by Erik Lovestrand | Feb 2, 2018
Sorting and re-caging take place on-site at the lease
Photo: Erik Lovestrand
There are a number of parallels than can be drawn between shellfish farming and traditional forms of agriculture that take place on the land. The most obvious similarities are the amount of hard work, grit and faith that are required of the farmer on land or sea. In spite of this there are many “salty” farmers in the Florida Panhandle who have mustered the faith requirement and are now putting in the hard work necessary to help build this budding industry in the Southeastern U.S.
Market demand for quality oysters has continued to outstrip available supplies for several years of late. This has been due in part to better marketing strategies employed by growers as well as clientele becoming aware of the health benefits of fresh oysters; a great supply of important vitamins and minerals, including vitamin C and B vitamins, zinc, selenium and iron. However, supply/demand ratios are not the only important factor in developing a thriving oyster aquaculture industry. Also required, is the necessary infrastructure to support the grower’s equipment needs, enough sources of baby oyster “seed”, a reliable refrigerated transportation network for live shellfish, and the support of regulatory agencies in making water leases available in suitable growing areas.
Fortunately, the stars seem to be aligning for many of these industry-growth necessities and the business of oyster farming is gaining a firmer foundation to build upon. One of the important milestones for Florida was the approval of “full-water-column” leases, which allows the use of floating oyster cages or bags. Previously, oysters were required to be grown on the bay bottom and this made them susceptible to higher levels of predation from crabs and snails and severe biofouling (barnacles and algae) on the exterior of the mesh bags. Heavy biofouling reduces the water flow through the oyster’s growing environment, thus the available food for this filter feeding bivalve.
One critical need for this industry is the availability of quality “seed” (baby oysters) to put in the growing waters. Seed oysters are supplied by hatcheries where oyster brood stocks are spawned and babies are raised to the necessary age for grower needs. Some growers use baby oyster larvae that have not settled and attached yet. These “eyed larvae” are put in a tank with old oyster shell and allowed to attach on the shells, which are then deployed at a lease site. Other growers use seed that has already attached to a small particle of crushed shell and are sold as individual oysters to be placed in grow-out bags or cages. The more recent development of oyster stocks with 3 sets of chromosomes (triploids) have provided growers with an oyster that gets to market size faster. Triploid oysters are infertile and do not use energy for spawning, thereby putting more energy into shell and tissue growth. Federal and state laws also govern where growers can buy their seed in an effort aimed at stopping the spread of shellfish disease from one body of water to another (i.e. Atlantic to Gulf of Mexico, etc.).
Even if all of the hardware and infrastructure is in place, there is still one other factor that plays a significant role in whether an oyster farmer will be successful. Just like the dairy farmer, the cattle rancher, the cotton or peanut grower, or the blueberry producer; backbreaking labor is necessary for many stages of the production cycle. Oyster growers work their leases either bending over the gunnels of a boat or actually being in the water, lifting heavy bags or cages of shellfish, sorting by size, re-caging, and moving lots of materials to and from the lease area. True grit and a dogged determination to stay on top of things, regardless of unpleasant conditions, are vital to raising a successful crop of oysters. And by the way, don’t forget that Mother Nature will have the final word. As all farmers know, they are required to be a good listener when she speaks.
by Rick O'Connor | Jan 5, 2018
Last year I began a series of articles on the Gulf of Mexico. They focused on the physical Gulf – water, currents, and the ocean floor. This year the articles will focus on the life within the Gulf, and there is a lot of it.
Single celled algae are the “grasses of the sea” and provide the base of most marine food chains.
Photo: University of New Hampshire
We will begin with the base of food web systems, the simplest creatures in the sea. The base of food systems are generally plants and the simplest of these are the single celled plants. Singled celled plants are a form of algae, not true plants in the sense we think of them, but serving the same role in the environment – which is the production of much needed energy.
What these single celled algae need to survive is the same as the more commonly known plants – sunlight, water, carbon dioxide, oxygen, and nutrients.
