(1) conduct synoptic surveys of the IRL to assess clam populations, including historic clam communities and past survey areas (focusing especially on northern and central IRL between Titusville and Sebastian, and the Banana River)
(2) collect broodstock of the targeted taxa and potentially other species if determined beneficial to the restoration objectives. Approximately 100 individuals from each species (including hard and sunray venus clams) will be collected and transported back to the laboratory and/or spawning facilities for spawning and experimentation.
(3) experimentally determine physiological tolerance of the selected bivalve species to key environmental stressors (e.g., salinity, hypoxia, calcium carbonate saturation) and directly measure filtration/ clearance rates via feeding assays of target species. The IRL clams will be compared with similar specimens collected from healthy northeast Florida populations and aquaculture stock for these ex situ trials;
(4) Identify specific genetic markers for stress tolerance using forward next generation transcriptome sequencing and compare stress-induced gene expression of IRL specimens with that of wild (north Florida) and aquaculture populations. Genetic markers that show differences against other bivalves will be used for selection assays to generate stable resilient family lines.
(5) Spawn the collected taxa and rear larvae to field transplant size (‘seed’) at the Whitney Laboratory’s research shellfish hatchery and land-based nursery and commercial partner facilities (Research Aquaculture Inc) for the purpose of repatriating the targeted clams to the IRL and hastening system recovery;
(6) Conduct outplanting of hatchery-reared clams in bags or under cover netting to strategic locations in the IRL (based upon historical sites and current water quality trends) including existing partner habitat restoration and commercial lease areas, and fate-track survivorship and growth.
Outputs
[1] Establishment of brood stock that will serve as the optimized variety (phenotype) lines that will be maintained in two aquaculture facilities (Whitney Lab and Research Aquaculture) for this and future projects.
[2] Repatriation of 1 - 2 million clams reared in both aquaculture facilities to areas of restoration.
[3] A final report that summarizes the findings of the genetic comparisons between clams that survived the IRL blooms and other clams of the same species, but occurring outside the bloom impact footprint. Results of stress resistance testing, filtration rates, and survivorship of phenotypes and summary interpretation will be included in the report.
Short Term Outcomes
This project will initiate activities that are directly aimed at supporting shellfish restoration, which is a valuable IRL management tool waiting to be used. By targeting resistant genotypes for restoration, identifying physiological tolerances, and repatriating these clam varieties in large numbers, we should dramatically increase restoration success. The timeline for this outcome is 1 yr.
Mid Term Outcomes
Positive linkage of genotypes and stress resistance will inform a significant effort to repatriate these shellfish to the IRL and ultimately support the effort to restore healthy seagrasses. The outcome of this work will be to legitimize and prove efficacy of the approach as well as, provide manager and decision makers with the science to back implementation and expenditures in this effort. The time frame for this outcome is 2-3 yrs, and although this is a 1 year effort, we commit to continuing to fate track the out-planted stocks over this critical time period.
Long Term Outcomes
We anticipate this work will form the foundation for restoring shellfish populations in the IRL. The impacts are far-reaching and include improvements to the reliability and feasibility of utilizing filter-feeders to restore water quality, and to reestablish clam populations for future recreational, or even commercial harvesting of wild clams. The benefits are not limited to aquaculture by any means. This work may set the stage for utilizing shellfish population enhancement methods to restore water quality in impaired waters and facilitate the recovery of seagrass habitat (a scenario that has not yet been realized in Florida). Aiding native shellfish populations to overcome hurdles such as low reproductive success caused by diminished brood stock and reduced ability for synchronous spawning can have significant positive effects on ecosystem health due to increased water filtration and nutrient retention. Perhaps most importantly, we foresee a tremendous benefit to the local economy of the five counties that border the IRL by increased recreational activities that will stem from a healthier lagoon. Expected timeline for these outcomes is 3-5yrs.