New Zealand’s commercial fisheries use a variety of different methods – some with more environmentally damaging impacts than others.
When making your seafood choice, ask how it was caught - avoid seafood caught by environmentally harmful methods.
Outlined here is Forest & Bird’s Best Fish Guide assessment of fishing methods, ranking them from least impacts (A) to most damaging impacts (E).
This represents one of the 6-criteria used to assess commercially caught seafood in New Zealand. For more information on the Best Fish Guide Assessment Methodology, click here.
| Fishing Type & Environmental Impact |
Score | Egs | |
|---|---|---|---|
 |
Hand collecting A highly targeted fishing method that has minimal impact. Collection and trampling in the inter-tidal zone may impact on inter-tidal communities. Can be a problem when intensive, but is more of a problem within recreational sectors. |
A if selective D if not selective |
e.g Pipi |
 |
Diving This is a preferable fishing method as it has minimal environmental impact and is highly targeted. However, if intensive, species can be over-harvested and entire coastlines striped of the resource. |
A if selective
D if not selective |
|
 |
Jigging Jigging is highly selective and takes minimal bycatch. It is often carried out at night to attract target to hooked lines. Discarded lines and lost jigs may have an impact on other sea life. |
A | e.g Squid |
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Handlining Handlining is not targeted. Unwanted or undersized fish may be killed as bycatch. Heavy fishing pressure can cause localised depletion of some species and collection of bait species from the shoreline (eg mussels) can affect inter-tidal communities in some areas. Discarded fishing line and hooks can entangle other marine life. |
B | e.g Snapper |
 |
Fyke Nets Fyke nets are selective, with some bycatch of other fish species. They are usually only used in freshwater environments. Shags can sometimes be trapped and drown in fyke nets. Habitat damage is minimal. |
B | e.g Eels |
 |
Trapping/Potting Fish traps and lobster pots are selective, with some bycatch of other fish species and octopus. Seals and shags can sometimes be trapped and drown in rock lobster pots, while seals, dolphins and whales have been known to get entangled in pot lines. Habitat damage is minimal, unless placed on fragile corals or other reef species. |
B | e.g Lobster |
 |
Trolling Trolling is a relatively selective method of catching large open water fish with few other species being caught. Fur seals, seabirds and sharks are occasionally hooked on trolls. Trolling uses smaller prey species as bait, so requires healthy and abundance stocks of those species. Trolling has minimal habitat damage. |
B | e.g Albacore Tuna |
 |
Purse Seining Purse seining usually targets single species schools in surface waters, and tends to be relatively selective. Dolphin captures are a problem in some international fisheries. It has negligible impact on the seafloor. |
B | e.g Pilchards, Kahawai |
 |
Beach Seining Beach seining has low selectivity, which varies with mesh size. It may have impacts on non-target coastal species. It may also have impacts on sensitive habitats. |
C | e.g Mullet |
 |
Danish Seining |
C-D | e.g Snapper |
 |
Pelagic (open water) longlines Longlines can be 10-80km long with multiple hooked lines (up to 3000 baited hooks). Longlining for tuna results in significant mortality of albatrosses and petrels as well as billfish and sharks. Inshore longlines set for species such as snapper also catch and kill petrels. Lost lines can also entangle and kill marine wildlife. Longlining uses a large amount of bait, potentially affecting these species. Released bait, if not native to New Zealand, may raise biosecurity problems. |
D | e.g Tuna |
 |
Bottom Longlines Bottom longlines may contain up to 15,000 hooks and are set to catch seafloor or deepwater species. Concerns include the impact on non-target, vulnerable deepwater species including sharks. Some seafloor impacts are also of concern. |
D | e.g Ling, Skates |
 |
Drop Longlining Similar to longlining, droplines run off a surface mainline and are used close to drop-offs. Droplining may impact deepwater species including sharks and has been associated with marine mammal interactions. |
D | e.g Bluenose |
 |
Trawling Trawling is the most common commercial fishing method in New Zealand. It involves nets ranging from 4-60m in height and stretching 150-200m in length can take enormous tonnages of bycatch. Protected species including sea lions, fur seals, dolphins and large sharks can be caught and drowned in nets, while albatross and other seabirds die hitting trawl wires. Midwater trawling in the water column has minimal seafloor impact. However, when midwater trawls are used at depth they often touch the bottom and can have similar impacts to bottom trawling |
D | e.g Hoki, Hake, Linh, Squid |
 |
Gillnetting Gillnetting (including set netting) can be highly unselective and has the potential to take large amounts of unwanted bycatch including dolphins, seals, sharks, seabirds and reef fish. The longer nets are left in the water, the lower survival of unwanted fish. |
D | e.g Flatfish, Butterfish, Sharks (e.g dogfish, elephant fish) |
 |
Pair Trawling Similar to bottom trawling, pair trawling involves two small vessels to drag and haul the trawl net, usually in shallower water. Significant volumes of unwanted bycatch are caught including protected species. Albatross and other seabirds are killed by striking the vessel to net wires (trawl warps). Gear contacting or near the seafloor causes major habitat and ecosystem damage. |
E | |
 |
Dredging Dredging targets species on or just below the seafloor. Like bottom trawling it causes significant habitat and ecosystem damage. As the gear is designed to dig into and drag along the seafloor, it effectively ploughs the seafloor destroying all marine life and habitats in its path. |
E | e.g Oysters, Scallops. |
 |
Bottom Trawling Bottom trawling, also a common commercial fishing method in New Zealand, is one of the most damaging fishing methods as it can take large quantities of unwanted bycatch including fish, sponges, corals, crabs, etc. Bycatch in some trawling operations can be up to 10 times the target species. Trawling also catches protected species including fur seals, sea lions and dolphins. Bottom trawl gear is dragged along the seafloor causing major habitat and ecosystem damage including species loss, decreased water clarity, seafloor smothering and habitat flattening. |
E | e.g Orange Roughy, Hoki, Deepwater dory/oreo |
