Kenneth L. Heck, Jr., Ph.D.
Senior Marine Scientist III, Emeritus Faculty
Professor, University of South Alabama
I am a marine ecologist whose research has focused on plant-animal interactions in coastal waters, with an emphasis on seagrass-dominated systems. I have worked primarily on the U.S. Atlantic and Gulf coasts, but have also studied seagrass meadows in Central America, as well as in Europe and Western Australia. Recently, I have also been collaborating with several close colleagues in efforts to restore northern Gulf oyster reefs and seagrass meadows.
My academic training began at the University of West Florida where I received a B. S. in Biology. After a stint in the U.S. Army, I subsequently received an M.S. with Skip Livingston at Florida State University (FSU), and then continued on there to do a PhD with Dan Simberloff. Upon leaving FSU I became an Assistant Curator at the Estuarine Research Laboratory of the Academy of Natural Science in Benedict, Maryland. Four years later I became an Associate Curator and Director of the Patrick Center for Environmental Research at the Academy of Natural Sciences in Philadelphia. In 1986 I accepted positions as Senior Scientist at the Dauphin Island Sea Lab (DISL) and Associate (and later Full) Professor at the University of South Alabama (USA).
During my time at Dauphin Island I have served as Research Director, Chief Scientist, Chair of University Programs, Associate Director of the Alabama Center for Estuarine Studies and Director of the Shelby Center for Ecosystem-Based Fisheries Management. Currently, I a tenured Professor in the Marine Sciences Department at USA. During my years at DISL I have had the good fortune to collaborate with exceptional faculty colleagues, extremely productive post-doctoral scholars and technicians, and an outstanding group of graduate students. I have also mentored more than 50 undergraduate interns who, along with my graduate students, have helped maintain my undiminished enthusiasm for coastal and estuarine science.
During my career I have edited two volumes of scholarly works, co-edited a special issue of the journal Estuaries and published more than 170 peer-reviewed articles. I have held editorial positions at the journals Systematic Zoology, Estuaries and Coasts, and am presently editor of Gulf of Mexico Science and continue as a long-standing Contributing Editor for Marine Ecology Progress Series. I regularly serve on advisory and review panels for state and federal agencies. Recently, I have served on the Scientific Advisory Committee for the Mobile Bay National Estuary Program, on EPA and NOAA panels concerning the establishment of nutrient criteria in Florida waters and the effects of sea level rise on the northern Gulf of Mexico, and on an SAV review panel for the Chesapeake Bay. For the past several years, I served as a consultant to NOAA on the effects of the Deepwater Horizon disaster on Gulf of Mexico seagrass meadows, and served on a National Research Council panel charged with developing monitoring and evaluations protocols for on-going restoration activities in the Gulf of Mexico. I also currently serve as Past-President of the Coastal and Estuarine Research Federation (CERF), a scientific organization of some 1,100 marine and estuarine scientists that publishes the journal Estuaries and Coasts and sponsors a biennial conference.
Ph.D., Ecology, Florida State University
M.S., Biology, Florida State University
B.S., Biology, University of West Florida
The aereal extent of seagrass meadows has declined globally during the last several decades, with major losses of seagrasses reported along the Atlantic and Gulf coasts of the United States. The positive correlation between the area covered by seagrass and the production of valuable finfish and shellfish has led to a large number of studies designed to elucidate the causes of seagrass declines. Worldwide, the destruction and the loss of critical seagrass habitat are being attributed to both natural and human-induced disturbances. In many cases, deteriorating water quality, especially resulting from excessive nutrient inputs and turbid runoff, has been associated with seagrass loss. Reversing seagrass loss in these cases usually requires large scale changes in land use and water treatment.
Seagrass Restoration via Birdstakes
An increasing threat to seagrass is mechanical damage from motor vessel operation in shallow waters. This is a growing problem in most coastal areas as these areas are more frequently used for recreational activities. In Florida, and elsewhere in the Gulf of Mexico, physical damage by motor vessels is one of the most common human impacts to seagrass beds. Motor vessels are implicated in seagrass bed damage in a number of ways, including anchoring, propeller scarring, and large excavations caused by hull groundings. In 1995 it was estimated that 173,000 acres of seagrass beds in Florida were moderately to severely damaged by boat propellers and hull groundings (Sargent et al. 1995). Fortunately, reversing the seagrass loss in many of these cases can be done on a relatively small scale with public education and restoration (Kirsch et al. 2005; Hall et al. 2006).