Sunlight is difficult for marine plants because sunlight only penetrates so deep. Therefore, marine plants and algae must live in shallow water, or have some mechanism to remain near the surface in the open sea. In relation to their overall body volume, smaller creatures have more surface area than larger ones. More surface area helps resist sinking and the smallest you can get is a single cell. Thus, most marine algae are single celled. Many single celled plants are encased in transparent shells that have spines and other adaptations to assist in increasing their surface area and keeping them near the surface. Some actually have drops of oil (buoyant in water) making it even easier to stay near the surface. These small floating algae drift in the surface currents, and drifting organisms are called plankton. Plankton that are “plant-like” are called phytoplankton.
The next needed resource is water; the Gulf and Bay are full of it. However, saltwater is not what they need – freshwater is, so they must desalinate the water before absorbing it. They can do this by adjusting the solutes within their cytoplasm. The greater the ratio of surface area is to volume, the more diffusion of solutes can take place – thus these small phytoplankton are very good at diffusing resources in (like water and carbon dioxide) and expelling waste (like ammonia and oxygen).
Image showing how deep different colors of light penetrates in the sea.
Image: Minnesota Sea Grant
Carbon dioxide and oxygen are dissolved in seawater and, like water, are diffused into the phytoplankton. Warmer water holds less oxygen so there would be a tendency to have more phytoplankton in colder waters. However, warmer waters are so because there is generally more sunlight, a needed resource. The colder, sunlit, surface waters off some coasts – such as California – have higher amounts of dissolved oxygen and are some of the most productive areas in the ocean. Phytoplankton can also serve as “carbon sinks” by removing carbon dioxide dissolved in the seawater coming from the atmosphere. However, this may not be the answer to excessive CO2 in the atmosphere because, like all creatures, you can only consume so much “food”. Excessive loads of carbon dioxide will not be consumed.
Finally, there is the need for nutrients. All plants need fertilizer. Nutrients in the sea come from either run-off from land, or decayed material from the ocean floor. Much of the nutrients are discharged into the Gulf by run-off from land. Because of this, much of the phytoplankton are congregated nearshore where rivers meet the sea. We think of marine life as equally distributed across the ocean, but in act it is not, there is more life nearshore. For the compost on the ocean floor to be of used by phytoplankton, it must reach the surface. This happens where a current called an upwelling occurs. Upwellings rise from the seafloor bringing with them the nutrients. Where upwellings occur, the seawater is colder, and sunlight abundant, you have the greatest concentration of marine life – all fueled by these phytoplankton.
In the Gulf, one of the most productive places is “the plume”, where the Mississippi River discharges. This massive river brings water, sediments, and nutrients, from most of the continent. The large plankton blooms attract massive schools of plankton consuming fish, predatory fish, sea birds, and marine mammals.
In the next post, we discuss some of the different phytoplankton that inhabit our coastal waters and the amazing things they do.
A satellite image showing the sediment plume of the Mississippi River. This plume brings with it nutrients that fuel plankton blooms.
Image: NASA satellite
References
Kirst G.O. (1996) Osmotic Adjustment in Phytoplankton and MacroAlgae. In: Kiene R.P., Visscher P.T.,
Keller M.D., Kirst G.O. (eds) Biological and Environmental Chemistry of DMSP and Related Sulfonium Compounds. Springer, Boston, MA
by Rick O'Connor | Oct 31, 2017
In our continuing battle with invasive species, northwest Florida is now home to an invasive lizard. Known as both the Cuban and Brown Anole, this animal has been reported from Big Lagoon, East Hill, North Hill, and Gulf Breeze in the Pensacola area. I have seen it at almost every rest area on I-10 between here and Gainesville and in large numbers at some local nurseries.
This Cuban Anole was photographed on a public hiking trail near Perdido Key.
Photo: Jerry Patee
Who is this new invader to our area?
We will start with “new”.
