Fish inhabiting coral reefs are no different from fish and invertebrate species that breed in coastal areas (Cowen et al., 2000). Shulman and Bermingham (1995) established that if genes flow at high rates, it is plausible to assume that the processes underlying the recruitment of reef fishes are truly dynamic. For a long time, ecologists specializing in coral reefs did not make appropriate assumptions on the breeding patterns as they related to the general population. The common perception was that most of the species did not stop affording parental care to their progenies until the offspring had been on earth for a considerable long period. Empirical evidence has allowed ecologists to revise their assumption about how coral reef populations emerge and sustain themselves over time.
In addition, Shulman and Bermingham (1995) find that the second-last decade of the 20th century saw renewed interest in the variables underlying the dynamics of communal instincts in marine environments; such a surge in interest indicated that scientists had become discontented with the mainstream frameworks that people used to explain community organization among marine species. Before the 1980s, there was no doubt that biotic interactions in communities were the sole driver of organization dynamics. Scientists modeled the biotic interactions as equilibrium arrangements where history had no role (Siegel et al., 2003). After considering history and especially the reproductive aspects of old generations of marine species, scientists started understanding how recruitment and its variation played a big role in shaping community organization and patterns of population growth. In what looked like a strange coincidence, fisheries managers also changed their perception and stopped using the long-term average values of recruitment. There was also the problem of problematic recruitment levels because there did not seem a clear and certain method of recruiting them.
Taking a broad perspective, Jones et al. (1999) find that there is no dispute about the role of natural processes such as competition when it comes to the attainment of equilibrium in marine ecosystems. However, some processes that seem obvious have not assumed the position that everyone ought to accord them. When one looks at communities that have not attained equilibrium, it is clear that disturbances undermine the restoration of the natural states of communities (Swearer et al., 2002). Coral reefs and pelagic fishes comprise some of the best examples of communities that do not attain equilibrium; the evidence for this is clear from the findings of manipulative tests and experiments that have sought to analyze the dynamics underlying the restoration of equilibrium following brief periods of destruction and disturbance.
In scientific experiments, it has become clear that certain interventions will induce specific behavior in coral reefs. For instance, when a scientist removes a species from an artificial habitat and takes it back to its initial natural habitat, there will be no attempt to restore the community structure that existed before the transfer to the artificial habitat. The problems with predicting the community structure of coral reefs meant that managers in the fishing industry had to grapple with the challenge of effective management of fish stocks; nothing exemplifies this challenge better than the problems of some fishing companies do (Cowen et al., 2000).
Comparison and Contrast of Ideas from the Two Papers
Fishing companies noted a sustained decrease in the fish population despite the fact that they had scaled down on their fishing effort. Suddenly, the fishing companies realized that their strategies were pointless as long as they did not attempt to control the way the communities created and sustained equilibrium. Even in marine habitats that witness a low scale of fishing, the species suffer sudden surges in the population, and this shows that short periods of favorable conditions can also create effects to the same level that prolonged periods of good conditions do (Cowen, Paris & Srinivasan, 2006). The minor difference between short and long periods of favorable conditions can only mean one thing: the ecological foundations of sustainable population growth are a good starting point for those that wish to ensure equilibrium.
The absence of equilibrium in reel species points to two factors at play. The first factor is that the habitat of reel species patches over a slope of distant scales, and this means the species have to contend with the restrictions that the extensive patches cause. While the patches that take local positions do have some connection with the distant pelagic larvae, it is not clear if this distance causes changes to the formation of equilibrium (Loya et al., 2001). There is also the issue of eggs failing to hatch in the naturally expected manner that would allow the larvae to transform into pelagic positions. Some reef species have tried to turn around the challenges to attaining equilibrium by increasing the rate at which they spawn in a year.
One would expect that reef fishes, with the tendency to show an aptitude for fecundity, could withstand the challenges that come with attempting to restore the equilibrium position. However, adult fish species tend to stick to local habitats in which the patches have not grown to cover extensive swathes, spawning large numbers of larvae that do not live long. Most importantly, at the pelagic phase, the high stakes resulting from the need to leverage population changes mean that populations that have not attained equilibrium stand no chance to build stable communities (Dulvy, Sadovy & Reynolds, 2003). After the larval phase at which massive dispersal occurs, individuals who withstand all the attendant hazards have an advantage when it comes to selecting a suitable habitat.
However, the process of settling in a new habitat must begin all over again, and the effectiveness with which it happens depends on one factor: the location of the habitat and the distance that the larvae will cover in order to reach that location. While the larvae population largely depends on the existing patterns, the larvae that swim strongly will only do so if the selection patterns seem favorable. In addition, the patterns that larvae follow from the time they start restoring equilibrium means that the composition reef species will turn unnatural (Allison, Lubchenco & Carr, 1998). The movements that the species make after settling can also help yield insights on the final patterns that will define the locations and spatial attributes of new habitats.
Evaluation of the Two Papers
Shulman and Bermingham (1995)’s take is the better one because it is not lost to observers that the way in which larvae interact with old residents in a benthic habitat is one clear indicator of the stakes in play when it comes to the restoration of equilibrium. If settlement varies and it does not affect the rate at which new species are recruited into new communities in order to increase the chances of attaining stability (Jones, Milicich, Emslie, & Lunow. 1999). The rates of settlement among coral reef species tend to mimic the distinct phases of the moon, and in this area, there has not been much dispute. Lunar periodicity clearly manifests itself in the patterns of settlement, and the moments of the full and dark moons witness a reduction in the proportion of old settlers (Caley et al., 1996). There has been speculation about the phenomena underlying the cyclical variation in the rates at which new settlements occur. There is no conclusive answer, but one reason is that the tidal cycles are the main thrust that allows larvae to transit from one settlement to a new one. The tidal cycle itself varies with the phases of the moon, and this simply means that there can never be another reasonable expectation apart from what scientists have tried to speculate about. Environmental cues that people infer from the cycles can help in interpreting relevant patterns.
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