Cost-effective techniques are needed to facilitate early intervention for the prevention of scar erosion to enhance seagrass restoration. Our fertilization technique utilizes a novel approach by providing nutrients derived from the feces of sea birds which are encouraged to roost on perches installed at the restoration site (Kenworthy et al. 2000, Hall et al. 2006). The bird roosting stakes are constructed of 1 in. PVC pipe with pressure treated 2 x 2 x 8 inch blocks glued to the top of the stakes. The stakes are pressed into the sediment so they are not submerged at high tide. Seabirds, primarily cormorants, terns, pelicans and blue herons, roost on the stakes and defecate nutrient rich feces which act as a passive fertilizer delivery system putting nutrients into the water and sediment surrounding the stakes.
Seagrass Restoration via Seeds
Shoalgrass (Halodule wrightii) is known to produce copious amounts of seeds in the Gulf of Mexico, with estimates as high as 3000 seeds m-2 in some areas (McMillian 1981) with seeds shown to remain viable for as long as 3 years and 10 months (McMillan 1991). This suggests that substantial seed banks may exist and that seeds buried in local sediments remain viable for periods of nearly four years. To date, there is no study of which we are aware that has determined shoalgrass seed reserves in the northern Gulf. However, a recent paper has documented that around 8% of shoalgrass core samples near Bayou La Batre, Alabama contained developing fruits (McGovern and Blankenhorn 2007), thereby providing evidence that sexual reproduction is occurring in local stands of shoalgrass.
The primary goal of the proposed research is to determine whether there is a sufficient seed reservoir for both SAV species that could be harvested with minimal damage to existing meadows, and, if so, whether restoration by seed planting is a locally viable SAV restoration strategy in the northern Gulf of Mexico and Mobile Bay. The proposed work is largely unproven to date, but the critical need to develop alternative restoration techniques, instead of the highly damaging and usually ineffective transplant methods, means that new and innovative approaches to restoration must be developed and tested.
Recovery of seagrass and recolonization after losses are rare, and destruction of seagrass habitat may have long-term consequences for sediment stability and production of economically important finfish and shellfish (Williams and Heck 2001). For this reason, many coastal states with substantial seagrass resources assess the distribution and abundance of seagrass meadows annually.
We are carrying out an annual monitoring program, beginning in summer 2011, using a tiered monitoring approach to survey the seagrass resources in the Mississippi and Florida portions of the Gulf Islands National Seashore. The protocol is based on a hierarchical design in which “Tier I” monitoring includes aerial surveys, phtointerpretation, mapping and ground truthing. “Tier II” includes rapid assessment of the overall abundance and distribution of seagrasses, and “Tier III” includes long-term detailed monitoring at selected locations. Our effort is specifically for Tier II and Tier III work that is conducted during the summer when seagrass biomass reaches its annual maximum. Because Tier II monitoring is focused on seagrass percent cover and species composition, it has added value in providing ground-truthing data for Tier I as it becomes available from state or federal agencies. Tier III data are useful for evaluating the likely factors involved in explaining observed changes in seagrass maximum depth distribution, percent cover or species composition.
Habitat Connectivity of Nearshore Seagrass Beds and Offshore Fishing Grounds
Halting the decline or facilitating the restoration of nearshore habitats will require an improved method of prioritizing where to spend limited time, money, and effort. One problem in
setting priorities, however, is that the concept of nursery habitat has rarely been defined clearly, even in research studies that purport to test it. Most studies of the nursery-role concept have
focused on seagrasses or wetlands and examined the effects of these habitats on one of three factors: the density, survival, or growth of juveniles. Generally, an area has been called a
nursery if a juvenile fish or invertebrate species occurs at higher densities, avoids predation more successfully, or grows faster there than in other habitats. But only a handful of studies have
attempted to determine how many of the juveniles of a species move successfully from putative nursery habitats to adult habitats (e.g., Gillanders et al. 1996, Kraus and Secor 2005). The evidence that supports successful movement of seagrass or wetland-associated juveniles to adult habitats is largely indirect, both because such movement data are difficult to obtain and because
there has been a dearth of communication between benthic ecologists (who study nearshore ecosystems) and fisheries biologists (who monitor adult stocks). The nursery habitats for a species are those that are the most likely to contribute to future populations. This contribution should be a function of both the size and number of individuals added to adult populations, because both of these factors affect survival, growth, and reproductive success in the adult habitats.
There are very few studies on movement patterns of individuals from potential nurseries to adult habitats, and this is a vital missing link in our understanding of nurseries. Movement of individuals is one of the most difficult variables to measure in ecology. Fortunately, vast improvements in technology -- archival data loggers, stable isotopes, genetic markers, and otolith microchemistry -- now enable researchers to track and infer movements.
