As living populations or communitie

As living populations or communities, aquatic living resources are capable of on-going renewal through the processes of growth in size and mass of individuals and additions to the population or community through reproduction (leading to what in fisheries is often called ‘recruitment’). In a population at equilibrium, the additive processes of growth and reproduction on average equal the loss process of total mortality. In an unexploited population, total mortality consists only of natural mortality, made up of processes such as predation, disease, and death through drastic changes in the environment. In a fished population, total mortality consists of natural mortality plus fishing mortality, and a primary task of fisheries management is to ensure that fishing mortality does not exceed the amount which the population can withstand, in addition to natural mortality, without undue harm or damage to the sustainability and productivity of the population. This requires not only that the total population is maintained above a certain abundance or biomass, but also that the age structure of the population is maintained in a state in which it is able to maintain the level of reproduction, and hence recruitment, necessary to replenish the losses through mortality. Further, fishing over a long period on selected portions of a stock, for example large individuals or individuals spawning at a specific time or locality within a wider spawning season or range, can reduce the frequency of the particular genetic characteristics giving rise to that feature or behaviour. This has the effect of reducing the overall genetic diversity of the stock. With reduced genetic diversity, the production potential of the population can be adversely affected and it may also become less resilient to environmental variability and change. Fisheries management needs to be aware of this danger and avoid maintaining such selective pressures over a prolonged period.

Achieving an appropriate level and pattern of fishing mortality is hindered substantially by difficulties in estimating population abundance and population dynamics rates and the variability in these rates. The fisheries manager must, however, have sufficient knowledge to make good decisions. The Code of Conduct specifies (Paragraph 7.2.1): “...States... should, inter alia, adopt appropriate measures, based on the best scientific evidence available, which are designed to maintain or restore stocks at levels capable of producing maximum sustainable yield, as qualified by relevant environmental and economic factors...” and further (Paragraph 7.5.2, referring to the Precautionary Approach) “In implementing the precautionary approach States should take into account, inter alia, uncertainties relating to the size and productivity of the stocks, reference points, stock condition in relation to reference points, ...”. These issues are discussed in Chapter 5.

Fishery managers must also respect the stock structure of the resources. Fish populations are frequently made up of a number of different stocks, each of which is genetically largely isolated from the others through behavioural or distributional differences. The different stocks also reflect genetic diversity and if a particular stock is fished to extinction or to very low levels, this genetic diversity may be lost. The stock will not readily be replenished from other stocks, because of the genetic isolation, and therefore the production it was generating will also be lost, leading to a permanent or at least long-term loss of benefits. Fisheries management should therefore attempt to address each stock separately and to ensure sustainable use of each stock and not just of the population as a whole. In this regard, the Code of Conduct states (Paragraph 7.3.1): “To be effective, fisheries management should be concerned with the whole stock unit over its entire area of distribution and take into account previously agreed management measures established and applied in the same region, all removals and the biological unity and other biological characteristics of the stock.”

Hasil (Bahasa Indonesia) 1:

Sebagai populasi hidup atau masyarakat, sumber daya air hidup mampu terus-menerus Pembaharuan melalui proses pertumbuhan dalam ukuran dan massa individu dan penambahan penduduk atau masyarakat melalui reproduksi (memimpin apa di perikanan yang sering disebut 'perekrutan'). Dalam populasi keseimbangan, aditif proses pertumbuhan dan reproduksi rata-rata sama dengan proses penurunan dari kematian. Dalam populasi yang asri, mortalitas total hanya terdiri dari kematian alami, terdiri dari proses predasi, penyakit dan kematian melalui perubahan drastis dalam lingkungan. Dalam populasi penuhi, mortalitas total terdiri dari kematian alami ditambah Memancing kematian, dan adalah tugas utama dari pengelolaan perikanan untuk memastikan bahwa kematian Memancing tidak akan melebihi jumlah yang dapat menahan penduduk, selain kematian alami, tanpa kerugian yang tidak semestinya atau kerusakan keberlanjutan dan produktivitas penduduk. Ini tidak hanya mensyaratkan bahwa total populasi dipertahankan di atas kelimpahan tertentu atau biomassa, tetapi juga bahwa struktur umur penduduk dipertahankan dalam keadaan di mana itu mampu mempertahankan tingkat reproduksi, dan karenanya perekrutan, diperlukan untuk mengisi kerugian melalui kematian. Lebih lanjut, Memancing selama jangka panjang pada bagian-bagian yang dipilih dari saham, misalnya besar individu atau individu hal ikan bertelur di waktu tertentu atau wilayah dalam lebih luas pemijahan musim atau kisaran, dapat mengurangi frekuensi karakteristik genetik tertentu menimbulkan fitur atau perilaku. Ini memiliki efek mengurangi Keragaman genetik keseluruhan saham. Dengan mengurangi Keragaman genetik, potensi produksi dari populasi dapat terpengaruh dan hal ini mungkin juga menjadi kurang tahan terhadap lingkungan variabilitas dan mengubah. Pengelolaan perikanan perlu menyadari bahaya ini dan menghindari mempertahankan tekanan yang selektif demikian selama jangka waktu yang lama.Achieving an appropriate level and pattern of fishing mortality is hindered substantially by difficulties in estimating population abundance and population dynamics rates and the variability in these rates. The fisheries manager must, however, have sufficient knowledge to make good decisions. The Code of Conduct specifies (Paragraph 7.2.1): “...States... should, inter alia, adopt appropriate measures, based on the best scientific evidence available, which are designed to maintain or restore stocks at levels capable of producing maximum sustainable yield, as qualified by relevant environmental and economic factors...” and further (Paragraph 7.5.2, referring to the Precautionary Approach) “In implementing the precautionary approach States should take into account, inter alia, uncertainties relating to the size and productivity of the stocks, reference points, stock condition in relation to reference points, ...”. These issues are discussed in Chapter 5.Fishery managers must also respect the stock structure of the resources. Fish populations are frequently made up of a number of different stocks, each of which is genetically largely isolated from the others through behavioural or distributional differences. The different stocks also reflect genetic diversity and if a particular stock is fished to extinction or to very low levels, this genetic diversity may be lost. The stock will not readily be replenished from other stocks, because of the genetic isolation, and therefore the production it was generating will also be lost, leading to a permanent or at least long-term loss of benefits. Fisheries management should therefore attempt to address each stock separately and to ensure sustainable use of each stock and not just of the population as a whole. In this regard, the Code of Conduct states (Paragraph 7.3.1): “To be effective, fisheries management should be concerned with the whole stock unit over its entire area of distribution and take into account previously agreed management measures established and applied in the same region, all removals and the biological unity and other biological characteristics of the stock.”