, producing an unpleasant odor. But this material is an important part of the beach ecology. Sargassum is a drifting member of the brown algae, sometimes called “gulfweed”. It possess small air bladder structures called pneumatocysts that allow it to remain at the surface of the open Gulf where the sunlight is. These large offshore mats of Sargassum have been targets for local fishermen for decades. Many small invertebrates live in these drifting mats and these are targets for small fish, which in turn are targets for even larger sport fish. They are also the hideaway for sea turtle hatchlings. When the little guys head for the Gulf after hatching this is where they are heading. Large ocean currents, including the Gulf Stream, push Sargassum into large mats in the middle of the open ocean. The area within the Atlantic where this happens in known as the Sargasso Sea. If you get a chance this summer, grab a small hand net and mask when the Sargassum is just offshore. Collecting you may find a lot of cool interesting creatures. Sea Beans is a generic word for a variety of tropical seeds that wash ashore in the northern Gulf. Some of these may sprout, including mangroves, but most will not make it through our winters.
One of the more venomous jellyfish in Florida waters is now making its way onto our shores. The Portuguese man-of-war, named for the many “guns” this animal possess, is well known by locals but not so much by some of our visitors. The man-of-war is actually not one animal but a colony of sedentary polyp jellyfish that produce an inflated bag which floats at the surface carrying them across the sea. The dark blue tentacles hang down into the water column where passing fish are stung and consumed. Each of the polyps have connecting stomachs which helps move the food around to the whole colony. The sting of this jellyfish is quite painful and should be avoided. When they arrive life guards will usually fly a purple flag.
Their close cousins, the Blue Button Jelly, is very similar to the man-of-war albeit they are much smaller and the venom is not as potent. They are more tropical and not common along the northern Gulf but in recent years more have been washing ashore; they are here now.
One of the bigger issues are oceans are facing are discarded plastics. These materials takes years to decompose and are found in all oceans and seas. Even some distant isolated islands have huge piles of this form of marine debris. Plastics can entangle marine organisms or they may actually swallow it, plugging their digestive system and eventually starving them. We encourage locals and visitors alike to help with this problem by taking your trash with you and discarding it in a location where it will not reach the Gulf.
With the heavy rains of the last week ephemeral ponds have formed on parts of the island. These small pockets of freshwater can be “manna from heaven” for many island residents, particularly the amphibians. I have been hiking this section of Pensacola beach for years, leading field trips for all sorts of groups. I have never seen this Chinese Tallow until today. Also known as the “popcorn tree” due to its unique looking fruit, this plant is listed as an invasive in the state of Florida and is very aggressive. I did not see any others and will seek permission to remove it before it spreads to other dunes and out competes the native plants.
I was actually expecting more flowers to be in bloom this month but there were few. The Conradina, which have been in bloom since February, have lost most of its blossoms. The “new kids on the block” are the Spiderwort, the Primrose, the Sandhill Milkweed, and the Devil’s Joint Cactus.
The Sandhill Milkweed is one of the plants used by the monarch butterfly to gain fuel for their great flight across the Gulf to Mexico. The milky toxic sap of this plant is consumed by the monarch caterpillar but it does not harm it. The chemical toxins therefore become a defense for the monarch and the butterfly has earned the respect of many birds; though it may be a trial and error learning experience.
Most environmental centers, state and federal parks, leave fallen trees where they lie. The tree is actually a storage house of nutrients and full of cavities that can be used by a lot of organisms within the beach community.
This month the weather was warm enough for me to venture into the Salt Marsh. Salt marshes are wetlands but differ from swamps in that the dominate plants are grasses, not trees. Our local salt marsh is dominated by two species of grass, the Smooth Cordgrass, and the Black Needlerush. There are many other plants that exist here but these are the most common. This particular marsh is dominated by Black Needlerush. Salt marshes are one of the most productive systems on the planet, producing tons of organic material annually. 90% of the commercially valuable marine species spend part or all of their lives here. There are many unique species to this system as well. Today the water was crystal clear but I saw few fish. I expect as it gets warmer we will see more. It is very possible that with the heavy rains that they have moved to deeper, saltier spots in the Sound.
The Marsh Periwinkle is an interesting guy. This snail will crawl up the stalks of marsh plants during high tide to avoid predators like blue crab and diamondback terrapins. Both of these predators appear to be on the decline and it will be interesting to see how this impacts the ecology of the marsh. At low tide the periwinkles descend and feed on the organic leaf litter on the muddy bottom.
Though it has a white appearance, Gracilaria is a member of the red algae group. This algae grows on seagrasses as Spanish moss grows on oaks. The plant is usually kept in check by herbivorous grazers, such as green sea turtles, but in recent decades the number of predators have declined and the amount of nutrient runoff has increased. This has sparked a increase in the growth of this algae and, in some cases, to the determent of the seagrass itself.
These photos of peat and the eroded tree are indications of a changing shoreline. Due to storms, boat wake, and time, the shoreline of Santa Rosa Island, like all barrier islands, is changing. Peat is actually the remnants of an old salt marsh that has now pass the high tide line and is within the Sound.
As the weather has warmed and spring break has fallen upon us I have noticed an increase in the amount of trash on this hike, both the Gulf of Sound sides. We encourage locals to take their trash with them and encourage visitors to do the same. Let’s try to keep our waste out of our waters.
I am expecting some animal nesting in May. We will see what we find. Until then.