Determining a sustainable harvest in a variable environment
- % of MSY (quota system)
Strictly speaking, this is a ‘fixed quota’ system because the number harvested doesn’t vary unless there are no longer enough animals to harvest. Sinclair et al. (2006; in Chapter Wildlife Harvesting, pp. 335-354) suggest a harvest rate of 25% below MSY may produce a sustainable harvest in a variable, resource-limiting environment.
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| % of MSY | ||||||||||
| 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% | 100% | |
| N at 2001 | 713 | 647 | 575 | 498 | 413 | 319 | 208 | 55 | 0 | 0 |
| Total off-take | 378 | 756 | 1134 | 1512 | 1890 | 2268 | 2646 | 3007 | 2958 | 1658 |
| Total $$ | 175809 | 351393 | 526690 | 701608 | 875988 | 1049523 | 1221427 | 1379818 | 1350121 | 745616 |
- % of N (adaptive harvest system)
Another approach to calculating harvest yields is the adaptive approach in which a set proportion of the previous year’s population is harvested each year.
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| % of N | ||||||||||
| 2% | 4% | 6% | 8% | 10% | 12% | 14% | 16% | 18% | 20% | |
| N at 2001 | 671 | 572 | 480 | 396 | 320 | 252 | 192 | 140 | 97 | 63 |
| Total off-take | 886 | 1607 | 2170 | 2580 | 2845 | 2974 | 2982 | 2887 | 2712 | 2487 |
| Total $$ | 412192 | 747173 | 1007241 | 1195270 | 1314943 | 1371127 | 1370367 | 1321448 | 1235743 | 1126871 |
Costs of Harvesting
The below-provided information is regarding the selection of one method from the studied two methods based on the information and the question regarding the two methods – a fixed (% of MSY) system and a variable (% of N) system, information that has been gathered after researching and obtaining the required knowledge on the topic that is the method that will be best suitable to the Aboriginal group, are as follows: The two methods which have been explained in this project consist of (A). Fixed (% of MSY) system and (B). variable (% of N) system. After realizing the pros and cons of the method a better decision can be provided for the group, and their summary of the advised method has been explained below. % of N would be a better option in comparison to the % of MSY, and it would be the first recommendation to the group with the percentile of 10%. The method of the % MSY is based on fixed figures and data, such a thing would be a better choice for those places which are having constant environmental conditions but for those places that are constantly changing % of N has to be a better option for the desired result. % of N also allows us to set the percentile based on the growing population of the buffalo. And due to this flexibility can be achieved but on the other hand, it will not be possible with the % of MYF method and could lead to overharvesting when the population is low.
The two options that can be provided for the community that is a fixed (% of MSY) system and a variable (% of N) system and at the specific rate of harvest that can be recommended for each system are as follows: % of N has been chosen with the 10 % the reason behind taking the 10 per cent is that it will allow the harvesting and birth rate in control so that there won’t be a scenario in which the population is low over high. Buffalo harvesting can be done by this method. For the full justification of the answer, a discussion of the implications of the strategies that have been recommended and the likely effects of variable rainfall on these outputs have been provided below: a variable harvesting system that is % of N with the % taken as the 10c can provide the desired result. This method of harvesting is suitable as it has been already explained above due to the flexibility it offers, and it will result in constant availability and scenarios in which abnormal growth will not be found. The explanation for the case of what can happen in the scenario when market prices change is explained below when the population is low then it will directly affect the profits and they will be low too for the case in which the population is high there will be high profits it is directly proportional to each other. The below-provided graph shows the population trajectories under the 2 different harvest regimes along with the recommended harvest rates while considering the rainfall data from 1960 until 2001 it is to check the level of similarity and differences for future trajectories likely to be has been explained by taking % of N is equal to 10:
The above-provided graph shows the rate of population from 1960 to 2001 based on the variable method taking the % of N to 10. And this is the graph obtained by it. The graph is clearly showing and justifies the reason why it is good to consider the variable method over the other fixed method of % of MYF. From the above information that has been researched and obtained for the project work, it can be concluded that the methods which suit best depend on the environment and both the methods are suitable based on the factors present in the surrounding as for this scene when the environment is constant on changing variable method is more suitable for it with the 10 % of N.
The references have been provided below that have helped in getting the desired result in this research work and this is as follows:
- Altman, J., 2018. The Indigenous hybrid economy: A realistic sustainable option for remote communities?.
- Russell, S., Power, M. and Ens, E., 2020. Cryptosporidium and Giardia in feral water buffalo (Bubalus bubalis) in the South East Ammmmm land indigenous protected area, Australia. Parasitology Research, 119(7), pp.2149-2157.
- From the provided two proposed harvest strategies that are as follows, (% of MSY & % of N) and why they can be recommended along with what can be recommended as follows: as it has been a variable method that is the first taken approach by the aboriginal community but the advised method to them will Fixed method. Below provided information shows the points including the advantages and disadvantages that are for the Aboriginal community including the fixed and variable harvest system for the buffalo in the given environment has been explained below: starting from the first advantage of the method over others is that, there will be better planning could be done as the number of harvest for each will not change this means that there is less requirement of the high management is required, based the ongoing year’s necessary changes can be done. A second big reason for selecting this method as it will lead to solving the problem of over-harvesting. These are some examples of the advantages, on the other hand, the disadvantages that it shows are as follows: due to the fixed amount it will lead to loose the potential profit which can be gathered by the other method but no in this is one of the disadvantages of this method. Another disadvantage of this method is that changes in the population size will not be managed and could result negatively. These are some advantages and disadvantages of the recommended method for harvesting buffalo although the method is suitable for this is % of MYF.
The harvest regime that has been provided is after doing the necessary research that gives the desired result but in terms of the longer-term sustainability of the method points to take into consideration are as follows: the variable harvest regime based on a % of N is the recommended method for this. This is because it would allow the Aboriginal community to adjust the harvest on the basis of the rate in response to changes in population size. A fixed harvest regime based on a % of MSY leads to overharvesting in years with high rainfall and population growth and under harvesting in years with low rainfall and population decline. To make sure the long-term sustainability of the buffalo population it is important to monitor the population size and adjust the harvest rate accordingly. By adjusting the harvest rate based on population size, the Aboriginal community can ensure that the population is not overexploited and that sufficient individuals are left to maintain the genetic diversity of the population. There are other factors that also do matter in the growth and population of the buffalo yet the selected method includes all those factors and is assumed to be a better and recommended decision. From the above-gathered information, this can be concluded that the variable harvest based on a % of N is the most sustainable option for the Aboriginal community to manage the buffalo population in the long term. This approach allows for flexibility in adjusting the harvest rate based on population size and rainfall patterns, ensuring that the population is not overexploited and can maintain genetic diversity. However other factors such as habitat quality, predation, and disease also need to be considered to ensure the long-term sustainability of the buffalo population.