Several hundreds of years ago people all over the world came to the conclusion, that fisheries should be under proper control and management regulations. There is a number of techniques and methods that can be applied in order to prevent too high rates of fish mortality. The problem of overfishing was for the first time raised during the first Overfishing Conference that took place in London in 1936. After the year 1957, when Ray Beverton and Sidney Holt (the British researchers of fisheries) published their theoretical work on North Sea commercial species fisheries dynamics, this problem became even really burning (Jackson, 2001). Later on this work served as a theoretical basis for the new approaches in management of fisheries.
The main political and economical aims of fisheries control and management can be united under:
Political objectives often found when exploiting a fish resource:
Maximize sustainable biomass yield (see maximum sustainable yield)
Maximize sustainable economic yield (see optimum sustainable yield)
Secure and increase employment in certain regions
Secure protein production and food supply
Increase income from export (Rosenberg, 1993).
In this paper we will try to define and to discuss the best possible ways and methods for reducing fish mortality and evaluate their possible socio - economical outcomes.
The necessity of the proper control of fisheries can be confirmed both theoretically and practically based on the investigations and studies done in fish stocks and fisheries. Theoretically, two types of management and control activities there could be separated: restraint and control of the total amount of fishing and control of the size and other characteristics of the caught fish (Gulland, 1968). This is also without any doubt, that fisheries control and management have strong impact on both biological and economical situation. For several decades the correlation between economics and biology were accepted and supported by biologists and economists, for example: Crutchfield 1959, Gordon 1954, and Graham 1935, Beverton 1953 (Jackson, 2001). This means, that all the steps and decisions, aimed at improving the situation with fishing mortality, should presume benefits and positive outcomes for reducing the fishing mortality as a biological factor, at the same time taking into consideration the effectiveness and minimal losses of the economy of fishing operations.
As researches proved, it is not so easy to evaluate and to measure the fishing mortality, especially if to study it within a short period of time. In order to make this procedure easier and quicker it was necessary to distinguish some other items or quantity that could be measured and controlled in a better way. The options could be either catch or fishing effort or the continuance of fishing.
Talking about long-lived species it is necessary to keep in mind, that although being very hard to predict, the fluctuations are not really serious (Scott, 1955). This means, that even if there are several months, when the mortality is rather high, this can be later regulated by lower catch or nominal effort. So in order to make the forecast for the coming year, it can be enough to collect and analyze the information about age composition of the commercial catch of the previous year in order to define the amount of young fish (Rosenberg, 1993). The theoretical side of the issue seems to be rather simple, but to study the practical one, we have to take into consideration several important points: there should be used the corresponding machines in order to make clear and quick investigation, the allowed level of catch should correspond the future seasons, “obtaining adequate estimates of the strength of year-classes among the youngest fish” (Jackson, 2001).
After the process of measuring the fishing mortality and in case the results prove, that it is too high, the way to control of the fishing mortality should be chosen. In fact there are several ways of fishing mortality control:
- everybody is prohibited to fish for some certain period of time
- some people are not allowed to fish at all – practically restraining the groups of people who have the entry right
- restricting the types of gears allowed to be used for fishing.
- everybody may fish without any time restrictions, but their activities are limited
- combination of the above mentioned techniques.
The first of the above mentioned methods used to be rather widespread and got the second name – “single quota”. Mostly it was applied for international fisheries. To the examples of this restriction technique belongs yellow fin tuna in the East Pacific (Scott, 1955). Some researchers state that this type of control is more related to catch than to effort. In reality on the basis of the example with yellow fin tuna we could sooner consider the effort of 30.000 days than catch of 100.000 tons.
There is a number of benefits in using this method, like for example there is no chance for anybody to be discriminated in the sense of allowing some certain people fish while the others are prohibited to do it during the so-called open season. It is also much easier to control the complete banning of fishing in comparison to the partial prohibition.
Speaking about negative economic outcomes of the single quota system, it is necessary to mention, that nobody is able to fully control the fishing capacity of the vessels. Along with increase of fishing profitability new ships will be involved into fishing activity. This may lead to the growth of the catch and thus correspondingly to shortening of the season. The example of the Antarctic baleen whaling proved that the season changed from 121 days in 1945 to 58 days ten years later (Scott, 1955). As soon as the fishing season gets shorter we can expect the increase of the fishing cost that includes: “capital costs of ship and equipment; running costs; and crew costs - an also on the degree to which some of the fixed costs can be spread over alternative operations during the closed season” (Gulland, 1968). After the season is shortened till the point, when the value of the catch equalizes the fishing cost, the economical advantages, brought by this type of regulation disappear.
In case, when other methods of fishery control can not be applied, restrains of gear efficiency are used. The deterioration of the effort can at least lead to increase of “total catch by preventing the mortality increasing beyond the value giving the maximum” (Gulland, 1968). The economical advantages of controlling the type of gear, compared to the situation without any restrictions, are evident and could be proved with the help of a simple example. If we take several fishermen and let them completely utilize the stock of fish and assume that they don’t have any variant of other activity to earn money available. Then, the gill-nets used instead of purse-seines as more advanced equipment will contribute to the increase of efficiency and at the same time increase of catches, which certainly will be positively reflected on the income of these fishermen. This will also help to cover the extra costs of the new gear used. This effect is however rather short-term, because as soon as somebody buys a new gear, the other people involved into this type of activity will follow his example and will also start to use the new gears. Thus it can be again concluded, that in comparison to doing nothing, the restriction of the advanced gears is much more rewarding. This type of banning can also contribute to creation of more working places, whereas in case of using new gears less people are involved.
The above-mentioned method of limited entry has also both benefits and disadvantages. One of the main problems related to it is the problem of allocation - inside one country and among countries. In case if some country is not the only one fishing on a certain stock the method of entry restriction can be used only in the situation when the system of allocation exists between the countries. The countries, which have the common shares of the effort or catch, are not forced to operate a limited entry system on a national scale (Scott, 1955). One of the main advantages of this system is that countries gain pliability in national regulations. “This flexibility is obviously important in allowing a variety of countries with very different social, political and economic conditions (e.g. Spain, Germany, Canada and USSR in the Northwest Atlantic cod fisheries) to pursue their varying national objectives.” (Rosenberg, 1993).
Also potential advantage of the method for economy could be the use of licenses – i.e. permissions for vessels for fishing, especially if they are issued for limited period of time.
On the other hand, this will make the procedure more difficult for the small fishing campaigns, as only the biggest and the most powerful would have the better chance to get the license and develop their activity.
In fact there is no agreement concerning the effectiveness either of single quota system or limited entry technique or any other method if applied separately. They all have benefits and disadvantages for economical development and social situation. The most rational and rewarding still seems to be the mixture or combination of several regulations. As there are a lot of aspects to be taken into consideration in fisheries, the single regulations may be used in order to help to control most of them, as for example the single quota could be applied for better fishing mortality control, at the same time limited entry would contribute to controlling the exuberance fishing capacity and so on.

References
Gulland, J.A. (1968). Concept of the maximum sustainable yield and fishery management.
FAO Fish. tech. Pap., (70). Pp. 13 - 42
Jackson, J. B. C. (2001).Historical overfishing and the recent collapse of coastal
ecosystems. Science.pp. 629–638
Ludwig, D., Hilborn, R. & Walters, C. (1993). Uncertainty, resource exploitation, and
conservation: Lessons from history. Science. Pp. 17–18
Rosenberg, A. A., (1993). Achieving sustainable use of renewable resources. Science 262.
pp. 828–839
Scott, A. (1955). The fishery: the objective of sole ownership. J. polit. Econ., 63(2).pp. 116-
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