Current state and trends

Fisheries

More than 1,300 commercial fishing vessels operate in New Zealand’s marine environment (Ministry of Fisheries, 2007c). The commercial fishing sector accounts for the most significant proportion of the annual fisheries catch, catching 525,000 tonnes of fish in the 2006 fishing year. This includes fish caught both inside and outside of the New Zealand quota management system, including hoki, squid, jack mackerel, southern blue whiting, barracouta, and orange roughy. These species make up 60 per cent of the total catch by weight.

One hundred and thirty species are commercially fished in New Zealand. Of these, 96 species, comprising 618 fish stocks, are managed under New Zealand’s quota management system (Ministry of Fisheries, 2007c). About 40 species have quota management system allowances for customary Māori fishers, and a similar number have allowances for recreational fishers (Ministry of Fisheries, 2007a).

While the quota management system ensures good information is collected about commercial fishing in New Zealand, recreational fishing catches are not formally reported. However, surveys are periodically conducted to estimate the quantity and type of species caught. For some fish stocks, the recreational take represents a large proportion of the total catch. For example, in the year ending 30 September 2005, the estimated recreational catch for blue cod in some management areas, such as the Marlborough Sounds, far exceeded the commercial landings (Ministry of Fisheries, cited in Statistics New Zealand, 2007a).

The quota management system also cannot track and report on unregulated and illegal fishing in New Zealand waters. Illegal fishing can limit the availability of fish for all fishers, particularly high-value species such as rock lobster and pāua.

Fishing is the most widespread human activity in the marine environment.

 

Source: Nature's Pic Images.

Māori fisheries

Māori have a significant interest in New Zealand fisheries, controlling more than 35 per cent of the commercial fishing industry.

Māori also control the customary take of marine species provided for under the Fisheries (Kaimoana Customary Fishing) Regulations 1998 and Fisheries (South Island Customary Fishing) Regulations 1999.

Tangata kaitiaki or tiaki (customary-take guardians)

Iwi and hapū elect tangata kaitiaki or tiaki (customary-take guardians) for each area, whom the Minister of Fisheries then appoints formally.

Tangata kaitiaki may authorise any individual to take fisheries resources for customary use from within the rohe moana (coastal and marine area) for which the tangata kaitiaki have been appointed.

Iwi must report catches regularly to the Ministry of Fisheries so customary use can be factored in when annual catch limits are set.

Customary fisheries restrictions and closures

Provision for customary fisheries restrictions and closures is made under the Fisheries Act 1996 (Ministry of Fisheries, 2007a). This includes the use of rāhui, mātaitai reserves, and taiāpure.

Rāhui is a traditional marine management tool that temporarily closes an area. Tangata whenua may ask for mātaitai reserves (special management areas) and taiāpure (locally managed fishing areas) to cover some of their traditional fishing grounds or areas that have cultural and spiritual significance.

Within mātaitai reserves, tangata kaitiaki set the rules for customary and recreational fishing. Generally, commercial fishing is banned within mātaitai reserves. However, tangata kaitiaki may recommend that some types of commercial fishing be allowed (Taylor and Buckenham, 2003).

Taiāpure are local fisheries in coastal waters that recognise the special significance of the area to local iwi or hapū, either as a source of seafood or for spiritual or cultural reasons. Taiāpure give Māori greater say in the management of their traditionally important areas.

A major difference between mātaitai reserves and taiāpure is that commercial fishing is often allowed in taiāpure (Department of Conservation, 2007).

Status of commercial fish stocks

In 2006, 65 per cent by weight of all commercial catches were from fish stocks where enough information was available to assess the stock status (99 fish stocks).¹¹

The remaining 35 per cent comprised 519 stocks, the status of which could not be assessed because of insufficient information. For many of these fish stocks, there is presently no way to assess their status, as long-term data is needed for a meaningful assessment. Many of these stocks record catches of less than 10 tonnes each year, so they are not considered at risk of over-fishing.

Table 11.1 shows that of the 99 assessed fish stocks, 85 per cent (84 fish stocks) are near or above target biomass levels. This includes all stocks in the ‘near or above’, ‘probably near or above’, and ‘possibly near or above’ target level categories.