Using two species of commercial/recreational significance, we will attempt to elucidate habitat connectivity of relevance to Alabama coastal fisheries. Both the gray snapper (Lutjanusgriseus) and the gag grouper (Mycteroperca microlepis) are most commonly found in seagrass meadows as early and late juveniles, while adults of both species are associated with hard substrates such as hard bottoms and coral reefs (Starck and Schroeder 1971; Rutherford et al. 1989, Koening and Coleman 1998b). In addition, the elemental compositions of the otoliths of both species have been studied, and it is known that different populations of both juvenile gray snapper and gag can be identified by the unique chemical signatures in their otoliths (Lara et al. 2003, Hanson et al.2004)
Climate-mediated ichthyofaunal shifts in the northern Gulf of Mexico: implications for estuarine ecology and nearshore fishery production
Recent increases in global temperatures are expected to drive concurrent changes in the composition and ecology of terrestrial and marine communities worldwide. Thererefore, information on the effects of climate change on marine ecosystems has been repeatedly identified as being critical for the proper implementation of adaptive, ecosystem-based management. However, few studies have quantitatively linked effects of climate change with shifts in regional fishery production. Recently, Fodrie et al. (2010, Global Change Biol) quantified changes in fish assemblages within seagrass meadows of the northern GOM between the 1970s and 2000s, and found that several tropical snapper, grouper and parrotfish species have become significantly more abundant over the last 30+ years. For instance, Lutjanus synagris (lane snapper) was entirely absent three decades ago, but is now the 8th most abundant seagrass-associated fish. L. griseus (gray snapper, now 7th most abundant), Mycteroperca microlepis (gag grouper, now 17th most abundant) and Nicholsina usta (emerald parrotfish, now 23rd most abundant) have also greatly increased.
Coastal seagrass meadows are well known to provide critical nursery habitat for many juvenile fishes and crustaceans that ultimately recruit offshore to highly valuable fisheries (Heck et al. 2003, MEPS). Therefore, there is a pressing need to explore how the changes documented by Fodrie et al. (2010) might affect seagrass nursery habitats in the northern GOM, as well as the very large fishery production that is ultimately and inextricably linked to this iconic nearshore habitat. Doing so is a necessary first step that will assist in the wise management of Essential Fish Habitat as climate continues to evolve.
Therefore, we are addressing the following 2 overarching questions: 1) how have climate-related changes affected the contribution of seagrass nurseries to economically valuable adult populations of snappers and groupers, as well as to endemic red drum and spotted sea trout; and 2) how are food webs in seagrass nursery habitats functioning in response to increases in tropical fish species? To answer these questions we are using both observational (population level) and manipulative (food-web level) approaches.
Shoreline Stabilization via Oyster Reef Restoration
Coastal and shoreline habitats like salt marshes, oyster reefs, and seagrass meadows protect coastal lands from waves and storms, provide shelter and food for many marine organisms, and supply food, occupation, and recreation for human societies. Unfortunately, many of these habitats are also among the most degraded and threatened habitats in the world because of their sensitivity to sea level rise, storms, and increased human utilization. Many previous efforts to protect shorelines have involved the introduction of hardened structures, such as seawalls, rocks, or bulkheads to dampen or reflect wave energy. A major concern in implementing bulkheads and seawalls for coastal property protection is that many nearshore habitats are damaged and destroyed because erosive wave energies are reflected back into the water body, instead of absorbed or dampened. Mobile Bay, like many other coastal areas, is highly developed with a large and increasing proportion of the shorelines armored by bulkheads and seawalls.
At last analysis in 1997, over 30% of the bay’s available coastline was armored with over 10-20 acres of intertidal habitat lost, a high percentage in this microtidal bay. A recent study found that historical armoring and marsh-edge losses have already had negative fisheries consequences, and projected further reductions of blue crab harvest if armoring continues. Recently, a growing initiative for sustainable shoreline protection has focused on balancing effective protection and habitat creation by a variety of new methodologies collectively termed “living-shorelines”. Wave-reducing breakwaters are becoming an increasingly common along sheltered coastlines and are proclaimed by many as a more responsible alternative to traditional shoreline armoring; however, their effectiveness or ecological impact is largely untested.
This project is designed to examine the potential benefit of restoration of shallow subtidal oyster reefs on adjacent nearshore habitats located at Point aux Pines and in the vicinity of Alabama Port, by examining whether such habitats will (1) result in fisheries enhancement; and (2) facilitate the maintenance and expansion of other biogenic habitats, by addressing the following four objectives:
- documenting changes in the physical setting of study sites resulting from the addition of oyster reefs.
