Coral Recruitment and Regeneration on a Maldivian Reef 21 Months after the Coral Bleaching Event of 1998     

Karen Loch  Wolfgang Loch  Helmut Schuhmacher  Wolf R. See 《Marine Ecology》2002,23(3):219-236

Abstract. This paper describes the quantitative inventory of stony corals on a Maldivian reef after the bleaching event of 1998. The detailed data, collected in March 1999 and March 2000, comprise survival, new recruitment and regenerates. They were obtained in 6 transects laid out randomly on the reef flat, on 22 Acropora tables on 6 sites at the reef edge and on 39 Porites lobata blocks and 1 Diploastrea heliopora colony. The present cover of living zooxanthellate corals is reduced to ca. 2 – 5 % of its previous state. Acroporidae and Pocilloporidae were practically wiped out, while Poritidae survived partly and Agariciidae (esp. Pavona) are now the dominant group. New settlements on dead Acropora tables were mainly Agariciidae, followed by Acroporidae and Pocilloporidae. Regenerates on Porites were pronounced and the apparent yearly increase in mass was about threefold that of Diploastrea, which is 3 – 4 mm per year. The influence on reef ecology in terms of coral substrate and species, possible sources of larvae, change of guilds in reef builders, other species and the prospect for further development of the reef, with respect to growth versus erosion, is discussed.  相似文献   

Korallenriffe—Bedrohungen,Schutzkonzepte und Rehabilitationsmaßnahmen     

Schuhmacher  Helmut 《Ocean Dynamics》1999,51(10):17-23

Ocean Dynamics - Korallenriffe sind der artenreichste Lebensraum im Meer und zugleich der wirkungsvollste Schutz tropischer Küsten. Die hermatypischen Organismen konvertieren durch die...  相似文献   

Mass Diving Tourism – A New Dimension Calls for New Management Approaches     

Peter van Treeck  Helmut Schuhmacher 《Marine pollution bulletin》1999,37(8-12):499-504

Diving has become a booming branch of the tourism business. The economies of many countries with reef-lined coasts depend on high numbers of tourist divers; the resultant degradation of reefs by mechanical damage is accepted due to the short-term gain from the tourism business. Many activities of recreational diving do not particularly require coral reefs – any varied three-dimensional structure (e.g. a wreck) may be sufficiently attractive. The conflict between the needs of nature conservation and the economic interests of diving tourism can be mitigated by the formation of artificial underwater attractions as reef substitutes. Based on experiments in the northern Red Sea, we propose to deposit calcium minerals from the seawater in situ by electrolysis on a template of any desired shape. After transplantation of living coral fragments, a diverse community will develop. With this method different modules can be designed and formed on the seabed which can serve different needs such as diver training, environmental education and recreation as well as reef rehabilitation. By a combination of such modules, a recreational underwater park can be formed well suited to function as a DAD (diver aggregation device) and therefore, divert diver pressure from the natural reef.  相似文献   

Coral Recruitment and Regeneration on a Maldivian Reef Four Years after the Coral Bleaching Event of 1998. Part 2: 2001–2002     

Karen Loch  Wolfgang Loch  Helmut Schuhmacher  & Wolf R. See 《Marine Ecology》2004,25(2):145-154

Abstract.  This paper is the follow-up study to a quantitative inventory of stony corals on a Maldivian reef after the bleaching event of 1998 [Loch, K., W. Loch, H. Schuhmacher & W. R. See, 2002; P.S.Z.N.: Marine Ecology, 23 (3): 219–236] covering the years 2001 and 2002, thereby extending the observation period from 1999 to 2002. Data collection was performed as previously in transects on the reef flat, Acropora tables at the reef rim, Porites lobata blocks and one Diploastrea heliopora colony. While between 2000 and 2001 the transects showed a noticeable increase of living scleractinian colonies of 6.1 per m² of reef surface per year, this had slowed to 0.7 per m² per year by 2002. Likewise, the colonisation of dead Acropora tables had changed from a yearly increase of 14.4 colonies per m² of table surface between 2000 and 2001 to a decrease of 9.4 between 2001 and 2002. The main constituent of the regeneration in transects as well as on Acropora tables was Pavona (Agariciidae), whereas Pocilloporidae and Acroporidae were almost completely missing. A new immigrant was Tubastraea micranthus . Continuous growth of regenerates on Porites presented a columnar form, and the growth rate of D. heliopora was reduced between 2001 and 2002. The influence on reef ecology in terms of coral substrate, species differentiation, growth rate changes, interaction with other organisms and the overall prospect of the reef development on a longer timescale is outlined.  相似文献   

Influence of UV-B Radiation and Temperature on Photodegradation of PAHs: Preliminary Results   总被引：2，自引：0，他引：2  

Martí Nadal  Jason J. Wargent  Kevin C. Jones  Nigel D. Paul  Marta Schuhmacher  José L. Domingo 《Journal of Atmospheric Chemistry》2006,55(3):241-252

The joint impact of UV-B radiation and temperature on photodegradation of polycyclic aromatic hydrocarbons (PAHs) sorbed to an organic solvent was assessed in this study. This approach was experimentally performed in a laboratory investigation by means of comparison of two different environments: Atlantic (Lancaster, UK) and Mediterranean (Tarragona, Catalonia, Spain) climatic conditions. The concentration of 10 PAHs contained in a tetradecane solution was compared under two different temperatures (10 and 20°C) and UV-B doses (6.5 and 22.5 kJ m⁻² day⁻¹). No photodegradation was observed for the heaviest hydrocarbons (benzo(a)anthracene, chrysene, benzo(a)pyrene, dibenzo(g,h,i)perylene and coronene). In general terms, the half-life of PAHs was highly dependent on their molecular weight. Significant faster photodegradation rates were detected specially for light PAHs. It indicates that a synergistic effect occurred when both temperature and UV-B dose increased. This synergism might have a great implication on the long-range transport of environmental organic pollutants taking into account that low-latitude areas are the hottest and most irradiated of the planet.  相似文献   

The Depth Limits of Red Sea Stony Corals: An Ecophysiological Problem (A Deep Diving Survey by Submersible)   总被引：2，自引：0，他引：2  

Hans W.  Fricke Helmut  Schuhmacher 《Marine Ecology》1983,4(2):163-194

Abstract. Along the Sinai coast of the Red Sea a deep diving survey with the research submersible GEO investigated the depth distribution of stony corals. 47 hermatypic species were identified below 50 m; 9 species extended below 100 m. Their depth distributions are related to light penetration. Observed changes in hermatype growth forms with depth were investigated and interpreted as photo-adaptations. 10 species of ahermatypic corals were found between 100–205 m. Ahermatype growth forms are adaptations to plankton feeding and do not change with depth.  相似文献   

The Bryozoan Rhynchozoon larreyi (Audouin, 1826)–A Successful Competitor in Coral Reef Communities of the Red Sea     

Heinrich  Ristedt Helmut  Schuhmacher 《Marine Ecology》1985,6(2):167-179

Abstract. Rhynchozoon larreyi (A udouin , 1826) is a successful competitor for space in sessile reef communities at Port Sudan and Eilat (Red Sea). At these localities it has always been found in association with Zanclea sp. The relationship between the two species is regarded as mutualistic. The hydroid benefits through association with a successful spatial competitor; the bryozoan gains advantage through protection of its surface from predation and fouling. Morphological modification of the bryozoan colony in response to this association leads to a highly organized reticulate surface pattern, which provides both symbionts with access to feeding currents.  相似文献