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991.
992.
In order to develop and test a low-cost method of coral reef rehabilitation, the staghorn corals Acropora muricata and A. vaughani were transplanted to a shallow site with unstable substrate. To avoid abrasion, dislodgement and transport due to water movement, the transplanted corals were tied to string sections, which were connected at the seabed to form a grid. This created stability and improved the survival of the corals. The average increase in weight of live coral over 1 year was 56%, eight times more than the control treatment with unattached coral branches. This difference was mainly due to a reduced partial mortality among smaller coral fragments in the stabilized treatment. Survival was positively related to initial size among the loosely placed coral branches, whereas the attached treatment showed a negative relation between size and relative increase in weight of the surviving parts of the coral branches. Coral fragments were not significantly affected by severe physical damage simulating the effects of handling. 相似文献
993.
Katie T. Sievers Eva C. McClure Rene A. Abesamis Garry R. Russ 《Ecology and evolution》2020,10(24):13673
Nonreef habitats such as mangroves, seagrass, and macroalgal beds are important for foraging, spawning, and as nursery habitat for some coral reef fishes. The spatial configuration of nonreef habitats adjacent to coral reefs can therefore have a substantial influence on the distribution and composition of reef fish. We investigate how different habitats in a tropical seascape in the Philippines influence the presence, density, and biomass of coral reef fishes to understand the relative importance of different habitats across various spatial scales. A detailed seascape map generated from satellite imagery was combined with field surveys of fish and benthic habitat on coral reefs. We then compared the relative importance of local reef (within coral reef) and adjacent habitat (habitats in the surrounding seascape) variables for coral reef fishes. Overall, adjacent habitat variables were as important as local reef variables in explaining reef fish density and biomass, despite being fewer in number in final models. For adult and juvenile wrasses (Labridae), and juveniles of some parrotfish taxa (Chlorurus), adjacent habitat was more important in explaining fish density and biomass. Notably, wrasses were positively influenced by the amount of sand and macroalgae in the adjacent seascape. Adjacent habitat metrics with the highest relative importance were sand (positive), macroalgae (positive), and mangrove habitats (negative), and fish responses to these metrics were consistent across fish groups evaluated. The 500‐m spatial scale was selected most often in models for seascape variables. Local coral reef variables with the greatest importance were percent cover of live coral (positive), sand (negative), and macroalgae (mixed). Incorporating spatial metrics that describe the surrounding seascape will capture more holistic patterns of fish–habitat relationships on reefs. This is important in regions where protection of reef fish habitat is an integral part of fisheries management but where protection of nonreef habitats is often overlooked. 相似文献
994.
Bret S. Danilowicz 《Environmental Biology of Fishes》1997,50(3):257-265
The adults of many coral reef fish species are site-attached, and their habitat is selected at the time of settlement by their
larvae. The length of the planktonic larval period varies both intra- and interspecifically, and it is unknown how the age
and size of larvae may affect their selection of habitat. To investigate the influence of age and size on habitat selection,
I collected newly settled Hawaiian domino damselfish, Dascyllus albisella, daily from grids containing three coral species
at four locations in Kaneohe Bay, Oahu, Hawaii. I recorded the coral species each fish was collected on, and measured and
aged (by otoliths) the collected fish. The results indicate that the coral Pocillopora meandrina was selected by settling
fish significantly more than the other two coral species. Younger and smaller larvae selected this coral species more frequently
than older/larger larvae. In addition, younger/smaller individuals were found more commonly inside the bay than older/larger
settling larvae. Differences in the choice of coral species and location of settlement may be partly due to ontogenetic differences
in the sensory capacities of larvae to detect corals, conspecifics, and predators, or to a larval competency period.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
995.
Diurnal temporal patterns of the diversity and the abundance of reef fishes in a branching coral patch in New Caledonia 下载免费PDF全文
Delphine Mallet Laurent Vigliola Laurent Wantiez Dominique Pelletier 《Austral ecology》2016,41(7):733-744
Small‐scale spatial and temporal variability in animal abundance is an intrinsic characteristic of marine ecosystems but remains largely unknown for most animals, including coral reef fishes. In this study, we used a remote autonomous unbaited video system and recorded reef fish assemblages during daylight hours, 10 times a day for 34 consecutive days in a branching coral patch of the lagoon of New Caledonia. In total, 50 031 fish observations belonging to 114 taxa, 66 genera and 31 families were recorded in 256 recorded videos. Carnivores and herbivore‐detritus feeders dominated the trophic structure. We found significant variations in the composition of fish assemblages between times of day. Taxa richness and fish abundance were greater in the early morning and in the late afternoon than during the day. Fourteen taxa displayed well‐defined temporal patterns in abundance with one taxon influenced by time of day, six influenced by tidal state and seven influenced by both time of day and tidal state. None of these 14 taxa were piscivores, 10 were herbivore‐detritus feeders, three were carnivores and one was plankton feeder. Our results suggest a diel migration from feeding grounds to shelter areas and highlight the importance of taking into account small‐scale temporal variability in animal diversity and abundance when studying connectivity between habitats and monitoring communities. 相似文献
996.