- quantifying oyster recruitment and adult density in created nearshore reefs.
- quantifying primary and secondary producers within subtidal and intertidal habitats between created oyster reef and shoreline.
- quantifying juvenile and adult fish and mobile invertebrate utilization of created oyster reefs and adjacent habitats.
Oyster Reef Restoration
Oyster production in Mobile Bay is influenced by several physical, chemical, and biological factors including water quality, storms, disease, predation, overharvest, and the occurrence of low oxygen (hypoxia) or no oxygen (anoxia) events in the near-bottom waters. Hypoxic and anoxic events frequently occur within Mobile Bay waters and can have profound impacts on numerous fisheries species.
During these events, the dissolved oxygen in the water column becomes low enough to stress many organisms, and occasionally this results in the mass shoreward movement of fish and mobile invertebrates, locally-termed “Jubilees”. These low oxygen events are equally stressful for many sessile invertebrates, such as oysters, that have no means to escape the poor water quality. This has posed a challenge for many restoration efforts since most attempts have focused on maximizing acreage at the sacrifice of reef height. Recent research has shown that taller oyster reefs (greater vertical relief) have higher oyster recruitment and persist longer than short reefs, especially in areas that experience prolonged periods of low oxygen. However, it was previously unclear how reef height could affect the entire oyster reef community.
The habitat and feeding grounds for many fish and invertebrates provided by oyster reefs are among the many ecosystem services they provide. Recently, restoring reefs for ecosystem benefits has become popular in many coastal systems like Mobile Bay. It is important that future efforts to create or restore oyster reef habitat understand how reef design (i.e. reef height) and reef location can influence not only the success for the oysters, but also the nearby community of fish and invertebrates.
Ecoysystem Services of Oyster Reefs
Oyster reefs provide numerous important ecosystem services that are only now becoming well documented. Through their filtration activities, oysters remove sediments, phytoplankton, and detrital particles, thereby reducing turbidity and improving water quality. Thus, oysters and other suspension-feeding bivalves may counteract impacts of estuarine eutrophication. Through their removal of organic particles in the water column, oysters divert energy to benthic food chains and depress pelagic energy flows that may lead to noxious sea nettles. Oyster reefs also serve as important biogenic habitat for benthic invertebrates as well as fishes and mobile crustaceans. This recognition of oyster reefs as providers of important ecosystem services, rather than merely a commodity to exploit, coupled with the dramatic depletion of oyster reefs in many estuaries of the southeast US has prompted increased efforts to restore and/or enhance oyster reefs in many estuarine systems.
This project investigates and quantifies the potential of oyster reefs to positively change water clarity, benthic primary production and secondary production, and the nursery value of marsh creeks around Dauphin Island and Little Dauphin Island. By employing a Before-After-Control-Impact Paired (BACI-P) design beginning in the Summer of 2004, we have begun to specifically address each point in the overall hypothesis.
- quantify and monitor the abundance of water-column suspended solids, and nutrients imported into and exported out of the marsh creeks,
- quantify and monitor the abundance and productivity of phytoplankton, benthic micro- and macroalgae, and macrobenthos,
- quantify and monitor species number, densities and secondary productivities of infaunal and benthic macrofaunal communities,
- quantify and monitor relative abundances of juvenile and adult fish and mobile invertebrates.
Ultimately, the results of our study will assist in providing the conceptual and empirical basis to make realistic predictions of ecosystem benefits resulting from oyster reef restoration.
Fisheries Oceanography of Coastal Alabama (FOCAL)
The Dauphin Island Sea Lab (DISL) initiated the Fisheries Oceanography of Coastal Alabama (FOCAL) program in November 2006 with the support of the Marine Resources Division (MRD) of the Alabama Department of Conservation and Natural Resources (ADCNR). The goal of FOCAL is to collect fisheries-independent data in support of ongoing DISL fisheries research and ADCNR management goals. Further, data are collected with respect to ecosystem-based fisheries management considerations to include:
- information on the early stages of marine fishes (eggs and larvae) and their zooplankton predators and prey (seasonality, abundance, vertical distribution, across-shelf distribution and assemblage composition);
- physical characterizations of the offshore, coastal and Mobile Bay environments (water column stratification, temperature, salinity, current velocity and direction);
- seasonal-scale information on the benthic habitats and associated macrofauna on the Alabama shelf (abundance, distribution, seasonality and assemblage composition);
A secondary goal includes process studies to:
- test specific hypotheses about biological-physical coupling
- target specific taxa of interest.
