Date of Award
Master of Science (MS)
Ocean Engineering and Marine Sciences
The Indian River Lagoon (IRL) is one of the most biologically diverse estuaries in North America. An increase in population and anthropogenic effects have led to eutrophication, a decline in water quality, and overall degradation. The Living Docks program is a citizen science initiative started at the Florida Institute of Technology for lagoon restoration. In this program, public and private docks are volunteered to become Living Docks, where oyster mats made of plastic mesh and dead, dried oyster shells are attached to dock pilings in an effort to provide a natural substrate for benthic organism growth. The community which develops on the oyster mats boosts water filtration to improve overall water quality and combat anthropogenic effects on the lagoon. The purpose of this thesis was to address two questions related to Living Docks: How do abiotic parameters influence the settlement and recruitment of benthic organisms? And what is the filtration capacity of an established Living Dock? These two questions were addressed in a multipart thesis which would assist to further the lagoon restoration efforts of the Living Docks. The first part of this thesis modeled the benthic settlement and recruitment of prominent organisms on the Living Dock oyster mats at four research sites with specific environmental factors (e.g., temperature, salinity, turbidity, and pH). The recruitment and settlement communities were initially the same but diverged over the six-month study period. Beta regression models for benthic recruitment and settlement were created for five of the more dominant organisms observed on the oyster mats- oyster, barnacle, sponge, tubeworm, and encrusting bryozoan. The results of the modeling indicated that benthic settlement and recruitment were driven by different water quality parameters. The settlement was influenced by pH, salinity, dock location, and turbidity. The recruitment was influenced by pH, salinity, dock location, and immersion time. The continuation of monitoring of the water quality surrounding the Living Docks will determine how the benthic community changes over longer periods of time. The second part of this thesis focused on quantifying the filtration capabilities of the same dominant organisms growing on the Living Docks oyster mats at the four research sites described above. The filtration rates were calculated using literature-known values. Encrusting bryozoans contributed the most to the total filtration rate at each of the docks. The IAP dock had the highest abundance of bryozoans and thus had the total highest estimated filtration at 10,108.71 L/hr. The filtration rates for the remainder of the docks, from highest to lowest, were as follows: Anchorage (4,570.34 L/hr), Beachwoods (3,342.66 L/hr), and the Manatee Center (2094.61 L/hr). Care should be taken when interpreting these values because they were based on literature values, and filtration rates can vary greatly in nature with changes in environmental conditions, food concentration, particle size, etc. The results demonstrate the importance of benthic organisms, other than oysters, in significantly contributing to water filtration and ecological services. These estimations and models of the benthic growth on the Living Dock mats quantify the success of the program and can be utilized to advance the outreach of the Living Docks amongst the IRL community.
Rech, Sandra Lisette, "Modeling Settlement and Filtration of the Indian River Lagoon Benthic Community, with an Emphasis on Living Dock Restoration Mats" (2022). Theses and Dissertations. 1222.