2 resultados para SCLERACTINIA
em Aquatic Commons
Resumo:
Recruitment, defined and measured as the incorporation of new individuals (i.e. coral juveniles) into a population, is a fundamental process for ecologists, evolutionists and conservationists due to its direct effect on population structure and function. Because most coral populations are self-feeding, a breakdown in recruitment would lead to local extinction. Recruitment indirectly affects both renewal and maintenance of existing and future coral communities, coral reef biodiversity (bottom-up effect) and therefore coral reef resilience. This process has been used as an indirect measure of individual reproductive success (fitness) and is the final stage of larval dispersal leading to population connectivity. As a result, recruitment has been proposed as an indicator of coral-reef health in marine protected areas, as well as a central aspect of the decision-making process concerning management and conservation. The creation of management plans to promote impact mitigation,rehabilitation and conservation of the Colombian coral reefs is a necessity that requires firstly, a review and integration of existing literature on scleractinian coral recruitment in Colombia and secondly, larger scale field studies. This motivated us to summarize and analyze all existing information on coral recruitment to determine the state of knowledge, isolate patterns, identify gaps, and suggest future lines of research.
Resumo:
This document presents the results of the first three monitoring events to track the recovery of a repaired coral reef injured by the M/V Elpis vessel grounding incident of November 11, 1989. This grounding occurred within the boundaries of what at the time was designated the Key Largo National Marine Sanctuary (NMS), now designated the Key Largo NMS Existing Management Area within the Florida Keys National Marine Sanctuary (FKNMS). Pursuant to the National Marine Sanctuaries Act (NMSA) 16 U.S.C. 1431 et seq., and the Florida Keys National Marine Sanctuary and Protection Act (FKNMSPA) of 1990, NOAA is the federal trustee for the natural and cultural resources of the FKNMS. Under Section 312 of the NMSA, NOAA has the authority to recover monetary damages for injury, destruction, or loss of Sanctuary resources, and to use the recovered monies to restore injured or lost sanctuary resources within the FKNMS. The restoration monitoring program tracks patterns of biological recovery, determines the success of restoration measures, and assesses the resiliency to environmental and anthropogenic disturbances of the site over time. To evaluate restoration success, reference habitats adjacent to the restoration site are concurrently monitored to compare the condition of restored reef areas with natural coral reef areas unimpacted by the vessel grounding. Restoration of the site was completed September 1995, and thus far three monitoring events have occurred; one in the summer of 2004, one in the summer of 2005, and the latest in the summer of 2007. The monitoring in 2004 was in the nature of a “pilot project,” or proof of concept. Only the quantitative results of the 2005 and 2007 monitoring are presented and discussed. Monitoring has consisted of assessment of the structural stability of limestone boulders used in the restoration and comparison of the coral communities on the boulders and reference areas. Corals are divided into Gorgonians, Milleporans, and Scleractinians. Coral densities at the Restored and Reference areas for the 2005 and 2007 events are compared, and it is shown that the densities of all taxa in the Restored area are greater by 2007, though not significantly so. For the Scleractinians, number and percentage of colonies by species, as well as several common biodiversity indices are provided. The greater biodiversity of the Restored area is evidenced. Also, size-class frequency distributions for Agaricia spp. (Scleractinia) are presented. These demonstrate the approaching convergence of the Restored and Reference areas in this regard. An inter-annual comparison of densities, within both areas, for all three Orders, is presented. The most noteworthy finding was the relative consistency across time for all taxa in each area. Finally, certain anomalies regarding species settlement patterns are presented. (PDF contains 48 pages.)