Our current FOCAL study involves using red drum early life history indices to evaluate relationships between larval abundance at ingress to estuarine waters and postsettlement juvenile abundance in seagrass meadows of Mississippi Sound.
Diefenderfer, H.L., L.D. McKinney, W.R. Boynton, K.L. Heck, Jr., B.A. Kleiss, D.R. Mishra, H. Greening, A.A. George II, B.A.C. Kraft, and C.L. King. Ten years of Gulf Coast ecosystem restoration projects since the Deepwater Horizon oil spill. PNAS. 119 (38). e2213639119. doi.org/10.1073/pnas.2213639119.
Fodrie, F.J., K. L. Heck, Jr., C. F. T. Andrus, and S. P. Powers. Determinants of the nursery role of seagrass meadows in the sub-tropical Gulf of Mexico: inshore–offshore connectivity for snapper and grouper. Mar Ecol Prog Ser 647:135-147. https://doi.org/10.3354/meps13403.
Heck, Jr., K.L., M. Samsonova, A.G.B. Poore, and G.A. Hyndes. Global Patterns in Seagrass Herbivory: Why, Despite Existing Evidence, There Are Solid Arguments in Favor of Latitudinal Gradients in Seagrass Herbivory. Estuaries and Coasts (2020). https://doi.org/10.1007/s12237-020-00833-x.
Darnell, K.M., B. T. Furman, K. L. Heck, Jr., D. Byron, L. Reynolds, and K. H. Dunton. Seed Reserve Hot Spots for the Sub-Tropical Seagrass Halodule wrightii (Shoal Grass) in the Northern Gulf of Mexico. Estuaries and Coasts (2020). https://doi.org/10.1007/s12237-020-00808-y.
Rodriguez, A. R. and K.L. Heck, Jr. Green turtle herbivory and its effects on the warm, temperate seagrass meadows of St. Joseph Bay, Florida (USA). Vol. 639: 37–51. doi.org/10.3354/meps13285.
Hill, J. M., P. S. Petraitis, and K. L. Heck, Jr. Submergence, nutrient enrichment, and tropical storm impacts on Spartina alterniflora in the microtidal northern Gulf of Mexico. Vol. 644:33-45. doi.org/10.3354/meps13342.
Valentine, J.F. and K. L. Heck, Jr. Herbivory in Seagrass Meadows: an Evolving Paradigm. Estuaries and Coasts (2020). https://doi.org/10.1007/s12237-020-00849-3
Macy, A., S. Sharma, E. Sparks, J. Goff, K. L. Heck, M. W. Johnson, P. Harper, and J. Cebrian. Tropicalization of the barrier islands of the northern Gulf of Mexico: A comparison of herbivory and decomposition rates between smooth cordgrass (Spartina alterniflora) and black mangrove (Avicennia germinans). PLoS ONE 14(1): e0210144. https://doi.org/10.1371/ journal.pone.0210144.
Livernois, M.C., F.J. Fodrie, K.L. Heck, and S. P. Powers. Emergent intraspecific multiple predator effects shape estuarine trophic dynamics across a gradient of habitat complexity. Journal of Experimental Marine Biology and Ecology. 511 (120-128). https://doi.org/10.1016/j.jembe.2018.12.004.
Heck, K.L. . Seagrass Ecosystems: A career-long quest to understand their inner workings. Gulf and Caribbean Research. Vol. 30 (1). doi.org/10.18785/gcr.3001.06.
Marshak, A.R. and K.L. Heck, Jr. . Competitive interactions among juvenile and adult life stages of northern Gulf of Mexico red snapper Lutjanus campechanus and a tropical range-expanding congener. Marine Ecology Progress Series. 622:139-155.
Heck, K. L., J. Cebrian, S. P. Powers, N. Geraldi, R. Plutchak, D. Byron and K. Major. . Ecosystem Services Provided by Shoreline Reefs in the Gulf of Mexico: An Experimental Assessment Using Live Oysters. In Bilkovic, D. M., Mitchell, M. M., La Peyre, M. K. and Toft, J. D. (eds). Living Shorelines: The Science and Management of Nature-Based Coastal Protection. CRC Press/Taylor & Francis Group, Boca Raton, pp. 401- 420
Marco-Mendez, C., C. Wessel, W. Scheffel, L. Ferrero-Vicente, Y. Fernandez-Torquemada, J. Cebrian, K. L. Heck and J. L. Sanchez-Lizaso. . Lack of impact of Posidonia oceanica leaf nutrient enrichment on Sarpa salpa herbivory: Additional evidence for the generalist consumer behavior of this cornerstone Mediterranean herbivore PLoS ONE 11(12): e0168398. doi:10.1371/journal.pone.0168398
Valentine, J. F., K. L. Heck, M. R. Dardeau, and H. Burch. Ecosystem-based Management of Mobile Bay, Alabama. Pp. 71 -92, In: J.W. Day and A. Yanez\-Arancibia (Eds.), Gulf of Mexico Origin, Waters, and Biota. Volume 4 - Ecosystem -Based Management. Texas A & M University Press, College Station, TX. 466 p.