The remaining 15 per cent of assessed fish stocks are below target levels. Rebuilding strategies are in place for these fish stocks. They include, for example, orange roughy in the Puysegur area (which has been closed to fishing since 1997) and rig (a shark-like species) in areas where the allocated catch has been reduced.

Table 11.1: Status of assessed fish stocks under the quota management system relative to target levels, 2006

Data source: Adapted from Ministry of Fisheries, 2007b.

Seabed trawling

Trawling on or near the sea floor is the most widespread fishing activity in the New Zealand marine area that physically affects the seabed. From 1990, trawl effort by vessels required to report accurate fishing locations (TCEPR vessels) increased from fewer than 40,000 sweeps by trawls per year by about 127 vessels to a peak in 1998 of almost 80,000 sweeps per year by 173 vessels. In 2005, this number had dropped to nearly 55,000 sweeps per year by 94 vessels.

At the same time, the total area swept increased from 35,000 square kilometres in 1990 to a peak of more than 67,000 square kilometres in 1998. On average, the total area swept remained between 55,000 and 62,000 square kilometres in subsequent years until 2004 (see Figure 11.2). By 2005, the area swept had decreased to about 50,000 square kilometres, probably due to reductions in the total allowable catch for some species.

On average, around 55,000 square kilometres were trawled each year between 1990 and 2005.

Figure 11.3 reports on where commercial trawling effort occurred in New Zealand by showing the total area swept (in square kilometres) in each 25-square-kilometre ‘cell’ fished. Sixty-four thousand of these cells are in fishable depths (less than 1,600 metres deep). Overall, 58 per cent of cells at fishable depths were crossed by at least one trawl over the 16 years for which there is data.

Trawling effort by year rose from 20 per cent of fishable cells in 1990 to 30 per cent in 2002, and then decreased to 25 per cent in 2005. The data shows the majority of the fished cells have had less than 1 square kilometre swept by trawls over the 16 years.

Figure 11.3 shows that many areas in the EEZ are not targeted by trawling. Even if the area is of a fishable depth, catches may not be high enough to be economic.

Areas of higher trawling intensity are those where hoki, squid, orange roughy, scampi, or snapper are targeted.

The distribution of trawl effort changes from year to year, but the data does show a pattern of initial expansion of trawl effort to the east and south of New Zealand. This initial expansion is mainly due to trawl effort targeted at hoki, although this has contracted in recent years (as the hoki catch has decreased).

Demersal Fish Community Classification

Demersal fish live near the seabed. Figure 11.4 shows the 16 classes in the Demersal Fish Community Classification. Each class represents a different demersal fish community and is shown by a different colour in Figure 11.4. The darker shades show where the various classes (and their fish communities) have been affected by trawling.

Figure 11.5 shows the percentage of cells within each class of the Demersal Fish Community Classification trawled at least once between 1989 and 2005. That some of these classes have a higher proportion of trawled cells than others may indicate that the associated demersal communities may also have been exposed to a greater extent of fishing.

Note that inshore classes are comparatively under-represented in Figure 11.5. This is because smaller vessels that do not use Trawl Catch Effort Processing Returns (TCEPRs) are more likely to fish inshore.

Demersal fish communities in the northern coastal, northern shelf, central shelf, Chatham Rise 1, and Chatham Rise 3 classes have had the highest proportion of their area (40–56 per cent of their cells) trawled by TCEPR vessels at some time in the 16-year period (see Figure 11.5). This does not necessarily reflect a higher level of trawling, as a trawled cell may have been trawled only once in the past 16 years.

Water quality at coastal swimming spots

Over the summer season, popular swimming and recreation beaches throughout New Zealand are regularly tested for water quality.

 

Source: Ministry for the Environment.

Figure 11.6 shows that over the 2006–2007 summer, water quality at 80 per cent of the 380 monitored beaches met the New Zealand guidelines for contact recreation almost all the time (at least 95 per cent of samples taken at these sites had safe enterococci concentrations). One per cent of sites breached guidelines regularly (more than 25 per cent of samples were non-compliant), indicating these beaches are often unsafe for swimming.