Rapid phase-shift reversal on a Jamaican coral reef 总被引:5,自引:0,他引:5
Joshua A. Idjadi Sarah C. Lee John F. Bruno William F. Precht Laurie Allen-Requa Peter J. Edmunds 《Coral reefs (Online)》2006,25(2):209-211
Many Caribbean reefs have experienced a phase-shift in community structure, the principle features being a decline in coral cover and an increase in macroalgal biomass. However, one Jamaican reef—Dairy Bull on the north shore near Discovery Bay—is once again dominated by scleractinian corals and several key species have returned. Living coral cover at 6–8 m depth at Dairy Bull has doubled over the past 9 years and is now ~54%. The absolute cover of Acropora cervicornis was <1% in 1995, but increased to ~11% by January 2004. During this time the cover of macroalgae decreased by 90%, from 45 to 6%. We speculate that long-lived colonies of Montastraea annularis may have facilitated the recovery of this reef by providing structural refugia. 相似文献
997.
The global degradation of coral reefs is having profound effects on the structure and species richness of associated reef
fish assemblages. Historically, variation in the composition of fish communities has largely been attributed to factors affecting
settlement of reef fish larvae. However, the mechanisms that determine how fish settlers respond to different stages of coral
stress and the extent of coral loss on fish settlement are poorly understood. Here, we examined the effects of habitat degradation
on fish settlement using a two-stage experimental approach. First, we employed laboratory choice experiments to test how settlers
responded to early and terminal stages of coral degradation. We then quantified the settlement response of the whole reef
fish assemblage in a field perturbation experiment. The laboratory choice experiments tested how juveniles from nine common
Indo-Pacific fishes chose among live colonies, partially degraded colonies, and dead colonies with recent algal growth. Many
species did not distinguish between live and partially degraded colonies, suggesting settlement patterns are resilient to
the early stages of declining coral health. Several species preferred live or degraded corals, and none preferred to associate
with dead, algal-covered colonies. In the field experiment, fish recruitment to coral colonies was monitored before and after
the introduction of a coral predator (the crown-of-thorns starfish) and compared with undisturbed control colonies. Starfish
reduced live coral cover by 95–100%, causing persistent negative effects on the recruitment of coral-associated fishes. Rapid
reductions in new recruit abundance, greater numbers of unoccupied colonies and a shift in the recruit community structure
from one dominated by coral-associated fishes before degradation to one predominantly composed of algal-associated fish species
were observed. Our results suggest that while resistant to coral stress, coral death alters the process of replenishment of
coral reef fish communities. 相似文献
998.
999.
Gen Del Raye Salvador J. Jorgensen Kira Krumhansl Juan M. Ezcurra Barbara A. Block 《Proceedings. Biological sciences / The Royal Society》2013,280(1766)
Many species undertake long-distance annual migrations between foraging and reproductive areas. Such migrants depend on the efficient packaging, storage and utilization of energy to succeed. A diverse assemblage of organisms accomplishes this through the use of lipid reserves; yet, it remains unclear whether the migrations of elasmobranchs, which include the largest gill breathers on Earth, depend on such a mechanism. We examine depth records from pop-up satellite archival tags to discern changes in buoyancy as a proxy for energy storage in Eastern Pacific white sharks, and assess whether lipid depletion fuels long-distance (approx. 4000 km) migrations. We develop new algorithms to assess body condition, buoyancy and drift rate during drift dives and validate the techniques using a captive white shark. In the wild, we document a consistent increase in drift rate over the course of all migrations, indicating a decrease in buoyancy caused by the depletion of lipid reserves. These results comprise, to our knowledge, the first assessment of energy storage and budgeting in migrating sharks. The methods provide a basis for further insights into using electronic tags to reveal the energetic strategies of a wide range of elasmobranchs. 相似文献
1000.
Coral reef fish spend their first few weeks developing in the open ocean, where eggs and larvae appear merciless to tides and currents, before attempting to leave the pelagic zone and settle on a suitable reef. This pelagic dispersal phase is the process that determines population connectivity and allows replenishment of harvested populations across multiple coral reef habitats. Until recently this pelagic larval dispersal phase has been poorly understood and has often been referred to as the ‘black-box’ in the life-history of coral reef fishes. In this perspective article we highlight three areas where mathematical and computational approaches have been used to aid our understanding of this important ecological process. We discuss models that provide insights into the evolution of the pelagic larval phase in coral reef fish, an unresolved question which lends itself well to a modelling approach due to the difficulty in obtaining empirical data on this life history strategy. We describe how studies of fish hearing and physical sound propagation models can be used to predict the detection distance of reefs for settling larval fish, and the potential impact of anthropogenic noise. We explain how random walk models can be used to explore individual- and group-level behaviour in larval fish during the dispersal and settlement stage of their life-history. Finally, we discuss the mutual benefits that mathematical and computational approaches have brought to and gained from the field of larval behaviour and dispersal of reef fishes. 相似文献