Peterson, B. J., J. F. Valentine and K. L. Heck. The snapper–grunt pump: Habitat modification and facilitation of the associated benthic plant communities by reef-resident fish. Journal of Experimental Marine Biology and Ecology. 441:50-54.
Baggett, L.P., K.L. Heck, Jr., T.A. Frankovich, A.R. Armitage and J.W. Fourqurean. Nutrient enrichment, grazer identity, and their effects on epiphytic algal assemblages: field experiments in subtropical turtlegrass Thalassia testudinum meadows. Mar. Ecol Progr. Ser. 406: 33 -45.
Valentine J. F., K. L.Heck, Jr., D. Blackmon, B. J. Peterson, M. E. Goecker, J. Christian, R. M. Kroutil, M. A. VanderKlift , K. D. Kirsch, and M. Beck. Exploited species impacts on trophic linkages along reef -seagrass interfaces in the Florida Keys. Ecological Applications 18:1501 -1515.
Valentine, J. F., K. L. Heck, Jr., D. Blackmon, M. E. Goecker, J. Christian, R. M. Kroutil, K. D. Kirsch, B. J. Peterson, M. Beck and M. A. Vanderklift. Food web interactions along seagrass -coral reef boundaries: effects of piscivore reductions on cross -habitat energy exchange. Marine Ecology Progress Series. 333: 37-50.
Heck, K. L., J. F. Valentine, J. R. Pennock, G. Chaplin and P. M. Spitzer. How herbivores can mediate the effects of nutrient enrichment on seagrass meadows: unexpected results of a field experiment. Marine Ecology Progress Series 326:145 -156.
Heck, K. L. and J. F. Valentine. Plant-herbivore interactions in seagrass meadows. Journal of Experimental Marine Biology and Ecology 330:420 -436.
Valentine, J. F. and K. L. Heck, Jr. Interaction strength at the coral reef-seagrass interface: has overfishing diminished the importance of seagrass habitat production for coral reef food webs. Coral Reefs 24:209 -213.
Who We Are
The Marine Ecology Lab under Dr. Ken Heck employs a team approach to problem solving, emphasizing field experimentation as the primary means of attacking ecological problems. Our goal is to understand how physio-chemical and biological factors such as competition and predation influence the structure and function of nearshore marine ecosystems. While our emphasis is on population and community ecology, we also work at the interface of community and ecosystems ecology.
We do both basic and applied research, and our efforts range from investigating the role of larval abundance as it influences the adult population size of blue crabs, to evaluating the cascading trophic effects of overharvesting fish predators from coastal systems. While most of our efforts are focused on studying the plants and animals inhabiting seagrass meadows and on the interactions between seagrass meadows and adjacent habitats (coral reefs, marsh, mangroves), we can also be found working in coral and oyster reef habitats.
Dorothy “Dottie” Byron, MS - Lab Manager
Sharon “Cissie” Havard - Senior Technician
Emelia Marshall - Research Technician/Project Manager
Alexandra Rodriguez, MS: 2016 - 2018
Juvenile green sea turtle grazing on seagrass meadows of St. Joseph Bay, Florida
Mary Kennedy, MS: 2014 - 2016
Impacts of wintering redhead ducks on seagrasses of the northern Gulf of Mexico
Anthony Marshak, Ph.D.: 2008 - 2016
Ecological impacts of climate-related ichthyofaunal shifts upon the northern Gulf of Mexico red snapper population and reef fish community
Whitney Scheffel, MS: 2012 - 2015
Black mangrove expansion into salt marshes of the northern Gulf of Mexico: Will climate result in significant ecosystem-level changes?
