3.3 Application of the Ecosystem Approach – Incidental Mortality of Seabirds and Environmental Impacts of Fishing           [return to table of contents]

CCAMLR has tackled three substantial problems relating to mortality of marine animals caused directly or indirectly by the activities of humans, mainly (if not exclusively) relating to fishing. These are:

•  incidental mortality of seabirds in fisheries, particularly longline fisheries;
•  entanglement of marine mammals in marine debris; and
•  impacts of fishing on the seabed.

(i) Incidental Mortality of Seabirds in Fisheries, particularly Longline Fisheries       [return to table of contents]

Longline fisheries were introduced in the mid-1980s to catch Patagonian toothfish. They were initially confined to the waters around Shag Rocks, South Georgia and the Kerguelen Islands. In recent years, however, longline fisheries rapidly expanded to other fishing grounds, many of which are near sub-Antarctic islands with large breeding colonies of albatrosses and petrels or are within the feeding range of these birds. Substantial numbers of albatrosses and petrels die when attempting to take squid or fish bait from hooks attached to lines being set during longline fishing. This poses a major conservation problem for CCAMLR in the Convention Area, as well as in respect of species of interest to CCAMLR in regions to the north of the Convention Area.

The problem has two facets:

• deaths of albatrosses and petrels caused by fishing within the Convention Area; and

• deaths of albatrosses and petrels breeding within the Convention Area but caught by longliners outside it (e.g. in the albatrosses’ wintering areas).

In 1989, the Commission urged all Members conducting longline fishing to introduce, as soon as possible, methods to minimise the incidental mortality of seabirds (particularly albatrosses) arising from the use of longlines. In 1991, CCAMLR adopted the first conservation measure requiring vessels longlining for Patagonian toothfish in the Convention Area to use these methods (especially streamer lines to deter birds from attempting to take baits). The reporting of incidental mortality of seabirds by scientific observers on these vessels was also given much higher priority than hitherto.

In 1993, the Scientific Committee established the ad hoc Working Group on Incidental Mortality Associated with Longline Fishing (WG-IMALF) to review the whole topic, with special reference to the Convention Area and to data reported from vessels fishing in this area. The group’s report to the Scientific Committee in 1994 called attention to the potential seriousness of the problem for Southern Ocean albatrosses and to the fact that they were currently at even greater risk outside the Convention Area than within it. It also noted that the removal of bait by seabirds can reduce the catch of fish significantly and that fishers themselves would benefit from helping to resolve the problem.

After reviewing methods of reducing incidental mortality, CCAMLR decided to include in its conservation measures the requirement that longlines be set at night and that offal discharge (which attracts birds) be prohibited during line-setting. In addition, CCAMLR established the requirement that international scientific observers be present on all longline vessels fishing outside national waters in the Convention Area. In 1995, the ad hoc WG-IMALF, now meeting as part of WG-FSA, emphasised that data from scientific observers were critical to ensure accurate reporting of incidental mortality, that night-time setting of longlines reduced albatross mortality (by about 80%) and that streamer lines, when correctly set, were also effective in reducing catch rates of birds.

Three new concerns were raised:

• Setting at night may increase the numbers of white-chinned petrels (Procellaria aequinoctialis) caught.

• The large number of vessels conducting unregulated fishing operations in the Convention Area (presumably taking no measures to avoid catching birds) is a serious threat to albatrosses.

• Some albatross species are particularly at risk at those times of the year when their foraging areas overlap very extensively with the longline fishery (e.g. black-browed albatross generally and wandering albatross in March–April).

Examination of these problems is continuing.

The most recent data (from the 1997/98 fishing season) confirmed that setting at night-time, combined with the correct use of streamer lines, almost eliminated albatross mortality, but still resulted in some mortality of white-chinned petrels. Large catches of seabirds still occur when vessels set lines during the day, at dusk, or on moonlit nights without using streamer lines.