Compared to the rest of the state, it is new. First reported in 1887, this lizard hitchhiked over from its native Cuba and Bahamas via boats. DNA studies suggest there were at least seven different “invasions” of the lizard to Florida. This is not surprising since the lizard is small (between 5-8 inches) and likes moist areas to lay eggs. A fan of warmth, vegetation, and insects – it did very well once it arrived. Like most invasive species, it quickly spreads into disturbed areas… and we have disturbed Florida in a major way. It is now found in all counties within the Florida peninsula and in many, it is the most common lizard seen.
Is it an “invader”?
Yes, in the sense that it moves into disturbed habitats quickly and competes with the native Green Anole (Anole carolinensis). Both lizards are beneficial to humans in that they consume great numbers of insects and spiders. However, the Cuban Anole will consume the eggs and juveniles of the Green Anole. Where the two co-exist, the Green Anole is forced to live higher up in the vegetation. This is a form of resource partitioning where each species is co-existing in the same area but not directly competing. However, biologists are not sure how this co-habitation of the two lizards will affect local ecology. It is currently listed as an invasive species in Florida.
So is it new to the panhandle?
Well, based on records – yes. Based on anecdotal comments – no. Some folks have seen it for some time now. The most probable means for dispersal have been with forms of transportation visiting the panhandle from south Florida and the transport of landscaping plants from south Florida nurseries. One local nursery had a greenhouse over-run with the lizard. If you view the invasive database EDDMaps. It shows 13 records between Alabama and the Aucilla River. There are certainly more than that. EDDMaps has the distribution broken down as:
| County |
Number of Cuban Anole Records |
| Bay |
1 |
| Calhoun |
0 |
| Escambia |
0 |
| Franklin |
0 |
| Gadsden |
0 |
| Gulf |
0 |
| Holmes |
0 |
| Jackson |
1 |
| Jefferson |
0 |
| Leon |
2 |
| Liberty |
0 |
| Okaloosa |
4 |
| Santa Rosa |
4 |
| Wakulla |
0 |
| Walton |
0 |
| Washington |
1 |
Several local residents have sent me photos of the Cuban Anole in Pensacola (used in this article). I will need to post these soon and we will need help from the public posting more. To report anoles, you will need to log into EDDMaps at www.EDDMaps.org. You will need an account, but it is free. You can also download their app “I’ve Got 1”, which can be found on the website. If you have questions about EDDMaps, please contact me at the Escambia County extension office (850) 475-5230.
This Cuban Anole was photographed at the east end of Big Lagoon near NAS Pensacola.
Photo: Carole Tebay
Until then, check your cars before heading back from south Florida and any plants you may buy from nurseries to be sure you are not bringing any friends home. If you are finding them in your yard and wish to control them, contact me at the Escambia County extension office.
References
Anoles. 2017. University of Florida IFAS Gardening Solutions. http://www.gardeningsolutions.ifas.ufl.edu/design/gardening-with-wildlife/anoles.html.
Brown Anole (Anole sageri) Introduced. Savannah River Ecological Laboratory. University of Georgia. http://srelherp.uga.edu/lizards/anosag.htm.
Dunning, S. 2017. The Cuban Anole. NISAW 2017. Panhandle Outdoors Electronic Newsletter. https://nwdistrict.ifas.ufl.edu/nat/2017/02/28/nisaw-2017-cuban-anole/.
EDDMaps. 2017. Distribution Map by County. http://www.eddmaps.org/distribution/uscounty.cfm?sub=18342.
Johnson, S.A. 2011. Focal Species: Cuban Brown Anole. The Invader Updater. Vol 3 (1). http://ufwildlife.ifas.ufl.edu/InvaderUpdater/pdfs/InvaderUpdater_Winter2011.pdf.
Nonnative Species: The Brown Anole. Florida Fish and Wildlife Conservation Commission. http://myfwc.com/wildlifehabitats/nonnatives/reptiles/brown-anole/.