Rebecca Gericke, MS: 2008-2011
Effects of climate-driven range expansions of tropical snapper species (lutjanus spp.) on the dominant native species (pinfish, Lagodon rhomboides)
Joseph Myers, MS: 2008-2011
Effects of species-specific grazing and nutrient addition on growth and production of the shoalgrass Halodule wrightii and its epiphytes
Karen Fisher, MS: 2008-2011
Evaluating nursery habitat utilization by juvenile gray snapper (Lutjanus griseus) in the northern Gulf of Mexico
Lesley Baggett, PhD: 2003-2010
The effects of nutrient enrichment on the seagrass Thalassia testudinum and the stoichiometry, fitness, fecundity, and feeding preference of its associated epiphyte grazers in Florida Bay, Florida
Robert Gutierrez, MS: 2006- 2009
The effects of increased nutrients via bird guano on seagrass macroinfaunal communities
Kelly McKay Darnell, MS: 2005-2008
The effects of prior grazing by the variegated sea urchin and the bucktooth parrotfish on the palatability of turtlegrass
Carly Steeves Canion, MS: 2005 - 2007
The effect of habitat complexity on predation rate: Re-evaluating the current paradigm in seagrass beds
Matthew Johnson, PhD: 2006
The Role of Habitat Fragmentation on the Structure and Function of Seagrass Ecosystems in the Northern Gulf of Mexico
Dale Booth, MS: 2006
The impacts of the American Oyster (Crassostrea virginia) on growth and recruitment of Halodule wrightii
Bradley Furman, MS: 2006
Effects of nutrient enrichment and herbivore density on macroalgal diversity and abundance in a tropical reef ecosystem using Diadema antillarum as the model herbivore
K. Lindsey Kramer, MS: 2005
Have marine reserves made a difference? Fish community structure, grazing intensity and coral recruitment on protected patch reefs
Margene "Meg" Goecker, MS: 2003
The effects of nitrogen content of turtlegrass, Thalassia testudinum, on rates of herbivory by the bucktooth parrotfish, Sparisoma radians
Deborah Kilbane, MS: 2003
Intra-year class cannibalism in early juvenile blue crabs (Callinectes sapidus)
Stacy Harter, MS: 2002
The effects of predation risk on growth rates of juvenile pinfish (Lagodon rhomboides) in Big Lagoon, Florida
Leslie Gallagher, MS: 2001
An evaluation of potential artifacts associated with caging experiments
Jason Stutes, MS: 2000
The relative importance of vertebrate and invertebrate grazing on epiphytes in a seagrass bed in the Northern Gulf of Mexico: an experimental assessment
Kristen Walker, MS: 1998
Bradley Peterson, PhD: 1998
Interactions between semi-infaunal suspension feeding bivalves (Modiolus americanus) and seagrass assemblages (Thalassia testudinum)
Patricia Spitzer, MS: 1998
The effects of vegetations density on the relative growth rates and foraging behavior of pinfish,Lagodon rhomboides (L.), in Big Lagoon, Florida
Katherine Canter, MS: 1998
Foraging effects of gulf oyster toadfish, Opsanus beta, on juvenile xanthid and portunid crabs during altered habitat complexity and light
Paul Bologna, PhD: 1997
The effects of seagrass habitat architecture on associated fauna
Patric Harper, MS: 1994
Seagrass community regulation: effects of manipulating top predators and dominant macrograzers
Laurie Sullivan, MS: 1994
Ecological studies of the mangrove gastropod Littoraria angulifera (littorinidae): distribution, predation, and algal interactions
Susan Sklenar, MS: 1994
Interactions between sea urchin grazers (Lytechinus variegatus and Arbacia punctulata) and mussels (Modiolus americanus): a mutualistic relationship?
Barbara Randall Gibbs, MS: 1994
Experiments on shelter availability and interactions on juvenile stone crabs, Menippe adina
David Nadeau, MS: 1991
Relative growth rates of predatory fishes in vegetated and unvegetated habitats: field experiments with juvenile red drum, Sciaenops ocellatus
Past REU students
Joshua Hancock: 2012 - Influence of bird presence on relative predation rates of brown shrimp, Farfantepenaeus aztecus, within seagrass beds
Natasha Zarnstroff: 2011 - Ecological effects of restoring seagrass to coastal northern Gulf of Mexico waters
Helen Croce: 2010 - The effect of nutrient enrichment on grazer interactions with Halodule wrightii.
Lauren Grove: (REU) 2007 - The effects of nutrient enrichment on abundance growth fecundity and C:N Ratios of Consumers in Thalassia testudinum.
**Karen Fisher: 2006 - The effects of nutrient enrichment on growth, fecundity and stoichiometry of epiphyte grazers in Thalassia testudinum beds.
Erin Morgan: 2005 - Effects of live-bait shrimp trawling on widgeongrass (Ruppia maritima) beds and bycatch in Grand Bay, National Estuarine Research Reserve.