A comprehensive analysis of the relationship between time of year and risk of albatross and petrel mortality from longline fishing in the Convention Area indicated that moving the opening of the longline fishing season for toothfish from 1 March to 1 May would bring substantial benefits (particularly until all vessels comply with the night-time setting and streamer line requirements). Therefore, in 1997, the Commission agreed to delay the start of longline fishing in most of the toothfish fisheries until 1 April in 1998 and indicated its wish to move the start date to 1 May in 1999. A compromise date of 15 April 1999 was eventually agreed in 1998.

The issue of illegal, unregulated and unreported (IUU) longline fishing was of particular concern at the 1997 meeting of CCAMLR. Ad hoc WG-IMALF estimated that the seabird by-catch in the regulated longline fishery in 1997 had been about 5 700 birds (40% albatrosses; 48% white-chinned petrels) in the Atlantic Ocean sector and about 1 000 birds (23% albatrosses; 73% white-chinned petrels) in the Indian Ocean sector. Based on known relations between fish catch and seabird by-catch and estimates of the fish catch in the IUU fishery, the seabird by-catch in the IUU fishery was estimated at 16 600–26 900 birds (if vessels operated like the average vessel in the regulated fishery in terms of compliance with the conservation measure to minimise seabird by-catch) or 66 000–107 000 birds (if they operated like the least effective regulated vessel). In either circumstance it was clear that seabird by-catch in the IUU fishery was likely to be at least 20 times that in the regulated fishery. This would be unsustainable for the albatross and petrel populations concerned, which include two albatross species (wandering albatross and grey-headed albatross (Diomedea chrysostoma)) of ‘globally threatened’ status. The Commission viewed this as a most serious problem, which it tried to resolve at both its 1997 and 1998 meetings.

Nevertheless, CCAMLR’s prompt action in developing and implementing methods to reduce albatross mortality, coupled with the willingness of many fishing masters to cooperate with scientific observers, has done much to alleviate the problem within the regulated fishery until even more effective long-term solutions (e.g. setting longlines underwater) can be tested and implemented on board all longliners fishing in the Convention Area. To help fishers to minimise the by-catch of seabirds in bottom longline fisheries, CCAMLR has published the booklet Fish the Sea Not the Sky, which describes techniques to avoid seabird by-catch. The booklet has been distributed to all CCAMLR Members, and many international fisheries organisations and fishing companies. It is expected to be held on board longliners fishing in the Convention Area.

CCAMLR has been very active in publicising the plight of Southern Ocean albatrosses and petrels and its efforts to combat the problem in this domain. It has requested many other agencies, conventions and fisheries commissions to take appropriate action in the wintering areas of albatrosses and petrels, particularly in respect of pelagic longlining for tuna and of coastal shelf and shelf-slope longlining for a variety of other fish species.

A second, albeit minor, cause of mortality in albatrosses (and other seabirds) was collision with netsonde cables which are used to monitor the performance of bottom trawls. The Commission prohibited the use of these devices in the Convention Area from the start of the 1994/95 season.

(ii) Entanglement of Marine Mammals in Marine Debris                  [return to table of contents]

Entanglement of marine mammals in debris from humans’ activities is a continuing problem in the Convention Area. In 1989, the Commission was advised that Antarctic fur seals at South Georgia were becoming entangled in marine debris (principally fragments of fishing net) at rates that indicated several thousand were being killed each year. CCAMLR intensified its campaign for compliance with the provisions of Annex 5 of the Marine Convention for the Prevention of Pollution from Ships (MARPOL) in its Convention Area and, in particular, targeted all fishing vessels with information (placards, posters) on the need to avoid jettisoning debris overboard, but if this was unavoidable, to ensure that any material capable of forming loops was cut.

