Fisheries Management Techniques
Fisheries resources must be managed to ensure that stocks are harvested at sustainable levels for the benefit of present and future generations. The fisheries resources of New South Wales are very diverse, and many different species are highly regarded by recreational fishers for sport and food, by the commercial sector for their monetary value, and by the community as fresh, quality seafood. As custodian of the resource, NSW Fisheries has the responsibility to manage fish stocks on behalf of the community.
There has been a long held perception that because the commercial fishing sector catch a large quantity of fish it needs to be heavily regulated. Whilst this is certainly the case in some circumstances, there is an increasing recognition that an estimated one million recreational fishers who fish in NSW each year have a significant impact on our fisheries resources. Therefore, it is also important to manage the recreational sector.
Commercial Fisheries Management
Fisheries agencies throughout Australia have traditionally categorised fishery resources into distinct segments for ease of management. This is particularly necessary in NSW because of the large number of species taken for sale, and the range of gear types used by the commercial sector. Commercial fisheries have historically been defined by the method of capture (e.g. prawn trawl and fish trap), however, some of the more valuable fisheries with one target species are defined by the species itself (e.g. abalone and rock lobster).
Once each fishery is defined, policies and legislation can be developed to establish specific rules. These rules may then be included in a management plan for each fishery. Developing a fishery management plan involves extensive consultation with the commercial sector, the recreational sector and the community. In most cases, a specialised committee is established to develop a management plan acceptable to all. This committee comprises NSW Fisheries management and research staff, commercial fishers and recreational fishers.
Commercial Management Tools
There are two broad types of fishery management tools; input controls and output controls. Input controls limit the amount of effort commercial fishers put into their fishing activities, indirectly controlling the amount of fish caught. Input controls can include restrictions on the number of licences, the size and engine capacity of boats, the length and mesh size of nets, and the areas and times which can be worked. In some locations, commercial fishers are not permitted to work during weekends or public holidays.
A good example of how input controls work is the juvenile king prawn closure near the mouth of the Richmond River at Ballina. King prawns live in the estuaries as juveniles and migrate to the ocean during the young adult stage of their life cycle. This makes them vulnerable to capture at a small size by prawn trawlers. To protect the stocks of smaller prawns and to increase the value of the prawns sold, prawn boats are prohibited from trawling within an area bounded by a 2.2 nautical mile radius from the mouth of the Richmond River. This management measure also helps to reduce the capture of juvenile fish in prawn trawl nets.
Output controls, on the other hand, directly limit the amount of fish which can be taken from the water. The first step in implementing an output control management regime is setting a Total Allowable Catch (TAC) for the species. Once established, the TAC can be either fished on a competitive basis or divided up between the participants in the fishery so that all fishers have an individual quota. A TAC which is divided between the participants means that in any one year a commercial fisher is not able to catch more than their allocated weight of that species.
Output controls are generally regarded as good mechanisms to control the total catch in single species, high value fisheries which are targeted using a single gear type (such as abalone and lobster). However, thorough monitoring schemes such as daily catch logbooks are often required to ensure that individual quotas are not exceeded.
Recreational Fisheries Management
The goals of recreational fisheries management differ from those of commercial fisheries, as they have the broader aim of providing for the optimum use and recreational enjoyment of fisheries resources. Management arrangements are put in place both to control the total harvest, and to share the angling experience amongst fishers.
There are many restrictions on the types of recreational fishing gear that are allowed. Anglers are mainly restricted to line fishing methods with limited hook numbers, and a few small nets. These restrictions operate as input controls, as do closures on fishing in certain areas (e.g. marine reserves) and closed seasons (e.g. Murray cod spawning season).
Output controls for recreational fisheries take the form of daily allowable catches (bag limits) and size limits. Bag limits are set to limit the total harvest of certain species to sustainable levels, and to share the catch. In the absence of comprehensive scientific data, they are usually based on an amount of fish which is considered as socially acceptable to take in one day (e.g. enough to feed the average family). For example, anglers are only allowed to keep ten snapper per day.
Setting a minimum size limit is a management tool regularly used to ensure that most of the fish in the population are able to grow to breeding size and spawn at least once before they are caught. For example, the size limit on turban shells in NSW is 7.5 cm, a length at which 100% of the shells sampled were of reproductive age. This attempts to make sure that there will always be juvenile fish available in following years to grow and enter the adult population. Maximum size limits also apply to certain species because larger fish often breed more efficiently than smaller fish (eg. anglers may only keep two mulloway above 70 cm in length, per day).
NSW DPI determines the size limits for each species taking scientific advice about the biology of fish stocks into account, as well as considering consumer preferences and the exisiting sizes taken by commerial and recreational fishers.
Fisheries management will only be effective in the long term if fish habitat is protected. The ever-increasing coastal population has resulted in increased land and water pollution, and greater pressure for coastal development. Much of the increased pressure affects areas near the edges of estuaries and bays, both of which are vital for the survival of juvenile fishes and crustaceans. Under the Fisheries Management Act 1994, NSW Fisheries has a much greater role in deciding whether various developments can proceed.
Education and Enforcement
The effectiveness of fisheries management techniques can be undermined without adequate education and enforcement of the rules. Anglers, commercial fishers and the community need to understand the reasons for, and obey, fisheries policies, legislation and management plans to ensure the resource is exploited at safe and sustainable levels.