Abigail Poray: 2003 - The effects of grazing on nitrogen content as an induced defense in turtlegrass, Thalassia testudinum
Lisa Zarubick: 2002 - The effects of nitrogen concentration on herbivory of turtlegrass, Thalassia testudiunum, in the Florida Keys National Marine Sanctuary.
Heather Bracken: 2001- Seagrass Herbivory: The effects of predation risk and nutritional content in the Upper Florida Keys.
**Meg Goecker: 2000 - Seagrass Herbivory: The Effects of Predation Risk and Nutritional Content in the Upper Florida Keys National Marine Sanctuary.
Rachel Mason: 1999 - Effects of the snail Neritina reclivata on the level of epiphytic fouling of wild celery, Vallisneria americana, and its potential impact on growth.
Kelli Milleville: 1998 - The Effect of Predator Density and Refuge on the Rate of Cannibalism in Blue Crabs, Callinectus sapidus
Past Undergraduate Interns
Samantha Linhardt - Fall 2018 - Fall 2019
**Alexandra Rodriguez: Summer - Fall 2015
Brittany Troast: Summer - Fall 2015
Tracey Vlasak: Fall 2015
Olivia Caretti: Summer 2014 - Spring 2015
Madelyn Roycroft: Fall 2014 - Spring 2015
Emily Anderson: Fall 2014
Heidi Herlevi: Fall 2013
Maria Akopyan: Summer - Fall 2013
Micheal Arvin: Summer 2013
**Mary “Maddie” Kennedy: Fall 2012 - Fall 2013
Paul Dixson: Fall 2012
Samantha Swanton: Summer 2012
Ashley Whitt: Fall 2011 - Summer 2012
Kate Walsh: Fall 2011 - Fall 2012
Heather McNair: Summer - Fall 2011
Carrie Harris: Summer 2011
Courtney Chupka: Summer 2011
Nick Tolopka: Spring - Summer 2011
**Whitney Scheffel: Fall 2010 - Summer 2011
Ileana Freytes: Fall 2010
Megan Sabal: Summer 2010 - Summer 2011
Caitlin Bovery: Summer - Fall 2010
Robert Crimian: Summer 2010
Nicole Waite: Summer 2009 - Spring 2010
Michelle Beumer: Summer - Fall 2009
Carrie Robbins: Fall 2009
Ariel Leon: Summer 2009
John Tiggelaar: Fall 2008
Angela Vincent: Fall 2008
Michelle Brodeur: Summer 2008
Carl Wepking: Summer 2008
**Rebecca Gericke: Fall 2007
Cailtin Hamer: Fall 2007
**Joe Myers: Summer 2007
Sara Tappan: Summer 2007
Camilla Gustafsson: Fall 2006
Emily Miller: Fall 2006
Savannah Williams: Fall 2006
Jennifer Blaine: Summer 2006
Erika Millstien: Summer 2006
Dan Begert: Fall 2005
Christina Harris: Fall 2005
Meaghean Finnegan: Summer 2005
Megan Kent: Summer 2005
**Randi Shiplett: Fall 2004 - Spring 2005
Jenn Koeppel: Summer 2004
Karlina Merkens: Summer 2004
Rachel Adams: Fall 2003
Kimberly Young: Fall 2003
**Carly Steeves: Summer 2003
Jessica Ebie: Summer 2003
**Brad Furman: Fall 2002
Shawn McCall: Fall 2002
**Dale Booth: Summer - Fall 2002
Rebecca Kordas: Summer 2002
Amy Willman: Fall 2001
Amanda Spivak: Fall 2001
**K. Lindsey Kramer: Summer 2001
Eric Crandall: Fall 2000
Rachel Eichenlaub: Fall 2000
*Deborah Kilbane: Summer 2000
Marissa Axell: Summer 2000
Nicole McMullen: Summer 2000
Dottie Byron: Fall 1999
Heidie Hornstra: Fall 1999
Meredith Ferdie: Summer 1999
Adrienne Jones: Summer 1999
Kevin Yates: Summer 1999
**Indicates undergraduates that have entered the DISL graduate program
Past Post Docs
Candela Marco-Mendez: 2017 - 2018
Jennifer Hill: 2011 - 2015
Patricia Prado: 2008-2009
Joel Fodrie: 2006- 2008
Per Moksnes: 2001-2002
Cyndi Moncreif: 1994
Mike Judge: 1992-1993
John Valentine: 1989-1991
Loren "Bubba" Coen: 1988-1989
Past Fullbright Scholars
Silvia Ibarra: 2001 (CICESE, Ensenada, Mexico)
Johanna Matilla: 1995-1997 (Abo Akademie, Turku, Finland)