The field program monitoring the incidence of entanglement of Antarctic fur seals at South Georgia showed that the number of animals entangled in nets declined markedly after the introduction of this measure (albeit at a time when trawl fisheries were also decreasing in the area), but that numbers entangled in polypropylene packaging bands increased. CCAMLR then introduced a conservation measure requiring that the use of these bands, used mainly for securing bait boxes, be phased out on fishing vessels by 1995/96 – and on all vessels in the Convention Area by 1996/97. Entanglement rates of fur seals in packaging bands subsequently decreased. Furthermore, most of the few packaging bands washed ashore had been cut before being discarded. The main material entangling fur seals nowadays is fragments of longlines, so there is still a need to remind fishers not to throw any material overboard, especially anything that can endanger the lives of marine animals.

At a more general level, CCAMLR attempts to monitor levels of marine debris in the Southern Ocean by recording, in a standardised fashion, rates at which debris comes ashore on selected beaches in the Antarctic and sub-Antarctic. In general, levels of debris, most of which originates from fishing vessels, have shown little sign of decrease (except possibly as a result of reduced fishing effort in recent years) and are still sufficiently high to indicate that there is much room for improvement in compliance with the provisions of MARPOL by vessels fishing in the Southern Ocean. CCAMLR also requires Members to compile registers of fishing gear lost in the Convention Area.

(iii) The Impact of Fishing on the Seabed                     [return to table of contents]

Most of the finfishing in the Southern Ocean up to the end of the 1980s was conducted with bottom trawls. Trawl gear affects the environment by scraping and ploughing the seabed, which resuspends sediment and destroys benthos (the fauna living in and on the bottom). The richness and diversity of the benthic fauna of the Southern Ocean are comparable to those of tropical regions, with a large number of long-lived and slow-growing forms. The extent of the impact of bottom trawls on the Antarctic benthic fauna and of the destruction of habitats and fish spawning grounds, are unknown. However, any effects are likely to be long-lasting owing to the fragility and slow recovery rate of benthic faunal communities.

To minimise the impact of trawling on non-target species in the fishery and on the seabed, and in accordance with its ecosystem approach, CCAMLR has prohibited the use of bottom trawls in the fishery for mackerel icefish around South Georgia and directed fishing for some demersal fish species that can be taken only by bottom trawls.

3.4 Application of the Precautionary Approach – the Protection of Non-target Species in Trawl Fisheries       [return to table of contents]

(i) Bottom Trawling

The single-species approach, which establishes conservation measures on a stock-by-stock basis, involves a considerable risk for untargeted fisheries, such as bottom trawling, which exploit mixed-species assemblages. As a consequence, many of the species taken as by-catch in the bottom trawl fishery near South Georgia and the South Orkney Islands, such as the humped rockcod, Scotia Sea icefish and South Georgia icefish were overexploited by the mid-1980s.

CCAMLR has improved the conservation of such species by taking a more adaptive approach. TACs for target species are tied to TACs for by-catch species, so that a fishery may be closed when the TAC for one of the by-catch species is reached (even if the TAC for the target species has not been fully exploited). In other cases, fishing a target species may either be prohibited due to the risk of depleting by-catch species, as is the case of the mackerel icefish fishery around the South Orkney Islands, or be permitted only if conducted by midwater trawling, which produces low by-catches of non-target species.

(ii) Midwater Trawling for Krill                         [return to table of contents]

Krill is harvested in midwater with fine-mesh trawl nets. Krill catches can sometimes include a substantial by-catch of larvae and juvenile fish, such as mackerel icefish on the South Georgia shelf. By-catches are often largest when less dense or scattered krill aggregations are being fished. It is unknown whether the extent of the by-catches, for example of mackerel icefish, impair recruitment. The by-catch of juvenile fish may become a critical issue when the spawning stocks of exploited species have been reduced to such low levels that recruitment starts to decline.

CCAMLR has requested Members who fish for krill in the Convention Area to provide information on the by-catch of juvenile fish in the krill fishery, and has developed a standard protocol for scientific observations on board krill trawlers. The first results from these investigations suggested there are large spatial and seasonal differences in the occurrence of fish in krill catches, which makes it extremely difficult to assess the extent of these by-catches and their effects on the recruitment of fish stocks. Moreover, most of the studies have been undertaken during the austral summer. CCAMLR has asked Members to intensify their investigations into the by-catch of juvenile fish and to extend them to other seasons so that CCAMLR can assess more precisely where and when fish are most vulnerable to the krill fishery, and take appropriate action.

