Recovery Of Ecological Functions Research Articles

Biodegradable Material for Oyster Reef Restoration: First-Year Performance and Biogeochemical Considerations in a Coastal Lagoon

Oyster reef restoration efforts increasingly consider not only oyster recruitment, but also the recovery of ecological functions and the prevention of deploying harmful plastics. This study investigated the efficacy of a biodegradable plastic-alternative, BESE-elements®, in supporting oyster reef restoration in east-central Florida (USA) with consideration for how this material also influences biogeochemistry. Four experiments (two laboratory, two field-based) were conducted to evaluate the ability of BESE to serve as a microbial substrate, release nutrients, support oyster recruitment and the development of sediment biogeochemical properties on restored reefs, and degrade under field conditions. The results indicated BESE is as successful as traditional plastic in supporting initial reef development. In the lab, BESE accelerated short-term (10-day) sediment respiration rates 14-fold and released dissolved organic carbon, soluble reactive phosphorus, and nitrate to the surface water (71,156, 1980, and 87% increase, respectively) relative to without BESE, but these effects did not translate into measurable changes in reef sediment nutrient pools under field conditions. BESE lost 7–12% mass in the first year, resulting in a half-life of 4.4–6.7 years. Restoration practitioners should evaluate the biogeochemical properties of biodegradable materials prior to large-scale deployment and consider the fate of the restoration effort once the material degrades.

Approach to the Functional Importance of Acropora cervicornis in Outplanting Sites in the Dominican Republic

Coral restoration has been recognized as an increasingly important tool for coral conservation in recent years. In the Caribbean, the endangered staghorn coral, Acropora cervicornis has been studied for restoration for over two decades with most studies focusing on evaluating simple metrics of success such as colony growth and survivorship in both nurseries and outplanted sites. However, for reef restoration to aid in the recovery of ecological function in outplanted sites, there is a need to measure the functional ecology of the impact of outplanting. Here, we present and identify positive ecological processes and ecological functions (such as increased fish biomass, coral cover, and increased in structural complexity) relative to active reef restoration. In the Southeastern Reefs Marine Sanctuary in the Dominican Republic, we monitored the percentage of benthic cover and fish biomass alongside active reef restoration over the period of 12 months in four zones. Subsequently, we developed multidimensional analyses in conjunction with generalized linear models (GLM) and linear models. Our results show there is a remarkable spatial and temporal differentiation favoring greater ecological function in restored areas. We observed the most noticeable patterns of change in the benthos and coral species composition. We found a positive relationship between amounts of outplanted colonies with the total fish biomass for the three outplanted sites. We highlight that Scarus iseri, a parrotfish critical for grazing maintenance, was the species with the greatest benefit. Our results provide evidence of the functional importance of Acropora cervicornis in coral reef active restoration efforts.

Habitat use, movements and site fidelity of the gray smooth-hound shark ( Mustelus californicus Gill 1863) in a newly restored southern California estuary

It is thought that some elasmobranchs use shallow temperate estuaries during warmer months because these habitats may provide thermal physiological advantages. However, extensive loss and degradation of southern California bays and estuaries has reduced coastal species access to estuarine habitats. While restoration of southern California estuaries has increased over the last two decades, little is known about the recovery of ecological function. Top predators are thought to be important indicators of restoration of ecological function in many ecosystems, including estuarine habitats. In this study, abundance surveys and acoustic telemetry were employed to examine how gray smooth-hound sharks (GSH) use the newly restored Full Tidal Basin (FTB) of Bolsa Chica. GSH were most abundant inside the FTB during the spring and summer, and numbers decreased during the winter. Over 83% of all individuals (n = 336) caught were immature juveniles and were most abundant when water temperatures were between 20 and 22 °C. Sharks fitted with acoustic transmitters ( n = 22) were continuously detected for 6–153 days (August 2008–December 2009). Forays into coastal waters were uncommon until individuals left for the season. GSH selected warmer habitats within the middle FTB; however, they also exhibited diel movements along the basin. GSH were most often found associated with mud and eelgrass at night, presumably for feeding. Since its restoration, population and behavioral data suggest that the FTB may provide juvenile GSH with a suitable seasonal environment for feeding and growth.

In Situ Burning Restores the Ecological Function and Structure of an Oil-Impacted Coastal Marsh

As the use of in situ burning for oil spill remediation in coastal wetlands accelerates, the capacity of this procedure to restore the ecological structure and function of oil-impacted wetlands becomes increasingly important. Thus, our research focused on evaluating the functional and structural recovery of a coastal marsh in South Louisiana to an in situ burn following a Hurricane Katrina-induced oil spill. Permanent sampling plots were set up to monitor marsh recovery in the oiled and burned areas as well as non-oiled and non-burned (reference) marshes. Plots were monitored for species composition, stem density, above- and belowground productivity, marsh resiliency, soil chemistry, soil residual oil, and organic matter decomposition. The burn removed the majority of the oil from the marsh, and structurally the marsh recovered rapidly. Plant biomass and species composition returned to control levels within 9 months; however, species richness remained somewhat lower in the oiled and burned areas compared to the reference areas. Recovery of ecological function was also rapid following the in situ burn. Aboveground and belowground plant productivity recovered within one growing season, and although decomposition rates were initially higher in the oiled areas, over time they became equivalent to those in reference sites. Also, marsh resiliency, i.e., the rate of recovery from our applied disturbances, was not affected by the in situ burn. We conclude that in situ burning is an effective way to remove oil and allow ecosystem recovery in coastal marshes.