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Coral reef fish are collected from the wild and exhibited in aquaria worldwide. Some of the fish spawn in captivity; however, the eggs are usually neglected. In this study, we collected the eggs spawned naturally in the exhibit tanks, hatched and cultured them indoor in 2000-L fibreglass tanks (initial density = 18 000 egg tank−1). We applied an inorganic fertilization method commonly used in freshwater fish culture in raising these coral reef fish larvae. We maintained inorganic phosphorus concentration at 100 μg P L−1 and inorganic nitrogen at 700 μg N L−1 daily in the fertilized group ( n = 4), while the control tanks ( n = 4) were fed with rotifers (10 ind mL−1). Chlorophyll a at particle sizes of both 0.45-20 μm and >20 μm, as well as NH3-N, NO3-N, and PO4-P concentrations were significantly higher in the fertilized group than the control. Zooplankton in the size groups of 10-50 μm (mainly flagellates) and 50-100 μm (mainly ciliates) were abundant (about 10~60 ind mL−1) during 3-7 days in fertilized tanks. The average larval fish survival rate at 21 day after hatch in fertilized group was consistently higher than the control in two trials. The experiments demonstrated that the inorganic fertilization approach can be successfully adapted for coral reef fish culture in an aquarium to achieve sustainable exhibits. [ABSTRACT FROM AUTHOR]

A major constraint in successful larviculture of groupers has been the small gape of the larvae and hence the requirement for small prey at first feeding. In this study, we examined how maintaining a phosphate concentration of 100 μg P L−1 and an inorganic nitrogen (N) level of 700 μg N L−1 via weekly fertilization with inorganic fertilizers affected phytoplankton, zooplankton and giant grouper larval survival in relation to a control group that was provided with rotifers immediately after larvae hatched. Unicellular algae, zooplankton within the size ranges of 10-50 μm and 50-100 μm and survival of giant grouper larvae were all significantly higher in the fertilized treatment compared with the control. Stomach analysis revealed that ciliates and flagellates were actively consumed by larval fish in the fertilized group, whereas few rotifers were consumed in the control. We conclude that the inorganic fertilization method provides high densities of suitable-sized prey for larval groupers at the onset of exogenous feeding before they are able to consume larger, commercially available rotifers and copepods. [ABSTRACT FROM AUTHOR]

Dumping of approximately two million tonnes of steel slag in a shallow (ca. 40 m), sandy-bottom area in southern Taiwan from 1984 to 1989 has caused major changes of the substrate. After cessation of slag disposal, the demersal fish community in the area was monitored for 9 years (1990–1998). Species richness and the Shannon diversity index at the disposal site and a control site were significantly different, while the number of individuals and the Index of Multivariate Dispersion, as a measure of relative variation, were not. Splitting the data according to three 3-year periods did not reveal significant differences in any of the univariate community metrics. However, multivariate analysis revealed significant temporal differences, dispersion becoming smaller over time. It is concluded that slag disposal created a reef-like habitat and the associated fish fauna had a higher diversity than that seen on the sandy bottom present originally, partly caused by increased habitat complexity and partly by diversion of fishing activities because of potential gear damage. However, in the long run the ecological benefits may not last because the habitat is gradually being covered up again by sand. Copyright 2002 International Council for the Exploration of the Sea. Published by Elsevier Science Ltd. All rights reserved. [ABSTRACT FROM PUBLISHER]