3.5 Application of the Precautionary Approach – New and Exploratory Fisheries              [return to table of contents]

The preceding sections have examined two key elements in CCAMLR’s approach to management – the ecosystem and precautionary approaches. In accordance with the latter, CCAMLR has recognised that fisheries should be managed from the outset, and has adopted conservation measures that set out requirements for any Member planning to initiate a fishery for any species, or in any area, that has not previously been exploited (Figure 19). At this ‘new fishery’ stage, the measures require that Members notify CCAMLR of their intention to start a new fishery and supply information on the nature of the proposed fishery and as much as they can on the biology of target species and the possible effects of the fishery on any dependent and associated species. In such cases, CCAMLR has limited catch or fishing effort (or both), and has also made scientific observation of the fishery obligatory. The conduct of a new fishery is limited to the Member(s) who made the notification(s).

A new fishery is designated an ‘exploratory fishery’ after its first year. The conservation measure that the Commission has implemented for exploratory fisheries allows for continued regulation of the fishery while the scientific information required for a full assessment of the fishery and stock(s) concerned is being collected. A major component of the exploratory phase is the implementation of a plan to collect the data required for such an assessment (Figure 19).

CCAMLR aims to ensure that an exploratory fishery is not allowed to expand faster than the information to manage the fishery in accordance with the principles of Article II is collected. To ensure information is adequate, the Scientific Committee is required to develop (and update annually as appropriate) a Data Collection Plan. This plan identifies the types of data required and how to obtain them from the exploratory fishery. Participating Members are required to provide a Research and Fishery Operation Plan for review by the Scientific Committee and Commission, as well as to submit annually the data specified by the Data Collection Plan. The Scientific Committee also sets a precautionary catch limit at a level not substantially above that necessary to obtain the information specified in the Data Collection Plan and to undertake assessments and evaluations.

CCAMLR’s discussions about new and exploratory fisheries have highlighted the need to clarify the decisions and management procedures at the various stages of fishery development. In particular, the focus has been on developing uniform criteria for the resumption of ‘lapsed’ fisheries (i.e. those that have ceased operating for some period) and ‘closed’ fisheries (i.e. fisheries closed by a conservation measure) (Figure 19). While there is fundamental agreement with the general principle that a notification procedure (as for new and exploratory fisheries) should be followed for the resumption of closed or lapsed fisheries, the details of how and to what extent additional procedures (e.g. for data collection) should be implemented have yet to be finalised.

4. Conclusion                    [return to table of contents]

CCAMLR stands at the forefront in the development of precautionary and ecosystem-based fisheries management. The various scientific initiatives and details explained in this document represent the current wisdom within the CCAMLR Scientific Committee at the time of writing. However, it should be obvious that much of the work outlined is only in an early stage of development and its impact will only be assessable at some time in the future. The key challenge therefore is to ensure that the Scientific Committee not only communicates its findings to the rest of the world, but that it also keeps abreast of global developments in fisheries management.

Despite its perceived simplicity compared to other systems, the Antarctic marine ecosystem is as complex as any and its dynamics are further complicated by a harsh and variable environment. The added complexity of human activities has not served this ecosystem well in the past, and CCAMLR’s precautionary approach to management was a novel attempt to ensure that future exploitation of Antarctic marine living resources do not repeat the excesses of recent history in the area. This has posed a grave challenge for the scientists involved in formulating CCAMLR’s management advice. Consequently, the approach developed has had to be dynamic and has had to take account of high levels of uncertainty in a way which strives to ensure effective practical implementation. Understanding CCAMLR’s Approach to Management serves as a benchmark as well as an attempt to publicise the work of the Scientific Committee in a way which is both understandable and comprehensive.