Figure 11.6 shows that more beaches met the guidelines in the 2006–2007 summer season than in previous summer seasons for which we have national data (2003–2004 and 2005–2006). While this is encouraging, the period for which we have data is not long enough to show whether the improvements in recreational water quality are a trend, or merely annual variations.

Several factors may cause variations in recreational water quality. For example, during a wet summer, more faecal matter is carried from the land into rivers and streams and out to the coast. Therefore, bacteria levels in coastal waters during wet summers are often high compared with levels in dry summers. Windy or stormy conditions can also lead to elevated bacteria levels, because increased wave action lifts sediment from the seabed, which may release faecal matter.

Coastal beaches generally have lower background levels of bacteria and/or shorter lasting bacterial contamination events than river and lake swimming spots. This difference is largely due to pollutants being more rapidly diluted and dispersed by currents and the large volumes of water at the coast.

More about marine pollution

Marine pollution, from various sources, has the potential to affect marine biodiversity and habitats. Pollution includes marine debris, litter from land, run-off from land into coastal ecosystems, and oil spills.

Most oil spills occur in ports and harbours as a result of the high volume of shipping traffic. The spill rate for ports is about three times higher than the spill rate for all other coastal areas. Although oil spills from ships must be reported by law, most marine oil spills are from unknown sources and the volume of oil cannot be measured.

Figure 11.7 shows a decrease in the number of reported spills since 1999, possibly due to improving practices in the fishing and shipping industries. It is notable that in spite of a significant increase in shipping and tourism activities in recent years, there has been no large-scale marine spill in New Zealand since 2002.

It is possible that some spills continue to go undetected or are unreported.

Figure 11.7: Total number of reported marine spills, 1999–2006

 

Note: Spills of all sizes, sources, and types are aggregated.

Source: Maritime New Zealand, 2007.

Text description of figure

Year	1999	2000	2001	2002	2003	2004	2005	2006
Total no of spills	138	164	148	117	108	101	88	82

Threatened marine species

Several of New Zealand’s marine species are on the New Zealand Threat Classification lists (Hitchmough et al, 2007). In addition, several migratory marine mammals and seabirds that pass through New Zealand waters are on the IUCN Red List (International Union for the Conservation of Nature and Natural Resources, 2007).

Table 11.2 shows the number of species that breed in New Zealand waters that have a threat ranking in the New Zealand Threat Classification System (Hitchmough et al, 2007; Molloy et al, 2002).

Table 11.2 shows the high proportion (62.3 per cent) of seabirds (excluding waders and shorebirds) that are threatened. Sixteen of the 22 acutely threatened species or subspecies and eight of the 14 chronically threatened species or subspecies are endemic to New Zealand.

Table 11.2 also highlights that, of the threatened species, certain marine fish groups such as sharks, skates, dogfish, and rays are particularly vulnerable to fishing pressures. This vulnerability results from their long lives and low reproductive rates. The great white shark and basking shark are the only marine fish in the chronically threatened category (Hitchmough et al, 2007). Sharks, skates, and dogfish are also a significant proportion of the species in the at risk category.

Both the North and South Island subspecies of Hector’s dolphin are acutely threatened.¹²

Table 11.2: Number of marine species and subspecies in the New Zealand Threat Classification System, 2005

View number of marine species and subspecies in the New Zealand Threat Classification System, 2005 (large table).

Changes in threat classification

The New Zealand Threat Classification lists are updated every three years. In 2005, several hundred species were added to the lists. For marine species, the total number of species in the acutely threatened, chronically threatened, or at risk categories has increased by one for marine fish, one for marine mammal, two for macroalgae, and 26 for marine invertebrates.

In general, this increase is likely to reflect better information and a growing understanding of the threat status of species in the New Zealand marine environment, rather than a real change in threat status. However, there are some genuine declines and recoveries.

Two species of seabird, the Campbell mollymawk and black petrel, have shown enough recovery to have their threat classification lowered. However, the threat status of seven species of seabird has worsened since 2004 (Hitchmough et al, 2007).

Table 11.3 shows the species of migratory marine mammals and seabirds in New Zealand waters that are on the IUCN Red List.

The New Zealand species on the IUCN Red List are the sei, blue, and fin whales (classified as endangered); and the humpback and sperm whales, snowy albatross, and southern giant petrel (classified as vulnerable).

Table 11.3: Migrant seabirds and marine mammals in critically endangered, endangered, and vulnerable IUCN Red List categories, 2005

Data source: Adapted from International Union for the Conservation of Nature and Natural Resources, 2007.

Causes of population loss within species

Fishing bycatch (the accidental capture of non-target species during fishing activities) is a significant cause of the decreasing numbers of many seabird species worldwide. In New Zealand, bycatch is a serious threat to New Zealand-breeding albatrosses and some petrels (Wilson, 2006).

Commercial and recreational set-net fishing also pose an unquantified threat to Hector’s dolphins and some penguins, shearwaters, and shags.

Recent initiatives to minimise the harm from bycatch include a national action plan to reduce seabird mortality and regulatory measures to address dolphin mortality.

Pest species and loss of habitat also present significant risks to breeding and nesting sites for many of our rare marine species.

Loss of genetic diversity is another risk faced by some species. Genetic diversity is an important factor in a species’ resilience. A significant reduction in population, from human or natural pressures, may affect a species’ ability to adapt to further environmental changes, especially large-scale variations such as climate change.

Marine areas with legal protection

Marine reserves

Around the world, marine reserves are widely considered to be useful for achieving marine conservation goals, including:

• conserving habitats

• maintaining marine communities

• fostering the recovery of some species.

Marine reserves cover slightly more than 7 per cent of New Zealand’s territorial sea. Ninety-nine per cent of this area is in two remote offshore marine reserves – the Kermadec Islands Marine Reserve and Auckland Islands Marine Reserve.

New Zealand’s first marine reserve (Cape Rodney–Okakari Point Marine Reserve) was established in 1975. There are now 31 gazetted marine reserves in New Zealand’s territorial sea, 15 of which have been established since 2000. The area designated as marine reserve has also increased significantly in the last decade, from 7,602 square kilometres in 1997 to 12,764 square kilometres in 2007.

Figure 11.8 shows the increase of marine reserve area in the territorial sea since 1974. There have been two large increases of marine reserve area, which can be attributed to the establishment of marine reserves in the two remote offshore island groups mentioned above. In 1990, 7,280 square kilometres were protected around the Kermadec Islands, and in 2003, 4,980 square kilometres were protected around the Auckland Islands. These two reserves make up 99 per cent of the total area protected by marine reserve.

Less than 1 per cent of marine reserve area lies around the three main islands of New Zealand (the North, South, and Stewart Islands).

Marine reserve recovery

Monitoring of marine reserves in New Zealand has provided us with useful insights into the effectiveness of protection and the changes that have occurred in New Zealand waters. It has also helped us understand how species targeted by fishing respond to protection.

Research has been carried out in three of New Zealand’s oldest and most-studied reserves situated in the northeast of New Zealand (Cape Rodney–Okakari Point Marine Reserve, Cathedral Cove–Te Whanganui a Hei Marine Reserve, and the ‘no-take’ Tāwharanui Marine Park). Results of this research show the recovery of previously overfished populations and the re-establishment of natural ecosystems (Langlois and Ballantine, 2005; Langlois et al, 2006).

Coastal Biogeographic Regions Classification

The Coastal Biogeographic Regions Classification divides New Zealand’s territorial sea into 13 regions. Figure 11.9 shows the location of these regions and compares them with marine reserves around New Zealand.

Of the 13 regions, nine have at least one marine reserve. However, only two have a significantly large area protected in a marine reserve: the Kermadec Islands and the Subantarctic Island regions. With 100 per cent and 41.9 per cent of their respective territorial sea ecosystems protected, these two regions are recognised internationally as unique ecosystems.

Figure 11.10 shows the proportion of mainland coastal biogeographic regions in designated marine reserves (none has more than 0.4 per cent). Four regions (Three Kings Islands, West Coast South Island, Snares Islands, and Chatham Islands) do not contain any marine reserves.